Control.cs source code in C# .NET

Source code for the .NET framework in C#

                        

Code:

/ 4.0 / 4.0 / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / WinForms / Managed / System / WinForms / Control.cs / 1305376 / Control.cs

                            #define DEBUG_PREFERREDSIZE 

//------------------------------------------------------------------------------
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved. 
// 
//----------------------------------------------------------------------------- 
 
[assembly: System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Performance", "CA1811:AvoidUncalledPrivateCode", Scope="member", Target="System.Windows.Forms.Control+ActiveXFontMarshaler..ctor()")]
[assembly: System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Security", "CA2122:DoNotIndirectlyExposeMethodsWithLinkDemands", Scope="member", Target="System.Windows.Forms.Control.PreProcessControlMessageInternal(System.Windows.Forms.Control, System.Windows.Forms.Message):System.Windows.Forms.PreProcessControlState")] 
[assembly: System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Security", "CA2122:DoNotIndirectlyExposeMethodsWithLinkDemands", Scope="member", Target="System.Windows.Forms.Control.OnPreviewKeyDown(System.Windows.Forms.PreviewKeyDownEventArgs):System.Void")]

/*
 */ 
namespace System.Windows.Forms {
    using Accessibility; 
    using Microsoft.Win32; 
    using System;
    using System.Collections; 
    using System.Collections.Specialized;
    using System.ComponentModel;
    using System.ComponentModel.Design;
    using System.ComponentModel.Design.Serialization; 
    using System.Configuration.Assemblies;
    using System.Diagnostics; 
    using System.Diagnostics.CodeAnalysis; 
    using System.Drawing;
    using System.Drawing.Drawing2D; 
    using System.Globalization;
    using System.Security.Permissions;
    using System.Security;
    using System.IO; 
    using System.Reflection;
    using System.Runtime.InteropServices; 
    using System.Runtime.InteropServices.ComTypes; 
    using System.Runtime.Remoting;
    using System.Runtime.Serialization; 
    using System.Runtime.Serialization.Formatters;
    using System.Runtime.Serialization.Formatters.Binary;
    using System.Text;
    using System.Threading; 
    using System.Windows.Forms.Design;
    using System.Windows.Forms.Internal; 
    using Encoding = System.Text.Encoding; 
    using System.Drawing.Imaging;
    using System.Windows.Forms.Layout; 
    using System.Runtime.Versioning;

    using IComDataObject = System.Runtime.InteropServices.ComTypes.IDataObject;
 
    /// 
    ///  
    ///    Defines the base class for controls, which are components 
    ///       with visual representation.
    ///  
    [
    ComVisible(true),
    ClassInterface(ClassInterfaceType.AutoDispatch),
    DefaultProperty("Text"), 
    DefaultEvent("Click"),
    Designer("System.Windows.Forms.Design.ControlDesigner, " + AssemblyRef.SystemDesign), 
    DesignerSerializer("System.Windows.Forms.Design.ControlCodeDomSerializer, " + AssemblyRef.SystemDesign, "System.ComponentModel.Design.Serialization.CodeDomSerializer, " + AssemblyRef.SystemDesign), 
    ToolboxItemFilter("System.Windows.Forms")
    ] 
    public partial class Control :
    Component,
    UnsafeNativeMethods.IOleControl,
    UnsafeNativeMethods.IOleObject, 
    UnsafeNativeMethods.IOleInPlaceObject,
    UnsafeNativeMethods.IOleInPlaceActiveObject, 
    UnsafeNativeMethods.IOleWindow, 
    UnsafeNativeMethods.IViewObject,
    UnsafeNativeMethods.IViewObject2, 
    UnsafeNativeMethods.IPersist,
    UnsafeNativeMethods.IPersistStreamInit,
    UnsafeNativeMethods.IPersistPropertyBag,
    UnsafeNativeMethods.IPersistStorage, 
    UnsafeNativeMethods.IQuickActivate,
    ISupportOleDropSource, 
    IDropTarget, 
    ISynchronizeInvoke,
    IWin32Window, 
    IArrangedElement,
    IBindableComponent {

#if FINALIZATION_WATCH 
        static readonly TraceSwitch ControlFinalization = new TraceSwitch("ControlFinalization", "Tracks the creation and destruction of finalization");
        internal static string GetAllocationStack() { 
            if (ControlFinalization.TraceVerbose) { 
                // SECREVIEW: This assert is safe, the operation is safe (data obtained from the CLR). This code is for debugging purposes only.
                // Tracked by VSWhidbey #426446. 
                new EnvironmentPermission(PermissionState.Unrestricted).Assert();
                try {
                    return Environment.StackTrace;
                } 
                    finally {
                        CodeAccessPermission.RevertAssert(); 
                    } 
                }
            else { 
                return "Enable 'ControlFinalization' switch to see stack of allocation";
            }

        } 
        private string allocationSite = Control.GetAllocationStack();
#endif 
 
#if DEBUG
        internal static readonly TraceSwitch PaletteTracing = new TraceSwitch("PaletteTracing", "Debug Palette code"); 
        internal static readonly TraceSwitch ControlKeyboardRouting = new TraceSwitch("ControlKeyboardRouting", "Debug Keyboard routing for controls");
        internal static readonly TraceSwitch FocusTracing = new TraceSwitch("FocusTracing", "Debug focus/active control/enter/leave");
        private static readonly BooleanSwitch AssertOnControlCreateSwitch = new BooleanSwitch("AssertOnControlCreate", "Assert when anything directly deriving from control is created.");
        internal static readonly BooleanSwitch TraceMnemonicProcessing = new BooleanSwitch("TraceCanProcessMnemonic", "Trace mnemonic processing calls to assure right child-parent call ordering."); 

        internal void TraceCanProcessMnemonic(){ 
            if( TraceMnemonicProcessing.Enabled ){ 
            string str;
                try { 
                    str = string.Format( CultureInfo.CurrentCulture, "{0}<{1}>", this.GetType().Name, this.Text );
                    int maxFrameCount = new StackTrace().FrameCount;
                    if (maxFrameCount > 5) {
                        maxFrameCount = 5; 
                    }
                    int frameIndex = 1; 
                    while( frameIndex < maxFrameCount) { 
                        StackFrame sf = new StackFrame(frameIndex);
                        if( frameIndex == 2 && sf.GetMethod().Name.Equals("CanProcessMnemonic") ){ // log immediate call if in a virtual/recursive call. 
                            break;
                        }
                        str += new StackTrace(sf).ToString().TrimEnd();
                        frameIndex++; 
                    }
                    if( frameIndex > 2 ){ // new CanProcessMnemonic virtual/recursive call stack. 
                        str = "\r\n" + str; 
                    }
                } 
                catch (Exception ex) {
                    str = ex.ToString();
                }
                Debug.WriteLine( str ); 
            }
        } 
#else 
        internal static readonly TraceSwitch ControlKeyboardRouting;
        internal static readonly TraceSwitch PaletteTracing; 
        internal static readonly TraceSwitch FocusTracing;
#endif

#if DEBUG 
        internal static readonly BooleanSwitch BufferPinkRect = new BooleanSwitch("BufferPinkRect", "Renders a pink rectangle with painting double buffered controls");
        internal static readonly BooleanSwitch BufferDisabled = new BooleanSwitch("BufferDisabled", "Makes double buffered controls non-double buffered"); 
#else 
        internal static readonly BooleanSwitch BufferPinkRect;
#endif 

        private static int WM_GETCONTROLNAME;
        private static int WM_GETCONTROLTYPE;
 
        static Control() {
            WM_GETCONTROLNAME = SafeNativeMethods.RegisterWindowMessage("WM_GETCONTROLNAME"); 
            WM_GETCONTROLTYPE = SafeNativeMethods.RegisterWindowMessage("WM_GETCONTROLTYPE"); 

        } 

        internal const int STATE_CREATED                = 0x00000001;
        internal const int STATE_VISIBLE                = 0x00000002;
        internal const int STATE_ENABLED                = 0x00000004; 
        internal const int STATE_TABSTOP                = 0x00000008;
        internal const int STATE_RECREATE               = 0x00000010; 
        internal const int STATE_MODAL                  = 0x00000020; 
        internal const int STATE_ALLOWDROP              = 0x00000040;
        internal const int STATE_DROPTARGET             = 0x00000080; 
        internal const int STATE_NOZORDER               = 0x00000100;
        internal const int STATE_LAYOUTDEFERRED         = 0x00000200;
        internal const int STATE_USEWAITCURSOR          = 0x00000400;
        internal const int STATE_DISPOSED               = 0x00000800; 
        internal const int STATE_DISPOSING              = 0x00001000;
        internal const int STATE_MOUSEENTERPENDING      = 0x00002000; 
        internal const int STATE_TRACKINGMOUSEEVENT     = 0x00004000; 
        internal const int STATE_THREADMARSHALLPENDING  = 0x00008000;
        internal const int STATE_SIZELOCKEDBYOS         = 0x00010000; 
        internal const int STATE_CAUSESVALIDATION       = 0x00020000;
        internal const int STATE_CREATINGHANDLE         = 0x00040000;
        internal const int STATE_TOPLEVEL               = 0x00080000;
        internal const int STATE_ISACCESSIBLE           = 0x00100000; 
        internal const int STATE_OWNCTLBRUSH            = 0x00200000;
        internal const int STATE_EXCEPTIONWHILEPAINTING = 0x00400000; 
        internal const int STATE_LAYOUTISDIRTY          = 0x00800000; 
        internal const int STATE_CHECKEDHOST            = 0x01000000;
        internal const int STATE_HOSTEDINDIALOG         = 0x02000000; 
        internal const int STATE_DOUBLECLICKFIRED       = 0x04000000;
        internal const int STATE_MOUSEPRESSED           = 0x08000000;
        internal const int STATE_VALIDATIONCANCELLED    = 0x10000000;
        internal const int STATE_PARENTRECREATING       = 0x20000000; 
        internal const int STATE_MIRRORED               = 0x40000000;
 
        // HACK HACK HACK - when we change RightToLeft, we need to change the scrollbar thumb. 
        // We can't do that until after the control has been created, and all the items added
        // back. This is because the system control won't know the nMin and nMax of the scroll 
        // bar until the items are added. So in RightToLeftChanged, we set a flag that indicates
        // that we want to set the scroll position. In OnHandleCreated we check this flag,
        // and if set, we BeginInvoke. We have to BeginInvoke since we have to wait until the items
        // are added. We only want to do this when RightToLeft changes thus the flags 
        // STATE2_HAVEINVOKED and STATE2_SETSCROLLPOS. Otherwise we would do this on each HandleCreated.
        private  const int STATE2_HAVEINVOKED                       = 0x00000001; 
        private  const int STATE2_SETSCROLLPOS                      = 0x00000002; 
        private  const int STATE2_LISTENINGTOUSERPREFERENCECHANGED  = 0x00000004;   // set when the control is listening to SystemEvents.UserPreferenceChanged.
        internal const int STATE2_INTERESTEDINUSERPREFERENCECHANGED = 0x00000008;   // if set, the control will listen to SystemEvents.UserPreferenceChanged when TopLevel is true and handle is created. 
        internal const int STATE2_MAINTAINSOWNCAPTUREMODE           = 0x00000010;   // if set, the control DOES NOT necessarily take capture on MouseDown
        private  const int STATE2_BECOMINGACTIVECONTROL             = 0x00000020;   // set to true by ContainerControl when this control is becoming its active control

        private  const int STATE2_CLEARLAYOUTARGS                   = 0x00000040;   // if set, the next time PerformLayout is called, cachedLayoutEventArg will be cleared. 
        private  const int STATE2_INPUTKEY                          = 0x00000080;
        private  const int STATE2_INPUTCHAR                         = 0x00000100; 
        private  const int STATE2_UICUES                            = 0x00000200; 
        private  const int STATE2_ISACTIVEX                         = 0x00000400;
        internal const int STATE2_USEPREFERREDSIZECACHE             = 0x00000800; 

        private static readonly object EventAutoSizeChanged           = new object();
        private static readonly object EventKeyDown                   = new object();
        private static readonly object EventKeyPress                  = new object(); 
        private static readonly object EventKeyUp                     = new object();
        private static readonly object EventMouseDown                 = new object(); 
        private static readonly object EventMouseEnter                = new object(); 
        private static readonly object EventMouseLeave                = new object();
        private static readonly object EventMouseHover                = new object(); 
        private static readonly object EventMouseMove                 = new object();
        private static readonly object EventMouseUp                   = new object();
        private static readonly object EventMouseWheel                = new object();
        private static readonly object EventClick                     = new object(); 
        private static readonly object EventClientSize                = new object();
        private static readonly object EventDoubleClick               = new object(); 
        private static readonly object EventMouseClick                = new object(); 
        private static readonly object EventMouseDoubleClick          = new object();
        private static readonly object EventMouseCaptureChanged       = new object(); 
        private static readonly object EventMove                      = new object();
        private static readonly object EventResize                    = new object();
        private static readonly object EventLayout                    = new object();
        private static readonly object EventGotFocus                  = new object(); 
        private static readonly object EventLostFocus                 = new object();
        private static readonly object EventEnabledChanged            = new object(); 
        private static readonly object EventEnter                     = new object(); 
        private static readonly object EventLeave                     = new object();
        private static readonly object EventHandleCreated             = new object(); 
        private static readonly object EventHandleDestroyed           = new object();
        private static readonly object EventVisibleChanged            = new object();
        private static readonly object EventControlAdded              = new object();
        private static readonly object EventControlRemoved            = new object(); 
        private static readonly object EventChangeUICues              = new object();
        private static readonly object EventSystemColorsChanged       = new object(); 
        private static readonly object EventValidating                = new object(); 
        private static readonly object EventValidated                 = new object();
        private static readonly object EventStyleChanged              = new object(); 
        private static readonly object EventImeModeChanged            = new object();
        private static readonly object EventHelpRequested             = new object();
        private static readonly object EventPaint                     = new object();
        private static readonly object EventInvalidated               = new object(); 
        private static readonly object EventQueryContinueDrag         = new object();
        private static readonly object EventGiveFeedback              = new object(); 
        private static readonly object EventDragEnter                 = new object(); 
        private static readonly object EventDragLeave                 = new object();
        private static readonly object EventDragOver                  = new object(); 
        private static readonly object EventDragDrop                  = new object();
        private static readonly object EventQueryAccessibilityHelp    = new object();
        private static readonly object EventBackgroundImage           = new object();
        private static readonly object EventBackgroundImageLayout     = new object(); 
        private static readonly object EventBindingContext            = new object();
        private static readonly object EventBackColor                 = new object(); 
        private static readonly object EventParent                    = new object(); 
        private static readonly object EventVisible                   = new object();
        private static readonly object EventText                      = new object(); 
        private static readonly object EventTabStop                   = new object();
        private static readonly object EventTabIndex                  = new object();
        private static readonly object EventSize                      = new object();
        private static readonly object EventRightToLeft               = new object(); 
        private static readonly object EventLocation                  = new object();
        private static readonly object EventForeColor                 = new object(); 
        private static readonly object EventFont                      = new object(); 
        private static readonly object EventEnabled                   = new object();
        private static readonly object EventDock                      = new object(); 
        private static readonly object EventCursor                    = new object();
        private static readonly object EventContextMenu               = new object();
        private static readonly object EventContextMenuStrip          = new object();
        private static readonly object EventCausesValidation          = new object(); 
        private static readonly object EventRegionChanged             = new object();
        private static readonly object EventMarginChanged             = new object(); 
        internal static readonly object EventPaddingChanged           = new object(); 
        private static readonly object EventPreviewKeyDown            = new object();
 
        #if WIN95_SUPPORT
        private static int mouseWheelMessage = NativeMethods.WM_MOUSEWHEEL;
        private static bool mouseWheelRoutingNeeded;
        private static bool mouseWheelInit; 
        #endif
 
        private static int threadCallbackMessage; 

        // Initially check for illegal multithreading based on whether the 
        // debugger is attached.
        [ResourceExposure(ResourceScope.Process)]
        private static bool checkForIllegalCrossThreadCalls = Debugger.IsAttached;
        private static ContextCallback invokeMarshaledCallbackHelperDelegate; 

        [ ThreadStatic ] 
        private static bool inCrossThreadSafeCall = false; 

// disable csharp compiler warning #0414: field assigned unused value 
#pragma warning disable 0414
        [ ThreadStatic ]
        internal static HelpInfo currentHelpInfo = null;
#pragma warning restore 0414 

        private static FontHandleWrapper defaultFontHandleWrapper; 
 
        private const short PaintLayerBackground = 1;
        private const short PaintLayerForeground = 2; 

        private const byte RequiredScalingEnabledMask = 0x10;
        private const byte RequiredScalingMask = 0x0F;
 
        private static Font defaultFont;
 
        // Property store keys for properties.  The property store allocates most efficiently 
        // in groups of four, so we try to lump properties in groups of four based on how
        // likely they are going to be used in a group. 
        //
        private static readonly int PropName                                = PropertyStore.CreateKey();
        private static readonly int PropBackBrush                           = PropertyStore.CreateKey();
        private static readonly int PropFontHeight                          = PropertyStore.CreateKey(); 
        private static readonly int PropCurrentAmbientFont                  = PropertyStore.CreateKey();
 
        private static readonly int PropControlsCollection                  = PropertyStore.CreateKey(); 
        private static readonly int PropBackColor                           = PropertyStore.CreateKey();
        private static readonly int PropForeColor                           = PropertyStore.CreateKey(); 
        private static readonly int PropFont                                = PropertyStore.CreateKey();

        private static readonly int PropBackgroundImage                     = PropertyStore.CreateKey();
        private static readonly int PropFontHandleWrapper                   = PropertyStore.CreateKey(); 
        private static readonly int PropUserData                            = PropertyStore.CreateKey();
        private static readonly int PropContextMenu                         = PropertyStore.CreateKey(); 
 
        private static readonly int PropCursor                              = PropertyStore.CreateKey();
        private static readonly int PropRegion                              = PropertyStore.CreateKey(); 
        private static readonly int PropRightToLeft                         = PropertyStore.CreateKey();

        private static readonly int PropBindings                            = PropertyStore.CreateKey();
        private static readonly int PropBindingManager                      = PropertyStore.CreateKey(); 
        private static readonly int PropAccessibleDefaultActionDescription  = PropertyStore.CreateKey();
        private static readonly int PropAccessibleDescription               = PropertyStore.CreateKey(); 
 
        private static readonly int PropAccessibility                       = PropertyStore.CreateKey();
        private static readonly int PropNcAccessibility                     = PropertyStore.CreateKey(); 
        private static readonly int PropAccessibleName                      = PropertyStore.CreateKey();
        private static readonly int PropAccessibleRole                      = PropertyStore.CreateKey();

        private static readonly int PropPaintingException                   = PropertyStore.CreateKey(); 
        private static readonly int PropActiveXImpl                         = PropertyStore.CreateKey();
        private static readonly int PropControlVersionInfo                  = PropertyStore.CreateKey(); 
        private static readonly int PropBackgroundImageLayout               = PropertyStore.CreateKey(); 

        private static readonly int PropAccessibleHelpProvider              = PropertyStore.CreateKey(); 
        private static readonly int PropContextMenuStrip                    = PropertyStore.CreateKey();
        private static readonly int PropAutoScrollOffset                    = PropertyStore.CreateKey();
        private static readonly int PropUseCompatibleTextRendering          = PropertyStore.CreateKey();
 
        private static readonly int PropImeWmCharsToIgnore                  = PropertyStore.CreateKey();
        private static readonly int PropImeMode                             = PropertyStore.CreateKey(); 
        private static readonly int PropDisableImeModeChangedCount          = PropertyStore.CreateKey(); 
        private static readonly int PropLastCanEnableIme                    = PropertyStore.CreateKey();
 
        private static readonly int PropCacheTextCount                      = PropertyStore.CreateKey();
        private static readonly int PropCacheTextField                      = PropertyStore.CreateKey();
        private static readonly int PropAmbientPropertiesService            = PropertyStore.CreateKey();
 

        // This switch determines the default text rendering engine to use by some controls that support switching rendering engine. 
        // CheckedListBox, PropertyGrid, GroupBox, Label and LinkLabel, and ButtonBase controls. 
        // True means use GDI+, false means use GDI (TextRenderer).
        internal static bool UseCompatibleTextRenderingDefault = true; 

        ///////////////////////////////////////////////////////////////////////
        // Control per instance members
        // 
        // Note: Do not add anything to this list unless absolutely neccessary.
        //       Every control on a form has the overhead of all of these 
        //       variables! 
        //
        // Begin Members { 

        // List of properties that are generally set, so we keep them directly on
        // control.
        // 

        // Resist the temptation to make this variable 'internal' rather than 
        // private. Handle access should be tightly controlled, and is in this 
        // file.  Making it 'internal' makes controlling it quite difficult.
        private ControlNativeWindow           window; 

        private Control                       parent;
        private Control                       reflectParent;
        private CreateParams                  createParams; 
        private int                           x;                      //
        private int                           y; 
        private int                           width; 
        private int                           height;
        private int                           clientWidth; 
        private int                           clientHeight;
        private int                           state;                  // See STATE_ constants above
        private int                           state2;                 // See STATE2_ constants above
        private ControlStyles                 controlStyle;           // User supplied control style 
        private int                           tabIndex;
        private string                        text;                   // See ControlStyles.CacheText for usage notes 
        private byte                          layoutSuspendCount; 
        private byte                          requiredScaling;        // bits 0-4: BoundsSpecified stored in RequiredScaling property.  Bit 5: RequiredScalingEnabled property.
        private PropertyStore                 propertyStore;          // Contains all properties that are not always set. 
        private NativeMethods.TRACKMOUSEEVENT trackMouseEvent;
        private short                         updateCount;
        private LayoutEventArgs               cachedLayoutEventArgs;
        private Queue                         threadCallbackList; 

        // for keeping track of our ui state for focus and keyboard cues.  using a member variable 
        // here because we hit this a lot 
        //
        private int uiCuesState; 

        private const int UISTATE_FOCUS_CUES_MASK               = 0x000F;
        private const int UISTATE_FOCUS_CUES_HIDDEN             = 0x0001;
        private const int UISTATE_FOCUS_CUES_SHOW               = 0x0002; 
        private const int UISTATE_KEYBOARD_CUES_MASK            = 0x00F0;
        private const int UISTATE_KEYBOARD_CUES_HIDDEN          = 0x0010; 
        private const int UISTATE_KEYBOARD_CUES_SHOW            = 0x0020; 

        // } End Members 
        ///////////////////////////////////////////////////////////////////////

#if DEBUG
        internal int LayoutSuspendCount { 
            get { return layoutSuspendCount; }
        } 
 
        internal void AssertLayoutSuspendCount(int value) {
            Debug.Assert(value == layoutSuspendCount, "Suspend/Resume layout mismatch!"); 
        }

/*
example usage 

#if DEBUG 
        int dbgLayoutCheck = LayoutSuspendCount; 
#endif
#if DEBUG 
        AssertLayoutSuspendCount(dbgLayoutCheck);
#endif
*/
 
#endif
 
        ///  
        /// 
        /// Initializes a new instance of the  class. 
        /// 
        public Control() : this(true) {
        }
 
        /// 
        ///  
        internal Control(bool autoInstallSyncContext) : base() { 
#if DEBUG
            if (AssertOnControlCreateSwitch.Enabled) { 
                Debug.Assert(this.GetType().BaseType != typeof(Control), "Direct derivative of Control Created: " + this.GetType().FullName);
                Debug.Assert(this.GetType() != typeof(Control), "Control Created!");
            }
#endif 
            propertyStore = new PropertyStore();
 
            window = new ControlNativeWindow(this); 
            RequiredScalingEnabled = true;
            RequiredScaling = BoundsSpecified.All; 
            tabIndex = -1;

            state = STATE_VISIBLE | STATE_ENABLED | STATE_TABSTOP | STATE_CAUSESVALIDATION;
            state2 = STATE2_INTERESTEDINUSERPREFERENCECHANGED; 
            SetStyle(ControlStyles.AllPaintingInWmPaint |
                     ControlStyles.UserPaint | 
                     ControlStyles.StandardClick | 
                     ControlStyles.StandardDoubleClick |
                     ControlStyles.UseTextForAccessibility | 
                     ControlStyles.Selectable,true);

#if WIN95_SUPPORT
            InitMouseWheelSupport(); 
#endif
 
            // We baked the "default default" margin and min size into CommonProperties 
            // so that in the common case the PropertyStore would be empty.  If, however,
            // someone overrides these Default* methads, we need to write the default 
            // value into the PropertyStore in the ctor.
            //
            if(DefaultMargin != CommonProperties.DefaultMargin) {
                Margin = DefaultMargin; 
            }
            if(DefaultMinimumSize != CommonProperties.DefaultMinimumSize) { 
                MinimumSize = DefaultMinimumSize; 
            }
            if(DefaultMaximumSize != CommonProperties.DefaultMaximumSize) { 
                MaximumSize = DefaultMaximumSize;
            }

            // Compute our default size. 
            //
            Size defaultSize = DefaultSize; 
            width = defaultSize.Width; 
            height = defaultSize.Height;
 
            // DefaultSize may have hit GetPreferredSize causing a PreferredSize to be cached.  The
            // PreferredSize may change as a result of the current size.  Since a  SetBoundsCore did
            // not happen, so we need to clear the preferredSize cache manually.
            CommonProperties.xClearPreferredSizeCache(this); 

            if (width != 0 && height != 0) { 
                NativeMethods.RECT rect = new NativeMethods.RECT(); 
                rect.left = rect.right = rect.top = rect.bottom = 0;
 
                CreateParams cp = CreateParams;

                SafeNativeMethods.AdjustWindowRectEx(ref rect, cp.Style, false, cp.ExStyle);
                clientWidth = width - (rect.right - rect.left); 
                clientHeight = height - (rect.bottom - rect.top);
            } 
 

            // Set up for async operations on this thread. 
            if (autoInstallSyncContext) {
                WindowsFormsSynchronizationContext.InstallIfNeeded();
            }
        } 

        ///  
        ///  
        /// Initializes a new instance of the  class.
        ///  
        public Control( string text ) : this( (Control) null, text ) {
        }

        ///  
        /// 
        /// Initializes a new instance of the  class. 
        ///  
        public Control( string text, int left, int top, int width, int height ) :
                    this( (Control) null, text, left, top, width, height ) { 
        }

        /// 
        ///  
        /// Initializes a new instance of the  class.
        ///  
        public Control( Control parent, string text ) : this() { 
            this.Parent = parent;
            this.Text = text; 
        }

        /// 
        ///  
        /// Initializes a new instance of the  class.
        ///  
        public Control( Control parent, string text, int left, int top, int width, int height ) : this( parent, text ) { 
            this.Location = new Point( left, top );
            this.Size = new Size( width, height ); 
        }

        /// 
        ///  
        ///      The Accessibility Object for this Control
        ///  
        [ 
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden), 
        SRDescription(SR.ControlAccessibilityObjectDescr)
        ]
        public AccessibleObject AccessibilityObject {
            get { 
                AccessibleObject accessibleObject = (AccessibleObject)Properties.GetObject(PropAccessibility);
                if (accessibleObject == null) { 
                    accessibleObject = CreateAccessibilityInstance(); 
                    // this is a security check. we want to enforce that we only return
                    // ControlAccessibleObject and not some other derived class 
                    if(!(accessibleObject is ControlAccessibleObject)) {
                        Debug.Fail("Accessible objects for controls must be derived from ControlAccessibleObject.");
                        return null;
                    } 
                    Properties.SetObject(PropAccessibility, accessibleObject);
                } 
 
                Debug.Assert(accessibleObject != null, "Failed to create accessibility object");
                return accessibleObject; 
            }
        }

        ///  
        ///      Private accessibility object for control, used to wrap the object that
        ///      OLEACC.DLL creates to represent the control's non-client (NC) region. 
        ///  
        private AccessibleObject NcAccessibilityObject {
            get { 
                AccessibleObject ncAccessibleObject = (AccessibleObject)Properties.GetObject(PropNcAccessibility);
                if (ncAccessibleObject == null) {
                    ncAccessibleObject = new ControlAccessibleObject(this, NativeMethods.OBJID_WINDOW);
                    Properties.SetObject(PropNcAccessibility, ncAccessibleObject); 
                }
 
                Debug.Assert(ncAccessibleObject != null, "Failed to create NON-CLIENT accessibility object"); 
                return ncAccessibleObject;
            } 
        }

        /// 
        ///     Returns a specific AccessibleObject associated with this 
        ///     control, based on standard "accessibile object id".
        ///  
        ///  
        private AccessibleObject GetAccessibilityObject(int accObjId) {
            AccessibleObject accessibleObject; 

            switch (accObjId) {
                case NativeMethods.OBJID_CLIENT:
                    accessibleObject = this.AccessibilityObject; 
                    break;
                case NativeMethods.OBJID_WINDOW: 
                    accessibleObject = this.NcAccessibilityObject; 
                    break;
                default: 
                    if (accObjId > 0) {
                        accessibleObject = this.GetAccessibilityObjectById(accObjId);
                    } else {
                        accessibleObject = null; 
                    }
                    break; 
            } 

            return accessibleObject; 
        }

        /// 
        ///  
        ///      Returns a specific AccessibleObbject associated w/ the objectID
        ///  
        protected virtual AccessibleObject GetAccessibilityObjectById(int objectId) { 
            return null;
        } 

        /// 
        /// 
        ///      The default action description of the control 
        /// 
        [ 
        SRCategory(SR.CatAccessibility), 
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden), 
        SRDescription(SR.ControlAccessibleDefaultActionDescr)
        ]
        public string AccessibleDefaultActionDescription {
            get { 
                return (string)Properties.GetObject(PropAccessibleDefaultActionDescription);
            } 
            set { 
                Properties.SetObject(PropAccessibleDefaultActionDescription, value);
            } 
        }

        /// 
        ///  
        ///      The accessible description of the control
        ///  
        [ 
        SRCategory(SR.CatAccessibility),
        DefaultValue(null), 
        Localizable(true),
        SRDescription(SR.ControlAccessibleDescriptionDescr)
        ]
        public string AccessibleDescription { 
            get {
                return (string)Properties.GetObject(PropAccessibleDescription); 
            } 
            set {
                Properties.SetObject(PropAccessibleDescription, value); 
            }
        }

        ///  
        /// 
        ///      The accessible name of the control 
        ///  
        [
        SRCategory(SR.CatAccessibility), 
        DefaultValue(null),
        Localizable(true),
        SRDescription(SR.ControlAccessibleNameDescr)
        ] 
        public string AccessibleName {
            get { 
                return (string)Properties.GetObject(PropAccessibleName); 
            }
 
            set {
                Properties.SetObject(PropAccessibleName, value);
            }
        } 

        ///  
        ///  
        ///      The accessible role of the control
        ///  
        [
        SRCategory(SR.CatAccessibility),
        DefaultValue(AccessibleRole.Default),
        SRDescription(SR.ControlAccessibleRoleDescr) 
        ]
        public AccessibleRole AccessibleRole { 
 
            get {
                bool found; 
                int role = Properties.GetInteger(PropAccessibleRole, out found);
                if (found) {
                    return (AccessibleRole)role;
                } 
                else {
                    return AccessibleRole.Default; 
                } 
            }
 
            set {
                //valid values are -1 to 0x40
                if (!ClientUtils.IsEnumValid(value, (int)value, (int)AccessibleRole.Default, (int)AccessibleRole.OutlineButton)) {
                    throw new InvalidEnumArgumentException("value", (int)value, typeof(AccessibleRole)); 
                }
                Properties.SetInteger(PropAccessibleRole, (int)value); 
            } 
        }
 
        /// 
        ///     Helper method for retrieving an ActiveX property.  We abstract these
        ///     to another method so we do not force JIT the ActiveX codebase.
        ///  
        private Color ActiveXAmbientBackColor {
            get { 
                return ActiveXInstance.AmbientBackColor; 
            }
        } 

        /// 
        ///     Helper method for retrieving an ActiveX property.  We abstract these
        ///     to another method so we do not force JIT the ActiveX codebase. 
        /// 
        private Color ActiveXAmbientForeColor { 
            get { 
                return ActiveXInstance.AmbientForeColor;
            } 
        }

        /// 
        ///     Helper method for retrieving an ActiveX property.  We abstract these 
        ///     to another method so we do not force JIT the ActiveX codebase.
        ///  
        private Font ActiveXAmbientFont { 
            [ResourceExposure(ResourceScope.Process)]
            [ResourceConsumption(ResourceScope.Process)] 
            get {
                return ActiveXInstance.AmbientFont;
            }
        } 

        ///  
        ///     Helper method for retrieving an ActiveX property.  We abstract these 
        ///     to another method so we do not force JIT the ActiveX codebase.
        ///  
        private bool ActiveXEventsFrozen {
            get {
                return ActiveXInstance.EventsFrozen;
            } 
        }
 
        ///  
        ///     Helper method for retrieving an ActiveX property.  We abstract these
        ///     to another method so we do not force JIT the ActiveX codebase. 
        /// 
        private IntPtr ActiveXHWNDParent {
            get {
                return ActiveXInstance.HWNDParent; 
            }
        } 
 
        /// 
        ///      Retrieves the ActiveX control implementation for 
        ///      this control.  This will demand create the implementation
        ///      if it does not already exist.
        /// 
        private ActiveXImpl ActiveXInstance { 
            get {
                ActiveXImpl activeXImpl = (ActiveXImpl)Properties.GetObject(PropActiveXImpl); 
                if (activeXImpl == null) { 

                    // Don't allow top level objects to be hosted 
                    // as activeX controls.
                    //
                    if (GetState(STATE_TOPLEVEL)) {
                        throw new NotSupportedException(SR.GetString(SR.AXTopLevelSource)); 
                    }
 
                    activeXImpl = new ActiveXImpl(this); 

                    // PERF: IsActiveX is called quite a bit - checked everywhere from sizing to event raising.  Using a state 
                    // bit to track PropActiveXImpl instead of fetching from the property store.
                    SetState2(STATE2_ISACTIVEX, true);
                    Properties.SetObject(PropActiveXImpl, activeXImpl);
                } 

                return activeXImpl; 
            } 
        }
 
        /// 
        /// 
        ///     The AllowDrop property. If AllowDrop is set to true then
        ///     this control will allow drag and drop operations and events to be used. 
        /// 
        [ 
        SRCategory(SR.CatBehavior), 
        DefaultValue(false),
        SRDescription(SR.ControlAllowDropDescr) 
        ]
        public virtual bool AllowDrop {
            get {
                return GetState(STATE_ALLOWDROP); 
            }
 
            set { 
                if (GetState(STATE_ALLOWDROP) != value) {
                    // Since we won't call SetAcceptDrops without a handle, 
                    // we do the security demand here. Without this demand
                    // we are still safe, but you get the exception at an
                    // odd time. This gives a better experience.
                    // 
                    if (value && !IsHandleCreated) {
                        IntSecurity.ClipboardRead.Demand(); 
                    } 

                    SetState(STATE_ALLOWDROP, value); 

                    if (IsHandleCreated) {
                        try {
                            SetAcceptDrops(value); 
                        }
                        catch { 
                            // If there is an error, back out the AllowDrop state... 
                            //
                            SetState(STATE_ALLOWDROP, !value); 
                            throw;
                        }
                    }
                } 
            }
        } 
 
        // Queries the Site for AmbientProperties.  May return null.
        // Do not confuse with inheritedProperties -- the service is turned to 
        // after we've exhausted inheritedProperties.
        private AmbientProperties AmbientPropertiesService {
            get {
                bool contains; 
                AmbientProperties props = (AmbientProperties)Properties.GetObject(PropAmbientPropertiesService, out contains);
                if (!contains) { 
                    if (Site != null) { 
                        props = (AmbientProperties)Site.GetService(typeof(AmbientProperties));
                    } 
                    else {
                        props = (AmbientProperties)GetService(typeof(AmbientProperties));
                    }
 
                    if (props != null) {
                        Properties.SetObject(PropAmbientPropertiesService, props); 
                    } 
                }
                return props; 
            }
        }

        ///  
        /// 
        ///     The current value of the anchor property. The anchor property 
        ///     determines which edges of the control are anchored to the container's 
        ///     edges.
        ///  
        [
        SRCategory(SR.CatLayout),
        Localizable(true),
        DefaultValue(CommonProperties.DefaultAnchor), 
        SRDescription(SR.ControlAnchorDescr),
        RefreshProperties(RefreshProperties.Repaint) 
        ] 
        public virtual AnchorStyles Anchor {
            get { 
                return DefaultLayout.GetAnchor(this);
            }
            set {
                DefaultLayout.SetAnchor(ParentInternal, this, value); 
            }
        } 
 
        /// 
        [SRCategory(SR.CatLayout)] 
        [RefreshProperties(RefreshProperties.All)]
        [Localizable(true)]
        [DefaultValue(CommonProperties.DefaultAutoSize)]
        [SRDescription(SR.ControlAutoSizeDescr)] 
        [Browsable(false), EditorBrowsable(EditorBrowsableState.Never),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)] 
        public virtual bool AutoSize { 
            get { return CommonProperties.GetAutoSize(this); }
            set { 
                if(value != AutoSize) {
                    CommonProperties.SetAutoSize(this, value);
                    if(ParentInternal != null) {
                        // DefaultLayout does not keep anchor information until it needs to.  When 
                        // AutoSize became a common property, we could no longer blindly call into
                        // DefaultLayout, so now we do a special InitLayout just for DefaultLayout. 
                        if(value && ParentInternal.LayoutEngine == DefaultLayout.Instance) { 
                            ParentInternal.LayoutEngine.InitLayout(this, BoundsSpecified.Size);
                        } 
                        LayoutTransaction.DoLayout(ParentInternal, this, PropertyNames.AutoSize);
                    }

                    OnAutoSizeChanged(EventArgs.Empty); 
                }
            } 
        } 

 
        /// 
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlOnAutoSizeChangedDescr)]
        [Browsable(false), EditorBrowsable(EditorBrowsableState.Never)]
        public event EventHandler AutoSizeChanged { 
            add {
                Events.AddHandler(EventAutoSizeChanged, value); 
            } 
            remove {
                Events.RemoveHandler(EventAutoSizeChanged, value); 
            }
        }

        ///  
        /// Controls the location of where this control is scrolled to in ScrollableControl.ScrollControlIntoView.
        /// Default is the upper left hand corner of the control. 
        ///  
        [
        Browsable(false), 
        EditorBrowsable(EditorBrowsableState.Advanced),
        DefaultValue(typeof(Point), "0, 0")
        ]
        public virtual Point AutoScrollOffset { 
            get {
                if (Properties.ContainsObject(PropAutoScrollOffset)) { 
                    return (Point)Properties.GetObject(PropAutoScrollOffset); 
                }
                return Point.Empty; 
            }
            set {
                if (AutoScrollOffset != value) {
                    Properties.SetObject(PropAutoScrollOffset, value); 
                }
            } 
        } 

        protected void SetAutoSizeMode(AutoSizeMode mode) { 
            CommonProperties.SetAutoSizeMode(this, mode);
        }

        protected AutoSizeMode GetAutoSizeMode() { 
            return CommonProperties.GetAutoSizeMode(this);
        } 
 
        /// 
        // Public because this is interesting for ControlDesigners. 
        [Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced)]
        public virtual LayoutEngine LayoutEngine {
            [System.Runtime.TargetedPatchingOptOutAttribute("Performance critical to inline across NGen image boundaries")]
            get { return DefaultLayout.Instance; } 
        }
 
        ///  
        ///     The GDI brush for our background color.
        ///     Whidbey Note: Made this internal, since we need to use this in ButtonStandardAdapter. Also, renamed 
        ///                   from BackBrush to BackColorBrush due to a naming conflict with DataGrid's BackBrush.
        /// 
        internal IntPtr BackColorBrush {
            [ResourceExposure(ResourceScope.Process)] 
            [ResourceConsumption(ResourceScope.Process)]
            get { 
                object customBackBrush = Properties.GetObject(PropBackBrush); 
                if (customBackBrush != null) {
 
                    // We already have a valid brush.  Unbox, and return.
                    //
                    return (IntPtr)customBackBrush;
                } 

                if (!Properties.ContainsObject(PropBackColor)) { 
 
                    // No custom back color.  See if we can get to our parent.
                    // The color check here is to account for parents and children who 
                    // override the BackColor property.
                    //
                    if (parent != null && parent.BackColor == BackColor) {
                        return parent.BackColorBrush; 
                    }
                } 
 
                // No parent, or we have a custom back color.  Either way, we need to
                // create our own. 
                //
                Color color = BackColor;
                IntPtr backBrush;
 
                if (ColorTranslator.ToOle(color) < 0) {
                    backBrush = SafeNativeMethods.GetSysColorBrush(ColorTranslator.ToOle(color) & 0xFF); 
                    SetState(STATE_OWNCTLBRUSH, false); 
                }
                else { 
                    backBrush = SafeNativeMethods.CreateSolidBrush(ColorTranslator.ToWin32(color));
                    SetState(STATE_OWNCTLBRUSH, true);
                }
 
                Debug.Assert(backBrush != IntPtr.Zero, "Failed to create brushHandle");
                Properties.SetObject(PropBackBrush, backBrush); 
 
                return backBrush;
            } 
        }

        /// 
        ///  
        ///     The background color of this control. This is an ambient property and
        ///     will always return a non-null value. 
        ///  
        [
        SRCategory(SR.CatAppearance), 
        DispId(NativeMethods.ActiveX.DISPID_BACKCOLOR),
        SRDescription(SR.ControlBackColorDescr)
        ]
        public virtual Color BackColor { 
            get {
                Color c = RawBackColor; // inheritedProperties.BackColor 
                if (!c.IsEmpty) { 
                    return c;
                } 

                Control p = ParentInternal;
                if (p != null && p.CanAccessProperties) {
                    c = p.BackColor; 
                    if (IsValidBackColor(c))
                    { 
                        return c; 
                    }
 
                }

                if (IsActiveX) {
                    c = ActiveXAmbientBackColor; 
                }
 
                if (c.IsEmpty) { 
                    AmbientProperties ambient = AmbientPropertiesService;
                    if (ambient != null) 
                        c = ambient.BackColor;
                }

                if (!c.IsEmpty && IsValidBackColor(c)) 
                    return c;
                else 
                    return DefaultBackColor; 
            }
 
            set {
                if (!value.Equals(Color.Empty) && !GetStyle(ControlStyles.SupportsTransparentBackColor) && value.A < 255)
                    throw new ArgumentException(SR.GetString(SR.TransparentBackColorNotAllowed));
 
                Color c = BackColor;
                if (!value.IsEmpty || Properties.ContainsObject(PropBackColor)) { 
                    Properties.SetColor(PropBackColor, value); 
                }
 
                if (!c.Equals(BackColor)) {
                    OnBackColorChanged(EventArgs.Empty);
                }
            } 
        }
 
        ///  
        /// 
        ///    [To be supplied.] 
        /// 
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlOnBackColorChangedDescr)]
        public event EventHandler BackColorChanged {
            add { 
                Events.AddHandler(EventBackColor, value);
            } 
            remove { 
                Events.RemoveHandler(EventBackColor, value);
            } 
        }

        /// 
        ///  
        ///     The background image of the control.
        ///  
        [ 
        SRCategory(SR.CatAppearance),
        DefaultValue(null), 
        Localizable(true),
        SRDescription(SR.ControlBackgroundImageDescr)
        ]
        public virtual Image BackgroundImage { 
            get {
                return (Image)Properties.GetObject(PropBackgroundImage); 
            } 
            set {
                if (BackgroundImage != value) { 
                    Properties.SetObject(PropBackgroundImage, value);
                    OnBackgroundImageChanged(EventArgs.Empty);
                }
            } 
        }
 
        ///  
        /// 
        ///    [To be supplied.] 
        /// 
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlOnBackgroundImageChangedDescr)]
        public event EventHandler BackgroundImageChanged {
            add { 
                Events.AddHandler(EventBackgroundImage, value);
            } 
            remove { 
                Events.RemoveHandler(EventBackgroundImage, value);
            } 
        }

        /// 
        ///  
        ///     The BackgroundImageLayout of the control.
        ///  
        [ 
        SRCategory(SR.CatAppearance),
        DefaultValue(ImageLayout.Tile), 
        Localizable(true),
        SRDescription(SR.ControlBackgroundImageLayoutDescr)
        ]
        public virtual ImageLayout BackgroundImageLayout { 
            get {
                bool found = Properties.ContainsObject(PropBackgroundImageLayout); 
                if (!found) { 
                    return ImageLayout.Tile;
                } 
                else {
                    return ((ImageLayout)Properties.GetObject(PropBackgroundImageLayout));
               }
            } 
            set {
                if (BackgroundImageLayout != value) { 
                    //valid values are 0x0 to 0x4 
                    if (!ClientUtils.IsEnumValid(value, (int)value, (int)ImageLayout.None, (int)ImageLayout.Zoom)){
                        throw new InvalidEnumArgumentException("value", (int)value, typeof(ImageLayout)); 
                    }
                    // Check if the value is either center, strech or zoom;
                    if (value == ImageLayout.Center || value == ImageLayout.Zoom || value == ImageLayout.Stretch) {
                        SetStyle(ControlStyles.ResizeRedraw, true); 
                        // Only for images that support transparency.
                        if (ControlPaint.IsImageTransparent(BackgroundImage)) 
                        { 
                            DoubleBuffered = true;
                        } 
                    }
                    Properties.SetObject(PropBackgroundImageLayout, value);
                    OnBackgroundImageLayoutChanged(EventArgs.Empty);
                } 
            }
        } 
 
        /// 
        ///  
        ///    [To be supplied.]
        /// 
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlOnBackgroundImageLayoutChangedDescr)]
        public event EventHandler BackgroundImageLayoutChanged { 
            add {
                Events.AddHandler(EventBackgroundImageLayout, value); 
            } 
            remove {
                Events.RemoveHandler(EventBackgroundImageLayout, value); 
            }
        }

        // Set/reset by ContainerControl.AssignActiveControlInternal 
        internal bool BecomingActiveControl
        { 
            get 
            {
                return GetState2(STATE2_BECOMINGACTIVECONTROL); 
            }
            set
            {
                if (value != this.BecomingActiveControl) 
                {
                    Application.ThreadContext.FromCurrent().ActivatingControl = (value) ? this : null; 
                    SetState2(STATE2_BECOMINGACTIVECONTROL, value); 
                }
            } 
        }

        private bool ShouldSerializeAccessibleName() {
            string accName = this.AccessibleName; 
            return accName != null && accName.Length > 0;
        } 
 
        /// 
        ///  
        ///    [To be supplied.]
        /// 
        [EditorBrowsable(EditorBrowsableState.Never)]
        public void ResetBindings() { 
            ControlBindingsCollection bindings = (ControlBindingsCollection)Properties.GetObject(PropBindings);
            if (bindings != null) { 
                bindings.Clear(); 
            }
        } 

        /// 
        /// 
        ///    BindingContextInternal provides a mechanism so that controls like SplitContainer that inherit from the 
        ///    ContainerControl can bypass the "containerControls" bindingContext property and do what the other simple controls
        ///    do. 
        ///  
        internal BindingContext BindingContextInternal
        { 
            get
            {
                // See if we have locally overridden the binding manager.
                // 
                BindingContext context = (BindingContext) Properties.GetObject(PropBindingManager);
                if (context != null) { 
                    return context; 
                }
 
                // Otherwise, see if the parent has one for us.
                //
                Control p = ParentInternal;
                if (p != null && p.CanAccessProperties) { 
                    return p.BindingContext;
                } 
 
                // Otherwise, we have no binding manager available.
                // 
                return null;
            }
            set
            { 
                BindingContext oldContext = (BindingContext) Properties.GetObject(PropBindingManager);
                BindingContext newContext = value; 
 
                if (oldContext != newContext) {
                    Properties.SetObject(PropBindingManager, newContext); 

                    // the property change will wire up the bindings.
                    //
                    OnBindingContextChanged(EventArgs.Empty); 
                }
            } 
        } 

        ///  
        /// 
        ///    [To be supplied.]
        /// 
        [ 
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden), 
        SRDescription(SR.ControlBindingContextDescr) 
        ]
        public virtual BindingContext BindingContext { 
            get {
                return BindingContextInternal;
            }
            set { 
                BindingContextInternal = value;
            } 
        } 

        ///  
        /// 
        ///    [To be supplied.]
        /// 
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlOnBindingContextChangedDescr)] 
        public event EventHandler BindingContextChanged {
            add { 
                Events.AddHandler(EventBindingContext, value); 
            }
            remove { 
                Events.RemoveHandler(EventBindingContext, value);
            }
        }
 
        /// 
        ///  
        ///    The bottom coordinate of this control. 
        /// 
        [ 
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        SRDescription(SR.ControlBottomDescr),
        SRCategory(SR.CatLayout) 
        ]
        public int Bottom { 
            get { 
                return y + height;
            } 
        }

        /// 
        ///  
        ///     The bounds of this control. This is the window coordinates of the
        ///     control in parent client coordinates. 
        ///  
        [
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        SRDescription(SR.ControlBoundsDescr),
        SRCategory(SR.CatLayout)
        ] 
        public Rectangle Bounds {
            get { 
                return new Rectangle(x, y, width, height); 
            }
 
            set {
                SetBounds(value.X, value.Y, value.Width, value.Height, BoundsSpecified.All);
            }
        } 

        ///  
        ///  
        /// 
        internal virtual bool CanAccessProperties { 
            get {
                return true;
            }
        } 

        ///  
        ///  
        ///    Indicates whether the control can receive focus. This
        ///       property is read-only. 
        /// 
        [
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden), 
        SRCategory(SR.CatFocus),
        SRDescription(SR.ControlCanFocusDescr) 
        ] 
        public bool CanFocus {
            get { 
                if (!IsHandleCreated) {
                    return false;
                }
                bool visible = SafeNativeMethods.IsWindowVisible(new HandleRef(window, Handle)); 
                bool enabled = SafeNativeMethods.IsWindowEnabled(new HandleRef(window, Handle));
                return (visible && enabled); 
            } 
        }
 
        /// 
        /// 
        ///     Determines if events can be fired on the control.  If this control is being
        ///     hosted as an ActiveX control, this property will return false if the ActiveX 
        ///     control has its events frozen.
        ///  
        protected override bool CanRaiseEvents { 
            [System.Runtime.TargetedPatchingOptOutAttribute("Performance critical to inline across NGen image boundaries")]
            get { 
                if (IsActiveX) {
                    return !ActiveXEventsFrozen;
                }
 
                return true;
            } 
        } 

        ///  
        /// 
        ///    
        ///       Indicates whether the control can be selected. This property
        ///       is read-only. 
        /// 
        [ 
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        SRCategory(SR.CatFocus), 
        SRDescription(SR.ControlCanSelectDescr)
        ]
        public bool CanSelect {
            // We implement this to allow only AxHost to override canSelectCore, but still 
            // expose the method publicly
            // 
            get { 
                return CanSelectCore();
            } 
        }

        /// 
        ///  
        ///     Indicates whether the control has captured the mouse.
        ///  
        [ 
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden), 
        SRCategory(SR.CatFocus),
        SRDescription(SR.ControlCaptureDescr)
        ]
        public bool Capture { 
            [System.Runtime.TargetedPatchingOptOutAttribute("Performance critical to inline across NGen image boundaries")]
            get { 
                return CaptureInternal; 
            }
 
            set {
                if (value) {
                    Debug.WriteLineIf(IntSecurity.SecurityDemand.TraceVerbose, "GetCapture Demanded");
                    IntSecurity.GetCapture.Demand(); 
                }
                CaptureInternal = value; 
            } 
        }
 
        // SECURITY WARNING: This property bypasses a security demand. Use with caution!
        internal bool CaptureInternal {
            [System.Runtime.TargetedPatchingOptOutAttribute("Performance critical to inline across NGen image boundaries")]
            get { 
                return IsHandleCreated && UnsafeNativeMethods.GetCapture() == Handle;
            } 
            set { 
                if (CaptureInternal != value) {
                    if (value) { 
                        UnsafeNativeMethods.SetCapture(new HandleRef(this, Handle));
                    }
                    else {
                        SafeNativeMethods.ReleaseCapture(); 
                    }
                } 
            } 
        }
 
        /// 
        /// 
        ///    
        ///       Indicates whether entering the control causes validation on the controls requiring validation. 
        /// 
        [ 
        SRCategory(SR.CatFocus), 
        DefaultValue(true),
        SRDescription(SR.ControlCausesValidationDescr) 
        ]
        public bool CausesValidation {
            get {
                return GetState(STATE_CAUSESVALIDATION); 
            }
            set { 
                if (value != this.CausesValidation) { 
                    SetState(STATE_CAUSESVALIDATION, value);
                    OnCausesValidationChanged(EventArgs.Empty); 
                }
            }
        }
 

        ///  
        ///  
        ///    [To be supplied.]
        ///  
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlOnCausesValidationChangedDescr)]
        public event EventHandler CausesValidationChanged {
            add {
                Events.AddHandler(EventCausesValidation, value); 
            }
            remove { 
                Events.RemoveHandler(EventCausesValidation, value); 
            }
        } 


        /// This is for perf. Turn this property on to temporarily enable text caching.  This is good for
        /// operations such as layout or painting where we don't expect the text to change (we will update the 
        /// cache if it does) but prevents us from sending a ton of messages turing layout.  See the PaintWithErrorHandling
        /// function. 
        /// 
        internal bool CacheTextInternal {
            get { 

                // check if we're caching text.
                //
                bool found; 
                int cacheTextCounter = Properties.GetInteger(PropCacheTextCount, out found);
 
                return cacheTextCounter > 0 || GetStyle(ControlStyles.CacheText); 
            }
            set { 

                // if this control always cachest text or the handle hasn't been created,
                // just bail.
                // 
                if (GetStyle(ControlStyles.CacheText) || !IsHandleCreated) {
                    return; 
                } 

                // otherwise, get the state and update the cache if necessary. 
                //
                bool found;
                int cacheTextCounter = Properties.GetInteger(PropCacheTextCount, out found);
 
                if (value) {
                    if (cacheTextCounter == 0) { 
                        Properties.SetObject(PropCacheTextField, text); 
                        if (text == null)  {
                            text = WindowText; 
                        }
                    }
                    cacheTextCounter++;
                } 
                else {
                    cacheTextCounter--; 
                    if (cacheTextCounter == 0) { 
                        text = (string)Properties.GetObject(PropCacheTextField, out found);
                    } 
                }
                Properties.SetInteger(PropCacheTextCount, cacheTextCounter);
            }
        } 

 
        ///  
        [ Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced),
          SRDescription(SR.ControlCheckForIllegalCrossThreadCalls), 
          DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        ]
        public static bool CheckForIllegalCrossThreadCalls {
            get { return checkForIllegalCrossThreadCalls; } 
            set { checkForIllegalCrossThreadCalls = value; }
        } 
 
        /// 
        ///  
        ///     The client rect of the control.
        /// 
        [
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        SRCategory(SR.CatLayout), 
        SRDescription(SR.ControlClientRectangleDescr) 
        ]
        public Rectangle ClientRectangle { 
            get {
                return new Rectangle(0, 0, clientWidth, clientHeight);
            }
        } 

        ///  
        ///  
        ///     The size of the clientRect.
        ///  
        [
        SRCategory(SR.CatLayout),
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden), 
        SRDescription(SR.ControlClientSizeDescr)
        ] 
        public Size ClientSize { 
            get {
                return new Size(clientWidth, clientHeight); 
            }

            set {
                SetClientSizeCore(value.Width, value.Height); 
            }
        } 
 
        /// 
        ///  
        ///    Fired when ClientSize changes.
        /// 
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlOnClientSizeChangedDescr)]
        public event EventHandler ClientSizeChanged { 
            add {
                Events.AddHandler(EventClientSize, value); 
            } 
            remove {
                Events.RemoveHandler(EventClientSize, value); 
            }
        }

        ///  
        /// 
        ///     Retrieves the company name of this specific component. 
        ///  
        [
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        DescriptionAttribute(SR.ControlCompanyNameDescr)
        ]
        public string CompanyName { 
            [ResourceExposure(ResourceScope.Machine)]
            [ResourceConsumption(ResourceScope.Machine)] 
            get { 
                return VersionInfo.CompanyName;
            } 
        }

        /// 
        ///  
        ///    Indicates whether the control or one of its children currently has the system
        ///       focus. This property is read-only. 
        ///  
        [
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        SRDescription(SR.ControlContainsFocusDescr)
        ]
        public bool ContainsFocus { 
            get {
                if (!IsHandleCreated) { 
                    return false; 
                }
 
                IntPtr focusHwnd = UnsafeNativeMethods.GetFocus();

                if (focusHwnd == IntPtr.Zero) {
                    return false; 
                }
 
                if (focusHwnd == this.Handle) { 
                    return true;
                } 

                if (UnsafeNativeMethods.IsChild(new HandleRef(this, this.Handle), new HandleRef(this, focusHwnd))) {
                    return true;
                } 

                return false; 
            } 
        }
 
        /// 
        /// 
        ///     The contextMenu associated with this control. The contextMenu
        ///     will be shown when the user right clicks the mouse on the control. 
        ///
        ///     Whidbey: ContextMenu is browsable false.  In all cases where both a context menu 
        ///     and a context menu strip are assigned, context menu will be shown instead of context menu strip. 
        /// 
        [ 
        SRCategory(SR.CatBehavior),
        DefaultValue(null),
        SRDescription(SR.ControlContextMenuDescr),
        Browsable(false) 
        ]
        public virtual ContextMenu ContextMenu { 
            get { 
                return (ContextMenu)Properties.GetObject(PropContextMenu);
            } 
            set {
                ContextMenu oldValue = (ContextMenu)Properties.GetObject(PropContextMenu);

                if (oldValue != value) { 
                    EventHandler disposedHandler = new EventHandler(DetachContextMenu);
 
                    if (oldValue != null) { 
                        oldValue.Disposed -= disposedHandler;
                    } 

                    Properties.SetObject(PropContextMenu, value);

                    if (value != null) { 
                        value.Disposed += disposedHandler;
                    } 
 
                    OnContextMenuChanged(EventArgs.Empty);
                } 
            }
        }

        ///  
        /// 
        ///    [To be supplied.] 
        ///  
        [
        SRCategory(SR.CatPropertyChanged), 
        SRDescription(SR.ControlOnContextMenuChangedDescr),
        Browsable(false)
        ]
        public event EventHandler ContextMenuChanged { 
            add {
                Events.AddHandler(EventContextMenu, value); 
            } 
            remove {
                Events.RemoveHandler(EventContextMenu, value); 
            }
        }

 
       /// 
       ///  
       ///     The contextMenuStrip associated with this control. The contextMenuStrip 
       ///     will be shown when the user right clicks the mouse on the control.
       ///     Note: if a context menu is also assigned, it will take precidence over this property. 
       /// 
        [
        SRCategory(SR.CatBehavior),
        DefaultValue(null), 
        SRDescription(SR.ControlContextMenuDescr)
        ] 
        public virtual ContextMenuStrip ContextMenuStrip { 
            get {
                 return (ContextMenuStrip)Properties.GetObject(PropContextMenuStrip); 
             }
             set {
                 ContextMenuStrip oldValue = Properties.GetObject(PropContextMenuStrip) as ContextMenuStrip;
 
                 if (oldValue != value) {
                     EventHandler disposedHandler = new EventHandler(DetachContextMenuStrip); 
 
                     if (oldValue != null) {
                         oldValue.Disposed -= disposedHandler; 
                     }

                     Properties.SetObject(PropContextMenuStrip, value);
 
                     if (value != null) {
                         value.Disposed += disposedHandler; 
                     } 

                     OnContextMenuStripChanged(EventArgs.Empty); 
                 }
             }

        } 
        /// 
        ///  
        ///    [To be supplied.] 
        /// 
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlContextMenuStripChangedDescr)] 
        public event EventHandler ContextMenuStripChanged {
            add {
                Events.AddHandler(EventContextMenuStrip, value);
            } 
            remove {
                Events.RemoveHandler(EventContextMenuStrip, value); 
            } 
        }
 
        /// 
        /// 
        ///     Collection of child controls.
        ///  
        [
        Browsable(false), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Content), 
        SRDescription(SR.ControlControlsDescr)
        ] 
        public ControlCollection Controls {
            get {
                ControlCollection controlsCollection = (ControlCollection)Properties.GetObject(PropControlsCollection);
 
                if (controlsCollection == null) {
                    controlsCollection = CreateControlsInstance(); 
                    Properties.SetObject(PropControlsCollection, controlsCollection); 
                }
                return controlsCollection; 
            }
        }

        ///  
        /// 
        ///    Indicates whether the control has been created. This property is read-only. 
        ///  
        [
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        SRDescription(SR.ControlCreatedDescr)
        ]
        public bool Created { 
            get {
                return(state & STATE_CREATED) != 0; 
            } 
        }
 
        /// 
        /// 
        ///     Returns the CreateParams used to create the handle for this control.
        ///     Inheriting classes should call base.CreateParams in the manor 
        ///     below:
        ///  
        protected virtual CreateParams CreateParams { 
            [
                SecurityPermission(SecurityAction.InheritanceDemand, Flags=SecurityPermissionFlag.UnmanagedCode), 
                SecurityPermission(SecurityAction.LinkDemand, Flags=SecurityPermissionFlag.UnmanagedCode)
            ]
            get {
 
                // CLR4.0 or later, comctl32.dll needs to be loaded explicitly.
                if (UnsafeNativeMethods.GetModuleHandle(ExternDll.Comctl32) == IntPtr.Zero) { 
                    if (UnsafeNativeMethods.LoadLibrary(ExternDll.Comctl32) == IntPtr.Zero) { 
                        int lastWin32Error = Marshal.GetLastWin32Error();
                        throw new Win32Exception(lastWin32Error, SR.GetString(SR.LoadDLLError, ExternDll.Comctl32)); 
                    }
                }

                // In a typical control this is accessed ten times to create and show a control. 
                // It is a net memory savings, then, to maintain a copy on control.
                // 
                if (createParams == null) { 
                    createParams = new CreateParams();
                } 

                CreateParams cp = createParams;
                cp.Style = 0;
                cp.ExStyle = 0; 
                cp.ClassStyle = 0;
                cp.Caption = text; 
 
                cp.X = x;
                cp.Y = y; 
                cp.Width = width;
                cp.Height = height;

                cp.Style = NativeMethods.WS_CLIPCHILDREN; 
                if (GetStyle(ControlStyles.ContainerControl)) {
                    cp.ExStyle |= NativeMethods.WS_EX_CONTROLPARENT; 
                } 
                cp.ClassStyle = NativeMethods.CS_DBLCLKS;
 
                if ((state & STATE_TOPLEVEL) == 0) {
                    // When the window is actually created, we will parent WS_CHILD windows to the
                    // parking form if cp.parent == 0.
                    // 
                    cp.Parent = parent == null ? IntPtr.Zero : parent.InternalHandle;
                    cp.Style |= NativeMethods.WS_CHILD | NativeMethods.WS_CLIPSIBLINGS; 
                } 
                else {
                    cp.Parent = IntPtr.Zero; 
                }

                if ((state & STATE_TABSTOP) != 0) cp.Style |= NativeMethods.WS_TABSTOP;
                if ((state & STATE_VISIBLE) != 0) cp.Style |= NativeMethods.WS_VISIBLE; 

                // Unlike Visible, Windows doesn't correctly inherit disabledness from its parent -- an enabled child 
                // of a disabled parent will look enabled but not get mouse events 
                if (!Enabled) cp.Style |= NativeMethods.WS_DISABLED;
 
                // If we are being hosted as an Ax control, try to prevent the parking window
                // from being created by pre-filling the window handle here.
                //
                if (cp.Parent == IntPtr.Zero && IsActiveX) { 
                    cp.Parent = ActiveXHWNDParent;
                } 
 
                // Set Rtl bits
                if (RightToLeft == RightToLeft.Yes) { 
                    cp.ExStyle |= NativeMethods.WS_EX_RTLREADING;
                    cp.ExStyle |= NativeMethods.WS_EX_RIGHT;
                    cp.ExStyle |= NativeMethods.WS_EX_LEFTSCROLLBAR;
                } 

                return cp; 
            } 
        }
 
        internal virtual void NotifyValidationResult(object sender, CancelEventArgs ev) {
            this.ValidationCancelled = ev.Cancel ;
        }
 
        /// 
        ///     Helper method... 
        /// 
        ///     Triggers validation on the active control, and returns bool indicating whether that control was valid.
        /// 
        ///     The correct way to do this is to find the common ancestor of the active control and this control,
        ///     then request validation to be performed by that common container control.
        ///
        ///     Used by controls that don't participate in the normal enter/leave/validation process, but which 
        ///     want to force form-level validation to occur before they attempt some important action.
        ///  
        internal bool ValidateActiveControl(out bool validatedControlAllowsFocusChange) { 
            bool valid = true;
            validatedControlAllowsFocusChange = false; 
            IContainerControl c = GetContainerControlInternal();
            if (c != null) {
                ContainerControl container = c as ContainerControl;
                if (container != null) { 
                    while (container.ActiveControl == null) {
                        ContainerControl cc; 
                        Control parent = container.ParentInternal; 
                        if (parent != null) {
                            cc = parent.GetContainerControlInternal() as ContainerControl; 
                            if (cc != null) {
                                container = cc;
                            }
                            else { 
                                break;
                            } 
                        } 
                        else {
                            break; 
                        }
                    }

                    valid = container.ValidateInternal(true, out validatedControlAllowsFocusChange); 
                }
            } 
 
            return valid;
        } 

        internal bool ValidationCancelled {
            set {
                SetState(STATE_VALIDATIONCANCELLED, value); 
            }
            get { 
                if (GetState(STATE_VALIDATIONCANCELLED)) { 
                    return true;
                } 
                else {
                    Control parent = this.ParentInternal;
                    if (parent != null) {
                        return parent.ValidationCancelled; 
                    }
 
                    return false; 
                }
            } 
        }

        /// 
        ///     Retrieves the Win32 thread ID of the thread that created the 
        ///     handle for this control.  If the control's handle hasn't been
        ///     created yet, this method will return the current thread's ID. 
        ///  
        /// 
        internal int CreateThreadId { 
            [ResourceExposure(ResourceScope.Process)]
            [ResourceConsumption(ResourceScope.Process)]
            get {
                if (IsHandleCreated) { 
                    int pid;
                    return SafeNativeMethods.GetWindowThreadProcessId(new HandleRef(this, Handle), out pid); 
                } 
                else {
                    return SafeNativeMethods.GetCurrentThreadId(); 
                }
            }
        }
 
        /// 
        ///  
        ///     Retrieves the cursor that will be displayed when the mouse is over this 
        ///     control.
        ///  
        [
        SRCategory(SR.CatAppearance),
        SRDescription(SR.ControlCursorDescr),
        AmbientValue(null) 
        ]
        public virtual Cursor Cursor { 
            get { 
                if (GetState(STATE_USEWAITCURSOR))
                { 
                    return Cursors.WaitCursor;
                }

                Cursor cursor = (Cursor)Properties.GetObject(PropCursor); 
                if (cursor != null) {
                    return cursor; 
                } 

                // We only do ambients for things with "Cursors.Default" 
                // as their default.
                //
                Cursor localDefault = DefaultCursor;
                if (localDefault != Cursors.Default) { 
                    return localDefault;
                } 
 
                Control p = ParentInternal;
                if (p != null) { 
                    return p.Cursor;
                }

                AmbientProperties ambient = AmbientPropertiesService; 
                if (ambient != null && ambient.Cursor != null)
                    return ambient.Cursor; 
 
                return localDefault;
            } 
            set {

                Cursor localCursor = (Cursor)Properties.GetObject(PropCursor);
                Cursor resolvedCursor = Cursor; 
                if (localCursor != value) {
                    Debug.WriteLineIf(IntSecurity.SecurityDemand.TraceVerbose, "ModifyCursor Demanded"); 
                    IntSecurity.ModifyCursor.Demand(); 

                    Properties.SetObject(PropCursor, value); 
                }

                // Other things can change the cursor... we
                // really want to force the correct cursor always... 
                //
                if (IsHandleCreated) { 
                    // We want to instantly change the cursor if the mouse is within our bounds. 
                    // This includes the case where the mouse is over one of our children
                    NativeMethods.POINT p = new NativeMethods.POINT(); 
                    NativeMethods.RECT r = new NativeMethods.RECT();
                    UnsafeNativeMethods.GetCursorPos(p);
                    UnsafeNativeMethods.GetWindowRect(new HandleRef(this, Handle), ref r);
 
                    if ((r.left <= p.x && p.x < r.right && r.top <= p.y && p.y < r.bottom) || UnsafeNativeMethods.GetCapture() == Handle)
                        SendMessage(NativeMethods.WM_SETCURSOR, Handle, (IntPtr)NativeMethods.HTCLIENT); 
                } 

                if (!resolvedCursor.Equals(value)) { 
                    OnCursorChanged(EventArgs.Empty);
                }
            }
        } 

        ///  
        ///  
        ///    [To be supplied.]
        ///  
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlOnCursorChangedDescr)]
        public event EventHandler CursorChanged {
            add {
                Events.AddHandler(EventCursor, value); 
            }
            remove { 
                Events.RemoveHandler(EventCursor, value); 
            }
        } 

        /// 
        /// 
        ///     Retrieves the bindings for this control. 
        /// 
        [ 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Content), 
        SRCategory(SR.CatData),
        SRDescription(SR.ControlBindingsDescr), 
        RefreshProperties(RefreshProperties.All),
        ParenthesizePropertyName(true)
        ]
        public ControlBindingsCollection DataBindings 
        {
            get 
            { 
                ControlBindingsCollection bindings = (ControlBindingsCollection)Properties.GetObject(PropBindings);
                if (bindings == null) 
                {
                    bindings = new ControlBindingsCollection(this);
                    Properties.SetObject(PropBindings, bindings);
                } 
                return bindings;
            } 
        } 

        ///  
        /// 
        ///     The default BackColor of a generic top-level Control.  Subclasses may have
        ///     different defaults.
        ///  
        public static Color DefaultBackColor {
            get { return SystemColors.Control;} 
        } 

        ///  
        /// 
        ///     Deriving classes can override this to configure a default cursor for their control.
        ///     This is more efficient than setting the cursor in the control's constructor,
        ///     and gives automatic support for ShouldSerialize and Reset in the designer. 
        /// 
        protected virtual Cursor DefaultCursor { 
            get { 
                return Cursors.Default;
            } 
        }

        /// 
        ///  
        ///     The default Font of a generic top-level Control.  Subclasses may have
        ///     different defaults. 
        ///  
        public static Font DefaultFont {
            [ResourceExposure(ResourceScope.None)] 
            [ResourceConsumption(ResourceScope.Process, ResourceScope.Process)]
            get {
                if (defaultFont == null) {
                    defaultFont = SystemFonts.DefaultFont; 
                    Debug.Assert(defaultFont != null, "defaultFont wasn't set!");
                } 
 
                return defaultFont;
            } 
        }

        /// 
        ///  
        ///     The default ForeColor of a generic top-level Control.  Subclasses may have
        ///     different defaults. 
        ///  
        public static Color DefaultForeColor {
            get { return SystemColors.ControlText;} 
        }

        /// 
        protected virtual Padding DefaultMargin { 
            get { return CommonProperties.DefaultMargin; }
        } 
 
        /// 
        protected virtual Size DefaultMaximumSize { 
            get { return CommonProperties.DefaultMaximumSize; }
        }

        ///  
        protected virtual Size DefaultMinimumSize {
            get { return CommonProperties.DefaultMinimumSize; } 
        } 

        ///  
        protected virtual Padding DefaultPadding {
            get { return Padding.Empty; }
        }
 
        private RightToLeft DefaultRightToLeft {
            get { return RightToLeft.No; } 
        } 

        ///  
        /// 
        ///     Deriving classes can override this to configure a default size for their control.
        ///     This is more efficient than setting the size in the control's constructor.
        ///  
        protected virtual Size DefaultSize {
            get { return Size.Empty; } 
        } 

        private void DetachContextMenu(object sender, EventArgs e) { 
            ContextMenu = null;
        }

 
        private void DetachContextMenuStrip(object sender, EventArgs e) {
            ContextMenuStrip = null; 
        } 

        // The color to use when drawing disabled text.  Normally we use BackColor, 
        // but that obviously won't work if we're transparent.
        internal Color DisabledColor {
            get {
                Color color = BackColor; 
                if (color.A == 0) {
                    Control control = ParentInternal; 
                    while (color.A == 0) { 
                        if (control == null) {
                            // Don't know what to do, this seems good as anything 
                            color = SystemColors.Control;
                            break;
                        }
                        color = control.BackColor; 
                        control = control.ParentInternal;
                    } 
                } 
                return color;
            } 
        }

        /// 
        ///  
        ///     Returns the client rect of the display area of the control.
        ///     For the base control class, this is identical to getClientRect. 
        ///     However, inheriting controls may want to change this if their client 
        ///     area differs from their display area.
        ///  
        [
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        SRDescription(SR.ControlDisplayRectangleDescr) 
        ]
        public virtual Rectangle DisplayRectangle { 
            [SuppressMessage("Microsoft.Security", "CA2119:SealMethodsThatSatisfyPrivateInterfaces")] 
            get {
                return new Rectangle(0, 0, clientWidth, clientHeight); 
            }
        }

        ///  
        /// 
        ///    Indicates whether the control has been disposed. This 
        ///       property is read-only. 
        /// 
        [ 
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        SRDescription(SR.ControlDisposedDescr)
        ] 
        public bool IsDisposed {
            get { 
                return GetState(STATE_DISPOSED); 
            }
        } 

        /// 
        ///     Disposes of the currently selected font handle (if cached).
        ///  
        private void DisposeFontHandle() {
            if (Properties.ContainsObject(PropFontHandleWrapper)) { 
                FontHandleWrapper fontHandle = Properties.GetObject(PropFontHandleWrapper) as FontHandleWrapper; 
                if( fontHandle != null ){
                    fontHandle.Dispose(); 
                }
                Properties.SetObject(PropFontHandleWrapper, null);
            }
        } 

        ///  
        ///  
        ///    Indicates whether the control is in the process of being disposed. This
        ///       property is read-only. 
        /// 
        [
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden), 
        SRDescription(SR.ControlDisposingDescr)
        ] 
        public bool Disposing { 
            get {
                return GetState(STATE_DISPOSING); 
            }
        }

        ///  
        /// 
        ///     The dock property. The dock property controls to which edge 
        ///     of the container this control is docked to. For example, when docked to 
        ///     the top of the container, the control will be displayed flush at the
        ///     top of the container, extending the length of the container. 
        /// 
        [
        SRCategory(SR.CatLayout),
        Localizable(true), 
        RefreshProperties(RefreshProperties.Repaint),
        DefaultValue(CommonProperties.DefaultDock), 
        SRDescription(SR.ControlDockDescr) 
        ]
        public virtual DockStyle Dock { 
            get {
                return DefaultLayout.GetDock(this);
            }
            set { 
                if(value != Dock) {                        // NDPWhidbey 29434
#if DEBUG 
                    int dbgLayoutCheck = LayoutSuspendCount; 
#endif
                    SuspendLayout(); 
                    try {
                        DefaultLayout.SetDock(this, value);
                        OnDockChanged(EventArgs.Empty);
                    } finally { 
                        ResumeLayout();
                    } 
#if DEBUG 
                    AssertLayoutSuspendCount(dbgLayoutCheck);
#endif 
                }
            }
        }
 
        /// 
        ///  
        ///    [To be supplied.] 
        /// 
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlOnDockChangedDescr)] 
        public event EventHandler DockChanged {
            add {
                Events.AddHandler(EventDock, value);
            } 
            remove {
                Events.RemoveHandler(EventDock, value); 
            } 
        }
 
        /// 
        /// 
        ///    This will enable or disable double buffering.
        ///  
        [
        SRCategory(SR.CatBehavior), 
        SRDescription(SR.ControlDoubleBufferedDescr) 
        ]
        protected virtual bool DoubleBuffered { 
            get {
                return GetStyle(ControlStyles.OptimizedDoubleBuffer);
            }
            set { 
                if (value != DoubleBuffered) {
 
                    if (value) { 
                        SetStyle(ControlStyles.OptimizedDoubleBuffer | ControlStyles.AllPaintingInWmPaint, value);
                    } 
                    else {
                        SetStyle(ControlStyles.OptimizedDoubleBuffer, value);
                    }
                } 
            }
        } 
 
        private bool DoubleBufferingEnabled {
            get { 
#pragma warning disable 618
                return GetStyle(ControlStyles.DoubleBuffer | ControlStyles.UserPaint);
#pragma warning restore 618
            } 
        }
 
        ///  
        /// 
        ///    Indicates whether the control is currently enabled. 
        /// 
        [
        SRCategory(SR.CatBehavior),
        Localizable(true), 
        DispId(NativeMethods.ActiveX.DISPID_ENABLED),
        SRDescription(SR.ControlEnabledDescr) 
        ] 
        public bool Enabled {
            get { 
                // We are only enabled if our parent is enabled
                if (!GetState(STATE_ENABLED))
                    return false;
                else if (ParentInternal == null) 
                    return true;
                else 
                    return ParentInternal.Enabled; 
            }
 
            set {
                bool oldValue = Enabled;
                SetState(STATE_ENABLED, value);
 
                if (oldValue != value) {
                    if (!value) { 
                        SelectNextIfFocused(); 
                    }
 
                    OnEnabledChanged(EventArgs.Empty);
                }
            }
        } 

 
        ///  
        /// 
        ///    Occurs when the control is enabled. 
        /// 
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlOnEnabledChangedDescr)]
        public event EventHandler EnabledChanged {
            add { 
                Events.AddHandler(EventEnabled, value);
            } 
            remove { 
                Events.RemoveHandler(EventEnabled, value);
            } 
        }

        /// 
        ///  
        ///    Indicates whether the control has focus. This property is read-only.
        ///  
        [ 
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden), 
        SRDescription(SR.ControlFocusedDescr)
        ]
        public virtual bool Focused {
            get { 
                return IsHandleCreated && UnsafeNativeMethods.GetFocus() == Handle;
            } 
        } 

        ///  
        /// 
        ///     Retrieves the current font for this control. This will be the font used
        ///     by default for painting and text in the control.
        ///  
        [
        SRCategory(SR.CatAppearance), 
        Localizable(true), 
        DispId(NativeMethods.ActiveX.DISPID_FONT),
        AmbientValue(null), 
        SRDescription(SR.ControlFontDescr)
        ]
        public virtual Font Font {
            [return : MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef=typeof(ActiveXFontMarshaler))] 
            [ResourceExposure(ResourceScope.None)]
            [ResourceConsumption(ResourceScope.Process, ResourceScope.Process)] 
            get { 
                Font font = (Font)Properties.GetObject(PropFont);
                if (font != null) { 
                    return font;
                }

                Font f = GetParentFont(); 
                if (f != null) {
                    return f; 
                } 

                if (IsActiveX) { 
                    f = ActiveXAmbientFont;
                    if (f != null) {
                        return f;
                    } 
                }
 
                AmbientProperties ambient = AmbientPropertiesService; 
                if (ambient != null && ambient.Font != null) {
                    return ambient.Font; 
                }

                return DefaultFont;
            } 
            [param : MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef=typeof(ActiveXFontMarshaler))]
            set { 
                Font local = (Font)Properties.GetObject(PropFont); 
                Font resolved = Font;
 
                bool localChanged = false;
                if (value == null) {
                    if (local != null) {
                        localChanged = true; 
                    }
                } 
                else { 
                    if (local == null) {
                        localChanged = true; 
                    }
                    else {
                        localChanged = !value.Equals(local);
                    } 
                }
 
                if (localChanged) { 
                    // Store new local value
                    // 
                    Properties.SetObject(PropFont, value);

                    // We only fire the Changed event if the "resolved" value
                    // changed, however we must update the font if the local 
                    // value changed...
                    // 
                    if (!resolved.Equals(value)) { 
                        // Cleanup any font handle wrapper...
                        // 
                        DisposeFontHandle();

                        if (Properties.ContainsInteger(PropFontHeight)) {
                            Properties.SetInteger(PropFontHeight, (value == null) ? -1 : value.Height); 
                        }
 
                        // Font is an ambient property.  We need to layout our parent because Font may 
                        // change our size.  We need to layout ourselves because our children may change
                        // size by inheriting the new value. 
                        //
                        using(new LayoutTransaction(ParentInternal, this, PropertyNames.Font)) {
                            OnFontChanged(EventArgs.Empty);
                        } 
                    }
                    else { 
                        if (IsHandleCreated && !GetStyle(ControlStyles.UserPaint)) { 
                            DisposeFontHandle();
                            SetWindowFont(); 
                        }
                    }
                }
            } 
        }
 
        ///  
        /// 
        ///    [To be supplied.] 
        /// 
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlOnFontChangedDescr)]
        public event EventHandler FontChanged {
            add { 
                Events.AddHandler(EventFont, value);
            } 
            remove { 
                Events.RemoveHandler(EventFont, value);
            } 
        }

        internal IntPtr FontHandle {
            get { 
                Font font = (Font)Properties.GetObject(PropFont);
 
                if (font != null) { 
                    FontHandleWrapper fontHandle = (FontHandleWrapper)Properties.GetObject(PropFontHandleWrapper);
                    if (fontHandle == null) { 
                        fontHandle = new FontHandleWrapper(font);

                        Properties.SetObject(PropFontHandleWrapper, fontHandle);
                    } 

                    return fontHandle.Handle; 
                } 

                if (parent != null) { 
                    return parent.FontHandle;
                }

                AmbientProperties ambient = AmbientPropertiesService; 

                if (ambient != null && ambient.Font != null) { 
 
                    FontHandleWrapper fontHandle = null;
 
                    Font currentAmbient = (Font)Properties.GetObject(PropCurrentAmbientFont);

                    if (currentAmbient != null && currentAmbient == ambient.Font) {
                        fontHandle = (FontHandleWrapper)Properties.GetObject(PropFontHandleWrapper); 
                    }
                    else { 
                        Properties.SetObject(PropCurrentAmbientFont, ambient.Font); 
                    }
 
                    if (fontHandle == null) {
                        font =  ambient.Font;
                        fontHandle = new FontHandleWrapper(font);
 
                        Properties.SetObject(PropFontHandleWrapper, fontHandle);
                    } 
 
                    return fontHandle.Handle;
                } 

                return GetDefaultFontHandleWrapper().Handle;
            }
        } 

        ///  
        ///  
        ///    [To be supplied.]
        ///  
        protected int FontHeight {
            get {
                bool found;
                int fontHeight = Properties.GetInteger(PropFontHeight, out found); 
                if (found && fontHeight != -1) {
                    return fontHeight; 
                } 
                else {
                    Font font = (Font)Properties.GetObject(PropFont); 
                    if (font != null) {
                        fontHeight = font.Height;
                        Properties.SetInteger(PropFontHeight, fontHeight);
                        return fontHeight; 
                    }
                } 
 
                //ask the parent if it has the font height
                int localFontHeight = -1; 

                if (ParentInternal != null && ParentInternal.CanAccessProperties) {
                    localFontHeight = ParentInternal.FontHeight;
                } 

                //if we still have a bad value, then get the actual font height 
                if (localFontHeight == -1) { 
                    localFontHeight = Font.Height;
                    Properties.SetInteger(PropFontHeight, localFontHeight); 
                }

                return localFontHeight;
            } 
            set {
                Properties.SetInteger(PropFontHeight, value); 
            } 
        }
 
        /// 
        /// 
        ///     The foreground color of the control.
        ///  
        [
        SRCategory(SR.CatAppearance), 
        DispId(NativeMethods.ActiveX.DISPID_FORECOLOR), 
        SRDescription(SR.ControlForeColorDescr)
        ] 
        public virtual Color ForeColor {
            get {
                Color color = Properties.GetColor(PropForeColor);
                if (!color.IsEmpty) { 
                    return color;
                } 
 
                Control p = ParentInternal;
                if (p != null && p.CanAccessProperties) { 
                    return p.ForeColor;
                }

                Color c = Color.Empty; 

                if (IsActiveX) { 
                    c = ActiveXAmbientForeColor; 
                }
 
                if (c.IsEmpty) {
                    AmbientProperties ambient = AmbientPropertiesService;
                    if (ambient != null)
                        c = ambient.ForeColor; 
                }
 
                if (!c.IsEmpty) 
                    return c;
                else 
                    return DefaultForeColor;
            }

            set { 
                Color c = ForeColor;
                if (!value.IsEmpty || Properties.ContainsObject(PropForeColor)) { 
                    Properties.SetColor(PropForeColor, value); 
                }
                if (!c.Equals(ForeColor)) { 
                    OnForeColorChanged(EventArgs.Empty);
                }
            }
        } 

        ///  
        ///  
        ///    [To be supplied.]
        ///  
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlOnForeColorChangedDescr)]
        public event EventHandler ForeColorChanged {
            add {
                Events.AddHandler(EventForeColor, value); 
            }
            remove { 
                Events.RemoveHandler(EventForeColor, value); 
            }
        } 

        private Font GetParentFont() {
            if (ParentInternal != null && ParentInternal.CanAccessProperties)
                return ParentInternal.Font; 
            else
                return null; 
        } 

        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        [SuppressMessage("Microsoft.Security", "CA2119:SealMethodsThatSatisfyPrivateInterfaces")]
        public virtual Size GetPreferredSize(Size proposedSize) {
            Size prefSize; 

            if (GetState(STATE_DISPOSING| STATE_DISPOSED)) { 
                // if someone's asking when we're disposing just return what we last had. 
                prefSize = CommonProperties.xGetPreferredSizeCache(this);
            } 
            else {
                 // Switch Size.Empty to maximum possible values
                proposedSize = LayoutUtils.ConvertZeroToUnbounded(proposedSize);
 
                // Force proposedSize to be within the elements constraints.  (This applies
                // minimumSize, maximumSize, etc.) 
                proposedSize = ApplySizeConstraints(proposedSize); 
                if (GetState2(STATE2_USEPREFERREDSIZECACHE)) {
                    Size cachedSize = CommonProperties.xGetPreferredSizeCache(this); 

                    // If the "default" preferred size is being requested, and we have a cached value for it, return it.
                    //
                    if(!cachedSize.IsEmpty && (proposedSize == LayoutUtils.MaxSize)) { 

#if DEBUG 
#if DEBUG_PREFERREDSIZE 
                            Size newPreferredSize = ApplySizeConstraints(GetPreferredSizeCore(proposedSize));
                            bool cacheHitCorrect = (cachedSize == newPreferredSize); 
                            if (!cacheHitCorrect && !GetAnyDisposingInHierarchy()) {
                                Debug.Fail(
                                      "Cached PreferredSize " + cachedSize.ToString()
                                      + " did not match computed: " +newPreferredSize.ToString() 
                                      +". Did we forget to invalidate the cache?\r\n\r\nControl Information: " + WindowsFormsUtils.AssertControlInformation(cacheHitCorrect, this)
                                      + "\r\nChanged Properties\r\n " + CommonProperties.Debug_GetChangedProperties(this)); 
                            } 
#endif
#endif 
                            return cachedSize;
                    }
                }
 

 
                CacheTextInternal = true; 
                try {
                    prefSize = GetPreferredSizeCore(proposedSize); 
                }
                finally {
                    CacheTextInternal = false;
                } 

                // There is no guarantee that GetPreferredSizeCore() return something within 
                // proposedSize, so we apply the element's constraints again. 
                prefSize = ApplySizeConstraints(prefSize);
 
                // If the "default" preferred size was requested, cache the computed value.
                //
                if(GetState2(STATE2_USEPREFERREDSIZECACHE) && proposedSize == LayoutUtils.MaxSize) {
                    CommonProperties.xSetPreferredSizeCache(this, prefSize); 
                }
            } 
            return prefSize; 
        }
 
        // Overriding this method allows us to get the caching and clamping the proposedSize/output to
        // MinimumSize / MaximumSize from GetPreferredSize for free.
        internal virtual Size GetPreferredSizeCore(Size proposedSize) {
            return CommonProperties.GetSpecifiedBounds(this).Size; 
        }
 
        ///  
        /// 
        ///     The HWND handle that this control is bound to. If the handle 
        ///     has not yet been created, this will force handle creation.
        /// 
        [
        Browsable(false), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        DispId(NativeMethods.ActiveX.DISPID_HWND), 
        SRDescription(SR.ControlHandleDescr) 
        ]
        public IntPtr Handle { 
            get {
                if (checkForIllegalCrossThreadCalls &&
                    !inCrossThreadSafeCall &&
                    InvokeRequired) { 
                    throw new InvalidOperationException(SR.GetString(SR.IllegalCrossThreadCall,
                                                                     Name)); 
                } 

                if (!IsHandleCreated) 
                {
                    CreateHandle();
                }
 
                return HandleInternal;
            } 
        } 

        internal IntPtr HandleInternal { 
            get {
                return window.Handle;
            }
        } 

        ///  
        ///  
        ///     True if this control has child controls in its collection.  This
        ///     is more efficient than checking for Controls.Count > 0, but has the 
        ///     same effect.
        /// 
        [
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        SRDescription(SR.ControlHasChildrenDescr) 
        ] 
        public bool HasChildren {
            get { 
                ControlCollection controls = (ControlCollection)Properties.GetObject(PropControlsCollection);
                return controls != null && controls.Count > 0;
            }
        } 

        internal virtual bool HasMenu { 
            get { 
                return false;
            } 
        }

        /// 
        ///  
        ///     The height of this control
        ///  
        [ 
        SRCategory(SR.CatLayout),
        Browsable(false), EditorBrowsable(EditorBrowsableState.Always), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        SRDescription(SR.ControlHeightDescr)
        ]
        public int Height { 
            get {
                return height; 
            } 
            set{
                SetBounds(x, y, width, value, BoundsSpecified.Height); 
            }
        }

        internal bool HostedInWin32DialogManager { 
            get {
                if (!GetState(STATE_CHECKEDHOST)) { 
                    Control topMost = TopMostParent; 
                    if (this != topMost) {
                        SetState(STATE_HOSTEDINDIALOG, topMost.HostedInWin32DialogManager); 
                    }
                    else {
                        IntPtr parentHandle = UnsafeNativeMethods.GetParent(new HandleRef(this, Handle));
                        IntPtr lastParentHandle = parentHandle; 

                        StringBuilder sb = new StringBuilder(32); 
 
                        SetState(STATE_HOSTEDINDIALOG, false);
 
                        while (parentHandle != IntPtr.Zero) {
                            int len = UnsafeNativeMethods.GetClassName(new HandleRef(null, lastParentHandle), null, 0);
                            if (len > sb.Capacity) {
                                sb.Capacity = len + 5; 
                            }
                            UnsafeNativeMethods.GetClassName(new HandleRef(null, lastParentHandle), sb, sb.Capacity); 
 
                            if (sb.ToString() == "#32770") {
                                SetState(STATE_HOSTEDINDIALOG, true); 
                                break;
                            }

                            lastParentHandle = parentHandle; 
                            parentHandle = UnsafeNativeMethods.GetParent(new HandleRef(null, parentHandle));
                        } 
                    } 

                    SetState(STATE_CHECKEDHOST, true); 

                }

                return GetState(STATE_HOSTEDINDIALOG); 
            }
        } 
 
        /// 
        ///  
        ///     Whether or not this control has a handle associated with it.
        /// 
        [
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        SRDescription(SR.ControlHandleCreatedDescr) 
        ] 
        public bool IsHandleCreated {
            get { return window.Handle != IntPtr.Zero; } 
        }

        /// 
        ///     Determines if layout is currently suspended. 
        /// 
        internal bool IsLayoutSuspended { 
            get { 
                return layoutSuspendCount > 0;
            } 
        }

        internal bool IsWindowObscured {
            get { 
                if (!IsHandleCreated || !Visible) {
                    return false; 
                } 

                bool emptyRegion = false; 

                NativeMethods.RECT temp = new NativeMethods.RECT();
                Region working;
                Control parent = ParentInternal; 
                if (parent != null) {
                    while (parent.ParentInternal != null ) { 
                        parent = parent.ParentInternal; 
                    }
                } 

                UnsafeNativeMethods.GetWindowRect(new HandleRef(this, Handle), ref temp);
                working = new Region(Rectangle.FromLTRB(temp.left, temp.top, temp.right, temp.bottom));
 
                try {
                    IntPtr prev; 
                    IntPtr next; 
                    IntPtr start;
                    if (parent != null) { 
                        start = parent.Handle;
                    }
                    else {
                        start = Handle; 
                    }
 
                    for (prev = start; 
                         (next = UnsafeNativeMethods.GetWindow(new HandleRef(null, prev), NativeMethods.GW_HWNDPREV)) != IntPtr.Zero;
                         prev = next) { 

                        UnsafeNativeMethods.GetWindowRect(new HandleRef(null, next), ref temp);
                        Rectangle current = Rectangle.FromLTRB(temp.left, temp.top, temp.right, temp.bottom);
 
                        if (SafeNativeMethods.IsWindowVisible(new HandleRef(null, next))) {
                            working.Exclude(current); 
                        } 
                    }
 

                    Graphics g = CreateGraphics();
                    try {
                        emptyRegion = working.IsEmpty(g); 
                    }
                    finally { 
                        g.Dispose(); 
                    }
                } 
                finally {
                    working.Dispose();
                }
 
                return emptyRegion;
            } 
        } 

        ///  
        ///     Returns the current value of the handle. This may be zero if the handle
        ///     has not been created.
        /// 
        internal IntPtr InternalHandle { 
            get {
                if (!IsHandleCreated) 
                { 
                    return IntPtr.Zero;
                } 
                else
                {
                    return Handle;
                } 
            }
        } 
 
        /// 
        ///  
        ///     Determines if the caller must call invoke when making method
        ///     calls to this control.  Controls in windows forms are bound to a specific thread,
        ///     and are not thread safe.  Therefore, if you are calling a control's method
        ///     from a different thread, you must use the control's invoke method 
        ///     to marshal the call to the proper thread.  This function can be used to
        ///     determine if you must call invoke, which can be handy if you don't know 
        ///     what thread owns a control. 
        ///
        ///     There are five functions on a control that are safe to call from any 
        ///     thread:  GetInvokeRequired, Invoke, BeginInvoke, EndInvoke and
        ///     CreateGraphics.  For all other metohd calls, you should use one of the
        ///     invoke methods.
        ///  
        [
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden), 
        SRDescription(SR.ControlInvokeRequiredDescr)
        ] 
        public bool InvokeRequired {
            get {

                using (new MultithreadSafeCallScope()) 
                {
                    HandleRef hwnd; 
                    if (IsHandleCreated) { 
                        hwnd = new HandleRef(this, Handle);
                    } 
                    else {
                        Control marshalingControl = FindMarshalingControl();

                        if (!marshalingControl.IsHandleCreated) { 
                            return false;
                        } 
 
                        hwnd = new HandleRef(marshalingControl, marshalingControl.Handle);
                    } 

                    int pid;
                    int hwndThread = SafeNativeMethods.GetWindowThreadProcessId(hwnd, out pid);
                    int currentThread = SafeNativeMethods.GetCurrentThreadId(); 
                    return(hwndThread != currentThread);
                } 
            } 
        }
 
        /// 
        /// 
        ///      Indicates whether or not this control is an accessible control
        ///      i.e. whether it should be visible to accessibility applications. 
        /// 
        [ 
        SRCategory(SR.CatBehavior), 
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden), 
        SRDescription(SR.ControlIsAccessibleDescr)
        ]
        public bool IsAccessible {
            get { 
                return GetState(STATE_ISACCESSIBLE);
            } 
            set { 
                SetState(STATE_ISACCESSIBLE, value);
            } 
        }

        /// 
        ///     Used to tell if this control is being hosted as an ActiveX control. 
        /// 
        internal bool IsActiveX { 
            get { 
                return GetState2(STATE2_ISACTIVEX);
            } 
        }

        // VsWhidbey 434959 : If the control on which GetContainerControl( ) is called is a ContainerControl, then we dont return the parent
        // but return the same control. This is Everett behavior so we cannot change this since this would be a breaking change. 
        // Hence we have a new internal property IsContainerControl which returns false for all Everett control, but
        // this property is overidden in SplitContainer to return true so that we skip the SplitContainer 
        // and the correct Parent ContainerControl is returned by GetContainerControl(). 
        internal virtual bool IsContainerControl
        { 
            get
            {
                return false;
            } 
        }
 
        ///  
        ///     Used to tell if this control is being hosted in IE.
        ///  
        internal bool IsIEParent {
            get {
                return IsActiveX ? ActiveXInstance.IsIE : false;
            } 
        }
 
        ///  
        ///     Used to tell if the control is mirrored
        ///     Don't call this from CreateParams. Will lead to nasty problems 
        ///     since we might call CreateParams here - you dig!
        /// 
        [
        SRCategory(SR.CatLayout), 
        Browsable(false),
        EditorBrowsable(EditorBrowsableState.Advanced), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden), 
        SRDescription(SR.IsMirroredDescr)
        ] 
        public bool IsMirrored {
            get {
                if (!IsHandleCreated) {
                    CreateParams cp = CreateParams; 
                    SetState(STATE_MIRRORED, (cp.ExStyle & NativeMethods.WS_EX_LAYOUTRTL) != 0);
                } 
                return GetState(STATE_MIRRORED); 
            }
        } 

        /// 
        ///     Specifies whether the control is willing to process mnemonics when hosted in an container ActiveX (Ax Sourcing).
        ///  
        internal virtual bool IsMnemonicsListenerAxSourced
        { 
            get 
            {
                return false; 
            }
        }

        ///  
        ///     Used to tell if this BackColor is Supported
        ///  
        private bool IsValidBackColor (Color c){ 
           if (!c.IsEmpty && !GetStyle(ControlStyles.SupportsTransparentBackColor) && c.A < 255)
           { 
                return false;
           }
           return true;
 
        }
 
        ///  
        /// 
        ///     The left coordinate of this control. 
        /// 
        [
        SRCategory(SR.CatLayout),
        Browsable(false), EditorBrowsable(EditorBrowsableState.Always), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        SRDescription(SR.ControlLeftDescr) 
        ] 
        public int Left {
            get { 
                return x;
            }
            set {
                SetBounds(value, y, width, height, BoundsSpecified.X); 
            }
        } 
 
        /// 
        ///  
        ///     The location of this control.
        /// 
        [
        SRCategory(SR.CatLayout), 
        Localizable(true),
        SRDescription(SR.ControlLocationDescr) 
        ] 
        public Point Location {
            get { 
                return new Point(x, y);
            }
            set {
                SetBounds(value.X, value.Y, width, height, BoundsSpecified.Location); 
            }
        } 
 
        /// 
        ///  
        ///    [To be supplied.]
        /// 
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlOnLocationChangedDescr)]
        public event EventHandler LocationChanged { 
            add {
                Events.AddHandler(EventLocation, value); 
            } 
            remove {
                Events.RemoveHandler(EventLocation, value); 
            }
        }

        ///  
        [
        SRDescription(SR.ControlMarginDescr), 
        SRCategory(SR.CatLayout), 
        Localizable(true)
        ] 
        public Padding Margin
        {
            get { return CommonProperties.GetMargin(this); }
            set 
            {
                // This should be done here rather than in the property store as 
                // some IArrangedElements actually support negative padding. 
                value = LayoutUtils.ClampNegativePaddingToZero(value);
 
                // SetMargin causes a layout as a side effect.
                if (value != Margin)
                {
                    CommonProperties.SetMargin(this, value); 
                    OnMarginChanged(EventArgs.Empty);
                } 
                Debug.Assert(Margin == value, "Error detected while setting Margin."); 
            }
        } 

        /// 
        /// 
        ///    [To be supplied.] 
        /// 
        [SRCategory(SR.CatLayout), SRDescription(SR.ControlOnMarginChangedDescr)] 
        public event EventHandler MarginChanged 
        {
            add 
            {
                Events.AddHandler(EventMarginChanged, value);
            }
            remove 
            {
                Events.RemoveHandler(EventMarginChanged, value); 
            } 
        }
 
        /// 
        [SRCategory(SR.CatLayout)]
        [SRDescription(SR.ControlMaximumSizeDescr)]
        [AmbientValue(typeof(Size), "0, 0")] 
        public virtual Size MaximumSize {
            get { return CommonProperties.GetMaximumSize(this, DefaultMaximumSize); } 
            set { 
                if (value == Size.Empty) {
                    CommonProperties.ClearMaximumSize(this); 
                    Debug.Assert(MaximumSize == DefaultMaximumSize, "Error detected while resetting MaximumSize.");
                }
                else if (value != MaximumSize) {
                    // SetMaximumSize causes a layout as a side effect. 
                    CommonProperties.SetMaximumSize(this, value);
                    Debug.Assert(MaximumSize == value, "Error detected while setting MaximumSize."); 
                } 

            } 
        }

        /// 
        [SRCategory(SR.CatLayout)] 
        [SRDescription(SR.ControlMinimumSizeDescr)]
        public virtual Size MinimumSize { 
            get { return CommonProperties.GetMinimumSize(this, DefaultMinimumSize); } 
            set {
                if (value != MinimumSize) { 
                    // SetMinimumSize causes a layout as a side effect.
                    CommonProperties.SetMinimumSize(this, value);
                }
                Debug.Assert(MinimumSize == value, "Error detected while setting MinimumSize."); 
            }
        } 
 

        ///  
        /// 
        ///     Retrieves the current state of the modifier keys. This will check the
        ///     current state of the shift, control, and alt keys.
        ///  
        public static Keys ModifierKeys {
            get { 
                Keys modifiers = 0; 
                // SECURITYNOTE : only let state of Shift-Control-Alt out...
                // 
                if (UnsafeNativeMethods.GetKeyState((int)Keys.ShiftKey) < 0) modifiers |= Keys.Shift;
                if (UnsafeNativeMethods.GetKeyState((int)Keys.ControlKey) < 0) modifiers |= Keys.Control;
                if (UnsafeNativeMethods.GetKeyState((int)Keys.Menu) < 0) modifiers |= Keys.Alt;
                return modifiers; 
            }
        } 
 
        /// 
        ///  
        ///     The current state of the mouse buttons. This will check the
        ///     current state of the left, right, and middle mouse buttons.
        /// 
        public static MouseButtons MouseButtons { 
            get {
                MouseButtons buttons = (MouseButtons)0; 
                // SECURITYNOTE : only let state of MouseButtons out... 
                //
                if (UnsafeNativeMethods.GetKeyState((int)Keys.LButton) < 0) buttons |= MouseButtons.Left; 
                if (UnsafeNativeMethods.GetKeyState((int)Keys.RButton) < 0) buttons |= MouseButtons.Right;
                if (UnsafeNativeMethods.GetKeyState((int)Keys.MButton) < 0) buttons |= MouseButtons.Middle;
                if (UnsafeNativeMethods.GetKeyState((int)Keys.XButton1) < 0) buttons |= MouseButtons.XButton1;
                if (UnsafeNativeMethods.GetKeyState((int)Keys.XButton2) < 0) buttons |= MouseButtons.XButton2; 
                return buttons;
            } 
        } 

        ///  
        /// 
        ///     The current position of the mouse in screen coordinates.
        /// 
        public static Point MousePosition { 
            get {
                // Reviewed: The following demand has always been commented out since v1.0. In Whidbey, we have 
                // re-reviewed this method to see if it needs protection, but haven't found any threats, so are 
                // going to keep it this way. See VSWhidbey #427555 for details.
                // 
                // Debug.WriteLineIf(IntSecurity.SecurityDemand.TraceVerbose, "ScreenLocationOfThings Demanded");
                // IntSecurity.ScreenLocationOfThings.Demand();

                NativeMethods.POINT pt = new NativeMethods.POINT(); 
                UnsafeNativeMethods.GetCursorPos(pt);
                return new Point(pt.x, pt.y); 
            } 
        }
 
        /// 
        /// 
        ///     Name of this control. The designer will set this to the same
        ///     as the programatic Id "(name)" of the control.  The name can be 
        ///     used as a key into the ControlCollection.
        ///  
        [Browsable(false)] 
        public string Name {
            get { 
                string name = (string)Properties.GetObject(PropName);
                if (String.IsNullOrEmpty(name)) {
                    if (Site != null) {
                        name = Site.Name; 
                    }
 
                    if (name == null) { 
                        name = "";
                    } 
                }

                return name;
            } 
            set {
                if (String.IsNullOrEmpty(value)) { 
                    Properties.SetObject(PropName, null); 
                }
                else { 
                    Properties.SetObject(PropName, value);
                }
            }
        } 

        ///  
        ///  
        ///     The parent of this control.
        ///  
        [
        SRCategory(SR.CatBehavior),
        Browsable(false),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden), 
        SRDescription(SR.ControlParentDescr)
        ] 
        public Control Parent { 
            get {
                Debug.WriteLineIf(IntSecurity.SecurityDemand.TraceVerbose, "GetParent Demanded"); 
                IntSecurity.GetParent.Demand();

                return ParentInternal;
            } 
            set {
                ParentInternal = value; 
            } 
        }
 
        // SECURITY WARNING: This property bypasses a security demand. Use with caution!
        internal virtual Control ParentInternal {
            [System.Runtime.TargetedPatchingOptOutAttribute("Performance critical to inline across NGen image boundaries")]
            get { 
                return parent;
            } 
            set { 
                if (parent != value) {
                    if (value != null) { 
                        value.Controls.Add(this);
                    }
                    else {
                        parent.Controls.Remove(this); 
                    }
                } 
            } 
        }
 
        /// 
        /// 
        ///     Retrieves the product name of this specific component.
        ///  
        [
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden), 
        SRDescription(SR.ControlProductNameDescr)
        ] 
        public string ProductName {
            [ResourceExposure(ResourceScope.Machine)]
            [ResourceConsumption(ResourceScope.Machine)]
            get { 
                return VersionInfo.ProductName;
            } 
        } 

        ///  
        /// 
        ///     Retrieves the product version of this specific component.
        /// 
        [ 
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden), 
        SRDescription(SR.ControlProductVersionDescr) 
        ]
        public string ProductVersion { 
            [ResourceExposure(ResourceScope.Machine)]
            [ResourceConsumption(ResourceScope.Machine)]
            get {
                return VersionInfo.ProductVersion; 
            }
        } 
 
        /// 
        ///     Retrieves our internal property storage object. If you have a property 
        ///     whose value is not always set, you should store it in here to save
        ///     space.
        /// 
        internal PropertyStore Properties { 
            [System.Runtime.TargetedPatchingOptOutAttribute("Performance critical to inline across NGen image boundaries")]
            get { 
                return propertyStore; 
            }
        } 

        // Returns the value of the backColor field -- no asking the parent with its color is, etc.
        internal Color RawBackColor {
            get { 
                return Properties.GetColor(PropBackColor);
            } 
        } 

        ///  
        /// 
        ///    Indicates whether the control is currently recreating its handle. This
        ///       property is read-only.
        ///  
        [
        SRCategory(SR.CatBehavior), 
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        SRDescription(SR.ControlRecreatingHandleDescr) 
        ]
        public bool RecreatingHandle {
            get {
                return(state & STATE_RECREATE) != 0; 
            }
        } 
 
        internal virtual void AddReflectChild() {
        } 

        internal virtual void RemoveReflectChild() {
        }
 
        private Control ReflectParent {
            get { 
                return reflectParent; 
            }
            set { 
                if (value != null) {
                    value.AddReflectChild();
                }
 
                Control c = ReflectParent as Control;
                reflectParent = value; 
                if (c != null) { 
                    c.RemoveReflectChild();
                } 
            }
        }

        ///  
        /// 
        ///     The Region associated with this control.  (defines the 
        ///     outline/silhouette/boundary of control) 
        /// 
        [ 
        SRCategory(SR.CatLayout),
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        SRDescription(SR.ControlRegionDescr) 
        ]
        public Region Region { 
            get { 
                return (Region)Properties.GetObject(PropRegion);
            } 
            set {
                if (GetState(STATE_TOPLEVEL)) {
                    Debug.WriteLineIf(IntSecurity.SecurityDemand.TraceVerbose, "ChangeWindowRegion Demanded");
                    IntSecurity.ChangeWindowRegionForTopLevel.Demand(); 
                }
 
                Region oldRegion = Region; 
                if (oldRegion != value) {
                    Properties.SetObject(PropRegion, value); 

                    if (oldRegion != null) {
                        oldRegion.Dispose();
                    } 

                    if (IsHandleCreated) { 
                        IntPtr regionHandle = IntPtr.Zero; 

                        try { 
                            if (value != null) {
                                regionHandle = GetHRgn(value);
                            }
 
                            if (IsActiveX) {
                                regionHandle = ActiveXMergeRegion(regionHandle); 
                            } 

                            if (UnsafeNativeMethods.SetWindowRgn(new HandleRef(this, Handle), new HandleRef(this, regionHandle), SafeNativeMethods.IsWindowVisible(new HandleRef(this, Handle))) != 0) { 
                                //The Hwnd owns the region.
                                regionHandle = IntPtr.Zero;
                            }
                        } 
                        finally {
                            if (regionHandle != IntPtr.Zero) { 
                                SafeNativeMethods.DeleteObject(new HandleRef(null, regionHandle)); 
                            }
                        } 
                    }

                    OnRegionChanged(EventArgs.Empty);
                } 
            }
        } 
 
        /// 
        ///  
        ///     Event fired when the value of Region property is changed on Control
        /// 
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlRegionChangedDescr)]
        public event EventHandler RegionChanged { 
            add {
               Events.AddHandler(EventRegionChanged, value); 
            } 
            remove {
                Events.RemoveHandler(EventRegionChanged, value); 
            }
        }

        // Helper function for Rtl 
        /// 
        ///  
        ///  
        ///    [To be supplied.]
        ///  
        [Obsolete("This property has been deprecated. Please use RightToLeft instead. http://go.microsoft.com/fwlink/?linkid=14202")]
        protected internal bool RenderRightToLeft
        {
            get { 
                return true;
            } 
        } 

        ///  
        ///     Determines if the parent's background will be rendered on the label control.
        /// 
        internal bool RenderTransparent {
            get { 
                return GetStyle(ControlStyles.SupportsTransparentBackColor) && this.BackColor.A < 255;
            } 
        } 

        ///  
        /// 
        private bool RenderColorTransparent(Color c) {
            return GetStyle(ControlStyles.SupportsTransparentBackColor) && c.A < 255;
        } 

 
        ///  
        /// Refer VsWhidbey : 440669: This property is required by certain controls (TabPage) to render its transparency using theming API.
        /// We dont want all controls (that are have transparent BackColor) to use theming API to render its background because it has  HUGE PERF cost. 
        /// 
        /// 
        internal virtual bool RenderTransparencyWithVisualStyles {
            get { 
                return false;
            } 
        } 

        ///  
        ///     Represents the bounds of the control that need to be scaled.  Control bounds
        ///     need to be scaled until ScaleControl is called.  They need to be scaled again
        ///     if their bounds change after ScaleControl is called.
        ///  
        internal BoundsSpecified RequiredScaling {
            get { 
                if ((requiredScaling & RequiredScalingEnabledMask) != 0) { 
                    return (BoundsSpecified)(requiredScaling & RequiredScalingMask);
                } 
                return BoundsSpecified.None;
            }
            set {
                byte enableBit = (byte)(requiredScaling & RequiredScalingEnabledMask); 
                requiredScaling = (byte)(((int)value & RequiredScalingMask) | enableBit);
            } 
        } 

        ///  
        ///     Determines if the required scaling property is enabled.  If not,
        ///     RequiredScaling always returns None.
        /// 
        internal bool RequiredScalingEnabled { 
            get {
                return (requiredScaling & RequiredScalingEnabledMask) != 0; 
            } 
            set {
                byte scaling = (byte)(requiredScaling & RequiredScalingMask); 
                requiredScaling = scaling;
                if (value) requiredScaling |= RequiredScalingEnabledMask;
            }
        } 

        ///  
        ///  
        ///     Indicates whether the control should redraw itself when resized.
        ///  
        [
        SRDescription(SR.ControlResizeRedrawDescr)
        ]
        protected bool ResizeRedraw { 
            get {
                return GetStyle( ControlStyles.ResizeRedraw ); 
            } 
            set {
                SetStyle( ControlStyles.ResizeRedraw, value ); 
            }
        }

        ///  
        /// 
        ///    The right coordinate of the control. 
        ///  
        [
        SRCategory(SR.CatLayout), 
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        SRDescription(SR.ControlRightDescr)
        ] 
        public int Right {
            get { 
                return x + width; 
            }
        } 

        /// 
        /// 
        ///     This is used for international applications where the language 
        ///     is written from RightToLeft. When this property is true,
        ///     control placement and text will be from right to left. 
        ///  
        [
        SRCategory(SR.CatAppearance), 
        Localizable(true),
        AmbientValue(RightToLeft.Inherit),
        SRDescription(SR.ControlRightToLeftDescr)
        ] 
        public virtual RightToLeft RightToLeft {
            get { 
                bool found; 
                int rightToLeft = Properties.GetInteger(PropRightToLeft, out found);
                if (!found) { 
                    rightToLeft = (int)RightToLeft.Inherit;
                }

                if (((RightToLeft)rightToLeft) == RightToLeft.Inherit) { 
                    Control parent = ParentInternal;
                    if (parent != null) { 
                        rightToLeft = (int)parent.RightToLeft; 
                    }
                    else { 
                        rightToLeft = (int)DefaultRightToLeft;
                    }
                }
                return (RightToLeft)rightToLeft; 
            }
 
            set { 
                //valid values are 0x0 to 0x2.
                if (!ClientUtils.IsEnumValid(value, (int)value, (int)RightToLeft.No, (int)RightToLeft.Inherit)){ 
                    throw new InvalidEnumArgumentException("RightToLeft", (int)value, typeof(RightToLeft));
                }

                RightToLeft oldValue = RightToLeft; 

                if (Properties.ContainsInteger(PropRightToLeft) || value != RightToLeft.Inherit) { 
                    Properties.SetInteger(PropRightToLeft, (int)value); 
                }
 
                if (oldValue != RightToLeft) {
                    // Setting RTL on a container does not cause the container to change size.
                    // Only the children need to have thier layout updated.
                    using(new LayoutTransaction(this, this, PropertyNames.RightToLeft)) { 
                        OnRightToLeftChanged(EventArgs.Empty);
                    } 
                } 
            }
            } 



        ///  
        /// 
        ///    [To be supplied.] 
        ///  
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlOnRightToLeftChangedDescr)]
        public event EventHandler RightToLeftChanged { 
            add {
                Events.AddHandler(EventRightToLeft, value);
            }
            remove { 
                Events.RemoveHandler(EventRightToLeft, value);
            } 
        } 

 
        /// 
        /// 
        ///     This property controls the scaling of child controls.  If true child controls
        ///     will be scaled when the Scale method on this control is called.  If false, 
        ///     child controls will not be scaled.  The default is true, and you must override
        ///     this property to provide a different value. 
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual bool ScaleChildren { 
            get {
                return true;
            }
        } 

        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        public override ISite Site {
            get { 
                return base.Site;
            }
            set {
                AmbientProperties oldAmbients = AmbientPropertiesService; 
                AmbientProperties newAmbients = null;
 
                if (value != null) { 
                    newAmbients = (AmbientProperties)value.GetService(typeof(AmbientProperties));
                } 


                // If the ambients changed, compare each property.
                // 
                if (oldAmbients != newAmbients) {
                    bool checkFont = !Properties.ContainsObject(PropFont); 
                    bool checkBackColor = !Properties.ContainsObject(PropBackColor); 
                    bool checkForeColor = !Properties.ContainsObject(PropForeColor);
                    bool checkCursor = !Properties.ContainsObject(PropCursor); 

                    Font oldFont = null;
                    Color oldBackColor = Color.Empty;
                    Color oldForeColor = Color.Empty; 
                    Cursor oldCursor = null;
 
                    if (checkFont) { 
                        oldFont = Font;
                    } 

                    if (checkBackColor) {
                        oldBackColor = BackColor;
                    } 

                    if (checkForeColor) { 
                        oldForeColor = ForeColor; 
                    }
 
                    if (checkCursor) {
                        oldCursor = Cursor;
                    }
 
                    Properties.SetObject(PropAmbientPropertiesService, newAmbients);
                    base.Site = value; 
 
                    if (checkFont && !oldFont.Equals(Font)) {
                        OnFontChanged(EventArgs.Empty); 
                    }
                    if (checkForeColor && !oldForeColor.Equals(ForeColor)) {
                        OnForeColorChanged(EventArgs.Empty);
                    } 
                    if (checkBackColor && !oldBackColor.Equals(BackColor)) {
                        OnBackColorChanged(EventArgs.Empty); 
                    } 
                    if (checkCursor && oldCursor.Equals(Cursor)) {
                        OnCursorChanged(EventArgs.Empty); 
                    }
                }
                else {
                    // If the ambients haven't changed, we just set a new site. 
                    //
                    base.Site = value; 
                } 
            }
        } 

        /// 
        /// 
        ///    The size of the control. 
        /// 
        [ 
        SRCategory(SR.CatLayout), 
        Localizable(true),
        SRDescription(SR.ControlSizeDescr) 
        ]
        public Size Size {
            get {
                return new Size(width, height); 
            }
            set { 
                SetBounds(x, y, value.Width, value.Height, BoundsSpecified.Size); 
            }
        } 

        /// 
        /// 
        ///    [To be supplied.] 
        /// 
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlOnSizeChangedDescr)] 
        public event EventHandler SizeChanged { 
            add {
                Events.AddHandler(EventSize, value); 
            }
            remove {
                Events.RemoveHandler(EventSize, value);
            } 
        }
 
        ///  
        /// 
        ///     
        ///       The tab index of
        ///       this control.
        /// 
        [ 
        SRCategory(SR.CatBehavior),
        Localizable(true), 
        MergableProperty(false), 
        SRDescription(SR.ControlTabIndexDescr)
        ] 
        public int TabIndex {
            get {
                return tabIndex == -1 ? 0 : tabIndex;
            } 
            set {
                if (value < 0) { 
                    throw new ArgumentOutOfRangeException("TabIndex", SR.GetString(SR.InvalidLowBoundArgumentEx, "TabIndex", value.ToString(CultureInfo.CurrentCulture), (0).ToString(CultureInfo.CurrentCulture))); 
                }
 
                if (tabIndex != value) {
                    tabIndex = value;
                    OnTabIndexChanged(EventArgs.Empty);
                } 
            }
        } 
 

        ///  
        /// 
        ///    [To be supplied.]
        /// 
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlOnTabIndexChangedDescr)] 
        public event EventHandler TabIndexChanged {
            add { 
                Events.AddHandler(EventTabIndex, value); 
            }
            remove { 
                Events.RemoveHandler(EventTabIndex, value);
            }
        }
 
        /// 
        ///  
        ///    Indicates whether the user can give the focus to this control using the TAB 
        ///       key. This property is read-only.
        ///  
        [
        SRCategory(SR.CatBehavior),
        DefaultValue(true),
        DispId(NativeMethods.ActiveX.DISPID_TABSTOP), 
        SRDescription(SR.ControlTabStopDescr)
        ] 
        public bool TabStop { 
            get {
                return TabStopInternal; 
            }
            set {
                if (TabStop != value) {
                    TabStopInternal = value; 
                    if (IsHandleCreated) SetWindowStyle(NativeMethods.WS_TABSTOP, value);
                    OnTabStopChanged(EventArgs.Empty); 
                } 
            }
        } 

        // Grab out the logical of setting TABSTOP state, so that derived class could use this.
        internal bool TabStopInternal {
            get { 
                return (state & STATE_TABSTOP) != 0;
            } 
            set { 
                if (TabStopInternal != value) {
                    SetState(STATE_TABSTOP, value); 
                }
            }
        }
 
        /// 
        ///  
        ///    [To be supplied.] 
        /// 
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlOnTabStopChangedDescr)] 
        public event EventHandler TabStopChanged {
            add {
                Events.AddHandler(EventTabStop, value);
            } 
            remove {
                Events.RemoveHandler(EventTabStop, value); 
            } 
        }
 


        /// 
        [ 
        SRCategory(SR.CatData),
        Localizable(false), 
        Bindable(true), 
        SRDescription(SR.ControlTagDescr),
        DefaultValue(null), 
        TypeConverter(typeof(StringConverter)),
        ]
        public object Tag {
            get { 
                return Properties.GetObject(PropUserData);
            } 
            set { 
                Properties.SetObject(PropUserData, value);
            } 
        }

        /// 
        ///  
        ///     The current text associated with this control.
        ///  
        [ 
        SRCategory(SR.CatAppearance),
        Localizable(true), 
        Bindable(true),
        DispId(NativeMethods.ActiveX.DISPID_TEXT),
        SRDescription(SR.ControlTextDescr)
        ] 
        public virtual string Text {
            get { 
                if (CacheTextInternal) { 
                    return(text == null) ? "" : text;
                } 
                else {
                    return WindowText;
                }
            } 

            set { 
                if (value == null) { 
                    value = "";
                } 

                if (value == Text) {
                    return;
                } 

                if (CacheTextInternal) { 
                    text = value; 
                }
                WindowText = value; 
                OnTextChanged(EventArgs.Empty);

                if( this.IsMnemonicsListenerAxSourced ){
                    for( Control ctl = this; ctl != null; ctl = ctl.ParentInternal ) { 
                        ActiveXImpl activeXImpl = (ActiveXImpl)ctl.Properties.GetObject(PropActiveXImpl);
                        if( activeXImpl != null ) { 
                            activeXImpl.UpdateAccelTable(); 
                            break;
                        } 
                    }
                }

            } 
        }
 
        ///  
        /// 
        ///    [To be supplied.] 
        /// 
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlOnTextChangedDescr)]
        public event EventHandler TextChanged {
            add { 
                Events.AddHandler(EventText, value);
            } 
            remove { 
                Events.RemoveHandler(EventText, value);
            } 
        }

        /// 
        ///  
        ///     Top coordinate of this control.
        ///  
        [ 
        SRCategory(SR.CatLayout),
        Browsable(false), EditorBrowsable(EditorBrowsableState.Always), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        SRDescription(SR.ControlTopDescr)
        ]
        public int Top { 
            get {
                return y; 
            } 
            set {
                SetBounds(x, value, width, height, BoundsSpecified.Y); 
            }
        }

        ///  
        /// 
        ///     The top level control that contains this control. This doesn't 
        ///     have to be the same as the value returned from getForm since forms 
        ///     can be parented to other controls.
        ///  
        [
        SRCategory(SR.CatBehavior),
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden), 
        SRDescription(SR.ControlTopLevelControlDescr)
        ] 
        public Control TopLevelControl { 
            get {
                Debug.WriteLineIf(IntSecurity.SecurityDemand.TraceVerbose, "GetParent Demanded"); 
                IntSecurity.GetParent.Demand();
                return TopLevelControlInternal;
            }
        } 

        // SECURITY WARNING: This property bypasses a security demand. Use with caution! 
        internal Control TopLevelControlInternal { 
            get {
                Control control = this; 
                while (control != null && !control.GetTopLevel()) {
                    control = control.ParentInternal;
                }
                return control; 
            }
        } 
 
        // SECURITY WARNING: This property bypasses a security demand. Use with caution!
        internal Control TopMostParent { 
            get {
                Control control = this;
                while (control.ParentInternal != null) {
                    control = control.ParentInternal; 
                }
                return control; 
            } 
        }
 

        private BufferedGraphicsContext BufferContext {
            get {
                //This auto upgraged v1 client to per-process doublebuffering logic 
                //
                return BufferedGraphicsManager.Current; 
            } 
        }
 
        /// 
        /// 
        ///    Indicates whether the user interface is in a state to show or hide keyboard
        ///       accelerators. This property is read-only. 
        /// 
        [Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced), DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)] 
        protected internal virtual bool ShowKeyboardCues { 
            get {
                // Controls in design mode always draw their accellerators. 
                if (!IsHandleCreated || DesignMode) {
                    return true;
                    // would be nice to query SystemParametersInfo, but have trouble
                    // getting this to work and this should not really be called before 
                    // handle created anyway
                } 
 
                // How this all works
 
                // uiCuesState contains this control's cached state of whether or not it thinks
                // accelerators/focus cues are turned on. the first 16 bits represent focus cues
                // the second represent keyboard cues.  "F" is the UISTATE_FOCUS_CUES_MASK,
                // "F0" is the UISTATE_KEYBOARD_CUES_MASK 

                // We check here if we have cached state.  If we dont, we need to initialize ourself. 
                // We do this by checking "MenuAccessKeysUnderlined" - we show if this returns true. 

                // If MenuAccessKeysUnderlined returns false, we have to manually call CHANGEUISTATE on the topmost control 
                // Why? Well the way the API seems to work is that it stores in a bit flag for the the hidden
                // state.

                // Details from the Menu keydown to changed value of uiCuesState... 

                // When someone does press the ALT (Menu)/F10 key we will 
                //   Call ProcessUICues on the control that had focus at the time 
                //          ProcessUICues will check the current state of the control using WM_QUERYUISTATE
                //          If WM_QUERYUISTATE indicates that the accelerators are hidden we will 
                //                  either call WM_UPDATEUISTATE or WM_CHANGEUISTATE depending on whether we're hosted or not.
                //          All controls in the heirarchy will be individually called back on WM_UPDATEUISTATE, which will go into WmUpdateUIState.
                //   In WmUpdateUIState, we will update our uiCuesState cached value, which
                //   changes the public value of what we return here for ShowKeyboardCues/ShowFocusCues. 

                if ((uiCuesState & UISTATE_KEYBOARD_CUES_MASK) == 0) { 
 
                        // VSWhidbey 362408 -- if we get in here that means this is the windows bug where the first top
                        // level window doesn't get notified with WM_UPDATEUISTATE 
                        //

                        if (SystemInformation.MenuAccessKeysUnderlined) {
                            uiCuesState |= UISTATE_KEYBOARD_CUES_SHOW; 
                        }
                        else { 
                            // if we're in the hidden state, we need to manufacture an update message so everyone knows it. 
                            //
                            int actionMask = (NativeMethods.UISF_HIDEACCEL | NativeMethods.UISF_HIDEFOCUS) << 16; 
                            uiCuesState |= UISTATE_KEYBOARD_CUES_HIDDEN;

                            // The side effect of this initial state is that adding new controls may clear the accelerator
                            // state (has been this way forever) 
                            UnsafeNativeMethods.SendMessage(new HandleRef(TopMostParent, TopMostParent.Handle),
                                    NativeMethods.WM_CHANGEUISTATE, 
                                    (IntPtr)(actionMask | NativeMethods.UIS_SET), 
                                    IntPtr.Zero);
                        } 
                 }
                 return (uiCuesState & UISTATE_KEYBOARD_CUES_MASK) == UISTATE_KEYBOARD_CUES_SHOW;
            }
        } 

        ///  
        ///  
        ///    Indicates whether the user interface is in a state to show or hide focus
        ///       rectangles. This property is read-only. 
        /// 
        [Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced), DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
        protected internal virtual bool ShowFocusCues {
            get { 
                if (!IsHandleCreated) {
                    return true; 
                    // would be nice to query SystemParametersInfo, but have trouble 
                    // getting this to work and this should not really be called before
                    // handle created anyway 
                }

                // See "How this all works" in ShowKeyboardCues
 
                if ((uiCuesState & UISTATE_FOCUS_CUES_MASK) == 0) {
                    // VSWhidbey 362408 -- if we get in here that means this is the windows bug where the first top 
                    // level window doesn't get notified with WM_UPDATEUISTATE 
                    //
                    if (SystemInformation.MenuAccessKeysUnderlined) { 
                        uiCuesState |= UISTATE_FOCUS_CUES_SHOW;
                    }
                    else {
                        uiCuesState |= UISTATE_FOCUS_CUES_HIDDEN; 

                        // if we're in the hidden state, we need to manufacture an update message so everyone knows it. 
                        // 
                        int actionMask = (NativeMethods.UISF_HIDEACCEL | NativeMethods.UISF_HIDEFOCUS) << 16;
 
                        // The side effect of this initial state is that adding new controls may clear the focus cue state
                        // state (has been this way forever)
                        UnsafeNativeMethods.SendMessage(new HandleRef(TopMostParent, TopMostParent.Handle),
                                NativeMethods.WM_CHANGEUISTATE, 
                                (IntPtr)(actionMask | NativeMethods.UIS_SET),
                                IntPtr.Zero); 
 
                    }
                } 
                return (uiCuesState & UISTATE_FOCUS_CUES_MASK) == UISTATE_FOCUS_CUES_SHOW;
            }
        }
 
        // The parameter used in the call to ShowWindow for this control
        // 
        internal virtual int ShowParams { 
            get {
                return NativeMethods.SW_SHOW; 
            }
        }

 
        /// 
        ///  
        ///     When this property in true the Cursor Property is set to WaitCursor as well as the Cursor Property 
        ///     of all the child controls.
        ///  
        [
        DefaultValue(false),
        EditorBrowsable(EditorBrowsableState.Always),
        Browsable(true), 
        SRCategory(SR.CatAppearance),
        SRDescription(SR.ControlUseWaitCursorDescr), 
        ] 
        public bool UseWaitCursor {
            get { return GetState(STATE_USEWAITCURSOR); } 
            set {
                if (GetState(STATE_USEWAITCURSOR) != value) {
                    SetState(STATE_USEWAITCURSOR, value);
                    ControlCollection controlsCollection = (ControlCollection)Properties.GetObject(PropControlsCollection); 

                    if (controlsCollection != null) { 
                        // PERFNOTE: This is more efficient than using Foreach.  Foreach 
                        // forces the creation of an array subset enum each time we
                        // enumerate 
                        for(int i = 0; i < controlsCollection.Count; i++) {
                            controlsCollection[i].UseWaitCursor = value;
                        }
                    } 
                }
            } 
        } 

        ///  
        ///     Determines whether to use compatible text rendering engine (GDI+) or not (GDI).
        ///     This property overwrites the UseCompatibleTextRenderingDefault switch when set programmatically.
        ///     Exposed publicly only by controls that support GDI text rendering (Label, LinkLabel and some others).
        ///     Observe that this property is NOT virtual (to allow for caching the property value - see LinkLabel) 
        ///     and should be used by controls that support it only (see SupportsUseCompatibleTextRendering).
        ///  
        internal bool UseCompatibleTextRenderingInt { 
            get{
                if (Properties.ContainsInteger(PropUseCompatibleTextRendering)){ 
                    bool found;
                    int value = Properties.GetInteger(PropUseCompatibleTextRendering, out found);
                    if( found ){
                        return value == 1; 
                    }
                } 
 
                return Control.UseCompatibleTextRenderingDefault;
            } 
            set{
                if( SupportsUseCompatibleTextRendering && UseCompatibleTextRenderingInt != value ){
                    Properties.SetInteger(PropUseCompatibleTextRendering, value ? 1 : 0);
                    // Update the preferred size cache since we will be rendering text using a different engine. 
                    LayoutTransaction.DoLayoutIf(AutoSize, ParentInternal, this, PropertyNames.UseCompatibleTextRendering);
                    Invalidate(); 
                } 
            }
        } 

        /// 
        ///     Determines whether the control supports rendering text using GDI+ and GDI.
        ///     This is provided for container controls (PropertyGrid) to iterate through its children to set 
        ///     UseCompatibleTextRendering to the same value if the child control supports it.
        ///  
        internal virtual bool SupportsUseCompatibleTextRendering { 
            get {
                return false; 
            }
        }

        private ControlVersionInfo VersionInfo { 
            get {
                ControlVersionInfo info = (ControlVersionInfo)Properties.GetObject(PropControlVersionInfo); 
                if (info == null) { 
                    info = new ControlVersionInfo(this);
                    Properties.SetObject(PropControlVersionInfo, info); 
                }
                return info;
            }
        } 

        ///  
        ///  
        ///    Indicates whether the control is visible.
        ///  
        [
        SRCategory(SR.CatBehavior),
        Localizable(true),
        SRDescription(SR.ControlVisibleDescr) 
        ]
        public bool Visible { 
            get { 
                return GetVisibleCore();
            } 
            set {
                SetVisibleCore(value);
            }
        } 

        ///  
        ///  
        ///    Occurs when the control becomes visible.
        ///  
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlOnVisibleChangedDescr)]
        public event EventHandler VisibleChanged {
            add {
                Events.AddHandler(EventVisible, value); 
            }
            remove { 
                Events.RemoveHandler(EventVisible, value); 
            }
        } 

        /// 
        /// 
        ///     Wait for the wait handle to receive a signal: throw an exception if the thread is no longer with us. 
        /// 
        private void WaitForWaitHandle(WaitHandle waitHandle) { 
            int threadId = CreateThreadId; 
            Application.ThreadContext ctx = Application.ThreadContext.FromId(threadId);
            if (ctx == null) { 
                // Couldn't find the thread context, so we don't know the state.  We shouldn't throw.
                return;
            }
            IntPtr threadHandle = ctx.GetHandle(); 
            bool processed = false;
            // setting default exitcode to 0, though it won't be accessed in current code below due to short-circuit logic in condition (returnValue will be false when exitCode is undefined) 
            uint exitCode = 0; 
            bool returnValue = false;
            while (!processed) { 
                //Get the thread's exit code, if we found the thread as expected
                if (threadHandle != null) {
                    returnValue = UnsafeNativeMethods.GetExitCodeThread(threadHandle, out exitCode);
                } 
                //If we didn't find the thread, or if GetExitCodeThread failed, we don't know the thread's state:
                //if we don't know, we shouldn't throw. 
                if ((returnValue && exitCode != NativeMethods.STILL_ACTIVE) || AppDomain.CurrentDomain.IsFinalizingForUnload()) { 
                    if (waitHandle.WaitOne(1, false)) {
                        break; 
                    }
                    throw new InvalidAsynchronousStateException(SR.GetString(SR.ThreadNoLongerValid));
                }
 
                //Dev10 Bug 600316: Because Control.Invoke() is not fully thread safe, so it is possible that
                //a ThreadMethodEntry can be sent to a control after it is disposed. 
                if (IsDisposed) { 
                    throw new InvalidOperationException(SR.GetString(SR.ErrorNoMarshalingThread));
                } 

                processed = waitHandle.WaitOne(1000, false);
            }
        } 

 
        ///  
        /// 
        ///     The width of this control. 
        /// 
        [
        SRCategory(SR.CatLayout),
        Browsable(false), EditorBrowsable(EditorBrowsableState.Always), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        SRDescription(SR.ControlWidthDescr) 
        ] 
        public int Width {
            get { 
                return width;
            }
            set {
                SetBounds(x, y, value, height, BoundsSpecified.Width); 
            }
        } 
 
        /// 
        ///     The current exStyle of the hWnd 
        /// 
        /// 
        private int WindowExStyle {
            get { 
                return unchecked((int)(long)UnsafeNativeMethods.GetWindowLong(new HandleRef(this, Handle), NativeMethods.GWL_EXSTYLE));
            } 
            set { 
                UnsafeNativeMethods.SetWindowLong(new HandleRef(this, Handle), NativeMethods.GWL_EXSTYLE, new HandleRef(null, (IntPtr)value));
            } 
        }

        /// 
        ///     The current style of the hWnd 
        /// 
        ///  
        internal int WindowStyle { 
            get {
                return unchecked((int)(long)UnsafeNativeMethods.GetWindowLong(new HandleRef(this, Handle), NativeMethods.GWL_STYLE)); 
            }
            set {
                UnsafeNativeMethods.SetWindowLong(new HandleRef(this, Handle), NativeMethods.GWL_STYLE, new HandleRef(null, (IntPtr)value));
            } 
        }
 
        ///  
        /// 
        ///     The target of Win32 window messages. 
        /// 
        /// 
        [
        SRCategory(SR.CatBehavior), 
        Browsable(false), EditorBrowsable(EditorBrowsableState.Never),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden), 
        SRDescription(SR.ControlWindowTargetDescr) 
        ]
        public IWindowTarget WindowTarget { 
            [SecurityPermission(SecurityAction.LinkDemand, Flags=SecurityPermissionFlag.UnmanagedCode)]
            get {
                return window.WindowTarget;
            } 
            [SecurityPermission(SecurityAction.LinkDemand, Flags=SecurityPermissionFlag.UnmanagedCode)]
            set { 
                window.WindowTarget = value; 
            }
        } 

        /// 
        ///     The current text of the Window; if the window has not yet been created, stores it in the control.
        ///     If the window has been created, stores the text in the underlying win32 control. 
        ///     This property should be used whenever you want to get at the win32 control's text. For all other cases,
        ///     use the Text property - but note that this is overridable, and any of your code that uses it will use 
        ///     the overridden version in controls that subclass your own. 
        /// 
        internal virtual string WindowText { 
            get {

                if (!IsHandleCreated) {
                    if (text == null) { 
                        return "";
                    } 
                    else { 
                        return text;
                    } 
                }

                using (new MultithreadSafeCallScope()) {
 
                    // it's okay to call GetWindowText cross-thread.
                    // 
 
                    int textLen = SafeNativeMethods.GetWindowTextLength(new HandleRef(window, Handle));
 
                    // Check to see if the system supports DBCS character
                    // if so, double the length of the buffer.
                    if (SystemInformation.DbcsEnabled) {
                        textLen = (textLen * 2) + 1; 
                    }
                    StringBuilder sb = new StringBuilder(textLen + 1); 
                    UnsafeNativeMethods.GetWindowText(new HandleRef(window, Handle), sb, sb.Capacity); 
                    return sb.ToString();
                } 
            }
            set {
                if (value == null) value = "";
                if (!WindowText.Equals(value)) { 
                    if (IsHandleCreated) {
                        UnsafeNativeMethods.SetWindowText(new HandleRef(window, Handle), value); 
                    } 
                    else {
                        if (value.Length == 0) { 
                            text = null;
                        }
                        else {
                            text = value; 
                        }
                    } 
                } 
            }
        } 



        ///  
        /// 
        ///    Occurs when the control is clicked. 
        ///  
        [SRCategory(SR.CatAction), SRDescription(SR.ControlOnClickDescr)]
        public event EventHandler Click { 
            add {
                Events.AddHandler(EventClick, value);
            }
            remove { 
                Events.RemoveHandler(EventClick, value);
            } 
        } 

 

        /// 
        /// 
        ///    Occurs when a new control is added. 
        /// 
        [ 
        SRCategory(SR.CatBehavior), 
        Browsable(true),
        EditorBrowsable(EditorBrowsableState.Advanced), 
        SRDescription(SR.ControlOnControlAddedDescr)
        ]
        public event ControlEventHandler ControlAdded {
            add { 
                Events.AddHandler(EventControlAdded, value);
            } 
            remove { 
                Events.RemoveHandler(EventControlAdded, value);
            } 
        }


        ///  
        /// 
        ///    Occurs when a control is removed. 
        ///  
        [
        SRCategory(SR.CatBehavior), 
        Browsable(true),
        EditorBrowsable(EditorBrowsableState.Advanced),
        SRDescription(SR.ControlOnControlRemovedDescr)
        ] 
        public event ControlEventHandler ControlRemoved {
            add { 
                Events.AddHandler(EventControlRemoved, value); 
            }
            remove { 
                Events.RemoveHandler(EventControlRemoved, value);
            }
        }
 
        /// 
        ///  
        ///    [To be supplied.] 
        /// 
        [SRCategory(SR.CatDragDrop), SRDescription(SR.ControlOnDragDropDescr)] 
        public event DragEventHandler DragDrop {
            add {
                Events.AddHandler(EventDragDrop, value);
            } 
            remove {
                Events.RemoveHandler(EventDragDrop, value); 
            } 
        }
 

        /// 
        /// 
        ///    [To be supplied.] 
        /// 
        [SRCategory(SR.CatDragDrop), SRDescription(SR.ControlOnDragEnterDescr)] 
        public event DragEventHandler DragEnter { 
            add {
                Events.AddHandler(EventDragEnter, value); 
            }
            remove {
                Events.RemoveHandler(EventDragEnter, value);
            } 
        }
 
 
        /// 
        ///  
        ///    [To be supplied.]
        /// 
        [SRCategory(SR.CatDragDrop), SRDescription(SR.ControlOnDragOverDescr)]
        public event DragEventHandler DragOver { 
            add {
                Events.AddHandler(EventDragOver, value); 
            } 
            remove {
                Events.RemoveHandler(EventDragOver, value); 
            }
        }

 
        /// 
        ///  
        ///    [To be supplied.] 
        /// 
        [SRCategory(SR.CatDragDrop), SRDescription(SR.ControlOnDragLeaveDescr)] 
        public event EventHandler DragLeave {
            add {
                Events.AddHandler(EventDragLeave, value);
            } 
            remove {
                Events.RemoveHandler(EventDragLeave, value); 
            } 
        }
 
        /// 
        /// 
        ///    [To be supplied.]
        ///  
        [SRCategory(SR.CatDragDrop), SRDescription(SR.ControlOnGiveFeedbackDescr)]
        public event GiveFeedbackEventHandler GiveFeedback { 
            add { 
                Events.AddHandler(EventGiveFeedback, value);
            } 
            remove {
                Events.RemoveHandler(EventGiveFeedback, value);
            }
        } 

 
        ///  
        /// 
        ///    Occurs when a handle is created for the control. 
        /// 
        [SRCategory(SR.CatPrivate), Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced), SRDescription(SR.ControlOnCreateHandleDescr)]
        public event EventHandler HandleCreated {
            add { 
                Events.AddHandler(EventHandleCreated, value);
            } 
            remove { 
                Events.RemoveHandler(EventHandleCreated, value);
            } 
        }


        ///  
        /// 
        ///    Occurs when the control's handle is destroyed. 
        ///  
        [SRCategory(SR.CatPrivate), Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced), SRDescription(SR.ControlOnDestroyHandleDescr)]
        public event EventHandler HandleDestroyed { 
            add {
                Events.AddHandler(EventHandleDestroyed, value);
            }
            remove { 
                Events.RemoveHandler(EventHandleDestroyed, value);
            } 
        } 

 
        /// 
        /// 
        ///    [To be supplied.]
        ///  
        [SRCategory(SR.CatBehavior), SRDescription(SR.ControlOnHelpDescr)]
        public event HelpEventHandler HelpRequested { 
            add { 
                Events.AddHandler(EventHelpRequested, value);
            } 
            remove {
                Events.RemoveHandler(EventHelpRequested, value);
            }
        } 

 
        ///  
        /// 
        ///    [To be supplied.] 
        /// 
        [SRCategory(SR.CatAppearance), Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced), SRDescription(SR.ControlOnInvalidateDescr)]
        public event InvalidateEventHandler Invalidated {
            add { 
                Events.AddHandler(EventInvalidated, value);
            } 
            remove { 
                Events.RemoveHandler(EventInvalidated, value);
            } 
        }

        /// 
        [Browsable(false)] 
        public Size PreferredSize {
            get { return GetPreferredSize(Size.Empty); } 
        } 

        ///  
        [
        SRDescription(SR.ControlPaddingDescr),
        SRCategory(SR.CatLayout),
        Localizable(true) 
        ]
        public Padding Padding { 
            get { return CommonProperties.GetPadding(this, DefaultPadding); } 
            set {
                if (value != Padding) { 
                    CommonProperties.SetPadding(this, value);
                    // Ideally we are being laid out by a LayoutEngine that cares about our preferred size.
                    // We set our LAYOUTISDIRTY bit and ask our parent to refresh us.
                    SetState(STATE_LAYOUTISDIRTY, true); 
                    using (new LayoutTransaction(ParentInternal, this, PropertyNames.Padding)) {
                        OnPaddingChanged(EventArgs.Empty); 
                    } 

                    if(GetState(STATE_LAYOUTISDIRTY)) { 
                        // The above did not cause our layout to be refreshed.  We explicitly refresh our
                        // layout to ensure that any children are repositioned to account for the change
                        // in padding.
                       LayoutTransaction.DoLayout(this, this, PropertyNames.Padding); 
                    }
                } 
            } 
        }
 
        /// 
        /// 
        ///    [To be supplied.]
        ///  
        [SRCategory(SR.CatLayout), SRDescription(SR.ControlOnPaddingChangedDescr)]
        public event EventHandler PaddingChanged { 
            add { 
                Events.AddHandler(EventPaddingChanged, value);
            } 
            remove {
                Events.RemoveHandler(EventPaddingChanged, value);
            }
        } 

 
        ///  
        /// 
        ///    [To be supplied.] 
        /// 
        [SRCategory(SR.CatAppearance), SRDescription(SR.ControlOnPaintDescr)]
        public event PaintEventHandler Paint {
            add { 
                Events.AddHandler(EventPaint, value);
            } 
            remove { 
                Events.RemoveHandler(EventPaint, value);
            } 
        }


        ///  
        /// 
        ///    [To be supplied.] 
        ///  
        [SRCategory(SR.CatDragDrop), SRDescription(SR.ControlOnQueryContinueDragDescr)]
        public event QueryContinueDragEventHandler QueryContinueDrag { 
            add {
                Events.AddHandler(EventQueryContinueDrag, value);
            }
            remove { 
                Events.RemoveHandler(EventQueryContinueDrag, value);
            } 
        } 

        ///  
        /// 
        ///    [To be supplied.]
        /// 
        [SRCategory(SR.CatBehavior), SRDescription(SR.ControlOnQueryAccessibilityHelpDescr)] 
        public event QueryAccessibilityHelpEventHandler QueryAccessibilityHelp {
            add { 
                Events.AddHandler(EventQueryAccessibilityHelp, value); 
            }
            remove { 
                Events.RemoveHandler(EventQueryAccessibilityHelp, value);
            }
        }
 
        /// 
        ///  
        ///    Occurs when the control is double clicked. 
        /// 
        [SRCategory(SR.CatAction), SRDescription(SR.ControlOnDoubleClickDescr)] 
        public event EventHandler DoubleClick {
            add {
                Events.AddHandler(EventDoubleClick, value);
            } 
            remove {
                Events.RemoveHandler(EventDoubleClick, value); 
            } 
        }
 
        /// 
        /// 
        ///    Occurs when the control is entered.
        ///  
        [SRCategory(SR.CatFocus), SRDescription(SR.ControlOnEnterDescr)]
        public event EventHandler Enter { 
            add { 
                Events.AddHandler(EventEnter, value);
            } 
            remove {
                Events.RemoveHandler(EventEnter, value);
            }
        } 

 
        ///  
        /// 
        ///    Occurs when the control receives focus. 
        /// 
        [SRCategory(SR.CatFocus), SRDescription(SR.ControlOnGotFocusDescr), Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced)]
        public event EventHandler GotFocus {
            add { 
                Events.AddHandler(EventGotFocus, value);
            } 
            remove { 
                Events.RemoveHandler(EventGotFocus, value);
            } 
        }


        ///  
        /// 
        ///    Occurs when a key is pressed down while the control has focus. 
        ///  
        [SRCategory(SR.CatKey), SRDescription(SR.ControlOnKeyDownDescr)]
        public event KeyEventHandler KeyDown { 
            add {
                Events.AddHandler(EventKeyDown, value);
            }
            remove { 
                Events.RemoveHandler(EventKeyDown, value);
            } 
        } 

 
        /// 
        /// 
        ///     Occurs when a key is pressed while the control has focus.
        ///  
        [SRCategory(SR.CatKey), SRDescription(SR.ControlOnKeyPressDescr)]
        public event KeyPressEventHandler KeyPress { 
            add { 
                Events.AddHandler(EventKeyPress, value);
            } 
            remove {
                Events.RemoveHandler(EventKeyPress, value);
            }
        } 

 
        ///  
        /// 
        ///     Occurs when a key is released while the control has focus. 
        /// 
        [SRCategory(SR.CatKey), SRDescription(SR.ControlOnKeyUpDescr)]
        public event KeyEventHandler KeyUp {
            add { 
                Events.AddHandler(EventKeyUp, value);
            } 
            remove { 
                Events.RemoveHandler(EventKeyUp, value);
            } 
        }


        ///  
        /// 
        ///  
        [SRCategory(SR.CatLayout), SRDescription(SR.ControlOnLayoutDescr)] 
        public event LayoutEventHandler Layout {
            add { 
                Events.AddHandler(EventLayout, value);
            }
            remove {
                Events.RemoveHandler(EventLayout, value); 
            }
        } 
 

        ///  
        /// 
        ///    Occurs when the control is left.
        /// 
        [SRCategory(SR.CatFocus), SRDescription(SR.ControlOnLeaveDescr)] 
        public event EventHandler Leave {
            add { 
                Events.AddHandler(EventLeave, value); 
            }
            remove { 
                Events.RemoveHandler(EventLeave, value);
            }
        }
 

        ///  
        ///  
        ///    Occurs when the control loses focus.
        ///  
        [SRCategory(SR.CatFocus), SRDescription(SR.ControlOnLostFocusDescr), Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced)]
        public event EventHandler LostFocus {
            add {
                Events.AddHandler(EventLostFocus, value); 
            }
            remove { 
                Events.RemoveHandler(EventLostFocus, value); 
            }
        } 


        /// 
        ///  
        ///    Occurs when the control is mouse clicked.
        ///  
        [SRCategory(SR.CatAction), SRDescription(SR.ControlOnMouseClickDescr)] 
        public event MouseEventHandler MouseClick {
            add { 
                Events.AddHandler(EventMouseClick, value);
            }
            remove {
                Events.RemoveHandler(EventMouseClick, value); 
            }
        } 
 

        ///  
        /// 
        ///    Occurs when the control is mouse double clicked.
        /// 
        [SRCategory(SR.CatAction), SRDescription(SR.ControlOnMouseDoubleClickDescr)] 
        public event MouseEventHandler MouseDoubleClick {
            add { 
                Events.AddHandler(EventMouseDoubleClick, value); 
            }
            remove { 
                Events.RemoveHandler(EventMouseDoubleClick, value);
            }
        }
 

        ///  
        ///  
        ///    Occurs when the control loses mouse Capture.
        ///  
        [SRCategory(SR.CatAction), SRDescription(SR.ControlOnMouseCaptureChangedDescr)]
        public event EventHandler MouseCaptureChanged {
            add {
                Events.AddHandler(EventMouseCaptureChanged, value); 
            }
            remove { 
                Events.RemoveHandler(EventMouseCaptureChanged, value); 
            }
        } 

        /// 
        /// 
        ///    Occurs when the mouse pointer is over the control and a mouse button is 
        ///       pressed.
        ///  
        [SRCategory(SR.CatMouse), SRDescription(SR.ControlOnMouseDownDescr)] 
        public event MouseEventHandler MouseDown {
            add { 
                Events.AddHandler(EventMouseDown, value);
            }
            remove {
                Events.RemoveHandler(EventMouseDown, value); 
            }
        } 
 

        ///  
        /// 
        ///     Occurs when the mouse pointer enters the control.
        /// 
        [SRCategory(SR.CatMouse), SRDescription(SR.ControlOnMouseEnterDescr)] 
        public event EventHandler MouseEnter {
            add { 
                Events.AddHandler(EventMouseEnter, value); 
            }
            remove { 
                Events.RemoveHandler(EventMouseEnter, value);
            }
        }
 

        ///  
        ///  
        ///     Occurs when the mouse pointer leaves the control.
        ///  
        [SRCategory(SR.CatMouse), SRDescription(SR.ControlOnMouseLeaveDescr)]
        public event EventHandler MouseLeave {
            add {
                Events.AddHandler(EventMouseLeave, value); 
            }
            remove { 
                Events.RemoveHandler(EventMouseLeave, value); 
            }
        } 


        /// 
        ///  
        ///     Occurs when the mouse pointer hovers over the contro.
        ///  
        [SRCategory(SR.CatMouse), SRDescription(SR.ControlOnMouseHoverDescr)] 
        public event EventHandler MouseHover {
            add { 
                Events.AddHandler(EventMouseHover, value);
            }
            remove {
                Events.RemoveHandler(EventMouseHover, value); 
            }
        } 
 

        ///  
        /// 
        ///     Occurs when the mouse pointer is moved over the control.
        /// 
        [SRCategory(SR.CatMouse), SRDescription(SR.ControlOnMouseMoveDescr)] 
        public event MouseEventHandler MouseMove {
            add { 
                Events.AddHandler(EventMouseMove, value); 
            }
            remove { 
                Events.RemoveHandler(EventMouseMove, value);
            }
        }
 

        ///  
        ///  
        ///    Occurs when the mouse pointer is over the control and a mouse button is released.
        ///  
        [SRCategory(SR.CatMouse), SRDescription(SR.ControlOnMouseUpDescr)]
        public event MouseEventHandler MouseUp {
            add {
                Events.AddHandler(EventMouseUp, value); 
            }
            remove { 
                Events.RemoveHandler(EventMouseUp, value); 
            }
        } 


        /// 
        ///  
        ///     Occurs when the mouse wheel moves while the control has focus.
        ///  
        [SRCategory(SR.CatMouse), SRDescription(SR.ControlOnMouseWheelDescr), Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced)] 
        public event MouseEventHandler MouseWheel {
            add { 
                Events.AddHandler(EventMouseWheel, value);
            }
            remove {
                Events.RemoveHandler(EventMouseWheel, value); 
            }
        } 
 

        ///  
        /// 
        ///    Occurs when the control is moved.
        /// 
        [SRCategory(SR.CatLayout), SRDescription(SR.ControlOnMoveDescr)] 
        public event EventHandler Move {
            add { 
                Events.AddHandler(EventMove, value); 
            }
            remove { 
                Events.RemoveHandler(EventMove, value);
            }
        }
 
        /// 
        ///    Raised to preview a key down event 
        ///  
        [SRCategory(SR.CatKey), SRDescription(SR.PreviewKeyDownDescr)]
        public event PreviewKeyDownEventHandler PreviewKeyDown { 
            [SecurityPermission(SecurityAction.LinkDemand, Flags=SecurityPermissionFlag.UnmanagedCode)]
            add {
                Events.AddHandler(EventPreviewKeyDown, value);
            } 
            [SecurityPermission(SecurityAction.LinkDemand, Flags=SecurityPermissionFlag.UnmanagedCode)]
            remove { 
                Events.RemoveHandler(EventPreviewKeyDown, value); 
            }
        } 


        /// 
        ///  
        ///    Occurs when the control is resized.
        ///  
        [SRCategory(SR.CatLayout), SRDescription(SR.ControlOnResizeDescr), 
         EditorBrowsable(EditorBrowsableState.Advanced)]
        public event EventHandler Resize { 
            add {
                Events.AddHandler(EventResize, value);
            }
            remove { 
                Events.RemoveHandler(EventResize, value);
            } 
        } 

        ///  
        /// 
        ///    [To be supplied.]
        /// 
        [SRCategory(SR.CatBehavior), SRDescription(SR.ControlOnChangeUICuesDescr)] 
        public event UICuesEventHandler ChangeUICues {
            add { 
                Events.AddHandler(EventChangeUICues, value); 
            }
            remove { 
                Events.RemoveHandler(EventChangeUICues, value);
            }
        }
 
        /// 
        ///  
        ///    [To be supplied.] 
        /// 
        [SRCategory(SR.CatBehavior), SRDescription(SR.ControlOnStyleChangedDescr)] 
        public event EventHandler StyleChanged {
            add {
                Events.AddHandler(EventStyleChanged, value);
            } 
            remove {
                Events.RemoveHandler(EventStyleChanged, value); 
            } 
        }
 
        /// 
        /// 
        ///    [To be supplied.]
        ///  
        [SRCategory(SR.CatBehavior), SRDescription(SR.ControlOnSystemColorsChangedDescr)]
        public event EventHandler SystemColorsChanged { 
            add { 
                Events.AddHandler(EventSystemColorsChanged, value);
            } 
            remove {
                Events.RemoveHandler(EventSystemColorsChanged, value);
            }
        } 

        ///  
        ///  
        ///    Occurs when the control is validating.
        ///  
        [SRCategory(SR.CatFocus), SRDescription(SR.ControlOnValidatingDescr)]
        public event CancelEventHandler Validating {
            add {
                Events.AddHandler(EventValidating, value); 
            }
            remove { 
                Events.RemoveHandler(EventValidating, value); 
            }
        } 


        /// 
        ///  
        ///    Occurs when the control is done validating.
        ///  
        [SRCategory(SR.CatFocus), SRDescription(SR.ControlOnValidatedDescr)] 
        public event EventHandler Validated {
            add { 
                Events.AddHandler(EventValidated, value);
            }
            remove {
                Events.RemoveHandler(EventValidated, value); 
            }
        } 
 
        /// 
        ///  
        ///    [To be supplied.]
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected internal void AccessibilityNotifyClients(AccessibleEvents accEvent, int childID) { 
            AccessibilityNotifyClients(accEvent, NativeMethods.OBJID_CLIENT, childID);
        } 
 
        /// 
        ///  
        ///    [To be supplied.]
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected void AccessibilityNotifyClients(AccessibleEvents accEvent, int objectID, int childID) { 
            if (IsHandleCreated) {
                UnsafeNativeMethods.NotifyWinEvent((int)accEvent, new HandleRef(this, Handle), objectID, childID + 1); 
            } 
        }
 
        /// 
        ///     Helper method for retrieving an ActiveX property.  We abstract these
        ///     to another method so we do not force JIT the ActiveX codebase.
        ///  
        [ResourceExposure(ResourceScope.Process)]
        [ResourceConsumption(ResourceScope.Process)] 
        private IntPtr ActiveXMergeRegion(IntPtr region) { 
            return ActiveXInstance.MergeRegion(region);
        } 

        /// 
        ///     Helper method for retrieving an ActiveX property.  We abstract these
        ///     to another method so we do not force JIT the ActiveX codebase. 
        /// 
        private void ActiveXOnFocus(bool focus) { 
            ActiveXInstance.OnFocus(focus); 
        }
 
        /// 
        ///     Helper method for retrieving an ActiveX property.  We abstract these
        ///     to another method so we do not force JIT the ActiveX codebase.
        ///  
        private void ActiveXViewChanged() {
            ActiveXInstance.ViewChangedInternal(); 
        } 

        #if ACTIVEX_SOURCING 

        //
        // This has been cut from the product.
        // 

        ///  
        ///  
        ///     This is called by regasm to register a control as an ActiveX control.
        ///  
        [ComRegisterFunction()]
        protected static void ActiveXRegister(Type type) {

            if (type == null) { 
                throw new ArgumentNullException("type");
            } 
 
            // If the user is not registering an AX control, then
            // bail now. 
            //
            if (!typeof(Control).IsAssignableFrom(type)) {
                return;
            } 

            // Add the flags that define us as a control to the rest of the 
            // world. 
            //
            RegistryKey clsidKey = Registry.ClassesRoot.OpenSubKey("CLSID", true).CreateSubKey("{" + type.GUID.ToString() + "}"); 
            RegistryKey key = clsidKey.CreateSubKey("Control");
            key.Close();

            key = clsidKey.CreateSubKey("Implemented Categories"); 
            RegistryKey subKey = key.CreateSubKey("{40FC6ED4-2438-11CF-A3DB-080036F12502}"); // CATID_Control
            subKey.Close(); 
            key.Close(); 

            // Calculate MiscStatus bits.  Note that this is a static version 
            // of GetMiscStatus in ActiveXImpl below.  Keep them in [....]!
            //
            int miscStatus = NativeMethods.OLEMISC_ACTIVATEWHENVISIBLE |
                             NativeMethods.OLEMISC_INSIDEOUT | 
                             NativeMethods.OLEMISC_SETCLIENTSITEFIRST |
                             NativeMethods.OLEMISC_RECOMPOSEONRESIZE; 
            if (typeof(IButtonControl).IsAssignableFrom(type)) { 
                miscStatus |= NativeMethods.OLEMISC_ACTSLIKEBUTTON;
            } 

            key = clsidKey.CreateSubKey("MiscStatus");
            key.SetValue("", miscStatus.ToString());
            key.Close(); 

            // Now add the typelib information.  Many containers don't 
            // host Active X controls without a typelib in the registry 
            // (visual basic won't even show it in the control dialog).
            // 
            Guid typeLibGuid = Marshal.GetTypeLibGuidForAssembly(type.Assembly);
            Version assemblyVer = type.Assembly.GetName().Version;

            if (typeLibGuid != Guid.Empty) { 
                key = clsidKey.CreateSubKey("TypeLib");
                key.SetValue("", "{" + typeLibGuid.ToString() + "}"); 
                key.Close(); 
                key = clsidKey.CreateSubKey("Version");
                key.SetValue("", assemblyVer.Major.ToString() + "." + assemblyVer.Minor.ToString()); 
                key.Close();
            }

            clsidKey.Close(); 
        }
        #endif 
 
        /// 
        ///     Helper method for retrieving an ActiveX property.  We abstract these 
        ///     to another method so we do not force JIT the ActiveX codebase.
        /// 
        private void ActiveXUpdateBounds(ref int x, ref int y, ref int width, ref int height, int flags) {
            ActiveXInstance.UpdateBounds(ref x, ref y, ref width, ref height, flags); 
        }
 
        #if ACTIVEX_SOURCING 

        // 
        // This has been cut from the product.
        //

        ///  
        /// 
        ///     This is called by regasm to un-register a control as an ActiveX control. 
        ///  
        [ComUnregisterFunction()]
        protected static void ActiveXUnregister(Type type) { 

            if (type == null) {
                throw new ArgumentNullException("type");
            } 

            // If the user is not unregistering an AX control, then 
            // bail now. 
            //
            if (!typeof(Control).IsAssignableFrom(type)) { 
                return;
            }

            RegistryKey clsidKey = null; 

            // Unregistration should be very robust and unregister what it can.  We eat all exceptions here. 
            // 
            try {
                clsidKey = Registry.ClassesRoot.OpenSubKey("CLSID", true).CreateSubKey("{" + type.GUID.ToString() + "}"); 

                try {
                    clsidKey.DeleteSubKeyTree("Control");
                } 
                catch {
                } 
                try { 
                    clsidKey.DeleteSubKeyTree("Implemented Categories");
                } 
                catch {
                }
                try {
                    clsidKey.DeleteSubKeyTree("MiscStatus"); 
                }
                catch { 
                } 
                try {
                    clsidKey.DeleteSubKeyTree("TypeLib"); 
                }
                catch {
                }
            } 
            finally {
                if (clsidKey != null) { 
                    clsidKey.Close(); 
                }
            } 
        }
        #endif

        ///  
        ///     Assigns a new parent control. Sends out the appropriate property change
        ///     notifications for properties that are affected by the change of parent. 
        ///  
        internal virtual void AssignParent(Control value) {
 
            // Adopt the parent's required scaling bits
            if (value != null) {
                RequiredScalingEnabled = value.RequiredScalingEnabled;
            } 

            if (CanAccessProperties) { 
                // Store the old values for these properties 
                //
                Font oldFont = Font; 
                Color oldForeColor = ForeColor;
                Color oldBackColor = BackColor;
                RightToLeft oldRtl = RightToLeft;
                bool oldEnabled = Enabled; 
                bool oldVisible = Visible;
 
                // Update the parent 
                //
                parent = value; 
                OnParentChanged(EventArgs.Empty);

                if (GetAnyDisposingInHierarchy()) {
                    return; 
                }
 
                // Compare property values with new parent to old values 
                //
                if (oldEnabled != Enabled) { 
                    OnEnabledChanged(EventArgs.Empty);
                }

                // VSWhidbey 320131 
                // When a control seems to be going from invisible -> visible,
                // yet its parent is being set to null and it's not top level, do not raise OnVisibleChanged. 
                bool newVisible = Visible; 

                if (oldVisible != newVisible && !(!oldVisible && newVisible && parent == null && !GetTopLevel())) { 
                    OnVisibleChanged(EventArgs.Empty);
                }
                if (!oldFont.Equals(Font)) {
                    OnFontChanged(EventArgs.Empty); 
                }
                if (!oldForeColor.Equals(ForeColor)) { 
                    OnForeColorChanged(EventArgs.Empty); 
                }
                if (!oldBackColor.Equals(BackColor)) { 
                    OnBackColorChanged(EventArgs.Empty);
                }
                if (oldRtl != RightToLeft) {
                    OnRightToLeftChanged(EventArgs.Empty); 
                }
                if (Properties.GetObject(PropBindingManager) == null && this.Created) { 
                    // We do not want to call our parent's BindingContext property here. 
                    // We have no idea if us or any of our children are using data binding,
                    // and invoking the property would just create the binding manager, which 
                    // we don't need.  We just blindly notify that the binding manager has
                    // changed, and if anyone cares, they will do the comparison at that time.
                    //
                    OnBindingContextChanged(EventArgs.Empty); 
                }
            } 
            else { 
                parent = value;
                OnParentChanged(EventArgs.Empty); 
            }

            SetState(STATE_CHECKEDHOST, false);
            if (ParentInternal != null) ParentInternal.LayoutEngine.InitLayout(this, BoundsSpecified.All); 
        }
 
        ///  
        /// 
        ///    [To be supplied.] 
        /// 
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlOnParentChangedDescr)]
        public event EventHandler ParentChanged {
            add { 
                Events.AddHandler(EventParent, value);
            } 
            remove { 
                Events.RemoveHandler(EventParent, value);
            } 
        }

        /// 
        ///  
        ///     Executes the given delegate on the thread that owns this Control's
        ///     underlying window handle.  The delegate is called asynchronously and this 
        ///     method returns immediately.  You may call this from any thread, even the 
        ///     thread that owns the control's handle.  If the control's handle doesn't
        ///     exist yet, this will follow up the control's parent chain until it finds a 
        ///     control or form that does have a window handle.  If no appropriate handle
        ///     can be found, BeginInvoke will throw an exception.  Exceptions within the
        ///     delegate method are considered untrapped and will be sent to the
        ///     application's untrapped exception handler. 
        ///
        ///     There are five functions on a control that are safe to call from any 
        ///     thread:  GetInvokeRequired, Invoke, BeginInvoke, EndInvoke and CreateGraphics. 
        ///     For all other metohd calls, you should use one of the invoke methods to marshal
        ///     the call to the control's thread. 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        public IAsyncResult BeginInvoke(Delegate method) {
            return BeginInvoke(method, null); 
        }
 
        ///  
        /// 
        ///     Executes the given delegate on the thread that owns this Control's 
        ///     underlying window handle.  The delegate is called asynchronously and this
        ///     method returns immediately.  You may call this from any thread, even the
        ///     thread that owns the control's handle.  If the control's handle doesn't
        ///     exist yet, this will follow up the control's parent chain until it finds a 
        ///     control or form that does have a window handle.  If no appropriate handle
        ///     can be found, BeginInvoke will throw an exception.  Exceptions within the 
        ///     delegate method are considered untrapped and will be sent to the 
        ///     application's untrapped exception handler.
        /// 
        ///     There are five functions on a control that are safe to call from any
        ///     thread:  GetInvokeRequired, Invoke, BeginInvoke, EndInvoke and CreateGraphics.
        ///     For all other metohd calls, you should use one of the invoke methods to marshal
        ///     the call to the control's thread. 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        [SuppressMessage("Microsoft.Security", "CA2123:OverrideLinkDemandsShouldBeIdenticalToBase")] 
        public IAsyncResult BeginInvoke(Delegate method, params Object[] args) {
            using (new MultithreadSafeCallScope()) { 
                Control marshaler = FindMarshalingControl();
                return(IAsyncResult)marshaler.MarshaledInvoke(this, method, args, false);
            }
        } 

        internal void BeginUpdateInternal() { 
            if (!IsHandleCreated) { 
                return;
            } 
            if (updateCount == 0) SendMessage(NativeMethods.WM_SETREDRAW, 0, 0);
            updateCount++;
        }
 
        /// 
        ///  
        ///     Brings this control to the front of the zorder. 
        /// 
        public void BringToFront() { 
            if (parent != null) {
                parent.Controls.SetChildIndex(this, 0);
            }
            else if (IsHandleCreated && GetTopLevel() && SafeNativeMethods.IsWindowEnabled(new HandleRef(window, Handle))) { 
                SafeNativeMethods.SetWindowPos(new HandleRef(window, Handle), NativeMethods.HWND_TOP, 0, 0, 0, 0,
                                               NativeMethods.SWP_NOMOVE | NativeMethods.SWP_NOSIZE); 
            } 
        }
 
        /// 
        ///     Specifies whether this control can process the mnemonic or not.  A condition to process a mnemonic is that
        ///     all controls in the parent chain can do it too, but since the semantics for this function can be overriden,
        ///     we need to call the method on the parent 'recursively' (not exactly since it is not necessarily the same method). 
        /// 
        internal virtual bool CanProcessMnemonic() { 
#if DEBUG 
            TraceCanProcessMnemonic();
#endif 
            if( !this.Enabled || !this.Visible) {
                return false;
            }
 
            if( this.parent != null ){
                return this.parent.CanProcessMnemonic(); 
            } 

            return true; 
        }

        // Package scope to allow AxHost to override
        // 
        internal virtual bool CanSelectCore() {
            if ((controlStyle & ControlStyles.Selectable) != ControlStyles.Selectable) { 
                return false; 
            }
 
            for (Control ctl = this; ctl != null; ctl = ctl.parent) {
                if (!ctl.Enabled || !ctl.Visible) {
                    return false;
                } 
            }
 
            return true; 
        }
 
        /// 
        ///     Searches the parent/owner tree for bottom to find any instance
        ///     of toFind in the parent/owner tree.
        ///  
        internal static void CheckParentingCycle(Control bottom, Control toFind) {
            Form lastOwner = null; 
            Control lastParent = null; 

            for (Control ctl = bottom; ctl != null; ctl = ctl.ParentInternal) { 
                lastParent = ctl;
                if (ctl == toFind) {
                    throw new ArgumentException(SR.GetString(SR.CircularOwner));
                } 
            }
 
            if (lastParent != null) { 
                if (lastParent is Form) {
                    Form f = (Form)lastParent; 
                    for (Form form = f; form != null; form = form.OwnerInternal) {
                        lastOwner = form;
                        if (form == toFind) {
                            throw new ArgumentException(SR.GetString(SR.CircularOwner)); 
                        }
                    } 
                } 
            }
 
            if (lastOwner != null) {
                if (lastOwner.ParentInternal != null) {
                    CheckParentingCycle(lastOwner.ParentInternal, toFind);
                } 
            }
        } 
        ///  
        /// 
        ///  
        private void ChildGotFocus(Control child) {
            if (IsActiveX) {
                ActiveXOnFocus(true);
            } 
            if (parent != null) {
                parent.ChildGotFocus(child); 
            } 
        }
 
        /// 
        /// 
        ///    Verifies if a control is a child of this control.
        ///  
        public bool Contains(Control ctl) {
            while (ctl != null) { 
                ctl = ctl.ParentInternal; 
                if (ctl == null) {
                    return false; 
                }
                if (ctl == this) {
                    return true;
                } 
            }
            return false; 
        } 

        ///  
        /// 
        ///     constructs the new instance of the accessibility object for this control. Subclasses
        ///     should not call base.CreateAccessibilityObject.
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual AccessibleObject CreateAccessibilityInstance() { 
            return new ControlAccessibleObject(this); 
        }
 
        /// 
        /// 
        ///     Constructs the new instance of the Controls collection objects. Subclasses
        ///     should not call base.CreateControlsInstance. 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual ControlCollection CreateControlsInstance() { 
            return new System.Windows.Forms.Control.ControlCollection(this);
        } 

        /// 
        /// 
        ///     Creates a Graphics for this control. The control's brush, font, foreground 
        ///     color and background color become the default values for the Graphics.
        ///     The returned Graphics must be disposed through a call to its dispose() 
        ///     method when it is no longer needed.  The Graphics Object is only valid for 
        ///     the duration of the current window's message.
        ///  
        [ResourceExposure(ResourceScope.Process)]
        [ResourceConsumption(ResourceScope.Process)]
        public System.Drawing.Graphics CreateGraphics() {
            using (new MultithreadSafeCallScope()) 
            {
                Debug.WriteLineIf(IntSecurity.SecurityDemand.TraceVerbose, "CreateGraphicsForControl Demanded"); 
                IntSecurity.CreateGraphicsForControl.Demand(); 
                return CreateGraphicsInternal();
            } 
        }


        // SECURITY WARNING: This property bypasses a security demand. Use with caution! 
        [ResourceExposure(ResourceScope.Process)]
        [ResourceConsumption(ResourceScope.Process)] 
        internal System.Drawing.Graphics CreateGraphicsInternal() { 
            return Graphics.FromHwndInternal(this.Handle);
        } 

        /// 
        /// 
        ///     Creates a handle for this control. This method is called by the .NET Framework, this should 
        ///     not be called. Inheriting classes should always call base.createHandle when
        ///     overriding this method. 
        ///  
        [
        EditorBrowsable(EditorBrowsableState.Advanced), 
        UIPermission(SecurityAction.InheritanceDemand, Window=UIPermissionWindow.AllWindows)
        ]
        protected virtual void CreateHandle() {
            IntPtr userCookie = IntPtr.Zero; 

            if (GetState(STATE_DISPOSED)) { 
                throw new System.ObjectDisposedException(GetType().Name); 
            }
 
            if (GetState(STATE_CREATINGHANDLE)) {
                return;
            }
 
            Rectangle originalBounds;
 
            try { 
                SetState(STATE_CREATINGHANDLE, true);
 
                originalBounds = this.Bounds;

                if (Application.UseVisualStyles) {
                    // Activate theming scope to get theming for controls at design time and when hosted in browser. 
                    // NOTE: If a theming context is already active, this call is very fast, so shouldn't be a perf issue.
                    userCookie = UnsafeNativeMethods.ThemingScope.Activate(); 
                } 

                CreateParams cp = CreateParams; 
                SetState(STATE_MIRRORED, (cp.ExStyle & NativeMethods.WS_EX_LAYOUTRTL) != 0);

                // Adjust for scrolling of parent...
                // 
                if (parent != null) {
                    Rectangle parentClient = parent.ClientRectangle; 
 
                    if (!parentClient.IsEmpty) {
                        if (cp.X != NativeMethods.CW_USEDEFAULT) { 
                            cp.X -= parentClient.X;
                        }
                        if (cp.Y != NativeMethods.CW_USEDEFAULT) {
                            cp.Y -= parentClient.Y; 
                        }
                    } 
                } 

                // And if we are WS_CHILD, ensure we have a parent handle. 
                //
                if (cp.Parent == IntPtr.Zero && (cp.Style & NativeMethods.WS_CHILD) != 0) {
                    Debug.Assert((cp.ExStyle & NativeMethods.WS_EX_MDICHILD) == 0, "Can't put MDI child forms on the parking form");
                    Application.ParkHandle(cp); 
                }
 
                window.CreateHandle(cp); 

                UpdateReflectParent(true); 

            }
            finally {
                SetState(STATE_CREATINGHANDLE, false); 
                UnsafeNativeMethods.ThemingScope.Deactivate(userCookie);
            } 
 
            // VSWhidbey #121382 - For certain controls (e.g., ComboBox) CreateWindowEx
            // may cause the control to resize.  WM_SETWINDOWPOSCHANGED takes care of 
            // the control being resized, but our layout container may need a refresh as well.
            if (this.Bounds != originalBounds) {
                LayoutTransaction.DoLayout(ParentInternal, this, PropertyNames.Bounds);
            } 
        }
 
        ///  
        /// 
        ///     Forces the creation of the control. This includes the creation of the handle, 
        ///     and any child controls.
        /// 
        public void CreateControl() {
            bool controlIsAlreadyCreated = this.Created; 
            CreateControl(false);
 
            if (Properties.GetObject(PropBindingManager) == null && ParentInternal != null && !controlIsAlreadyCreated) { 
                // We do not want to call our parent's BindingContext property here.
                // We have no idea if us or any of our children are using data binding, 
                // and invoking the property would just create the binding manager, which
                // we don't need.  We just blindly notify that the binding manager has
                // changed, and if anyone cares, they will do the comparison at that time.
                OnBindingContextChanged(EventArgs.Empty); 
            }
        } 
 
        /// 
        ///     Forces the creation of the control. This includes the creation of the handle, 
        ///     and any child controls.
        /// 
        ///     Determines whether we should create the handle after checking the Visible
        ///     property of the control or not. 
        /// 
        ///  
        internal void CreateControl(bool fIgnoreVisible) { 
            bool ready = (state & STATE_CREATED) == 0;
 
            // PERF: Only "create" the control if it is
            //     : visible. This has the effect of delayed handle creation of
            //     : hidden controls.
            // 
            ready = ready && Visible;
 
            if (ready || fIgnoreVisible) { 
                state |= STATE_CREATED;
                bool createdOK = false; 
                try {
                    if (!IsHandleCreated) CreateHandle();

                    // 58041 - must snapshot this array because 
                    // z-order updates from Windows may rearrange it!
                    // 
                    ControlCollection controlsCollection = (ControlCollection)Properties.GetObject(PropControlsCollection); 

                    if (controlsCollection != null) { 
                        Control[] controlSnapshot = new Control[controlsCollection.Count];
                        controlsCollection.CopyTo(controlSnapshot, 0);

                        foreach(Control ctl in controlSnapshot) { 
                            if (ctl.IsHandleCreated) {
                                ctl.SetParentHandle(Handle); 
                            } 
                            ctl.CreateControl(fIgnoreVisible);
                        } 
                    }

                    createdOK = true;
                } 
                finally {
                    if (!createdOK) 
                        state &= (~STATE_CREATED); 
                }
                OnCreateControl(); 
            }
        }

 
        /// 
        ///  
        ///     Sends the message to the default window proc. 
        /// 
        /* Primarily here for Form to override */ 
        [
            SecurityPermission(SecurityAction.InheritanceDemand, Flags=SecurityPermissionFlag.UnmanagedCode),
            SecurityPermission(SecurityAction.LinkDemand, Flags=SecurityPermissionFlag.UnmanagedCode),
            EditorBrowsable(EditorBrowsableState.Advanced) 
        ]
        protected virtual void DefWndProc(ref Message m) { 
            window.DefWndProc(ref m); 
        }
 

        /// 
        /// 
        ///     Destroys the handle associated with this control. Inheriting classes should 
        ///     always call base.destroyHandle.
        ///  
        [ 
            SecurityPermission(SecurityAction.InheritanceDemand, Flags=SecurityPermissionFlag.UnmanagedCode),
            UIPermission(SecurityAction.LinkDemand, Window=UIPermissionWindow.AllWindows), 
            EditorBrowsable(EditorBrowsableState.Advanced)
        ]
        protected virtual void DestroyHandle() {
 
            if (RecreatingHandle) {
                if (threadCallbackList != null) { 
                    // See if we have a thread marshaling request pending.  If so, we will need to 
                    // re-post it after recreating the handle.
                    // 
                    lock (threadCallbackList) {
                        if (threadCallbackMessage != 0) {
                            NativeMethods.MSG msg = new NativeMethods.MSG();
                            if (UnsafeNativeMethods.PeekMessage(ref msg, new HandleRef(this, Handle), threadCallbackMessage, 
                                                          threadCallbackMessage, NativeMethods.PM_NOREMOVE)) {
 
                                SetState(STATE_THREADMARSHALLPENDING, true); 
                            }
                        } 
                    }
                }
            }
 
            // If we're not recreating the handle, then any items in the thread callback list will
            // be orphaned.  An orphaned item is bad, because it will cause the thread to never 
            // wake up.  So, we put exceptions into all these items and wake up all threads. 
            // If we are recreating the handle, then we're fine because recreation will re-post
            // the thread callback message to the new handle for us. 
            //
            if (!RecreatingHandle) {
                if (threadCallbackList != null) {
                    lock (threadCallbackList) { 
                        Exception ex = new System.ObjectDisposedException(GetType().Name);
 
                        while (threadCallbackList.Count > 0) { 
                            ThreadMethodEntry entry = (ThreadMethodEntry)threadCallbackList.Dequeue();
                            entry.exception = ex; 
                            entry.Complete();
                        }
                    }
                } 
            }
 
            if (0 != (NativeMethods.WS_EX_MDICHILD & (int)(long)UnsafeNativeMethods.GetWindowLong(new HandleRef(window, InternalHandle), NativeMethods.GWL_EXSTYLE))) { 
                UnsafeNativeMethods.DefMDIChildProc(InternalHandle, NativeMethods.WM_CLOSE, IntPtr.Zero, IntPtr.Zero);
            } 
            else {
                window.DestroyHandle();
            }
 
            trackMouseEvent = null;
        } 
 
        /// 
        ///  
        ///    Disposes of the resources (other than memory) used by the
        ///    
        ///    .
        ///  
        protected override void Dispose(bool disposing) {
            if (GetState(STATE_OWNCTLBRUSH)) { 
                object backBrush = Properties.GetObject(PropBackBrush); 
                if (backBrush != null) {
                    IntPtr p = (IntPtr)backBrush; 
                    if (p != IntPtr.Zero) {
                        SafeNativeMethods.DeleteObject(new HandleRef(this, p));
                    }
                    Properties.SetObject(PropBackBrush, null); 
                }
            } 
 
            //set reflectparent = null regardless of whether we are in the finalizer thread or not.
            UpdateReflectParent(false); 
            if (disposing) {
                if (GetState(STATE_DISPOSING)) {
                    return;
                } 

                if (GetState(STATE_CREATINGHANDLE)) { 
                    throw new InvalidOperationException(SR.GetString(SR.ClosingWhileCreatingHandle, "Dispose")); 
                    // I imagine most subclasses will get themselves in a half disposed state
                    // if this exception is thrown, but things will be equally broken if we ignore this error, 
                    // and this way at least the user knows what they did wrong.
                }

                SetState(STATE_DISPOSING, true); 
                this.SuspendLayout();
                try { 
                    DisposeAxControls(); 

                    ContextMenu contextMenu = (ContextMenu)Properties.GetObject(PropContextMenu); 
                    if (contextMenu != null) {
                        contextMenu.Disposed -= new EventHandler(DetachContextMenu);
                    }
 
                    ResetBindings();
 
                    if (IsHandleCreated) DestroyHandle(); 

                    if (parent != null) { 
                        parent.Controls.Remove(this);
                    }

                    ControlCollection controlsCollection = (ControlCollection)Properties.GetObject(PropControlsCollection); 

                    if (controlsCollection != null) { 
 
                        // PERFNOTE: This is more efficient than using Foreach.  Foreach
                        // forces the creation of an array subset enum each time we 
                        // enumerate
                        for(int i = 0; i < controlsCollection.Count; i++) {
                            Control ctl = controlsCollection[i];
                            ctl.parent = null; 
                            ctl.Dispose();
                        } 
                        Properties.SetObject(PropControlsCollection, null); 
                    }
 
                    base.Dispose(disposing);
                }
                finally {
                    this.ResumeLayout(false); 
                    SetState(STATE_DISPOSING, false);
                    SetState(STATE_DISPOSED, true); 
                } 
            }
            else { 

#if FINALIZATION_WATCH
                if (!GetState(STATE_DISPOSED)) {
                    Debug.Fail("Control of type '" + GetType().FullName +"' is being finalized that wasn't disposed\n" + allocationSite); 
                }
#endif 
                // This same post is done in NativeWindow's finalize method, so if you change 
                // it, change it there too.
                // 
                if (window != null) {
                    window.ForceExitMessageLoop();
                }
                base.Dispose(disposing); 
            }
        } 
 
        // Package scope to allow AxHost to override.
        // 
        internal virtual void DisposeAxControls() {
            ControlCollection controlsCollection = (ControlCollection)Properties.GetObject(PropControlsCollection);

            if (controlsCollection != null) { 
                // PERFNOTE: This is more efficient than using Foreach.  Foreach
                // forces the creation of an array subset enum each time we 
                // enumerate 
                for(int i = 0; i < controlsCollection.Count; i++) {
                    controlsCollection[i].DisposeAxControls(); 
                }
            }
        }
 
        /// 
        ///  
        ///     Begins a drag operation. The allowedEffects determine which 
        ///     drag operations can occur. If the drag operation needs to interop
        ///     with applications in another process, data should either be 
        ///     a base managed class (String, Bitmap, or Metafile) or some Object
        ///     that implements System.Runtime.Serialization.ISerializable. data can also be any Object that
        ///     implements System.Windows.Forms.IDataObject.
        ///  
        [UIPermission(SecurityAction.Demand, Clipboard=UIPermissionClipboard.OwnClipboard)]
        public DragDropEffects DoDragDrop(Object data, DragDropEffects allowedEffects) { 
            int[] finalEffect = new int[] {(int)DragDropEffects.None}; 
            UnsafeNativeMethods.IOleDropSource dropSource = new DropSource( this );
            IComDataObject dataObject = null; 

            if (data is IComDataObject) {
                dataObject = (IComDataObject)data;
            } 
            else {
 
                DataObject iwdata = null; 
                if (data is IDataObject) {
                    iwdata = new DataObject((IDataObject)data); 
                }
                else {
                    iwdata = new DataObject();
                    iwdata.SetData(data); 
                }
                dataObject = (IComDataObject)iwdata; 
            } 

            try { 
                SafeNativeMethods.DoDragDrop(dataObject, dropSource, (int)allowedEffects, finalEffect);
            }
            catch (Exception e) {
                if (ClientUtils.IsSecurityOrCriticalException(e)) { 
                    throw;
                } 
            } 

            return(DragDropEffects)finalEffect[0]; 
        }

        /// 
        ///  
        //      Trinity are currently calling IViewObject::Draw in order to render controls on Word & Excel
        //      before they are in place active. However this method is private and they need a public way to do this. 
        //      This means that we will need to add a public method to control that supports rendering to a Bitmap: 
        //      public virtual void DrawToBitmap(Bitmap bmp, RectangleF targetBounds)
        //      where target bounds is the bounds within which the control should render. 
        /// 
        [
            SuppressMessage("Microsoft.Usage", "CA2208:InstantiateArgumentExceptionsCorrectly"),
            SuppressMessage("Microsoft.Design", "CA1011:ConsiderPassingBaseTypesAsParameters"),          // Using Bitmap instead of Image intentionally 
            SuppressMessage("Microsoft.Globalization", "CA1303:DoNotPassLiteralsAsLocalizedParameters"), // targetBounds is the name of the param passed in.
                                                                                                         // So we don't have to localize it. 
            UIPermission(SecurityAction.Demand, Window=UIPermissionWindow.AllWindows) 
        ]
        public void DrawToBitmap(Bitmap bitmap, Rectangle targetBounds) { 

            if (bitmap == null) {
                throw new ArgumentNullException("bitmap");
            } 

            if (targetBounds.Width <= 0 || targetBounds.Height <= 0 
                || targetBounds.X < 0 || targetBounds.Y < 0) { 
                throw new ArgumentException("targetBounds");
            } 

            if (!IsHandleCreated) {
                CreateHandle();
            } 

 
            int width = Math.Min(this.Width, targetBounds.Width); 
            int height = Math.Min(this.Height, targetBounds.Height);
 
            Bitmap image = new Bitmap(width, height, bitmap.PixelFormat);

            using (Graphics g = Graphics.FromImage(image)) {
                IntPtr hDc = g.GetHdc(); 
                //send the actual wm_print message
                UnsafeNativeMethods.SendMessage(new HandleRef(this, this.Handle), NativeMethods.WM_PRINT, (IntPtr)hDc, 
                    (IntPtr)(NativeMethods.PRF_CHILDREN | NativeMethods.PRF_CLIENT | NativeMethods.PRF_ERASEBKGND | NativeMethods.PRF_NONCLIENT)); 

                //now BLT the result to the destination bitmap. 
                using (Graphics destGraphics = Graphics.FromImage(bitmap)) {
                    IntPtr desthDC = destGraphics.GetHdc();
                    SafeNativeMethods.BitBlt(new HandleRef(destGraphics, desthDC), targetBounds.X, targetBounds.Y, width, height,
                                             new HandleRef(g, hDc), 0, 0, 0xcc0020); 
                    destGraphics.ReleaseHdcInternal(desthDC);
                } 
 
                g.ReleaseHdcInternal(hDc);
            } 
        }

        /// 
        ///  
        ///     Retrieves the return value of the asynchronous operation
        ///     represented by the IAsyncResult interface passed. If the 
        ///     async operation has not been completed, this function will 
        ///     block until the result is available.
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        public Object EndInvoke(IAsyncResult asyncResult) {
            using (new MultithreadSafeCallScope())
            { 
                if (asyncResult == null) {
                    throw new ArgumentNullException("asyncResult"); 
                } 

                ThreadMethodEntry entry = asyncResult as ThreadMethodEntry; 
                if (entry == null) {
                    throw new ArgumentException(SR.GetString(SR.ControlBadAsyncResult),"asyncResult");
                }
                Debug.Assert(this == entry.caller, "Called BeginInvoke on one control, and the corresponding EndInvoke on a different control"); 

                if (!asyncResult.IsCompleted) { 
                    int pid; // ignored 
                    Control marshaler = FindMarshalingControl();
                    if (SafeNativeMethods.GetWindowThreadProcessId(new HandleRef(marshaler, marshaler.Handle), out pid) == SafeNativeMethods.GetCurrentThreadId()) { 
                        marshaler.InvokeMarshaledCallbacks();
                    }
                    else {
                        marshaler = entry.marshaler; 
                        marshaler.WaitForWaitHandle(asyncResult.AsyncWaitHandle);
                    } 
                } 

                Debug.Assert(asyncResult.IsCompleted, "Why isn't this asyncResult done yet?"); 
                if (entry.exception != null) {
                    throw entry.exception;
                }
                return entry.retVal; 
            }
        } 
 
        internal bool EndUpdateInternal() {
            return EndUpdateInternal(true); 
        }

        internal bool EndUpdateInternal(bool invalidate) {
            if (updateCount > 0) { 
                Debug.Assert(IsHandleCreated, "Handle should be created by now");
                updateCount--; 
                if (updateCount == 0) { 
                    SendMessage(NativeMethods.WM_SETREDRAW, -1, 0);
                    if (invalidate) { 
                        Invalidate();
                    }

                } 
                return true;
            } 
            else { 
                return false;
            } 
        }

        /// 
        ///  
        ///     Retrieves the form that this control is on. The control's parent
        ///     may not be the same as the form. 
        ///  
        [UIPermission(SecurityAction.Demand, Window=UIPermissionWindow.AllWindows)]
        public Form FindForm() { 
            return FindFormInternal();
        }

        // SECURITY WARNING: This method bypasses a security demand. Use with caution! 
        internal Form FindFormInternal() {
            Control cur = this; 
            while (cur != null && !(cur is Form) ) { 
                cur = cur.ParentInternal;
            } 
            return (Form)cur;
        }

        ///  
        ///     Attempts to find a control Object that we can use to marshal
        ///     calls.  We must marshal calls to a control with a window 
        ///     handle, so we traverse up the parent chain until we find one. 
        ///     Failing that, we just return ouselves.
        ///  
        /// 
        private Control FindMarshalingControl() {
            //
            lock(this) { 
                Control c = this;
 
                while (c != null && !c.IsHandleCreated) { 
                    Control p = c.ParentInternal;
                    c = p; 
                }

                if (c == null) {
                    // No control with a created handle.  We 
                    // just use our own control.  MarshaledInvoke
                    // will throw an exception because there 
                    // is no handle. 
                    //
                    c = this; 
                }
                else {
                    Debug.Assert(c.IsHandleCreated, "FindMarshalingControl chose a bad control.");
                } 

                return(Control)c; 
            } 
        }
 
        /// 
        /// 
        ///    [To be supplied.]
        ///  
        protected bool GetTopLevel() {
            return(state & STATE_TOPLEVEL) != 0; 
        } 

        ///  
        ///     Used by AxHost to fire the CreateHandle event.
        /// 
        /// 
        internal void RaiseCreateHandleEvent(EventArgs e) { 
            EventHandler handler = (EventHandler)Events[EventHandleCreated];
            if (handler != null) handler(this, e); 
        } 

        ///  
        /// 
        ///     Raises the event associated with key with the event data of
        ///     e and a sender of this control.
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected void RaiseKeyEvent(object key, KeyEventArgs e) { 
            KeyEventHandler handler = (KeyEventHandler)Events[key]; 
            if (handler != null) handler(this, e);
        } 

        /// 
        /// 
        ///     Raises the event associated with key with the event data of 
        ///     e and a sender of this control.
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected void RaiseMouseEvent(object key, MouseEventArgs e) {
            MouseEventHandler handler = (MouseEventHandler)Events[key]; 
            if (handler != null) handler(this, e);
        }

        ///  
        /// 
        ///     Sets focus to the control. 
        ///    Attempts to set focus to this control. 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        public bool Focus() {
            Debug.WriteLineIf(Control.FocusTracing.TraceVerbose, "Control::Focus - " + this.Name);
            Debug.WriteLineIf(IntSecurity.SecurityDemand.TraceVerbose, "ModifyFocus Demanded");
            IntSecurity.ModifyFocus.Demand(); 

            //here, we call our internal method (which form overrides) 
            //see comments in FocusInternal 
            //
            return FocusInternal(); 
        }

        /// 
        ///    Internal method for setting focus to the control. 
        ///    Form overrides this method - because MDI child forms
        ///    need to be focused by calling the MDIACTIVATE message. 
        ///  
        // SECURITY WARNING: This method bypasses a security demand. Use with caution!
        internal virtual bool FocusInternal() { 
            Debug.WriteLineIf(Control.FocusTracing.TraceVerbose, "Control::FocusInternal - " + this.Name);
            if (CanFocus){
                UnsafeNativeMethods.SetFocus(new HandleRef(this, Handle));
            } 
            if (Focused && this.ParentInternal != null) {
                IContainerControl c = this.ParentInternal.GetContainerControlInternal(); 
 
                if (c != null) {
                    if (c is ContainerControl) { 
                        ((ContainerControl)c).SetActiveControlInternal(this);
                    }
                    else {
                        c.ActiveControl = this; 
                    }
                } 
            } 

 
            return Focused;
        }

        ///  
        /// 
        ///     Returns the control that is currently associated with handle. 
        ///     This method will search up the HWND parent chain until it finds some 
        ///     handle that is associated with with a control. This method is more
        ///     robust that fromHandle because it will correctly return controls 
        ///     that own more than one handle.
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        public static Control FromChildHandle(IntPtr handle) { 
            Debug.WriteLineIf(IntSecurity.SecurityDemand.TraceVerbose, "ControlFromHandleOrLocation Demanded");
            IntSecurity.ControlFromHandleOrLocation.Demand(); 
            return FromChildHandleInternal(handle); 
        }
 
        // SECURITY WARNING: This method bypasses a security demand. Use with caution!
        internal static Control FromChildHandleInternal(IntPtr handle) {
            while (handle != IntPtr.Zero) {
                Control ctl = FromHandleInternal(handle); 
                if (ctl != null) return ctl;
                handle = UnsafeNativeMethods.GetAncestor(new HandleRef(null, handle), NativeMethods.GA_PARENT); 
            } 
            return null;
        } 

        /// 
        /// 
        ///     Returns the control that is currently associated with handle. 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        public static Control FromHandle(IntPtr handle) { 
            Debug.WriteLineIf(IntSecurity.SecurityDemand.TraceVerbose, "ControlFromHandleOrLocation Demanded");
            IntSecurity.ControlFromHandleOrLocation.Demand(); 
            return FromHandleInternal(handle);
        }

        // SECURITY WARNING: This method bypasses a security demand. Use with caution! 
        internal static Control FromHandleInternal(IntPtr handle) {
            NativeWindow w = NativeWindow.FromHandle(handle); 
            while (w != null && !(w is ControlNativeWindow)) { 
                w = w.PreviousWindow;
            } 

            if (w is ControlNativeWindow) {
                return((ControlNativeWindow)w).GetControl();
            } 
            return null;
        } 
 
        // GetPreferredSize and SetBoundsCore call this method to allow controls to self impose
        // constraints on their size. 
        internal Size ApplySizeConstraints(int width, int height) {
            return ApplyBoundsConstraints(0,0,width, height).Size;
        }
 

        // GetPreferredSize and SetBoundsCore call this method to allow controls to self impose 
        // constraints on their size. 
        internal Size ApplySizeConstraints(Size proposedSize) {
            return ApplyBoundsConstraints(0,0,proposedSize.Width,proposedSize.Height).Size; 
        }

        internal virtual Rectangle ApplyBoundsConstraints(int suggestedX, int suggestedY, int proposedWidth, int proposedHeight) {
 
            // COMPAT: 529991 - in Everett we would allow you to set negative values in pre-handle mode
            // in Whidbey, if you've set Min/Max size we will constrain you to 0,0.  Everett apps didnt 
            // have min/max size on control, which is why this works. 
            if (MaximumSize != Size.Empty || MinimumSize != Size.Empty) {
                Size maximumSize = LayoutUtils.ConvertZeroToUnbounded(MaximumSize); 
                Rectangle newBounds = new Rectangle(suggestedX, suggestedY, 0,0);

                // Clip the size to maximum and inflate it to minimum as necessary.
                newBounds.Size = LayoutUtils.IntersectSizes(new Size(proposedWidth,proposedHeight), maximumSize); 
                newBounds.Size = LayoutUtils.UnionSizes(newBounds.Size, MinimumSize);
 
                return newBounds; 
            }
 
            return new Rectangle(suggestedX, suggestedY, proposedWidth, proposedHeight);
        }

 

        ///  
        ///  
        ///     Retrieves the child control that is located at the specified client
        ///     coordinates. 
        /// 
        public Control GetChildAtPoint(Point pt, GetChildAtPointSkip skipValue) {
            int value = (int)skipValue;
            // Since this is a Flags Enumeration... the only way to validate skipValue is by checking if its within the range. 
            if(value < 0 || value > 7)
            { 
                throw new InvalidEnumArgumentException("skipValue", value, typeof(GetChildAtPointSkip)); 
            }
 
            IntPtr hwnd = UnsafeNativeMethods.ChildWindowFromPointEx(new HandleRef(null, Handle), pt.X, pt.Y, value);

            // Security Reviewed
            // While doing a security review it was noticed that GetChildAtPoint 
            // does work to ensure that you can only gain access to children of your own control,
            // but the methods it uses to determine the children demand all window permission first, 
            // negating the extra check. 
            // It is OK to return child windows for children within your own control for semitrust.
 
            // Hence  calling the Internal methods to ByPass the Security Demand...
            // for IntSecurity.ControlFromHandleOrLocation == ALLWindows.

            Control ctl = FromChildHandleInternal(hwnd); 
            if (ctl != null && !IsDescendant(ctl)) {
                Debug.WriteLineIf(IntSecurity.SecurityDemand.TraceVerbose, "ControlFromHandleOrLocation Demanded"); 
                IntSecurity.ControlFromHandleOrLocation.Demand(); 
            }
 
            return(ctl == this) ? null : ctl;
        }

 
        /// 
        ///  
        ///     Retrieves the child control that is located at the specified client 
        ///     coordinates.
        ///  
        public Control GetChildAtPoint(Point pt) {
            return GetChildAtPoint(pt, GetChildAtPointSkip.None);
        }
 
        /// 
        ///  
        ///     Returns the closest ContainerControl in the control's chain of 
        ///     parent controls and forms.
        ///  
        public IContainerControl GetContainerControl() {
            Debug.WriteLineIf(IntSecurity.SecurityDemand.TraceVerbose, "GetParent Demanded");
            IntSecurity.GetParent.Demand();
            return GetContainerControlInternal(); 
        }
 
        private static bool IsFocusManagingContainerControl(Control ctl) { 
            return ((ctl.controlStyle & ControlStyles.ContainerControl) == ControlStyles.ContainerControl && ctl is IContainerControl);
        } 

    /// 
        ///     This new Internal method checks the updateCount to signify that the control is within the "BeginUpdate" and "EndUpdate" cycle.
        ///     Check out Vs whidbey : 310110 : for usage of this. The Treeview tries to ForceUpdate the scrollbars by calling "WM_SETREDRAW" 
        ///     even if the control in "Begin - End" update cycle. Using thie Function we can guard against repetitively redrawing the control.
        ///  
        internal bool IsUpdating() 
        {
            return (updateCount > 0); 
        }

        // SECURITY WARNING: This method bypasses a security demand. Use with caution!
        internal IContainerControl GetContainerControlInternal() { 
            Control c = this;
 
            // VsWhidbey 434959 : Refer to IsContainerControl property for more details. 
            if (c != null && IsContainerControl)
            { 
                c = c.ParentInternal;
            }
            while (c != null && (!IsFocusManagingContainerControl(c))) {
                c = c.ParentInternal; 
            }
            return (IContainerControl)c; 
        } 

        // Essentially an Hfont; see inner class for details. 
        private static FontHandleWrapper GetDefaultFontHandleWrapper() {
            if (defaultFontHandleWrapper == null) {
                defaultFontHandleWrapper = new FontHandleWrapper(DefaultFont);
            } 

            return defaultFontHandleWrapper; 
        } 

        internal IntPtr GetHRgn(Region region) { 
            Graphics graphics = CreateGraphicsInternal();
            IntPtr handle = region.GetHrgn(graphics);
            System.Internal.HandleCollector.Add(handle, NativeMethods.CommonHandles.GDI);
            graphics.Dispose(); 
            return handle;
        } 
 
        /// 
        ///  
        ///     This is a helper method that is called by ScaleControl to retrieve the bounds
        ///     that the control should be scaled by.  You may override this method if you
        ///     wish to reuse ScaleControl's scaling logic but you need to supply your own
        ///     bounds.  The default implementation returns scaled bounds that take into 
        ///     account the BoundsSpecified, whether the control is top level, and whether
        ///     the control is fixed width or auto size, and any adornments the control may have. 
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual Rectangle GetScaledBounds(Rectangle bounds, SizeF factor, BoundsSpecified specified) { 

            // We should not include the window adornments in our calculation,
            // because windows scales them for us.
            NativeMethods.RECT adornments = new NativeMethods.RECT(0, 0, 0, 0); 
            CreateParams cp = CreateParams;
            SafeNativeMethods.AdjustWindowRectEx(ref adornments, cp.Style, HasMenu, cp.ExStyle); 
 
            float dx = factor.Width;
            float dy = factor.Height; 

            int sx = bounds.X;
            int sy = bounds.Y;
 
            // Don't reposition top level controls.  Also, if we're in
            // design mode, don't reposition the root component. 
            bool scaleLoc = !GetState(STATE_TOPLEVEL); 
            if (scaleLoc) {
                ISite site = Site; 
                if (site != null && site.DesignMode) {
                    IDesignerHost host = site.GetService(typeof(IDesignerHost)) as IDesignerHost;
                    if (host != null && host.RootComponent == this) {
                        scaleLoc = false; 
                    }
                } 
            } 

            if (scaleLoc) { 
                if ((specified & BoundsSpecified.X) != 0) {
                    sx = (int)Math.Round(bounds.X * dx);
                }
 
                if ((specified & BoundsSpecified.Y) != 0) {
                    sy = (int)Math.Round(bounds.Y * dy); 
                } 
            }
 
            int sw = bounds.Width;
            int sh = bounds.Height;

            // Do this even for auto sized controls.  They'll "snap back", but it is important to size them in case 
            // they are anchored.
            if ((controlStyle & ControlStyles.FixedWidth) != ControlStyles.FixedWidth && (specified & BoundsSpecified.Width) != 0) { 
                int adornmentWidth = (adornments.right - adornments.left); 
                int localWidth = bounds.Width - adornmentWidth;
                sw = (int)Math.Round(localWidth * dx) + adornmentWidth; 
            }
            if ((controlStyle & ControlStyles.FixedHeight) != ControlStyles.FixedHeight && (specified & BoundsSpecified.Height) != 0) {
                int adornmentHeight = (adornments.bottom - adornments.top);
                int localHeight = bounds.Height - adornmentHeight; 
                sh = (int)Math.Round(localHeight * dy) + adornmentHeight;
            } 
 
            return new Rectangle(sx, sy, sw, sh);
        } 

        private MouseButtons GetXButton(int wparam) {
            switch (wparam) {
            case NativeMethods.XBUTTON1: 
                return MouseButtons.XButton1;
            case NativeMethods.XBUTTON2: 
                return MouseButtons.XButton2; 
            }
            Debug.Fail("Unknown XButton: " + wparam); 
            return MouseButtons.None;
        }

        internal virtual bool GetVisibleCore() { 
            // We are only visible if our parent is visible
            if (!GetState(STATE_VISIBLE)) 
                return false; 
            else if (ParentInternal == null)
                return true; 
            else
                return ParentInternal.GetVisibleCore();
        }
 
        internal bool GetAnyDisposingInHierarchy() {
            Control up = this; 
            bool isDisposing = false; 
            while (up != null) {
                if (up.Disposing) { 
                    isDisposing = true;
                    break;
                }
                up = up.parent; 
            }
            return isDisposing; 
        } 

        private MenuItem GetMenuItemFromHandleId(IntPtr hmenu, int item) { 
            MenuItem mi = null;
            int id = UnsafeNativeMethods.GetMenuItemID(new HandleRef(null, hmenu), item);
            if (id == unchecked((int)0xFFFFFFFF)) {
                IntPtr childMenu = IntPtr.Zero; 
                childMenu = UnsafeNativeMethods.GetSubMenu(new HandleRef(null, hmenu), item);
                int count = UnsafeNativeMethods.GetMenuItemCount(new HandleRef(null, childMenu)); 
                MenuItem found = null; 
                for (int i=0; i 
        ///     - Returns child controls sorted according to their TabIndex property order.
        ///     - Controls with the same TabIndex remain in original relative child index order (= z-order). 
        ///     - Returns a TabIndex sorted array of ControlTabOrderHolder objects.
        /// 
        private ArrayList GetChildControlsTabOrderList(bool handleCreatedOnly) {
            ArrayList holders = new ArrayList(); 

            foreach (Control c in Controls) { 
                if (!handleCreatedOnly || c.IsHandleCreated) { 
                    holders.Add(new ControlTabOrderHolder(holders.Count, c.TabIndex, c));
                } 
            }

            holders.Sort(new ControlTabOrderComparer());
 
            return holders;
        } 
 
        /// 
        ///     - Returns native child windows sorted according to their TabIndex property order. 
        ///     - Controls with the same TabIndex remain in original relative child index order (= z-order).
        ///     - Child windows with no corresponding Control objects (and therefore no discernable TabIndex)
        ///       are sorted to the front of the list (but remain in relative z-order to one another).
        ///     - This version returns a sorted array of integers, representing the original z-order 
        ///       based indexes of the native child windows.
        ///  
        private int[] GetChildWindowsInTabOrder() { 
            ArrayList holders = GetChildWindowsTabOrderList();
 
            int[] indexes = new int[holders.Count];

            for (int i = 0; i < holders.Count; i++) {
                indexes[i] = ((ControlTabOrderHolder) holders[i]).oldOrder; 
            }
 
            return indexes; 
        }
 
        /// 
        ///     - Returns child controls sorted according to their TabIndex property order.
        ///     - Controls with the same TabIndex remain in original relative child index order (= z-order).
        ///     - This version returns a sorted array of control references. 
        /// 
        internal Control[] GetChildControlsInTabOrder(bool handleCreatedOnly) { 
            ArrayList holders = GetChildControlsTabOrderList(handleCreatedOnly); 

            Control[] ctls = new Control[holders.Count]; 

            for (int i = 0; i < holders.Count; i++) {
                ctls[i] = ((ControlTabOrderHolder) holders[i]).control;
            } 

            return ctls; 
        } 

        ///  
        ///      This class contains a control and associates it with a z-order.
        ///      This is used when sorting controls based on tab index first,
        ///      z-order second.
        ///  
        private class ControlTabOrderHolder {
            internal readonly int oldOrder; 
            internal readonly int newOrder; 
            internal readonly Control control;
 
            internal ControlTabOrderHolder(int oldOrder, int newOrder, Control control) {
                this.oldOrder = oldOrder;
                this.newOrder = newOrder;
                this.control  = control; 
            }
        } 
 
        /// 
        ///      Used to sort controls based on tab index and z-order. 
        /// 
        private class ControlTabOrderComparer : IComparer {
            int IComparer.Compare(Object x, Object y) {
                ControlTabOrderHolder hx = (ControlTabOrderHolder) x; 
                ControlTabOrderHolder hy = (ControlTabOrderHolder) y;
 
                int delta = hx.newOrder - hy.newOrder; 
                if (delta == 0)
                    delta = hx.oldOrder - hy.oldOrder; 

                return delta;
            }
        } 

        ///  
        ///     Given a native window handle, returns array of handles to window's children (in z-order). 
        /// 
        private static ArrayList GetChildWindows(IntPtr hWndParent) { 
            ArrayList windows = new ArrayList();

            for (IntPtr hWndChild = UnsafeNativeMethods.GetWindow(new HandleRef(null, hWndParent), NativeMethods.GW_CHILD);
                 hWndChild != IntPtr.Zero; 
                 hWndChild = UnsafeNativeMethods.GetWindow(new HandleRef(null, hWndChild), NativeMethods.GW_HWNDNEXT)) {
                windows.Add(hWndChild); 
            } 

            return windows; 
        }

        /// 
        ///     - Returns native child windows sorted according to their TabIndex property order. 
        ///     - Controls with the same TabIndex remain in original relative child index order (= z-order).
        ///     - Child windows with no corresponding Control objects (and therefore no discernable TabIndex) 
        ///       are sorted to the front of the list (but remain in relative z-order to one another). 
        ///     - Returns a TabIndex sorted array of ControlTabOrderHolder objects.
        ///  
        private ArrayList GetChildWindowsTabOrderList() {
            ArrayList holders = new ArrayList();
            ArrayList windows = GetChildWindows(this.Handle);
 
            foreach (IntPtr hWnd in windows) {
                Control ctl = FromHandleInternal(hWnd); 
                int tabIndex = (ctl == null) ? -1 : ctl.TabIndex; 
                holders.Add(new ControlTabOrderHolder(holders.Count, tabIndex, ctl));
            } 

            holders.Sort(new ControlTabOrderComparer());

            return holders; 
        }
 
        // 

        internal virtual Control GetFirstChildControlInTabOrder(bool forward) { 

            ControlCollection ctlControls = (ControlCollection)this.Properties.GetObject(PropControlsCollection);

            Control found = null; 
            if (ctlControls != null) {
                 if (forward) { 
                    for (int c = 0; c < ctlControls.Count; c++) { 
                        if (found == null || found.tabIndex > ctlControls[c].tabIndex) {
                            found = ctlControls[c]; 
                        }
                    }
                 }
                 else { 

                    // Cycle through the controls in reverse z-order looking for the one with the highest 
                    // tab index. 
                    //
                    for (int c = ctlControls.Count - 1; c >= 0; c--) { 
                        if (found == null || found.tabIndex < ctlControls[c].tabIndex) {
                            found = ctlControls[c];
                        }
                    } 
                 }
            } 
            return found; 

        } 

        /// 
        /// 
        ///     Retrieves the next control in the tab order of child controls. 
        /// 
        public Control GetNextControl(Control ctl, bool forward) { 
            if (!Contains(ctl)) { 
                ctl = this;
            } 

            if (forward) {
                ControlCollection ctlControls = (ControlCollection)ctl.Properties.GetObject(PropControlsCollection);
 
                if (ctlControls != null && ctlControls.Count > 0 && (ctl == this || !IsFocusManagingContainerControl(ctl))) {
                    Control found = ctl.GetFirstChildControlInTabOrder(/*forward=*/true); 
                    if (found != null) { 
                        return found;
                    } 
                }

                while (ctl != this) {
                    int targetIndex = ctl.tabIndex; 
                    bool hitCtl = false;
                    Control found = null; 
                    Control p = ctl.parent; 

                    // Cycle through the controls in z-order looking for the one with the next highest 
                    // tab index.  Because there can be dups, we have to start with the existing tab index and
                    // remember to exclude the current control.
                    //
                    int parentControlCount = 0; 

                    ControlCollection parentControls = (ControlCollection)p.Properties.GetObject(PropControlsCollection); 
 
                    if (parentControls != null) {
                        parentControlCount = parentControls.Count; 
                    }

                    for (int c = 0; c < parentControlCount; c++) {
 
                        // The logic for this is a bit lengthy, so I have broken it into separate
                        // caluses: 
 
                        // We are not interested in ourself.
                        // 
                        if (parentControls[c] != ctl) {

                            // We are interested in controls with >= tab indexes to ctl.  We must include those
                            // controls with equal indexes to account for duplicate indexes. 
                            //
                            if (parentControls[c].tabIndex >= targetIndex) { 
 
                                // Check to see if this control replaces the "best match" we've already
                                // found. 
                                //
                                if (found == null || found.tabIndex > parentControls[c].tabIndex) {

                                    // Finally, check to make sure that if this tab index is the same as ctl, 
                                    // that we've already encountered ctl in the z-order.  If it isn't the same,
                                    // than we're more than happy with it. 
                                    // 
                                    if (parentControls[c].tabIndex != targetIndex || hitCtl) {
                                        found = parentControls[c]; 
                                    }
                                }
                            }
                        } 
                        else {
                            // We track when we have encountered "ctl".  We never want to select ctl again, but 
                            // we want to know when we've seen it in case we find another control with the same tab index. 
                            //
                            hitCtl = true; 
                        }
                    }

                    if (found != null) { 
                        return found;
                    } 
 
                    ctl = ctl.parent;
                } 
            }
            else {
                if (ctl != this) {
 
                    int targetIndex = ctl.tabIndex;
                    bool hitCtl = false; 
                    Control found = null; 
                    Control p = ctl.parent;
 
                    // Cycle through the controls in reverse z-order looking for the next lowest tab index.  We must
                    // start with the same tab index as ctl, because there can be dups.
                    //
                    int parentControlCount = 0; 

                    ControlCollection parentControls = (ControlCollection)p.Properties.GetObject(PropControlsCollection); 
 
                    if (parentControls != null) {
                        parentControlCount = parentControls.Count; 
                    }

                    for (int c = parentControlCount - 1; c >= 0; c--) {
 
                        // The logic for this is a bit lengthy, so I have broken it into separate
                        // caluses: 
 
                        // We are not interested in ourself.
                        // 
                        if (parentControls[c] != ctl) {

                            // We are interested in controls with <= tab indexes to ctl.  We must include those
                            // controls with equal indexes to account for duplicate indexes. 
                            //
                            if (parentControls[c].tabIndex <= targetIndex) { 
 
                                // Check to see if this control replaces the "best match" we've already
                                // found. 
                                //
                                if (found == null || found.tabIndex < parentControls[c].tabIndex) {

                                    // Finally, check to make sure that if this tab index is the same as ctl, 
                                    // that we've already encountered ctl in the z-order.  If it isn't the same,
                                    // than we're more than happy with it. 
                                    // 
                                    if (parentControls[c].tabIndex != targetIndex || hitCtl) {
                                        found = parentControls[c]; 
                                    }
                                }
                            }
                        } 
                        else {
                            // We track when we have encountered "ctl".  We never want to select ctl again, but 
                            // we want to know when we've seen it in case we find another control with the same tab index. 
                            //
                            hitCtl = true; 
                        }
                    }

                    // If we were unable to find a control we should return the control's parent.  However, if that parent is us, return 
                    // NULL.
                    // 
                    if (found != null) { 
                        ctl = found;
                    } 
                    else {
                        if (p == this) {
                            return null;
                        } 
                        else {
                            return p; 
                        } 
                    }
                } 

                // We found a control.  Walk into this control to find the proper sub control within it to select.
                //
                ControlCollection ctlControls = (ControlCollection)ctl.Properties.GetObject(PropControlsCollection); 

                while (ctlControls != null && ctlControls.Count > 0 && (ctl == this || !IsFocusManagingContainerControl(ctl))) { 
                    Control found = ctl.GetFirstChildControlInTabOrder(/*forward=*/false); 
                    if (found != null) {
                        ctl = found; 
                        ctlControls = (ControlCollection)ctl.Properties.GetObject(PropControlsCollection);
                    }
                    else {
                        break; 
                    }
                } 
            } 

            return ctl == this? null: ctl; 
        }

        /// 
        ///     Return ((Control) window).Handle if window is a Control. 
        ///     Otherwise, demands permission for AllWindows and returns window.Handle
        ///  
        internal static IntPtr GetSafeHandle(IWin32Window window) 
        {
            Debug.Assert(window != null, "window is null in Control.GetSafeHandle"); 
            IntPtr hWnd = IntPtr.Zero;
            Control control = window as Control;
            if (control != null) {
                hWnd = control.Handle; 
                Debug.Assert(hWnd == IntPtr.Zero || UnsafeNativeMethods.IsWindow(new HandleRef(null, hWnd)));
                return hWnd; 
            } 
            else {
                IntSecurity.AllWindows.Demand(); 
                hWnd = window.Handle;
                if (hWnd == IntPtr.Zero || UnsafeNativeMethods.IsWindow(new HandleRef(null, hWnd))) {
                    return hWnd;
                } 
                else {
                    throw new Win32Exception(NativeMethods.ERROR_INVALID_HANDLE); 
                } 
            }
        } 

        /// 
        ///     Retrieves the current value of the specified bit in the control's state.
        ///  
        internal bool GetState(int flag) {
            return(state & flag) != 0; 
        } 

        ///  
        ///     Retrieves the current value of the specified bit in the control's state2.
        /// 
        private bool GetState2(int flag)
        { 
            return (state2 & flag) != 0;
        } 
 
        /// 
        ///  
        ///     Retrieves the current value of the specified bit in the control's style.
        ///     NOTE: This is control style, not the Win32 style of the hWnd.
        /// 
        protected bool GetStyle(ControlStyles flag) { 
            return (controlStyle & flag) == flag;
        } 
 
        /// 
        ///  
        ///     Hides the control by setting the visible property to false;
        /// 
        public void Hide() {
            Visible = false; 
        }
 
 
        /// 
        ///     Sets up the TrackMouseEvent for listening for the 
        ///     mouse leave event.
        /// 
        /// 
        private void HookMouseEvent() { 
            if (!GetState(STATE_TRACKINGMOUSEEVENT)) {
                SetState(STATE_TRACKINGMOUSEEVENT, true); 
 
                if (trackMouseEvent == null) {
                    trackMouseEvent = new NativeMethods.TRACKMOUSEEVENT(); 
                    trackMouseEvent.dwFlags = NativeMethods.TME_LEAVE | NativeMethods.TME_HOVER;
                    trackMouseEvent.hwndTrack = Handle;
                }
 
                SafeNativeMethods.TrackMouseEvent(trackMouseEvent);
            } 
        } 

        ///  
        /// 
        ///     Called after the control has been added to another container.
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual void InitLayout() {
            LayoutEngine.InitLayout(this, BoundsSpecified.All); 
        } 

        ///  
        ///     This method initializes the scaling bits for this control based on
        ///     the bounds.
        /// 
        private void InitScaling(BoundsSpecified specified) { 
            requiredScaling |= (byte)((int)specified & RequiredScalingMask);
        } 
 
        // Sets the text and background colors of the DC, and returns the background HBRUSH.
        // This gets called from some variation on WM_CTLCOLOR... 
        // Virtual because Scrollbar insists on being different.
        //
        // NOTE: this message may not have originally been sent to this HWND.
        // 

        [ResourceExposure(ResourceScope.None)] 
        [ResourceConsumption(ResourceScope.Process, ResourceScope.Process)] 
        internal virtual IntPtr InitializeDCForWmCtlColor (IntPtr dc, int msg) {
            if (!GetStyle(ControlStyles.UserPaint)) { 
                SafeNativeMethods.SetTextColor(new HandleRef(null, dc), ColorTranslator.ToWin32(ForeColor));
                SafeNativeMethods.SetBkColor(new HandleRef(null, dc), ColorTranslator.ToWin32(BackColor));
                return BackColorBrush;
            } 
            else {
                return UnsafeNativeMethods.GetStockObject(NativeMethods.HOLLOW_BRUSH); 
            } 
        }
 
        #if WIN95_SUPPORT
        /// 
        ///     Initializes mouse wheel support. This may involve registering some windows
        ///     messages on older operating systems. 
        /// 
        ///  
        private void InitMouseWheelSupport() { 
            if (!mouseWheelInit) {
                // If we are running on less than NT4 or less that Win98 then we must use 
                // the manual mousewheel stuff...
                //
                mouseWheelRoutingNeeded = !SystemInformation.NativeMouseWheelSupport;
 
                if (mouseWheelRoutingNeeded) {
                    IntPtr hwndMouseWheel = IntPtr.Zero; 
 
                    // Check for the MouseZ "service". This is a little app that generated the
                    // MSH_MOUSEWHEEL messages by monitoring the hardware. If this app isn't 
                    // found, then there is no support for MouseWheels on the system.
                    //
                    hwndMouseWheel = UnsafeNativeMethods.FindWindow(NativeMethods.MOUSEZ_CLASSNAME, NativeMethods.MOUSEZ_TITLE);
 
                    if (hwndMouseWheel != IntPtr.Zero) {
 
                        // Register the MSH_MOUSEWHEEL message... we look for this in the 
                        // wndProc, and treat it just like WM_MOUSEWHEEL.
                        // 
                        int message = SafeNativeMethods.RegisterWindowMessage(NativeMethods.MSH_MOUSEWHEEL);

                        if (message != 0) {
                            mouseWheelMessage = message; 
                        }
                    } 
                } 
                mouseWheelInit = true;
            } 
        }
        #endif

        ///  
        /// 
        ///     Invalidates a region of the control and causes a paint message 
        ///     to be sent to the control. This will not force a synchronous paint to 
        ///     occur, calling update after invalidate will force a
        ///     synchronous paint. 
        /// 
        public void Invalidate(Region region) {
            Invalidate(region, false);
        } 

        ///  
        ///  
        ///     Invalidates a region of the control and causes a paint message
        ///     to be sent to the control. This will not force a synchronous paint to 
        ///     occur, calling update after invalidate will force a
        ///     synchronous paint.
        /// 
        public void Invalidate(Region region, bool invalidateChildren) { 
            if (region == null) {
                Invalidate(invalidateChildren); 
            } 
            else if (IsHandleCreated) {
                IntPtr regionHandle = GetHRgn(region); 

                try {
                    Debug.Assert(regionHandle != IntPtr.Zero, "Region wasn't null but HRGN is?");
                    if (invalidateChildren) { 
                        SafeNativeMethods.RedrawWindow(new HandleRef(this, Handle),
                                                       null, new HandleRef(region, regionHandle), 
                                                       NativeMethods.RDW_INVALIDATE | 
                                                       NativeMethods.RDW_ERASE |
                                                       NativeMethods.RDW_ALLCHILDREN); 
                    }
                    else {
                        // It's safe to invoke InvalidateRgn from a separate thread.
                        using (new MultithreadSafeCallScope()) 
                        {
                            SafeNativeMethods.InvalidateRgn(new HandleRef(this, Handle), 
                                                            new HandleRef(region, regionHandle), 
                                                            !GetStyle(ControlStyles.Opaque));
                        } 
                    }
                }
                finally {
                    SafeNativeMethods.DeleteObject(new HandleRef(region, regionHandle)); 
                }
 
                Rectangle bounds = Rectangle.Empty; 

                // gpr: We shouldn't have to create a Graphics for this... 
                using (Graphics graphics = CreateGraphicsInternal()) {
                    bounds = Rectangle.Ceiling(region.GetBounds(graphics));
                }
 
                OnInvalidated(new InvalidateEventArgs(bounds));
            } 
        } 

 
        /// 
        /// 
        ///     Invalidates the control and causes a paint message to be sent to the control.
        ///     This will not force a synchronous paint to occur, calling update after 
        ///     invalidate will force a synchronous paint.
        ///  
        public void Invalidate() { 
            Invalidate(false);
        } 

        /// 
        /// 
        ///     Invalidates the control and causes a paint message to be sent to the control. 
        ///     This will not force a synchronous paint to occur, calling update after
        ///     invalidate will force a synchronous paint. 
        ///  
        public void Invalidate(bool invalidateChildren) {
            if (IsHandleCreated) { 
                if (invalidateChildren) {
                    SafeNativeMethods.RedrawWindow(new HandleRef(window, Handle),
                                                   null, NativeMethods.NullHandleRef,
                                                   NativeMethods.RDW_INVALIDATE | 
                                                   NativeMethods.RDW_ERASE |
                                                   NativeMethods.RDW_ALLCHILDREN); 
                } 
                else {
                    // It's safe to invoke InvalidateRect from a separate thread. 
                    using (new MultithreadSafeCallScope())
                    {
                        SafeNativeMethods.InvalidateRect(new HandleRef(window, Handle),
                                                         null, 
                                                         (controlStyle & ControlStyles.Opaque) != ControlStyles.Opaque);
                    } 
                } 

                NotifyInvalidate(this.ClientRectangle); 
            }
        }

        ///  
        /// 
        ///     Invalidates a rectangular region of the control and causes a paint message 
        ///     to be sent to the control. This will not force a synchronous paint to 
        ///     occur, calling update after invalidate will force a
        ///     synchronous paint. 
        /// 
        public void Invalidate(Rectangle rc) {
            Invalidate(rc, false);
        } 

        ///  
        ///  
        ///     Invalidates a rectangular region of the control and causes a paint message
        ///     to be sent to the control. This will not force a synchronous paint to 
        ///     occur, calling update after invalidate will force a
        ///     synchronous paint.
        /// 
        public void Invalidate(Rectangle rc, bool invalidateChildren) { 
            if (rc.IsEmpty) {
                Invalidate(invalidateChildren); 
            } 
            else if (IsHandleCreated) {
                if (invalidateChildren) { 
                    NativeMethods.RECT rcArea = NativeMethods.RECT.FromXYWH(rc.X, rc.Y, rc.Width, rc.Height);
                    SafeNativeMethods.RedrawWindow(new HandleRef(window, Handle),
                                                   ref rcArea, NativeMethods.NullHandleRef,
                                                   NativeMethods.RDW_INVALIDATE | 
                                                   NativeMethods.RDW_ERASE |
                                                   NativeMethods.RDW_ALLCHILDREN); 
                } 
                else {
                    NativeMethods.RECT rcArea = 
                        NativeMethods.RECT.FromXYWH(rc.X, rc.Y, rc.Width,
                                                    rc.Height);

                    // It's safe to invoke InvalidateRect from a separate thread. 
                    using (new MultithreadSafeCallScope())
                    { 
                        SafeNativeMethods.InvalidateRect(new HandleRef(window, Handle), 
                                                         ref rcArea,
                                                         (controlStyle & ControlStyles.Opaque) != ControlStyles.Opaque); 
                    }
                }
                NotifyInvalidate(rc);
            } 
        }
        ///  
        ///  
        ///     Executes the given delegate on the thread that owns this Control's
        ///     underlying window handle.  It is an error to call this on the same thread that 
        ///     the control belongs to.  If the control's handle doesn't exist yet, this will
        ///     follow up the control's parent chain until it finds a control or form that does
        ///     have a window handle.  If no appropriate handle can be found, invoke will throw
        ///     an exception.  Exceptions that are raised during the call will be 
        ///     propapgated back to the caller.
        /// 
        ///     There are five functions on a control that are safe to call from any 
        ///     thread:  GetInvokeRequired, Invoke, BeginInvoke, EndInvoke and CreateGraphics.
        ///     For all other metohd calls, you should use one of the invoke methods to marshal 
        ///     the call to the control's thread.
        /// 
        public Object Invoke(Delegate method) {
            return Invoke(method, null); 
        }
 
        ///  
        /// 
        ///     Executes the given delegate on the thread that owns this Control's 
        ///     underlying window handle.  It is an error to call this on the same thread that
        ///     the control belongs to.  If the control's handle doesn't exist yet, this will
        ///     follow up the control's parent chain until it finds a control or form that does
        ///     have a window handle.  If no appropriate handle can be found, invoke will throw 
        ///     an exception.  Exceptions that are raised during the call will be
        ///     propapgated back to the caller. 
        /// 
        ///     There are five functions on a control that are safe to call from any
        ///     thread:  GetInvokeRequired, Invoke, BeginInvoke, EndInvoke and CreateGraphics. 
        ///     For all other metohd calls, you should use one of the invoke methods to marshal
        ///     the call to the control's thread.
        /// 
        public Object Invoke(Delegate method, params Object[] args) { 
            using (new MultithreadSafeCallScope()) {
                Control marshaler = FindMarshalingControl(); 
                return marshaler.MarshaledInvoke(this, method, args, true); 
            }
        } 

        /// 
        ///     Perform the callback of a particular ThreadMethodEntry - called by InvokeMarshaledCallbacks below.
        /// 
        ///     If the invoke request originated from another thread, we should have already captured the ExecutionContext
        ///     of that thread. The callback is then invoked using that ExecutionContext (which includes info like the 
        ///     compressed security stack). 
        ///
        ///     NOTE: The one part of the ExecutionContext that we DONT want applied to the callback is its SyncContext, 
        ///     since this is the SyncContext of the other thread. So we grab the SyncContext of OUR thread, and pass
        ///     this through to the callback to use instead.
        ///
        ///     When the invoke request comes from this thread, there won't be an ExecutionContext so we just invoke 
        ///     the callback as is.
        ///  
        private void InvokeMarshaledCallback(ThreadMethodEntry tme){ 
            if (tme.executionContext != null) {
                if (invokeMarshaledCallbackHelperDelegate == null) { 
                    invokeMarshaledCallbackHelperDelegate = new ContextCallback(InvokeMarshaledCallbackHelper);
                }
                // If there's no ExecutionContext, make sure we have a SynchronizationContext.  There's no
                // direct check for ExecutionContext: this is as close as we can get. 
                if (SynchronizationContext.Current == null) {
                    WindowsFormsSynchronizationContext.InstallIfNeeded(); 
                } 

                tme.syncContext = SynchronizationContext.Current; 
                ExecutionContext.Run(tme.executionContext, invokeMarshaledCallbackHelperDelegate, tme);
            }
            else {
                InvokeMarshaledCallbackHelper(tme); 
            }
        } 
 
        /// 
        ///     Worker for invoking marshaled callbacks. 
        /// 
        private static void InvokeMarshaledCallbackHelper(object obj)
        {
            ThreadMethodEntry tme = (ThreadMethodEntry) obj; 

            if (tme.syncContext != null) { 
                SynchronizationContext oldContext = SynchronizationContext.Current; 

                try { 
                    SynchronizationContext.SetSynchronizationContext(tme.syncContext);

                    InvokeMarshaledCallbackDo(tme);
                } 
                finally {
                    SynchronizationContext.SetSynchronizationContext(oldContext); 
                } 
            }
            else { 
                InvokeMarshaledCallbackDo(tme);
            }
        }
 
        /// 
        ///  
        private static void InvokeMarshaledCallbackDo(ThreadMethodEntry tme) 
        {
            // We short-circuit a couple of common cases for speed. 
            //
            if (tme.method is EventHandler) {
                if (tme.args == null || tme.args.Length < 1) {
                    ((EventHandler)tme.method)(tme.caller, EventArgs.Empty); 
                }
                else if (tme.args.Length < 2) { 
                    ((EventHandler)tme.method)(tme.args[0], EventArgs.Empty); 
                }
                else { 
                    ((EventHandler)tme.method)(tme.args[0], (EventArgs)tme.args[1]);
                }
            }
            else if (tme.method is MethodInvoker) { 
                ((MethodInvoker)tme.method)();
            } 
            else if (tme.method is WaitCallback) 
            {
                Debug.Assert(tme.args.Length == 1, 
                             "Arguments are wrong for WaitCallback");
                ((WaitCallback)tme.method)(tme.args[0]);
            }
            else { 
                tme.retVal = tme.method.DynamicInvoke(tme.args);
            } 
        } 

        ///  
        ///     Called on the control's owning thread to perform the actual callback.
        ///     This empties this control's callback queue, propagating any exceptions
        ///     back as needed.
        ///  
        private void InvokeMarshaledCallbacks() {
            ThreadMethodEntry current = null; 
            lock(threadCallbackList) { 
                if (threadCallbackList.Count > 0) {
                    current = (ThreadMethodEntry)threadCallbackList.Dequeue(); 
                }
            }

            // Now invoke on all the queued items. 
            //
            while (current != null) { 
                if (current.method != null) { 

                    try { 
                        // If we are running under the debugger, don't wrap asynchronous
                        // calls in a try catch.  It is much better to throw here than pop up
                        // a thread exception dialog below.
                        if (NativeWindow.WndProcShouldBeDebuggable  && !current.synchronous) { 
                            InvokeMarshaledCallback(current);
                        } 
                        else { 
                            try {
                                InvokeMarshaledCallback(current); 
                            }
                            catch (Exception t) {
                                current.exception = t.GetBaseException();
                            } 
                        }
                    } 
                    finally { 
                        current.Complete();
 
                        // This code matches the behavior above.  Basically, if we're debugging, don't
                        // do this because the exception would have been handled above.  If we're
                        // not debugging, raise the exception here.
                        if (!NativeWindow.WndProcShouldBeDebuggable && 
                            current.exception != null && !current.synchronous) {
                            Application.OnThreadException(current.exception); 
                        } 
                    }
                } 

                lock (threadCallbackList) {
                    if (threadCallbackList.Count > 0) {
                        current = (ThreadMethodEntry)threadCallbackList.Dequeue(); 
                    }
                    else { 
                        current = null; 
                    }
                } 
            }
        }

        ///  
        /// 
        ///    [To be supplied.] 
        ///  
        protected void InvokePaint(Control c, PaintEventArgs e) {
            c.OnPaint(e); 
        }

        /// 
        ///  
        ///    [To be supplied.]
        ///  
        protected void InvokePaintBackground(Control c, PaintEventArgs e) { 
           c.OnPaintBackground(e);
        } 

        /// 
        /// determines whether the font is set
        ///  
        /// 
        internal bool IsFontSet() { 
            Font font = (Font)Properties.GetObject(PropFont); 
            if (font != null) {
                return true; 
            }
            return false;
        }
 
        /// 
        ///     WARNING! The meaning of this method is not what it appears. 
        ///     The method returns true if "descendant" (the argument) is a descendant 
        ///     of "this". I'd expect it to be the other way around, but oh well too late.
        ///  
        /// 
        internal bool IsDescendant(Control descendant) {
            Control control = descendant;
            while (control != null) { 
                if (control == this)
                    return true; 
                control = control.ParentInternal; 
            }
            return false; 
        }

        /// 
        ///  
        /// This Function will return a Boolean as to whether the Key value passed in is Locked...
        ///  
        public static bool IsKeyLocked(Keys keyVal) { 
            if (keyVal == Keys.Insert || keyVal == Keys.NumLock || keyVal == Keys.CapsLock || keyVal == Keys.Scroll) {
                int result = UnsafeNativeMethods.GetKeyState((int)keyVal); 

                // If the high-order bit is 1, the key is down; otherwise, it is up.
                // If the low-order bit is 1, the key is toggled. A key, such as the CAPS LOCK key,
                // is toggled if it is turned on. The key is off and untoggled if the low-order bit is 0. 
                // A toggle key's indicator light (if any) on the keyboard will be on when the key is toggled,
                // and off when the key is untoggled. 
 
                // Toggle keys (only low bit is of interest).
                if( keyVal == Keys.Insert || keyVal == Keys.CapsLock ) 
                {
                    return (result & 0x1) != 0x0;
                }
 
                return (result & 0x8001) != 0x0;
            } 
 
            // else - it's an un-lockable key.
            // VSWhidbey 95660: Actually get the exception string from the system resource. 
            throw new NotSupportedException(SR.GetString(SR.ControlIsKeyLockedNumCapsScrollLockKeysSupportedOnly));
        }

        ///  
        /// 
        ///     Determines if charCode is an input character that the control 
        ///     wants. This method is called during window message pre-processing to 
        ///     determine whether the given input character should be pre-processed or
        ///     sent directly to the control. If isInputChar returns true, the 
        ///     given character is sent directly to the control. If isInputChar
        ///     returns false, the character is pre-processed and only sent to the
        ///     control if it is not consumed by the pre-processing phase. The
        ///     pre-processing of a character includes checking whether the character 
        ///     is a mnemonic of another control.
        ///  
 
        // SECREVIEW:
        // NOT LinkDemanding here because these functions do not have a processing side effect 
        // by directly calling them.
        [UIPermission(SecurityAction.InheritanceDemand, Window=UIPermissionWindow.AllWindows)]
        protected virtual bool IsInputChar(char charCode) {
            Debug.WriteLineIf(ControlKeyboardRouting.TraceVerbose, "Control.IsInputChar 0x" + ((int)charCode).ToString("X", CultureInfo.InvariantCulture)); 

            int mask = 0; 
            if (charCode == (char)(int)Keys.Tab) { 
                mask = NativeMethods.DLGC_WANTCHARS | NativeMethods.DLGC_WANTALLKEYS | NativeMethods.DLGC_WANTTAB;
            } 
            else {
                mask = NativeMethods.DLGC_WANTCHARS | NativeMethods.DLGC_WANTALLKEYS;
            }
            return(unchecked( (int) (long)SendMessage(NativeMethods.WM_GETDLGCODE, 0, 0)) & mask) != 0; 
        }
 
        ///  
        /// 
        ///     Determines if keyData is an input key that the control wants. 
        ///     This method is called during window message pre-processing to determine
        ///     whether the given input key should be pre-processed or sent directly to
        ///     the control. If isInputKey returns true, the given key is sent
        ///     directly to the control. If isInputKey returns false, the key is 
        ///     pre-processed and only sent to the control if it is not consumed by the
        ///     pre-processing phase. Keys that are pre-processed include TAB, RETURN, 
        ///     ESCAPE, and arrow keys. 
        /// 
 
        // SECREVIEW:
        // NOT LinkDemanding here because these functions do not have a processing side effect
        // by directly calling them.
        [UIPermission(SecurityAction.InheritanceDemand, Window=UIPermissionWindow.AllWindows)] 
        protected virtual bool IsInputKey(Keys keyData) {
            Debug.WriteLineIf(ControlKeyboardRouting.TraceVerbose, "Control.IsInputKey " + keyData.ToString()); 
 
            if ((keyData & Keys.Alt) == Keys.Alt) return false;
            int mask = NativeMethods.DLGC_WANTALLKEYS; 
            switch (keyData & Keys.KeyCode) {
                case Keys.Tab:
                    mask = NativeMethods.DLGC_WANTALLKEYS | NativeMethods.DLGC_WANTTAB;
                    break; 
                case Keys.Left:
                case Keys.Right: 
                case Keys.Up: 
                case Keys.Down:
                    mask = NativeMethods.DLGC_WANTALLKEYS | NativeMethods.DLGC_WANTARROWS; 
                    break;
            }

            if (IsHandleCreated) { 
                return(unchecked( (int) (long)SendMessage(NativeMethods.WM_GETDLGCODE, 0, 0)) & mask) != 0;
            } 
            else { 
                return false;
            } 
        }

        /// 
        ///  
        ///     Determines if charCode is the mnemonic character in text.
        ///     The mnemonic character is the character imediately following the first 
        ///     instance of "&" in text 
        /// 
        public static bool IsMnemonic(char charCode, string text) { 
#if DEBUG
            if (ControlKeyboardRouting.TraceVerbose) {
                Debug.Write("Control.IsMnemonic(" + charCode.ToString() + ", ");
 
                if (text != null) {
                    Debug.Write(text); 
                } 
                else {
                    Debug.Write("null"); 
                }
                Debug.WriteLine(")");
            }
#endif 

            //Special case handling: 
            if (charCode=='&') { 
                Debug.WriteLineIf(ControlKeyboardRouting.TraceVerbose, "   ...returning false");
                return false; 
            } //if


            if (text != null) { 
                int pos = -1; // start with -1 to handle double &'s
                char c2 = Char.ToUpper(charCode, CultureInfo.CurrentCulture); 
                for (;;) { 
                    if (pos + 1 >= text.Length)
                        break; 
                    pos = text.IndexOf('&', pos + 1) + 1;
                    if (pos <= 0 || pos >= text.Length)
                        break;
                    char c1 = Char.ToUpper(text[pos], CultureInfo.CurrentCulture); 
                    Debug.WriteLineIf(ControlKeyboardRouting.TraceVerbose, "   ...& found... char=" + c1.ToString());
                    if (c1 == c2 || Char.ToLower(c1, CultureInfo.CurrentCulture) == Char.ToLower(c2, CultureInfo.CurrentCulture)) { 
                        Debug.WriteLineIf(ControlKeyboardRouting.TraceVerbose, "   ...returning true"); 
                        return true;
                    } 
                }
                Debug.WriteLineIf(ControlKeyboardRouting.TraceVerbose && pos == 0, "   ...no & found");
            }
            Debug.WriteLineIf(ControlKeyboardRouting.TraceVerbose, "   ...returning false"); 
            return false;
        } 
 
        private void ListenToUserPreferenceChanged(bool listen) {
            if (GetState2(STATE2_LISTENINGTOUSERPREFERENCECHANGED)) { 
                if (!listen) {
                    SetState2(STATE2_LISTENINGTOUSERPREFERENCECHANGED, false);
                    SystemEvents.UserPreferenceChanged -= new UserPreferenceChangedEventHandler(this.UserPreferenceChanged);
                } 
            }
            else if (listen) { 
                SetState2(STATE2_LISTENINGTOUSERPREFERENCECHANGED, true); 
                SystemEvents.UserPreferenceChanged += new UserPreferenceChangedEventHandler(this.UserPreferenceChanged);
            } 
        }

        private Object MarshaledInvoke(Control caller, Delegate method, Object[] args, bool synchronous) {
 
            // Marshaling an invoke occurs in three steps:
            // 
            // 1.  Create a ThreadMethodEntry that contains the packet of information 
            //     about this invoke.  This TME is placed on a linked list of entries because
            //     we have a gap between the time we PostMessage and the time it actually 
            //     gets processed, and this gap may allow other invokes to come in.  Access
            //     to this linked list is always synchronized.
            //
            // 2.  Post ourselves a message.  Our caller has already determined the 
            //     best control to call us on, and we should almost always have a handle.
            // 
            // 3.  If we're synchronous, wait for the message to get processed.  We don't do 
            //     a SendMessage here so we're compatible with OLE, which will abort many
            //     types of calls if we're within a SendMessage. 
            //

            if (!IsHandleCreated) {
                throw new InvalidOperationException(SR.GetString(SR.ErrorNoMarshalingThread)); 
            }
 
            // We have to demand unmanaged code permission here for the control hosted in 
            // the browser case. Without this check, we will expose a security hole, because
            // ActiveXImpl.OnMessage() will assert unmanaged code for everyone as part of 
            // its implementation.
            // The right fix is to remove the Assert() on top of the ActiveXImpl class, and
            // visit each method to see if it needs unmanaged code permission, and if so, add
            // the permission just to that method(s). 
            //
            ActiveXImpl activeXImpl = (ActiveXImpl)Properties.GetObject(PropActiveXImpl); 
            if (activeXImpl != null) { 
                IntSecurity.UnmanagedCode.Demand();
            } 

            // We don't want to wait if we're on the same thread, or else we'll deadlock.
            // It is important that syncSameThread always be false for asynchronous calls.
            // 
            bool syncSameThread = false;
            int pid; // ignored 
            if (SafeNativeMethods.GetWindowThreadProcessId(new HandleRef(this, Handle), out pid) == SafeNativeMethods.GetCurrentThreadId()) { 
                if (synchronous)
                    syncSameThread = true; 
            }

            // Store the compressed stack information from the thread that is calling the Invoke()
            // so we can assign the same security context to the thread that will actually execute 
            // the delegate being passed.
            // 
            ExecutionContext executionContext = null; 
            if (!syncSameThread) {
                executionContext = ExecutionContext.Capture(); 
            }
            ThreadMethodEntry tme = new ThreadMethodEntry(caller, this, method, args, synchronous, executionContext);

            lock (this) { 
                if (threadCallbackList == null) {
                    threadCallbackList = new Queue(); 
                } 
            }
 
            lock (threadCallbackList) {
                if (threadCallbackMessage == 0) {
                    threadCallbackMessage = SafeNativeMethods.RegisterWindowMessage(Application.WindowMessagesVersion + "_ThreadCallbackMessage");
                } 
                threadCallbackList.Enqueue(tme);
            } 
 
            if (syncSameThread) {
                InvokeMarshaledCallbacks(); 
            }  else {
                //

                UnsafeNativeMethods.PostMessage(new HandleRef(this, Handle), threadCallbackMessage, IntPtr.Zero, IntPtr.Zero); 
            }
 
            if (synchronous) { 
                if (!tme.IsCompleted) {
                    WaitForWaitHandle(tme.AsyncWaitHandle); 
                }
                if (tme.exception != null) {
                    throw tme.exception;
                } 
                return tme.retVal;
            } 
            else { 
                return(IAsyncResult)tme;
            } 
        }

        /// 
        ///     This method is used by WM_GETCONTROLNAME and WM_GETCONTROLTYPE 
        ///     to marshal a string to a message structure.  It handles
        ///     two cases:  if no buffer was passed it returns the size of 
        ///     buffer needed.  If a buffer was passed, it fills the buffer. 
        ///     If the passed buffer is not long enough it will return -1.
        ///  
        private void MarshalStringToMessage(string value, ref Message m) {
            if (m.LParam == IntPtr.Zero) {
                m.Result = (IntPtr)((value.Length + 1) * Marshal.SystemDefaultCharSize);
                return; 
            }
 
            if (unchecked((int)(long)m.WParam) < value.Length + 1) { 
                m.Result = (IntPtr)(-1);
                return; 
            }

            // Copy the name into the given IntPtr
            // 
            char[] nullChar = new char[] {(char)0};
            byte[] nullBytes; 
            byte[] bytes; 

            if (Marshal.SystemDefaultCharSize == 1) { 
                bytes = Encoding.Default.GetBytes(value);
                nullBytes = Encoding.Default.GetBytes(nullChar);
            }
            else { 
                bytes = Encoding.Unicode.GetBytes(value);
                nullBytes = Encoding.Unicode.GetBytes(nullChar); 
            } 

            Marshal.Copy(bytes, 0, m.LParam, bytes.Length); 
            Marshal.Copy(nullBytes, 0, unchecked((IntPtr)((long)m.LParam + (long)bytes.Length)), nullBytes.Length);

            m.Result = (IntPtr)((bytes.Length + nullBytes.Length)/Marshal.SystemDefaultCharSize);
        } 

        // Used by form to notify the control that it has been "entered" 
        // 
        internal void NotifyEnter() {
            Debug.WriteLineIf(Control.FocusTracing.TraceVerbose, "Control::NotifyEnter() - " + this.Name); 
            OnEnter(EventArgs.Empty);
        }

        // Used by form to notify the control that it has been "left" 
        //
        internal void NotifyLeave() { 
            Debug.WriteLineIf(Control.FocusTracing.TraceVerbose, "Control::NotifyLeave() - " + this.Name); 
            OnLeave(EventArgs.Empty);
        } 


        /// 
        ///  
        /// 
        ///    Propagates the invalidation event, notifying the control that 
        ///    some part of it is being invalidated and will subsequently need 
        ///    to repaint.
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void NotifyInvalidate(Rectangle invalidatedArea) {
            OnInvalidated(new InvalidateEventArgs(invalidatedArea));
        } 

        // Used by form to notify the control that it is validating. 
        // 
        private bool NotifyValidating() {
            CancelEventArgs ev = new CancelEventArgs(); 
            OnValidating(ev);
            return ev.Cancel;
        }
 
        // Used by form to notify the control that it has been validated.
        // 
        private void NotifyValidated() { 
            OnValidated(EventArgs.Empty);
        } 

        /// 
        /// 
        /// Raises the  event. 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected void InvokeOnClick(Control toInvoke, EventArgs e) { 
            if (toInvoke != null) {
                toInvoke.OnClick(e); 
            }
        }

        ///  
        protected virtual void OnAutoSizeChanged(EventArgs e) {
            EventHandler eh = Events[EventAutoSizeChanged] as EventHandler; 
            if (eh != null) { 
                 eh(this, e);
            } 
        }

        /// 
        ///  
        ///    [To be supplied.]
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual void OnBackColorChanged(EventArgs e) {
            if (GetAnyDisposingInHierarchy()) { 
                return;
            }

            object backBrush = Properties.GetObject(PropBackBrush); 
            if (backBrush != null) {
                if (GetState(STATE_OWNCTLBRUSH)) { 
                    IntPtr p = (IntPtr)backBrush; 
                    if (p != IntPtr.Zero) {
                        SafeNativeMethods.DeleteObject(new HandleRef(this, p)); 
                    }
                }
                Properties.SetObject(PropBackBrush, null);
            } 

            Invalidate(); 
 
            EventHandler eh = Events[EventBackColor] as EventHandler;
            if (eh != null) { 
                 eh(this, e);
            }

            ControlCollection controlsCollection = (ControlCollection)Properties.GetObject(PropControlsCollection); 
            if (controlsCollection != null) {
                // PERFNOTE: This is more efficient than using Foreach.  Foreach 
                // forces the creation of an array subset enum each time we 
                // enumerate
                for(int i = 0; i < controlsCollection.Count; i++) { 
                    controlsCollection[i].OnParentBackColorChanged(e);
                }
            }
        } 

        ///  
        ///  
        ///    [To be supplied.]
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnBackgroundImageChanged(EventArgs e) {
            if (GetAnyDisposingInHierarchy()) {
                return; 
            }
 
            Invalidate(); 

            EventHandler eh = Events[EventBackgroundImage] as EventHandler; 
            if (eh != null) {
                 eh(this, e);
            }
 
            ControlCollection controlsCollection = (ControlCollection)Properties.GetObject(PropControlsCollection);
            if (controlsCollection != null) { 
                // PERFNOTE: This is more efficient than using Foreach.  Foreach 
                // forces the creation of an array subset enum each time we
                // enumerate 
                for(int i = 0; i < controlsCollection.Count; i++) {
                    controlsCollection[i].OnParentBackgroundImageChanged(e);
                }
            } 
        }
 
        ///  
        /// 
        ///    [To be supplied.] 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnBackgroundImageLayoutChanged(EventArgs e) {
            if (GetAnyDisposingInHierarchy()) { 
                return;
            } 
 
            Invalidate();
 
            EventHandler eh = Events[EventBackgroundImageLayout] as EventHandler;
            if (eh != null) {
                 eh(this, e);
            } 
        }
 
        ///  
        /// 
        ///    [To be supplied.] 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnBindingContextChanged(EventArgs e) {
            if (Properties.GetObject(PropBindings) != null) { 
                UpdateBindings();
            } 
 
            EventHandler eh = Events[EventBindingContext] as EventHandler;
            if (eh != null) { 
                 eh(this, e);
            }

            ControlCollection controlsCollection = (ControlCollection)Properties.GetObject(PropControlsCollection); 
            if (controlsCollection != null) {
                // PERFNOTE: This is more efficient than using Foreach.  Foreach 
                // forces the creation of an array subset enum each time we 
                // enumerate
                for(int i = 0; i < controlsCollection.Count; i++) { 
                    controlsCollection[i].OnParentBindingContextChanged(e);
                }
            }
        } 

        ///  
        ///  
        ///    [To be supplied.]
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnCausesValidationChanged(EventArgs e) {
            EventHandler eh = Events[EventCausesValidation] as EventHandler;
            if (eh != null) { 
                 eh(this, e);
            } 
        } 

        ///  
        /// 
        ///     Called when a child is about to resume its layout.  The default implementation
        ///     calls OnChildLayoutResuming on the parent.
        ///  
        internal virtual void OnChildLayoutResuming(Control child, bool performLayout) {
            if (ParentInternal != null) { 
                ParentInternal.OnChildLayoutResuming(child, performLayout); 
            }
        } 

        /// 
        /// 
        ///    [To be supplied.] 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual void OnContextMenuChanged(EventArgs e) { 
            EventHandler eh = Events[EventContextMenu] as EventHandler;
            if (eh != null) { 
                 eh(this, e);
            }
        }
 
        /// 
        ///  
        ///    [To be supplied.] 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual void OnContextMenuStripChanged(EventArgs e) {
            EventHandler eh = Events[EventContextMenuStrip] as EventHandler;
            if (eh != null) {
                eh(this, e); 
            }
        } 
 
        /// 
        ///  
        ///    [To be supplied.]
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnCursorChanged(EventArgs e) { 
            EventHandler eh = Events[EventCursor] as EventHandler;
            if (eh != null) { 
                 eh(this, e); 
            }
 
            ControlCollection controlsCollection = (ControlCollection)Properties.GetObject(PropControlsCollection);
            if (controlsCollection != null) {
                // PERFNOTE: This is more efficient than using Foreach.  Foreach
                // forces the creation of an array subset enum each time we 
                // enumerate
                for(int i = 0; i < controlsCollection.Count; i++) { 
                    controlsCollection[i].OnParentCursorChanged(e); 
                }
            } 
        }

        /// 
        ///  
        ///    [To be supplied.]
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual void OnDockChanged(EventArgs e) {
            EventHandler eh = Events[EventDock] as EventHandler; 
            if (eh != null) {
                 eh(this, e);
            }
        } 

        ///  
        ///  
        /// Raises the  event.
        /// Inheriting classes should override this method to handle this event. 
        ///    Call base.OnEnabled to send this event to any registered event listeners.
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnEnabledChanged(EventArgs e) { 
            if (GetAnyDisposingInHierarchy()) {
                return; 
            } 

            if (IsHandleCreated) { 
                SafeNativeMethods.EnableWindow(new HandleRef(this, Handle), Enabled);

                // User-paint controls should repaint when their enabled state changes
                // 
                if (GetStyle(ControlStyles.UserPaint)) {
                    Invalidate(); 
                    Update(); 
                }
            } 

            EventHandler eh = Events[EventEnabled] as EventHandler;
            if (eh != null) {
                eh(this, e); 
            }
 
            ControlCollection controlsCollection = (ControlCollection)Properties.GetObject(PropControlsCollection); 
            if (controlsCollection != null) {
                // PERFNOTE: This is more efficient than using Foreach.  Foreach 
                // forces the creation of an array subset enum each time we
                // enumerate
                for(int i = 0; i < controlsCollection.Count; i++) {
                    controlsCollection[i].OnParentEnabledChanged(e); 
                }
            } 
        } 

        // Refer VsWhidbey : 515910 & 269769 
        internal virtual void OnFrameWindowActivate(bool fActivate) {
        }

        ///  
        /// 
        ///    [To be supplied.] 
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnFontChanged(EventArgs e) { 
            // bail if disposing
            //
            if (GetAnyDisposingInHierarchy()) {
                return; 
            }
 
            Invalidate(); 

            if (Properties.ContainsInteger(PropFontHeight)) { 
                Properties.SetInteger(PropFontHeight, -1);
            }

 
            // Cleanup any font handle wrapper...
            // 
            DisposeFontHandle(); 

            if (IsHandleCreated && !GetStyle(ControlStyles.UserPaint)) { 
                SetWindowFont();
            }

            EventHandler eh = Events[EventFont] as EventHandler; 
            if (eh != null) {
                 eh(this, e); 
            } 

            ControlCollection controlsCollection = (ControlCollection)Properties.GetObject(PropControlsCollection); 
            using(new LayoutTransaction(this, this, PropertyNames.Font, false)) {
                if (controlsCollection != null) {
                    // This may have changed the sizes of our children.
                    // PERFNOTE: This is more efficient than using Foreach.  Foreach 
                    // forces the creation of an array subset enum each time we
                    // enumerate 
                    for(int i = 0; i < controlsCollection.Count; i++) { 
                        controlsCollection[i].OnParentFontChanged(e);
                    } 
                }
            }

            LayoutTransaction.DoLayout(this,this,PropertyNames.Font); 
        }
 
        ///  
        /// 
        ///    [To be supplied.] 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnForeColorChanged(EventArgs e) {
            if (GetAnyDisposingInHierarchy()) { 
                return;
            } 
 
            Invalidate();
 
            EventHandler eh = Events[EventForeColor] as EventHandler;
            if (eh != null) {
                 eh(this, e);
            } 

            ControlCollection controlsCollection = (ControlCollection)Properties.GetObject(PropControlsCollection); 
            if (controlsCollection != null) { 
                // PERFNOTE: This is more efficient than using Foreach.  Foreach
                // forces the creation of an array subset enum each time we 
                // enumerate
                for(int i = 0; i < controlsCollection.Count; i++) {
                    controlsCollection[i].OnParentForeColorChanged(e);
                } 
            }
        } 
 
        /// 
        ///  
        ///    [To be supplied.]
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnRightToLeftChanged(EventArgs e) { 
            if (GetAnyDisposingInHierarchy()) {
                return; 
            } 

            // update the scroll position when the handle has been created 
            // MUST SET THIS BEFORE CALLING RecreateHandle!!!
            SetState2(STATE2_SETSCROLLPOS, true);

            RecreateHandle(); 

            EventHandler eh = Events[EventRightToLeft] as EventHandler; 
            if (eh != null) { 
                 eh(this, e);
            } 

            ControlCollection controlsCollection = (ControlCollection)Properties.GetObject(PropControlsCollection);
            if (controlsCollection != null) {
                // PERFNOTE: This is more efficient than using Foreach.  Foreach 
                // forces the creation of an array subset enum each time we
                // enumerate 
                for(int i = 0; i < controlsCollection.Count; i++) { 
                    controlsCollection[i].OnParentRightToLeftChanged(e);
                } 
            }
        }

        ///  
        /// 
        ///    OnNotifyMessage is called if the ControlStyles.EnableNotifyMessage 
        ///    bit is set. This allows for semi-trusted controls to listen to 
        ///    window messages, without allowing them to actually modify the
        ///    message. 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnNotifyMessage(Message m) {
        } 

        ///  
        ///  
        ///    [To be supplied.]
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnParentBackColorChanged(EventArgs e) {
            Color backColor = Properties.GetColor(PropBackColor);
            if (backColor.IsEmpty) { 
                OnBackColorChanged(e);
            } 
        } 

        ///  
        /// 
        ///    [To be supplied.]
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual void OnParentBackgroundImageChanged(EventArgs e) {
            OnBackgroundImageChanged(e); 
        } 

        ///  
        /// 
        ///    [To be supplied.]
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual void OnParentBindingContextChanged(EventArgs e) {
            if (Properties.GetObject(PropBindingManager) == null) { 
                OnBindingContextChanged(e); 
            }
        } 

        /// 
        /// 
        ///    [To be supplied.] 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual void OnParentCursorChanged(EventArgs e) { 
            if (Properties.GetObject(PropCursor) == null) {
                OnCursorChanged(e); 
            }
        }

        ///  
        /// 
        ///    [To be supplied.] 
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnParentEnabledChanged(EventArgs e) { 
            if (GetState(STATE_ENABLED)) {
                OnEnabledChanged(e);
            }
        } 

        ///  
        ///  
        ///    [To be supplied.]
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnParentFontChanged(EventArgs e) {
            if (Properties.GetObject(PropFont) == null) {
                OnFontChanged(e); 
            }
        } 
 

        // occurs when the parent of this control has recreated 
        // its handle.
        // presently internal as we feel this will be rare to
        // require override
        internal virtual void OnParentHandleRecreated() { 
            // restore ourselves over to the original control.
 
            // use SetParent directly so as to not raise ParentChanged events 
            Control parent = ParentInternal;
            if (parent != null) { 
                if (IsHandleCreated) {
                    UnsafeNativeMethods.SetParent(new HandleRef(this, this.Handle), new HandleRef(parent, parent.Handle));
                    UpdateZOrder();
                } 
            }
            SetState(STATE_PARENTRECREATING, false); 
 
            // if our parent was initially the the parent who's handle just got recreated, we need
            // to recreate ourselves so that we get notification.  See UpdateReflectParent for more details. 
            if (ReflectParent == ParentInternal)  {
                 RecreateHandle();
            }
 
        }
 
 
        // occurs when the parent of this control is recreating
        // its handle. 
        // presently internal as we feel this will be rare to
        // require override
        internal virtual void  OnParentHandleRecreating() {
            SetState(STATE_PARENTRECREATING, true); 
            // swoop this control over to the parking window.
 
            // if we left it parented to the parent control, the DestroyWindow 
            // would force us to destroy our handle as well... hopefully
            // parenting us over to the parking window and restoring ourselves 
            // should help improve recreate perf.

            // use SetParent directly so as to not raise ParentChanged events
            if (IsHandleCreated) { 
                Application.ParkHandle(new HandleRef(this, this.Handle));
            } 
        } 

        ///  
        /// 
        ///    [To be supplied.]
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual void OnParentForeColorChanged(EventArgs e) {
            Color foreColor = Properties.GetColor(PropForeColor); 
            if (foreColor.IsEmpty) { 
                OnForeColorChanged(e);
            } 
        }

        /// 
        ///  
        ///    [To be supplied.]
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual void OnParentRightToLeftChanged(EventArgs e) {
            if (!Properties.ContainsInteger(PropRightToLeft) || ((RightToLeft)Properties.GetInteger(PropRightToLeft)) == RightToLeft.Inherit) { 
                OnRightToLeftChanged(e);
            }
        }
 
        /// 
        ///  
        ///    [To be supplied.] 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual void OnParentVisibleChanged(EventArgs e) {
            if (GetState(STATE_VISIBLE)) {
                OnVisibleChanged(e);
            } 
        }
 
        // Used to work around VSWhidbey 527459. OnVisibleChanged/OnParentVisibleChanged is not called when a parent becomes invisible 
        internal virtual void OnParentBecameInvisible() {
            if (GetState(STATE_VISIBLE)) { 
                // This control became invisible too - notify its children
                ControlCollection controlsCollection = (ControlCollection)Properties.GetObject(PropControlsCollection);
                if (controlsCollection != null) {
                    for(int i = 0; i < controlsCollection.Count; i++) { 
                        Control ctl = controlsCollection[i];
                            ctl.OnParentBecameInvisible(); 
                    } 
                }
            } 
        }

        /// 
        ///  
        ///     Inheriting classes should override this method to handle this event.
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual void OnPrint(PaintEventArgs e) {
            if (e == null) { 
                throw new ArgumentNullException("e");
            }

            if (GetStyle(ControlStyles.UserPaint)) { 
                // Theme support on Windows XP requires that we paint the background
                // and foreground to support semi-transparent children 
                // 
                PaintWithErrorHandling(e, PaintLayerBackground);
                e.ResetGraphics(); 
                PaintWithErrorHandling(e, PaintLayerForeground);
            }
            else {
                PrintPaintEventArgs ppev = e as PrintPaintEventArgs; 
                Message m;
                bool releaseDC = false; 
                IntPtr hdc = IntPtr.Zero; 

                if (ppev == null) { 
                    IntPtr flags = (IntPtr)(NativeMethods.PRF_CHILDREN | NativeMethods.PRF_CLIENT | NativeMethods.PRF_ERASEBKGND | NativeMethods.PRF_NONCLIENT);
                    hdc = e.HDC;

                    if (hdc == IntPtr.Zero) { 
                        // a manually created paintevent args
                        hdc = e.Graphics.GetHdc(); 
                        releaseDC = true; 
                    }
                    m = Message.Create(this.Handle, NativeMethods.WM_PRINTCLIENT, hdc, flags); 
                }
                else {
                    m = ppev.Message;
                } 

                try { 
                    DefWndProc(ref m); 
                }
                finally { 
                    if (releaseDC) {
                        e.Graphics.ReleaseHdcInternal(hdc);
                    }
                } 
            }
        } 
 
        /// 
        ///  
        ///    [To be supplied.]
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnTabIndexChanged(EventArgs e) { 
            EventHandler eh = Events[EventTabIndex] as EventHandler;
            if (eh != null) { 
                 eh(this, e); 
            }
        } 

        /// 
        /// 
        ///    [To be supplied.] 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual void OnTabStopChanged(EventArgs e) { 
            EventHandler eh = Events[EventTabStop] as EventHandler;
            if (eh != null) { 
                 eh(this, e);
            }
        }
 
        /// 
        ///  
        ///    [To be supplied.] 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual void OnTextChanged(EventArgs e) {
            EventHandler eh = Events[EventText] as EventHandler;
            if (eh != null) {
                 eh(this, e); 
            }
        } 
 
        /// 
        ///  
        /// Raises the  event.
        /// Inheriting classes should override this method to handle this event.
        ///    Call base.OnVisible to send this event to any registered event listeners.
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnVisibleChanged(EventArgs e) { 
            bool visible = this.Visible; 
            if (visible) {
                UnhookMouseEvent(); 
                trackMouseEvent = null;
            }
            if (parent != null && visible && !Created) {
                bool isDisposing = GetAnyDisposingInHierarchy(); 
                if (!isDisposing) {
                    // Usually the control is created by now, but in a few corner cases 
                    // exercised by the PropertyGrid dropdowns, it isn't 
                    CreateControl();
                } 
            }

            EventHandler eh = Events[EventVisible] as EventHandler;
            if (eh != null) { 
                eh(this, e);
            } 
 
            ControlCollection controlsCollection = (ControlCollection)Properties.GetObject(PropControlsCollection);
            if (controlsCollection != null) { 
                // PERFNOTE: This is more efficient than using Foreach.  Foreach
                // forces the creation of an array subset enum each time we
                // enumerate
                for(int i = 0; i < controlsCollection.Count; i++) { 
                    Control ctl = controlsCollection[i];
                    if (ctl.Visible) { 
                        ctl.OnParentVisibleChanged(e); 
                    }
                    if (!visible) { 
                        ctl.OnParentBecameInvisible();
                    }
                }
            } 
        }
 
        ///  
        internal virtual void OnTopMostActiveXParentChanged(EventArgs e) {
            ControlCollection controlsCollection = (ControlCollection)Properties.GetObject(PropControlsCollection); 
            if (controlsCollection != null) {
                // PERFNOTE: This is more efficient than using Foreach.  Foreach
                // forces the creation of an array subset enum each time we
                // enumerate 
                for(int i = 0; i < controlsCollection.Count; i++) {
                    controlsCollection[i].OnTopMostActiveXParentChanged(e); 
                } 
            }
        } 

        /// 
        /// 
        ///    [To be supplied.] 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual void OnParentChanged(EventArgs e) { 
            EventHandler eh = Events[EventParent] as EventHandler;
            if (eh != null) { 
                eh(this, e);
            }

            // 
            // Inform the control that the topmost control is now an ActiveX control
            if (TopMostParent.IsActiveX) { 
                OnTopMostActiveXParentChanged(EventArgs.Empty); 
            }
        } 

        /// 
        /// 
        /// Raises the  
        /// event.
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual void OnClick(EventArgs e) {
            EventHandler handler = (EventHandler)Events[EventClick]; 
            if (handler != null) handler(this, e);
        }

        ///  
        /// 
        ///    [To be supplied.] 
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnClientSizeChanged(EventArgs e) { 
            EventHandler eh = Events[EventClientSize] as EventHandler;
            if (eh != null) {
                eh(this,e);
            } 
        }
 
        ///  
        /// 
        /// Raises the  event. 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnControlAdded(ControlEventArgs e) {
            ControlEventHandler handler = (ControlEventHandler)Events[EventControlAdded]; 
            if (handler != null) handler(this, e);
        } 
 
        /// 
        ///  
        /// Raises the  event.
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnControlRemoved(ControlEventArgs e) { 
            ControlEventHandler handler = (ControlEventHandler)Events[EventControlRemoved];
            if (handler != null) handler(this, e); 
        } 

        ///  
        /// 
        ///    Called when the control is first created.
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual void OnCreateControl() {
        } 
 
        /// 
        ///  
        ///     Inheriting classes should override this method to find out when the
        ///     handle has been created.
        ///     Call base.OnHandleCreated first.
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnHandleCreated(EventArgs e) { 
 
            if (this.IsHandleCreated) {
                // Setting fonts is for some reason incredibly expensive. 
                // (Even if you exclude font handle creation)
                if (!GetStyle(ControlStyles.UserPaint)){
                    SetWindowFont();
                } 

                // Restore dragdrop status. Ole Initialize happens 
                // when the ThreadContext in Application is created 
                //
                SetAcceptDrops(AllowDrop); 

                Region region = (Region)Properties.GetObject(PropRegion);
                if (region != null) {
                    IntPtr regionHandle = GetHRgn(region); 

                    try { 
                        if (IsActiveX) { 
                            regionHandle = ActiveXMergeRegion(regionHandle);
                        } 

                        if (UnsafeNativeMethods.SetWindowRgn(new HandleRef(this, Handle), new HandleRef(this, regionHandle), SafeNativeMethods.IsWindowVisible(new HandleRef(this, Handle))) != 0) {
                            //The HWnd owns the region.
                            regionHandle = IntPtr.Zero; 
                        }
                    } 
                    finally { 
                        if (regionHandle != IntPtr.Zero) {
                            SafeNativeMethods.DeleteObject(new HandleRef(null, regionHandle)); 
                        }
                    }
                }
 
                // Update accessbility information.
                // 
                ControlAccessibleObject accObj = Properties.GetObject(PropAccessibility) as ControlAccessibleObject; 
                ControlAccessibleObject ncAccObj = Properties.GetObject(PropNcAccessibility) as ControlAccessibleObject;
 
                // Cache Handle in a local before asserting so we minimize code running under the Assert.
                IntPtr handle = Handle;

                // Reviewed  : ControlAccessibleObject.set_Handle demands UnmanagedCode permission for public use, it doesn't 
                //             expose any security vulnerability indirectly. The sec Assert is safe.
                // 
                IntSecurity.UnmanagedCode.Assert(); 

                try { 
                    if (accObj != null) {
                        accObj.Handle = handle;
                    }
                    if (ncAccObj != null) { 
                        ncAccObj.Handle = handle;
                    } 
                } 
                finally {
                    CodeAccessPermission.RevertAssert(); 
                }

                // Set the window text from the Text property.
                // 
                if (text != null && text.Length != 0) {
                    UnsafeNativeMethods.SetWindowText(new HandleRef(this, Handle), text); 
                } 

                if (!(this is ScrollableControl) && !IsMirrored && GetState2(STATE2_SETSCROLLPOS) && !GetState2(STATE2_HAVEINVOKED)) { 
                    BeginInvoke(new EventHandler(this.OnSetScrollPosition));
                    SetState2(STATE2_HAVEINVOKED, true);
                    SetState2(STATE2_SETSCROLLPOS, false);
                } 

                // Listen to UserPreferenceChanged if the control is top level and interested in the notification. 
                if (GetState2(STATE2_INTERESTEDINUSERPREFERENCECHANGED)) { 
                    ListenToUserPreferenceChanged(GetTopLevel());
                } 
            }

            EventHandler handler = (EventHandler)Events[EventHandleCreated];
            if (handler != null) handler(this, e); 

            if (this.IsHandleCreated) 
            { 
                // Now, repost the thread callback message if we found it.  We should do
                // this last, so we're as close to the same state as when the message 
                // was placed.
                //
                if (GetState(STATE_THREADMARSHALLPENDING)) {
                    UnsafeNativeMethods.PostMessage(new HandleRef(this, Handle), threadCallbackMessage, IntPtr.Zero, IntPtr.Zero); 
                    SetState(STATE_THREADMARSHALLPENDING, false);
                } 
            } 
        }
 
        private void OnSetScrollPosition(object sender, EventArgs e) {
            SetState2(STATE2_HAVEINVOKED, false);
            OnInvokedSetScrollPosition(sender, e);
        } 

        internal virtual void OnInvokedSetScrollPosition(object sender, EventArgs e) { 
            if (!(this is ScrollableControl) && !IsMirrored) { 
                NativeMethods.SCROLLINFO si = new NativeMethods.SCROLLINFO();
                si.cbSize = Marshal.SizeOf(typeof(NativeMethods.SCROLLINFO)); 
                si.fMask = NativeMethods.SIF_RANGE;
                if (UnsafeNativeMethods.GetScrollInfo(new HandleRef(this, Handle), NativeMethods.SB_HORZ,si) != false) {
                    si.nPos = (RightToLeft == RightToLeft.Yes) ? si.nMax : si.nMin;
                    SendMessage(NativeMethods.WM_HSCROLL, NativeMethods.Util.MAKELPARAM(NativeMethods.SB_THUMBPOSITION, si.nPos), 0); 
                }
            } 
        } 

        ///  
        /// 
        ///    [To be supplied.]
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual void OnLocationChanged(EventArgs e) {
            OnMove(EventArgs.Empty); 
 
            EventHandler eh = Events[EventLocation] as EventHandler;
            if (eh != null) { 
                eh(this,e);
            }
        }
 
        /// 
        ///  
        ///     Inheriting classes should override this method to find out when the 
        ///     handle is about to be destroyed.
        ///     Call base.OnHandleDestroyed last. 
        /// Raises the  event.
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnHandleDestroyed(EventArgs e) { 
            EventHandler handler = (EventHandler)Events[EventHandleDestroyed];
            if (handler != null) handler(this, e); 
 
            UpdateReflectParent(false);
 
            if (!RecreatingHandle) {
                if (GetState(STATE_OWNCTLBRUSH)) {
                    object backBrush = Properties.GetObject(PropBackBrush);
                    if (backBrush != null) { 
                        IntPtr p = (IntPtr)backBrush;
                        if (p != IntPtr.Zero) { 
                            SafeNativeMethods.DeleteObject(new HandleRef(this, p)); 
                        }
                        Properties.SetObject(PropBackBrush, null); 
                    }
                }
                ListenToUserPreferenceChanged(false /*listen*/);
            } 

            // this code is important -- it is critical that we stash away 
            // the value of the text for controls such as edit, button, 
            // label, etc. Without this processing, any time you change a
            // property that forces handle recreation, you lose your text! 
            // See the above code in wmCreate
            //

            try { 
                if (!GetAnyDisposingInHierarchy()) {
                    text = Text; 
                    if (text != null && text.Length == 0) text = null; 
                }
                SetAcceptDrops(false); 
            }
            catch (Exception ex) {
                if (ClientUtils.IsSecurityOrCriticalException(ex)) {
                    throw; 
                }
 
                // Some ActiveX controls throw exceptions when 
                // you ask for the text property after you have destroyed their handle. We
                // don't want those exceptions to bubble all the way to the top, since 
                // we leave our state in a mess. See ASURT 49990.
                //
            }
        } 

        ///  
        ///  
        /// Raises the  event.
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnDoubleClick(EventArgs e) {
            EventHandler handler = (EventHandler)Events[EventDoubleClick];
            if (handler != null) handler(this,e); 
        }
 
        ///  
        /// 
        /// Raises the  event. 
        /// Inheriting classes should override this method to handle this event.
        ///    Call base.onEnter to send this event to any registered event listeners.
        /// 
        ///  
        ///     Inheriting classes should override this method to handle this event.
        ///     Call base.onDragEnter to send this event to any registered event listeners. 
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnDragEnter(DragEventArgs drgevent) { 
            DragEventHandler handler = (DragEventHandler)Events[EventDragEnter];
            if (handler != null) handler(this,drgevent);
        }
 
        /// 
        ///  
        ///     Inheriting classes should override this method to handle this event. 
        ///     Call base.onDragOver to send this event to any registered event listeners.
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnDragOver(DragEventArgs drgevent) {
            DragEventHandler handler = (DragEventHandler)Events[EventDragOver];
            if (handler != null) handler(this,drgevent); 
        }
 
        ///  
        /// 
        ///     Inheriting classes should override this method to handle this event. 
        ///     Call base.onDragLeave to send this event to any registered event listeners.
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnDragLeave(EventArgs e) { 
            EventHandler handler = (EventHandler)Events[EventDragLeave];
            if (handler != null) handler(this,e); 
        } 

        ///  
        /// 
        ///     Inheriting classes should override this method to handle this event.
        ///     Call base.onDragDrop to send this event to any registered event listeners.
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnDragDrop(DragEventArgs drgevent) { 
            DragEventHandler handler = (DragEventHandler)Events[EventDragDrop]; 
            if (handler != null) handler(this,drgevent);
        } 

        /// 
        /// 
        ///     Inheriting classes should override this method to handle this event. 
        ///     Call base.onGiveFeedback to send this event to any registered event listeners.
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        [SuppressMessage("Microsoft.Security", "CA2119:SealMethodsThatSatisfyPrivateInterfaces")]
        protected virtual void OnGiveFeedback(GiveFeedbackEventArgs gfbevent) { 
            GiveFeedbackEventHandler handler = (GiveFeedbackEventHandler)Events[EventGiveFeedback];
            if (handler != null) handler(this,gfbevent);
        }
 
        /// 
        ///  
        ///    [To be supplied.] 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual void OnEnter(EventArgs e) {
            EventHandler handler = (EventHandler)Events[EventEnter];
            if (handler != null) handler(this,e);
        } 

        ///  
        ///  
        /// Raises the  event.
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected void InvokeGotFocus(Control toInvoke, EventArgs e) {
            if (toInvoke != null) {
                toInvoke.OnGotFocus(e); 
            }
        } 
 
        /// 
        ///  
        /// Raises the  event.
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnGotFocus(EventArgs e) { 
            if (IsActiveX) {
                ActiveXOnFocus(true); 
            } 

            if (parent != null) { 
                parent.ChildGotFocus(this);
            }

            EventHandler handler = (EventHandler)Events[EventGotFocus]; 
            if (handler != null) handler(this,e);
        } 
 
        /// 
        ///  
        ///     Inheriting classes should override this method to handle this event.
        ///     Call base.onHelp to send this event to any registered event listeners.
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual void OnHelpRequested(HelpEventArgs hevent) {
            HelpEventHandler handler = (HelpEventHandler)Events[EventHelpRequested]; 
            if (handler != null) { 
                handler(this,hevent);
                // VSWhidbey 95281: Set this to true so that multiple events aren't raised to the Form. 
                hevent.Handled = true;
            }

            if (!hevent.Handled) { 
                if (ParentInternal != null) {
                    ParentInternal.OnHelpRequested(hevent); 
                } 
            }
        } 

        /// 
        /// 
        ///     Inheriting classes should override this method to handle this event. 
        ///     Call base.OnInvalidate to send this event to any registered event listeners.
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual void OnInvalidated(InvalidateEventArgs e) {
            // Ask the site to change the view... 
            if (IsActiveX) {
                ActiveXViewChanged();
            }
 
            // Transparent control support
            ControlCollection controls = (ControlCollection)Properties.GetObject(PropControlsCollection); 
            if (controls != null) { 
                // PERFNOTE: This is more efficient than using Foreach.  Foreach
                // forces the creation of an array subset enum each time we 
                // enumerate
                for(int i = 0; i < controls.Count; i++) {
                    controls[i].OnParentInvalidated(e);
                } 
            }
 
            InvalidateEventHandler handler = (InvalidateEventHandler)Events[EventInvalidated]; 
            if (handler != null) handler(this, e);
        } 

        /// 
        /// 
        /// Raises the  event. 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual void OnKeyDown(KeyEventArgs e) { 
            KeyEventHandler handler = (KeyEventHandler)Events[EventKeyDown];
            if (handler != null) handler(this,e); 
        }

        /// 
        ///  
        /// Raises the  event.
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual void OnKeyPress(KeyPressEventArgs e) {
            KeyPressEventHandler handler = (KeyPressEventHandler)Events[EventKeyPress]; 
            if (handler != null) handler(this,e);
        }

        ///  
        /// 
        /// Raises the  event. 
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnKeyUp(KeyEventArgs e) { 
            KeyEventHandler handler = (KeyEventHandler)Events[EventKeyUp];
            if (handler != null) handler(this,e);
        }
 
        /// 
        ///  
        ///     Core layout logic. Inheriting controls should override this function 
        ///     to do any custom layout logic. It is not neccessary to call
        ///     base.layoutCore, however for normal docking and anchoring 
        ///     functions to work, base.layoutCore must be called.
        /// Raises the  event.
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual void OnLayout(LayoutEventArgs levent) {
            // Ask the site to change the view... 
            if (IsActiveX) { 
                ActiveXViewChanged();
            } 
            LayoutEventHandler handler = (LayoutEventHandler)Events[EventLayout];
            if (handler != null) handler(this, levent);

            bool parentRequiresLayout = LayoutEngine.Layout(this, levent); 

            // 
 

            if(parentRequiresLayout && ParentInternal != null) { 
                // LayoutEngine.Layout can return true to request that our parent resize us because
                // we did not have enough room for our contents.  We can not just call PerformLayout
                // because this container is currently suspended.  PerformLayout will check this state
                // flag and PerformLayout on our parent. 
                ParentInternal.SetState(STATE_LAYOUTISDIRTY, true);
            } 
        } 

        ///  
        /// 
        ///     Called when the last resume layout call is made.  If performLayout is true
        ///     a layout will occur as soon as this call returns.  Layout is
        ///     still suspended when this call is made.  The default implementation 
        ///     calls OnChildLayoutResuming on the parent, if it exists.
        ///  
        internal virtual void OnLayoutResuming(bool performLayout) { 
            if (ParentInternal != null) {
                ParentInternal.OnChildLayoutResuming(this, performLayout); 
            }
        }

        internal virtual void OnLayoutSuspended() { 
        }
 
        ///  
        /// 
        /// Raises the  event. 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnLeave(EventArgs e) {
            EventHandler handler = (EventHandler)Events[EventLeave]; 
            if (handler != null) handler(this, e);
        } 
 
        /// 
        ///  
        ///    [To be supplied.]
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected void InvokeLostFocus(Control toInvoke, EventArgs e) { 
            if (toInvoke != null) {
                toInvoke.OnLostFocus(e); 
            } 
        }
 
        /// 
        /// 
        /// Raises the  event.
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnLostFocus(EventArgs e) { 
            if (IsActiveX) { 
                ActiveXOnFocus(false);
            } 

            EventHandler handler = (EventHandler)Events[EventLostFocus];
            if (handler != null) handler(this, e);
        } 

        protected virtual void OnMarginChanged(EventArgs e) { 
            EventHandler handler = (EventHandler)Events[EventMarginChanged]; 
            if (handler != null) handler(this, e);
        } 

        /// 
        /// 
        /// Raises the  event. 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual void OnMouseDoubleClick(MouseEventArgs e) { 
            MouseEventHandler handler = (MouseEventHandler)Events[EventMouseDoubleClick];
            if (handler != null) handler(this, e); 
        }

        /// 
        ///  
        /// Raises the  event.
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual void OnMouseClick(MouseEventArgs e) {
            MouseEventHandler handler = (MouseEventHandler)Events[EventMouseClick]; 
            if (handler != null) handler(this, e);
        }

        ///  
        /// 
        /// Raises the  event. 
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnMouseCaptureChanged(EventArgs e) { 
            EventHandler handler = (EventHandler)Events[EventMouseCaptureChanged];
            if (handler != null) handler(this, e);
        }
 
        /// 
        ///  
        /// Raises the  event. 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual void OnMouseDown(MouseEventArgs e) {
            MouseEventHandler handler = (MouseEventHandler)Events[EventMouseDown];
            if (handler != null) handler(this, e);
        } 

        ///  
        ///  
        /// Raises the  event.
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnMouseEnter(EventArgs e) {
            EventHandler handler = (EventHandler)Events[EventMouseEnter];
            if (handler != null) handler(this, e); 
        }
 
        ///  
        /// 
        /// Raises the  event. 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnMouseLeave(EventArgs e) {
            EventHandler handler = (EventHandler)Events[EventMouseLeave]; 
            if (handler != null) handler(this, e);
        } 
 
        /// 
        ///  
        /// Raises the  event.
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnMouseHover(EventArgs e) { 
            EventHandler handler = (EventHandler)Events[EventMouseHover];
            if (handler != null) handler(this, e); 
        } 

        ///  
        /// 
        /// Raises the  event.
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual void OnMouseMove(MouseEventArgs e) {
            MouseEventHandler handler = (MouseEventHandler)Events[EventMouseMove]; 
            if (handler != null) handler(this, e); 
        }
 
        /// 
        /// 
        /// Raises the  event.
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnMouseUp(MouseEventArgs e) { 
            MouseEventHandler handler = (MouseEventHandler)Events[EventMouseUp]; 
            if (handler != null) handler(this, e);
        } 

        /// 
        /// 
        /// Raises the  event. 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual void OnMouseWheel(MouseEventArgs e) { 
            MouseEventHandler handler = (MouseEventHandler)Events[EventMouseWheel];
            if (handler != null) handler(this, e); 
        }

        /// 
        ///  
        /// Raises the  event.
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual void OnMove(EventArgs e) {
            EventHandler handler = (EventHandler)Events[EventMove]; 
            if (handler != null) handler(this, e);
            if (RenderTransparent)
                Invalidate();
        } 

        ///  
        ///  
        ///     Inheriting classes should override this method to handle this event.
        ///     Call base.onPaint to send this event to any registered event listeners. 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnPaint(PaintEventArgs e) {
            PaintEventHandler handler = (PaintEventHandler)Events[EventPaint]; 
            if (handler != null) handler(this, e);
        } 
 
        protected virtual void OnPaddingChanged(EventArgs e) {
            if (GetStyle(ControlStyles.ResizeRedraw)) { 
                Invalidate();
            }
            EventHandler handler = (EventHandler)Events[EventPaddingChanged];
            if (handler != null) handler(this, e); 
        }
 
 
        /// 
        ///  
        ///     Inheriting classes should override this method to handle the erase
        ///     background request from windows. It is not necessary to call
        ///     base.onPaintBackground, however if you do not want the default
        ///     Windows behavior you must set event.handled to true. 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual void OnPaintBackground(PaintEventArgs pevent) { 

            // We need the true client rectangle as clip rectangle causes 
            // problems on "Windows Classic" theme.
            NativeMethods.RECT rect = new NativeMethods.RECT();
            UnsafeNativeMethods.GetClientRect(new HandleRef(window, InternalHandle), ref rect);
 
            PaintBackground(pevent, new Rectangle(rect.left, rect.top, rect.right, rect.bottom));
        } 
 
        // Transparent control support
        private void OnParentInvalidated(InvalidateEventArgs e) { 
            if (!RenderTransparent) return;

            if (this.IsHandleCreated) {
                // move invalid rect into child space 
                Rectangle cliprect = e.InvalidRect;
                Point offs = this.Location; 
                cliprect.Offset(-offs.X,-offs.Y); 
                cliprect = Rectangle.Intersect(this.ClientRectangle, cliprect);
 
                // if we don't intersect at all, do nothing
                if (cliprect.IsEmpty) return;
                this.Invalidate(cliprect);
            } 
        }
 
        ///  
        /// 
        ///     Inheriting classes should override this method to handle this event. 
        ///     Call base.onQueryContinueDrag to send this event to any registered event listeners.
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        [SuppressMessage("Microsoft.Security", "CA2119:SealMethodsThatSatisfyPrivateInterfaces")] 
        protected virtual void OnQueryContinueDrag(QueryContinueDragEventArgs qcdevent) {
            QueryContinueDragEventHandler handler = (QueryContinueDragEventHandler)Events[EventQueryContinueDrag]; 
            if (handler != null) handler(this, qcdevent); 
        }
 
        /// 
        /// 
        /// Raises the  event when the Region property has changed.
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnRegionChanged(EventArgs e) { 
           EventHandler eh = Events[EventRegionChanged] as EventHandler; 
           if (eh != null) {
                eh(this, e); 
           }
        }

        ///  
        /// 
        /// Raises the  event. 
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnResize(EventArgs e) { 
            if ((controlStyle & ControlStyles.ResizeRedraw) == ControlStyles.ResizeRedraw
                || GetState(STATE_EXCEPTIONWHILEPAINTING)) {
                Invalidate();
            } 
            LayoutTransaction.DoLayout(this, this, PropertyNames.Bounds);
            EventHandler handler = (EventHandler)Events[EventResize]; 
            if (handler != null) handler(this, e); 
        }
 
        /// 
        /// 
        /// Raises the  event.
        ///  
        [
        EditorBrowsable(EditorBrowsableState.Advanced), 
        SecurityPermission(SecurityAction.InheritanceDemand, Flags=SecurityPermissionFlag.UnmanagedCode), 
        SecurityPermission(SecurityAction.LinkDemand, Flags=SecurityPermissionFlag.UnmanagedCode),
        SuppressMessage("Microsoft.Security", "CA2109:ReviewVisibleEventHandlers") 
        ]
        protected virtual void OnPreviewKeyDown(PreviewKeyDownEventArgs e) {
            PreviewKeyDownEventHandler handler = (PreviewKeyDownEventHandler)Events[EventPreviewKeyDown];
            if (handler != null) { 
                handler(this, e);
            } 
        } 

        ///  
        /// 
        ///    [To be supplied.]
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual void OnSizeChanged(EventArgs e) {
            OnResize(EventArgs.Empty); 
 
            EventHandler eh = Events[EventSize] as EventHandler;
            if (eh != null) { 
                eh(this,e);
            }
        }
 
        /// 
        ///  
        /// Raises the  
        /// event.
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnChangeUICues(UICuesEventArgs e) {
            UICuesEventHandler handler = (UICuesEventHandler)Events[EventChangeUICues];
            if (handler != null) handler(this, e); 
        }
 
        ///  
        /// 
        /// Raises the  
        /// event.
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnStyleChanged(EventArgs e) { 
            EventHandler handler = (EventHandler)Events[EventStyleChanged];
            if (handler != null) handler(this, e); 
        } 

        ///  
        /// 
        /// Raises the 
        /// event.
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnSystemColorsChanged(EventArgs e) { 
            ControlCollection controlsCollection = (ControlCollection)Properties.GetObject(PropControlsCollection); 
            if (controlsCollection != null) {
                // PERFNOTE: This is more efficient than using Foreach.  Foreach 
                // forces the creation of an array subset enum each time we
                // enumerate
                for(int i = 0; i < controlsCollection.Count; i++) {
                    controlsCollection[i].OnSystemColorsChanged(EventArgs.Empty); 
                }
            } 
            Invalidate(); 

            EventHandler handler = (EventHandler)Events[EventSystemColorsChanged]; 
            if (handler != null) handler(this, e);
        }

        ///  
        /// 
        /// Raises the  
        /// event. 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual void OnValidating(CancelEventArgs e) {
            CancelEventHandler handler = (CancelEventHandler)Events[EventValidating];
            if (handler != null) handler(this, e);
        } 

        ///  
        ///  
        /// Raises the  event.
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void OnValidated(EventArgs e) {
            EventHandler handler = (EventHandler)Events[EventValidated];
            if (handler != null) handler(this, e); 
        }
 
        // This is basically OnPaintBackground, put in a separate method for ButtonBase, 
        // which does all painting under OnPaint, and tries very hard to avoid double-painting the border pixels.
        internal void PaintBackground(PaintEventArgs e, Rectangle rectangle) { 
            PaintBackground(e, rectangle, this.BackColor, Point.Empty);
        }

        internal void PaintBackground(PaintEventArgs e, Rectangle rectangle, Color backColor) { 
            PaintBackground(e, rectangle, backColor, Point.Empty);
        } 
 
        internal void PaintBackground(PaintEventArgs e, Rectangle rectangle, Color backColor, Point scrollOffset) {
            if (RenderColorTransparent(backColor)) { 
                PaintTransparentBackground(e, rectangle);
            }

            //If the form or mdiclient is mirrored then we do not render the background image due to GDI+ issues. 
            bool formRTL = ((this is Form || this is MdiClient) && this.IsMirrored);
 
            // The rest of this won't do much if BackColor is transparent and there is no BackgroundImage, 
            // but we need to call it in the partial alpha case.
 
            //

            if (BackgroundImage != null && !DisplayInformation.HighContrast && !formRTL) {
 
                if (BackgroundImageLayout == ImageLayout.Tile) {
                    if (ControlPaint.IsImageTransparent(BackgroundImage)) { 
                        PaintTransparentBackground(e, rectangle); 
                    }
                } 

                //

                Point scrollLocation = scrollOffset; 
                ScrollableControl scrollControl = this as ScrollableControl;
                if (scrollControl != null && scrollLocation != Point.Empty) { 
                    scrollLocation = ((ScrollableControl)this).AutoScrollPosition; 
                }
 
                if (ControlPaint.IsImageTransparent(BackgroundImage)) {
                    PaintBackColor(e, rectangle, backColor);
                }
 
                ControlPaint.DrawBackgroundImage(e.Graphics, BackgroundImage, backColor, BackgroundImageLayout, ClientRectangle, rectangle, scrollLocation, RightToLeft);
            } 
            else { 
                PaintBackColor(e, rectangle, backColor);
            } 
        }
        private static void PaintBackColor(PaintEventArgs e, Rectangle rectangle, Color backColor) {
            // Common case of just painting the background.  For this, we
            // use GDI because it is faster for simple things than creating 
            // a graphics object, brush, etc.  Also, we may be able to
            // use a system brush, avoiding the brush create altogether. 
            // 
            Color color = backColor;
 
            // Note: PaintEvent.HDC == 0 if GDI+ has used the HDC -- it wouldn't be safe for us
            // to use it without enough bookkeeping to negate any performance gain of using GDI.
            if (color.A == 255 && e.HDC != IntPtr.Zero && DisplayInformation.BitsPerPixel > 8) {
                using (WindowsGraphics wg = WindowsGraphics.FromHdc(e.HDC)) { 
                    color = wg.GetNearestColor(color);
 
                    using (WindowsBrush brush = new WindowsSolidBrush(wg.DeviceContext, color)) { 
                        wg.FillRectangle(brush, rectangle);
                    } 
                }
            }
            else {
                // don't paint anything from 100% transparent background 
                //
                if (color.A > 0) { 
                    if (color.A == 255) { 
                        color = e.Graphics.GetNearestColor(color);
                    } 

                    // Color has some transparency or we have no HDC, so we must
                    // fall back to using GDI+.
                    // 
                    using (Brush brush = new SolidBrush(color)) {
                        e.Graphics.FillRectangle(brush, rectangle); 
                    } 
                }
            } 
        }

        // Paints a red rectangle with a red X, painted on a white background
        private void PaintException(PaintEventArgs e) { 
#if false
            StringFormat stringFormat = ControlPaint.StringFormatForAlignment(ContentAlignment.TopLeft); 
            string exceptionText = Properties.GetObject(PropPaintingException).ToString(); 
            stringFormat.SetMeasurableCharacterRanges(new CharacterRange[] {new CharacterRange(0, exceptionText.Length)});
 
            // rendering calculations...
            //
            int penThickness = 2;
            Size glyphSize = SystemInformation.IconSize; 
            int marginX = penThickness * 2;
            int marginY = penThickness * 2; 
 
            Rectangle clientRectangle = ClientRectangle;
 
            Rectangle borderRectangle = ClientRectangle;
            borderRectangle.X++;
            borderRectangle.Y++;
            borderRectangle.Width -=2; 
            borderRectangle.Height-=2;
 
            Rectangle imageRect = new Rectangle(marginX, marginY, glyphSize.Width, glyphSize.Height); 

            Rectangle textRect = clientRectangle; 
            textRect.X = imageRect.X + imageRect.Width + 2 * marginX;
            textRect.Y = imageRect.Y;
            textRect.Width -= (textRect.X + marginX + penThickness);
            textRect.Height -= (textRect.Y + marginY + penThickness); 

            using (Font errorFont = new Font(Font.FontFamily, Math.Max(SystemInformation.ToolWindowCaptionHeight - SystemInformation.BorderSize.Height - 2, Font.Height), GraphicsUnit.Pixel)) { 
 
                using(Region textRegion = e.Graphics.MeasureCharacterRanges(exceptionText, errorFont, textRect, stringFormat)[0]) {
                    // paint contents... clipping optimizations for less flicker... 
                    //
                    Region originalClip = e.Graphics.Clip;

                    e.Graphics.ExcludeClip(textRegion); 
                    e.Graphics.ExcludeClip(imageRect);
                    try { 
                        e.Graphics.FillRectangle(Brushes.White, clientRectangle); 
                    }
                    finally { 
                        e.Graphics.Clip = originalClip;
                    }

                    using (Pen pen = new Pen(Color.Red, penThickness)) { 
                        e.Graphics.DrawRectangle(pen, borderRectangle);
                    } 
 
                    Icon err = SystemIcons.Error;
 
                    e.Graphics.FillRectangle(Brushes.White, imageRect);
                    e.Graphics.DrawIcon(err, imageRect.X, imageRect.Y);

                    textRect.X++; 
                    e.Graphics.IntersectClip(textRegion);
                    try { 
                        e.Graphics.FillRectangle(Brushes.White, textRect); 
                        e.Graphics.DrawString(exceptionText, errorFont, new SolidBrush(ForeColor), textRect, stringFormat);
                    } 
                    finally {
                        e.Graphics.Clip = originalClip;
                    }
                } 
            }
#else 
            int penThickness = 2; 
            using (Pen pen = new Pen(Color.Red, penThickness)) {
                Rectangle clientRectangle = ClientRectangle; 
                Rectangle rectangle = clientRectangle;
                rectangle.X++;
                rectangle.Y++;
                rectangle.Width--; 
                rectangle.Height--;
 
                e.Graphics.DrawRectangle(pen, rectangle.X, rectangle.Y, rectangle.Width - 1, rectangle.Height - 1); 
                rectangle.Inflate(-1, -1);
                e.Graphics.FillRectangle(Brushes.White, rectangle); 
                e.Graphics.DrawLine(pen, clientRectangle.Left, clientRectangle.Top,
                                    clientRectangle.Right, clientRectangle.Bottom);
                e.Graphics.DrawLine(pen, clientRectangle.Left, clientRectangle.Bottom,
                                    clientRectangle.Right, clientRectangle.Top); 
            }
 
#endif 
        }
 
        internal void PaintTransparentBackground(PaintEventArgs e, Rectangle rectangle) {
            PaintTransparentBackground(e,rectangle,null);
        }
        // Trick our parent into painting our background for us, or paint some default 
        // color if that doesn't work.
        // 
        // This method is the hardest part of implementing transparent controls; 
        // call this in your OnPaintBackground method, and away you go.
        // 
        // If you only want a region of the control to be transparent, pass in a region into the
        // last parameter.  A null region implies that you want the entire rectangle to be transparent.
        internal void PaintTransparentBackground(PaintEventArgs e, Rectangle rectangle, Region transparentRegion) {
            Graphics g = e.Graphics; 
            Control parent = this.ParentInternal;
 
            if (parent != null) { 
                // Refer to VSWhidbey : 440669.
                // We need to use themeing painting for certain controls (like TabPage) when they parent other controls. 
                // But we dont want to to this always as this causes serious preformance (at Runtime and DesignTime)
                // so checking for RenderTransparencyWithVisualStyles which is TRUE for TabPage and false by default.
                if (Application.RenderWithVisualStyles && parent.RenderTransparencyWithVisualStyles) {
                    // When we are rendering with visual styles, we can use the cool DrawThemeParentBackground function 
                    // that UxTheme provides to render the parent's background. This function is control agnostic, so
                    // we use the wrapper in ButtonRenderer - this should do the right thing for all controls, 
                    // not just Buttons. 

                    GraphicsState graphicsState = null; 
                    if (transparentRegion != null) {
                        graphicsState = g.Save();
                    }
                    try { 
                        if (transparentRegion != null) {
                            g.Clip = transparentRegion; 
                        } 
                        ButtonRenderer.DrawParentBackground(g, rectangle, this);
                    } 
                    finally {
                        if (graphicsState != null) {
                            g.Restore(graphicsState);
                        } 
                    }
 
 
                }
                else { 
                    // how to move the rendering area and setup it's size
                    // (we want to translate it to the parent's origin)
                    Rectangle shift = new Rectangle(-this.Left,-this.Top, parent.Width, parent.Height);
 
                    // moving the clipping rectangle to the parent coordinate system
                    Rectangle newClipRect = new Rectangle(rectangle.Left + this.Left, rectangle.Top + this.Top, rectangle.Width, rectangle.Height); 
 
                    using (WindowsGraphics wg = WindowsGraphics.FromGraphics(g)) {
                        wg.DeviceContext.TranslateTransform(-this.Left, -this.Top); 
                        using (PaintEventArgs np = new PaintEventArgs(wg.GetHdc(), newClipRect)) {
                            if (transparentRegion != null) {
                                np.Graphics.Clip = transparentRegion;
                                np.Graphics.TranslateClip(-shift.X, -shift.Y); 
                            }
                            try { 
                                InvokePaintBackground(parent, np); 
                                InvokePaint(parent, np);
                            } 
                            finally {
                                if (transparentRegion != null) {
                                    // restore region back to original state.
                                    np.Graphics.TranslateClip(shift.X, shift.Y); 
                                }
                            } 
                        } 
                    }
 
                }

            }
            else { 
                // For whatever reason, our parent can't paint our background, but we need some kind of background
                // since we're transparent. 
                g.FillRectangle(SystemBrushes.Control, rectangle); 
            }
        } 

        // Exceptions during painting are nasty, because paint events happen so often.
        // So if user painting code ----s up, we make sure never to call it again,
        // so as not to spam the end-user with exception dialogs. 
        //
        private void PaintWithErrorHandling(PaintEventArgs e, short layer) { 
            try { 
                CacheTextInternal = true;
                if (GetState(STATE_EXCEPTIONWHILEPAINTING)) { 
                    if (layer == PaintLayerBackground)
                        PaintException(e);
                }
                else { 
                    bool exceptionThrown = true;
                    try { 
                        switch (layer) { 
                            case PaintLayerForeground:
                                OnPaint(e); 
                                break;
                            case PaintLayerBackground:
                                if (!GetStyle(ControlStyles.Opaque)) {
                                    OnPaintBackground(e); 
                                }
                                break; 
                            default: 
                                Debug.Fail("Unknown PaintLayer " + layer);
                                break; 
                        }
                        exceptionThrown = false;
                    }
                    finally { 
                        if (exceptionThrown) {
                            SetState(STATE_EXCEPTIONWHILEPAINTING, true); 
                            Invalidate(); 
                        }
                    } 
                }
            }
            finally {
                CacheTextInternal = false; 
            }
        } 
 
        /// 
        ///  
        ///     Find ContainerControl that is the container of this control.
        /// 
        /// 
        // SECURITY WARNING: This property bypasses a security demand. Use with caution! 
        internal ContainerControl ParentContainerControl {
            get { 
                for (Control c = this.ParentInternal; c != null; c = c.ParentInternal) { 
                    if (c is ContainerControl) {
                        return c as ContainerControl; 
                    }
                }

                return null; 
            }
        } 
 
        /// 
        ///  
        ///     Forces the control to apply layout logic to all of the child controls.
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        public void PerformLayout() { 
            if (cachedLayoutEventArgs != null) {
                PerformLayout(cachedLayoutEventArgs); 
                cachedLayoutEventArgs = null; 

                // VSWhidbey 464817 - we need to be careful 
                // about which LayoutEventArgs are used in
                // SuspendLayout, PerformLayout, ResumeLayout() sequences.
                // See bug for more info.
                SetState2(STATE2_CLEARLAYOUTARGS, false); 
            }
            else { 
                PerformLayout(null, null); 
            }
        } 

        /// 
        /// 
        ///     Forces the control to apply layout logic to all of the child controls. 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        public void PerformLayout(Control affectedControl, string affectedProperty) { 
            PerformLayout(new LayoutEventArgs(affectedControl, affectedProperty));
        } 

        internal void PerformLayout(LayoutEventArgs args) {
            if (GetAnyDisposingInHierarchy()) {
                return; 
            }
 
            if (layoutSuspendCount > 0) { 
                SetState(STATE_LAYOUTDEFERRED, true);
                if (cachedLayoutEventArgs == null || (GetState2(STATE2_CLEARLAYOUTARGS) && args != null)) { 
                   cachedLayoutEventArgs = args;
                   if (GetState2(STATE2_CLEARLAYOUTARGS)) {
                    SetState2(STATE2_CLEARLAYOUTARGS, false);
                   } 
                }
 
                LayoutEngine.ProcessSuspendedLayoutEventArgs(this, args); 

                return; 
            }

            // (Essentially the same as suspending layout while we layout, but we clear differently below.)
            layoutSuspendCount = 1; 

            try { 
                CacheTextInternal = true; 
                OnLayout(args);
 
#if DEBUG
#if DEBUG_PREFERREDSIZE
                // DO NOT REMOVE - See http://wiki/default.aspx/Microsoft.Projects.DotNetClient.PreferredSize
                // PreferredSize has an assert that will verify that the current cached size matches 
                // the computed size.  The calls to PreferredSize below help to catch a mismatch earlier.
                if (!this.GetState(STATE_DISPOSING | STATE_DISPOSED)) { 
                    if (GetState2(STATE2_USEPREFERREDSIZECACHE)) { 
                        this.PreferredSize.ToString();
                    } 

                    if (args.AffectedControl != null && args.AffectedControl != this && args.AffectedControl.GetState2(STATE2_USEPREFERREDSIZECACHE)) {
                        args.AffectedControl.PreferredSize.ToString();
                    } 
                }
#endif 
#endif 

 
            }
            finally {
                CacheTextInternal = false;
                // Rather than resume layout (which will could allow a deferred layout to layout the 
                // the container we just finished laying out) we set layoutSuspendCount back to zero
                // and clear the deferred and dirty flags. 
                SetState(STATE_LAYOUTDEFERRED | STATE_LAYOUTISDIRTY, false); 
                layoutSuspendCount = 0;
 
                // LayoutEngine.Layout can return true to request that our parent resize us because
                // we did not have enough room for our contents.  Now that we are unsuspended,
                // see if this happened and layout parent if necessary.  (See also OnLayout)
                if(ParentInternal != null && ParentInternal.GetState(STATE_LAYOUTISDIRTY)) { 
                    LayoutTransaction.DoLayout(ParentInternal, this, PropertyNames.PreferredSize);
                } 
            } 
        }
 
        /// 
        ///     Peforms data validation (not paint validation!) on a single control.
        ///
        ///     Returns whether validation failed: 
        ///       False = Validation succeeded, control is valid, accept its new value
        ///       True = Validation was cancelled, control is invalid, reject its new value 
        /// 
        ///     NOTE: This is the lowest possible level of validation. It does not account
        ///     for the context in which the validation is occuring, eg. change of focus 
        ///     between controls in a container. Stuff like that is handled by the caller.
        /// 
        /// 
        internal bool PerformControlValidation(bool bulkValidation) { 

            // Skip validation for controls that don't support it 
            if (!this.CausesValidation) { 
                return false;
            } 

            // Raise the 'Validating' event. Stop now if handler cancels (ie. control is invalid).
            // NOTE: Handler may throw an exception here, but we must not attempt to catch it.
            if (this.NotifyValidating()) { 
                return true;
            } 
 
            // Raise the 'Validated' event. Handlers may throw exceptions here too - but
            // convert these to ThreadException events, unless the app is being debugged, 
            // or the control is being validated as part of a bulk validation operation.
            if (bulkValidation || NativeWindow.WndProcShouldBeDebuggable) {
                this.NotifyValidated();
            } 
            else {
                try { 
                    this.NotifyValidated(); 
                }
                catch (Exception e) { 
                    Application.OnThreadException(e);
                }
            }
 
            return false;
        } 
 
        /// 
        ///     Validates all the child controls in a container control. Exactly which controls are 
        ///     validated and which controls are skipped is determined by .
        ///     Return value indicates whether validation failed for any of the controls validated.
        ///     Calling function is responsible for checking the correctness of the validationConstraints argument.
        ///  
        /// 
        internal bool PerformContainerValidation(ValidationConstraints validationConstraints) { 
            bool failed = false; 

            // For every child control of this container control... 
            foreach (Control c in Controls) {

                // First, if the control is a container, recurse into its descendants.
                if ((validationConstraints & ValidationConstraints.ImmediateChildren) != ValidationConstraints.ImmediateChildren && 
                    c.ShouldPerformContainerValidation() &&
                    c.PerformContainerValidation(validationConstraints)) { 
                    failed = true; 
                }
 
                // Next, use input flags to decide whether to validate the control itself
                if ((validationConstraints & ValidationConstraints.Selectable) == ValidationConstraints.Selectable && !c.GetStyle(ControlStyles.Selectable) ||
                    (validationConstraints & ValidationConstraints.Enabled)    == ValidationConstraints.Enabled    && !c.Enabled ||
                    (validationConstraints & ValidationConstraints.Visible)    == ValidationConstraints.Visible    && !c.Visible || 
                    (validationConstraints & ValidationConstraints.TabStop)    == ValidationConstraints.TabStop    && !c.TabStop) {
                    continue; 
                } 

                // Finally, perform validation on the control itself 
                if (c.PerformControlValidation(true)) {
                    failed = true;
                }
            } 

            return failed; 
        } 

        ///  
        /// 
        ///     Computes the location of the screen point p in client coords.
        /// 
        public Point PointToClient(Point p) { 
            // Reviewed: The following demand has always been commented out since v1.0. In Whidbey, we have
            // re-reviewed this method to see if it needs protection, but haven't found any threats, so are 
            // going to keep it this way. See VSWhidbey #427555 for details. 
            //
            // Debug.WriteLineIf(IntSecurity.SecurityDemand.TraceVerbose, "ScreenLocationOfThings Demanded"); 
            // IntSecurity.ScreenLocationOfThings.Demand();
            return PointToClientInternal(p);
        }
        internal Point PointToClientInternal(Point p) { 
            // ASURT 42367.
            // Win9x reports incorrect values if you go outside the 16-bit range. 
            // We're not going to do anything about it, though -- it's esoteric, it clutters up the code, 
            // and potentially causes problems on systems that do support 32-bit coordinates.
 
            NativeMethods.POINT point = new NativeMethods.POINT(p.X, p.Y);
            UnsafeNativeMethods.MapWindowPoints(NativeMethods.NullHandleRef, new HandleRef(this, Handle), point, 1);
            return new Point(point.x, point.y);
        } 

        ///  
        ///  
        ///     Computes the location of the client point p in screen coords.
        ///  
        public Point PointToScreen(Point p) {
            // Reviewed: The following demand has always been commented out since v1.0. In Whidbey, we have
            // re-reviewed this method to see if it needs protection, but haven't found any threats, so are
            // going to keep it this way. See VSWhidbey #427555 for details. 
            //
            // Debug.WriteLineIf(IntSecurity.SecurityDemand.TraceVerbose, "ScreenLocationOfThings Demanded"); 
            // IntSecurity.ScreenLocationOfThings.Demand(); 

            NativeMethods.POINT point = new NativeMethods.POINT(p.X, p.Y); 
            UnsafeNativeMethods.MapWindowPoints(new HandleRef(this, Handle), NativeMethods.NullHandleRef, point, 1);
            return new Point(point.x, point.y);
        }
 
        /// 
        ///  
        ///      
        ///     This method is called by the application's message loop to pre-process
        ///     input messages before they are dispatched. Possible values for the 
        ///     msg.message field are WM_KEYDOWN, WM_SYSKEYDOWN, WM_CHAR, and WM_SYSCHAR.
        ///     If this method processes the message it must return true, in which case
        ///     the message loop will not dispatch the message.
        ///      
        ///     
        /// For WM_KEYDOWN and WM_SYSKEYDOWN messages, preProcessMessage() first 
        ///     calls processCmdKey() to check for command keys such as accelerators and 
        ///     menu shortcuts. If processCmdKey() doesn't process the message, then
        ///     isInputKey() is called to check whether the key message represents an 
        ///     input key for the control. Finally, if isInputKey() indicates that the
        ///     control isn't interested in the key message, then processDialogKey() is
        ///     called to check for dialog keys such as TAB, arrow keys, and mnemonics.
        ///      
        ///     
        /// For WM_CHAR messages, preProcessMessage() first calls isInputChar() to 
        ///     check whether the character message represents an input character for 
        ///     the control. If isInputChar() indicates that the control isn't interested
        ///     in the character message, then processDialogChar() is called to check for 
        ///     dialog characters such as mnemonics.
        ///     
        ///     
        /// For WM_SYSCHAR messages, preProcessMessage() calls processDialogChar() 
        ///     to check for dialog characters such as mnemonics.
        ///      
        ///      
        /// When overriding preProcessMessage(), a control should return true to
        ///     indicate that it has processed the message. For messages that aren't 
        ///     processed by the control, the result of "base.preProcessMessage()"
        ///     should be returned. Controls will typically override one of the more
        ///     specialized methods (isInputChar(), isInputKey(), processCmdKey(),
        ///     processDialogChar(), or processDialogKey()) instead of overriding 
        ///     preProcessMessage().
        ///      
        ///  
        [SecurityPermission(SecurityAction.InheritanceDemand, Flags=SecurityPermissionFlag.UnmanagedCode),
         SecurityPermission(SecurityAction.LinkDemand, Flags=SecurityPermissionFlag.UnmanagedCode)] 
        public virtual bool PreProcessMessage(ref Message msg) {
         //   Debug.WriteLineIf(ControlKeyboardRouting.TraceVerbose, "Control.PreProcessMessage " + msg.ToString());

            bool ret; 

            if (msg.Msg == NativeMethods.WM_KEYDOWN || msg.Msg == NativeMethods.WM_SYSKEYDOWN) { 
                if (!GetState2(STATE2_UICUES)) { 
                    ProcessUICues(ref msg);
                } 

                Keys keyData = (Keys)(unchecked((int)(long)msg.WParam) | (int)ModifierKeys);
                if (ProcessCmdKey(ref msg, keyData)) {
                    ret = true; 
                }
                else if (IsInputKey(keyData)) { 
                    SetState2(STATE2_INPUTKEY, true); 
                    ret = false;
                } 
                else {
                    // SECREVIEW : ProcessDialogKey can generate a call to ContainerControl.SetActiveControl which demands ModifyFocus permission,
                    //             we need to assert it here; the assert is safe, setting the active control does not expose any sec vulnerability
                    //             indirectly. 
                    //
                    IntSecurity.ModifyFocus.Assert(); 
                    try { 
                        ret = ProcessDialogKey(keyData);
                    } 
                    finally {
                        CodeAccessPermission.RevertAssert();
                    }
                } 
            }
            else if (msg.Msg == NativeMethods.WM_CHAR || msg.Msg == NativeMethods.WM_SYSCHAR) { 
                if (msg.Msg == NativeMethods.WM_CHAR && IsInputChar((char)msg.WParam)) { 
                    SetState2(STATE2_INPUTCHAR, true);
                    ret = false; 
                }
                else {
                    ret = ProcessDialogChar((char)msg.WParam);
                } 
            }
            else { 
                ret = false; 
            }
 
            return ret;
        }

        [EditorBrowsable(EditorBrowsableState.Advanced), 
         SecurityPermission(SecurityAction.LinkDemand, Flags=SecurityPermissionFlag.UnmanagedCode),
         SuppressMessage("Microsoft.Naming", "CA1702:CompoundWordsShouldBeCasedCorrectly"), 
         SuppressMessage("Microsoft.Performance", "CA1801:AvoidUnusedParameters"), 
         SuppressMessage("Microsoft.Design", "CA1045:DoNotPassTypesByReference")]  // using ref is OK.
        public PreProcessControlState PreProcessControlMessage(ref Message msg) { 
            return PreProcessControlMessageInternal(null, ref msg);
        }

        ///  
        ///  This method is similar to PreProcessMessage, but instead of indicating
        ///  that the message was either processed or it wasn't, it has three return 
        ///  values: 
        ///
        ///         MessageProcessed - PreProcessMessage() returns true, and the message 
        ///                            needs no further processing
        ///
        ///         MessageNeeded    - PreProcessMessage() returns false, but IsInputKey/Char
        ///                            return true.  This means the message wasn't processed, 
        ///                            but the control is interested in it.
        /// 
        ///         MessageNotNeeded - PreProcessMessage() returns false, and IsInputKey/Char 
        ///                            return false.
        ///  
        [SuppressMessage("Microsoft.Security", "CA2122:DoNotIndirectlyExposeMethodsWithLinkDemands")]
        internal static PreProcessControlState PreProcessControlMessageInternal(Control target, ref Message msg) {
            if (target == null) {
                target = Control.FromChildHandleInternal(msg.HWnd); 
            }
 
            if (target == null) { 
                return PreProcessControlState.MessageNotNeeded;
            } 

            // reset state that is used to make sure IsInputChar, IsInputKey and
            // ProcessUICues are not called multiple times.
            // ISSUE: Which control should these state bits be set on? probably the target. 
            target.SetState2(STATE2_INPUTKEY,  false);
            target.SetState2(STATE2_INPUTCHAR, false); 
            target.SetState2(STATE2_UICUES,    true); 

            Debug.WriteLineIf(ControlKeyboardRouting.TraceVerbose, "Control.PreProcessControlMessageInternal " + msg.ToString()); 

            try {
                Keys keyData = (Keys)(unchecked((int)(long)msg.WParam) | (int)ModifierKeys);
 
                // Allow control to preview key down message.
                if (msg.Msg == NativeMethods.WM_KEYDOWN || msg.Msg == NativeMethods.WM_SYSKEYDOWN) { 
                    target.ProcessUICues(ref msg); 

                    PreviewKeyDownEventArgs args = new PreviewKeyDownEventArgs(keyData); 
                    target.OnPreviewKeyDown(args);

                    if (args.IsInputKey) {
                        Debug.WriteLineIf(ControlKeyboardRouting.TraceVerbose, "PreviewKeyDown indicated this is an input key."); 
                        // Control wants this message - indicate it should be dispatched.
                        return PreProcessControlState.MessageNeeded; 
                    } 
                }
 
                PreProcessControlState state = PreProcessControlState.MessageNotNeeded;

                if (!target.PreProcessMessage(ref msg)) {
                    if (msg.Msg == NativeMethods.WM_KEYDOWN || msg.Msg == NativeMethods.WM_SYSKEYDOWN) { 

                        // check if IsInputKey has already procssed this message 
                        // or if it is safe to call - we only want it to be called once. 
                        if (target.GetState2(STATE2_INPUTKEY) || target.IsInputKey(keyData)) {
                            Debug.WriteLineIf(ControlKeyboardRouting.TraceVerbose, "Control didn't preprocess this message but it needs to be dispatched"); 
                            state = PreProcessControlState.MessageNeeded;
                        }
                    }
                    else if (msg.Msg == NativeMethods.WM_CHAR || msg.Msg == NativeMethods.WM_SYSCHAR) { 

                        // check if IsInputChar has already procssed this message 
                        // or if it is safe to call - we only want it to be called once. 
                        if (target.GetState2(STATE2_INPUTCHAR) || target.IsInputChar((char)msg.WParam)) {
                            Debug.WriteLineIf(ControlKeyboardRouting.TraceVerbose, "Control didn't preprocess this message but it needs to be dispatched"); 
                            state = PreProcessControlState.MessageNeeded;
                        }
                    }
                } 
                else {
                    state = PreProcessControlState.MessageProcessed; 
                } 

                return state; 
            }
            finally {
                target.SetState2(STATE2_UICUES, false);
            } 
        }
 
        ///  
        /// 
        ///      
        ///     Processes a command key. This method is called during message
        ///     pre-processing to handle command keys. Command keys are keys that always
        ///     take precedence over regular input keys. Examples of command keys
        ///     include accelerators and menu shortcuts. The method must return true to 
        ///     indicate that it has processed the command key, or false to indicate
        ///     that the key is not a command key. 
        ///      
        ///     
        /// processCmdKey() first checks if the control has a context menu, and if 
        ///     so calls the menu's processCmdKey() to check for menu shortcuts. If the
        ///     command key isn't a menu shortcut, and if the control has a parent, the
        ///     key is passed to the parent's processCmdKey() method. The net effect is
        ///     that command keys are "bubbled" up the control hierarchy. 
        ///     
        ///      
        /// When overriding processCmdKey(), a control should return true to 
        ///     indicate that it has processed the key. For keys that aren't processed by
        ///     the control, the result of "base.processCmdKey()" should be returned. 
        ///     
        ///     
        /// Controls will seldom, if ever, need to override this method.
        ///      
        /// 
        [ 
            SecurityPermission(SecurityAction.LinkDemand, Flags=SecurityPermissionFlag.UnmanagedCode), 
            SecurityPermission(SecurityAction.InheritanceDemand, Flags=SecurityPermissionFlag.UnmanagedCode)
        ] 
        protected virtual bool ProcessCmdKey(ref Message msg, Keys keyData) {
            Debug.WriteLineIf(ControlKeyboardRouting.TraceVerbose, "Control.ProcessCmdKey " + msg.ToString());
            ContextMenu contextMenu = (ContextMenu)Properties.GetObject(PropContextMenu);
            if (contextMenu != null && contextMenu.ProcessCmdKey(ref msg, keyData, this)) { 
                return true;
            } 
 
            if (parent != null) {
                return parent.ProcessCmdKey(ref msg, keyData); 
            }
            return false;

        } 

        private void PrintToMetaFile(HandleRef hDC, IntPtr lParam) { 
            Debug.Assert(UnsafeNativeMethods.GetObjectType(hDC) == NativeMethods.OBJ_ENHMETADC, 
                "PrintToMetaFile() called with a non-Enhanced MetaFile DC.");
            Debug.Assert(((long) lParam & NativeMethods.PRF_CHILDREN) != 0, 
                "PrintToMetaFile() called without PRF_CHILDREN.");

            // Strip the PRF_CHILDREN flag.  We will manually walk our children and print them.
            lParam = (IntPtr)((long) lParam & ~NativeMethods.PRF_CHILDREN); 

            // We're the root contol, so we need to set up our clipping region.  Retrieve the 
            // x-coordinates and y-coordinates of the viewport origin for the specified device context. 
            NativeMethods.POINT viewportOrg = new NativeMethods.POINT();
            bool success = SafeNativeMethods.GetViewportOrgEx(hDC, viewportOrg); 
            Debug.Assert(success, "GetViewportOrgEx() failed.");

            HandleRef hClippingRegion = new HandleRef(null, SafeNativeMethods.CreateRectRgn(viewportOrg.x,viewportOrg.y, viewportOrg.x + this.Width, viewportOrg.y + this.Height));
            Debug.Assert(hClippingRegion.Handle != IntPtr.Zero, "CreateRectRgn() failed."); 

            try { 
                // Select the new clipping region; make sure it's a SIMPLEREGION or NULLREGION 
                NativeMethods.RegionFlags selectResult = (NativeMethods.RegionFlags)SafeNativeMethods.SelectClipRgn(hDC, hClippingRegion);
                Debug.Assert((selectResult == NativeMethods.RegionFlags.SIMPLEREGION || 
                              selectResult == NativeMethods.RegionFlags.NULLREGION),
                              "SIMPLEREGION or NULLLREGION expected.");

                PrintToMetaFileRecursive(hDC, lParam, new Rectangle(Point.Empty, this.Size)); 
            }
            finally { 
                success = SafeNativeMethods.DeleteObject(hClippingRegion); 
                Debug.Assert(success, "DeleteObject() failed.");
            } 
        }

        internal virtual void PrintToMetaFileRecursive(HandleRef hDC, IntPtr lParam, Rectangle bounds) {
            // We assume the target does not want us to offset the root control in the metafile. 

            using (WindowsFormsUtils.DCMapping mapping = new WindowsFormsUtils.DCMapping(hDC, bounds)) { 
                // print the non-client area 
                PrintToMetaFile_SendPrintMessage(hDC, (IntPtr)((long)lParam & ~NativeMethods.PRF_CLIENT));
 
                // figure out mapping for the client area
                NativeMethods.RECT windowRect = new NativeMethods.RECT();
                bool success = UnsafeNativeMethods.GetWindowRect(new HandleRef(null, this.Handle), ref windowRect);
                Debug.Assert(success, "GetWindowRect() failed."); 
                Point clientOffset = PointToScreen(Point.Empty);
                clientOffset = new Point(clientOffset.X - windowRect.left, clientOffset.Y - windowRect.top); 
                Rectangle clientBounds = new Rectangle(clientOffset, ClientSize); 

                using (WindowsFormsUtils.DCMapping clientMapping = new WindowsFormsUtils.DCMapping(hDC, clientBounds)) { 
                    // print the client area
                    PrintToMetaFile_SendPrintMessage(hDC, (IntPtr)((long)lParam & ~NativeMethods.PRF_NONCLIENT));

                    // Paint children in reverse Z-Order 
                    int count = Controls.Count;
                    for (int i = count - 1; i >= 0; i--) { 
                        Control child = Controls[i]; 
                        if(child.Visible) {
                            child.PrintToMetaFileRecursive(hDC, lParam, child.Bounds); 
                        }
                    }
                }
            } 
        }
 
        private void PrintToMetaFile_SendPrintMessage(HandleRef hDC, IntPtr lParam) { 
            if(GetStyle(ControlStyles.UserPaint)) {
                // We let user paint controls paint directly into the metafile 
                SendMessage(NativeMethods.WM_PRINT, hDC.Handle, lParam);
            }
            else {
                // If a system control has no children in the Controls collection we 
                // restore the the PRF_CHILDREN flag because it may internally
                // have nested children we do not know about.  ComboBox is a 
                // good example. 
                if(Controls.Count == 0) {
                    lParam = (IntPtr)((long) lParam | NativeMethods.PRF_CHILDREN); 
                }

                // System controls must be painted into a temporary bitmap
                // which is then copied into the metafile.  (Old GDI line drawing 
                // is 1px thin, which causes borders to disappear, etc.)
                using (MetafileDCWrapper dcWrapper = new MetafileDCWrapper(hDC, this.Size)) { 
                    SendMessage(NativeMethods.WM_PRINT, dcWrapper.HDC, lParam); 
                }
            } 
        }

        /// 
        ///  
        ///     
        ///     Processes a dialog character. This method is called during message 
        ///     pre-processing to handle dialog characters, such as control mnemonics. 
        ///     This method is called only if the isInputChar() method indicates that
        ///     the control isn't interested in the character. 
        ///     
        ///     
        /// processDialogChar() simply sends the character to the parent's
        ///     processDialogChar() method, or returns false if the control has no 
        ///     parent. The Form class overrides this method to perform actual
        ///     processing of dialog characters. 
        ///      
        ///     
        /// When overriding processDialogChar(), a control should return true to 
        ///     indicate that it has processed the character. For characters that aren't
        ///     processed by the control, the result of "base.processDialogChar()"
        ///     should be returned.
        ///      
        ///     
        /// Controls will seldom, if ever, need to override this method. 
        ///      
        /// 
        [UIPermission(SecurityAction.InheritanceDemand, Window=UIPermissionWindow.AllWindows)] 
        [UIPermission(SecurityAction.LinkDemand, Window=UIPermissionWindow.AllWindows)]
        protected virtual bool ProcessDialogChar(char charCode) {
            Debug.WriteLineIf(ControlKeyboardRouting.TraceVerbose, "Control.ProcessDialogChar [" + charCode.ToString() + "]");
            return parent == null? false: parent.ProcessDialogChar(charCode); 
        }
 
        ///  
        /// 
        ///      
        ///     Processes a dialog key. This method is called during message
        ///     pre-processing to handle dialog characters, such as TAB, RETURN, ESCAPE,
        ///     and arrow keys. This method is called only if the isInputKey() method
        ///     indicates that the control isn't interested in the key. 
        ///     
        ///      
        /// processDialogKey() simply sends the character to the parent's 
        ///     processDialogKey() method, or returns false if the control has no
        ///     parent. The Form class overrides this method to perform actual 
        ///     processing of dialog keys.
        ///     
        ///     
        /// When overriding processDialogKey(), a control should return true to 
        ///     indicate that it has processed the key. For keys that aren't processed
        ///     by the control, the result of "base.processDialogKey(...)" should be 
        ///     returned. 
        ///     
        ///      
        /// Controls will seldom, if ever, need to override this method.
        ///     
        /// 
        [UIPermission(SecurityAction.InheritanceDemand, Window=UIPermissionWindow.AllWindows)] 
        [UIPermission(SecurityAction.LinkDemand, Window=UIPermissionWindow.AllWindows)]
        protected virtual bool ProcessDialogKey(Keys keyData) { 
            Debug.WriteLineIf(ControlKeyboardRouting.TraceVerbose, "Control.ProcessDialogKey " + keyData.ToString()); 
            return parent == null? false: parent.ProcessDialogKey(keyData);
        } 

        /// 
        /// 
        ///      
        ///     Processes a key message. This method is called when a control receives a
        ///     keyboard message. The method is responsible for generating the appropriate 
        ///     key events for the message by calling OnKeyPress(), onKeyDown(), or 
        ///     onKeyUp(). The m parameter contains the window message that must
        ///     be processed. Possible values for the m.msg field are WM_CHAR, 
        ///     WM_KEYDOWN, WM_SYSKEYDOWN, WM_KEYUP, WM_SYSKEYUP, and WM_IMECHAR.
        ///     
        ///     
        /// When overriding processKeyEventArgs(), a control should return true to 
        ///     indicate that it has processed the key. For keys that aren't processed
        ///     by the control, the result of "base.processKeyEventArgs()" should be 
        ///     returned. 
        ///     
        ///      
        /// Controls will seldom, if ever, need to override this method.
        ///     
        /// 
        [ 
            SecurityPermission(SecurityAction.LinkDemand, Flags=SecurityPermissionFlag.UnmanagedCode),
            SecurityPermission(SecurityAction.InheritanceDemand, Flags=SecurityPermissionFlag.UnmanagedCode) 
        ] 
        protected virtual bool ProcessKeyEventArgs(ref Message m) {
            Debug.WriteLineIf(ControlKeyboardRouting.TraceVerbose, "Control.ProcessKeyEventArgs " + m.ToString()); 
            KeyEventArgs ke = null;
            KeyPressEventArgs kpe = null;
            IntPtr newWParam = IntPtr.Zero;
 
            if (m.Msg == NativeMethods.WM_CHAR || m.Msg == NativeMethods.WM_SYSCHAR) {
                int charsToIgnore = this.ImeWmCharsToIgnore; 
 
                if (charsToIgnore > 0) {
                    charsToIgnore--; 
                    Debug.WriteLineIf(CompModSwitches.ImeMode.Level >= TraceLevel.Info, "charsToIgnore decreased, new val = " + charsToIgnore + ", this=" + this);

                    this.ImeWmCharsToIgnore = charsToIgnore;
                    return false; 
                }
                else { 
                    kpe = new KeyPressEventArgs(unchecked((char)(long)m.WParam)); 
                    OnKeyPress(kpe);
                    newWParam = (IntPtr) kpe.KeyChar; 
                }
            }
            else if (m.Msg == NativeMethods.WM_IME_CHAR) {
                int charsToIgnore = this.ImeWmCharsToIgnore; 

                if (Marshal.SystemDefaultCharSize == 1) { 
                    // On Win9X we get either an SBCS or an  MBCS value. We must convert it to 
                    // UNICODE to use in the KeyPressEventArg.
                    // 
                    // VSWhidbey 145962: Convert the character in this message to UNICODE
                    // for use in the KeyPress event, but then convert it back from UNICODE
                    // to its source value for processing in the DefWindowProc, which will expect a
                    // non-UNICODE character. 
                    char unicodeChar = (char)0;
                    byte[] b = new byte[] {(byte)(unchecked((int)(long)m.WParam) >> 8), unchecked((byte)(long)m.WParam)}; 
                    char[] unicodeCharArray = new char[1]; 
                    int stringLength = UnsafeNativeMethods.MultiByteToWideChar(0 /*CP_ACP*/, UnsafeNativeMethods.MB_PRECOMPOSED, b, b.Length, unicodeCharArray, 0);
                    if (stringLength > 0) { 
                        unicodeCharArray = new char[stringLength];
                        UnsafeNativeMethods.MultiByteToWideChar(0 /*CP_ACP*/, UnsafeNativeMethods.MB_PRECOMPOSED, b, b.Length, unicodeCharArray, unicodeCharArray.Length);

                        // Per the docs for WM_IME_CHAR, the processing of this message by DefWindowProc 
                        // will produce two WM_CHAR messages if the character value is a DBCS character.
                        // Otherwise, only one WM_CHAR message will be generated. Therefore, only ignore 
                        // one WM_CHAR message for SBCS characters and two WM_CHAR messages for DBCS 
                        // characters.
 
                        // What type of character were we passed?
                        if (unicodeCharArray[0] != 0) {
                            // This was an MBCS character, so pass along the first character
                            // from the resultant array. 
                            unicodeChar = unicodeCharArray[0];
 
                            charsToIgnore += 2; 
                        }
                        else if (unicodeCharArray[0] == 0 && unicodeCharArray.Length >= 2) { 
                            // This was an SBCS character, so pass along the second character
                            // from the resultant array since the first character in the array is NULL.
                            unicodeChar = unicodeCharArray[1];
 
                            charsToIgnore += 1;
                        } 
                    } 
                    else {
                        //MultiByteToWideChar failed 
                        throw new Win32Exception();
                    }

                    this.ImeWmCharsToIgnore = charsToIgnore; 

                    // 
                    kpe = new KeyPressEventArgs(unicodeChar); 
                }
                else { 
                    charsToIgnore += (3 - Marshal.SystemDefaultCharSize);
                    this.ImeWmCharsToIgnore = charsToIgnore;

                    kpe = new KeyPressEventArgs(unchecked((char)(long)m.WParam)); 
                }
 
                char preEventCharacter = kpe.KeyChar; 
                OnKeyPress(kpe);
 
                //If the character wasn't changed, just use the original value rather than round tripping.
                if (kpe.KeyChar == preEventCharacter) {
                    newWParam = m.WParam;
                } 
                else {
                    if (Marshal.SystemDefaultCharSize == 1) { 
                        // VSWhidbey 145962: On Win9X we work with either an SBCS or an MBCS value. Since we 
                        // already converted it to UNICODE to send it to the KeyPress event, we must now convert
                        // it back to either MBCS or SBCS for processing by the DefWindowProc. 
                        //
                        string keyChar = new string(new char[] { kpe.KeyChar });
                        byte[] mbcsBytes = null;
                        int bytesNeeded = UnsafeNativeMethods.WideCharToMultiByte(0 /*CP_ACP*/, 0, keyChar, keyChar.Length, null, 0, IntPtr.Zero, IntPtr.Zero); 
                        // GB18030 defines 4 byte characters: we shouldn't assume that the length is capped at 2.
                        if (bytesNeeded >= 2) { 
                            // This is an MBCS character. 
                            mbcsBytes = new byte[bytesNeeded];
                            UnsafeNativeMethods.WideCharToMultiByte(0 /*CP_ACP*/, 0, keyChar, keyChar.Length, mbcsBytes, mbcsBytes.Length, IntPtr.Zero, IntPtr.Zero); 

                            int sizeOfIntPtr = Marshal.SizeOf(typeof(IntPtr));
                            if (bytesNeeded > sizeOfIntPtr) {
                                bytesNeeded = sizeOfIntPtr; //Same again: we wouldn't be able to stuff anything larger into a WParam 
                            }
                            long wParam = 0; 
                            for (int i = 0; i < bytesNeeded; i++) { 
                                wParam <<= 8;
                                wParam |= (long)mbcsBytes[i]; 
                            }
                            newWParam = (IntPtr)wParam;
                        }
                        else if (bytesNeeded == 1) { 
                            // This is an SBCS character.
                            mbcsBytes = new byte[bytesNeeded]; 
                            UnsafeNativeMethods.WideCharToMultiByte(0 /*CP_ACP*/, 
                                                                    0,
                                                                    keyChar, 
                                                                    keyChar.Length,
                                                                    mbcsBytes,
                                                                    mbcsBytes.Length,
                                                                    IntPtr.Zero, 
                                                                    IntPtr.Zero);
                            newWParam = (IntPtr)((int)mbcsBytes[0]); 
                        } 
                        else {
                            //We don't know what's going on: WideCharToMultiByte failed.  We can't deal with that. 
                            newWParam = m.WParam;
                        }
                    }
                    else { 
                        newWParam = (IntPtr)kpe.KeyChar;
                    } 
                } 
            }
            else { 
                ke = new KeyEventArgs((Keys)(unchecked((int)(long)m.WParam)) | ModifierKeys);
                if (m.Msg == NativeMethods.WM_KEYDOWN || m.Msg == NativeMethods.WM_SYSKEYDOWN) {
                    OnKeyDown(ke);
                } 
                else {
                    OnKeyUp(ke); 
                } 
            }
 
            if (kpe != null) {
                Debug.WriteLineIf(ControlKeyboardRouting.TraceVerbose, "    processkeyeventarg returning: " + kpe.Handled);
                m.WParam = newWParam;
                return kpe.Handled; 
            }
            else { 
                Debug.WriteLineIf(ControlKeyboardRouting.TraceVerbose, "    processkeyeventarg returning: " + ke.Handled); 
                if (ke.SuppressKeyPress) {
                    RemovePendingMessages(NativeMethods.WM_CHAR,     NativeMethods.WM_CHAR); 
                    RemovePendingMessages(NativeMethods.WM_SYSCHAR,  NativeMethods.WM_SYSCHAR);
                    RemovePendingMessages(NativeMethods.WM_IME_CHAR, NativeMethods.WM_IME_CHAR);
                }
                return ke.Handled; 
            }
        } 
 
        /// 
        ///  
        ///     Processes a key message. This method is called when a control receives a
        ///     keyboard message. The method first checks if the control has a parent,
        ///     and if so calls the parent's processKeyPreview() method. If the parent's
        ///     processKeyPreview() method doesn't consume the message then 
        ///     processKeyEventArgs() is called to generate the appropriate keyboard events.
        ///     The m parameter contains the window message that must be 
        ///     processed. Possible values for the m.msg field are WM_CHAR, 
        ///     WM_KEYDOWN, WM_SYSKEYDOWN, WM_KEYUP, and WM_SYSKEYUP.
        /// When overriding processKeyMessage(), a control should return true to 
        ///     indicate that it has processed the key. For keys that aren't processed
        ///     by the control, the result of "base.processKeyMessage()" should be
        ///     returned.
        /// Controls will seldom, if ever, need to override this method. 
        /// 
        [ 
            SecurityPermission(SecurityAction.LinkDemand, Flags=SecurityPermissionFlag.UnmanagedCode), 
            SecurityPermission(SecurityAction.InheritanceDemand, Flags=SecurityPermissionFlag.UnmanagedCode)
        ] 
        protected internal virtual bool ProcessKeyMessage(ref Message m) {
            Debug.WriteLineIf(ControlKeyboardRouting.TraceVerbose, "Control.ProcessKeyMessage " + m.ToString());
            if (parent != null && parent.ProcessKeyPreview(ref m)) return true;
            return ProcessKeyEventArgs(ref m); 
        }
 
        ///  
        /// 
        ///      
        ///     Previews a keyboard message. This method is called by a child control
        ///     when the child control receives a keyboard message. The child control
        ///     calls this method before generating any keyboard events for the message.
        ///     If this method returns true, the child control considers the message 
        ///     consumed and does not generate any keyboard events. The m
        ///     parameter contains the window message to preview. Possible values for 
        ///     the m.msg field are WM_CHAR, WM_KEYDOWN, WM_SYSKEYDOWN, WM_KEYUP, 
        ///     and WM_SYSKEYUP.
        ///      
        ///     
        /// processKeyPreview() simply sends the character to the parent's
        ///     processKeyPreview() method, or returns false if the control has no
        ///     parent. The Form class overrides this method to perform actual 
        ///     processing of dialog keys.
        ///      
        ///      
        /// When overriding processKeyPreview(), a control should return true to
        ///     indicate that it has processed the key. For keys that aren't processed 
        ///     by the control, the result of "base.ProcessKeyPreview(...)" should be
        ///     returned.
        ///     
        ///  
        [
            SecurityPermission(SecurityAction.LinkDemand, Flags=SecurityPermissionFlag.UnmanagedCode), 
            SecurityPermission(SecurityAction.InheritanceDemand, Flags=SecurityPermissionFlag.UnmanagedCode) 
        ]
        protected virtual bool ProcessKeyPreview(ref Message m) { 
            Debug.WriteLineIf(ControlKeyboardRouting.TraceVerbose, "Control.ProcessKeyPreview " + m.ToString());
            return parent == null? false: parent.ProcessKeyPreview(ref m);
        }
 
        /// 
        ///  
        ///      
        ///     Processes a mnemonic character. This method is called to give a control
        ///     the opportunity to process a mnemonic character. The method should check 
        ///     if the control is in a state to process mnemonics and if the given
        ///     character represents a mnemonic. If so, the method should perform the
        ///     action associated with the mnemonic and return true. If not, the method
        ///     should return false. 
        ///     
        ///      
        /// Implementations of this method often use the isMnemonic() method to 
        ///     check if the given character matches a mnemonic in the control's text,
        ///     for example: 
        /// 
        ///     if (canSelect() && isMnemonic(charCode, getText()) {
        ///     // perform action associated with mnemonic
        ///     } 
        /// 
        ///      
        ///      
        /// This default implementation of processMnemonic() simply returns false
        ///     to indicate that the control has no mnemonic. 
        ///     
        /// 
        [UIPermission(SecurityAction.InheritanceDemand, Window=UIPermissionWindow.AllWindows)]
        [UIPermission(SecurityAction.LinkDemand, Window=UIPermissionWindow.AllWindows)] 
        protected internal virtual bool ProcessMnemonic(char charCode) {
#if DEBUG 
            Debug.WriteLineIf(ControlKeyboardRouting.TraceVerbose, "Control.ProcessMnemonic [0x" + ((int)charCode).ToString("X", CultureInfo.InvariantCulture) + "]"); 
#endif
            return false; 
        }

         /// 
         ///     Preprocess keys which affect focus indicators and keyboard cues. 
         /// 
         internal void ProcessUICues(ref Message msg) { 
             Keys keyCode = (Keys)((int)msg.WParam) & Keys.KeyCode; 

             if (keyCode != Keys.F10 && keyCode != Keys.Menu && keyCode != Keys.Tab) { 
                 return;  // PERF: dont WM_QUERYUISTATE if we dont have to.
             }

             Control topMostParent = null; 
             int current = unchecked( (int) (long)SendMessage(NativeMethods.WM_QUERYUISTATE, 0, 0));
 
             // VSWhidbey 536248 - dont trust when a control says the accelerators are showing. 
             // make sure the topmost parent agrees with this as we could be in a mismatched state.
             if (current == 0 /*accelerator and focus cues are showing*/) { 
                 topMostParent = this.TopMostParent;
                 current = (int)topMostParent.SendMessage(NativeMethods.WM_QUERYUISTATE, 0, 0);
             }
             int toClear = 0; 

            // if we are here, a key or tab has been pressed on this control. 
            // now that we know the state of accelerators, check to see if we need 
            // to show them.  NOTE: due to the strangeness of the API we OR in
            // the opposite of what we want to do.  So if we want to show accelerators, 
            // we OR in UISF_HIDEACCEL, then call UIS_CLEAR to clear the "hidden" state.

             if (keyCode == Keys.F10 || keyCode == Keys.Menu) {
                 if ((current & NativeMethods.UISF_HIDEACCEL) != 0) { 
                     // Keyboard accelerators are hidden, they need to be shown
                     toClear |= NativeMethods.UISF_HIDEACCEL; 
                 } 
             }
 
             if (keyCode == Keys.Tab) {
                 if ((current & NativeMethods.UISF_HIDEFOCUS) != 0) {
                     // Focus indicators are hidden, they need to be shown
                     toClear |= NativeMethods.UISF_HIDEFOCUS; 
                 }
             } 
 
             if (toClear != 0) {
                 // We've detected some state we need to unset, usually clearing the hidden state of 
                 // the accelerators.  We need to get the topmost parent and call CHANGEUISTATE so
                 // that the entire tree of controls is
                 if (topMostParent == null) {
                     topMostParent = this.TopMostParent; 
                 }
 
                 // VSWhidbey 434901,362408 
                 // A) if we're parented to a native dialog - REFRESH our child states ONLY
                 //       Then we've got to send a WM_UPDATEUISTATE to the topmost managed control (which will be non-toplevel) 
                 //           (we assume here the root native window has changed UI state, and we're not to manage the UI state for it)
                 //
                 // B) if we're totally managed - CHANGE the root window state AND REFRESH our child states.
                 //       Then we've got to send a WM_CHANGEUISTATE to the topmost managed control (which will be toplevel) 
                 //       According to MSDN, WM_CHANGEUISTATE will generate WM_UPDATEUISTATE messages for all immediate children (via DefWndProc)
                 //           (we're in charge here, we've got to change the state of the root window) 
                 UnsafeNativeMethods.SendMessage( 
                     new HandleRef(topMostParent, topMostParent.Handle),
                     UnsafeNativeMethods.GetParent(new HandleRef(null, topMostParent.Handle)) == IntPtr.Zero ? NativeMethods.WM_CHANGEUISTATE : NativeMethods.WM_UPDATEUISTATE, 
                     (IntPtr)(NativeMethods.UIS_CLEAR | (toClear << 16)),
                     IntPtr.Zero);
             }
         } 

        ///  
        ///  
        ///     Raises the event associated with key with the event data of
        ///     e and a sender of this control. 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected void RaiseDragEvent(Object key, DragEventArgs e) {
            DragEventHandler handler = (DragEventHandler)Events[key]; 
            if (handler != null) handler(this, e);
        } 
 
        /// 
        ///  
        ///     Raises the event associated with key with the event data of
        ///     e and a sender of this control.
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected void RaisePaintEvent(Object key, PaintEventArgs e) {
            PaintEventHandler handler = (PaintEventHandler)Events[EventPaint]; 
            if (handler != null) handler(this, e); 
        }
 
        private void RemovePendingMessages(int msgMin, int msgMax) {
            if (!this.IsDisposed) {
                NativeMethods.MSG msg = new NativeMethods.MSG();
                IntPtr hwnd = this.Handle; 
                while (UnsafeNativeMethods.PeekMessage(ref msg, new HandleRef(this, hwnd),
                                                       msgMin, msgMax, 
                                                       NativeMethods.PM_REMOVE)) { 
                    ; // NULL loop
                } 
            }
        }

        ///  
        /// 
        ///     Resets the back color to be based on the parent's back color. 
        ///  
        [EditorBrowsable(EditorBrowsableState.Never)]
        public virtual void ResetBackColor() { 
            BackColor = Color.Empty;
        }

        ///  
        /// 
        ///    [To be supplied.] 
        ///  
        [EditorBrowsable(EditorBrowsableState.Never)]
        public virtual void ResetCursor() { 
            Cursor = null;
        }

        private void ResetEnabled() { 
            Enabled = true;
        } 
 
        /// 
        ///  
        ///     Resets the font to be based on the parent's font.
        /// 
        [EditorBrowsable(EditorBrowsableState.Never)]
        public virtual void ResetFont() { 
            Font = null;
        } 
 
        /// 
        ///  
        ///     Resets the fore color to be based on the parent's fore color.
        /// 
        [EditorBrowsable(EditorBrowsableState.Never)]
        public virtual void ResetForeColor() { 
            ForeColor = Color.Empty;
        } 
 
        private void ResetLocation() {
            Location = new Point(0,0); 
        }

        private void ResetMargin() {
            Margin = DefaultMargin; 
        }
 
        private void ResetMinimumSize() { 
            MinimumSize = DefaultMinimumSize;
        } 

       private void ResetPadding() {
           CommonProperties.ResetPadding(this);
       } 

       private void ResetSize() { 
            Size = DefaultSize; 
       }
 
        /// 
        /// 
        ///     Resets the RightToLeft to be the default.
        ///  
        [EditorBrowsable(EditorBrowsableState.Never)]
        public virtual void ResetRightToLeft() { 
            RightToLeft = RightToLeft.Inherit; 
        }
 
        /// 
        /// 
        ///     Forces the recreation of the handle for this control. Inheriting controls
        ///     must call base.RecreateHandle. 
        /// 
        [ 
        EditorBrowsable(EditorBrowsableState.Advanced) 
        ]
        protected void RecreateHandle() { 
            RecreateHandleCore();
        }

        internal virtual void RecreateHandleCore() { 
            //
            lock(this) { 
                if (IsHandleCreated) { 

                    bool focused = ContainsFocus; 

#if DEBUG
                    if (CoreSwitches.PerfTrack.Enabled) {
                        Debug.Write("RecreateHandle: "); 
                        Debug.Write(GetType().FullName);
                        Debug.Write(" [Text="); 
                        Debug.Write(Text); 
                        Debug.Write("]");
                        Debug.WriteLine(""); 
                    }
#endif
                    bool created = (state & STATE_CREATED) != 0;
                    if (GetState(STATE_TRACKINGMOUSEEVENT)) { 
                        SetState(STATE_MOUSEENTERPENDING, true);
                        UnhookMouseEvent(); 
                    } 

                    HandleRef parentHandle = new HandleRef(this, UnsafeNativeMethods.GetParent(new HandleRef(this, this.Handle))); 

                    try {
                        Control [] controlSnapshot = null;
                        state |= STATE_RECREATE; 

                        try { 
 

                            // VSWhidbey 228656 RecreateHandle - destroy window destroys all children 
                            // Inform child controls that their parent is recreating handle.

                            // The default behavior is to now SetParent to parking window, then
                            // SetParent back after the parent's handle has been recreated. 
                            // This behavior can be overridden in OnParentHandleRecreat* and is in ListView.
 
                            //fish out control collection w/o demand creating one. 
                            ControlCollection controlsCollection = (ControlCollection)Properties.GetObject(PropControlsCollection);
                            if (controlsCollection != null && controlsCollection.Count > 0) { 
                                controlSnapshot = new Control[controlsCollection.Count];
                                for (int i = 0; i < controlsCollection.Count; i++) {
                                    Control childControl = controlsCollection[i];
                                    if (childControl != null && childControl.IsHandleCreated) { 
                                        // SetParent to parking window
                                        childControl.OnParentHandleRecreating(); 
 
                                        // if we were successful, remember this control
                                        // so we can raise OnParentHandleRecreated 
                                        controlSnapshot[i] = childControl;
                                    }
                                    else {
                                        // put in a null slot which we'll skip over later. 
                                        controlSnapshot[i] = null;
                                    } 
                                } 
                            }
 
                            // do the main work of recreating the handle
                            DestroyHandle();
                            CreateHandle();
                        } 
                        finally {
                            state &= ~STATE_RECREATE; 
 
                            // inform children that their parent's handle has recreated
                            if (controlSnapshot != null) { 
                                for (int i = 0; i < controlSnapshot.Length; i++) {
                                    Control childControl = controlSnapshot[i];
                                    if (childControl != null && childControl.IsHandleCreated) {
                                        // SetParent back to the new Parent handle 
                                        childControl.OnParentHandleRecreated();
                                    } 
                                } 
                            }
                        } 
                        if (created) {
                            CreateControl();
                        }
                    } 
                    finally {
                        if (parentHandle.Handle != IntPtr.Zero                               // the parent was not null 
                            && (Control.FromHandleInternal(parentHandle.Handle) == null || this.parent == null) // but wasnt a windows forms window 
                            && UnsafeNativeMethods.IsWindow(parentHandle)) {                 // and still is a window
                            // correctly parent back up to where we were before. 
                            // if we were parented to a proper windows forms control, CreateControl would have properly parented
                            // us back.
                            UnsafeNativeMethods.SetParent(new HandleRef(this, this.Handle), parentHandle);
                        } 
                    }
 
 
                    // Restore control focus
                    if (focused) { 
                        FocusInternal();
                    }
                }
            } 
        }
 
        ///  
        /// 
        ///     Computes the location of the screen rectangle r in client coords. 
        /// 
        public Rectangle RectangleToClient(Rectangle r) {
            // Reviewed: The following demand has always been commented out since v1.0. In Whidbey, we have
            // re-reviewed this method to see if it needs protection, but haven't found any threats, so are 
            // going to keep it this way. See VSWhidbey #427555 for details.
            // 
            // Debug.WriteLineIf(IntSecurity.SecurityDemand.TraceVerbose, "ScreenLocationOfThings Demanded"); 
            // IntSecurity.ScreenLocationOfThings.Demand();
 
            NativeMethods.RECT rect = NativeMethods.RECT.FromXYWH(r.X, r.Y, r.Width, r.Height);
            UnsafeNativeMethods.MapWindowPoints(NativeMethods.NullHandleRef, new HandleRef(this, Handle), ref rect, 2);
            return Rectangle.FromLTRB(rect.left, rect.top, rect.right, rect.bottom);
        } 

        ///  
        ///  
        ///     Computes the location of the client rectangle r in screen coords.
        ///  
        public Rectangle RectangleToScreen(Rectangle r) {
            // Reviewed: The following demand has always been commented out since v1.0. In Whidbey, we have
            // re-reviewed this method to see if it needs protection, but haven't found any threats, so are
            // going to keep it this way. See VSWhidbey #427555 for details. 
            //
            // Debug.WriteLineIf(IntSecurity.SecurityDemand.TraceVerbose, "ScreenLocationOfThings Demanded"); 
            // IntSecurity.ScreenLocationOfThings.Demand(); 

            NativeMethods.RECT rect = NativeMethods.RECT.FromXYWH(r.X, r.Y, r.Width, r.Height); 
            UnsafeNativeMethods.MapWindowPoints(new HandleRef(this, Handle), NativeMethods.NullHandleRef, ref rect, 2);
            return Rectangle.FromLTRB(rect.left, rect.top, rect.right, rect.bottom);
        }
 
        /// 
        ///  
        ///     Reflects the specified message to the control that is bound to hWnd. 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected static bool ReflectMessage(IntPtr hWnd, ref Message m) {
            Debug.WriteLineIf(IntSecurity.SecurityDemand.TraceVerbose, "SendMessages Demanded");
            IntSecurity.SendMessages.Demand();
            return ReflectMessageInternal(hWnd, ref m); 
        }
 
        // SECURITY WARNING: This method bypasses a security demand. Use with caution! 
        internal static bool ReflectMessageInternal(IntPtr hWnd, ref Message m) {
            Control control = Control.FromHandleInternal(hWnd); 
            if (control == null) return false;
            m.Result = control.SendMessage(NativeMethods.WM_REFLECT + m.Msg, m.WParam, m.LParam);
            return true;
        } 

        ///  
        ///  
        ///     Forces the control to invalidate and immediately
        ///     repaint itself and any children. 
        /// 
        public virtual void Refresh() {
            Invalidate(true);
            Update(); 
        }
 
        ///  
        /// 
        ///     Resets the mouse leave listeners. 
        /// 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected void ResetMouseEventArgs() { 
            if (GetState(STATE_TRACKINGMOUSEEVENT)) {
                UnhookMouseEvent(); 
                HookMouseEvent(); 
            }
        } 

        /// 
        /// 
        ///     Resets the text to it's default value. 
        /// 
        public virtual void ResetText() { 
            Text = String.Empty; 
        }
 
        private void ResetVisible() {
            Visible = true;
        }
 
        /// 
        ///  
        ///     Resumes normal layout logic. This will force a layout immediately 
        ///     if there are any pending layout requests.
        ///  
        public void ResumeLayout() {
            ResumeLayout(true);
        }
 
        /// 
        ///  
        ///     Resumes normal layout logic. If performLayout is set to true then 
        ///     this will force a layout immediately if there are any pending layout requests.
        ///  
        public void ResumeLayout(bool performLayout) {
#if DEBUG
            if (CompModSwitches.LayoutSuspendResume.TraceInfo) {
                Debug.WriteLine(GetType().Name + "::ResumeLayout( preformLayout = " + performLayout + ", newCount = " + Math.Max(0, layoutSuspendCount - 1) + ")"); 
            }
#endif 
            Debug.Assert(layoutSuspendCount > 0, "Unbalanance suspend/resume layout."); 

            bool performedLayout = false; 

            if (layoutSuspendCount > 0) {

                if (layoutSuspendCount == 1) { 
                    layoutSuspendCount++;
                    try { 
                        OnLayoutResuming(performLayout); 
                    }
                    finally { 
                        layoutSuspendCount--;
                    }
                }
 
                layoutSuspendCount--;
                if (layoutSuspendCount == 0 
                    && GetState(STATE_LAYOUTDEFERRED) 
                    && performLayout) {
                        PerformLayout(); 
                        performedLayout = true;
                }
            }
 

            // VSWhidbey 464817 - we need to be careful 
            // about which LayoutEventArgs are used in 
            // SuspendLayout, PerformLayout, ResumeLayout() sequences.
            // See bug for more info. 
            if (!performedLayout) {
                SetState2(STATE2_CLEARLAYOUTARGS, true);
            }
 

            /* 
 
            We've had this since Everett,but it seems wrong, redundant and a performance hit.  The
            correct layout calls are already made when bounds or parenting changes, which is all 
            we care about. We may want to call this at layout suspend count == 0, but certainaly
            not for all resumes.  I  tried removing it, and doing it only when suspendCount == 0,
            but we break things at every step.
 
            */
            if (!performLayout) { 
 
                CommonProperties.xClearPreferredSizeCache(this);
                ControlCollection controlsCollection = (ControlCollection)Properties.GetObject(PropControlsCollection); 

                // PERFNOTE: This is more efficient than using Foreach.  Foreach
                // forces the creation of an array subset enum each time we
                // enumerate 
                if (controlsCollection != null) {
                    for (int i = 0; i < controlsCollection.Count; i++) { 
                        LayoutEngine.InitLayout(controlsCollection[i], BoundsSpecified.All); 
                        CommonProperties.xClearPreferredSizeCache(controlsCollection[i]);
                    } 
                }
            }

        } 

        ///  
        ///     Used to actually register the control as a drop target. 
        /// 
        ///  
        internal void SetAcceptDrops(bool accept) {
            if (accept != GetState(STATE_DROPTARGET) && IsHandleCreated) {
                try {
                    if (Application.OleRequired() != System.Threading.ApartmentState.STA) { 
                        throw new ThreadStateException(SR.GetString(SR.ThreadMustBeSTA));
                    } 
                    if (accept) { 
                        IntSecurity.ClipboardRead.Demand();
 
                        Debug.WriteLineIf(CompModSwitches.DragDrop.TraceInfo, "Registering as drop target: " + Handle.ToString());
                        // Register
                        int n = UnsafeNativeMethods.RegisterDragDrop(new HandleRef(this, Handle), (UnsafeNativeMethods.IOleDropTarget)(new DropTarget(this)));
                        Debug.WriteLineIf(CompModSwitches.DragDrop.TraceInfo, "   ret:" + n.ToString(CultureInfo.CurrentCulture)); 
                        if (n != 0 && n != NativeMethods.DRAGDROP_E_ALREADYREGISTERED) {
                            throw new Win32Exception(n); 
                        } 
                    }
                    else { 
                        Debug.WriteLineIf(CompModSwitches.DragDrop.TraceInfo, "Revoking drop target: " + Handle.ToString());
                        // Revoke
                        int n = UnsafeNativeMethods.RevokeDragDrop(new HandleRef(this, Handle));
                        Debug.WriteLineIf(CompModSwitches.DragDrop.TraceInfo, "   ret:" + n.ToString(CultureInfo.InvariantCulture)); 
                        if (n != 0 && n != NativeMethods.DRAGDROP_E_NOTREGISTERED) {
                            throw new Win32Exception(n); 
                        } 
                    }
                    SetState(STATE_DROPTARGET, accept); 
                }
                catch (Exception e) {
                    throw new InvalidOperationException(SR.GetString(SR.DragDropRegFailed), e);
                } 
            }
        } 
 
        /// 
        ///  
        ///     Scales to entire control and any child controls.
        /// 
        [Obsolete("This method has been deprecated. Use the Scale(SizeF ratio) method instead. http://go.microsoft.com/fwlink/?linkid=14202")]
        [EditorBrowsable(EditorBrowsableState.Never)] 
        public void Scale(float ratio) {
            ScaleCore(ratio, ratio); 
        } 

        ///  
        /// 
        ///     Scales the entire control and any child controls.
        /// 
        [Obsolete("This method has been deprecated. Use the Scale(SizeF ratio) method instead. http://go.microsoft.com/fwlink/?linkid=14202")] 
        [EditorBrowsable(EditorBrowsableState.Never)]
        public void Scale(float dx, float dy) { 
#if DEBUG 
            int dbgLayoutCheck = LayoutSuspendCount;
#endif 
            SuspendLayout();
            try {
                ScaleCore(dx, dy);
            } 
            finally {
                ResumeLayout(); 
#if DEBUG 
                AssertLayoutSuspendCount(dbgLayoutCheck);
#endif 
            }
        }

        ///  
        /// 
        ///     Scales a control and its children given a scaling factor. 
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        public void Scale(SizeF factor) { 

            // VSWhidbey 501184:
            // manually call ScaleControl recursively instead of the internal scale method
            // when someone calls this method, they really do want to do some sort of 
            // zooming feature, as opposed to AutoScale.
            using (new LayoutTransaction(this, this, PropertyNames.Bounds, false)) { 
                ScaleControl(factor, factor, this); 
                if (ScaleChildren) {
                    ControlCollection controlsCollection = (ControlCollection)Properties.GetObject(PropControlsCollection); 
                    if (controlsCollection != null) {
                        // PERFNOTE: This is more efficient than using Foreach.  Foreach
                        // forces the creation of an array subset enum each time we
                        // enumerate 
                        for (int i = 0; i < controlsCollection.Count; i++) {
                            Control c = controlsCollection[i]; 
                            c.Scale(factor); 
                        }
                    } 
                }
            }

            LayoutTransaction.DoLayout(this, this, PropertyNames.Bounds); 

        } 
 
        /// 
        ///  
        ///     Scales a control and its children given a pair of scaling factors.
        ///     IncludedFactor will be applied to the dimensions of controls based on
        ///     their RequiredScaling property.  For example, if a control's
        ///     RequiredScaling property returns Width, the width of the control will 
        ///     be scaled according to the includedFactor value.
        /// 
        ///     The excludedFactor parameter is used to scale those control bounds who 
        ///     are not included in RequiredScaling.
        /// 
        ///     If a factor is empty, it indicates that no scaling of those control
        ///     dimensions should be done.
        ///
        ///     The requestingControl property indicates which control has requested 
        ///     the scaling function.
        ///  
        internal virtual void Scale(SizeF includedFactor, SizeF excludedFactor, Control requestingControl) { 
            // When we scale, we are establishing new baselines for the
            // positions of all controls.  Therefore, we should resume(false). 
            using (new LayoutTransaction(this, this, PropertyNames.Bounds, false)) {
                ScaleControl(includedFactor, excludedFactor, requestingControl);
                ScaleChildControls(includedFactor, excludedFactor, requestingControl);
            } 
            LayoutTransaction.DoLayout(this, this, PropertyNames.Bounds);
        } 
 
        /// 
        ///  
        ///     Scales the children of this control.  The default implementation recursively
        ///     walks children and calls ScaleControl on each one.
        ///     IncludedFactor will be applied to the dimensions of controls based on
        ///     their RequiredScaling property.  For example, if a control's 
        ///     RequiredScaling property returns Width, the width of the control will
        ///     be scaled according to the includedFactor value. 
        /// 
        ///     The excludedFactor parameter is used to scale those control bounds who
        ///     are not included in RequiredScaling. 
        ///
        ///     If a factor is empty, it indicates that no scaling of those control
        ///     dimensions should be done.
        /// 
        ///     The requestingControl property indicates which control has requested
        ///     the scaling function. 
        ///  
        internal void ScaleChildControls(SizeF includedFactor, SizeF excludedFactor, Control requestingControl) {
 
            if (ScaleChildren) {
                ControlCollection controlsCollection = (ControlCollection)Properties.GetObject(PropControlsCollection);

                if (controlsCollection != null) { 
                    // PERFNOTE: This is more efficient than using Foreach.  Foreach
                    // forces the creation of an array subset enum each time we 
                    // enumerate 
                    for (int i = 0; i < controlsCollection.Count; i++) {
                        Control c = controlsCollection[i]; 
                        c.Scale(includedFactor, excludedFactor, requestingControl);
                    }
                }
            } 
        }
 
        ///  
        ///     Scales the children of this control.  The default implementation walks the controls
        ///     collection for the control and calls Scale on each control. 
        ///     IncludedFactor will be applied to the dimensions of controls based on
        ///     their RequiredScaling property.  For example, if a control's
        ///     RequiredScaling property returns Width, the width of the control will
        ///     be scaled according to the includedFactor value. 
        ///
        ///     The excludedFactor parameter is used to scale those control bounds who 
        ///     are not included in RequiredScaling. 
        ///
        ///     If a factor is empty, it indicates that no scaling of those control 
        ///     dimensions should be done.
        ///
        ///     The requestingControl property indicates which control has requested
        ///     the scaling function. 
        /// 
        internal void ScaleControl(SizeF includedFactor, SizeF excludedFactor, Control requestingControl) { 
            BoundsSpecified includedSpecified = BoundsSpecified.None; 
            BoundsSpecified excludedSpecified = BoundsSpecified.None;
 
            if (!includedFactor.IsEmpty) {
                includedSpecified = RequiredScaling;
            }
 
            if (!excludedFactor.IsEmpty) {
                excludedSpecified |= (~RequiredScaling & BoundsSpecified.All); 
            } 
#if DEBUG
            if (CompModSwitches.RichLayout.TraceInfo) { 
                Debug.WriteLine(string.Format(CultureInfo.InvariantCulture, "Scaling {0} Included: {1}, Excluded: {2}",
                                  this, includedFactor, excludedFactor));
            }
#endif 

            if (includedSpecified != BoundsSpecified.None) { 
                ScaleControl(includedFactor, includedSpecified); 
            }
 
            if (excludedSpecified != BoundsSpecified.None) {
                ScaleControl(excludedFactor, excludedSpecified);
            }
 
            if (!includedFactor.IsEmpty) {
                RequiredScaling = BoundsSpecified.None; 
            } 
        }
 
        /// 
        /// 
        ///     Scales an individual control's location, size, padding and margin.
        ///     If the control is top level, this will not scale the control's location. 
        ///     This does not scale children or the size of auto sized controls.  You can
        ///     omit scaling in any direction by changing BoundsSpecified. 
        /// 
        ///     After the control is scaled the RequiredScaling property is set to
        ///     BoundsSpecified.None. 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void ScaleControl(SizeF factor, BoundsSpecified specified) {
 

            CreateParams cp = CreateParams; 
            NativeMethods.RECT adornments = new NativeMethods.RECT(0, 0, 0, 0); 
            SafeNativeMethods.AdjustWindowRectEx(ref adornments, cp.Style, HasMenu, cp.ExStyle);
            Size minSize = MinimumSize; 
            Size maxSize = MaximumSize;

            // VSWhidbey 412836
            // clear out min and max size, otherwise this could affect the scaling logic. 
            MinimumSize = Size.Empty;
            MaximumSize = Size.Empty; 
 
            // this is raw because Min/Max size have been cleared at this point.
            Rectangle rawScaledBounds = GetScaledBounds(Bounds, factor, specified); 

            //
            // Scale Padding and Margin
            // 
            float dx = factor.Width;
            float dy = factor.Height; 
 
            Padding padding = Padding;
            Padding margins = Margin; 

            // Clear off specified bits for 1.0 scaling factors
            if (dx == 1.0F) specified &= ~(BoundsSpecified.X | BoundsSpecified.Width);
            if (dy == 1.0F) specified &= ~(BoundsSpecified.Y | BoundsSpecified.Height); 

            if (dx != 1.0F) { 
                padding.Left = (int)Math.Round(padding.Left * dx); 
                padding.Right = (int)Math.Round(padding.Right * dx);
                margins.Left = (int)Math.Round(margins.Left * dx); 
                margins.Right = (int)Math.Round(margins.Right * dx);
            }

            if (dy != 1.0F) { 
                padding.Top = (int)Math.Round(padding.Top * dy);
                padding.Bottom = (int)Math.Round(padding.Bottom * dy); 
                margins.Top = (int)Math.Round(margins.Top * dy); 
                margins.Bottom = (int)Math.Round(margins.Bottom * dy);
            } 

            // Apply padding and margins
            Padding = padding;
            Margin = margins; 

            // 
            // Scale Min/Max size 
            //
 
            // VSWhidbey 412836
            // make sure we consider the andornments as fixed.  rather than scaling the entire size,
            // we should pull out the fixed things such as the border, scale the rest, then apply the fixed
            // adornment size. 
            Size adornmentSize = adornments.Size;
            if (!minSize.IsEmpty) { 
                minSize -= adornmentSize; 
                minSize = ScaleSize(LayoutUtils.UnionSizes(Size.Empty, minSize), // make sure we dont go below 0.
                                        factor.Width, 
                                        factor.Height) + adornmentSize;
            }
            if (!maxSize.IsEmpty) {
                maxSize -= adornmentSize; 
                maxSize = ScaleSize(LayoutUtils.UnionSizes(Size.Empty, maxSize), // make sure we dont go below 0.
                                        factor.Width, 
                                        factor.Height) + adornmentSize; 
            }
 

            // Apply the min/max size constraints - dont call ApplySizeConstraints
            // as MinimumSize/MaximumSize are currently cleared out.
            Size maximumSize = LayoutUtils.ConvertZeroToUnbounded(maxSize); 
            Size scaledSize = LayoutUtils.IntersectSizes(rawScaledBounds.Size, maximumSize);
            scaledSize = LayoutUtils.UnionSizes(scaledSize, minSize); 
 
            // Set in the scaled bounds as constrained by the newly scaled min/max size.
            SetBoundsCore(rawScaledBounds.X, rawScaledBounds.Y, scaledSize.Width, scaledSize.Height, BoundsSpecified.All); 

            MaximumSize = maxSize;
            MinimumSize = minSize;
 

        } 
 

        ///  
        /// 
        ///     Performs the work of scaling the entire control and any child controls.
        /// 
        [EditorBrowsable(EditorBrowsableState.Never)] 
        protected virtual void ScaleCore(float dx, float dy) {
            Debug.WriteLineIf(CompModSwitches.RichLayout.TraceInfo, GetType().Name + "::ScaleCore(" + dx + ", " + dy + ")"); 
#if DEBUG 
            int dbgLayoutCheck = LayoutSuspendCount;
#endif 
            SuspendLayout();
            try {
                int sx = (int)Math.Round(x * dx);
                int sy = (int)Math.Round(y * dy); 

                int sw = width; 
                if ((controlStyle & ControlStyles.FixedWidth) != ControlStyles.FixedWidth) { 
                    sw = (int)(Math.Round((x + width) * dx)) - sx;
                } 
                int sh = height;
                if ((controlStyle & ControlStyles.FixedHeight) != ControlStyles.FixedHeight) {
                    sh = (int)(Math.Round((y + height) * dy)) - sy;
                } 

                SetBounds(sx, sy, sw, sh, BoundsSpecified.All); 
 
                ControlCollection controlsCollection = (ControlCollection)Properties.GetObject(PropControlsCollection);
 
                if (controlsCollection != null) {
                    // PERFNOTE: This is more efficient than using Foreach.  Foreach
                    // forces the creation of an array subset enum each time we
                    // enumerate 
                    for (int i = 0; i < controlsCollection.Count; i++) {
#pragma warning disable 618 
                        controlsCollection[i].Scale(dx, dy); 
#pragma warning restore 618
                    } 
                }
            }
            finally {
                ResumeLayout(); 
#if DEBUG
                AssertLayoutSuspendCount(dbgLayoutCheck); 
#endif 
            }
        } 

        /// 
        ///     Scales a given size with the provided values.
        ///  
        internal Size ScaleSize(Size startSize, float x, float y) {
            Size size = startSize; 
            if (!GetStyle(ControlStyles.FixedWidth)) { 
                size.Width = (int)Math.Round((float)size.Width * x);
            } 
            if (!GetStyle(ControlStyles.FixedHeight)) {
                size.Height = (int)Math.Round((float)size.Height * y);
            }
            return size; 
        }
 
        ///  
        /// 
        ///     Activates this control. 
        /// 
        public void Select() {
            Select(false, false);
        } 

        // used by Form 
        ///  
        /// 
        ///    [To be supplied.] 
        /// 
        protected virtual void Select(bool directed, bool forward) {
            IContainerControl c = GetContainerControlInternal();
 
            if (c != null) {
                c.ActiveControl = this; 
            } 
        }
 
        /// 
        /// 
        ///     Selects the next control following ctl.
        ///  
        public bool SelectNextControl(Control ctl, bool forward, bool tabStopOnly, bool nested, bool wrap) {
            if (!Contains(ctl) || !nested && ctl.parent != this) ctl = null; 
 
            bool alreadyWrapped = false;
            Control start = ctl; 
            do {
                ctl = GetNextControl(ctl, forward);
                if (ctl == null) {
                    if (!wrap) break; 
                    if (alreadyWrapped) {
                        return false; //VSWhidbey 423098 prevent infinite wrapping. 
                    } 
                    alreadyWrapped = true;
                } 
                else {
                    if (ctl.CanSelect
                        && (!tabStopOnly || ctl.TabStop)
                        && (nested || ctl.parent == this)) { 

                        ctl.Select(true, forward); 
                        return true; 
                    }
                } 
            } while (ctl != start);
            return false;
        }
 

        ///  
        ///     Unsafe internal version of SelectNextControl - Use with caution! 
        /// 
        internal bool SelectNextControlInternal(Control ctl, bool forward, bool tabStopOnly, bool nested, bool wrap) { 
            IntSecurity.ModifyFocus.Assert();
            return SelectNextControl(ctl, forward, tabStopOnly, nested, wrap);
        }
 
        /// 
        ///     This is called recursively when visibility is changed for a control, this 
        ///     forces focus to be moved to a visible control. 
        /// 
        private void SelectNextIfFocused() { 
            // V#32437 - We want to move focus away from hidden controls, so this
            //           function was added.
            //
            if (ContainsFocus && ParentInternal != null) { 
                IContainerControl c = ParentInternal.GetContainerControlInternal();
 
                if (c != null) { 
                    // SECREVIEW : Control.SelectNextControl generates a call to ContainerControl.ActiveControl which demands
                    //             ModifyFocus permission, the demand is to prevent DOS attacks but it doesn't expose a sec 
                    //             vulnerability indirectly.  So it is safe to call the internal version of SelectNextControl here.
                    //
                    ((Control)c).SelectNextControlInternal(this, true, true, true, true);
                } 
            }
        } 
 
        /// 
        ///     Sends a Win32 message to this control.  If the control does not yet 
        ///     have a handle, it will be created.
        /// 
        internal IntPtr SendMessage(int msg, int wparam, int lparam) {
            Debug.Assert(IsHandleCreated, "Performance alert!  Calling Control::SendMessage and forcing handle creation.  Re-work control so handle creation is not required to set properties.  If there is no work around, wrap the call in an IsHandleCreated check."); 
            return UnsafeNativeMethods.SendMessage(new HandleRef(this, Handle), msg, wparam, lparam);
        } 
 
        /// 
        ///     Sends a Win32 message to this control.  If the control does not yet 
        ///     have a handle, it will be created.
        /// 
        internal IntPtr SendMessage(int msg, ref int wparam, ref int lparam) {
            Debug.Assert(IsHandleCreated, "Performance alert!  Calling Control::SendMessage and forcing handle creation.  Re-work control so handle creation is not required to set properties.  If there is no work around, wrap the call in an IsHandleCreated check."); 
            return UnsafeNativeMethods.SendMessage(new HandleRef(this, Handle), msg, ref wparam, ref lparam);
        } 
        internal IntPtr SendMessage(int msg, int wparam, IntPtr lparam) { 
            Debug.Assert(IsHandleCreated, "Performance alert!  Calling Control::SendMessage and forcing handle creation.  Re-work control so handle creation is not required to set properties.  If there is no work around, wrap the call in an IsHandleCreated check.");
            return UnsafeNativeMethods.SendMessage(new HandleRef(this, Handle), msg, (IntPtr)wparam, lparam); 
        }

        internal IntPtr SendMessage(int msg, IntPtr wparam, IntPtr lparam) {
            Debug.Assert(IsHandleCreated, "Performance alert!  Calling Control::SendMessage and forcing handle creation.  Re-work control so handle creation is not required to set properties.  If there is no work around, wrap the call in an IsHandleCreated check."); 
            return UnsafeNativeMethods.SendMessage(new HandleRef(this, Handle), msg, wparam, lparam);
        } 
 
        internal IntPtr SendMessage(int msg, IntPtr wparam, int lparam) {
            Debug.Assert(IsHandleCreated, "Performance alert!  Calling Control::SendMessage and forcing handle creation.  Re-work control so handle creation is not required to set properties.  If there is no work around, wrap the call in an IsHandleCreated check."); 
            return UnsafeNativeMethods.SendMessage(new HandleRef(this, Handle), msg, wparam, (IntPtr)lparam);
        }

        ///  
        ///     Sends a Win32 message to this control.  If the control does not yet
        ///     have a handle, it will be created. 
        ///  
        internal IntPtr SendMessage(int msg, int wparam, ref NativeMethods.RECT lparam) {
            Debug.Assert(IsHandleCreated, "Performance alert!  Calling Control::SendMessage and forcing handle creation.  Re-work control so handle creation is not required to set properties.  If there is no work around, wrap the call in an IsHandleCreated check."); 
            return UnsafeNativeMethods.SendMessage(new HandleRef(this, Handle), msg, wparam, ref lparam);
        }

        ///  
        ///     Sends a Win32 message to this control.  If the control does not yet
        ///     have a handle, it will be created. 
        ///  
        internal IntPtr SendMessage(int msg, bool wparam, int lparam) {
            Debug.Assert(IsHandleCreated, "Performance alert!  Calling Control::SendMessage and forcing handle creation.  Re-work control so handle creation is not required to set properties.  If there is no work around, wrap the call in an IsHandleCreated check."); 
            return UnsafeNativeMethods.SendMessage(new HandleRef(this, Handle), msg, wparam, lparam);
        }

        ///  
        ///     Sends a Win32 message to this control.  If the control does not yet
        ///     have a handle, it will be created. 
        ///  
        internal IntPtr SendMessage(int msg, int wparam, string lparam) {
            Debug.Assert(IsHandleCreated, "Performance alert!  Calling Control::SendMessage and forcing handle creation.  Re-work control so handle creation is not required to set properties.  If there is no work around, wrap the call in an IsHandleCreated check."); 
            return UnsafeNativeMethods.SendMessage(new HandleRef(this, Handle), msg, wparam, lparam);
        }
        /// 
        ///  
        ///     sends this control to the back of the z-order
        ///  
        public void SendToBack() { 
            if (parent != null) {
                parent.Controls.SetChildIndex(this, -1); 
            }
            else if (IsHandleCreated && GetTopLevel()) {
                SafeNativeMethods.SetWindowPos(new HandleRef(window, Handle), NativeMethods.HWND_BOTTOM, 0, 0, 0, 0,
                                               NativeMethods.SWP_NOMOVE | NativeMethods.SWP_NOSIZE); 
            }
 
        } 

        ///  
        /// 
        ///     Sets the bounds of the control.
        /// 
        public void SetBounds(int x, int y, int width, int height) { 
            if (this.x != x || this.y != y || this.width != width ||
                this.height != height) { 
                SetBoundsCore(x, y, width, height, BoundsSpecified.All); 

                // WM_WINDOWPOSCHANGED will trickle down to an OnResize() which will 
                // have refreshed the interior layout.  We only need to layout the parent.
                LayoutTransaction.DoLayout(ParentInternal, this, PropertyNames.Bounds);
            }
            else { 
                // Still need to init scaling.
                InitScaling(BoundsSpecified.All); 
            } 
        }
 
        /// 
        /// 
        ///     Sets the bounds of the control.
        ///  
        public void SetBounds(int x, int y, int width, int height, BoundsSpecified specified) {
            if ((specified & BoundsSpecified.X) == BoundsSpecified.None) x = this.x; 
            if ((specified & BoundsSpecified.Y) == BoundsSpecified.None) y = this.y; 
            if ((specified & BoundsSpecified.Width) == BoundsSpecified.None) width = this.width;
            if ((specified & BoundsSpecified.Height) == BoundsSpecified.None) height = this.height; 
            if (this.x != x || this.y != y || this.width != width ||
                this.height != height) {
                SetBoundsCore(x, y, width, height, specified);
 
                // WM_WINDOWPOSCHANGED will trickle down to an OnResize() which will
                // have refreshed the interior layout or the resized control.  We only need to layout 
                // the parent.  This happens after InitLayout has been invoked. 
                LayoutTransaction.DoLayout(ParentInternal, this, PropertyNames.Bounds);
            } 
            else {
                // Still need to init scaling.
                InitScaling(specified);
            } 
        }
 
        ///  
        /// 
        ///     Performs the work of setting the bounds of this control. Inheriting 
        ///     classes can overide this function to add size restrictions. Inheriting
        ///     classes must call base.setBoundsCore to actually cause the bounds
        ///     of the control to change.
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected virtual void SetBoundsCore(int x, int y, int width, int height, BoundsSpecified specified) { 
#if DEBUG 
            if (CompModSwitches.SetBounds.TraceInfo) {
                Debug.WriteLine(String.Format(CultureInfo.CurrentCulture, "{0}::SetBoundsCore(x={1} y={2} width={3} height={4} specified={5}", Name, x, y, width, height, specified)); 
            }
#endif
            // SetWindowPos below sends a WmWindowPositionChanged (not posts) so we immediately
            // end up in WmWindowPositionChanged which may cause the parent to layout.  We need to 
            // suspend/resume to defer the parent from laying out until after InitLayout has been called
            // to update the layout engine's state with the new control bounds. 
#if DEBUG 
            int suspendCount = -44371;      // Arbitrary negative prime to surface bugs.
#endif 
            if (ParentInternal != null) {
#if DEBUG
                suspendCount = ParentInternal.LayoutSuspendCount;
#endif 
                ParentInternal.SuspendLayout();
            } 
            try { 
                if (this.x != x || this.y != y || this.width != width || this.height != height) {
                    CommonProperties.UpdateSpecifiedBounds(this, x, y, width, height, specified); 

                    // Provide control with an opportunity to apply self imposed constraints on its size.
                    Rectangle adjustedBounds = ApplyBoundsConstraints(x,y, width, height);
                    width = adjustedBounds.Width; 
                    height = adjustedBounds.Height;
                    x = adjustedBounds.X; 
                    y = adjustedBounds.Y; 

                    if (!IsHandleCreated) { 
                        // Handle is not created, just record our new position and we're done.
                        UpdateBounds(x, y, width, height);
                    } else {
                        if (!GetState(STATE_SIZELOCKEDBYOS)) { 
                            int flags = NativeMethods.SWP_NOZORDER | NativeMethods.SWP_NOACTIVATE;
 
                            if (this.x == x && this.y == y) { 
                                flags |= NativeMethods.SWP_NOMOVE;
                            } 
                            if (this.width == width && this.height == height) {
                                flags |= NativeMethods.SWP_NOSIZE;
                            }
 
                            //
                            // Give a chance for derived controls to do what they want, just before we resize. 
                            OnBoundsUpdate(x, y, width, height); 

                            SafeNativeMethods.SetWindowPos(new HandleRef(window, Handle), NativeMethods.NullHandleRef, x, y, width, height, flags); 

                            // NOTE: SetWindowPos causes a WM_WINDOWPOSCHANGED which is processed
                            // synchonously so we effectively end up in UpdateBounds immediately following
                            // SetWindowPos. 
                            //
                            //UpdateBounds(x, y, width, height); 
                        } 
                    }
                } 
            }
            finally {

                // Initialize the scaling engine. 
                InitScaling(specified);
 
                if (ParentInternal != null) { 
                    // Some layout engines (DefaultLayout) base their PreferredSize on
                    // the bounds of their children.  If we change change the child bounds, we 
                    // need to clear their PreferredSize cache.  The semantics of SetBoundsCore
                    // is that it does not cause a layout, so we just clear.
                    CommonProperties.xClearPreferredSizeCache(ParentInternal);
 
                    // Cause the current control to initialize its layout (e.g., Anchored controls
                    // memorize their distance from their parent's edges).  It is your parent's 
                    // LayoutEngine which manages your layout, so we call into the parent's 
                    // LayoutEngine.
                    ParentInternal.LayoutEngine.InitLayout(this, specified); 
                    ParentInternal.ResumeLayout( /* performLayout = */ true );
#if DEBUG
                    Debug.Assert(ParentInternal.LayoutSuspendCount == suspendCount, "Suspend/Resume layout mismatch!");
#endif 
                }
            } 
        } 

        ///  
        /// 
        ///     Performs the work of setting the size of the client area of the control.
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual void SetClientSizeCore(int x, int y) {
            Size = SizeFromClientSize(x, y); 
            clientWidth = x; 
            clientHeight = y;
            OnClientSizeChanged(EventArgs.Empty); 
        }

        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected virtual Size SizeFromClientSize(Size clientSize) {
            return SizeFromClientSize(clientSize.Width, clientSize.Height); 
        } 

        internal Size SizeFromClientSize(int width, int height) { 
            NativeMethods.RECT rect = new NativeMethods.RECT(0, 0, width, height);
            CreateParams cp = CreateParams;
            SafeNativeMethods.AdjustWindowRectEx(ref rect, cp.Style, HasMenu, cp.ExStyle);
            return rect.Size; 
        }
 
        private void SetHandle(IntPtr value) { 
            if (value == IntPtr.Zero) {
                SetState(STATE_CREATED, false); 
            }
            UpdateRoot();
        }
 
        private void SetParentHandle(IntPtr value) {
            Debug.Assert(value != NativeMethods.InvalidIntPtr, "Outdated call to SetParentHandle"); 
 
            if (IsHandleCreated) {
                IntPtr parentHandle = UnsafeNativeMethods.GetParent(new HandleRef(window, Handle)); 
                bool topLevel = GetTopLevel();
                if (parentHandle != value || (parentHandle == IntPtr.Zero && !topLevel)) {
                    Debug.Assert(Handle != value, "Cycle created in SetParentHandle");
 
                    bool recreate = (parentHandle == IntPtr.Zero && !topLevel)
                        || (value == IntPtr.Zero && topLevel); 
 
                    if (recreate) {
                        // We will recreate later, when the MdiChild's visibility 
                        // is set to true (see bug 124232)
                        Form f = this as Form;
                        if (f != null) {
                            if (!f.CanRecreateHandle()) { 
                                recreate = false;
                                // we don't want to recreate - but our styles may have changed. 
                                // before we unpark the window below we need to update 
                                UpdateStyles();
                            } 
                        }
                    }

                    if (recreate) { 
                        RecreateHandle();
                    } 
                    if (!GetTopLevel()) { 
                        if (value == IntPtr.Zero) {
                            Application.ParkHandle(new HandleRef(window, Handle)); 
                            UpdateRoot();
                        }
                        else {
                            UnsafeNativeMethods.SetParent(new HandleRef(window, Handle), new HandleRef(null, value)); 
                            if (parent != null) {
                                parent.UpdateChildZOrder(this); 
                            } 
                            Application.UnparkHandle(new HandleRef(window, Handle));
                        } 
                    }
                }
                else if (value == IntPtr.Zero && parentHandle == IntPtr.Zero && topLevel) {
                    // See VSWhidbey 531685: The handle was previously parented to the parking window. Its TopLevel property was 
                    // then changed to true so the above call to GetParent returns null even though the parent of the control is
                    // not null. We need to explicitly set the parent to null. 
                    UnsafeNativeMethods.SetParent(new HandleRef(window, Handle), new HandleRef(null, IntPtr.Zero)); 
                    Application.UnparkHandle(new HandleRef(window, Handle));
                } 
            }
        }

        // Form, UserControl, AxHost usage 
        internal void SetState(int flag, bool value) {
            state = value? state | flag: state & ~flag; 
        } 

        // Application, SKWindow usage 
        internal void SetState2(int flag, bool value) {
            state2 = value ? state2 | flag : state2 & ~flag;
        }
 
        /// 
        ///  
        ///     Sets the current value of the specified bit in the control's style. 
        ///     NOTE: This is control style, not the Win32 style of the hWnd.
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected void SetStyle(ControlStyles flag, bool value) {
            // WARNING: if we ever add argument checking to "flag", we will need
            // to move private styles like Layered to State. 
            // ASURT: 151576 Calling SetStyle(ControlStyles.EnableNotifyMessage,...) should require UnmanagedCode
            if ((flag & ControlStyles.EnableNotifyMessage) != 0 && value) 
            { 
                // demand security permission for this condition.
                // this will throw security exception in semi-trust. 
                IntSecurity.UnmanagedCode.Demand();
            }
            controlStyle = value? controlStyle | flag: controlStyle & ~flag;
        } 

        internal static IntPtr SetUpPalette(IntPtr dc, bool force, bool realizePalette) { 
            Debug.WriteLineIf(Control.PaletteTracing.TraceVerbose, "SetUpPalette(force:=" + force + ", ralizePalette:=" + realizePalette + ")"); 

            IntPtr halftonePalette = Graphics.GetHalftonePalette(); 

            Debug.WriteLineIf(Control.PaletteTracing.TraceVerbose, "select palette " + !force);
            IntPtr result = SafeNativeMethods.SelectPalette(new HandleRef(null, dc), new HandleRef(null, halftonePalette), (force ? 0 : 1));
 
            if (result != IntPtr.Zero && realizePalette) {
                SafeNativeMethods.RealizePalette(new HandleRef(null, dc)); 
            } 

            return result; 
        }

        /// 
        ///  
        ///    [To be supplied.]
        ///  
        protected void SetTopLevel(bool value) { 
            if (value && IsActiveX) {
                throw new InvalidOperationException(SR.GetString(SR.TopLevelNotAllowedIfActiveX)); 
            }
            else {
                if (value) {
                    if (this is Form) { 
                        Debug.WriteLineIf(IntSecurity.SecurityDemand.TraceVerbose, "TopLevelWindow Demanded");
                        IntSecurity.TopLevelWindow.Demand(); 
                    } 
                    else {
                        Debug.WriteLineIf(IntSecurity.SecurityDemand.TraceVerbose, "UnrestrictedWindows Demanded"); 
                        IntSecurity.UnrestrictedWindows.Demand();
                    }
                }
 
                SetTopLevelInternal(value);
            } 
        } 

        // SECURITY WARNING: This method bypasses a security demand. Use with caution! 
        internal void SetTopLevelInternal(bool value) {

            if (GetTopLevel() != value) {
                if (parent != null) { 
                    throw new ArgumentException(SR.GetString(SR.TopLevelParentedControl), "value");
                } 
                SetState(STATE_TOPLEVEL, value); 
                // VSWhidbey 476889: make sure the handle is created before hooking, otherwise a toplevel control that never
                // creates its handle will leak. 
                if (IsHandleCreated && GetState2(STATE2_INTERESTEDINUSERPREFERENCECHANGED)) {
                    ListenToUserPreferenceChanged(value);
                }
                UpdateStyles(); 
                SetParentHandle(IntPtr.Zero);
                if (value && Visible) { 
                    CreateControl(); 
                }
                UpdateRoot(); 
            }
        }

        ///  
        /// 
        ///    [To be supplied.] 
        ///  
        protected virtual void SetVisibleCore(bool value) {
            try { 
                System.Internal.HandleCollector.SuspendCollect();

                if (GetVisibleCore() != value) {
                    if (!value) { 
                        SelectNextIfFocused();
                    } 
 
                    bool fireChange = false;
 
                    if (GetTopLevel()) {

                        // The processing of WmShowWindow will set the visibility
                        // bit and call CreateControl() 
                        //
                        if (IsHandleCreated || value) { 
                                SafeNativeMethods.ShowWindow(new HandleRef(this, Handle), value ? ShowParams : NativeMethods.SW_HIDE); 
                        }
                    } 
                    else if (IsHandleCreated || value && parent != null && parent.Created) {

                        // We want to mark the control as visible so that CreateControl
                        // knows that we are going to be displayed... however in case 
                        // an exception is thrown, we need to back the change out.
                        // 
                        SetState(STATE_VISIBLE, value); 
                        fireChange = true;
                        try { 
                            if (value) CreateControl();
                            SafeNativeMethods.SetWindowPos(new HandleRef(window, Handle),
                                                           NativeMethods.NullHandleRef,
                                                           0, 0, 0, 0, 
                                                           NativeMethods.SWP_NOSIZE
                                                           | NativeMethods.SWP_NOMOVE 
                                                           | NativeMethods.SWP_NOZORDER 
                                                           | NativeMethods.SWP_NOACTIVATE
                                                           | (value ? NativeMethods.SWP_SHOWWINDOW : NativeMethods.SWP_HIDEWINDOW)); 
                        }
                        catch {
                            SetState(STATE_VISIBLE, !value);
                            throw; 
                        }
                    } 
                    if (GetVisibleCore() != value) { 
                        SetState(STATE_VISIBLE, value);
                        fireChange = true; 
                    }

                    if (fireChange) {
                        // We do not do this in the OnPropertyChanged event for visible 
                        // Lots of things could cause us to become visible, including a
                        // parent window.  We do not want to indescriminiately layout 
                        // due to this, but we do want to layout if the user changed 
                        // our visibility.
                        // 

                        using (new LayoutTransaction(parent, this, PropertyNames.Visible)) {
                            OnVisibleChanged(EventArgs.Empty);
                        } 
                    }
                    UpdateRoot(); 
                } 
                else { // value of Visible property not changed, but raw bit may have
 
                    if (!GetState(STATE_VISIBLE) && !value && IsHandleCreated) {
                        // PERF - setting Visible=false twice can get us into this else block
                        // which makes us process WM_WINDOWPOS* messages - make sure we've already
                        // visible=false - if not, make it so. 
                         if (!SafeNativeMethods.IsWindowVisible(new HandleRef(this,this.Handle))) {
                            // we're already invisible - bail. 
                            return; 
                         }
                    } 

                    SetState(STATE_VISIBLE, value);

                    // If the handle is already created, we need to update the window style. 
                    // This situation occurs when the parent control is not currently visible,
                    // but the child control has already been created. 
                    // 
                    if (IsHandleCreated) {
 
                        SafeNativeMethods.SetWindowPos(
                                                          new HandleRef(window, Handle), NativeMethods.NullHandleRef, 0, 0, 0, 0, NativeMethods.SWP_NOSIZE |
                                                          NativeMethods.SWP_NOMOVE | NativeMethods.SWP_NOZORDER | NativeMethods.SWP_NOACTIVATE |
                                                          (value ? NativeMethods.SWP_SHOWWINDOW : NativeMethods.SWP_HIDEWINDOW)); 
                    }
                } 
            } 
            finally {
                System.Internal.HandleCollector.ResumeCollect(); 
            }
        }

        ///  
        /// 
        ///     Determine effective auto-validation setting for a given control, based on the AutoValidate property 
        ///     of its containing control. Defaults to 'EnablePreventFocusChange' if there is no containing control 
        ///     (eg. because this control is a top-level container).
        ///  
        /// 
        internal static AutoValidate GetAutoValidateForControl(Control control) {
            ContainerControl parent = control.ParentContainerControl;
            return (parent != null) ? parent.AutoValidate : AutoValidate.EnablePreventFocusChange; 
        }
 
        ///  
        /// 
        ///     Is auto-validation currently in effect for this control? 
        ///     Depends on the AutoValidate property of the containing control.
        /// 
        /// 
        [EditorBrowsable(EditorBrowsableState.Never)] 
        internal bool ShouldAutoValidate {
            get { 
                return GetAutoValidateForControl(this) != AutoValidate.Disable; 
            }
        } 

        // Refer vsW: 543074: This method is called in PerformContainerValidation to check if this control supports containerValidation.
        // TabControl overrides this method to return true.
        internal virtual bool ShouldPerformContainerValidation() { 
            return GetStyle(ControlStyles.ContainerControl);
        } 
 
        /// 
        ///  
        ///     Returns true if the backColor should be persisted in code gen.
        /// 
        [EditorBrowsable(EditorBrowsableState.Never)]
        internal virtual bool ShouldSerializeBackColor() { 
            Color backColor = Properties.GetColor(PropBackColor);
            return !backColor.IsEmpty; 
        } 

        ///  
        /// 
        ///     Returns true if the cursor should be persisted in code gen.
        /// 
        [EditorBrowsable(EditorBrowsableState.Never)] 
        internal virtual bool ShouldSerializeCursor() {
            bool found; 
            object cursor = Properties.GetObject(PropCursor, out found); 
            return (found && cursor != null);
        } 

        /// 
        ///     Returns true if the enabled property should be persisted in code gen.
        ///  
        [EditorBrowsable(EditorBrowsableState.Never)]
        private bool ShouldSerializeEnabled() { 
            return (!GetState(STATE_ENABLED)); 
        }
 
        /// 
        /// 
        ///     Returns true if the foreColor should be persisted in code gen.
        ///  
        [EditorBrowsable(EditorBrowsableState.Never)]
        internal virtual bool ShouldSerializeForeColor() { 
            Color foreColor = Properties.GetColor(PropForeColor); 
            return !foreColor.IsEmpty;
        } 

        /// 
        /// 
        ///     Returns true if the font should be persisted in code gen. 
        /// 
        [EditorBrowsable(EditorBrowsableState.Never)] 
        internal virtual bool ShouldSerializeFont() { 
            bool found;
            object font = Properties.GetObject(PropFont, out found); 
            return (found && font != null);
        }

        ///  
        /// 
        ///     Returns true if the RightToLeft should be persisted in code gen. 
        ///  
        [EditorBrowsable(EditorBrowsableState.Never)]
        internal virtual bool ShouldSerializeRightToLeft() { 
            bool found;
            int rtl = Properties.GetInteger(PropRightToLeft, out found);
            return (found && rtl != (int)RightToLeft.Inherit);
        } 

        ///  
        ///     Returns true if the visible property should be persisted in code gen. 
        /// 
        [EditorBrowsable(EditorBrowsableState.Never)] 
        private bool ShouldSerializeVisible() {
            return (!GetState(STATE_VISIBLE));
        }
 
        // Helper function - translates text alignment for Rtl controls
        // Read TextAlign as Left == Near, Right == Far 
        ///  
        /// 
        ///    [To be supplied.] 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected HorizontalAlignment RtlTranslateAlignment(HorizontalAlignment align) {
            return RtlTranslateHorizontal(align); 
        }
 
        ///  
        /// 
        ///    [To be supplied.] 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected LeftRightAlignment RtlTranslateAlignment(LeftRightAlignment align) {
            return RtlTranslateLeftRight(align); 
        }
 
        ///  
        /// 
        ///    [To be supplied.] 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected ContentAlignment RtlTranslateAlignment(ContentAlignment align) {
            return RtlTranslateContent(align); 
        }
 
        ///  
        /// 
        ///    [To be supplied.] 
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected HorizontalAlignment RtlTranslateHorizontal(HorizontalAlignment align) {
 
            if (RightToLeft.Yes == RightToLeft) {
                if (HorizontalAlignment.Left == align) { 
                    return HorizontalAlignment.Right; 
                }
                else if (HorizontalAlignment.Right == align) { 
                    return HorizontalAlignment.Left;
                }
            }
 
            return align;
        } 
 
        /// 
        ///  
        ///    [To be supplied.]
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected LeftRightAlignment RtlTranslateLeftRight(LeftRightAlignment align) { 

            if (RightToLeft.Yes == RightToLeft) { 
                if (LeftRightAlignment.Left == align) { 
                    return LeftRightAlignment.Right;
                } 
                else if (LeftRightAlignment.Right == align) {
                    return LeftRightAlignment.Left;
                }
            } 

            return align; 
        } 

        ///  
        /// 
        ///    [To be supplied.]
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected internal ContentAlignment RtlTranslateContent(ContentAlignment align) {
            if (RightToLeft.Yes == RightToLeft) { 
 
                if ((align & WindowsFormsUtils.AnyTopAlign) != 0) {
                    switch (align) { 
                        case ContentAlignment.TopLeft:
                            return ContentAlignment.TopRight;
                        case ContentAlignment.TopRight:
                            return ContentAlignment.TopLeft; 
                    }
                } 
                if ((align & WindowsFormsUtils.AnyMiddleAlign) != 0 ) { 
                    switch (align) {
                        case ContentAlignment.MiddleLeft: 
                            return ContentAlignment.MiddleRight;
                        case ContentAlignment.MiddleRight:
                            return ContentAlignment.MiddleLeft;
                    } 
                }
 
                if ((align & WindowsFormsUtils.AnyBottomAlign) != 0 ) { 
                    switch (align) {
                        case ContentAlignment.BottomLeft: 
                            return ContentAlignment.BottomRight;
                        case ContentAlignment.BottomRight:
                            return ContentAlignment.BottomLeft;
                    } 
                }
            } 
            return align; 
        }
 
        private void SetWindowFont(){
            SendMessage(NativeMethods.WM_SETFONT, FontHandle, 0 /*redraw = false*/);
        }
 
        private void SetWindowStyle(int flag, bool value) {
            int styleFlags = unchecked((int)((long)UnsafeNativeMethods.GetWindowLong(new HandleRef(this, Handle), NativeMethods.GWL_STYLE))); 
            UnsafeNativeMethods.SetWindowLong(new HandleRef(this, Handle), NativeMethods.GWL_STYLE, new HandleRef(null, (IntPtr)(value? styleFlags | flag: styleFlags & ~flag))); 
        }
 

        /// 
        /// 
        ///     Makes the control display by setting the visible property to true 
        /// 
        public void Show() { 
            Visible = true; 
        }
 
        [EditorBrowsable(EditorBrowsableState.Never)]
        internal bool ShouldSerializeMargin() {
            return !Margin.Equals(DefaultMargin);
        } 

        [EditorBrowsable(EditorBrowsableState.Never)] 
        internal virtual bool ShouldSerializeMaximumSize() { 
            return MaximumSize != DefaultMaximumSize;
        } 

        [EditorBrowsable(EditorBrowsableState.Never)]
        internal virtual bool ShouldSerializeMinimumSize() {
            return MinimumSize != DefaultMinimumSize; 
        }
 
        [EditorBrowsable(EditorBrowsableState.Never)] 
        internal bool ShouldSerializePadding() {
            return !Padding.Equals(DefaultPadding); 
        }

        /// 
        ///  
        /// Determines if the  property needs to be persisted.
        ///  
        [EditorBrowsable(EditorBrowsableState.Never)] 
        internal virtual bool ShouldSerializeSize() {
            // VSWhidbey 379287: In Whidbey the ControlDesigner class will always serialize size as it replaces the Size 
            // property descriptor with its own.  This is here for compat.
            Size s = DefaultSize;
            return width != s.Width || height != s.Height;
        } 

        ///  
        ///  
        /// Determines if the  property needs to be persisted.
        ///  
        [EditorBrowsable(EditorBrowsableState.Never)]
        internal virtual bool ShouldSerializeText() {
            return Text.Length != 0;
        } 

        ///  
        ///  
        ///     Suspends the layout logic for the control.
        ///  
        public void SuspendLayout() {


            layoutSuspendCount++; 
            if (layoutSuspendCount == 1) {
                OnLayoutSuspended(); 
            } 

#if DEBUG 
            Debug.Assert(layoutSuspendCount > 0, "SuspendLayout: layoutSuspendCount overflowed.");
            if (CompModSwitches.LayoutSuspendResume.TraceInfo) {
                Debug.WriteLine(GetType().Name + "::SuspendLayout( newCount = " + layoutSuspendCount + ")");
            } 
#endif
        } 
 
        /// 
        ///     Stops listening for the mouse leave event. 
        /// 
        /// 
        private void UnhookMouseEvent() {
            SetState(STATE_TRACKINGMOUSEEVENT, false); 
        }
 
        ///  
        /// 
        ///     Forces the control to paint any currently invalid areas. 
        /// 
        public void Update() {
            SafeNativeMethods.UpdateWindow(new HandleRef(window, InternalHandle));
        } 

        ///  
        ///  
        ///     Updates the bounds of the control based on the handle the control is
        ///     bound to. 
        /// 
        // Internal for ScrollableControl
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected internal void UpdateBounds() { 
            NativeMethods.RECT rect = new NativeMethods.RECT();
            UnsafeNativeMethods.GetClientRect(new HandleRef(window, InternalHandle), ref rect); 
            int clientWidth = rect.right; 
            int clientHeight = rect.bottom;
            UnsafeNativeMethods.GetWindowRect(new HandleRef(window, InternalHandle), ref rect); 
            if (!GetTopLevel()) {
                UnsafeNativeMethods.MapWindowPoints(NativeMethods.NullHandleRef, new HandleRef(null, UnsafeNativeMethods.GetParent(new HandleRef(window, InternalHandle))), ref rect, 2);
            }
 
            UpdateBounds(rect.left, rect.top, rect.right - rect.left,
                         rect.bottom - rect.top, clientWidth, clientHeight); 
        } 

        ///  
        /// 
        ///     Updates the bounds of the control based on the bounds passed in.
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected void UpdateBounds(int x, int y, int width, int height) {
            Debug.Assert(!IsHandleCreated, "Don't call this method when handle is created!!"); 
 
            // reverse-engineer the AdjustWindowRectEx call to figure out
            // the appropriate clientWidth and clientHeight 
            NativeMethods.RECT rect = new NativeMethods.RECT();
            rect.left = rect.right = rect.top = rect.bottom = 0;

            CreateParams cp = CreateParams; 

            SafeNativeMethods.AdjustWindowRectEx(ref rect, cp.Style, false, cp.ExStyle); 
            int clientWidth = width - (rect.right - rect.left); 
            int clientHeight = height - (rect.bottom - rect.top);
            UpdateBounds(x, y, width, height, clientWidth, clientHeight); 
        }

        /// 
        ///  
        ///     Updates the bounds of the control based on the bounds passed in.
        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)] 
        protected void UpdateBounds(int x, int y, int width, int height, int clientWidth, int clientHeight) {
#if DEBUG 
            if (CompModSwitches.SetBounds.TraceVerbose){
               Debug.WriteLine(String.Format(CultureInfo.CurrentCulture, "{0}::UpdateBounds(", Name));
               Debug.Indent();
               Debug.WriteLine(String.Format( 
                    CultureInfo.CurrentCulture, "oldBounds={{x={0} y={1} width={2} height={3} clientWidth={4} clientHeight={5}}}",
                    x, y, width, height, clientWidth, clientHeight)); 
            } 
#endif // DEBUG
 

            bool newLocation = this.x != x || this.y != y;
            bool newSize = this.Width != width || this.Height != height ||
                           this.clientWidth != clientWidth || this.clientHeight != clientHeight; 

            this.x = x; 
            this.y = y; 
            this.width = width;
            this.height = height; 
            this.clientWidth = clientWidth;
            this.clientHeight = clientHeight;

            if (newLocation) { 
#if DEBUG
                Rectangle originalBounds = this.Bounds; 
#endif 
                OnLocationChanged(EventArgs.Empty);
#if DEBUG 
                if (this.Bounds != originalBounds && CompModSwitches.SetBounds.TraceWarning) {
                    Debug.WriteLine(String.Format(CultureInfo.CurrentCulture, "WARNING: Bounds changed during OnLocationChanged()\r\nbefore={0} after={1}", originalBounds, this.Bounds));
                }
#endif 
            }
            if (newSize) { 
#if DEBUG 
                Rectangle originalBounds = this.Bounds;
#endif 
                OnSizeChanged(EventArgs.Empty);
                OnClientSizeChanged(EventArgs.Empty);

                // Clear PreferredSize cache for this control 
                CommonProperties.xClearPreferredSizeCache(this);
                LayoutTransaction.DoLayout(ParentInternal, this, PropertyNames.Bounds); 
 
#if DEBUG
                if (this.Bounds != originalBounds && CompModSwitches.SetBounds.TraceWarning) { 
                    Debug.WriteLine(String.Format(CultureInfo.CurrentCulture, "WARNING: Bounds changed during OnSizeChanged()\r\nbefore={0} after={1}", originalBounds, this.Bounds));
                }
#endif
            } 

 
#if DEBUG 
            if (CompModSwitches.SetBounds.TraceVerbose) {
                Debug.WriteLine(String.Format(CultureInfo.CurrentCulture, "newBounds={{x={0} y={1} width={2} height={3} clientWidth={4} clientHeight={5}}}",x, y, width, height, clientWidth, clientHeight)); 
                Debug.Unindent();
            }
#endif
        } 

        ///  
        ///     Updates the binding manager bindings when the binding proeprty changes. 
        ///     We have the code here, rather than in PropertyChagned, so we don't pull
        ///     in the data assembly if it's not used. 
        /// 
        private void UpdateBindings() {
            for (int i = 0; i < DataBindings.Count; i++) {
                BindingContext.UpdateBinding(BindingContext, DataBindings[i]); 
            }
        } 
 
        /// 
        ///     Updates the child control's position in the control array to correctly 
        ///     reflect it's index.
        /// 
        private void UpdateChildControlIndex(Control ctl) {
            int newIndex = 0; 
            int curIndex = this.Controls.GetChildIndex(ctl);
            IntPtr hWnd = ctl.InternalHandle; 
            while ((hWnd = UnsafeNativeMethods.GetWindow(new HandleRef(null, hWnd), NativeMethods.GW_HWNDPREV)) != IntPtr.Zero) { 
                Control c = FromHandleInternal(hWnd);
                if (c != null) { 
                    newIndex = this.Controls.GetChildIndex(c, false) + 1;
                    break;
                }
            } 
            if (newIndex > curIndex) {
                newIndex--; 
            } 
            if (newIndex != curIndex)
            { 
                this.Controls.SetChildIndex(ctl, newIndex);
            }
        }
 

        // whenever we create our handle, we need to get ahold of the HWND of our parent, 
        // and track if that thing is destroyed, because any messages sent to our parent (e.g. WM_NOTIFY, WM_DRAWITEM, etc) 
        // will continue to be sent to that window even after we do a SetParent call until the handle is recreated.
        // So here we keep track of that, and if that window ever gets destroyed, we'll recreate our handle. 
        //
        //
        // Scenario is when you've got a control in one parent, you move it to another, then destroy the first parent.  It'll stop
        // getting any reflected messages because Windows will send them to the original parent. 
        //
        private void UpdateReflectParent(bool findNewParent) { 
            if (!Disposing && findNewParent && IsHandleCreated) { 
                IntPtr parentHandle = UnsafeNativeMethods.GetParent(new HandleRef(this, Handle));
                if (parentHandle != IntPtr.Zero) { 
                    ReflectParent = Control.FromHandleInternal(parentHandle);
                    return;
                }
            } 
            ReflectParent = null;
        } 
 
        /// 
        ///  
        ///     Updates this control in it's parent's zorder.
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected void UpdateZOrder() { 
            if (parent != null) {
                parent.UpdateChildZOrder(this); 
            } 
        }
 
        /// 
        ///     Syncs the ZOrder of child control to the index we want it to be.
        /// 
        private void UpdateChildZOrder(Control ctl) { 
            if (!IsHandleCreated || !ctl.IsHandleCreated || ctl.parent != this) return;
            IntPtr prevHandle = (IntPtr)NativeMethods.HWND_TOP; 
            for (int i = this.Controls.GetChildIndex(ctl); --i >= 0;) { 
                Control c = Controls[i];
                if (c.IsHandleCreated && c.parent == this) { 
                    prevHandle = c.Handle;
                    break;
                }
            } 
            if (UnsafeNativeMethods.GetWindow(new HandleRef(ctl.window, ctl.Handle), NativeMethods.GW_HWNDPREV) != prevHandle) {
                state |= STATE_NOZORDER; 
                try { 
                    SafeNativeMethods.SetWindowPos(new HandleRef(ctl.window, ctl.Handle), new HandleRef(null, prevHandle), 0, 0, 0, 0,
                                                   NativeMethods.SWP_NOMOVE | NativeMethods.SWP_NOSIZE); 
                }
                finally {
                    state &= ~STATE_NOZORDER;
                } 
            }
        } 
 
        /// 
        ///     Updates the rootReference in the bound window. 
        ///     (Used to prevent visible top-level controls from being garbage collected)
        /// 
        private void UpdateRoot() {
            window.LockReference(GetTopLevel() && Visible); 
        }
 
        ///  
        /// 
        ///     Forces styles to be reapplied to the handle. This function will call 
        ///     CreateParams to get the styles to apply.
        /// 
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        protected void UpdateStyles() { 
            UpdateStylesCore();
 
            OnStyleChanged(EventArgs.Empty); 
        }
 
        internal virtual void UpdateStylesCore() {
            if (IsHandleCreated) {
                CreateParams cp = CreateParams;
                int winStyle = WindowStyle; 
                int exStyle = WindowExStyle;
 
                // resolve the Form's lazy visibility. 
                if ((state & STATE_VISIBLE) != 0){
                    cp.Style |= NativeMethods.WS_VISIBLE; 
                }
                if (winStyle != cp.Style) {
                    WindowStyle = cp.Style;
                } 
                if (exStyle != cp.ExStyle) {
                    WindowExStyle = cp.ExStyle; 
                    SetState(STATE_MIRRORED, (cp.ExStyle & NativeMethods.WS_EX_LAYOUTRTL) != 0); 
                }
 
                SafeNativeMethods.SetWindowPos(
                                              new HandleRef(this, Handle), NativeMethods.NullHandleRef, 0, 0, 0, 0,
                                              NativeMethods.SWP_DRAWFRAME | NativeMethods.SWP_NOACTIVATE | NativeMethods.SWP_NOMOVE
                                              | NativeMethods.SWP_NOSIZE | NativeMethods.SWP_NOZORDER); 

                Invalidate(true); 
            } 
        }
 
        private void UserPreferenceChanged(object sender, UserPreferenceChangedEventArgs pref) {
            if (pref.Category == UserPreferenceCategory.Color) {
                defaultFont = null;
                OnSystemColorsChanged(EventArgs.Empty); 
            }
        } 
 
        //
        // Give a chance for derived controls to do what they want, just before we resize. 
        internal virtual void OnBoundsUpdate(int x, int y, int width, int height)
        {
        }
 
        // These Window* methods allow us to keep access to the "window"
        // property private, which is important for restricting access to the 
        // handle. 
        internal void WindowAssignHandle(IntPtr handle, bool value)
        { 
            window.AssignHandle(handle, value);
        }

        internal void WindowReleaseHandle() 
        {
            window.ReleaseHandle(); 
        } 

        private void WmClose(ref Message m) { 

            // More generic fix for KB article Q125644...
            //
            if (ParentInternal != null) { 
                IntPtr parentHandle = Handle;
                IntPtr lastParentHandle = parentHandle; 
 
                while (parentHandle != IntPtr.Zero) {
                    lastParentHandle = parentHandle; 
                    parentHandle = UnsafeNativeMethods.GetParent(new HandleRef(null, parentHandle));

                    int style = unchecked((int)((long)UnsafeNativeMethods.GetWindowLong(new HandleRef(null, lastParentHandle), NativeMethods.GWL_STYLE)));
 
                    if ((style & NativeMethods.WS_CHILD) == 0) {
                        break; 
                    } 

                } 

                if (lastParentHandle != IntPtr.Zero) {
                    UnsafeNativeMethods.PostMessage(new HandleRef(null, lastParentHandle), NativeMethods.WM_CLOSE, IntPtr.Zero, IntPtr.Zero);
                } 
            }
 
            DefWndProc(ref m); 
        }
 

        /// 
        ///     Handles the WM_CAPTURECHANGED message
        ///  
        /// 
        private void WmCaptureChanged(ref Message m) { 
            OnMouseCaptureChanged(EventArgs.Empty); 
            DefWndProc(ref m);
 
        }
        /// 
        ///     Handles the WM_COMMAND message
        ///  
        /// 
        private void WmCommand(ref Message m) { 
            if (IntPtr.Zero == m.LParam) { 
                if (Command.DispatchID(NativeMethods.Util.LOWORD(m.WParam))) return;
            } 
            else {
                if (ReflectMessageInternal(m.LParam, ref m)) {
                    return;
                } 
            }
            DefWndProc(ref m); 
        } 

        // overridable so nested controls can provide a different source control. 
        internal virtual void WmContextMenu(ref Message m) {
            WmContextMenu(ref m, this);
        }
        ///  
        ///     Handles the WM_CONTEXTMENU message
        ///  
        ///  
        internal void WmContextMenu(ref Message m, Control sourceControl) {
            ContextMenu contextMenu             = Properties.GetObject(PropContextMenu) as ContextMenu; 
            ContextMenuStrip contextMenuStrip   = (contextMenu != null) ? null /*save ourselves a property fetch*/
                                                                        : Properties.GetObject(PropContextMenuStrip) as ContextMenuStrip;

            if (contextMenu != null || contextMenuStrip != null) { 
                int x = NativeMethods.Util.SignedLOWORD(m.LParam);
                int y = NativeMethods.Util.SignedHIWORD(m.LParam); 
                Point client; 
                bool keyboardActivated = false;
                // lparam will be exactly -1 when the user invokes the context menu 
                // with the keyboard.
                //
                if (unchecked((int)(long)m.LParam) == -1) {
                    keyboardActivated = true; 
                    client = new Point(Width/2, Height/2);
                } 
                else { 
                    client = PointToClientInternal(new Point(x, y));
                } 

                //

                // VisualStudio7 # 156, only show the context menu when clicked in the client area 
                if (ClientRectangle.Contains( client )) {
                    if (contextMenu != null) { 
                        contextMenu.Show(sourceControl, client); 
                    }
                    else if (contextMenuStrip != null) { 
                        contextMenuStrip.ShowInternal(sourceControl, client, keyboardActivated);
                    }
                    else {
                      Debug.Fail("contextmenu and contextmenustrip are both null... hmm how did we get here?"); 
                      DefWndProc( ref m );
                    } 
                } 
                else {
                    DefWndProc( ref m ); 
                }
            }
            else {
                DefWndProc(ref m); 
            }
        } 
 
        /// 
        ///     Handles the WM_CTLCOLOR message 
        /// 
        /// 
        private void WmCtlColorControl(ref Message m) {
            // We could simply reflect the message, but it's faster to handle it here if possible. 
            Control control = Control.FromHandleInternal(m.LParam);
            if (control != null) { 
                m.Result = control.InitializeDCForWmCtlColor(m.WParam, m.Msg); 
                if (m.Result != IntPtr.Zero) {
                    return; 
                }
            }

            DefWndProc(ref m); 
        }
 
        private void WmDisplayChange(ref Message m) { 
            BufferedGraphicsManager.Current.Invalidate();
            DefWndProc(ref m); 
        }

        /// 
        ///     WM_DRAWITEM handler 
        /// 
        ///  
        private void WmDrawItem(ref Message m) { 

            // If the wparam is zero, then the message was sent by a menu. 
            // See WM_DRAWITEM in MSDN.
            if (m.WParam == IntPtr.Zero) {
                WmDrawItemMenuItem(ref m);
            } 
            else {
                WmOwnerDraw(ref m); 
            } 
        }
 
        private void WmDrawItemMenuItem(ref Message m) {
            // Obtain the menu item object
            NativeMethods.DRAWITEMSTRUCT dis = (NativeMethods.DRAWITEMSTRUCT)m.GetLParam(typeof(NativeMethods.DRAWITEMSTRUCT));
 
            // A pointer to the correct MenuItem is stored in the draw item
            // information sent with the message. 
            // (See MenuItem.CreateMenuItemInfo) 
            MenuItem menuItem = MenuItem.GetMenuItemFromItemData(dis.itemData);
 
            // Delegate this message to the menu item
            if (menuItem != null) {
                menuItem.WmDrawItem(ref m);
            } 
        }
 
        ///  
        ///     Handles the WM_ERASEBKGND message
        ///  
        /// 
        private void WmEraseBkgnd(ref Message m) {
            if (GetStyle(ControlStyles.UserPaint)) {
                // When possible, it's best to do all painting directly from WM_PAINT. 
                // OptimizedDoubleBuffer is the "same" as turning on AllPaintingInWMPaint
                if (!(GetStyle(ControlStyles.AllPaintingInWmPaint))) { 
                    IntPtr dc = m.WParam; 
                    if (dc == IntPtr.Zero) {    // This happens under extreme stress conditions
                        m.Result = (IntPtr)0; 
                        return;
                    }
                    NativeMethods.RECT rc = new NativeMethods.RECT();
                    UnsafeNativeMethods.GetClientRect(new HandleRef(this, Handle), ref rc); 
                    using (PaintEventArgs pevent = new PaintEventArgs(dc, Rectangle.FromLTRB(rc.left, rc.top, rc.right, rc.bottom))) {
                        PaintWithErrorHandling(pevent, PaintLayerBackground); 
                    } 
                }
                m.Result = (IntPtr)1; 
            }
            else {
                DefWndProc(ref m);
            } 
        }
 
        ///  
        ///     Handles the WM_EXITMENULOOP message. If this control has a context menu, its
        ///     Collapse event is raised. 
        /// 
        /// 
        private void WmExitMenuLoop(ref Message m) {
            bool isContextMenu = (unchecked((int)(long)m.WParam) == 0) ? false : true; 

            if (isContextMenu) { 
                ContextMenu contextMenu = (ContextMenu)Properties.GetObject(PropContextMenu); 
                if (contextMenu != null) {
                    contextMenu.OnCollapse(EventArgs.Empty); 
                }
            }

            DefWndProc(ref m); 
        }
 
        ///  
        ///     Handles the WM_GETCONTROLNAME message. Returns the name of the control.
        ///  
        /// 
        private void WmGetControlName(ref Message m) {
            string name;
 
            if (this.Site != null) {
                name = this.Site.Name; 
            } 
            else {
                name = this.Name; 
            }

            if (name == null)
                name = ""; 

 
            MarshalStringToMessage(name, ref m); 
        }
 
        /// 
        ///     Handles the WM_GETCONTROLTYPE message. Returns the name of the control.
        /// 
        ///  
        private void WmGetControlType(ref Message m) {
            string type = GetType().AssemblyQualifiedName; 
            MarshalStringToMessage(type, ref m); 
        }
 
        /// 
        ///     Handles the WM_GETOBJECT message. Used for accessibility.
        /// 
        ///  
        private void WmGetObject(ref Message m) {
            Debug.WriteLineIf(CompModSwitches.MSAA.TraceInfo, "In WmGetObject, this = " + this.GetType().FullName + ", lParam = " + m.LParam.ToString()); 
 
            InternalAccessibleObject intAccessibleObject = null;
 
            AccessibleObject ctrlAccessibleObject = GetAccessibilityObject(unchecked((int)(long)m.LParam));

            if (ctrlAccessibleObject != null) {
                // SECREVIEW : Asserting here is safe, the interface is used to get the LRESULT from the accessible object 
                //             into the Message.Result.
                // 
                IntSecurity.UnmanagedCode.Assert(); 
                try {
                    intAccessibleObject = new InternalAccessibleObject(ctrlAccessibleObject); 
                }
                finally {
                    CodeAccessPermission.RevertAssert();
                } 
            }
 
            // See "How to Handle WM_GETOBJECT" in MSDN 
            if (intAccessibleObject != null) {
 
                // Get the IAccessible GUID
                //
                Guid IID_IAccessible = new Guid(NativeMethods.uuid_IAccessible);
 
                // Get an Lresult for the accessibility Object for this control
                // 
                IntPtr punkAcc; 
                try {
                    // Sanity check: For security reasons, it is 



                    object tempObject = intAccessibleObject; 
                    IAccessible iAccCheck = tempObject as IAccessible;
                    if (iAccCheck != null) { 
                        throw new InvalidOperationException(SR.GetString(SR.ControlAccessibileObjectInvalid)); 
                    }
 
                    // Check that we have an IAccessibleInternal implementation and return this
                    UnsafeNativeMethods.IAccessibleInternal iacc = (UnsafeNativeMethods.IAccessibleInternal) intAccessibleObject;

                    if (iacc == null) { 
                        // Accessibility is not supported on this control
                        // 
                        Debug.WriteLineIf(CompModSwitches.MSAA.TraceInfo, "AccessibilityObject returned null"); 
                        m.Result = (IntPtr)0;
                    } 
                    else {
                        // Obtain the Lresult
                        //
                        punkAcc = Marshal.GetIUnknownForObject(iacc); 

                        // SECREVIEW : The following assert is required because the interop call below will call into an interface (punkAcc) 
                        //             which demands UnmanagedCode permission.  We make sure we are calling the right into the right interface 
                        //             (see Sanity-Check comment above) and the call is safe since we are just getting the LRESULT from the
                        //             Acc interface.  So this assert is safe. 
                        //
                        IntSecurity.UnmanagedCode.Assert();
                        try {
                            m.Result = UnsafeNativeMethods.LresultFromObject(ref IID_IAccessible, m.WParam, new HandleRef(ctrlAccessibleObject, punkAcc)); 
                            Debug.WriteLineIf(CompModSwitches.MSAA.TraceInfo, "LresultFromObject returned " + m.Result.ToString());
                        } 
                        finally { 
                            CodeAccessPermission.RevertAssert();
                            Marshal.Release(punkAcc); 
                        }
                    }
                }
                catch (Exception e) { 
                    throw new InvalidOperationException(SR.GetString(SR.RichControlLresult), e);
                } 
            } 
            else {  // some accessible object requested that we don't care about, so do default message processing
                DefWndProc(ref m); 
            }
        }

        ///  
        ///     Handles the WM_HELP message
        ///  
        ///  
        private void WmHelp(ref Message m) {
 
            // if there's currently a message box open - grab the help info from it.
            HelpInfo hpi = MessageBox.HelpInfo;
            if (hpi != null) {
                switch (hpi.Option) { 
                    case NativeMethods.HLP_FILE  : Help.ShowHelp (this, hpi.HelpFilePath);
                             break; 
                    case NativeMethods.HLP_KEYWORD : Help.ShowHelp (this, hpi.HelpFilePath, hpi.Keyword); 
                             break;
                    case NativeMethods.HLP_NAVIGATOR : Help.ShowHelp (this, hpi.HelpFilePath, hpi.Navigator); 
                             break;
                    case NativeMethods.HLP_OBJECT : Help.ShowHelp (this, hpi.HelpFilePath, hpi.Navigator, hpi.Param);
                             break;
                } 
            }
 
            // Note: info.hItemHandle is the handle of the window that sent the help message. 
            NativeMethods.HELPINFO info = (NativeMethods.HELPINFO)m.GetLParam(typeof(NativeMethods.HELPINFO));
 
            HelpEventArgs hevent = new HelpEventArgs(new Point(info.MousePos.x, info.MousePos.y));
            OnHelpRequested(hevent);
            if (!hevent.Handled) {
                DefWndProc(ref m); 
            }
 
        } 

        ///  
        ///     Handles the WM_INITMENUPOPUP message
        /// 
        /// 
        private void WmInitMenuPopup(ref Message m) { 
            ContextMenu contextMenu = (ContextMenu)Properties.GetObject(PropContextMenu);
            if (contextMenu != null) { 
 
                if (contextMenu.ProcessInitMenuPopup(m.WParam))
                    return; 
            }
            DefWndProc(ref m);
        }
 
        /// 
        ///     WM_MEASUREITEM handler 
        ///  
        /// 
        private void WmMeasureItem(ref Message m) { 

            // If the wparam is zero, then the message was sent by a menu.
            // See WM_MEASUREITEM in MSDN.
            if (m.WParam == IntPtr.Zero) { 

                // Obtain the menu item object 
                NativeMethods.MEASUREITEMSTRUCT mis = (NativeMethods.MEASUREITEMSTRUCT)m.GetLParam(typeof(NativeMethods.MEASUREITEMSTRUCT)); 

                Debug.Assert(m.LParam != IntPtr.Zero, "m.lparam is null"); 

                // A pointer to the correct MenuItem is stored in the measure item
                // information sent with the message.
                // (See MenuItem.CreateMenuItemInfo) 
                MenuItem menuItem = MenuItem.GetMenuItemFromItemData(mis.itemData);
                Debug.Assert(menuItem != null, "UniqueID is not associated with a menu item"); 
 
                // Delegate this message to the menu item
                if (menuItem != null) { 
                    menuItem.WmMeasureItem(ref m);
                }
            }
            else { 
                WmOwnerDraw(ref m);
            } 
        } 

        ///  
        ///     Handles the WM_MENUCHAR message
        /// 
        /// 
        private void WmMenuChar(ref Message m) { 
            Menu menu = ContextMenu;
            if (menu != null) { 
                menu.WmMenuChar(ref m); 
                if (m.Result != IntPtr.Zero) {
                    // This char is a mnemonic on our menu. 
                    return;
                }
            }
        } 

        ///  
        ///     Handles the WM_MENUSELECT message 
        /// 
        ///  
        private void WmMenuSelect(ref Message m) {
            int item = NativeMethods.Util.LOWORD(m.WParam);
            int flags = NativeMethods.Util.HIWORD(m.WParam);
            IntPtr hmenu = m.LParam; 
            MenuItem mi = null;
 
            if ((flags & NativeMethods.MF_SYSMENU) != 0) { 
                // nothing
            } 
            else if ((flags & NativeMethods.MF_POPUP) == 0) {
                Command cmd = Command.GetCommandFromID(item);
                if (cmd != null) {
                    Object reference = cmd.Target; 
                    if (reference != null && reference is MenuItem.MenuItemData) {
                        mi = ((MenuItem.MenuItemData)reference).baseItem; 
                    } 
                }
            } 
            else {
                mi = GetMenuItemFromHandleId(hmenu, item);
            }
 
            if (mi != null) {
                mi.PerformSelect(); 
            } 

            DefWndProc(ref m); 
        }

        /// 
        ///     Handles the WM_CREATE message 
        /// 
        ///  
        private void WmCreate(ref Message m) { 

            DefWndProc(ref m); 

            if (parent != null) {
                parent.UpdateChildZOrder(this);
            } 
            UpdateBounds();
 
            // Let any interested sites know that we've now created a handle 
            //
            OnHandleCreated(EventArgs.Empty); 

            // this code is important -- it is critical that we stash away
            // the value of the text for controls such as edit, button,
            // label, etc. Without this processing, any time you change a 
            // property that forces handle recreation, you lose your text!
            // See the below code in wmDestroy 
            // 
            if (!GetStyle(ControlStyles.CacheText)) {
                text = null; 
            }
        }

        ///  
        ///     Handles the WM_DESTROY message
        ///  
        ///  
        private void WmDestroy(ref Message m) {
            // Let any interested sites know that we're destroying our handle 
            //

            // Disabling the assert for M2 VSWhidbey 122139
            //Debug.Assert(IsHandleCreated, "Need to have the handle here"); 

            if (!RecreatingHandle && !Disposing && !IsDisposed && GetState(STATE_TRACKINGMOUSEEVENT)) 
            { 
                // VSWhidbey 339087. Raise the MouseLeave event for the control below the mouse
                // when a modal dialog is discarded. 
                OnMouseLeave(EventArgs.Empty);
                UnhookMouseEvent();
            }
 
            OnHandleDestroyed(EventArgs.Empty);
 
            if (!Disposing) { 
                // If we are not recreating the handle, set our created state
                // back to false so we can be rebuilt if we need to be. 
                //
                if (!RecreatingHandle) {
                    SetState(STATE_CREATED, false);
                } 
            }
            else { 
                SetState(STATE_VISIBLE, false); 
            }
 
            DefWndProc(ref m);
        }

        ///  
        ///     Handles the WM_CHAR, WM_KEYDOWN, WM_SYSKEYDOWN, WM_KEYUP, and
        ///     WM_SYSKEYUP messages. 
        ///  
        /// 
        private void WmKeyChar(ref Message m) { 
            if (ProcessKeyMessage(ref m)) return;
            DefWndProc(ref m);
        }
 
        /// 
        ///     Handles the WM_KILLFOCUS message 
        ///  
        /// 
        private void WmKillFocus(ref Message m) { 
            Debug.WriteLineIf(Control.FocusTracing.TraceVerbose, "Control::WmKillFocus - " + this.Name);
            WmImeKillFocus();
            DefWndProc(ref m);
            OnLostFocus(EventArgs.Empty); 
        }
 
        ///  
        ///     Handles the WM_MOUSEDOWN message
        ///  
        /// 
        private void WmMouseDown(ref Message m, MouseButtons button, int clicks) {
            // If this is a "real" mouse event (not just WM_LBUTTONDOWN, etc) then
            // we need to see if something happens during processing of 
            // user code that changed the state of the buttons (i.e. bringing up
            // a dialog) to keep the control in a consistent state... 
            // 
            MouseButtons realState = MouseButtons;
            SetState(STATE_MOUSEPRESSED, true); 

            // If the UserMouse style is set, the control does its own processing
            // of mouse messages
            // 
            if (!GetStyle(ControlStyles.UserMouse)) {
                DefWndProc(ref m); 
            } 
            else {
                // DefWndProc would normally set the focus to this control, but 
                // since we're skipping DefWndProc, we need to do it ourselves.
                if (button == MouseButtons.Left && GetStyle(ControlStyles.Selectable)) {
                    FocusInternal();
                } 
            }
 
            if (realState != MouseButtons) { 
                return;
            } 

            if (!GetState2(STATE2_MAINTAINSOWNCAPTUREMODE)) {
                //CaptureInternal is set usually in MouseDown (ToolStrip main exception)
                CaptureInternal = true; 
            }
 
            if (realState != MouseButtons) { 
                return;
            } 

            // control should be enabled when this method is entered, but may have become
            // disabled during its lifetime (e.g. through a Click or Focus listener)
            if (Enabled) { 
                OnMouseDown(new MouseEventArgs(button, clicks, NativeMethods.Util.SignedLOWORD(m.LParam), NativeMethods.Util.SignedHIWORD(m.LParam), 0));
            } 
        } 

        ///  
        ///     Handles the WM_MOUSEENTER message
        /// 
        /// 
        private void WmMouseEnter(ref Message m) { 
            DefWndProc(ref m);
            OnMouseEnter(EventArgs.Empty); 
        } 

        ///  
        ///     Handles the WM_MOUSELEAVE message
        /// 
        /// 
        private void WmMouseLeave(ref Message m) { 
            DefWndProc(ref m);
            OnMouseLeave(EventArgs.Empty); 
        } 

        ///  
        ///     Handles the "WM_MOUSEHOVER" message... until we get actuall OS support
        ///     for this, it is implemented as a custom message.
        /// 
        ///  
        private void WmMouseHover(ref Message m) {
            DefWndProc(ref m); 
            OnMouseHover(EventArgs.Empty); 
        }
 
        /// 
        ///     Handles the WM_MOUSEMOVE message
        /// 
        ///  
        private void WmMouseMove(ref Message m) {
            // If the UserMouse style is set, the control does its own processing 
            // of mouse messages 
            //
            if (!GetStyle(ControlStyles.UserMouse)) { 
                DefWndProc(ref m);
            }
            OnMouseMove(new MouseEventArgs(MouseButtons, 0, NativeMethods.Util.SignedLOWORD(m.LParam), NativeMethods.Util.SignedHIWORD(m.LParam), 0));
        } 

        ///  
        ///     Handles the WM_MOUSEUP message 
        /// 
        ///  
        private void WmMouseUp(ref Message m, MouseButtons button, int clicks) {
            // Get the mouse location
            //
            try { 
                int x = NativeMethods.Util.SignedLOWORD(m.LParam);
                int y = NativeMethods.Util.SignedHIWORD(m.LParam); 
                Point pt = new Point(x,y); 
                pt = PointToScreen(pt);
 
                // If the UserMouse style is set, the control does its own processing
                // of mouse messages
                //
                if (!GetStyle(ControlStyles.UserMouse)) { 
                    DefWndProc(ref m);
                } 
                else { 
                    // DefWndProc would normally trigger a context menu here
                    // (for a right button click), but since we're skipping DefWndProc 
                    // we have to do it ourselves.
                    if (button == MouseButtons.Right) {
                        SendMessage(NativeMethods.WM_CONTEXTMENU, this.Handle, NativeMethods.Util.MAKELPARAM(pt.X, pt.Y));
                    } 
                }
 
                bool fireClick = false; 

                if ((controlStyle & ControlStyles.StandardClick) == ControlStyles.StandardClick) { 
                    if (GetState(STATE_MOUSEPRESSED) && !IsDisposed && UnsafeNativeMethods.WindowFromPoint(pt.X, pt.Y) == Handle) {
                    fireClick = true;
                    }
                } 

                if (fireClick && !ValidationCancelled) { 
                    if (!GetState(STATE_DOUBLECLICKFIRED)) { 
                        //OnClick(EventArgs.Empty);
                        //In Whidbey .. if the click in by MOUSE then pass the MouseEventArgs... 
                        OnClick(new MouseEventArgs(button, clicks, NativeMethods.Util.SignedLOWORD(m.LParam), NativeMethods.Util.SignedHIWORD(m.LParam), 0));
                        OnMouseClick(new MouseEventArgs(button, clicks, NativeMethods.Util.SignedLOWORD(m.LParam), NativeMethods.Util.SignedHIWORD(m.LParam), 0));

                    } 

                    else { 
                        //OnDoubleClick(EventArgs.Empty); 
                        OnDoubleClick(new MouseEventArgs(button, 2, NativeMethods.Util.SignedLOWORD(m.LParam), NativeMethods.Util.SignedHIWORD(m.LParam), 0));
                        OnMouseDoubleClick(new MouseEventArgs(button, 2, NativeMethods.Util.SignedLOWORD(m.LParam), NativeMethods.Util.SignedHIWORD(m.LParam), 0)); 
                    }

                }
                //call the MouseUp Finally... 
                OnMouseUp(new MouseEventArgs(button, clicks, NativeMethods.Util.SignedLOWORD(m.LParam), NativeMethods.Util.SignedHIWORD(m.LParam), 0));
            } 
            finally { 
                //Always Reset the STATE_DOUBLECLICKFIRED in UP.. Since we get UP - DOWN - DBLCLK - UP sequqnce
                //The Flag is set in L_BUTTONDBLCLK in the controls WndProc() ... 
                //
                SetState(STATE_DOUBLECLICKFIRED, false);
                SetState(STATE_MOUSEPRESSED, false);
                SetState(STATE_VALIDATIONCANCELLED, false); 
                //CaptureInternal is Resetted while exiting the MouseUp
                CaptureInternal = false; 
            } 
        }
 
        /// 
        ///     Handles the WM_MOUSEWHEEL message
        /// 
        ///  
        private void WmMouseWheel(ref Message m) {
            Point p = new Point(NativeMethods.Util.SignedLOWORD(m.LParam), NativeMethods.Util.SignedHIWORD(m.LParam)); 
            p = PointToClient(p); 
            HandledMouseEventArgs e = new HandledMouseEventArgs(MouseButtons.None,
                                                                0, 
                                                                p.X,
                                                                p.Y,
                                                                NativeMethods.Util.SignedHIWORD(m.WParam));
            OnMouseWheel(e); 
            m.Result = (IntPtr) (e.Handled ? 0 : 1);
            if (!e.Handled) 
            { 
                // Forwarding the message to the parent window
                DefWndProc(ref m); 
            }
        }

        ///  
        ///     Handles the WM_MOVE message.  We must do this in
        ///     addition to WM_WINDOWPOSCHANGED because windows may 
        ///     send WM_MOVE directly. 
        /// 
        ///  
        private void WmMove(ref Message m) {
            DefWndProc(ref m);
            UpdateBounds();
        } 

        ///  
        ///     Handles the WM_NOTIFY message 
        /// 
        ///  
        private unsafe void WmNotify(ref Message m) {
            NativeMethods.NMHDR* nmhdr = (NativeMethods.NMHDR*)m.LParam;
            if (!ReflectMessageInternal(nmhdr->hwndFrom,ref m)) {
                if(nmhdr->code == NativeMethods.TTN_SHOW) { 
                    m.Result = UnsafeNativeMethods.SendMessage(new HandleRef(null, nmhdr->hwndFrom), NativeMethods.WM_REFLECT + m.Msg, m.WParam, m.LParam);
                    return; 
                } 
                if(nmhdr->code == NativeMethods.TTN_POP) {
                    UnsafeNativeMethods.SendMessage(new HandleRef(null, nmhdr->hwndFrom), NativeMethods.WM_REFLECT + m.Msg, m.WParam, m.LParam); 
                }

                DefWndProc(ref m);
            } 

        } 
 
        /// 
        ///     Handles the WM_NOTIFYFORMAT message 
        /// 
        /// 
        private void WmNotifyFormat(ref Message m) {
            if (!ReflectMessageInternal(m.WParam, ref m)) { 
                DefWndProc(ref m);
            } 
        } 

        ///  
        ///     Handles the WM_OWNERDRAW message
        /// 
        /// 
        private void WmOwnerDraw(ref Message m) { 
            bool reflectCalled = false;
            if (!ReflectMessageInternal(m.WParam, ref m)) { 
                //Additional Check For Control .... TabControl truncates the Hwnd value... 
                IntPtr handle = window.GetHandleFromID((short)NativeMethods.Util.LOWORD(m.WParam));
                if (handle != IntPtr.Zero) { 
                    Control control = Control.FromHandleInternal(handle);
                    if (control != null) {
                        m.Result = control.SendMessage(NativeMethods.WM_REFLECT + m.Msg, handle, m.LParam);
                        reflectCalled = true; 
                    }
                } 
            } 
            else  {
                reflectCalled = true; 
            }


            if (!reflectCalled) { 
              DefWndProc(ref m);
            } 
        } 

        ///  
        ///     Handles the WM_PAINT messages.  This should only be called
        ///     for userpaint controls.
        /// 
        ///  
        private void WmPaint(ref Message m) {
            bool doubleBuffered = DoubleBuffered || (GetStyle(ControlStyles.AllPaintingInWmPaint) && DoubleBufferingEnabled); 
#if DEBUG 
            if (BufferDisabled.Enabled) {
                doubleBuffered = false; 
            }
#endif
            IntPtr hWnd = IntPtr.Zero;
            IntPtr dc; 
            Rectangle clip;
            NativeMethods.PAINTSTRUCT ps = new NativeMethods.PAINTSTRUCT(); 
            bool needDisposeDC = false; 

            try { 
                if (m.WParam == IntPtr.Zero) {
                    // Cache Handle not only for perf but to avoid object disposed exception in case the window
                    // is destroyed in an event handler (VSW#261657).
                    hWnd = this.Handle; 
                    dc = UnsafeNativeMethods.BeginPaint(new HandleRef(this, hWnd), ref ps);
                    needDisposeDC = true; 
                    clip = new Rectangle(ps.rcPaint_left, ps.rcPaint_top, 
                                         ps.rcPaint_right - ps.rcPaint_left,
                                         ps.rcPaint_bottom - ps.rcPaint_top); 
                }
                else {
                    dc = m.WParam;
                    clip = ClientRectangle; 
                }
 
                // Consider: Why don't check the clip condition when non-doubleBuffered? 
                //           we should probably get rid of the !doubleBuffered condition.
                if (!doubleBuffered || (clip.Width > 0 && clip.Height > 0)) { 
                    IntPtr oldPal = IntPtr.Zero;
                    BufferedGraphics bufferedGraphics = null;
                    PaintEventArgs pevent = null;
                    GraphicsState state = null; 

                    try { 
                        if (doubleBuffered || m.WParam == IntPtr.Zero) { 
                            oldPal = SetUpPalette(dc, false, false);
                        } 

                        if (doubleBuffered) {
                            try {
                                bufferedGraphics = BufferContext.Allocate(dc, ClientRectangle); 
#if DEBUG
                                if (BufferPinkRect.Enabled) { 
                                        Rectangle band = ClientRectangle; 
                                        using( BufferedGraphics bufferedGraphics2 = BufferContext.Allocate( dc, band ) ) {
                                            bufferedGraphics2.Graphics.FillRectangle( new SolidBrush( Color.Red ), band ); 
                                            bufferedGraphics2.Render();
                                    }
                                    Thread.Sleep(50);
                                } 
#endif
                            } 
                            catch (Exception ex) { 
                                if (ClientUtils.IsCriticalException(ex)) {
                                    throw; 
                                }
#if DEBUG
                                if( BufferPinkRect.Enabled ) {
                                    Debug.WriteLine("Could not create buffered graphics, will paint in the surface directly" ); 
                                }
#endif 
                                doubleBuffered = false; // paint directly on the window DC. 
                            }
                        } 

                        if (bufferedGraphics != null) {
                            bufferedGraphics.Graphics.SetClip(clip);
                            pevent = new PaintEventArgs(bufferedGraphics.Graphics, clip); 
                            state = pevent.Graphics.Save();
                        } 
                        else { 
                            pevent = new PaintEventArgs(dc, clip);
                        } 

                        using (pevent) {
                            if ((m.WParam == IntPtr.Zero) && GetStyle(ControlStyles.AllPaintingInWmPaint) || doubleBuffered) {
                                PaintWithErrorHandling(pevent, PaintLayerBackground); 
                                // Consider: This condition could be elimiated,
                                //           do we have to save/restore the state of the buffered graphics? 
                                if (state != null) { 
                                    pevent.Graphics.Restore(state);
                                } 
                                else {
                                    pevent.ResetGraphics();
                                }
                            } 

                            PaintWithErrorHandling(pevent, PaintLayerForeground); 
 
                            if (bufferedGraphics != null) {
                                bufferedGraphics.Render(); 
                            }
                        }
                    }
                    finally { 
                        if (bufferedGraphics != null) {
                            bufferedGraphics.Dispose(); 
                        } 

                        if (oldPal != IntPtr.Zero) { 
                            SafeNativeMethods.SelectPalette(new HandleRef(null, dc), new HandleRef(null, oldPal), 0);
                        }
                    }
                } 
            }
            finally { 
                if (needDisposeDC) { 
                    UnsafeNativeMethods.EndPaint(new HandleRef(this, hWnd), ref ps);
                } 
            }
        }

        ///  
        ///     Handles the WM_PRINTCLIENT messages.
        ///  
        ///  
        private void WmPrintClient(ref Message m) {
            using (PaintEventArgs e = new PrintPaintEventArgs(m, m.WParam, ClientRectangle)) { 
                OnPrint(e);
            }
        }
 
        private void WmQueryNewPalette(ref Message m) {
            Debug.WriteLineIf(Control.PaletteTracing.TraceVerbose, Handle + ": WM_QUERYNEWPALETTE"); 
            IntPtr dc = UnsafeNativeMethods.GetDC(new HandleRef(this, Handle)); 
            try {
                SetUpPalette(dc, true /*force*/, true/*realize*/); 
            }
            finally {
                // Let WmPaletteChanged do any necessary invalidation
                UnsafeNativeMethods.ReleaseDC(new HandleRef(this, Handle), new HandleRef(null, dc)); 
            }
            Invalidate(true); 
            m.Result = (IntPtr)1; 
            DefWndProc(ref m);
        } 


        /// 
        ///     Handles the WM_SETCURSOR message 
        /// 
        ///  
        private void WmSetCursor(ref Message m) { 

            // Accessing through the Handle property has side effects that break this 
            // logic. You must use InternalHandle.
            //
            if (m.WParam == InternalHandle && NativeMethods.Util.LOWORD(m.LParam) == NativeMethods.HTCLIENT) {
                Cursor.CurrentInternal = Cursor; 
            }
            else { 
                DefWndProc(ref m); 
            }
 
        }

        /// 
        ///     Handles the WM_WINDOWPOSCHANGING message 
        /// 
        ///  
        private unsafe void WmWindowPosChanging(ref Message m) { 

            // We let this fall through to defwndproc unless we are being surfaced as 
            // an ActiveX control.  In that case, we must let the ActiveX side of things
            // manipulate our bounds here.
            //
            if (IsActiveX) { 
                NativeMethods.WINDOWPOS* wp = (NativeMethods.WINDOWPOS *)m.LParam;
                // Only call UpdateBounds if the new bounds are different. 
                // 
                bool different = false;
 
                if ((wp->flags & NativeMethods.SWP_NOMOVE) == 0 && (wp->x != Left || wp->y != Top)) {
                    different = true;
                }
                if ((wp->flags & NativeMethods.SWP_NOSIZE) == 0 && (wp->cx != Width || wp->cy != Height)) { 
                    different = true;
                } 
 
                if (different) {
                    ActiveXUpdateBounds(ref wp->x, ref wp->y, ref wp->cx, ref wp->cy, wp->flags); 
                }
            }

            DefWndProc(ref m); 
        }
 
 
        /// 
        ///     Handles the WM_PARENTNOTIFY message 
        /// 
        /// 
        private void WmParentNotify(ref Message m) {
            int msg = NativeMethods.Util.LOWORD(m.WParam); 
            IntPtr hWnd = IntPtr.Zero;
            switch (msg) { 
                case NativeMethods.WM_CREATE: 
                    hWnd = m.LParam;
                    break; 
                case NativeMethods.WM_DESTROY:
                    break;
                default:
                    hWnd = UnsafeNativeMethods.GetDlgItem(new HandleRef(this, Handle), NativeMethods.Util.HIWORD(m.WParam)); 
                    break;
            } 
            if (hWnd == IntPtr.Zero || !ReflectMessageInternal(hWnd, ref m)) { 
                DefWndProc(ref m);
            } 
        }

        /// 
        ///     Handles the WM_SETFOCUS message 
        /// 
        ///  
        private void WmSetFocus(ref Message m) { 
            Debug.WriteLineIf(Control.FocusTracing.TraceVerbose, "Control::WmSetFocus - " + this.Name);
            WmImeSetFocus(); 

            if (!HostedInWin32DialogManager) {
                IContainerControl c = GetContainerControlInternal();
                if (c != null) { 
                    bool activateSucceed;
 
                    ContainerControl knowncontainer = c as ContainerControl; 
                    if (knowncontainer != null) {
                        activateSucceed = knowncontainer.ActivateControlInternal(this); 
                    }
                    else {
                        // Reviewed : Taking focus and activating a control in response
                        //          : to a user gesture (WM_SETFOCUS) is OK. 
                        //
                        IntSecurity.ModifyFocus.Assert(); 
                        try { 
                            activateSucceed = c.ActivateControl(this);
                        } 
                        finally {
                            CodeAccessPermission.RevertAssert();
                        }
                    } 

                    if (!activateSucceed) { 
                        return; 
                    }
                } 
            }

            DefWndProc(ref m);
            OnGotFocus(EventArgs.Empty); 
        }
 
        ///  
        ///     Handles the WM_SHOWWINDOW message
        ///  
        /// 
        private void WmShowWindow(ref Message m) {
            // We get this message for each control, even if their parent is not visible.
 
            DefWndProc(ref m);
 
            if ((state & STATE_RECREATE) == 0) { 

                bool visible = m.WParam != IntPtr.Zero; 
                bool oldVisibleProperty = Visible;

                if (visible) {
                    bool oldVisibleBit = GetState(STATE_VISIBLE); 
                    SetState(STATE_VISIBLE, true);
                    bool executedOk = false; 
                    try { 
                        CreateControl();
                        executedOk = true; 
                    }

                    finally {
                        if (!executedOk) { 
                            // We do it this way instead of a try/catch because catching and rethrowing
                            // an exception loses call stack information 
                            SetState(STATE_VISIBLE, oldVisibleBit); 
                        }
                    } 
                }
                else { // not visible
                    // If Windows tells us it's visible, that's pretty unambiguous.
                    // But if it tells us it's not visible, there's more than one explanation -- 
                    // maybe the container control became invisible.  So we look at the parent
                    // and take a guess at the reason. 
 
                    // We do not want to update state if we are on the parking window.
                    bool parentVisible = GetTopLevel(); 
                    if (ParentInternal != null) {
                        parentVisible = ParentInternal.Visible;
                    }
 
                    if (parentVisible) {
                        SetState(STATE_VISIBLE, false); 
                    } 
                }
 
                if (!GetState(STATE_PARENTRECREATING) && (oldVisibleProperty != visible)) {
                    OnVisibleChanged(EventArgs.Empty);
                }
            } 
        }
 
        ///  
        ///     Handles the WM_UPDATEUISTATE message
        ///  
        /// 
        private void WmUpdateUIState(ref Message m) {

            // See "How this all works" in ShowKeyboardCues 

            bool keyboard = false; 
            bool focus = false; 

            // check the cached values in uiCuesState to see if we've ever set in the UI state 
            bool keyboardInitialized = (uiCuesState & UISTATE_KEYBOARD_CUES_MASK) != 0;
            bool focusInitialized = (uiCuesState & UISTATE_FOCUS_CUES_MASK) != 0;

            if (keyboardInitialized) { 
                keyboard = ShowKeyboardCues;
            } 
 
            if (focusInitialized) {
                focus = ShowFocusCues; 
            }

            DefWndProc(ref m);
 
            int cmd = NativeMethods.Util.LOWORD(m.WParam);
 
            // if we're initializing, dont bother updating the uiCuesState/Firing the event. 

            if (cmd == NativeMethods.UIS_INITIALIZE) { 
                return;
            }

            // Set in the cached value for uiCuesState... 

            // Windows stores the opposite of what you would think, it has bit 
            // flags for the "Hidden" state, the presence of this flag means its 
            // hidden, the absence thereof means it's shown.
            // 
            // When we're called here with a UIS_CLEAR and the hidden state is set
            // that means we want to show the accelerator.
            UICues UIcues = UICues.None;
            if ((NativeMethods.Util.HIWORD(m.WParam) & NativeMethods.UISF_HIDEACCEL) != 0) { 

                // yes, clear means show.  nice api, guys. 
                // 
                bool showKeyboard = (cmd == NativeMethods.UIS_CLEAR);
 
                if (showKeyboard != keyboard || !keyboardInitialized ) {

                    UIcues |= UICues.ChangeKeyboard;
 
                    // clear the old state.
                    // 
                    uiCuesState &= ~UISTATE_KEYBOARD_CUES_MASK; 
                    uiCuesState |= (showKeyboard ? UISTATE_KEYBOARD_CUES_SHOW : UISTATE_KEYBOARD_CUES_HIDDEN) ;
                } 

                if (showKeyboard) {
                    UIcues |= UICues.ShowKeyboard;
                } 
            }
 
            // Same deal for the Focus cues as the keyboard cues. 
            if ((NativeMethods.Util.HIWORD(m.WParam) & NativeMethods.UISF_HIDEFOCUS) != 0) {
 
                // yes, clear means show.  nice api, guys.
                //
                bool showFocus = (cmd == NativeMethods.UIS_CLEAR);
 
                if (showFocus != focus || !focusInitialized) {
                    UIcues |= UICues.ChangeFocus; 
 
                    // clear the old state.
                    // 
                    uiCuesState &= ~UISTATE_FOCUS_CUES_MASK;
                    uiCuesState |= (showFocus ? UISTATE_FOCUS_CUES_SHOW : UISTATE_FOCUS_CUES_HIDDEN) ;
                }
 
                if (showFocus) {
                    UIcues |= UICues.ShowFocus; 
                } 
            }
 

            // fire the UI cues state changed event.
            if ((UIcues & UICues.Changed) != 0) {
                OnChangeUICues(new UICuesEventArgs(UIcues)); 
                Invalidate(true);
            } 
        } 

        ///  
        ///     Handles the WM_WINDOWPOSCHANGED message
        /// 
        /// 
        private unsafe void WmWindowPosChanged(ref Message m) { 
            DefWndProc(ref m);
            // Update new size / position 
            UpdateBounds(); 
            if (parent != null && UnsafeNativeMethods.GetParent(new HandleRef(window, InternalHandle)) == parent.InternalHandle &&
                (state & STATE_NOZORDER) == 0) { 

                NativeMethods.WINDOWPOS* wp = (NativeMethods.WINDOWPOS *)m.LParam;
                if ((wp->flags & NativeMethods.SWP_NOZORDER) == 0) {
                    parent.UpdateChildControlIndex(this); 
                }
            } 
        } 

        ///  
        /// 
        ///     Base wndProc. All messages are sent to wndProc after getting filtered
        ///     through the preProcessMessage function. Inheriting controls should
        ///     call base.wndProc for any messages that they don't handle. 
        /// 
        [ 
            SecurityPermission(SecurityAction.InheritanceDemand, Flags=SecurityPermissionFlag.UnmanagedCode), 
            SecurityPermission(SecurityAction.LinkDemand, Flags=SecurityPermissionFlag.UnmanagedCode)
        ] 
        protected virtual void WndProc(ref Message m) {
            //
            //
 

 
 
            /*
            if( GetState(STATE_DISPOSED)) 
            {
                Debug.Fail("Attempting to process a windows message in a disposed control.  This may be OK if the app domain is being unloaded.");
                DefWndProc(ref m);
                return; 
            }
            */ 
 
            // inlined code from GetStyle(...) to ensure no perf hit
            // for a method call... 
            //
            if ((controlStyle & ControlStyles.EnableNotifyMessage) == ControlStyles.EnableNotifyMessage) {
                // pass message *by value* to avoid the possibility
                // of the OnNotifyMessage modifying the message. 
                //
                OnNotifyMessage(m); 
            } 

            /* 
            * If you add any new messages below (or change the message handling code for any messages)
            * please make sure that you also modify AxHost.wndProc to do the right thing and intercept
            * messages which the Ocx would own before passing them onto Control.wndProc.
            */ 
            switch (m.Msg) {
                case NativeMethods.WM_CAPTURECHANGED: 
                     WmCaptureChanged(ref m); 
                     break;
 
                case NativeMethods.WM_GETOBJECT:
                    WmGetObject(ref m);
                    break;
 
                case NativeMethods.WM_COMMAND:
                    WmCommand(ref m); 
                    break; 
                case NativeMethods.WM_CLOSE:
                    WmClose(ref m); 
                    break;
                case NativeMethods.WM_CONTEXTMENU:
                    WmContextMenu(ref m);
                    break; 
                case NativeMethods.WM_DISPLAYCHANGE:
                    WmDisplayChange(ref m); 
                    break; 
                case NativeMethods.WM_DRAWITEM:
                    WmDrawItem(ref m); 
                    break;
                case NativeMethods.WM_ERASEBKGND:
                    WmEraseBkgnd(ref m);
                    break; 

                case NativeMethods.WM_EXITMENULOOP: 
                    WmExitMenuLoop(ref m); 
                    break;
 
                case NativeMethods.WM_HELP:
                    WmHelp(ref m);
                    break;
 
                case NativeMethods.WM_PAINT:
                    if (GetStyle(ControlStyles.UserPaint)) { 
                        WmPaint(ref m); 
                    }
                    else { 
                        DefWndProc(ref m);
                    }
                    break;
 
                case NativeMethods.WM_PRINTCLIENT:
                    if (GetStyle(ControlStyles.UserPaint)) { 
                        WmPrintClient(ref m); 
                    }
                    else { 
                        DefWndProc(ref m);
                    }
                    break;
 
                case NativeMethods.WM_INITMENUPOPUP:
                    WmInitMenuPopup(ref m); 
                    break; 

                case NativeMethods.WM_SYSCOMMAND: 
                    if ((unchecked((int)(long)m.WParam) & 0xFFF0) == NativeMethods.SC_KEYMENU) {
                        Debug.WriteLineIf(ControlKeyboardRouting.TraceVerbose, "Control.WndProc processing " + m.ToString());

                        if (ToolStripManager.ProcessMenuKey(ref m)) { 
                            Debug.WriteLineIf(ControlKeyboardRouting.TraceVerbose, "Control.WndProc ToolStripManager.ProcessMenuKey returned true" + m.ToString());
                            m.Result = IntPtr.Zero; 
                            return; 
                        }
                    } 
                    DefWndProc(ref m);
                break;
                case NativeMethods.WM_INPUTLANGCHANGE:
                    WmInputLangChange(ref m); 
                    break;
 
                case NativeMethods.WM_INPUTLANGCHANGEREQUEST: 
                    WmInputLangChangeRequest(ref m);
                    break; 

                case NativeMethods.WM_MEASUREITEM:
                    WmMeasureItem(ref m);
                    break; 
                case NativeMethods.WM_MENUCHAR:
                    WmMenuChar(ref m); 
                    break; 

                case NativeMethods.WM_MENUSELECT: 
                    WmMenuSelect(ref m);
                    break;

                case NativeMethods.WM_SETCURSOR: 
                    WmSetCursor(ref m);
                    break; 
 
                case NativeMethods.WM_WINDOWPOSCHANGING:
                    WmWindowPosChanging(ref m); 
                    break;

                case NativeMethods.WM_CHAR:
                case NativeMethods.WM_KEYDOWN: 
                case NativeMethods.WM_SYSKEYDOWN:
                case NativeMethods.WM_KEYUP: 
                case NativeMethods.WM_SYSKEYUP: 
                    WmKeyChar(ref m);
                    break; 
                case NativeMethods.WM_CREATE:
                    WmCreate(ref m);
                    break;
                case NativeMethods.WM_DESTROY: 
                    WmDestroy(ref m);
                    break; 
 

                case NativeMethods.WM_CTLCOLOR: 
                case NativeMethods.WM_CTLCOLORBTN:
                case NativeMethods.WM_CTLCOLORDLG:
                case NativeMethods.WM_CTLCOLORMSGBOX:
                case NativeMethods.WM_CTLCOLORSCROLLBAR: 
                case NativeMethods.WM_CTLCOLOREDIT:
                case NativeMethods.WM_CTLCOLORLISTBOX: 
                case NativeMethods.WM_CTLCOLORSTATIC: 

                // VSWhidbey 165168 -- this is for the trinity guys.  The case is if you've got a windows 
                // forms edit or something hosted as an AX control somewhere, there isn't anyone to reflect
                // these back.  If they went ahead and just sent them back, some controls don't like that
                // and end up recursing.  Our code handles it fine because we just pick the HWND out of the LPARAM.
                // 
                case NativeMethods.WM_REFLECT + NativeMethods.WM_CTLCOLOR:
                case NativeMethods.WM_REFLECT + NativeMethods.WM_CTLCOLORBTN: 
                case NativeMethods.WM_REFLECT + NativeMethods.WM_CTLCOLORDLG: 
                case NativeMethods.WM_REFLECT + NativeMethods.WM_CTLCOLORMSGBOX:
                case NativeMethods.WM_REFLECT + NativeMethods.WM_CTLCOLORSCROLLBAR: 
                case NativeMethods.WM_REFLECT + NativeMethods.WM_CTLCOLOREDIT:
                case NativeMethods.WM_REFLECT + NativeMethods.WM_CTLCOLORLISTBOX:
                case NativeMethods.WM_REFLECT + NativeMethods.WM_CTLCOLORSTATIC:
                    WmCtlColorControl(ref m); 
                    break;
                case NativeMethods.WM_HSCROLL: 
                case NativeMethods.WM_VSCROLL: 
                case NativeMethods.WM_DELETEITEM:
                case NativeMethods.WM_VKEYTOITEM: 
                case NativeMethods.WM_CHARTOITEM:
                case NativeMethods.WM_COMPAREITEM:
                    if (!ReflectMessageInternal(m.LParam, ref m)) {
                        DefWndProc(ref m); 
                    }
                    break; 
                case NativeMethods.WM_IME_CHAR: 
                    WmImeChar(ref m);
                    break; 
                case NativeMethods.WM_IME_STARTCOMPOSITION:
                    WmImeStartComposition(ref m);
                    break;
                case NativeMethods.WM_IME_ENDCOMPOSITION: 
                    WmImeEndComposition(ref m);
                    break; 
                case NativeMethods.WM_IME_NOTIFY: 
                    WmImeNotify(ref m);
                    break; 
                case NativeMethods.WM_KILLFOCUS:
                    WmKillFocus(ref m);
                    break;
                case NativeMethods.WM_LBUTTONDBLCLK: 
                    WmMouseDown(ref m, MouseButtons.Left, 2);
                    if (GetStyle(ControlStyles.StandardDoubleClick)) { 
                        SetState(STATE_DOUBLECLICKFIRED, true); 
                    }
                    break; 
                case NativeMethods.WM_LBUTTONDOWN:
                    WmMouseDown(ref m, MouseButtons.Left, 1);
                    break;
                case NativeMethods.WM_LBUTTONUP: 
                    WmMouseUp(ref m, MouseButtons.Left, 1);
                    break; 
                case NativeMethods.WM_MBUTTONDBLCLK: 
                    WmMouseDown(ref m, MouseButtons.Middle, 2);
                    if (GetStyle(ControlStyles.StandardDoubleClick)) { 
                        SetState(STATE_DOUBLECLICKFIRED, true);
                    }
                    break;
                case NativeMethods.WM_MBUTTONDOWN: 
                    WmMouseDown(ref m, MouseButtons.Middle, 1);
                    break; 
                case NativeMethods.WM_MBUTTONUP: 
                    WmMouseUp(ref m, MouseButtons.Middle, 1);
                    break; 
                case NativeMethods.WM_XBUTTONDOWN:
                    WmMouseDown(ref m, GetXButton(NativeMethods.Util.HIWORD(m.WParam)), 1);
                    break;
                case NativeMethods.WM_XBUTTONUP: 
                    WmMouseUp(ref m, GetXButton(NativeMethods.Util.HIWORD(m.WParam)), 1);
                    break; 
                case NativeMethods.WM_XBUTTONDBLCLK: 
                    WmMouseDown(ref m, GetXButton(NativeMethods.Util.HIWORD(m.WParam)), 2);
                    if (GetStyle(ControlStyles.StandardDoubleClick)) { 
                        SetState(STATE_DOUBLECLICKFIRED, true);
                    }
                    break;
                case NativeMethods.WM_MOUSELEAVE: 
                    WmMouseLeave(ref m);
                    break; 
                case NativeMethods.WM_MOUSEMOVE: 
                    WmMouseMove(ref m);
                    break; 
                case NativeMethods.WM_MOUSEWHEEL:
                    WmMouseWheel(ref m);
                    break;
                case NativeMethods.WM_MOVE: 
                    WmMove(ref m);
                    break; 
                case NativeMethods.WM_NOTIFY: 
                    WmNotify(ref m);
                    break; 
                case NativeMethods.WM_NOTIFYFORMAT:
                    WmNotifyFormat(ref m);
                    break;
                case NativeMethods.WM_REFLECT + NativeMethods.WM_NOTIFYFORMAT: 
                    m.Result = (IntPtr)(Marshal.SystemDefaultCharSize == 1 ? NativeMethods.NFR_ANSI : NativeMethods.NFR_UNICODE);
                    break; 
                case NativeMethods.WM_SHOWWINDOW: 
                    WmShowWindow(ref m);
                    break; 
                case NativeMethods.WM_RBUTTONDBLCLK:
                    WmMouseDown(ref m, MouseButtons.Right, 2);
                    if (GetStyle(ControlStyles.StandardDoubleClick)) {
                        SetState(STATE_DOUBLECLICKFIRED, true); 
                    }
                    break; 
                case NativeMethods.WM_RBUTTONDOWN: 
                    WmMouseDown(ref m, MouseButtons.Right, 1);
                    break; 
                case NativeMethods.WM_RBUTTONUP:
                    WmMouseUp(ref m, MouseButtons.Right, 1);
                    break;
                case NativeMethods.WM_SETFOCUS: 
                    WmSetFocus(ref m);
                    break; 
                case NativeMethods.WM_MOUSEHOVER: 
                    WmMouseHover(ref m);
                    break; 
                case NativeMethods.WM_WINDOWPOSCHANGED:
                    WmWindowPosChanged(ref m);
                    break;
                case NativeMethods.WM_QUERYNEWPALETTE: 
                    WmQueryNewPalette(ref m);
                    break; 
                case NativeMethods.WM_UPDATEUISTATE: 
                    WmUpdateUIState(ref m);
                    break; 
                case NativeMethods.WM_PARENTNOTIFY:
                    WmParentNotify(ref m);
                    break;
                default: 
                    // If we received a thread execute message, then execute it.
                    // 
                    if (m.Msg == threadCallbackMessage && m.Msg != 0) { 
                        InvokeMarshaledCallbacks();
                        return; 
                    }
                    else if (m.Msg == Control.WM_GETCONTROLNAME) {
                        WmGetControlName(ref m);
                        return; 
                    }
                    else if (m.Msg == Control.WM_GETCONTROLTYPE) { 
                        WmGetControlType(ref m); 
                        return;
                    } 

                    #if WIN95_SUPPORT
                    // If we have to route the mousewheel messages, do it (this logic was taken
                    // from the MFC sources...) 
                    //
                    if (mouseWheelRoutingNeeded) { 
                        if (m.Msg == mouseWheelMessage) { 
                            Keys keyState = Keys.None;
                            keyState |= (Keys)((UnsafeNativeMethods.GetKeyState((int)Keys.ControlKey) < 0) ? NativeMethods.MK_CONTROL : 0); 
                            keyState |= (Keys)((UnsafeNativeMethods.GetKeyState((int)Keys.ShiftKey) < 0) ? NativeMethods.MK_SHIFT : 0);

                            IntPtr hwndFocus = UnsafeNativeMethods.GetFocus();
 
                            if (hwndFocus == IntPtr.Zero) {
                                SendMessage(m.Msg, (IntPtr)((unchecked((int)(long)m.WParam) << 16) | (int)keyState), m.LParam); 
                            } 
                            else {
                                IntPtr result = IntPtr.Zero; 
                                IntPtr hwndDesktop = UnsafeNativeMethods.GetDesktopWindow();

                                while (result == IntPtr.Zero && hwndFocus != IntPtr.Zero && hwndFocus != hwndDesktop) {
                                    result = UnsafeNativeMethods.SendMessage(new HandleRef(null, hwndFocus), 
                                                                       NativeMethods.WM_MOUSEWHEEL,
                                                                       (unchecked((int)(long)m.WParam) << 16) | (int)keyState, 
                                                                       m.LParam); 
                                    hwndFocus = UnsafeNativeMethods.GetParent(new HandleRef(null, hwndFocus));
                                } 
                            }
                        }
                    }
                    #endif 

                    if (m.Msg == NativeMethods.WM_MOUSEENTER) { 
                        WmMouseEnter(ref m); 
                        break;
                    } 

                    DefWndProc(ref m);
                    break;
            } 

        } 
 
        /// 
        ///      Called when an exception occurs in dispatching messages through 
        ///      the main window procedure.
        /// 
        private void WndProcException(Exception e) {
            Application.OnThreadException(e); 
        }
 
        ///  
        /// 
        ArrangedElementCollection IArrangedElement.Children { 
            get {
                ControlCollection controlsCollection = (ControlCollection)Properties.GetObject(PropControlsCollection);
                if (controlsCollection == null) {
                    return ArrangedElementCollection.Empty; 
                }
                return controlsCollection; 
            } 
        }
 
        /// 
        /// 
        IArrangedElement IArrangedElement.Container {
            get { 
                // This is safe because the IArrangedElement interface is internal
                return ParentInternal; 
            } 
        }
 
        /// 
        /// 
        bool IArrangedElement.ParticipatesInLayout {
            get { return GetState(STATE_VISIBLE); } 
        }
 
        ///  
        /// 
        void IArrangedElement.PerformLayout(IArrangedElement affectedElement, string affectedProperty) { 
            PerformLayout(new LayoutEventArgs(affectedElement, affectedProperty));
        }

        ///  
        /// 
        PropertyStore IArrangedElement.Properties { 
            get { return Properties; } 
        }
 
        // CAREFUL: This really calls SetBoundsCore, not SetBounds.
        /// 
        /// 
        void IArrangedElement.SetBounds(Rectangle bounds, BoundsSpecified specified) { 
            ISite site = Site;
            IComponentChangeService ccs = null; 
            PropertyDescriptor sizeProperty = null; 
            PropertyDescriptor locationProperty = null;
            bool sizeChanged = false; 
            bool locationChanged = false;

            if (site != null && site.DesignMode) {
                ccs = (IComponentChangeService)site.GetService(typeof(IComponentChangeService)); 
                if(ccs != null) {
                    sizeProperty = TypeDescriptor.GetProperties(this)[PropertyNames.Size]; 
                    locationProperty = TypeDescriptor.GetProperties(this)[PropertyNames.Location]; 
                    Debug.Assert(sizeProperty != null && locationProperty != null, "Error retrieving Size/Location properties on Control.");
 
                    try {
                        if (sizeProperty != null && !sizeProperty.IsReadOnly && (bounds.Width != this.Width || bounds.Height != this.Height)) {
                            if (!(site is INestedSite))
                            { 
                                ccs.OnComponentChanging(this, sizeProperty);
                            } 
                            sizeChanged = true; 
                        }
                        if (locationProperty != null && !locationProperty.IsReadOnly && (bounds.X != this.x || bounds.Y != this.y)) { 
                            if (!(site is INestedSite))
                            {
                                ccs.OnComponentChanging(this, locationProperty);
                            } 
                            locationChanged = true;
                        } 
                    } 
                    catch (InvalidOperationException) {
                        // The component change events can throw InvalidOperationException if a change is 
                        // currently not allowed (typically because the doc data in VS is locked).
                        // When this happens, we just eat the exception and proceed with the change.
                    }
                } 
            }
 
            SetBoundsCore(bounds.X, bounds.Y, bounds.Width, bounds.Height, specified); 

            if (site != null && ccs != null) { 
                try {
                    if (sizeChanged)  ccs.OnComponentChanged(this, sizeProperty, null, null);
                    if (locationChanged) ccs.OnComponentChanged(this, locationProperty, null, null);
                } 
                catch (InvalidOperationException) {
                        // The component change events can throw InvalidOperationException if a change is 
                        // currently not allowed (typically because the doc data in VS is locked). 
                        // When this happens, we just eat the exception and proceed with the change.
                } 
            }
        }

 
        /// 
        ///  
        internal sealed class ControlNativeWindow : NativeWindow, IWindowTarget { 
            private Control         control;
            private GCHandle        rootRef;   // We will root the control when we do not want to be elligible for garbage collection. 
            internal IWindowTarget  target;

            internal ControlNativeWindow(Control control) {
                this.control = control; 
                target = this;
            } 
 
            internal Control GetControl() {
                return control; 
            }

            protected override void OnHandleChange() {
                target.OnHandleChange(this.Handle); 
            }
 
            // IWindowTarget method 
            public void OnHandleChange(IntPtr newHandle) {
                control.SetHandle(newHandle); 
            }

            internal void LockReference(bool locked) {
                if (locked) { 
                    if (!rootRef.IsAllocated) {
                        rootRef = GCHandle.Alloc(GetControl(), GCHandleType.Normal); 
                    } 
                }
                else { 
                    if (rootRef.IsAllocated) {
                        rootRef.Free();
                    }
                } 
            }
 
            protected override void OnThreadException(Exception e) { 
                control.WndProcException(e);
            } 

            // IWindowTarget method
            [System.Runtime.TargetedPatchingOptOutAttribute("Performance critical to inline across NGen image boundaries")]
            public void OnMessage(ref Message m) { 
                control.WndProc(ref m);
            } 
 
            internal IWindowTarget WindowTarget {
                get { 
                    return target;
                }
                set {
                    target = value; 
                }
            } 
 
            #if DEBUG
            // We override ToString so in debug asserts that fire for 
            // non-released controls will show what control wasn't released.
            //
            public override string ToString() {
                if (control != null) { 
                    return control.GetType().FullName;
                } 
                return base.ToString(); 
            }
            #endif 

            protected override void WndProc(ref Message m) {
                // There are certain messages that we want to process
                // regardless of what window target we are using.  These 
                // messages cause other messages or state transitions
                // to occur within control. 
                // 
                switch (m.Msg) {
                    case NativeMethods.WM_MOUSELEAVE: 
                        control.UnhookMouseEvent();
                        break;

                    case NativeMethods.WM_MOUSEMOVE: 
                        if (!control.GetState(Control.STATE_TRACKINGMOUSEEVENT)) {
                            control.HookMouseEvent(); 
                            if (!control.GetState(Control.STATE_MOUSEENTERPENDING)) { 
                                control.SendMessage(NativeMethods.WM_MOUSEENTER, 0, 0);
                            } 
                            else {
                                control.SetState(Control.STATE_MOUSEENTERPENDING, false);
                            }
                        } 
                        break;
 
                    case NativeMethods.WM_MOUSEWHEEL: 
                        // TrackMouseEvent's mousehover implementation doesn't watch the wheel
                        // correctly... 
                        //
                        control.ResetMouseEventArgs();
                        break;
                } 

                target.OnMessage(ref m); 
            } 
        }
 
        ///
        /// Explicit support of DropTarget
        ///
        ///  
        /// 
        void IDropTarget.OnDragEnter(DragEventArgs drgEvent) { 
                OnDragEnter(drgEvent); 
        }
        ///  
        /// 
        void IDropTarget.OnDragOver(DragEventArgs drgEvent) {
                OnDragOver(drgEvent);
        } 
        /// 
        ///  
        void IDropTarget.OnDragLeave(EventArgs e) { 
                OnDragLeave(e);
        } 
        /// 
        /// 
        void IDropTarget.OnDragDrop(DragEventArgs drgEvent) {
                OnDragDrop(drgEvent); 
        }
 
        /// 
        /// Explicit support of DropSource
        /// 
        /// 
        /// 
        void ISupportOleDropSource.OnGiveFeedback(GiveFeedbackEventArgs giveFeedbackEventArgs)  {
                OnGiveFeedback(giveFeedbackEventArgs); 
        }
        ///  
        ///  
        void ISupportOleDropSource.OnQueryContinueDrag(QueryContinueDragEventArgs queryContinueDragEventArgs) {
                OnQueryContinueDrag(queryContinueDragEventArgs); 
        }

        /// 
        ///  
        ///     Collection of controls...
        ///  
        [ 
            ListBindable(false), ComVisible(false)
        ] 
        public class ControlCollection : ArrangedElementCollection, IList, ICloneable {

            private Control owner;
 
            /// A caching mechanism for key accessor
            /// We use an index here rather than control so that we don't have lifetime 
            /// issues by holding on to extra references. 
            /// Note this is not Thread Safe - but [....] has to be run in a STA anyways.
            private int lastAccessedIndex = -1; 


            /// 
            ///  
            ///    [To be supplied.]
            ///  
            public ControlCollection(Control owner) { 
                this.owner = owner;
            } 

            /// 
            /// 
            ///     Returns true if the collection contains an item with the specified key, false otherwise. 
            /// 
            public virtual bool ContainsKey(string key) { 
               return IsValidIndex(IndexOfKey(key)); 
            }
 
            /// 
            /// 
            ///    Adds a child control to this control. The control becomes the last control in
            ///       the child control list. If the control is already a child of another control it 
            ///       is first removed from that control.
            ///  
            public virtual void Add(Control value) { 
                if (value == null)
                    return; 
                if (value.GetTopLevel()) {
                    throw new ArgumentException(SR.GetString(SR.TopLevelControlAdd));
                }
 
                // Verify that the control being added is on the same thread as
                // us...or our parent chain. 
                // 
                if (owner.CreateThreadId != value.CreateThreadId) {
                    throw new ArgumentException(SR.GetString(SR.AddDifferentThreads)); 
                }

                CheckParentingCycle(owner, value);
 
                if (value.parent == owner) {
                    value.SendToBack(); 
                    return; 
                }
 
                // Remove the new control from its old parent (if any)
                //
                if (value.parent != null) {
                    value.parent.Controls.Remove(value); 
                }
 
                // Add the control 
                //
                InnerList.Add(value); 

                if (value.tabIndex == -1) {

                    // Find the next highest tab index 
                    //
                    int nextTabIndex = 0; 
                    for (int c = 0; c < (Count - 1); c++) { 
                        int t = this[c].TabIndex;
                        if (nextTabIndex <= t) { 
                            nextTabIndex = t + 1;
                        }
                    }
                    value.tabIndex = nextTabIndex; 
                }
 
                // if we don't suspend layout, AssignParent will indirectly trigger a layout event 
                // before we're ready (AssignParent will fire a PropertyChangedEvent("Visible"), which calls PerformLayout)
                // 
#if DEBUG
                int dbgLayoutCheck = owner.LayoutSuspendCount;
#endif
                owner.SuspendLayout(); 

                try { 
                    Control oldParent = value.parent; 
                    try {
                        // AssignParent calls into user code - this could throw, which 
                        // would make us short-circuit the rest of the reparenting logic.
                        // you could end up with a control half reparented.
                        value.AssignParent(owner);
                    } 
                    finally {
                        if (oldParent != value.parent && (owner.state & STATE_CREATED) != 0) { 
                            value.SetParentHandle(owner.InternalHandle); 
                            if (value.Visible) {
                                value.CreateControl(); 
                            }
                        }
                    }
 
                    value.InitLayout();
                } 
                finally { 
                    owner.ResumeLayout(false);
#if DEBUG 
                    owner.AssertLayoutSuspendCount(dbgLayoutCheck);
#endif

                } 

                // Not putting in the finally block, as it would eat the original 
                // exception thrown from AssignParent if the following throws an exception. 
                LayoutTransaction.DoLayout(owner, value, PropertyNames.Parent);
                owner.OnControlAdded(new ControlEventArgs(value)); 


            }
 
            /// 
            ///  
            int IList.Add(object control) { 
                if (control is Control) {
                    Add((Control)control); 
                    return IndexOf((Control)control);
                }
                else {
                    throw new ArgumentException(SR.GetString(SR.ControlBadControl), "control"); 
                }
            } 
 
            /// 
            ///  
            ///    [To be supplied.]
            /// 
            [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
            public virtual void AddRange(Control[] controls) { 
                if (controls == null) {
                    throw new ArgumentNullException("controls"); 
                } 
                if (controls.Length > 0) {
#if DEBUG 
                    int dbgLayoutCheck = owner.LayoutSuspendCount;
#endif
                    owner.SuspendLayout();
                    try { 
                        for(int i=0;i < controls.Length; ++i) {
                            Add(controls[i]); 
                        } 
                    }
                    finally { 
                        owner.ResumeLayout(true);
                    }
#if DEBUG
                    owner.AssertLayoutSuspendCount(dbgLayoutCheck); 
#endif
                } 
            } 

            ///  
            /// 
            object ICloneable.Clone() {
                // Use CreateControlInstance so we get the same type of ControlCollection, but whack the
                // owner so adding controls to this new collection does not affect the control we cloned from. 
                ControlCollection ccOther = owner.CreateControlsInstance();
 
                // We add using InnerList to prevent unnecessary parent cycle checks, etc. 
                ccOther.InnerList.AddRange(this);
                return ccOther; 
            }

            /// 
            ///  
            ///    [To be supplied.]
            ///  
            public bool Contains(Control control) { 
                return InnerList.Contains(control);
            } 


            /// 
            ///  
            ///     Searches for Controls by their Name property, builds up an array
            ///           of all the controls that match. 
            ///      
            /// 
            public Control[] Find(string key, bool searchAllChildren) { 
                if (String.IsNullOrEmpty(key)) {
                   throw new System.ArgumentNullException("key", SR.GetString(SR.FindKeyMayNotBeEmptyOrNull));
                }
 
                ArrayList foundControls =  FindInternal(key, searchAllChildren, this, new ArrayList());
 
                // Make this a stongly typed collection. 
                Control[] stronglyTypedFoundControls = new Control[foundControls.Count];
                foundControls.CopyTo(stronglyTypedFoundControls, 0); 

                return stronglyTypedFoundControls;
            }
 
            /// 
            ///  
            ///     Searches for Controls by their Name property, builds up an array list 
            ///           of all the controls that match.
            ///      
            /// 
            /// 
            private ArrayList FindInternal(string key, bool searchAllChildren, ControlCollection controlsToLookIn, ArrayList foundControls) {
                if ((controlsToLookIn == null) || (foundControls == null)) { 
                    return null;
                } 
 
                try {
                    // Perform breadth first search - as it's likely people will want controls belonging 
                    // to the same parent close to each other.

                    for (int i = 0; i < controlsToLookIn.Count; i++) {
                          if (controlsToLookIn[i] == null){ 
                              continue;
                          } 
 
                          if (WindowsFormsUtils.SafeCompareStrings(controlsToLookIn[i].Name, key, /* ignoreCase = */ true)) {
                               foundControls.Add(controlsToLookIn[i]); 
                          }
                    }

                    // Optional recurive search for controls in child collections. 

                    if (searchAllChildren){ 
                        for (int i = 0; i < controlsToLookIn.Count; i++) { 
                            if (controlsToLookIn[i] == null){
                                continue; 
                            }
                            if ((controlsToLookIn[i].Controls != null) && controlsToLookIn[i].Controls.Count > 0){
                                // if it has a valid child collecion, append those results to our collection
                                foundControls = FindInternal(key, searchAllChildren, controlsToLookIn[i].Controls, foundControls); 
                            }
                        } 
                    } 
                }
                catch (Exception e) { 
                    if (ClientUtils.IsSecurityOrCriticalException(e)) {
                        throw;
                    }
                } 
                return foundControls;
            } 
 
            [System.Runtime.TargetedPatchingOptOutAttribute("Performance critical to inline across NGen image boundaries")]
            public override IEnumerator GetEnumerator() { 
                return new ControlCollectionEnumerator(this);
            }

            ///  
            /// 
            ///    [To be supplied.] 
            ///  
            public int IndexOf(Control control) {
                return InnerList.IndexOf(control); 
            }

            /// 
            ///  
            ///     The zero-based index of the first occurrence of value within the entire CollectionBase, if found; otherwise, -1.
            ///  
            public virtual int IndexOfKey(String key) { 
                // Step 0 - Arg validation
                if (String.IsNullOrEmpty(key)) { 
                    return -1; // we dont support empty or null keys.
                }

                // step 1 - check the last cached item 
                if (IsValidIndex(lastAccessedIndex))
                { 
                    if (WindowsFormsUtils.SafeCompareStrings(this[lastAccessedIndex].Name, key, /* ignoreCase = */ true)) { 
                        return lastAccessedIndex;
                    } 
                }

                // step 2 - search for the item
                for (int i = 0; i < this.Count; i ++) { 
                    if (WindowsFormsUtils.SafeCompareStrings(this[i].Name, key, /* ignoreCase = */ true)) {
                        lastAccessedIndex = i; 
                        return i; 
                    }
                } 

                // step 3 - we didn't find it.  Invalidate the last accessed index and return -1.
                lastAccessedIndex = -1;
                return -1; 
            }
 
            ///  
            /// 
            ///     Determines if the index is valid for the collection. 
            /// 
            /// 
            private bool IsValidIndex(int index) {
                return ((index >= 0) && (index < this.Count)); 
            }
 
            ///  
            /// 
            ///     Who owns this control collection. 
            /// 
            /// 
            public Control Owner {
                get { 
                    return owner;
                } 
            } 

            ///  
            /// 
            ///     Removes control from this control. Inheriting controls should call
            ///     base.remove to ensure that the control is removed.
            ///  
            public virtual void Remove(Control value) {
 
                // Sanity check parameter 
                //
                if (value == null) { 
                    return;     // Don't do anything
                }

                if (value.ParentInternal == owner) { 
                    Debug.Assert(owner != null);
 
                    value.SetParentHandle(IntPtr.Zero); 

                    // Remove the control from the internal control array 
                    //
                    InnerList.Remove(value);
                    value.AssignParent(null);
                    LayoutTransaction.DoLayout(owner, value, PropertyNames.Parent); 
                    owner.OnControlRemoved(new ControlEventArgs(value));
 
                    // ContainerControl needs to see it needs to find a new ActiveControl. 
                    ContainerControl cc = owner.GetContainerControlInternal() as ContainerControl;
                    if (cc != null) 
                    {
                        cc.AfterControlRemoved(value, owner);
                    }
                } 
            }
 
            ///  
            /// 
            void IList.Remove(object control) { 
                if (control is Control) {
                    Remove((Control)control);
                }
            } 

            ///  
            ///  
            ///    [To be supplied.]
            ///  
            public void RemoveAt(int index) {
                Remove(this[index]);
            }
 
            /// 
            ///  
            ///     Removes the child control with the specified key. 
            /// 
            public virtual void RemoveByKey(string key) { 
                int index = IndexOfKey(key);
                if (IsValidIndex(index)) {
                    RemoveAt(index);
                } 
            }
 
            ///  
            /// 
            ///     Retrieves the child control with the specified index. 
            /// 
            public new virtual Control this[int index] {
                get {
                    //do some bounds checking here... 
                    if (index < 0 || index >= Count) {
                        throw new ArgumentOutOfRangeException("index", SR.GetString(SR.IndexOutOfRange, index.ToString(CultureInfo.CurrentCulture))); 
                    } 

                    Control control = (Control) InnerList[index]; 
                    Debug.Assert(control != null, "Why are we returning null controls from a valid index?");
                    return control;
                }
            } 

            ///  
            ///  
            ///     Retrieves the child control with the specified key.
            ///  
            public virtual Control this[string key] {
                get {
                    // We do not support null and empty string as valid keys.
                    if (String.IsNullOrEmpty(key)) { 
                        return null;
                    } 
 
                    // Search for the key in our collection
                    int index = IndexOfKey(key); 
                    if (IsValidIndex(index)) {
                        return this[index];
                    }
                    else { 
                        return null;
                    } 
 
                }
            } 


            /// 
            ///  
            ///    [To be supplied.]
            ///  
            public virtual void Clear() { 
#if DEBUG
                int layoutSuspendCount = owner.LayoutSuspendCount; 
#endif
                owner.SuspendLayout();
                // clear all preferred size caches in the tree -
                // inherited fonts could go away, etc. 
                CommonProperties.xClearAllPreferredSizeCaches(owner);
 
                try { 
                    while (Count != 0)
                        RemoveAt(Count - 1); 
                } finally {
                    owner.ResumeLayout();
#if DEBUG
                    Debug.Assert(owner.LayoutSuspendCount == layoutSuspendCount, "Suspend/Resume layout mismatch!"); 
#endif
                } 
            } 

            ///  
            /// 
            ///     Retrieves the index of the specified
            ///     child control in this array.  An ArgumentException
            ///     is thrown if child is not parented to this 
            ///     Control.
            ///  
            public int GetChildIndex(Control child) { 
                return GetChildIndex(child, true);
            } 

            /// 
            /// 
            ///     Retrieves the index of the specified 
            ///     child control in this array.  An ArgumentException
            ///     is thrown if child is not parented to this 
            ///     Control. 
            /// 
            public virtual int GetChildIndex(Control child, bool throwException) { 
                int index = IndexOf(child);
                if (index == -1 && throwException) {
                    throw new ArgumentException(SR.GetString(SR.ControlNotChild));
                } 
                return index;
            } 
 
            /// 
            ///     This is internal virtual method so that "Readonly Collections" can override this and throw as they should not allow changing 
            ///     the child control indices.
            /// 
            /// 
            internal virtual void SetChildIndexInternal(Control child, int newIndex) 
            {
                // Sanity check parameters 
                // 
                if (child == null) {
                    throw new ArgumentNullException("child"); 
                }

                int currentIndex = GetChildIndex(child);
 
                if (currentIndex == newIndex) {
                    return; 
                } 

                if (newIndex >= Count || newIndex == -1) { 
                    newIndex = Count - 1;
                }

                MoveElement(child, currentIndex, newIndex); 
                child.UpdateZOrder();
 
                LayoutTransaction.DoLayout(owner, child, PropertyNames.ChildIndex); 

            } 

            /// 
            /// 
            ///     Sets the index of the specified 
            ///     child control in this array.  An ArgumentException
            ///     is thrown if child is not parented to this 
            ///     Control. 
            /// 
            public virtual void SetChildIndex(Control child, int newIndex) { 
                SetChildIndexInternal(child, newIndex);
            }

            // COMPAT: VSWhidbey 448276 
            // This is the same as WinformsUtils.ArraySubsetEnumerator
            // however since we're no longer an array, we've gotta employ a 
            // special version of this. 
            private class ControlCollectionEnumerator : IEnumerator {
                private ControlCollection controls; 
                private int current;
                private int originalCount;

                public ControlCollectionEnumerator(ControlCollection controls) { 
                    this.controls = controls;
                    this.originalCount = controls.Count; 
                    current = -1; 
                }
 
                public bool MoveNext() {
                    // VSWhidbey 448276
                    // We have to use Controls.Count here because someone could have deleted
                    // an item from the array. 
                    //
                    // this can happen if someone does: 
                    //     foreach (Control c in Controls) { c.Dispose(); } 
                    //
                    // We also dont want to iterate past the original size of the collection 
                    //
                    // this can happen if someone does
                    //     foreach (Control c in Controls) { c.Controls.Add(new Label()); }
 
                    if (current < controls.Count - 1 && current < originalCount - 1) {
                        current++; 
                        return true; 
                    }
                    else { 
                        return false;
                    }
                }
 
                public void Reset() {
                    current = -1; 
                } 

                public object Current { 
                    [System.Runtime.TargetedPatchingOptOutAttribute("Performance critical to inline across NGen image boundaries")]
                    get {
                        if (current == -1) {
                            return null; 
                        }
                        else { 
                            return controls[current]; 
                        }
                    } 
                }
            }

        } 

        ///  
        ///  
        /// 
        ///  
        int UnsafeNativeMethods.IOleControl.GetControlInfo(NativeMethods.tagCONTROLINFO pCI) {
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:GetControlInfo");

            pCI.cb = Marshal.SizeOf(typeof(NativeMethods.tagCONTROLINFO)); 
            pCI.hAccel = IntPtr.Zero;
            pCI.cAccel = 0; 
            pCI.dwFlags = 0; 

            if (IsInputKey(Keys.Return)) { 
                pCI.dwFlags |= NativeMethods.CTRLINFO_EATS_RETURN;
            }
            if (IsInputKey(Keys.Escape)) {
                pCI.dwFlags |= NativeMethods.CTRLINFO_EATS_ESCAPE; 
            }
 
            ActiveXInstance.GetControlInfo(pCI); 
            return NativeMethods.S_OK;
        } 

        /// 
        /// 
        ///  
        /// 
        int UnsafeNativeMethods.IOleControl.OnMnemonic(ref NativeMethods.MSG pMsg) { 
 
            // If we got a mnemonic here, then the appropriate control will focus itself which
            // will cause us to become UI active. 
            //
            bool processed = ProcessMnemonic((char)pMsg.wParam);
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:OnMnemonic processed: " + processed.ToString());
            return NativeMethods.S_OK; 
        }
 
        ///  
        /// 
        ///  
        /// 
        int UnsafeNativeMethods.IOleControl.OnAmbientPropertyChange(int dispID) {
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:OnAmbientPropertyChange.  Dispid: " + dispID);
            Debug.Indent(); 
            ActiveXInstance.OnAmbientPropertyChange(dispID);
            Debug.Unindent(); 
            return NativeMethods.S_OK; 
        }
 
        /// 
        /// 
        /// 
        ///  
        int UnsafeNativeMethods.IOleControl.FreezeEvents(int bFreeze) {
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:FreezeEvents.  Freeze: " + bFreeze); 
            ActiveXInstance.EventsFrozen = (bFreeze != 0); 
            Debug.Assert(ActiveXInstance.EventsFrozen == (bFreeze != 0), "Failed to set EventsFrozen correctly");
            return NativeMethods.S_OK; 
        }

        /// 
        ///  
        /// 
        ///  
        int UnsafeNativeMethods.IOleInPlaceActiveObject.GetWindow(out IntPtr hwnd) { 
            return((UnsafeNativeMethods.IOleInPlaceObject)this).GetWindow(out hwnd);
        } 

        /// 
        /// 
        ///  
        /// 
        void UnsafeNativeMethods.IOleInPlaceActiveObject.ContextSensitiveHelp(int fEnterMode) { 
            ((UnsafeNativeMethods.IOleInPlaceObject)this).ContextSensitiveHelp(fEnterMode); 
        }
 
        /// 
        /// 
        /// 
        ///  
        int UnsafeNativeMethods.IOleInPlaceActiveObject.TranslateAccelerator(ref NativeMethods.MSG lpmsg) {
            return ActiveXInstance.TranslateAccelerator(ref lpmsg); 
        } 

        ///  
        /// 
        /// 
        /// 
        void UnsafeNativeMethods.IOleInPlaceActiveObject.OnFrameWindowActivate(bool fActivate) { 
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:OnFrameWindowActivate");
            OnFrameWindowActivate(fActivate); 
            // return NativeMethods.S_OK; 
        }
 
        /// 
        /// 
        /// 
        ///  
        void UnsafeNativeMethods.IOleInPlaceActiveObject.OnDocWindowActivate(int fActivate) {
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:OnDocWindowActivate.  Activate: " + fActivate.ToString(CultureInfo.InvariantCulture)); 
            Debug.Indent(); 
            ActiveXInstance.OnDocWindowActivate(fActivate);
            Debug.Unindent(); 
        }

        /// 
        ///  
        /// 
        ///  
        void UnsafeNativeMethods.IOleInPlaceActiveObject.ResizeBorder(NativeMethods.COMRECT prcBorder, UnsafeNativeMethods.IOleInPlaceUIWindow pUIWindow, bool fFrameWindow) { 
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:ResizesBorder");
            // return NativeMethods.S_OK; 
        }

        /// 
        ///  
        /// 
        ///  
        void UnsafeNativeMethods.IOleInPlaceActiveObject.EnableModeless(int fEnable) { 
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:EnableModeless");
            // return NativeMethods.S_OK; 
        }

        /// 
        ///  
        /// 
        ///  
        int UnsafeNativeMethods.IOleInPlaceObject.GetWindow(out IntPtr hwnd) { 
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:GetWindow");
            int hr = ActiveXInstance.GetWindow(out hwnd); 
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "\twin == " + hwnd);
            return hr;
        }
 
        /// 
        ///  
        ///  
        /// 
        void UnsafeNativeMethods.IOleInPlaceObject.ContextSensitiveHelp(int fEnterMode) { 
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:ContextSensitiveHelp.  Mode: " + fEnterMode.ToString(CultureInfo.InvariantCulture));
            if (fEnterMode != 0) {
                OnHelpRequested(new HelpEventArgs(Control.MousePosition));
            } 
        }
 
        ///  
        /// 
        ///  
        /// 
        void UnsafeNativeMethods.IOleInPlaceObject.InPlaceDeactivate() {
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:InPlaceDeactivate");
            Debug.Indent(); 
            ActiveXInstance.InPlaceDeactivate();
            Debug.Unindent(); 
        } 

        ///  
        /// 
        /// 
        /// 
        int UnsafeNativeMethods.IOleInPlaceObject.UIDeactivate() { 
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:UIDeactivate");
            return ActiveXInstance.UIDeactivate(); 
        } 

        ///  
        /// 
        /// 
        /// 
        void UnsafeNativeMethods.IOleInPlaceObject.SetObjectRects(NativeMethods.COMRECT lprcPosRect, NativeMethods.COMRECT lprcClipRect) { 
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:SetObjectRects(" + lprcClipRect.left + ", " + lprcClipRect.top + ", " + lprcClipRect.right + ", " + lprcClipRect.bottom + ")");
            Debug.Indent(); 
            ActiveXInstance.SetObjectRects(lprcPosRect, lprcClipRect); 
            Debug.Unindent();
        } 

        /// 
        /// 
        ///  
        /// 
        void UnsafeNativeMethods.IOleInPlaceObject.ReactivateAndUndo() { 
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:ReactivateAndUndo"); 
            // return NativeMethods.S_OK;
        } 

        /// 
        /// 
        ///  
        /// 
        int UnsafeNativeMethods.IOleObject.SetClientSite(UnsafeNativeMethods.IOleClientSite pClientSite) { 
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:SetClientSite"); 
            ActiveXInstance.SetClientSite(pClientSite);
            return NativeMethods.S_OK; 
        }

        /// 
        ///  
        /// 
        ///  
        UnsafeNativeMethods.IOleClientSite UnsafeNativeMethods.IOleObject.GetClientSite() { 
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:GetClientSite");
            return ActiveXInstance.GetClientSite(); 
        }

        /// 
        ///  
        /// 
        ///  
        int UnsafeNativeMethods.IOleObject.SetHostNames(string szContainerApp, string szContainerObj) { 
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:SetHostNames");
            // Since ActiveX controls never "open" for editing, we shouldn't need 
            // to store these.
            return NativeMethods.S_OK;
        }
 
        /// 
        ///  
        ///  
        /// 
        int UnsafeNativeMethods.IOleObject.Close(int dwSaveOption) { 
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:Close. Save option: " + dwSaveOption);
            ActiveXInstance.Close(dwSaveOption);
            return NativeMethods.S_OK;
        } 

        ///  
        ///  
        /// 
        ///  
        int UnsafeNativeMethods.IOleObject.SetMoniker(int dwWhichMoniker, Object pmk) {
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:SetMoniker");
            return NativeMethods.E_NOTIMPL;
        } 

        ///  
        ///  
        /// 
        ///  
        int UnsafeNativeMethods.IOleObject.GetMoniker(int dwAssign, int dwWhichMoniker, out Object moniker) {
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:GetMoniker");
            moniker = null;
            return NativeMethods.E_NOTIMPL; 
        }
 
        ///  
        /// 
        ///  
        /// 
        int UnsafeNativeMethods.IOleObject.InitFromData(IComDataObject pDataObject, int fCreation, int dwReserved) {
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:InitFromData");
            return NativeMethods.E_NOTIMPL; 
        }
 
        ///  
        /// 
        ///  
        /// 
        int UnsafeNativeMethods.IOleObject.GetClipboardData(int dwReserved, out IComDataObject data) {
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:GetClipboardData");
            data = null; 
            return NativeMethods.E_NOTIMPL;
        } 
 
        /// 
        ///  
        /// 
        /// 
        int UnsafeNativeMethods.IOleObject.DoVerb(int iVerb, IntPtr lpmsg, UnsafeNativeMethods.IOleClientSite pActiveSite, int lindex, IntPtr hwndParent, NativeMethods.COMRECT lprcPosRect) {
 
            // In Office they are internally casting an iverb to a short and not
            // doing the proper sign extension.  So, we do it here. 
            // 
            short sVerb = unchecked((short)iVerb);
            iVerb = (int)sVerb; 

#if DEBUG
            if (CompModSwitches.ActiveX.TraceInfo) {
                Debug.WriteLine("AxSource:DoVerb {"); 
                Debug.WriteLine("     verb: " + iVerb);
                Debug.WriteLine("     msg: " + lpmsg); 
                Debug.WriteLine("     activeSite: " + pActiveSite); 
                Debug.WriteLine("     index: " + lindex);
                Debug.WriteLine("     hwndParent: " + hwndParent); 
                Debug.WriteLine("     posRect: " + lprcPosRect);
            }
#endif
            Debug.Indent(); 
            try {
                ActiveXInstance.DoVerb(iVerb, lpmsg, pActiveSite, lindex, hwndParent, lprcPosRect); 
            } 
            catch (Exception e) {
                Debug.Fail("Exception occurred during DoVerb(" + iVerb + ") " + e.ToString()); 
                throw;
            }
            finally {
                Debug.Unindent(); 
                Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "}");
            } 
            return NativeMethods.S_OK; 
        }
 
        /// 
        /// 
        /// 
        ///  
        int UnsafeNativeMethods.IOleObject.EnumVerbs(out UnsafeNativeMethods.IEnumOLEVERB e) {
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:EnumVerbs"); 
            return ActiveXImpl.EnumVerbs(out e); 
        }
 
        /// 
        /// 
        /// 
        ///  
        int UnsafeNativeMethods.IOleObject.OleUpdate() {
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:OleUpdate"); 
            return NativeMethods.S_OK; 
        }
 
        /// 
        /// 
        /// 
        ///  
        int UnsafeNativeMethods.IOleObject.IsUpToDate() {
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:IsUpToDate"); 
            return NativeMethods.S_OK; 
        }
 
        /// 
        /// 
        /// 
        ///  
        int UnsafeNativeMethods.IOleObject.GetUserClassID(ref Guid pClsid) {
            pClsid = GetType().GUID; 
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:GetUserClassID.  ClassID: " + pClsid.ToString()); 
            return NativeMethods.S_OK;
        } 

        /// 
        /// 
        ///  
        /// 
        int UnsafeNativeMethods.IOleObject.GetUserType(int dwFormOfType, out string userType) { 
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:GetUserType"); 
            if (dwFormOfType == NativeMethods.USERCLASSTYPE_FULL) {
                userType = GetType().FullName; 
            }
            else {
                userType = GetType().Name;
            } 
            return NativeMethods.S_OK;
        } 
 
        /// 
        ///  
        /// 
        /// 
        int UnsafeNativeMethods.IOleObject.SetExtent(int dwDrawAspect, NativeMethods.tagSIZEL pSizel) {
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:SetExtent(" + pSizel.cx + ", " + pSizel.cy + ")"); 
            Debug.Indent();
            ActiveXInstance.SetExtent(dwDrawAspect, pSizel); 
            Debug.Unindent(); 
            return NativeMethods.S_OK;
        } 

        /// 
        /// 
        ///  
        /// 
        int UnsafeNativeMethods.IOleObject.GetExtent(int dwDrawAspect, NativeMethods.tagSIZEL pSizel) { 
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:GetExtent.  Aspect: " + dwDrawAspect.ToString(CultureInfo.InvariantCulture)); 
            Debug.Indent();
            ActiveXInstance.GetExtent(dwDrawAspect, pSizel); 
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "value: " + pSizel.cx + ", " + pSizel.cy);
            Debug.Unindent();
            return NativeMethods.S_OK;
        } 

        ///  
        ///  
        /// 
        ///  
        int UnsafeNativeMethods.IOleObject.Advise(IAdviseSink pAdvSink, out int cookie) {
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:Advise");
            cookie = ActiveXInstance.Advise(pAdvSink);
            return NativeMethods.S_OK; 
        }
 
        ///  
        /// 
        ///  
        /// 
        int UnsafeNativeMethods.IOleObject.Unadvise(int dwConnection) {
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:Unadvise");
            Debug.Indent(); 
            ActiveXInstance.Unadvise(dwConnection);
            Debug.Unindent(); 
            return NativeMethods.S_OK; 
        }
 
        /// 
        /// 
        /// 
        ///  
        int UnsafeNativeMethods.IOleObject.EnumAdvise(out IEnumSTATDATA e) {
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:EnumAdvise"); 
            e = null; 
            return NativeMethods.E_NOTIMPL;
        } 

        /// 
        /// 
        ///  
        /// 
        int UnsafeNativeMethods.IOleObject.GetMiscStatus(int dwAspect, out int cookie) { 
            if ((dwAspect & NativeMethods.DVASPECT_CONTENT) != 0) { 
                int status = NativeMethods.OLEMISC_ACTIVATEWHENVISIBLE | NativeMethods.OLEMISC_INSIDEOUT | NativeMethods.OLEMISC_SETCLIENTSITEFIRST;
 
                if (GetStyle(ControlStyles.ResizeRedraw)) {
                    status |= NativeMethods.OLEMISC_RECOMPOSEONRESIZE;
                }
 
                if (this is IButtonControl) {
                    status |= NativeMethods.OLEMISC_ACTSLIKEBUTTON; 
                } 

                Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:GetMiscStatus. Status: " + status.ToString(CultureInfo.InvariantCulture)); 
                cookie = status;
            }
            else {
                Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:GetMiscStatus.  Status: ERROR, wrong aspect."); 
                cookie = 0;
                return NativeMethods.DV_E_DVASPECT; 
            } 
            return NativeMethods.S_OK;
        } 

        /// 
        /// 
        ///  
        /// 
        int UnsafeNativeMethods.IOleObject.SetColorScheme(NativeMethods.tagLOGPALETTE pLogpal) { 
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:SetColorScheme"); 
            return NativeMethods.S_OK;
        } 

        /// 
        /// 
        ///  
        /// 
        int UnsafeNativeMethods.IOleWindow.GetWindow(out IntPtr hwnd) { 
            return((UnsafeNativeMethods.IOleInPlaceObject)this).GetWindow(out hwnd); 
        }
 
        /// 
        /// 
        /// 
        ///  
        void UnsafeNativeMethods.IOleWindow.ContextSensitiveHelp(int fEnterMode) {
            ((UnsafeNativeMethods.IOleInPlaceObject)this).ContextSensitiveHelp(fEnterMode); 
        } 

        ///  
        /// 
        /// 
        /// 
        void UnsafeNativeMethods.IPersist.GetClassID(out Guid pClassID) { 
            pClassID = GetType().GUID;
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:IPersist.GetClassID.  ClassID: " + pClassID.ToString()); 
        } 

        ///  
        /// 
        /// 
        /// 
        void UnsafeNativeMethods.IPersistPropertyBag.InitNew() { 
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:IPersistPropertyBag.InitNew");
        } 
 
        /// 
        ///  
        /// 
        /// 
        void UnsafeNativeMethods.IPersistPropertyBag.GetClassID(out Guid pClassID) {
            pClassID = GetType().GUID; 
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:IPersistPropertyBag.GetClassID.  ClassID: " + pClassID.ToString());
        } 
 
        /// 
        ///  
        /// 
        /// 
        void UnsafeNativeMethods.IPersistPropertyBag.Load(UnsafeNativeMethods.IPropertyBag pPropBag, UnsafeNativeMethods.IErrorLog pErrorLog) {
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:Load (IPersistPropertyBag)"); 
            Debug.Indent();
            ActiveXInstance.Load(pPropBag, pErrorLog); 
            Debug.Unindent(); 
        }
 
        /// 
        /// 
        /// 
        ///  
        void UnsafeNativeMethods.IPersistPropertyBag.Save(UnsafeNativeMethods.IPropertyBag pPropBag, bool fClearDirty, bool fSaveAllProperties) {
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:Save (IPersistPropertyBag)"); 
            Debug.Indent(); 
            ActiveXInstance.Save(pPropBag, fClearDirty, fSaveAllProperties);
            Debug.Unindent(); 
        }

        /// 
        ///  
        /// 
        ///  
        void UnsafeNativeMethods.IPersistStorage.GetClassID(out Guid pClassID) { 
            pClassID = GetType().GUID;
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:IPersistStorage.GetClassID.  ClassID: " + pClassID.ToString()); 
        }

        /// 
        ///  
        /// 
        ///  
        int UnsafeNativeMethods.IPersistStorage.IsDirty() { 
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:IPersistStorage.IsDirty");
            return ActiveXInstance.IsDirty(); 
        }

        /// 
        ///  
        /// 
        ///  
        void UnsafeNativeMethods.IPersistStorage.InitNew(UnsafeNativeMethods.IStorage pstg) { 
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:IPersistStorage.InitNew");
        } 

        /// 
        /// 
        ///  
        /// 
        int UnsafeNativeMethods.IPersistStorage.Load(UnsafeNativeMethods.IStorage pstg) { 
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:IPersistStorage.Load"); 
            Debug.Indent();
            ActiveXInstance.Load(pstg); 
            Debug.Unindent();
            return NativeMethods.S_OK;
        }
 
        /// 
        ///  
        ///  
        /// 
        void UnsafeNativeMethods.IPersistStorage.Save(UnsafeNativeMethods.IStorage pstg, bool fSameAsLoad) { 
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:IPersistStorage.Save");
            Debug.Indent();
            ActiveXInstance.Save(pstg, fSameAsLoad);
            Debug.Unindent(); 
        }
 
        ///  
        /// 
        ///  
        /// 
        void UnsafeNativeMethods.IPersistStorage.SaveCompleted(UnsafeNativeMethods.IStorage pStgNew) {
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:IPersistStorage.SaveCompleted");
        } 

        ///  
        ///  
        /// 
        ///  
        void UnsafeNativeMethods.IPersistStorage.HandsOffStorage() {
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:IPersistStorage.HandsOffStorage");
        }
 
        /// 
        ///  
        ///  
        /// 
        void UnsafeNativeMethods.IPersistStreamInit.GetClassID(out Guid pClassID) { 
            pClassID = GetType().GUID;
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:IPersistStreamInit.GetClassID.  ClassID: " + pClassID.ToString());
        }
 
        /// 
        ///  
        ///  
        /// 
        int UnsafeNativeMethods.IPersistStreamInit.IsDirty() { 
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:IPersistStreamInit.IsDirty");
            return ActiveXInstance.IsDirty();
        }
 
        /// 
        ///  
        ///  
        /// 
        void UnsafeNativeMethods.IPersistStreamInit.Load(UnsafeNativeMethods.IStream pstm) { 
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:IPersistStreamInit.Load");
            Debug.Indent();
            ActiveXInstance.Load(pstm);
            Debug.Unindent(); 
        }
 
        ///  
        /// 
        ///  
        /// 
        void UnsafeNativeMethods.IPersistStreamInit.Save(UnsafeNativeMethods.IStream pstm, bool fClearDirty) {
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:IPersistStreamInit.Save");
            Debug.Indent(); 
            ActiveXInstance.Save(pstm, fClearDirty);
            Debug.Unindent(); 
        } 

        ///  
        /// 
        /// 
        /// 
        void UnsafeNativeMethods.IPersistStreamInit.GetSizeMax(long pcbSize) { 
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:GetSizeMax");
        } 
 
        /// 
        ///  
        /// 
        /// 
        void UnsafeNativeMethods.IPersistStreamInit.InitNew() {
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:IPersistStreamInit.InitNew"); 
        }
 
        ///  
        /// 
        ///  
        /// 
        void UnsafeNativeMethods.IQuickActivate.QuickActivate(UnsafeNativeMethods.tagQACONTAINER pQaContainer, UnsafeNativeMethods.tagQACONTROL pQaControl) {
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:QuickActivate");
            Debug.Indent(); 
            ActiveXInstance.QuickActivate(pQaContainer, pQaControl);
            Debug.Unindent(); 
        } 

        ///  
        /// 
        /// 
        /// 
        void UnsafeNativeMethods.IQuickActivate.SetContentExtent(NativeMethods.tagSIZEL pSizel) { 
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:SetContentExtent");
            Debug.Indent(); 
            ActiveXInstance.SetExtent(NativeMethods.DVASPECT_CONTENT, pSizel); 
            Debug.Unindent();
        } 

        /// 
        /// 
        ///  
        /// 
        void UnsafeNativeMethods.IQuickActivate.GetContentExtent(NativeMethods.tagSIZEL pSizel) { 
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:GetContentExtent"); 
            Debug.Indent();
            ActiveXInstance.GetExtent(NativeMethods.DVASPECT_CONTENT, pSizel); 
            Debug.Unindent();
        }

        ///  
        /// 
        ///  
        ///  
        int UnsafeNativeMethods.IViewObject.Draw(int dwDrawAspect, int lindex, IntPtr pvAspect, NativeMethods.tagDVTARGETDEVICE ptd,
                                            IntPtr hdcTargetDev, IntPtr hdcDraw, NativeMethods.COMRECT lprcBounds, NativeMethods.COMRECT lprcWBounds, 
                                            IntPtr pfnContinue, int dwContinue) {
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:Draw");

 
            Debug.Indent();
            try { 
                ActiveXInstance.Draw(dwDrawAspect, lindex, pvAspect, ptd, hdcTargetDev, 
                                 hdcDraw, lprcBounds, lprcWBounds, pfnContinue, dwContinue);
 
            }
            catch(ExternalException ex) {
                return ex.ErrorCode;
            } 
            finally {
                Debug.Unindent(); 
            } 
            return NativeMethods.S_OK;
        } 

        /// 
        /// 
        ///  
        /// 
        int UnsafeNativeMethods.IViewObject.GetColorSet(int dwDrawAspect, int lindex, IntPtr pvAspect, NativeMethods.tagDVTARGETDEVICE ptd, 
                                                   IntPtr hicTargetDev, NativeMethods.tagLOGPALETTE ppColorSet) { 

            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:GetColorSet"); 

            // GDI+ doesn't do palettes.
            //
            return NativeMethods.E_NOTIMPL; 
        }
 
        ///  
        /// 
        ///  
        /// 
        int UnsafeNativeMethods.IViewObject.Freeze(int dwDrawAspect, int lindex, IntPtr pvAspect, IntPtr pdwFreeze) {
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:Freezes");
            return NativeMethods.E_NOTIMPL; 
        }
 
        ///  
        /// 
        ///  
        /// 
        int UnsafeNativeMethods.IViewObject.Unfreeze(int dwFreeze) {
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:Unfreeze");
            return NativeMethods.E_NOTIMPL; 
        }
 
        ///  
        /// 
        ///  
        /// 
        void UnsafeNativeMethods.IViewObject.SetAdvise(int aspects, int advf, IAdviseSink pAdvSink) {
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:SetAdvise");
            ActiveXInstance.SetAdvise(aspects, advf, pAdvSink); 
        }
 
        ///  
        /// 
        ///  
        /// 
        void UnsafeNativeMethods.IViewObject.GetAdvise(int[] paspects, int[] padvf, IAdviseSink[] pAdvSink) {
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:GetAdvise");
            ActiveXInstance.GetAdvise(paspects, padvf, pAdvSink); 
        }
 
        ///  
        /// 
        ///  
        /// 
        void UnsafeNativeMethods.IViewObject2.Draw(int dwDrawAspect, int lindex, IntPtr pvAspect, NativeMethods.tagDVTARGETDEVICE ptd,
                                             IntPtr hdcTargetDev, IntPtr hdcDraw, NativeMethods.COMRECT lprcBounds, NativeMethods.COMRECT lprcWBounds,
                                             IntPtr pfnContinue, int dwContinue) { 
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:Draw");
            Debug.Indent(); 
            ActiveXInstance.Draw(dwDrawAspect, lindex, pvAspect, ptd, hdcTargetDev, 
                                 hdcDraw, lprcBounds, lprcWBounds, pfnContinue, dwContinue);
            Debug.Unindent(); 
        }

        /// 
        ///  
        /// 
        ///  
        int UnsafeNativeMethods.IViewObject2.GetColorSet(int dwDrawAspect, int lindex, IntPtr pvAspect, NativeMethods.tagDVTARGETDEVICE ptd, 
                                                    IntPtr hicTargetDev, NativeMethods.tagLOGPALETTE ppColorSet) {
 
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:GetColorSet");

            // GDI+ doesn't do palettes.
            // 
            return NativeMethods.E_NOTIMPL;
        } 
 
        /// 
        ///  
        /// 
        /// 
        int UnsafeNativeMethods.IViewObject2.Freeze(int dwDrawAspect, int lindex, IntPtr pvAspect, IntPtr pdwFreeze) {
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:Freezes"); 
            return NativeMethods.E_NOTIMPL;
        } 
 
        /// 
        ///  
        /// 
        /// 
        int UnsafeNativeMethods.IViewObject2.Unfreeze(int dwFreeze) {
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:Unfreeze"); 
            return NativeMethods.E_NOTIMPL;
        } 
 
        /// 
        ///  
        /// 
        /// 
        void UnsafeNativeMethods.IViewObject2.SetAdvise(int aspects, int advf, IAdviseSink pAdvSink) {
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:SetAdvise"); 
            ActiveXInstance.SetAdvise(aspects, advf, pAdvSink);
        } 
 
        /// 
        ///  
        /// 
        /// 
        void UnsafeNativeMethods.IViewObject2.GetAdvise(int[] paspects, int[] padvf, IAdviseSink[] pAdvSink) {
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:GetAdvise"); 
            ActiveXInstance.GetAdvise(paspects, padvf, pAdvSink);
        } 
 
        /// 
        ///  
        /// 
        /// 
        void UnsafeNativeMethods.IViewObject2.GetExtent(int dwDrawAspect, int lindex, NativeMethods.tagDVTARGETDEVICE ptd, NativeMethods.tagSIZEL lpsizel) {
            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:GetExtent (IViewObject2)"); 
            // we already have an implementation of this [from IOleObject]
            // 
            ((UnsafeNativeMethods.IOleObject)this).GetExtent(dwDrawAspect, lpsizel); 
        }
 
        /// 
        ///      This class holds all of the state data for an ActiveX control and
        ///      supplies the implementation for many of the non-trivial methods.
        ///  
        /// 
        private class ActiveXImpl : MarshalByRefObject, IWindowTarget { 
            // SECUNDONE : This call is private and is only used to expose a WinForm control as 
            //           : an ActiveX control. This class needs more review.
            // 

            private static readonly int     hiMetricPerInch = 2540;
            private static readonly int     viewAdviseOnlyOnce = BitVector32.CreateMask();
            private static readonly int     viewAdvisePrimeFirst = BitVector32.CreateMask(viewAdviseOnlyOnce); 
            private static readonly int     eventsFrozen = BitVector32.CreateMask(viewAdvisePrimeFirst);
            private static readonly int     changingExtents = BitVector32.CreateMask(eventsFrozen); 
            private static readonly int     saving = BitVector32.CreateMask(changingExtents); 
            private static readonly int     isDirty = BitVector32.CreateMask(saving);
            private static readonly int     inPlaceActive = BitVector32.CreateMask(isDirty); 
            private static readonly int     inPlaceVisible = BitVector32.CreateMask(inPlaceActive);
            private static readonly int     uiActive = BitVector32.CreateMask(inPlaceVisible);
            private static readonly int     uiDead = BitVector32.CreateMask(uiActive);
            private static readonly int     adjustingRect = BitVector32.CreateMask(uiDead); 

            private static Point            logPixels = Point.Empty; 
            private static NativeMethods.tagOLEVERB[]     axVerbs; 

            private static int              globalActiveXCount = 0; 
            private static bool             checkedIE;
            private static bool             isIE;

 
            #if ACTIVEX_SOURCING
 
            // 
            // This has been cut from the product.
            // 

            private static ActiveXPropPage  propPage;

            #endif 

            private Control                 control; 
            private IWindowTarget           controlWindowTarget; 
            private IntPtr                  clipRegion;
            private UnsafeNativeMethods.IOleClientSite          clientSite; 
            private UnsafeNativeMethods.IOleInPlaceUIWindow     inPlaceUiWindow;
            private UnsafeNativeMethods.IOleInPlaceFrame        inPlaceFrame;
            private ArrayList               adviseList;
            private IAdviseSink             viewAdviseSink; 
            private BitVector32             activeXState;
            private AmbientProperty[]       ambientProperties; 
            private IntPtr                  hwndParent; 
            private IntPtr                  accelTable;
            private short                   accelCount = -1; 
            private NativeMethods.COMRECT   adjustRect; // temporary rect used during OnPosRectChange && SetObjectRects

            /// 
            ///  
            ///      Creates a new ActiveXImpl.
            ///  
            internal ActiveXImpl(Control control) { 
                this.control = control;
 
                // We replace the control's window target with our own.  We
                // do this so we can handle the UI Dead ambient property.
                //
                controlWindowTarget = control.WindowTarget; 
                control.WindowTarget = this;
 
                adviseList = new ArrayList(); 
                activeXState = new BitVector32();
                ambientProperties = new AmbientProperty[] { 
                    new AmbientProperty("Font", NativeMethods.ActiveX.DISPID_AMBIENT_FONT),
                    new AmbientProperty("BackColor", NativeMethods.ActiveX.DISPID_AMBIENT_BACKCOLOR),
                    new AmbientProperty("ForeColor", NativeMethods.ActiveX.DISPID_AMBIENT_FORECOLOR)
                }; 
            }
 
            ///  
            /// 
            ///      Retrieves the ambient back color for the control. 
            /// 
            [Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced), DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
            internal Color AmbientBackColor {
                get { 
                    AmbientProperty prop = LookupAmbient(NativeMethods.ActiveX.DISPID_AMBIENT_BACKCOLOR);
 
                    if (prop.Empty) { 
                        Object obj = null;
                        if (GetAmbientProperty(NativeMethods.ActiveX.DISPID_AMBIENT_BACKCOLOR, ref obj)) { 
                            if (obj != null) {
                                try {
                                    Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "Object color type=" + obj.GetType().FullName);
                                    prop.Value = ColorTranslator.FromOle(Convert.ToInt32(obj, CultureInfo.InvariantCulture)); 
                                }
                                catch (Exception e) { 
                                    Debug.Fail("Failed to massage ambient back color to a Color", e.ToString()); 

                                    if (ClientUtils.IsSecurityOrCriticalException(e)) { 
                                        throw;
                                    }
                                }
                            } 
                        }
                    } 
 
                    if (prop.Value == null) {
                        return Color.Empty; 
                    }
                    else {
                        return(Color)prop.Value;
                    } 
                }
            } 
 
            /// 
            ///      Retrieves the ambient font for the control. 
            /// 
            [Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced), DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
            internal Font AmbientFont {
                [ResourceExposure(ResourceScope.None)] 
                [ResourceConsumption(ResourceScope.Process, ResourceScope.Process)]
                get { 
                    AmbientProperty prop = LookupAmbient(NativeMethods.ActiveX.DISPID_AMBIENT_FONT); 

                    if (prop.Empty) { 
                        Object obj = null;
                        if (GetAmbientProperty(NativeMethods.ActiveX.DISPID_AMBIENT_FONT, ref obj)) {
                            try {
                                Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "Object font type=" + obj.GetType().FullName); 
                                Debug.Assert(obj != null, "GetAmbientProperty failed");
                                IntPtr hfont = IntPtr.Zero; 
 

                                UnsafeNativeMethods.IFont ifont = (UnsafeNativeMethods.IFont)obj; 
                                IntSecurity.ObjectFromWin32Handle.Assert();
                                Font font = null;
                                try {
                                    hfont = ifont.GetHFont(); 
                                    font = Font.FromHfont(hfont);
                                } 
                                finally { 
                                    CodeAccessPermission.RevertAssert();
                                } 
                                prop.Value = font;
                            }
                            catch (Exception e) {
                                if (ClientUtils.IsSecurityOrCriticalException(e)) { 
                                    throw;
                                } 
 
                                // Do NULL, so we just defer to the default font
                                prop.Value = null; 
                            }
                        }
                    }
 
                    return(Font)prop.Value;
                } 
            } 

            ///  
            ///      Retrieves the ambient back color for the control.
            /// 
            [Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced), DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
            internal Color AmbientForeColor { 
                get {
                    AmbientProperty prop = LookupAmbient(NativeMethods.ActiveX.DISPID_AMBIENT_FORECOLOR); 
 
                    if (prop.Empty) {
                        Object obj = null; 
                        if (GetAmbientProperty(NativeMethods.ActiveX.DISPID_AMBIENT_FORECOLOR, ref obj)) {
                            if (obj != null) {
                                try {
                                    Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "Object color type=" + obj.GetType().FullName); 
                                    prop.Value = ColorTranslator.FromOle(Convert.ToInt32(obj, CultureInfo.InvariantCulture));
                                } 
                                catch (Exception e) { 
                                    Debug.Fail("Failed to massage ambient fore color to a Color", e.ToString());
 
                                    if (ClientUtils.IsSecurityOrCriticalException(e)) {
                                        throw;
                                    }
                                } 
                            }
                        } 
                    } 

                    if (prop.Value == null) { 
                        return Color.Empty;
                    }
                    else {
                        return(Color)prop.Value; 
                    }
                } 
            } 

            ///  
            /// 
            ///      Determines if events should be frozen.
            /// 
            [Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced), DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)] 
            internal bool EventsFrozen {
                get { 
                    return activeXState[eventsFrozen]; 
                }
                set { 
                    activeXState[eventsFrozen] = value;
                }
            }
 
            /// 
            ///     Provides access to the parent window handle 
            ///     when we are UI active 
            /// 
            internal IntPtr HWNDParent { 
                get {
                    return hwndParent;
                }
            } 

            ///  
            ///     Returns true if this app domain is running inside of IE.  The 
            ///     control must be sited for this to succeed (it will assert and
            ///     return false if the control is not sited). 
            /// 
            internal bool IsIE {
                [SecurityPermission(SecurityAction.Assert, Flags=SecurityPermissionFlag.UnmanagedCode)]
                get { 
                    if (!checkedIE) {
                        if (clientSite == null) { 
                            Debug.Fail("Do not reference IsIE property unless control is sited."); 
                            return false;
                        } 

                        // First, is this a managed EXE?  If so, it will correctly shut down
                        // the runtime.
                        if (Assembly.GetEntryAssembly() == null) { 
                            // Now check for IHTMLDocument2
                            UnsafeNativeMethods.IOleContainer container; 
 
                            if (NativeMethods.Succeeded(clientSite.GetContainer(out container)) && container is NativeMethods.IHTMLDocument) {
                                isIE = true; 
                                Debug.WriteLineIf(CompModSwitches.ActiveX.TraceVerbose, "AxSource:IsIE running under IE");
                            }

                            if (container != null && UnsafeNativeMethods.IsComObject(container)) { 
                                UnsafeNativeMethods.ReleaseComObject(container);
                            } 
                        } 

                        checkedIE = true; 
                    }

                    return isIE;
                } 
            }
 
            ///  
            ///      Retrieves the number of logical pixels per inch on the
            ///      primary monitor. 
            /// 
            private Point LogPixels {
                get {
                    if (logPixels.IsEmpty) { 
                        logPixels = new Point();
                        IntPtr dc = UnsafeNativeMethods.GetDC(NativeMethods.NullHandleRef); 
                        logPixels.X = UnsafeNativeMethods.GetDeviceCaps(new HandleRef(null, dc), NativeMethods.LOGPIXELSX); 
                        logPixels.Y = UnsafeNativeMethods.GetDeviceCaps(new HandleRef(null, dc), NativeMethods.LOGPIXELSY);
                        UnsafeNativeMethods.ReleaseDC(NativeMethods.NullHandleRef, new HandleRef(null, dc)); 
                    }
                    return logPixels;
                }
            } 

            ///  
            ///  
            ///      Implements IOleObject::Advise
            ///  
            internal int Advise(IAdviseSink pAdvSink) {
                adviseList.Add(pAdvSink);
                return adviseList.Count;
            } 

            ///  
            ///  
            ///      Implements IOleObject::Close
            ///  
            internal void Close(int dwSaveOption) {
                if (activeXState[inPlaceActive]) {
                    InPlaceDeactivate();
                } 

                if ((dwSaveOption == NativeMethods.OLECLOSE_SAVEIFDIRTY || 
                     dwSaveOption == NativeMethods.OLECLOSE_PROMPTSAVE) && 
                    activeXState[isDirty]) {
 
                    if (clientSite != null) {
                        clientSite.SaveObject();
                    }
                    SendOnSave(); 
                }
            } 
 
            /// 
            ///  
            ///      Implements IOleObject::DoVerb
            /// 
            internal void DoVerb(int iVerb, IntPtr lpmsg, UnsafeNativeMethods.IOleClientSite pActiveSite, int lindex, IntPtr hwndParent, NativeMethods.COMRECT lprcPosRect) {
                Debug.WriteLineIf(CompModSwitches.ActiveX.TraceVerbose, "AxSource:ActiveXImpl:DoVerb(" + iVerb + ")"); 
                switch (iVerb) {
                    case NativeMethods.OLEIVERB_SHOW: 
                    case NativeMethods.OLEIVERB_INPLACEACTIVATE: 
                    case NativeMethods.OLEIVERB_UIACTIVATE:
                    case NativeMethods.OLEIVERB_PRIMARY: 
                        Debug.WriteLineIf(CompModSwitches.ActiveX.TraceVerbose, "DoVerb:Show, InPlaceActivate, UIActivate");
                        InPlaceActivate(iVerb);

                        // Now that we're active, send the lpmsg to the control if it 
                        // is valid.
                        // 
                        if (lpmsg != IntPtr.Zero) { 
                            NativeMethods.MSG msg = (NativeMethods.MSG)UnsafeNativeMethods.PtrToStructure(lpmsg, typeof(NativeMethods.MSG));
                            Control target = control; 

                            if (msg.hwnd != control.Handle && msg.message >= NativeMethods.WM_MOUSEFIRST && msg.message <= NativeMethods.WM_MOUSELAST) {

                                // Must translate message coordniates over to our HWND.  We first try 
                                //
                                IntPtr hwndMap = msg.hwnd == IntPtr.Zero ? hwndParent : msg.hwnd; 
                                NativeMethods.POINT pt = new NativeMethods.POINT(); 
                                pt.x = NativeMethods.Util.LOWORD(msg.lParam);
                                pt.y = NativeMethods.Util.HIWORD(msg.lParam); 
                                UnsafeNativeMethods.MapWindowPoints(new HandleRef(null, hwndMap), new HandleRef(control, control.Handle), pt, 1);

                                // check to see if this message should really go to a child
                                //  control, and if so, map the point into that child's window 
                                //  coordinates
                                // 
                                Control realTarget = target.GetChildAtPoint(new Point(pt.x, pt.y)); 
                                if (realTarget != null && realTarget != target) {
                                    UnsafeNativeMethods.MapWindowPoints(new HandleRef(target, target.Handle), new HandleRef(realTarget, realTarget.Handle), pt, 1); 
                                    target = realTarget;
                                }

                                msg.lParam = NativeMethods.Util.MAKELPARAM(pt.x, pt.y); 
                            }
 
#if DEBUG 
                            if (CompModSwitches.ActiveX.TraceVerbose) {
                                Message m = Message.Create(msg.hwnd, msg.message, msg.wParam, msg.lParam); 
                                Debug.WriteLine("Valid message pointer passed, sending to control: " + m.ToString());
                            }
#endif // DEBUG
 
                            if (msg.message == NativeMethods.WM_KEYDOWN && msg.wParam == (IntPtr)NativeMethods.VK_TAB) {
                                target.SelectNextControl(null, Control.ModifierKeys != Keys.Shift, true, true, true); 
                            } 
                            else {
                                target.SendMessage(msg.message, msg.wParam, msg.lParam); 
                            }
                        }
                        break;
 
                        // These affect our visibility
                        // 
                    case NativeMethods.OLEIVERB_HIDE: 
                        Debug.WriteLineIf(CompModSwitches.ActiveX.TraceVerbose, "DoVerb:Hide");
                        UIDeactivate(); 
                        InPlaceDeactivate();
                        if (activeXState[inPlaceVisible]) {
                            SetInPlaceVisible(false);
                        } 
                        break;
 
                    #if ACTIVEX_SOURCING 

                    // 
                    // This has been cut from the product.
                    //

                        // Show our property pages 
                        //
                    case NativeMethods.OLEIVERB_PROPERTIES: 
                        Debug.WriteLineIf(CompModSwitches.ActiveX.TraceVerbose, "DoVerb:Primary, Properties"); 
                        ShowProperties();
                        break; 

                    #endif

                        // All other verbs are notimpl. 
                        //
                    default: 
                        Debug.WriteLineIf(CompModSwitches.ActiveX.TraceVerbose, "DoVerb:Other"); 
                        ThrowHr(NativeMethods.E_NOTIMPL);
                        break; 
                }
            }

            ///  
            /// 
            ///      Implements IViewObject2::Draw. 
            ///  
            internal void Draw(int dwDrawAspect, int lindex, IntPtr pvAspect, NativeMethods.tagDVTARGETDEVICE ptd,
                             IntPtr hdcTargetDev, IntPtr hdcDraw, NativeMethods.COMRECT prcBounds, NativeMethods.COMRECT lprcWBounds, 
                             IntPtr pfnContinue, int dwContinue) {

                // support the aspects required for multi-pass drawing
                // 
                switch (dwDrawAspect) {
                    case NativeMethods.DVASPECT_CONTENT: 
                    case NativeMethods.DVASPECT_OPAQUE: 
                    case NativeMethods.DVASPECT_TRANSPARENT:
                        break; 
                    default:
                        ThrowHr(NativeMethods.DV_E_DVASPECT);
                        break;
                } 

                // We can paint to an enhanced metafile, but not all GDI / GDI+ is 
                // supported on classic metafiles.  We throw VIEW_E_DRAW in the hope that 
                // the caller figures it out and sends us a different DC.
                // 
                int hdcType = UnsafeNativeMethods.GetObjectType(new HandleRef(null, hdcDraw));
                if (hdcType == NativeMethods.OBJ_METADC) {
                    ThrowHr(NativeMethods.VIEW_E_DRAW);
                } 

                NativeMethods.RECT rc; 
                NativeMethods.POINT pVp = new NativeMethods.POINT(); 
                NativeMethods.POINT pW = new NativeMethods.POINT();
                NativeMethods.SIZE  sWindowExt = new NativeMethods.SIZE(); 
                NativeMethods.SIZE  sViewportExt = new NativeMethods.SIZE();
                int   iMode = NativeMethods.MM_TEXT;

                if (!control.IsHandleCreated) { 
                    control.CreateHandle();
                } 
 
                // if they didn't give us a rectangle, just copy over ours
                // 
                if (prcBounds != null) {
                    rc = new NativeMethods.RECT(prcBounds.left, prcBounds.top, prcBounds.right, prcBounds.bottom);

                    // To draw to a given rect, we scale the DC in such a way as to 
                    // make the values it takes match our own happy MM_TEXT.  Then,
                    // we back-convert prcBounds so that we convert it to this coordinate 
                    // system.  This puts us in the most similar coordinates as we currently 
                    // use.
                    // 
                    SafeNativeMethods.LPtoDP(new HandleRef(null, hdcDraw), ref rc, 2);

                    iMode = SafeNativeMethods.SetMapMode(new HandleRef(null, hdcDraw), NativeMethods.MM_ANISOTROPIC);
                    SafeNativeMethods.SetWindowOrgEx(new HandleRef(null, hdcDraw), 0, 0, pW); 
                    SafeNativeMethods.SetWindowExtEx(new HandleRef(null, hdcDraw), control.Width, control.Height, sWindowExt);
                    SafeNativeMethods.SetViewportOrgEx(new HandleRef(null, hdcDraw), rc.left, rc.top, pVp); 
                    SafeNativeMethods.SetViewportExtEx(new HandleRef(null, hdcDraw), rc.right - rc.left, rc.bottom - rc.top, sViewportExt); 
                }
 
                // Now do the actual drawing.  We must ask all of our children to draw as well.
                try {
                    IntPtr flags = (IntPtr)(NativeMethods.PRF_CHILDREN
                                    | NativeMethods.PRF_CLIENT 
                                    | NativeMethods.PRF_ERASEBKGND
                                    | NativeMethods.PRF_NONCLIENT); 
                                  //| NativeMethods.PRF_CHECKVISIBLE 
                                  //| NativeMethods.PRF_OWNED));
 
                    if(hdcType != NativeMethods.OBJ_ENHMETADC) {
                        control.SendMessage(NativeMethods.WM_PRINT, hdcDraw, flags);
                    } else {
                        control.PrintToMetaFile(new HandleRef(null, hdcDraw), flags); 
                    }
                } 
                finally { 
                    // And clean up the DC
                    // 
                    if (prcBounds != null) {
                        SafeNativeMethods.SetWindowOrgEx(new HandleRef(null, hdcDraw), pW.x, pW.y, null);
                        SafeNativeMethods.SetWindowExtEx(new HandleRef(null, hdcDraw), sWindowExt.cx, sWindowExt.cy, null);
                        SafeNativeMethods.SetViewportOrgEx(new HandleRef(null, hdcDraw), pVp.x, pVp.y, null); 
                        SafeNativeMethods.SetViewportExtEx(new HandleRef(null, hdcDraw), sViewportExt.cx, sViewportExt.cy, null);
                        SafeNativeMethods.SetMapMode(new HandleRef(null, hdcDraw), iMode); 
                    } 
                }
            } 

            /// 
            /// 
            ///     Returns a new verb enumerator. 
            /// 
            internal static int EnumVerbs(out UnsafeNativeMethods.IEnumOLEVERB e) { 
                if (axVerbs == null) { 
                    NativeMethods.tagOLEVERB verbShow             = new NativeMethods.tagOLEVERB();
                    NativeMethods.tagOLEVERB verbInplaceActivate  = new NativeMethods.tagOLEVERB(); 
                    NativeMethods.tagOLEVERB verbUIActivate       = new NativeMethods.tagOLEVERB();
                    NativeMethods.tagOLEVERB verbHide             = new NativeMethods.tagOLEVERB();
                    NativeMethods.tagOLEVERB verbPrimary          = new NativeMethods.tagOLEVERB();
                    NativeMethods.tagOLEVERB verbProperties       = new NativeMethods.tagOLEVERB(); 

                    verbShow.lVerb = NativeMethods.OLEIVERB_SHOW; 
                    verbInplaceActivate.lVerb = NativeMethods.OLEIVERB_INPLACEACTIVATE; 
                    verbUIActivate.lVerb = NativeMethods.OLEIVERB_UIACTIVATE;
                    verbHide.lVerb = NativeMethods.OLEIVERB_HIDE; 
                    verbPrimary.lVerb = NativeMethods.OLEIVERB_PRIMARY;
                    verbProperties.lVerb = NativeMethods.OLEIVERB_PROPERTIES;
                    verbProperties.lpszVerbName = SR.GetString(SR.AXProperties);
                    verbProperties.grfAttribs = NativeMethods.ActiveX.OLEVERBATTRIB_ONCONTAINERMENU; 

                    axVerbs = new NativeMethods.tagOLEVERB[] { 
                        verbShow, 
                        verbInplaceActivate,
                        verbUIActivate, 
                        verbHide,
                        verbPrimary
                    #if ACTIVEX_SOURCING
                        ,verbProperties 
                    #endif
                    }; 
                } 

 
                e = new ActiveXVerbEnum(axVerbs);
                return NativeMethods.S_OK;
            }
 
            /// 
            ///     Converts the given string to a byte array. 
            ///  
            private static byte[] FromBase64WrappedString(string text) {
                if (text.IndexOfAny(new char[] {' ', '\r', '\n'}) != -1) { 
                    StringBuilder sb = new StringBuilder(text.Length);
                    for (int i=0; i
            ///      Implements IViewObject2::GetAdvise.
            ///  
            internal void GetAdvise(int[] paspects, int[] padvf, IAdviseSink[] pAdvSink) {
                // if they want it, give it to them 
                // 
                if (paspects != null) {
                    paspects[0] = NativeMethods.DVASPECT_CONTENT; 
                }

                if (padvf != null) {
                    padvf[0] = 0; 

                    if (activeXState[viewAdviseOnlyOnce]) padvf[0] |= NativeMethods.ADVF_ONLYONCE; 
                    if (activeXState[viewAdvisePrimeFirst]) padvf[0] |= NativeMethods.ADVF_PRIMEFIRST; 
                }
 
                if (pAdvSink != null) {
                    pAdvSink[0] = viewAdviseSink;
                }
            } 

            ///  
            ///      Helper function to retrieve an ambient property.  Returns false if the 
            ///      property wasn't found.
            ///  
            private bool GetAmbientProperty(int dispid, ref Object obj) {
                Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource:GetAmbientProperty");
                Debug.Indent();
 
                if (clientSite is UnsafeNativeMethods.IDispatch) {
                    Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "clientSite implements IDispatch"); 
 
                    UnsafeNativeMethods.IDispatch disp = (UnsafeNativeMethods.IDispatch)clientSite;
                    Object[] pvt = new Object[1]; 
                    Guid g = Guid.Empty;
                    int hr = NativeMethods.E_FAIL;

                    IntSecurity.UnmanagedCode.Assert(); 
                    try {
                        hr = disp.Invoke(dispid, ref g, NativeMethods.LOCALE_USER_DEFAULT, 
                                         NativeMethods.DISPATCH_PROPERTYGET, new NativeMethods.tagDISPPARAMS(), 
                                         pvt, null, null);
                    } 
                    finally {
                        CodeAccessPermission.RevertAssert();
                    }
                    if (NativeMethods.Succeeded(hr)) { 
                        Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "IDispatch::Invoke succeeded. VT=" + pvt[0].GetType().FullName);
                        obj = pvt[0]; 
                        Debug.Unindent(); 
                        return true;
                    } 
                    else {
                        Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "IDispatch::Invoke failed. HR: 0x" + String.Format(CultureInfo.CurrentCulture, "{0:X}", hr));
                    }
                } 

                Debug.Unindent(); 
                return false; 
            }
 
            /// 
            ///      Implements IOleObject::GetClientSite.
            /// 
            internal UnsafeNativeMethods.IOleClientSite GetClientSite() { 
                return clientSite;
            } 
 
            /// 
            ///  
            /// 
            /// 
            [SecurityPermission(SecurityAction.Assert, Flags=SecurityPermissionFlag.UnmanagedCode)]
            internal int GetControlInfo(NativeMethods.tagCONTROLINFO pCI) { 
                if (accelCount == -1) {
                    ArrayList mnemonicList = new ArrayList(); 
                    GetMnemonicList(control, mnemonicList); 

                    accelCount = (short)mnemonicList.Count; 

                    if (accelCount > 0) {
                        int accelSize = UnsafeNativeMethods.SizeOf(typeof(NativeMethods.ACCEL));
 
                        // In the worst case we may have two accelerators per mnemonic:  one lower case and
                        // one upper case, hence the * 2 below. 
                        // 
                        IntPtr accelBlob = Marshal.AllocHGlobal(accelSize * accelCount * 2);
 
                        try {
                            NativeMethods.ACCEL accel = new NativeMethods.ACCEL();
                            accel.cmd = 0;
 
                            Debug.Indent();
 
                            accelCount = 0; 

                            foreach(char ch in mnemonicList) { 
                                IntPtr structAddr = (IntPtr)((long)accelBlob + accelCount * accelSize);

                                Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "Mnemonic: " + ch.ToString());
 
                                if (ch >= 'A' && ch <= 'Z') {
 
                                    // Lower case letter 
                                    //
                                    accel.fVirt = NativeMethods.FALT | NativeMethods.FVIRTKEY; 
                                    accel.key = (short)(UnsafeNativeMethods.VkKeyScan(ch) & 0x00FF);
                                    Marshal.StructureToPtr(accel, structAddr, false);

                                    // Upper case letter 
                                    //
                                    accelCount++; 
                                    structAddr = (IntPtr)((long)structAddr + accelSize); 
                                    accel.fVirt = NativeMethods.FALT | NativeMethods.FVIRTKEY | NativeMethods.FSHIFT;
                                    Marshal.StructureToPtr(accel, structAddr, false); 
                                }
                                else {
                                    // Some non-printable character.
                                    // 
                                    accel.fVirt = NativeMethods.FALT | NativeMethods.FVIRTKEY;
                                    short scan = (short)(UnsafeNativeMethods.VkKeyScan(ch)); 
                                    if ((scan & 0x0100) != 0) { 
                                        accel.fVirt |= NativeMethods.FSHIFT;
                                    } 
                                    accel.key = (short)(scan & 0x00FF);
                                    Marshal.StructureToPtr(accel, structAddr, false);
                                }
 
                                accel.cmd++;
                                accelCount++; 
                            } 

                            Debug.Unindent(); 

                            // Now create an accelerator table and then free our memory.
                            //
 
 				// DevDiv Bugs 170945
	                    if (accelTable != IntPtr.Zero) { 
	                        UnsafeNativeMethods.DestroyAcceleratorTable(new HandleRef(this, accelTable)); 
				   accelTable = IntPtr.Zero;
 	                    	} 

                            accelTable = UnsafeNativeMethods.CreateAcceleratorTable(new HandleRef(null, accelBlob), accelCount);
                        }
                        finally { 
                            if (accelBlob != IntPtr.Zero) {
                                Marshal.FreeHGlobal(accelBlob); 
                            } 
                        }
                    } 
                }

                pCI.cAccel = accelCount;
                pCI.hAccel = accelTable; 
                return NativeMethods.S_OK;
            } 
 
            /// 
            ///      Implements IOleObject::GetExtent. 
            /// 
            internal void GetExtent(int dwDrawAspect, NativeMethods.tagSIZEL pSizel) {
                if ((dwDrawAspect & NativeMethods.DVASPECT_CONTENT) != 0) {
                    Size size = control.Size; 

                    Point pt = PixelToHiMetric(size.Width, size.Height); 
                    pSizel.cx = pt.X; 
                    pSizel.cy = pt.Y;
                } 
                else {
                    ThrowHr(NativeMethods.DV_E_DVASPECT);
                }
            } 

            ///  
            ///     Searches the control hierarchy of the given control and adds 
            ///     the mnemonics for each control to mnemonicList.  Each mnemonic
            ///     is added as a char to the list. 
            /// 
            private void GetMnemonicList(Control control, ArrayList mnemonicList) {
                // Get the mnemonic for our control
                // 
                char mnemonic = WindowsFormsUtils.GetMnemonic(control.Text, true);
                if (mnemonic != 0) { 
                    mnemonicList.Add(mnemonic); 
                }
 
                // And recurse for our children.
                //
                foreach(Control c in control.Controls) {
                    if (c != null) GetMnemonicList(c, mnemonicList); 
                }
            } 
 
            /// 
            ///     Name to use for a stream: use the control's type name (max 31 chars, use the end chars 
            ///     if it's longer than that)
            /// 
            private string GetStreamName()
            { 
                string streamName = control.GetType().FullName;
                int len = streamName.Length; 
                if (len > 31) 
                { // The max allowed length of the stream name is 31.
                    streamName = streamName.Substring(len - 31); 
                }
                return streamName;
            }
 
            /// 
            ///      Implements IOleWindow::GetWindow 
            ///  
            internal int GetWindow(out IntPtr hwnd) {
                if (!activeXState[inPlaceActive]) { 
                    hwnd = IntPtr.Zero;
                    return NativeMethods.E_FAIL;
                }
                hwnd = control.Handle; 
                return NativeMethods.S_OK;
            } 
 
            /// 
            ///      Converts coordinates in HiMetric to pixels.  Used for ActiveX sourcing. 
            /// 
            /// 
            private Point HiMetricToPixel(int x, int y) {
                Point pt = new Point(); 
                pt.X = (LogPixels.X * x + hiMetricPerInch / 2) / hiMetricPerInch;
                pt.Y = (LogPixels.Y * y + hiMetricPerInch / 2) / hiMetricPerInch; 
                return pt; 
            }
 
            /// 
            /// 
            ///      In place activates this Object.
            ///  
            [SecurityPermission(SecurityAction.Assert, Flags = SecurityPermissionFlag.UnmanagedCode)]
            internal void InPlaceActivate(int verb) 
            { 
                // If we don't have a client site, then there's not much to do.
                // We also punt if this isn't an in-place site, since we can't 
                // go active then.
                //
                UnsafeNativeMethods.IOleInPlaceSite inPlaceSite = clientSite as UnsafeNativeMethods.IOleInPlaceSite;
                if (inPlaceSite == null) 
                {
                    return; 
                } 

                // If we're not already active, go and do it. 
                //
                if (!activeXState[inPlaceActive]) {
                    Debug.WriteLineIf(CompModSwitches.ActiveX.TraceVerbose, "\tActiveXImpl:InPlaceActivate --> inplaceactive");
 
                    int hr = inPlaceSite.CanInPlaceActivate();
 
                    if (hr != NativeMethods.S_OK) { 
                        if (NativeMethods.Succeeded(hr)) {
                            hr = NativeMethods.E_FAIL; 
                        }
                        ThrowHr(hr);
                    }
 
                    inPlaceSite.OnInPlaceActivate();
 
                    activeXState[inPlaceActive] = true; 
                }
 

                // And if we're not visible, do that too.
                //
                if (!activeXState[inPlaceVisible]) { 
                    Debug.WriteLineIf(CompModSwitches.ActiveX.TraceVerbose, "\tActiveXImpl:InPlaceActivate --> inplacevisible");
                    NativeMethods.tagOIFI inPlaceFrameInfo = new NativeMethods.tagOIFI(); 
                    inPlaceFrameInfo.cb = UnsafeNativeMethods.SizeOf(typeof(NativeMethods.tagOIFI)); 
                    IntPtr hwndParent = IntPtr.Zero;
 
                    // We are entering a secure context here.
                    //
                    hwndParent = inPlaceSite.GetWindow();
 
                    UnsafeNativeMethods.IOleInPlaceFrame pFrame;
                    UnsafeNativeMethods.IOleInPlaceUIWindow pWindow; 
                    NativeMethods.COMRECT posRect = new NativeMethods.COMRECT(); 
                    NativeMethods.COMRECT clipRect = new NativeMethods.COMRECT();
 
                    if (inPlaceUiWindow != null && UnsafeNativeMethods.IsComObject(inPlaceUiWindow)) {
                        UnsafeNativeMethods.ReleaseComObject(inPlaceUiWindow);
                        inPlaceUiWindow = null;
                    } 

                    if (inPlaceFrame != null && UnsafeNativeMethods.IsComObject(inPlaceFrame)) { 
                        UnsafeNativeMethods.ReleaseComObject(inPlaceFrame); 
                        inPlaceFrame = null;
                    } 

                    inPlaceSite.GetWindowContext(out pFrame, out pWindow, posRect, clipRect, inPlaceFrameInfo);

                    SetObjectRects(posRect, clipRect); 

                    inPlaceFrame = pFrame; 
                    inPlaceUiWindow = pWindow; 

                    // We are parenting ourselves 
                    // directly to the host window.  The host must
                    // implement the ambient property
                    // DISPID_AMBIENT_MESSAGEREFLECT.
                    // If it doesn't, that means that the host 
                    // won't reflect messages back to us.
                    // 
                    this.hwndParent = hwndParent; 
                    UnsafeNativeMethods.SetParent(new HandleRef(control, control.Handle), new HandleRef(null, hwndParent));
 
                    // Now create our handle if it hasn't already been done. Note that because
                    // this raises events to the user that it CANNOT be done with a security assertion
                    // in place!
                    // 
                    control.CreateControl();
 
                    clientSite.ShowObject(); 

                    SetInPlaceVisible(true); 
                    Debug.Assert(activeXState[inPlaceVisible], "Failed to set inplacevisible");
                }

                // if we weren't asked to UIActivate, then we're done. 
                //
                if (verb != NativeMethods.OLEIVERB_PRIMARY && verb != NativeMethods.OLEIVERB_UIACTIVATE) { 
                    Debug.WriteLineIf(CompModSwitches.ActiveX.TraceVerbose, "\tActiveXImpl:InPlaceActivate --> not becoming UIActive"); 
                    return;
                } 

                // if we're not already UI active, do sow now.
                //
                if (!activeXState[uiActive]) { 
                    Debug.WriteLineIf(CompModSwitches.ActiveX.TraceVerbose, "\tActiveXImpl:InPlaceActivate --> uiactive");
                    activeXState[uiActive] = true; 
 
                    // inform the container of our intent
                    // 
                    inPlaceSite.OnUIActivate();

                    // take the focus  [which is what UI Activation is all about !]
                    // 
                    if (!control.ContainsFocus) control.FocusInternal();
 
                    // set ourselves up in the host. 
                    //
                    Debug.Assert(inPlaceFrame != null, "Setting us to visible should have created the in place frame"); 
                    inPlaceFrame.SetActiveObject(control, null);
                    if (inPlaceUiWindow != null) {
                        inPlaceUiWindow.SetActiveObject(control, null);
                    } 

                    // we have to explicitly say we don't wany any border space. 
                    // 
                    int hr = inPlaceFrame.SetBorderSpace(null);
                    if (NativeMethods.Failed(hr) && hr != NativeMethods.OLE_E_INVALIDRECT && 
                        hr != NativeMethods.INPLACE_E_NOTOOLSPACE && hr != NativeMethods.E_NOTIMPL) {
                        UnsafeNativeMethods.ThrowExceptionForHR(hr);
                    }
 
                    if (inPlaceUiWindow != null) {
                        hr = inPlaceFrame.SetBorderSpace(null); 
                        if (NativeMethods.Failed(hr) && hr != NativeMethods.OLE_E_INVALIDRECT && 
                            hr != NativeMethods.INPLACE_E_NOTOOLSPACE && hr != NativeMethods.E_NOTIMPL) {
                            UnsafeNativeMethods.ThrowExceptionForHR(hr); 
                        }
                    }
                }
                else { 
                    Debug.WriteLineIf(CompModSwitches.ActiveX.TraceVerbose, "\tActiveXImpl:InPlaceActivate --> already uiactive");
                } 
            } 

            ///  
            /// 
            ///      Implements IOleInPlaceObject::InPlaceDeactivate.
            /// 
            internal void InPlaceDeactivate() { 

                // Only do this if we're already in place active. 
                // 
                if (!activeXState[inPlaceActive]) {
                    return; 
                }

                // Deactivate us if we're UI active
                // 
                if (activeXState[uiActive]) {
                    UIDeactivate(); 
                } 

                // Some containers may call into us to save, and if we're still 
                // active we will try to deactivate and recurse back into the container.
                // So, set the state bits here first.
                //
                activeXState[inPlaceActive] = false; 
                activeXState[inPlaceVisible] = false;
 
                // Notify our site of our deactivation. 
                //
                UnsafeNativeMethods.IOleInPlaceSite oleClientSite = clientSite as UnsafeNativeMethods.IOleInPlaceSite; 
                if (oleClientSite != null) {
                    IntSecurity.UnmanagedCode.Assert();
                    try {
                        oleClientSite.OnInPlaceDeactivate(); 
                    }
                    finally { 
                        CodeAccessPermission.RevertAssert(); 
                    }
                } 

                control.Visible = false;
                hwndParent = IntPtr.Zero;
 
                if (inPlaceUiWindow != null && UnsafeNativeMethods.IsComObject(inPlaceUiWindow)) {
                    UnsafeNativeMethods.ReleaseComObject(inPlaceUiWindow); 
                    inPlaceUiWindow = null; 
                }
 
                if (inPlaceFrame != null && UnsafeNativeMethods.IsComObject(inPlaceFrame)) {
                    UnsafeNativeMethods.ReleaseComObject(inPlaceFrame);
                    inPlaceFrame = null;
                } 
            }
 
            ///  
            ///      Implements IPersistStreamInit::IsDirty.
            ///  
            internal int IsDirty() {
                if (activeXState[isDirty]) {
                    return NativeMethods.S_OK;
                } 
                else {
                    return NativeMethods.S_FALSE; 
                } 
            }
 
            /// 
            ///      Looks at the property to see if it should be loaded / saved as a resource or
            ///      through a type converter.
            ///  
            private bool IsResourceProp(PropertyDescriptor prop) {
                TypeConverter converter = prop.Converter; 
                Type[] convertTypes = new Type[] { 
                    typeof(string),
                    typeof(byte[]) 
                    };

                foreach (Type t in convertTypes) {
                    if (converter.CanConvertTo(t) && converter.CanConvertFrom(t)) { 
                        return false;
                    } 
                } 

                // Finally, if the property can be serialized, it is a resource property. 
                //
                return (prop.GetValue(control) is ISerializable);
            }
 
            /// 
            ///  
            ///      Implements IPersistStorage::Load 
            /// 
            internal void Load(UnsafeNativeMethods.IStorage stg) { 
                UnsafeNativeMethods.IStream stream = null;

                IntSecurity.UnmanagedCode.Assert();
                try { 
                    stream = stg.OpenStream(this.GetStreamName(), IntPtr.Zero, NativeMethods.STGM_READ | NativeMethods.STGM_SHARE_EXCLUSIVE, 0);
                } 
                catch (COMException e) { 
                    if (e.ErrorCode == NativeMethods.STG_E_FILENOTFOUND) {
                        // For backward compatibility: We were earlier using GetType().FullName 
                        // as the stream name in v1. Lets see if a stream by that name exists.
                        stream = stg.OpenStream(GetType().FullName, IntPtr.Zero, NativeMethods.STGM_READ | NativeMethods.STGM_SHARE_EXCLUSIVE, 0);
                    }
                    else { 
                        throw;
                    } 
                } 
                finally {
                    CodeAccessPermission.RevertAssert(); 
                }

                Load(stream);
                stream = null; 
                if (UnsafeNativeMethods.IsComObject(stg)) {
                    UnsafeNativeMethods.ReleaseComObject(stg); 
                } 
            }
 
            /// 
            /// 
            ///      Implements IPersistStreamInit::Load
            ///  
            internal void Load(UnsafeNativeMethods.IStream stream) {
                // We do everything through property bags because we support full fidelity 
                // in them.  So, load through that method. 
                //
                PropertyBagStream bag = new PropertyBagStream(); 
                bag.Read(stream);
                Load(bag, null);

                if (UnsafeNativeMethods.IsComObject(stream)) { 
                    UnsafeNativeMethods.ReleaseComObject(stream);
                } 
            } 

            ///  
            ///      Implements IPersistPropertyBag::Load
            /// 
            internal void Load(UnsafeNativeMethods.IPropertyBag pPropBag, UnsafeNativeMethods.IErrorLog pErrorLog) {
                PropertyDescriptorCollection props = TypeDescriptor.GetProperties(control, 
                    new Attribute[] {DesignerSerializationVisibilityAttribute.Visible});
 
                for (int i = 0; i < props.Count; i++) { 
                    Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "Loading property " + props[i].Name);
 
                    try {
                        object obj = null;
                        int hr = NativeMethods.E_FAIL;
 
                        IntSecurity.UnmanagedCode.Assert();
                        try { 
                            hr = pPropBag.Read(props[i].Name, ref obj, pErrorLog); 
                        }
                        finally { 
                            CodeAccessPermission.RevertAssert();
                        }

                        if (NativeMethods.Succeeded(hr) && obj != null) { 
                            Debug.Indent();
                            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "Property was in bag"); 
 
                            String errorString = null;
                            int errorCode = 0; 

                            try {
                                if (obj.GetType() != typeof(string)) {
                                    Debug.Fail("Expected property " + props[i].Name + " to be stored in IPropertyBag as a string.  Attempting to coerce"); 
                                    obj = Convert.ToString(obj, CultureInfo.InvariantCulture);
                                } 
 
                                // Determine if this is a resource property or was persisted via a type converter.
                                // 
                                if (IsResourceProp(props[i])) {
                                    Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "It's a resource property");

                                    // Resource property.  We encode these as base 64 strings.  To load them, we convert 
                                    // to a binary blob and then de-serialize.
                                    // 
                                    byte[] bytes = Convert.FromBase64String(obj.ToString()); 
                                    MemoryStream stream = new MemoryStream(bytes);
                                    BinaryFormatter formatter = new BinaryFormatter(); 
                                    props[i].SetValue(control, formatter.Deserialize(stream));
                                }
                                else {
                                    Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "It's a standard property"); 

                                    // Not a resource property.  Use TypeConverters to convert the string back to the data type.  We do 
                                    // not check for CanConvertFrom here -- we the conversion fails the type converter will throw, 
                                    // and we will log it into the COM error log.
                                    // 
                                    TypeConverter converter = props[i].Converter;
                                    Debug.Assert(converter != null, "No type converter for property '" + props[i].Name + "' on class " + control.GetType().FullName);

                                    // Check to see if the type converter can convert from a string.  If it can,. 
                                    // use that as it is the best format for IPropertyBag.  Otherwise, check to see
                                    // if it can convert from a byte array.  If it can, get the string, decode it 
                                    // to a byte array, and then set the value. 
                                    //
                                    object value = null; 

                                    if (converter.CanConvertFrom(typeof(string))) {
                                        value = converter.ConvertFromInvariantString(obj.ToString());
                                    } 
                                    else if (converter.CanConvertFrom(typeof(byte[]))) {
                                        string objString = obj.ToString(); 
                                        value = converter.ConvertFrom(null, CultureInfo.InvariantCulture, FromBase64WrappedString(objString)); 
                                    }
                                    Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "Converter returned " + value); 
                                    props[i].SetValue(control, value);
                                }
                            }
                            catch (Exception e) { 
                                errorString = e.ToString();
                                if (e is ExternalException) { 
                                    errorCode = ((ExternalException) e).ErrorCode; 
                                }
                                else { 
                                    errorCode = NativeMethods.E_FAIL;
                                }
                            }
                            if (errorString != null) { 
                                Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "Exception converting property: " + errorString);
                                if (pErrorLog != null) { 
                                    NativeMethods.tagEXCEPINFO err = new NativeMethods.tagEXCEPINFO(); 
                                    err.bstrSource = control.GetType().FullName;
                                    err.bstrDescription = errorString; 
                                    err.scode = errorCode;
                                    pErrorLog.AddError(props[i].Name, err);
                                }
                            } 
                            Debug.Unindent();
                        } 
                    } 
                    catch (Exception ex) {
                        Debug.Fail("Unexpected failure reading property", ex.ToString()); 

                        if (ClientUtils.IsSecurityOrCriticalException(ex)) {
                            throw;
                        } 
                    }
                } 
                if (UnsafeNativeMethods.IsComObject(pPropBag)) { 
                    UnsafeNativeMethods.ReleaseComObject(pPropBag);
                } 
            }

            /// 
            ///      Simple lookup to find the AmbientProperty corresponding to the given 
            ///      dispid.
            ///  
            private AmbientProperty LookupAmbient(int dispid) { 
                for (int i = 0; i < ambientProperties.Length; i++) {
                    if (ambientProperties[i].DispID == dispid) { 
                        return ambientProperties[i];
                    }
                }
                Debug.Fail("No ambient property for dispid " + dispid.ToString(CultureInfo.InvariantCulture)); 
                return ambientProperties[0];
            } 
 
            /// 
            ///      Merges the input region with the current clipping region. 
            ///      The output is always a region that can be fed directly
            ///      to SetWindowRgn.  The region does not have to be destroyed.
            ///      The original region is destroyed if a new region is returned.
            ///  
            [ResourceExposure(ResourceScope.Process)]
            [ResourceConsumption(ResourceScope.Process)] 
            internal IntPtr MergeRegion(IntPtr region) { 
                if (clipRegion == IntPtr.Zero) {
                    return region; 
                }

                if (region == IntPtr.Zero) {
                    return clipRegion; 
                }
 
                try { 
                    //
 
                    IntPtr newRegion = SafeNativeMethods.CreateRectRgn(0, 0, 0, 0);
                    try {
                        SafeNativeMethods.CombineRgn(new HandleRef(null, newRegion), new HandleRef(null, region), new HandleRef(this, clipRegion), NativeMethods.RGN_DIFF);
                        SafeNativeMethods.DeleteObject(new HandleRef(null, region)); 
                    }
                    catch { 
                        SafeNativeMethods.DeleteObject(new HandleRef(null, newRegion)); 
                        throw;
                    } 
                    return newRegion;
                }
                catch (Exception e) {
                    if (ClientUtils.IsSecurityOrCriticalException(e)) { 
                        throw;
                    } 
 
                    // If something goes wrong, use the original region.
                    return region; 
                }
            }

            private void CallParentPropertyChanged(Control control, string propName) { 
                switch (propName) {
                    case "BackColor" : 
                        control.OnParentBackColorChanged(EventArgs.Empty); 
                        break;
 
                    case "BackgroundImage" :
                        control.OnParentBackgroundImageChanged(EventArgs.Empty);
                        break;
 
                    case "BindingContext" :
                        control.OnParentBindingContextChanged(EventArgs.Empty); 
                        break; 

                    case "Enabled" : 
                        control.OnParentEnabledChanged(EventArgs.Empty);
                        break;

                    case "Font" : 
                        control.OnParentFontChanged(EventArgs.Empty);
                        break; 
 
                    case "ForeColor" :
                        control.OnParentForeColorChanged(EventArgs.Empty); 
                        break;

                    case "RightToLeft" :
                        control.OnParentRightToLeftChanged(EventArgs.Empty); 
                        break;
 
                    case "Visible" : 
                        control.OnParentVisibleChanged(EventArgs.Empty);
                        break; 

                    default:
                        Debug.Fail("There is no property change notification for: " + propName + " on Control.");
                        break; 
                }
            } 
 
            /// 
            ///  
            ///      Implements IOleControl::OnAmbientPropertyChanged
            /// 
            internal void OnAmbientPropertyChange(int dispID) {
                if (dispID != NativeMethods.ActiveX.DISPID_UNKNOWN) { 

                    // Look for a specific property that has changed. 
                    // 
                    for (int i = 0; i < ambientProperties.Length; i++) {
                        if (ambientProperties[i].DispID == dispID) { 
                            ambientProperties[i].ResetValue();
                            CallParentPropertyChanged(control, ambientProperties[i].Name);
                            return;
                        } 
                    }
 
                    // Special properties that we care about 
                    //
                    Object obj = new Object(); 

                    switch (dispID) {
                        case NativeMethods.ActiveX.DISPID_AMBIENT_UIDEAD:
                            if (GetAmbientProperty(NativeMethods.ActiveX.DISPID_AMBIENT_UIDEAD, ref obj)) { 
                                activeXState[uiDead] = (bool)obj;
                            } 
                            break; 

                        case NativeMethods.ActiveX.DISPID_AMBIENT_DISPLAYASDEFAULT: 
                            IButtonControl ibuttonControl = control as IButtonControl;
                            if (ibuttonControl != null && GetAmbientProperty(NativeMethods.ActiveX.DISPID_AMBIENT_DISPLAYASDEFAULT, ref obj)) {
                                ibuttonControl.NotifyDefault((bool)obj);
                            } 
                            break;
                    } 
                } 
                else {
                    // Invalidate all properties.  Ideally we should be checking each one, but 
                    // that's pretty expensive too.
                    //
                    for (int i = 0; i < ambientProperties.Length; i++) {
                        ambientProperties[i].ResetValue(); 
                        CallParentPropertyChanged(control, ambientProperties[i].Name);
                    } 
                } 
            }
 
            /// 
            /// 
            ///      Implements IOleInPlaceActiveObject::OnDocWindowActivate.
            ///  
            internal void OnDocWindowActivate(int fActivate) {
                if (activeXState[uiActive] && fActivate != 0 && inPlaceFrame != null) { 
                    // we have to explicitly say we don't wany any border space. 
                    //
                    int hr; 
                    IntSecurity.UnmanagedCode.Assert();
                    try {
                        hr = inPlaceFrame.SetBorderSpace(null);
                    } 
                    finally {
                        CodeAccessPermission.RevertAssert(); 
                    } 
                    if (NativeMethods.Failed(hr) && hr != NativeMethods.INPLACE_E_NOTOOLSPACE && hr != NativeMethods.E_NOTIMPL) {
                        UnsafeNativeMethods.ThrowExceptionForHR(hr); 
                    }
                }
            }
 
            /// 
            ///     Called by Control when it gets the focus. 
            ///  
            internal void OnFocus(bool focus) {
                Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AXSource: SetFocus:  " + focus.ToString()); 
                if (activeXState[inPlaceActive] && clientSite is UnsafeNativeMethods.IOleControlSite) {
                    IntSecurity.UnmanagedCode.Assert();
                    try {
                        ((UnsafeNativeMethods.IOleControlSite)clientSite).OnFocus(focus ? 1 : 0); 
                    }
                    finally { 
                        CodeAccessPermission.RevertAssert(); 
                    }
                } 

                if (focus && activeXState[inPlaceActive] && !activeXState[uiActive]) {
                    InPlaceActivate(NativeMethods.OLEIVERB_UIACTIVATE);
                } 
            }
 
            ///  
            ///      Converts coordinates in pixels to HiMetric.
            ///  
            /// 
            private Point PixelToHiMetric(int x, int y) {
                Point pt = new Point();
                pt.X = (hiMetricPerInch * x + (LogPixels.X >> 1)) / LogPixels.X; 
                pt.Y = (hiMetricPerInch * y + (LogPixels.Y >> 1)) / LogPixels.Y;
                return pt; 
            } 

            ///  
            /// 
            ///     Our implementation of IQuickActivate::QuickActivate
            /// 
            internal void QuickActivate(UnsafeNativeMethods.tagQACONTAINER pQaContainer, UnsafeNativeMethods.tagQACONTROL pQaControl) { 
                // Hookup our ambient colors
                // 
                AmbientProperty prop = LookupAmbient(NativeMethods.ActiveX.DISPID_AMBIENT_BACKCOLOR); 
                prop.Value = ColorTranslator.FromOle(unchecked((int)pQaContainer.colorBack));
 
                prop = LookupAmbient(NativeMethods.ActiveX.DISPID_AMBIENT_FORECOLOR);
                prop.Value = ColorTranslator.FromOle(unchecked((int)pQaContainer.colorFore));

                // And our ambient font 
                //
                if (pQaContainer.pFont != null) { 
 
                    prop = LookupAmbient(NativeMethods.ActiveX.DISPID_AMBIENT_FONT);
 
                    IntSecurity.UnmanagedCode.Assert();
                    try
                    {
                        IntPtr hfont = IntPtr.Zero; 
                        object objfont = pQaContainer.pFont;
                        UnsafeNativeMethods.IFont ifont = (UnsafeNativeMethods.IFont)objfont; 
                        hfont = ifont.GetHFont(); 
                        Font font = Font.FromHfont(hfont);
                        prop.Value = font; 
                    }
                    catch (Exception e) {
                        if (ClientUtils.IsSecurityOrCriticalException(e)) {
                            throw; 
                        }
 
                        // Do NULL, so we just defer to the default font 
                        prop.Value = null;
                    } 
                    finally {
                        CodeAccessPermission.RevertAssert();
                    }
                } 

                // Now use the rest of the goo that we got passed in. 
                // 
                int status;
 
                pQaControl.cbSize = UnsafeNativeMethods.SizeOf(typeof(UnsafeNativeMethods.tagQACONTROL));

                SetClientSite(pQaContainer.pClientSite);
 
                if (pQaContainer.pAdviseSink != null) {
                    SetAdvise(NativeMethods.DVASPECT_CONTENT, 0, (IAdviseSink)pQaContainer.pAdviseSink); 
                } 

                IntSecurity.UnmanagedCode.Assert(); 
                try {
                    ((UnsafeNativeMethods.IOleObject)control).GetMiscStatus(NativeMethods.DVASPECT_CONTENT, out status);
                }
                finally { 
                    CodeAccessPermission.RevertAssert();
                } 
                pQaControl.dwMiscStatus = status; 

                // VSWhidbey 591430. Advise the event sink so VB6 can catch events raised from UserControls. 
                // VB6 expects the control to do this during IQuickActivate, otherwise it will not hook events at runtime.
                // We will do this if all of the following are true:
                //  1. The container (e.g., vb6) has supplied an event sink
                //  2. The control is a UserControl (this is only to limit the scope of the changed behavior) 
                //  3. The UserControl has indicated it wants to expose events to COM via the ComSourceInterfacesAttribute
                // Note that the AdviseHelper handles some non-standard COM interop that is required in order to access 
                // the events on the CLR-supplied CCW (COM-callable Wrapper. 

                if ((pQaContainer.pUnkEventSink != null) && (control is UserControl)) { 
                    // Check if this control exposes events to COM.
                    Type eventInterface = GetDefaultEventsInterface(control.GetType());

                    if (eventInterface != null) { 

                        IntSecurity.UnmanagedCode.Assert(); 
                        try { 
                            // For the default source interface, call IConnectionPoint.Advise with the supplied event sink.
                            // This is easier said than done. See notes in AdviseHelper.AdviseConnectionPoint. 
                            AdviseHelper.AdviseConnectionPoint(control, pQaContainer.pUnkEventSink, eventInterface, out pQaControl.dwEventCookie);
                        }
                        catch (Exception e) {
                            if (ClientUtils.IsSecurityOrCriticalException(e)) { 
                                throw;
                            } 
                        } 
                        finally {
                            CodeAccessPermission.RevertAssert(); 
                        }
                    }
                }
 
                if (pQaContainer.pPropertyNotifySink != null && UnsafeNativeMethods.IsComObject(pQaContainer.pPropertyNotifySink)) {
                    UnsafeNativeMethods.ReleaseComObject(pQaContainer.pPropertyNotifySink); 
                } 

                if (pQaContainer.pUnkEventSink != null && UnsafeNativeMethods.IsComObject(pQaContainer.pUnkEventSink)) { 
                    UnsafeNativeMethods.ReleaseComObject(pQaContainer.pUnkEventSink);
                }
            }
 
            /// 
            ///     Helper class. Calls IConnectionPoint.Advise to hook up a native COM event sink 
            ///     to a manage .NET event interface. 
            ///     The events are exposed to COM by the CLR-supplied COM-callable Wrapper (CCW).
            ///  
            internal static class AdviseHelper {
                /// 
                ///     Get the COM connection point container from the CLR's CCW and advise for the given event id.
                ///  
                public static bool AdviseConnectionPoint(object connectionPoint, object sink, Type eventInterface, out int cookie) {
 
                    // Note that we cannot simply cast the connectionPoint object to 
                    // System.Runtime.InteropServices.ComTypes.IConnectionPointContainer because the .NET
                    // object doesn't implement it directly. When the object is exposed to COM, the CLR 
                    // implements IConnectionPointContainer on the proxy object called the CCW or COM-callable wrapper.
                    // We use the helper class ComConnectionPointContainer to get to the CCW directly
                    // to to call the interface.
                    // It is critical to call Dispose to ensure that the IUnknown is released. 

                    using (ComConnectionPointContainer cpc = new ComConnectionPointContainer(connectionPoint, true)) { 
                        return AdviseConnectionPoint(cpc, sink, eventInterface, out cookie); 
                    }
                } 

                /// 
                ///     Find the COM connection point and call Advise for the given event id.
                ///  
                [SuppressMessage("Microsoft.Reliability", "CA2001:AvoidCallingProblematicMethods", MessageId = "System.Runtime.InteropServices.SafeHandle.DangerousGetHandle")]
                internal static bool AdviseConnectionPoint(ComConnectionPointContainer cpc, object sink, Type eventInterface, out int cookie) { 
 
                    // Note that we cannot simply cast the returned IConnectionPoint to
                    // System.Runtime.InteropServices.ComTypes.IConnectionPoint because the .NET 
                    // object doesn't implement it directly. When the object is exposed to COM, the CLR
                    // implements IConnectionPoint for the proxy object via the CCW or COM-callable wrapper.
                    // We use the helper class ComConnectionPoint to get to the CCW directly to to call the interface.
                    // It is critical to call Dispose to ensure that the IUnknown is released. 

                    using (ComConnectionPoint cp = cpc.FindConnectionPoint(eventInterface)) { 
                        using (SafeIUnknown punkEventsSink = new SafeIUnknown(sink, true)) { 
                            // Finally...we can call IConnectionPoint.Advise to hook up a native COM event sink
                            // to a managed .NET event interface. 
                            return cp.Advise(punkEventsSink.DangerousGetHandle(), out cookie);
                        }
                    }
                } 

                ///  
                ///     Wraps a native IUnknown in a SafeHandle. 
                ///     See similar implementaton in the  class.
                ///  
                internal class SafeIUnknown : SafeHandle {

                    /// 
                    ///     Wrap an incomoing unknown or get the unknown for the CCW (COM-callable wrapper). 
                    /// 
                    public SafeIUnknown(object obj, bool addRefIntPtr) 
                        : this(obj, addRefIntPtr, Guid.Empty) { 
                    }
 
                    /// 
                    ///     Wrap an incomoing unknown or get the unknown for the CCW (COM-callable wrapper).
                    ///     If an iid is supplied, QI for the interface and wrap that unknonwn instead.
                    ///  
                    public SafeIUnknown(object obj, bool addRefIntPtr, Guid iid)
                        : base(IntPtr.Zero, true) { 
 
                        System.Runtime.CompilerServices.RuntimeHelpers.PrepareConstrainedRegions();
                        try { 

                            // Set this.handle in a finally block to ensure the com ptr is set in the SafeHandle
                            // even if the runtime throws a exception (such as ThreadAbortException) during the call.
                            // This ensures that the finalizer will clean up the COM reference. 
                        }
                        finally { 
 
                            // Get a raw IUnknown for this object.
                            // We are responsible for releasing the IUnknown ourselves. 
                            IntPtr unknown;

                            if (obj is IntPtr) {
                                unknown = (IntPtr)obj; 

                                // The incoming IntPtr may already be reference counted or not, depending on 
                                // where it came from. The caller needs to tell us whether to add-ref or not. 
                                if (addRefIntPtr) {
                                    Marshal.AddRef(unknown); 
                                }

                            } else {
                                // GetIUnknownForObject will return a reference-counted object 
                                unknown = Marshal.GetIUnknownForObject(obj);
                            } 
 
                            // Attempt QueryInterface if an iid is specified.
                            if (iid != Guid.Empty) { 
                                IntPtr oldUnknown = unknown;
                                try {
                                    unknown = InternalQueryInterface(unknown, ref iid);
                                } 
                                finally {
                                    // It is critical to release the original unknown if 
                                    // InternalQueryInterface throws out so we don't leak ref counts. 
                                    Marshal.Release(oldUnknown);
                                } 
                            }

                            // Preserve the com ptr in the SafeHandle.
                            this.handle = unknown; 
                        }
                    } 
 
                    /// 
                    ///     Helper function for QueryInterface. 
                    /// 
                    private static IntPtr InternalQueryInterface(IntPtr pUnk, ref Guid iid) {
                        IntPtr ppv;
                        int hresult = Marshal.QueryInterface(pUnk, ref iid, out ppv); 
                        if (hresult != 0 || ppv == IntPtr.Zero) {
                            throw new InvalidCastException(SR.GetString(SR.AxInterfaceNotSupported)); 
                        } 
                        return ppv;
                    } 

                    /// 
                    ///     Return whether the handle is invalid.
                    ///  
                    public sealed override bool IsInvalid {
                        get { 
                            if (!base.IsClosed) { 
                                return (IntPtr.Zero == base.handle);
                            } 
                            return true;
                        }
                    }
 
                    /// 
                    ///     Release the IUnknown. 
                    ///  
                    protected sealed override bool ReleaseHandle() {
                        IntPtr ptr1 = base.handle; 
                        base.handle = IntPtr.Zero;
                        if (IntPtr.Zero != ptr1) {
                            Marshal.Release(ptr1);
                        } 
                        return true;
                    } 
 
                    /// 
                    ///     Helper function to load a COM v-table from a com object pointer. 
                    /// 
                    protected V LoadVtable() {
                        IntPtr vtblptr = Marshal.ReadIntPtr(this.handle, 0);
                        return (V)Marshal.PtrToStructure(vtblptr, typeof(V)); 
                    }
                } 
 
                /// 
                ///     Helper class to access IConnectionPointContainer from a .NET COM-callable wrapper. 
                ///     The IConnectionPointContainer COM pointer is wrapped in a SafeHandle.
                /// 
                internal sealed class ComConnectionPointContainer
                    : SafeIUnknown { 

                    public ComConnectionPointContainer(object obj, bool addRefIntPtr) 
                        : base(obj, addRefIntPtr, typeof(System.Runtime.InteropServices.ComTypes.IConnectionPointContainer).GUID) { 
                        this.vtbl = base.LoadVtable();
                    } 

                    private VTABLE vtbl;

                    [SuppressMessage("Microsoft.Performance", "CA1812:AvoidUninstantiatedInternalClasses")] 
                    [StructLayout(LayoutKind.Sequential)]
                    private class VTABLE { 
                        public IntPtr QueryInterfacePtr; 
                        public IntPtr AddRefPtr;
                        public IntPtr ReleasePtr; 
                        public IntPtr EnumConnectionPointsPtr;
                        public IntPtr FindConnectionPointPtr;
                    }
 
                    /// 
                    ///     Call IConnectionPointContainer.FindConnectionPoint using Delegate.Invoke on the v-table slot. 
                    ///  
                    public ComConnectionPoint FindConnectionPoint(Type eventInterface) {
                        FindConnectionPointD findConnectionPoint = (FindConnectionPointD)Marshal.GetDelegateForFunctionPointer(this.vtbl.FindConnectionPointPtr, typeof(FindConnectionPointD)); 
                        IntPtr result = IntPtr.Zero;

                        Guid iid = eventInterface.GUID;
                        int hresult = findConnectionPoint.Invoke(this.handle, ref iid, out result); 
                        if (hresult != 0 || result == IntPtr.Zero) {
                            throw new ArgumentException(SR.GetString(SR.AXNoConnectionPoint, eventInterface.Name)); 
                        } 

                        return new ComConnectionPoint(result, false);   // result is already ref-counted as an out-param so pass in false 
                    }

                    [UnmanagedFunctionPointerAttribute(CallingConvention.StdCall)]
                    private delegate int FindConnectionPointD(IntPtr This, ref Guid iid, out IntPtr ppv); 
                }
 
                ///  
                ///     Helper class to access IConnectionPoint from a .NET COM-callable wrapper.
                ///     The IConnectionPoint COM pointer is wrapped in a SafeHandle. 
                /// 
                internal sealed class ComConnectionPoint
                    : SafeIUnknown {
 
                    public ComConnectionPoint(object obj, bool addRefIntPtr)
                        : base(obj, addRefIntPtr, typeof(System.Runtime.InteropServices.ComTypes.IConnectionPoint).GUID) { 
                        this.vtbl = this.LoadVtable(); 
                    }
 
                    [SuppressMessage("Microsoft.Performance", "CA1812:AvoidUninstantiatedInternalClasses")]
                    [StructLayout(LayoutKind.Sequential)]
                    private class VTABLE {
                        public IntPtr QueryInterfacePtr; 
                        public IntPtr AddRefPtr;
                        public IntPtr ReleasePtr; 
                        public IntPtr GetConnectionInterfacePtr; 
                        public IntPtr GetConnectionPointContainterPtr;
                        public IntPtr AdvisePtr; 
                        public IntPtr UnadvisePtr;
                        public IntPtr EnumConnectionsPtr;
                    }
 
                    private VTABLE vtbl;
 
                    ///  
                    ///     Call IConnectioinPoint.Advise using Delegate.Invoke on the v-table slot.
                    ///  
                    public bool Advise(IntPtr punkEventSink, out int cookie) {
                        AdviseD advise = (AdviseD)Marshal.GetDelegateForFunctionPointer(this.vtbl.AdvisePtr, typeof(AdviseD));
                        if (advise.Invoke(this.handle, punkEventSink, out cookie) == 0) {
                            return true; 
                        }
                        return false; 
                    } 

                    [UnmanagedFunctionPointerAttribute(CallingConvention.StdCall)] 
                    private delegate int AdviseD(IntPtr This, IntPtr punkEventSink, out int cookie);
                }

            } 

            ///  
            ///     Return the default COM events interface declared on a .NET class. 
            ///     This looks for the ComSourceInterfacesAttribute and returns the .NET
            ///     interface type of the first interface declared. 
            /// 
            private static Type GetDefaultEventsInterface(Type controlType) {

                Type eventInterface = null; 
                object[] custom = controlType.GetCustomAttributes(typeof(ComSourceInterfacesAttribute), false);
 
                if (custom.Length > 0) { 
                    ComSourceInterfacesAttribute coms = (ComSourceInterfacesAttribute)custom[0];
                    string eventName = coms.Value.Split(new char[] { '\0' })[0]; 
                    eventInterface = controlType.Module.Assembly.GetType(eventName, false);
                    if (eventInterface == null) {
                        eventInterface = Type.GetType(eventName, false);
                    } 
                }
 
                return eventInterface; 
            }
 

            /// 
            /// 
            ///      Implements IPersistStorage::Save 
            /// 
            internal void Save(UnsafeNativeMethods.IStorage stg, bool fSameAsLoad) { 
                UnsafeNativeMethods.IStream stream = null; 

                IntSecurity.UnmanagedCode.Assert(); 
                try {
                    stream = stg.CreateStream(this.GetStreamName(), NativeMethods.STGM_WRITE | NativeMethods.STGM_SHARE_EXCLUSIVE | NativeMethods.STGM_CREATE, 0, 0);
                }
                finally { 
                    CodeAccessPermission.RevertAssert();
                } 
                Debug.Assert(stream != null, "Stream should be non-null, or an exception should have been thrown."); 
                Save(stream, true);
                UnsafeNativeMethods.ReleaseComObject(stream); 
            }

            /// 
            ///  
            ///      Implements IPersistStreamInit::Save
            ///  
            internal void Save(UnsafeNativeMethods.IStream stream, bool fClearDirty) { 
                // We do everything through property bags because we support full fidelity
                // in them.  So, save through that method. 
                //
                PropertyBagStream bag = new PropertyBagStream();
                Save(bag, fClearDirty, false);
                IntSecurity.UnmanagedCode.Assert(); 
                try {
                    bag.Write(stream); 
                } 
                finally {
                    CodeAccessPermission.RevertAssert(); 
                }
                if (UnsafeNativeMethods.IsComObject(stream)) {
                    UnsafeNativeMethods.ReleaseComObject(stream);
                } 
            }
 
            ///  
            ///      Implements IPersistPropertyBag::Save
            ///  
            [SecurityPermission(SecurityAction.Assert, Flags=SecurityPermissionFlag.UnmanagedCode)]
            internal void Save(UnsafeNativeMethods.IPropertyBag pPropBag, bool fClearDirty, bool fSaveAllProperties) {
                PropertyDescriptorCollection props = TypeDescriptor.GetProperties(control,
                    new Attribute[] {DesignerSerializationVisibilityAttribute.Visible}); 

                for (int i = 0; i < props.Count; i++) { 
                    if (fSaveAllProperties || props[i].ShouldSerializeValue(control)) { 
                        Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "Saving property " + props[i].Name);
 
                        object propValue;

                        if (IsResourceProp(props[i])) {
 
                            // Resource property.  Save this to the bag as a 64bit encoded string.
                            // 
                            MemoryStream stream = new MemoryStream(); 
                            BinaryFormatter formatter = new BinaryFormatter();
                            formatter.Serialize(stream, props[i].GetValue(control)); 
                            byte[] bytes = new byte[(int)stream.Length];
                            stream.Position = 0;
                            stream.Read(bytes, 0, bytes.Length);
                            propValue = Convert.ToBase64String(bytes); 
                            pPropBag.Write(props[i].Name, ref propValue);
                        } 
                        else { 

                            // Not a resource property.  Persist this using standard type converters. 
                            //
                            TypeConverter converter = props[i].Converter;
                            Debug.Assert(converter != null, "No type converter for property '" + props[i].Name + "' on class " + control.GetType().FullName);
 
                            if (converter.CanConvertFrom(typeof(string))) {
                                propValue = converter.ConvertToInvariantString(props[i].GetValue(control)); 
                                pPropBag.Write(props[i].Name, ref propValue); 
                            }
                            else if (converter.CanConvertFrom(typeof(byte[]))) { 
                                byte[] data = (byte[])converter.ConvertTo(null, CultureInfo.InvariantCulture, props[i].GetValue(control), typeof(byte[]));
                                propValue = Convert.ToBase64String(data);
                                pPropBag.Write(props[i].Name, ref propValue);
                            } 
                        }
                    } 
                } 

                if (UnsafeNativeMethods.IsComObject(pPropBag)) { 
                    UnsafeNativeMethods.ReleaseComObject(pPropBag);
                }

                if (fClearDirty) { 
                    activeXState[isDirty] = false;
                } 
            } 

            ///  
            ///      Fires the OnSave event to all of our IAdviseSink
            ///      listeners.  Used for ActiveXSourcing.
            /// 
            ///  
            private void SendOnSave() {
                int cnt = adviseList.Count; 
                IntSecurity.UnmanagedCode.Assert(); 
                for (int i = 0; i < cnt; i++) {
                    IAdviseSink s = (IAdviseSink)adviseList[i]; 
                    Debug.Assert(s != null, "NULL in our advise list");
                    s.OnSave();
                }
            } 

            ///  
            ///  
            ///      Implements IViewObject2::SetAdvise.
            ///  
            internal void SetAdvise(int aspects, int advf, IAdviseSink pAdvSink) {
                // if it's not a content aspect, we don't support it.
                //
                if ((aspects & NativeMethods.DVASPECT_CONTENT) == 0) { 
                    ThrowHr(NativeMethods.DV_E_DVASPECT);
                } 
 
                // set up some flags  [we gotta stash for GetAdvise ...]
                // 
                activeXState[viewAdvisePrimeFirst] = (advf & NativeMethods.ADVF_PRIMEFIRST) != 0 ? true : false;
                activeXState[viewAdviseOnlyOnce] = (advf & NativeMethods.ADVF_ONLYONCE) != 0 ? true : false;

                if (viewAdviseSink != null && UnsafeNativeMethods.IsComObject(viewAdviseSink)) { 
                    UnsafeNativeMethods.ReleaseComObject(viewAdviseSink);
                } 
 
                viewAdviseSink = pAdvSink;
 
                // prime them if they want it [we need to store this so they can get flags later]
                //
                if (activeXState[viewAdvisePrimeFirst]) {
                    ViewChanged(); 
                }
            } 
 
            /// 
            ///  
            ///      Implements IOleObject::SetClientSite.
            /// 
            internal void SetClientSite(UnsafeNativeMethods.IOleClientSite value) {
                if (clientSite != null) { 

                    if (value == null) { 
                        globalActiveXCount--; 

                        if (globalActiveXCount == 0 && IsIE) { 

                            // This the last ActiveX control and we are
                            // being hosted in IE.  Use private reflection
                            // to ask SystemEvents to shutdown.  This is to 
                            // prevent a crash (ASURT 139932).
 
                            // SECREVIEW : The SystemEvents class has a LinkDemand for FullTrust permission but it becomes a full demand 
                            //             on a method called using private reflection.  We need to assert here.
                            //             SystemEvents.Shutdown is a private method intended to be called using private reflection (See commnets 
                            //             on the method definition); it sends a WM_QUIT message to the app broadcast window.
                            //             So it is safe to assert here.
                            //
                            new PermissionSet(PermissionState.Unrestricted).Assert(); 
                            try {
                                MethodInfo method = typeof(SystemEvents).GetMethod("Shutdown", 
                                                                                  BindingFlags.Static | BindingFlags.NonPublic | BindingFlags.InvokeMethod, 
                                                                                  null, new Type[0], new ParameterModifier[0]);
                                Debug.Assert(method != null, "No Shutdown method on SystemEvents"); 
                                if (method != null) {
                                    method.Invoke(null, null);
                                }
                            } 
                            finally {
                                CodeAccessPermission.RevertAssert(); 
                            } 
                        }
                    } 

                    if (UnsafeNativeMethods.IsComObject(clientSite)) {
                        IntSecurity.UnmanagedCode.Assert();
                        try { 
                            Marshal.FinalReleaseComObject(clientSite);
                        } 
                        finally { 
                            CodeAccessPermission.RevertAssert();
                        } 
                    }
                }

                clientSite = value; 

                if (clientSite != null) { 
                    control.Site = new AxSourcingSite(control, clientSite, "ControlAxSourcingSite"); 
                }
                else { 
                    control.Site = null;
                }

                // Get the ambient properties that effect us... 
                //
                Object obj = new Object(); 
                if (GetAmbientProperty(NativeMethods.ActiveX.DISPID_AMBIENT_UIDEAD, ref obj)) { 
                    activeXState[uiDead] = (bool)obj;
                } 

                if (control is IButtonControl && GetAmbientProperty(NativeMethods.ActiveX.DISPID_AMBIENT_UIDEAD, ref obj)) {
                    ((IButtonControl)control).NotifyDefault((bool)obj);
                } 

                if (clientSite == null) { 
                    if (accelTable != IntPtr.Zero) { 
                        UnsafeNativeMethods.DestroyAcceleratorTable(new HandleRef(this, accelTable));
                        accelTable = IntPtr.Zero; 
                        accelCount = -1;
                    }

                    if (IsIE) { 
                        this.control.Dispose();
                    } 
                } 
                else {
                    globalActiveXCount++; 

                    if (globalActiveXCount == 1 && IsIE) {

                        // This the first ActiveX control and we are 
                        // being hosted in IE.  Use private reflection
                        // to ask SystemEvents to start.  Startup will only 
                        // restart system events if we previously shut it down. 
                        // This is to prevent a crash (ASURT 139932).
                        // 
                        // SECREVIEW : The SystemEvents class has a LinkDemand for FullTrust permission but it becomes a full demand
                        //             on a method called using private reflection.  We need to assert here.
                        //             SystemEvents.Shutdown is a private method intended to be called using private reflection (See commnets
                        //             on the method definition); it sends a WM_QUIT message to the app broadcast window. 
                        //             So it is safe to assert here.
                        // 
                        new PermissionSet(PermissionState.Unrestricted).Assert(); 
                        try {
                            MethodInfo method = typeof(SystemEvents).GetMethod("Startup", 
                                                                              BindingFlags.Static | BindingFlags.NonPublic | BindingFlags.InvokeMethod,
                                                                              null, new Type[0], new ParameterModifier[0]);
                            Debug.Assert(method != null, "No Startup method on SystemEvents");
                            if (method != null) { 
                                method.Invoke(null, null);
                            } 
                        } 
                        finally {
                            CodeAccessPermission.RevertAssert(); 
                        }
                    }
                }
                control.OnTopMostActiveXParentChanged(EventArgs.Empty); 
            }
 
            ///  
            ///      Implements IOleObject::SetExtent
            ///  
            [SecurityPermission(SecurityAction.Assert, Flags=SecurityPermissionFlag.UnmanagedCode)]
            internal void SetExtent(int dwDrawAspect, NativeMethods.tagSIZEL pSizel) {
                if ((dwDrawAspect & NativeMethods.DVASPECT_CONTENT) != 0) {
 
                    if (activeXState[changingExtents]) {
                        return; 
                    } 

                    activeXState[changingExtents] = true; 

                    try {
                        Size size = new Size(HiMetricToPixel(pSizel.cx, pSizel.cy));
                        Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "SetExtent : new size:" + size.ToString()); 

                        // If we're in place active, let the in place site set our bounds. 
                        // Otherwise, just set it on our control directly. 
                        //
                        if (activeXState[inPlaceActive]) { 
                            UnsafeNativeMethods.IOleInPlaceSite ioleClientSite = clientSite as UnsafeNativeMethods.IOleInPlaceSite;
                            if (ioleClientSite != null) {
                                Rectangle bounds = control.Bounds;
                                bounds.Location = new Point(bounds.X, bounds.Y); 
                                Size adjusted = new Size(size.Width, size.Height);
                                bounds.Width = adjusted.Width; 
                                bounds.Height = adjusted.Height; 
                                Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "SetExtent : Announcing to in place site that our rect has changed.");
                                Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "            Announcing rect = " + bounds); 
                                Debug.Assert(clientSite != null, "How can we setextent before we are sited??");

                                ioleClientSite.OnPosRectChange(NativeMethods.COMRECT.FromXYWH(bounds.X, bounds.Y, bounds.Width, bounds.Height));
                            } 
                        }
 
                        control.Size = size; 

                        // Check to see if the control overwrote our size with 
                        // its own values.
                        //
                        if (!control.Size.Equals(size)) {
                            Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "SetExtent : Control has changed size.  Setting dirty bit"); 
                            activeXState[isDirty] = true;
 
                            // If we're not inplace active, then anounce that the view changed. 
                            //
                            if (!activeXState[inPlaceActive]) { 
                                ViewChanged();
                            }

                            // We need to call RequestNewObjectLayout 
                            // here so we visually display our new extents.
                            // 
                            if (!activeXState[inPlaceActive] && clientSite != null) { 
                                Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "SetExtent : Requesting new Object layout.");
                                clientSite.RequestNewObjectLayout(); 
                            }
                        }
                    }
                    finally { 
                        activeXState[changingExtents] = false;
                    } 
                } 
                else {
                    // We don't support any other aspects 
                    //
                    ThrowHr(NativeMethods.DV_E_DVASPECT);
                }
            } 

            ///  
            ///      Marks our state as in place visible. 
            /// 
            private void SetInPlaceVisible(bool visible) { 
                activeXState[inPlaceVisible] = visible;
                control.Visible = visible;
            }
 
            /// 
            ///      Implements IOleInPlaceObject::SetObjectRects. 
            ///  
            internal void SetObjectRects(NativeMethods.COMRECT lprcPosRect, NativeMethods.COMRECT lprcClipRect) {
 
#if DEBUG
                if (CompModSwitches.ActiveX.TraceInfo) {
                    Debug.WriteLine("SetObjectRects:");
                    Debug.Indent(); 

                    if (lprcPosRect != null) { 
                        Debug.WriteLine("PosLeft:    " + lprcPosRect.left.ToString(CultureInfo.InvariantCulture)); 
                        Debug.WriteLine("PosTop:     " + lprcPosRect.top.ToString(CultureInfo.InvariantCulture));
                        Debug.WriteLine("PosRight:   " + lprcPosRect.right.ToString(CultureInfo.InvariantCulture)); 
                        Debug.WriteLine("PosBottom:  " + lprcPosRect.bottom.ToString(CultureInfo.InvariantCulture));
                    }

                    if (lprcClipRect != null) { 
                        Debug.WriteLine("ClipLeft:   " + lprcClipRect.left.ToString(CultureInfo.InvariantCulture));
                        Debug.WriteLine("ClipTop:    " + lprcClipRect.top.ToString(CultureInfo.InvariantCulture)); 
                        Debug.WriteLine("ClipRight:  " + lprcClipRect.right.ToString(CultureInfo.InvariantCulture)); 
                        Debug.WriteLine("ClipBottom: " + lprcClipRect.bottom.ToString(CultureInfo.InvariantCulture));
                    } 
                    Debug.Unindent();
                }
#endif
 
                Rectangle posRect = Rectangle.FromLTRB(lprcPosRect.left, lprcPosRect.top, lprcPosRect.right, lprcPosRect.bottom);
 
                Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "Set control bounds: " + posRect.ToString()); 

                // ActiveX expects to be notified when a control's bounds change, and also 
                // intends to notify us through SetObjectRects when we report that the
                // bounds are about to change.  We implement this all on a control's Bounds
                // property, which doesn't use this callback mechanism.  The adjustRect
                // member handles this. If it is non-null, then we are being called in 
                // response to an OnPosRectChange call.  In this case we do not
                // set the control bounds but set the bounds on the adjustRect.  When 
                // this returns from the container and comes back to our OnPosRectChange 
                // implementation, these new bounds will be handed back to the control
                // for the actual window change. 
                //
                Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "Old Control Bounds: " + control.Bounds);
                if (activeXState[adjustingRect]) {
                    adjustRect.left = posRect.X; 
                    adjustRect.top = posRect.Y;
                    adjustRect.right = posRect.Width + posRect.X; 
                    adjustRect.bottom = posRect.Height + posRect.Y; 
                }
                else { 
                    activeXState[adjustingRect] = true;
                    try {
                        control.Bounds = posRect;
                    } 
                    finally {
                        activeXState[adjustingRect] = false; 
                    } 
                }
 
                bool setRegion = false;

                if (clipRegion != IntPtr.Zero) {
                    // Bad -- after calling SetWindowReg, windows owns the region. 
                    //SafeNativeMethods.DeleteObject(clipRegion);
                    clipRegion = IntPtr.Zero; 
                    setRegion = true; 
                }
 
                if (lprcClipRect != null) {

                    // The container wants us to clip, so figure out if we really
                    // need to. 
                    //
                    Rectangle clipRect = Rectangle.FromLTRB(lprcClipRect.left, lprcClipRect.top, lprcClipRect.right, lprcClipRect.bottom); 
 
                    Rectangle intersect;
 
                    // Trident always sends an empty ClipRect... and so, we check for that and not do an
                    // intersect in that case.
                    //
                    if (!clipRect.IsEmpty) 
                        intersect = Rectangle.Intersect(posRect, clipRect);
                    else 
                        intersect = posRect; 

                    if (!intersect.Equals(posRect)) { 

                        // Offset the rectangle back to client coordinates
                        //
                        NativeMethods.RECT rcIntersect = NativeMethods.RECT.FromXYWH(intersect.X, intersect.Y, intersect.Width, intersect.Height); 
                        IntPtr hWndParent = UnsafeNativeMethods.GetParent(new HandleRef(control, control.Handle));
 
                        Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "Old Intersect: " + new Rectangle(rcIntersect.left, rcIntersect.top, rcIntersect.right-rcIntersect.left, rcIntersect.bottom-rcIntersect.top)); 
                        Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "New Control Bounds: " + posRect);
 
                        UnsafeNativeMethods.MapWindowPoints(new HandleRef(null, hWndParent), new HandleRef(control, control.Handle), ref rcIntersect, 2);

                        Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "New Intersect: " + new Rectangle(rcIntersect.left, rcIntersect.top, rcIntersect.right-rcIntersect.left, rcIntersect.bottom-rcIntersect.top));
 
                        // Create a Win32 region for it
                        // 
                        clipRegion = SafeNativeMethods.CreateRectRgn(rcIntersect.left, rcIntersect.top, 
                                                                 rcIntersect.right, rcIntersect.bottom);
                        setRegion = true; 
                        Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "Created clipping region");
                    }
                }
 
                // If our region has changed, set the new value.  We only do this if
                // the handle has been created, since otherwise the control will 
                // merge our region automatically. 
                //
                if (setRegion && control.IsHandleCreated) { 
                    IntPtr finalClipRegion = clipRegion;

                    Region controlRegion = control.Region;
                    if (controlRegion != null) { 
                        IntPtr rgn = control.GetHRgn(controlRegion);
                        finalClipRegion = MergeRegion(rgn); 
                    } 

                    UnsafeNativeMethods.SetWindowRgn(new HandleRef(control, control.Handle), new HandleRef(this, finalClipRegion), SafeNativeMethods.IsWindowVisible(new HandleRef(control, control.Handle))); 
                }

                // Yuck.  Forms^3 uses transparent overlay windows that appear to cause
                // painting artifacts.  Flicker like a banshee. 
                //
                control.Invalidate(); 
            } 

            #if ACTIVEX_SOURCING 

            //
            // This has been cut from the product.
            // 

            ///  
            ///      Shows a property page dialog. 
            /// 
            private void ShowProperties() { 
                if (propPage == null) {
                    propPage = new ActiveXPropPage(control);
                }
 
                if (inPlaceFrame != null) {
                    inPlaceFrame.EnableModeless(0); 
                } 
                try {
                    propPage.Edit(control); 
                }
                finally {
                    if (inPlaceFrame != null) {
                        inPlaceFrame.EnableModeless(1); 
                    }
                } 
            } 
            #endif
 
            /// 
            /// 
            ///      Throws the given hresult.  This is used by ActiveX sourcing.
            ///  
            internal static void ThrowHr(int hr) {
                ExternalException e = new ExternalException(SR.GetString(SR.ExternalException), hr); 
                throw e; 
            }
 
            /// 
            /// 
            ///     Handles IOleControl::TranslateAccelerator
            ///  
            internal int TranslateAccelerator(ref NativeMethods.MSG lpmsg) {
 
 
#if DEBUG
                if (CompModSwitches.ActiveX.TraceInfo) { 
                    if (!control.IsHandleCreated) {
                        Debug.WriteLine("AxSource: TranslateAccelerator before handle creation");
                    }
                    else { 
                        Message m = Message.Create(lpmsg.hwnd, lpmsg.message, lpmsg.wParam, lpmsg.lParam);
                        Debug.WriteLine("AxSource: TranslateAccelerator : " + m.ToString()); 
                    } 
                }
#endif // DEBUG 

                bool needPreProcess = false;

                switch (lpmsg.message) { 
                    case NativeMethods.WM_KEYDOWN:
                    case NativeMethods.WM_SYSKEYDOWN: 
                    case NativeMethods.WM_CHAR: 
                    case NativeMethods.WM_SYSCHAR:
                        needPreProcess = true; 
                        break;
                }

                Message msg = Message.Create(lpmsg.hwnd, lpmsg.message, lpmsg.wParam, lpmsg.lParam); 

                if (needPreProcess) { 
                    Control target = Control.FromChildHandleInternal(lpmsg.hwnd); 
                    if (target != null && (control == target || control.Contains(target))) {
                        PreProcessControlState messageState = PreProcessControlMessageInternal(target, ref msg); 
                        switch (messageState) {
                            case PreProcessControlState.MessageProcessed:
                                // someone returned true from PreProcessMessage
                                // no need to dispatch the message, its already been coped with. 
                                lpmsg.message = msg.Msg;
                                lpmsg.wParam = msg.WParam; 
                                lpmsg.lParam = msg.LParam; 
                                return NativeMethods.S_OK;
                            case PreProcessControlState.MessageNeeded: 
                                // VSWhidbey 515519: Here we need to dispatch the message ourselves
                                // otherwise the host may never send the key to our wndproc.

                                // Someone returned true from IsInputKey or IsInputChar 
                                UnsafeNativeMethods.TranslateMessage(ref lpmsg);
                                if (SafeNativeMethods.IsWindowUnicode(new HandleRef(null, lpmsg.hwnd))) { 
                                    UnsafeNativeMethods.DispatchMessageW(ref lpmsg); 
                                }
                                else { 
                                    UnsafeNativeMethods.DispatchMessageA(ref lpmsg);
                                }
                                return NativeMethods.S_OK;
                            case PreProcessControlState.MessageNotNeeded: 
                                // in this case we'll check the site to see if it wants the message.
                                break; 
                        } 
                    }
                } 


                // SITE processing.  We're not interested in the message, but the site may be.
 
                int hr = NativeMethods.S_FALSE;
 
                Debug.WriteLineIf(CompModSwitches.ActiveX.TraceInfo, "AxSource: Control did not process accelerator, handing to site"); 

                UnsafeNativeMethods.IOleControlSite ioleClientSite = clientSite as UnsafeNativeMethods.IOleControlSite; 
                if (ioleClientSite != null) {
                    int keyState = 0;

                    if (UnsafeNativeMethods.GetKeyState(NativeMethods.VK_SHIFT) < 0)     keyState |= 1; 
                    if (UnsafeNativeMethods.GetKeyState(NativeMethods.VK_CONTROL) < 0)   keyState |= 2;
                    if (UnsafeNativeMethods.GetKeyState(NativeMethods.VK_MENU) < 0)      keyState |= 4; 
                    IntSecurity.UnmanagedCode.Assert(); 
                    try {
                        hr = ioleClientSite.TranslateAccelerator(ref lpmsg, keyState); 
                    }
                    finally {
                        CodeAccessPermission.RevertAssert();
                    } 
                }
 
                return hr; 
            }
 
            /// 
            /// 
            ///      Implements IOleInPlaceObject::UIDeactivate.
            ///  
            internal int UIDeactivate() {
                // Only do this if we're UI active 
                // 
                if (!activeXState[uiActive]) {
                    return NativeMethods.S_OK; 
                }

                activeXState[uiActive] = false;
 
                // Notify frame windows, if appropriate, that we're no longer ui-active.
                // 
                if (inPlaceUiWindow != null) { 
                    inPlaceUiWindow.SetActiveObject(null, null);
                } 

                //May need this for SetActiveObject & OnUIDeactivate, so leave until function return
                IntSecurity.UnmanagedCode.Assert();
                Debug.Assert(inPlaceFrame != null, "No inplace frame -- how dod we go UI active?"); 
                inPlaceFrame.SetActiveObject(null, null);
 
                UnsafeNativeMethods.IOleInPlaceSite ioleClientSite = clientSite as UnsafeNativeMethods.IOleInPlaceSite; 
                if (ioleClientSite != null) {
                    ioleClientSite.OnUIDeactivate(0); 
                }

                return NativeMethods.S_OK;
            } 

            ///  
            ///  
            ///      Implements IOleObject::Unadvise
            ///  
            internal void Unadvise(int dwConnection) {
                if (dwConnection > adviseList.Count || adviseList[dwConnection - 1] == null) {
                    ThrowHr(NativeMethods.OLE_E_NOCONNECTION);
                } 

                IAdviseSink sink = (IAdviseSink)adviseList[dwConnection - 1]; 
                adviseList.RemoveAt(dwConnection - 1); 
                if (sink != null && UnsafeNativeMethods.IsComObject(sink)) {
                    UnsafeNativeMethods.ReleaseComObject(sink); 
                }
            }

            ///  
            ///     Notifies our site that we have changed our size and location.
            ///  
            ///  
            internal void UpdateBounds(ref int x, ref int y, ref int width, ref int height, int flags) {
                if (!activeXState[adjustingRect] && activeXState[inPlaceVisible]) { 
                    UnsafeNativeMethods.IOleInPlaceSite ioleClientSite = clientSite as UnsafeNativeMethods.IOleInPlaceSite;
                    if (ioleClientSite != null) {
                        NativeMethods.COMRECT rc = new NativeMethods.COMRECT();
 
                        if ((flags & NativeMethods.SWP_NOMOVE) != 0) {
                            rc.left = control.Left; 
                            rc.top = control.Top; 
                        }
                        else { 
                            rc.left = x;
                            rc.top = y;
                        }
 
                        if ((flags & NativeMethods.SWP_NOSIZE) != 0) {
                            rc.right = rc.left + control.Width; 
                            rc.bottom = rc.top + control.Height; 
                        }
                        else { 
                            rc.right = rc.left + width;
                            rc.bottom = rc.top + height;
                        }
 
                        // This member variable may be modified by SetObjectRects by the container.
                        adjustRect = rc; 
                        activeXState[adjustingRect] = true; 

                        IntSecurity.UnmanagedCode.Assert(); 
                        try {
                            ioleClientSite.OnPosRectChange(rc);
                        }
                        finally { 
                            CodeAccessPermission.RevertAssert();
                            adjustRect = null; 
                            activeXState[adjustingRect] = false; 
                        }
 
                        // On output, the new bounds will be reflected in  rc
                        if ((flags & NativeMethods.SWP_NOMOVE) == 0) {
                            x = rc.left;
                            y = rc.top; 
                        }
                        if ((flags & NativeMethods.SWP_NOSIZE) == 0) { 
                            width = rc.right - rc.left; 
                            height = rc.bottom - rc.top;
                        } 
                    }
                }
            }
 
            /// 
            ///      Notifies that the accelerator table needs to be updated due to a change in a control mnemonic. 
            ///  
            [SuppressMessage("Microsoft.Security", "CA2106:SecureAsserts")]
            internal void UpdateAccelTable(){ 
                // Setting the count to -1 will recreate the table on demand (when GetControlInfo is called).
                this.accelCount = -1;

                UnsafeNativeMethods.IOleControlSite ioleClientSite = clientSite as UnsafeNativeMethods.IOleControlSite; 
                if (ioleClientSite != null) {
                    IntSecurity.UnmanagedCode.Assert(); 
                    ioleClientSite.OnControlInfoChanged(); 
                }
            } 

            // Since this method is used by Reflection .. dont change the "signature"
            [SuppressMessage("Microsoft.Security", "CA2106:SecureAsserts")]
            internal void ViewChangedInternal() 
            {
                ViewChanged(); 
            } 

            ///  
            ///      Notifies our view advise sink (if it exists) that the view has
            ///      changed.
            /// 
            ///  
            [SuppressMessage("Microsoft.Security", "CA2106:SecureAsserts")]
            private void ViewChanged() { 
                // send the view change notification to anybody listening. 
                //
                // Note: Word2000 won't resize components correctly if an OnViewChange notification 
                //       is sent while the component is persisting it's state.  The !m_fSaving check
                //       is to make sure we don't call OnViewChange in this case.
                //
                if (viewAdviseSink != null && !activeXState[saving]) { 
                    IntSecurity.UnmanagedCode.Assert();
                    try { 
                        viewAdviseSink.OnViewChange(NativeMethods.DVASPECT_CONTENT, -1); 
                    }
                    finally { 
                        CodeAccessPermission.RevertAssert();
                    }

                    if (activeXState[viewAdviseOnlyOnce]) { 
                        if (UnsafeNativeMethods.IsComObject(viewAdviseSink)) {
                            UnsafeNativeMethods.ReleaseComObject(viewAdviseSink); 
                        } 
                        viewAdviseSink = null;
                    } 
                }
            }

            ///  
            ///      Called when the window handle of the control has changed.
            ///  
            void IWindowTarget.OnHandleChange(IntPtr newHandle) { 
                controlWindowTarget.OnHandleChange(newHandle);
            } 

            /// 
            ///      Called to do control-specific processing for this window.
            ///  
            void IWindowTarget.OnMessage(ref Message m) {
                if (activeXState[uiDead]) { 
                    if (m.Msg >= NativeMethods.WM_MOUSEFIRST && m.Msg <= NativeMethods.WM_MOUSELAST) { 
                        return;
                    } 
                    if (m.Msg >= NativeMethods.WM_NCLBUTTONDOWN && m.Msg <= NativeMethods.WM_NCMBUTTONDBLCLK) {
                        return;
                    }
                    if (m.Msg >= NativeMethods.WM_KEYFIRST && m.Msg <= NativeMethods.WM_KEYLAST) { 
                        return;
                    } 
                } 

                IntSecurity.UnmanagedCode.Assert(); 
                controlWindowTarget.OnMessage(ref m);
            }

            ///  
            ///      This is a property bag implementation that sits on a stream.  It can
            ///      read and write the bag to the stream. 
            ///  
            private class PropertyBagStream : UnsafeNativeMethods.IPropertyBag {
                private Hashtable bag = new Hashtable(); 

                [SecurityPermission(SecurityAction.Assert, Flags=SecurityPermissionFlag.UnmanagedCode)]
                internal void Read(UnsafeNativeMethods.IStream istream) {
                    // visual basic's memory streams don't support seeking, so we have to 
                    // work around this limitation here.  We do this by copying
                    // the contents of the stream into a MemoryStream object. 
                    // 
                    Stream stream = new DataStreamFromComStream(istream);
                    const int PAGE_SIZE = 0x1000; // one page (4096b) 
                    byte[] streamData = new byte[PAGE_SIZE];
                    int offset = 0;

                    int count = stream.Read(streamData, offset, PAGE_SIZE); 
                    int totalCount = count;
 
                    while (count == PAGE_SIZE) { 
                        byte[] newChunk = new byte[streamData.Length + PAGE_SIZE];
                        Array.Copy(streamData, newChunk, streamData.Length); 
                        streamData = newChunk;

                        offset += PAGE_SIZE;
                        count = stream.Read(streamData, offset, PAGE_SIZE); 
                        totalCount += count;
                    } 
 
                    stream = new MemoryStream(streamData);
 
                    BinaryFormatter formatter = new BinaryFormatter();
                    try {
                        bag = (Hashtable)formatter.Deserialize(stream);
                    } 
                    catch (Exception e) {
                        if (ClientUtils.IsSecurityOrCriticalException(e)) { 
                            throw; 
                        }
 
                        // Error reading.  Just init an empty hashtable.
                        bag = new Hashtable();
                    }
                } 

                [SecurityPermission(SecurityAction.Assert, Flags = SecurityPermissionFlag.UnmanagedCode)] 
                int UnsafeNativeMethods.IPropertyBag.Read(string pszPropName, ref object pVar, UnsafeNativeMethods.IErrorLog pErrorLog) 
                {
                    if (!bag.Contains(pszPropName)) 
                        return NativeMethods.E_INVALIDARG;

                    pVar = bag[pszPropName];
                    return NativeMethods.S_OK; 
                }
 
                [SecurityPermission(SecurityAction.Assert, Flags = SecurityPermissionFlag.UnmanagedCode)] 
                int UnsafeNativeMethods.IPropertyBag.Write(string pszPropName, ref object pVar)
                { 
                    bag[pszPropName] = pVar;
                    return NativeMethods.S_OK;
                }
 
                [SecurityPermission(SecurityAction.Assert, Flags = SecurityPermissionFlag.UnmanagedCode)]
                internal void Write(UnsafeNativeMethods.IStream istream) 
                { 
                    Stream stream = new DataStreamFromComStream(istream);
                    BinaryFormatter formatter = new BinaryFormatter(); 
                    formatter.Serialize(stream, bag);
                }
            }
        } 

        private class AxSourcingSite : ISite { 
            private IComponent component; 
            private UnsafeNativeMethods.IOleClientSite clientSite;
            private string name; 
            private HtmlShimManager shimManager;


            internal AxSourcingSite(IComponent component, UnsafeNativeMethods.IOleClientSite clientSite, string name) { 
                this.component = component;
                this.clientSite = clientSite; 
                this.name = name; 
            }
 
            /** The component sited by this component site. */
            public IComponent Component {
                get {
                    return component; 
                }
            } 
 
            /** The container in which the component is sited. */
            public IContainer Container { 
                get {
                    return null;
                }
            } 

            public Object GetService(Type service) { 
                object retVal = null; 

                if (service == typeof(HtmlDocument)) { 

                    UnsafeNativeMethods.IOleContainer iOlecontainer;
                    int hr;
                    try { 
                        // SECREVIEW : UnsafeNativeMethods.IOleClientSite demands UnmnagedCode permission like most of our COM interfaces
                        //             so we need to assert here.  This assert is safe, we are checking for specific services we support 
                        //             to return it to the user (COM interface). 
                        //
                        IntSecurity.UnmanagedCode.Assert(); 
                        hr = clientSite.GetContainer(out iOlecontainer);
                    }
                    finally {
                        CodeAccessPermission.RevertAssert(); 
                    }
 
 
                    if (NativeMethods.Succeeded(hr)
                            && (iOlecontainer is UnsafeNativeMethods.IHTMLDocument)) { 
                        if (shimManager == null) {
                            shimManager = new HtmlShimManager();
                        }
 
                        // Security note: There is a demand for FullTrust on HtmlDocument that should apply
                        // to this call. So we don't need to demand here. 
                        retVal = new HtmlDocument(shimManager, iOlecontainer as UnsafeNativeMethods.IHTMLDocument); 
                    }
 
                }
                else if (clientSite.GetType().IsAssignableFrom(service)) {
                    IntSecurity.UnmanagedCode.Demand();
                    retVal = clientSite; 
                }
 
                return retVal; 
            }
 

            /** Indicates whether the component is in design mode. */
            public bool DesignMode {
                get { 
                    return false;
                } 
            } 

            /** 
             * The name of the component.
             */
            public String Name {
                get { return name;} 
                set {
                    if (value == null || name == null) { 
                        name = value; 
                    }
                } 
            }
        }

        ///  
        ///     This is a marshaler object that knows how to marshal IFont to Font
        ///     and back. 
        ///  
        [SuppressMessage("Microsoft.Performance", "CA1812:AvoidUninstantiatedInternalClasses")]
        private class ActiveXFontMarshaler : ICustomMarshaler { 

            private static ActiveXFontMarshaler instance;

            public void CleanUpManagedData(object obj) { 
            }
 
            public void CleanUpNativeData(IntPtr pObj) { 
                Marshal.Release(pObj);
            } 

            internal static ICustomMarshaler GetInstance(string cookie) {
                if (instance == null) {
                    instance = new ActiveXFontMarshaler(); 
                }
                return instance; 
            } 
            public int GetNativeDataSize() {
                return -1; // not a value type, so use -1 
            }

            public IntPtr MarshalManagedToNative(object obj) {
                Font font = (Font)obj; 
                NativeMethods.tagFONTDESC fontDesc = new NativeMethods.tagFONTDESC();
                NativeMethods.LOGFONT logFont = new NativeMethods.LOGFONT(); 
 
                // SECREVIEW : The Font.ToLogFont method is marked with the 'unsafe' modifier cause it needs to write bytes into the logFont struct,
                //             here we are passing that struct so the assert is safe. 
                //
                IntSecurity.ObjectFromWin32Handle.Assert();
                try {
                    font.ToLogFont(logFont); 
                }
                finally { 
                    CodeAccessPermission.RevertAssert(); 
                }
 
                fontDesc.lpstrName = font.Name;
                fontDesc.cySize = (long)(font.SizeInPoints * 10000);
                fontDesc.sWeight = (short)logFont.lfWeight;
                fontDesc.sCharset = logFont.lfCharSet; 
                fontDesc.fItalic = font.Italic;
                fontDesc.fUnderline = font.Underline; 
                fontDesc.fStrikethrough = font.Strikeout; 

                Guid iid = typeof(UnsafeNativeMethods.IFont).GUID; 

                UnsafeNativeMethods.IFont oleFont = UnsafeNativeMethods.OleCreateFontIndirect(fontDesc, ref iid);
                IntPtr pFont = Marshal.GetIUnknownForObject(oleFont);
                IntPtr pIFont; 

                int hr = Marshal.QueryInterface(pFont, ref iid, out pIFont); 
 
                Marshal.Release(pFont);
 
                if (NativeMethods.Failed(hr)) {
                    Marshal.ThrowExceptionForHR(hr);
                }
 
                return pIFont;
            } 
 
            public object MarshalNativeToManaged(IntPtr pObj) {
                UnsafeNativeMethods.IFont nativeFont = (UnsafeNativeMethods.IFont)Marshal.GetObjectForIUnknown(pObj); 
                IntPtr hfont = IntPtr.Zero;

                IntSecurity.UnmanagedCode.Assert();
                try { 
                    hfont = nativeFont.GetHFont();
                } 
                finally { 
                    CodeAccessPermission.RevertAssert();
                } 

                Font font = null;

                IntSecurity.ObjectFromWin32Handle.Assert(); 
                try {
                    font = Font.FromHfont(hfont); 
                } 
                catch (Exception e) {
                    if (ClientUtils.IsSecurityOrCriticalException(e)) { 
                        throw;
                    }

                    font = Control.DefaultFont; 
                }
                finally { 
                    CodeAccessPermission.RevertAssert(); 
                }
 
                return font;
            }
        }
 
        /// 
        ///      Simple verb enumerator. 
        ///  
        private class ActiveXVerbEnum : UnsafeNativeMethods.IEnumOLEVERB {
            private NativeMethods.tagOLEVERB[] verbs; 
            private int current;

            internal ActiveXVerbEnum(NativeMethods.tagOLEVERB[] verbs) {
                this.verbs = verbs; 
                current = 0;
            } 
 
            public int Next(int celt, NativeMethods.tagOLEVERB rgelt, int[] pceltFetched) {
                int fetched = 0; 

                if (celt != 1) {
                    Debug.Fail("Caller of IEnumOLEVERB requested celt > 1, but clr marshalling does not support this.");
                    celt = 1; 
                }
 
                while (celt > 0 && current < verbs.Length) { 
                    rgelt.lVerb = verbs[current].lVerb;
                    rgelt.lpszVerbName = verbs[current].lpszVerbName; 
                    rgelt.fuFlags = verbs[current].fuFlags;
                    rgelt.grfAttribs = verbs[current].grfAttribs;
                    celt--;
                    current++; 
                    fetched++;
                } 
 
                if (pceltFetched != null) {
                    pceltFetched[0] = fetched; 
                }

#if DEBUG
                if (CompModSwitches.ActiveX.TraceInfo) { 
                    Debug.WriteLine("AxSource:IEnumOLEVERB::Next returning " + fetched.ToString(CultureInfo.InvariantCulture) + " verbs:");
                    Debug.Indent(); 
                    for (int i = current - fetched; i < current; i++) { 
                        Debug.WriteLine(i.ToString(CultureInfo.InvariantCulture) + ": " + verbs[i].lVerb + " " + (verbs[i].lpszVerbName == null ? string.Empty : verbs[i].lpszVerbName));
                    } 
                    Debug.Unindent();
                }
#endif
                return(celt == 0 ? NativeMethods.S_OK : NativeMethods.S_FALSE); 
            }
 
            public int Skip(int celt) { 
                if (current + celt < verbs.Length) {
                    current += celt; 
                    return NativeMethods.S_OK;
                }
                else {
                    current = verbs.Length; 
                    return NativeMethods.S_FALSE;
                } 
            } 

            public void Reset() { 
                current = 0;
            }

            public void Clone(out UnsafeNativeMethods.IEnumOLEVERB ppenum) { 
                ppenum = new ActiveXVerbEnum(verbs);
            } 
        } 

        #if ACTIVEX_SOURCING 

        //
        // This has been cut from the product.
        // 

        ///  
        ///     The properties window we display. 
        /// 
        private class ActiveXPropPage { 
            private Form form;
            private PropertyGrid grid;
            private ComponentEditor compEditor;
 
            internal ActiveXPropPage(object component) {
                compEditor = (ComponentEditor)TypeDescriptor.GetEditor(component, typeof(ComponentEditor)); 
 
                if (compEditor == null) {
                    form = new Form(); 
                    grid = new PropertyGrid();

                    form.Text = SR.GetString(SR.AXProperties);
                    form.StartPosition = FormStartPosition.CenterParent; 
                    form.Size = new Size(300, 350);
                    form.FormBorderStyle = FormBorderStyle.Sizable; 
                    form.MinimizeBox = false; 
                    form.MaximizeBox = false;
                    form.ControlBox = true; 
                    form.SizeGripStyle = SizeGripStyle.Show;
                    form.DockPadding.Bottom = 16; // size grip size

                    Bitmap bitmap = new Bitmap(grid.GetType(), "PropertyGrid.bmp"); 
                    bitmap.MakeTransparent();
                    form.Icon = Icon.FromHandle(bitmap.GetHicon()); 
 
                    grid.Dock = DockStyle.Fill;
 
                    form.Controls.Add(grid);
                }
            }
 
            internal void Edit(object editingObject) {
                if (compEditor != null) { 
                    compEditor.EditComponent(null, editingObject); 
                }
                else { 
                    grid.SelectedObject = editingObject;
                    form.ShowDialog();
                }
            } 
        }
 
        #endif 

        ///  
        ///      Contains a single ambient property, including DISPID, name and value.
        /// 
        private class AmbientProperty {
            private string name; 
            private int dispID;
            private Object value; 
            private bool empty; 

            ///  
            /// 
            ///      Creates a new, empty ambient property.
            /// 
            internal AmbientProperty(string name, int dispID) { 
                this.name = name;
                this.dispID = dispID; 
                this.value = null; 
                this.empty = true;
            } 

            /// 
            /// 
            ///      The windows forms property name. 
            /// 
            internal string Name { 
                get { 
                    return name;
                } 
            }

            /// 
            ///  
            ///      The DispID for the property.
            ///  
            internal int DispID { 
                get {
                    return dispID; 
                }
            }

            ///  
            /// 
            ///      Returns true if this property has not been set. 
            ///  
            internal bool Empty {
                get { 
                    return empty;
                }
            }
 
            /// 
            ///  
            ///      The current value of the property. 
            /// 
            internal Object Value { 
                get {
                    return value;
                }
                set { 
                    this.value = value;
                    empty = false; 
                } 
            }
 
            /// 
            /// 
            ///      Resets the property.
            ///  
            internal void ResetValue() {
                empty = true; 
                value = null; 
            }
        } 

        /// 
        ///     MetafileDCWrapper is used to wrap a metafile DC so that subsequent
        ///     paint operations are rendered to a temporary bitmap.  When the 
        ///     wrapper is disposed, it copies the bitmap back to the metafile DC.
        /// 
        ///     Example: 
        ///
        ///     using(MetafileDCWrapper dcWrapper = new MetafileDCWrapper(hDC, size) { 
        ///         // ...use dcWrapper.HDC to do painting
        ///     }
        ///
        ///  
        private class MetafileDCWrapper : IDisposable {
 
            HandleRef hBitmapDC     = NativeMethods.NullHandleRef; 
            HandleRef hBitmap       = NativeMethods.NullHandleRef;
            HandleRef hOriginalBmp  = NativeMethods.NullHandleRef; 
            HandleRef hMetafileDC   = NativeMethods.NullHandleRef;
            NativeMethods.RECT destRect;

            [SuppressMessage("Microsoft.Globalization", "CA1303:DoNotPassLiteralsAsLocalizedParameters")] 
            [ResourceExposure(ResourceScope.Machine)]
            [ResourceConsumption(ResourceScope.Process | ResourceScope.Machine, ResourceScope.Process | ResourceScope.Machine)] 
            internal MetafileDCWrapper(HandleRef hOriginalDC, Size size) { 
                Debug.Assert(UnsafeNativeMethods.GetObjectType(hOriginalDC) == NativeMethods.OBJ_ENHMETADC,
                    "Why wrap a non-Enhanced MetaFile DC?"); 

                // Security fix: make sure the size has non-negative width and height.
                if (size.Width < 0 || size.Height < 0) {
                    throw new ArgumentException("size", SR.GetString(SR.ControlMetaFileDCWrapperSizeInvalid)); 
                }
 
                hMetafileDC = hOriginalDC; 
                destRect = new NativeMethods.RECT(0, 0, size.Width, size.Height);
                hBitmapDC = new HandleRef(this, UnsafeNativeMethods.CreateCompatibleDC(NativeMethods.NullHandleRef)); 

                int planes = UnsafeNativeMethods.GetDeviceCaps(hBitmapDC, NativeMethods.PLANES);
                int bitsPixel = UnsafeNativeMethods.GetDeviceCaps(hBitmapDC, NativeMethods.BITSPIXEL);
                hBitmap = new HandleRef(this, SafeNativeMethods.CreateBitmap(size.Width, size.Height, planes, bitsPixel, IntPtr.Zero)); 

                hOriginalBmp = new HandleRef(this, SafeNativeMethods.SelectObject(hBitmapDC, hBitmap)); 
            } 

            ~MetafileDCWrapper() { 
                ((IDisposable) this).Dispose();
            }

            void IDisposable.Dispose() { 
                if (hBitmapDC.Handle == IntPtr.Zero || hMetafileDC.Handle == IntPtr.Zero || hBitmap.Handle == IntPtr.Zero) {
                    return; 
                } 

                bool success; 

                try {
                    success = DICopy(hMetafileDC, hBitmapDC, destRect, true);
                    Debug.Assert(success, "DICopy() failed."); 
                    SafeNativeMethods.SelectObject(hBitmapDC, hOriginalBmp);
                    success = SafeNativeMethods.DeleteObject(hBitmap); 
                    Debug.Assert(success, "DeleteObject() failed."); 
                    success = UnsafeNativeMethods.DeleteCompatibleDC(hBitmapDC);
                    Debug.Assert(success, "DeleteObject() failed."); 
                }
                finally {

                    // Dispose is done. Set all the handles to IntPtr.Zero so this way the Dispose method executes only once. 
                    hBitmapDC = NativeMethods.NullHandleRef;
                    hBitmap = NativeMethods.NullHandleRef; 
                    hOriginalBmp = NativeMethods.NullHandleRef; 

                    GC.SuppressFinalize(this); 
                }
            }

            internal IntPtr HDC { 
                get { return hBitmapDC.Handle; }
            } 
 
            // ported form VB6 (Ctls\PortUtil\StdCtl.cpp:6176)
            private unsafe bool DICopy(HandleRef hdcDest, HandleRef hdcSrc, NativeMethods.RECT rect, bool bStretch) { 
                long i;

                bool fSuccess = false;  // Assume failure
 
                //
                // Get the bitmap from the DC by selecting in a 1x1 pixel temp bitmap 
                HandleRef hNullBitmap = new HandleRef(this, SafeNativeMethods.CreateBitmap(1, 1, 1, 1, IntPtr.Zero)); 
                if (hNullBitmap.Handle == IntPtr.Zero) return fSuccess;
 
                try {
                    HandleRef hBitmap = new HandleRef(this, SafeNativeMethods.SelectObject(hdcSrc, hNullBitmap));
                    if (hBitmap.Handle == IntPtr.Zero) return fSuccess;
 
                    //
                    // Restore original bitmap 
                    SafeNativeMethods.SelectObject(hdcSrc, hBitmap); 

 
                    NativeMethods.BITMAP bmp = new NativeMethods.BITMAP();
                    if (UnsafeNativeMethods.GetObject(hBitmap, Marshal.SizeOf(bmp), bmp) == 0) {
                        return fSuccess;
                    } 

                    NativeMethods.BITMAPINFO_FLAT lpbmi = new NativeMethods.BITMAPINFO_FLAT(); 
                    lpbmi.bmiHeader_biSize = Marshal.SizeOf(typeof(NativeMethods.BITMAPINFOHEADER)); 
                    lpbmi.bmiHeader_biWidth = bmp.bmWidth;
                    lpbmi.bmiHeader_biHeight = bmp.bmHeight; 
                    lpbmi.bmiHeader_biPlanes = 1;
                    lpbmi.bmiHeader_biBitCount = bmp.bmBitsPixel;
                    lpbmi.bmiHeader_biCompression = NativeMethods.BI_RGB;
                    lpbmi.bmiHeader_biSizeImage = 0;               //Not needed since using BI_RGB 
                    lpbmi.bmiHeader_biXPelsPerMeter = 0;
                    lpbmi.bmiHeader_biYPelsPerMeter = 0; 
                    lpbmi.bmiHeader_biClrUsed = 0; 
                    lpbmi.bmiHeader_biClrImportant = 0;
                    lpbmi.bmiColors = new byte[NativeMethods.BITMAPINFO_MAX_COLORSIZE*4]; 

                    //
                    // Include the palette for 256 color bitmaps
                    long iColors = 1 << (bmp.bmBitsPixel * bmp.bmPlanes); 
                    if (iColors <= 256) {
                        byte[] aj = new byte[Marshal.SizeOf(typeof(NativeMethods.PALETTEENTRY)) * 256]; 
                        SafeNativeMethods.GetSystemPaletteEntries(hdcSrc, 0, (int)iColors, aj); 

                        fixed (byte* pcolors = lpbmi.bmiColors) { 
                            fixed (byte* ppal = aj) {
                                NativeMethods.RGBQUAD* prgb = (NativeMethods.RGBQUAD*)pcolors;
                                NativeMethods.PALETTEENTRY* lppe = (NativeMethods.PALETTEENTRY*)ppal;
                                // 
                                // Convert the palette entries to RGB quad entries
                                for (i = 0; i < (int)iColors; i++) { 
                                    prgb[i].rgbRed = lppe[i].peRed; 
                                    prgb[i].rgbBlue = lppe[i].peBlue;
                                    prgb[i].rgbGreen = lppe[i].peGreen; 
                                }
                            }
                        }
                    } 

                    // 
                    // Allocate memory to hold the bitmap bits 
                    long bitsPerScanLine = bmp.bmBitsPixel * (long)bmp.bmWidth;
                    long bytesPerScanLine = (bitsPerScanLine + 7) / 8; 
                    long totalBytesReqd = bytesPerScanLine * bmp.bmHeight;
                    byte[] lpBits = new byte[totalBytesReqd];

                    // 
                    // Get the bitmap bits
                    int diRet = SafeNativeMethods.GetDIBits(hdcSrc, hBitmap, 0, bmp.bmHeight, lpBits, 
                            ref lpbmi, NativeMethods.DIB_RGB_COLORS); 
                    if (diRet == 0) return fSuccess;
 
                    //
                    // Set the destination coordiates depending on whether stretch-to-fit was chosen
                    int xDest, yDest, cxDest, cyDest;
                    if (bStretch) 
                    {
                        xDest = rect.left; 
                        yDest = rect.top; 
                        cxDest = rect.right - rect.left;
                        cyDest = rect.bottom - rect.top; 
                    }
                    else
                    {
                        xDest = rect.left; 
                        yDest = rect.top;
                        cxDest = bmp.bmWidth; 
                        cyDest = bmp.bmHeight; 
                    }
 
                    // Paint the bitmap
                    int iRet = SafeNativeMethods.StretchDIBits(hdcDest,
                            xDest, yDest, cxDest, cyDest, 0, 0, bmp.bmWidth, bmp.bmHeight,
                            lpBits, ref lpbmi, NativeMethods.DIB_RGB_COLORS, NativeMethods.SRCCOPY); 
                    if (iRet == NativeMethods.GDI_ERROR) return fSuccess;
 
                    fSuccess = true; 
                }
                finally { 
                    SafeNativeMethods.DeleteObject(hNullBitmap);
                }
                return fSuccess;
            } 
        }
 
 
        /// 
        ///  
        ///      An implementation of AccessibleChild for use with Controls
        /// 
        [System.Runtime.InteropServices.ComVisible(true)]
        public class ControlAccessibleObject : AccessibleObject { 

            private static IntPtr oleAccAvailable = NativeMethods.InvalidIntPtr; 
 
            // Member variables
 
            private IntPtr handle = IntPtr.Zero; // Associated window handle (if any)
            private Control ownerControl = null; // The associated Control for this AccessibleChild (if any)

            // constructors 

            ///  
            ///  
            ///    [To be supplied.]
            ///  
            public ControlAccessibleObject(Control ownerControl) {

                Debug.Assert(ownerControl != null, "Cannot construct a ControlAccessibleObject with a null ownerControl");
                if (ownerControl == null) { 
                    throw new ArgumentNullException("ownerControl");
                } 
 
                this.ownerControl = ownerControl;
 
                // Reviewed  : ControlAccessibleObject.set_Handle demands UnmanagedCode permission for public use, it doesn't
                //             expose any security vulnerability indirectly. The sec Assert is safe.
                //
                IntSecurity.UnmanagedCode.Assert(); 
                try {
                    this.Handle = ownerControl.Handle; 
                } 
                finally {
                    CodeAccessPermission.RevertAssert(); 
                }
            }

            ///  
            /// 
            ///    [To be supplied.] 
            ///  
            internal ControlAccessibleObject(Control ownerControl, int accObjId) {
 
                Debug.Assert(ownerControl != null, "Cannot construct a ControlAccessibleObject with a null ownerControl");
                if (ownerControl == null) {
                    throw new ArgumentNullException("ownerControl");
                } 

                this.AccessibleObjectId = accObjId; // ...must set this *before* setting the Handle property 
 
                this.ownerControl = ownerControl;
 
                // Reviewed  : ControlAccessibleObject.set_Handle demands UnmanagedCode permission for public use, it doesn't
                //             expose any security vulnerability indirectly. The sec Assert is safe.
                //
                IntSecurity.UnmanagedCode.Assert(); 
                try {
                    this.Handle = ownerControl.Handle; 
                } 
                finally {
                    CodeAccessPermission.RevertAssert(); 
                }
            }

            ///  
            ///     For container controls only, return array of child controls sorted into
            ///     tab index order. This gets applies to the list of child accessible objects 
            ///     as returned by the system, so that we can present a meaningful order to 
            ///     the user. The system defaults to z-order, which is bad for us because
            ///     that is usually the reverse of tab order! 
            /// 
            internal override int[] GetSysChildOrder() {
                if (ownerControl.GetStyle(ControlStyles.ContainerControl))
                    return ownerControl.GetChildWindowsInTabOrder(); 

                return base.GetSysChildOrder(); 
            } 

            ///  
            ///     Perform custom navigation between parent/child/sibling accessible objects,
            ///     using tab index order as the guide, rather than letting the system default
            ///     behavior do navigation based on z-order.
            /// 
            ///     For a container control and its child controls, the accessible object tree
            ///     looks like this... 
            /// 
            ///         [client area of container]
            ///             [non-client area of child #1] 
            ///                 [random non-client elements]
            ///                 [client area of child #1]
            ///                 [random non-client elements]
            ///             [non-client area of child #2] 
            ///                 [random non-client elements]
            ///                 [client area of child #2] 
            ///                 [random non-client elements] 
            ///             [non-client area of child #3]
            ///                 [random non-client elements] 
            ///                 [client area of child #3]
            ///                 [random non-client elements]
            ///
            ///     We need to intercept first-child / last-child navigation from the container's 
            ///     client object, and next-sibling / previous-sibling navigation from each child's
            ///     non-client object. All other navigation operations must be allowed to fall back 
            ///     on the system's deafult behavior (provided by OLEACC.DLL). 
            ///
            ///     When combined with the re-ordering behavior of GetSysChildOrder() above, this 
            ///     allows us to present the end user with the illusion of accessible objects in
            ///     tab index order, even though the system behavior only supports z-order.
            /// 
            internal override bool GetSysChild(AccessibleNavigation navdir, out AccessibleObject accessibleObject) { 

                // Clear the out parameter 
                accessibleObject = null; 

                // Get the owning control's parent, if it has one 
                Control parentControl = ownerControl.ParentInternal;

                // ctrls[index] will indicate the control at the destination of this navigation operation
                int index = -1; 
                Control[] ctrls = null;
 
                // Now handle any 'appropriate' navigation requests... 
                switch (navdir) {
 
                    case AccessibleNavigation.FirstChild:
                        if (IsClientObject) {
                            ctrls = ownerControl.GetChildControlsInTabOrder(true);
                            index = 0; 
                        }
                        break; 
 
                    case AccessibleNavigation.LastChild:
                        if (IsClientObject) { 
                            ctrls = ownerControl.GetChildControlsInTabOrder(true);
                            index = ctrls.Length - 1;
                        }
                        break; 

                    case AccessibleNavigation.Previous: 
                        if (IsNonClientObject && parentControl != null) { 
                            ctrls = parentControl.GetChildControlsInTabOrder(true);
                            index = Array.IndexOf(ctrls, ownerControl); 
                            if (index != -1)
                                --index;
                        }
                        break; 

                    case AccessibleNavigation.Next: 
                        if (IsNonClientObject && parentControl != null) { 
                            ctrls = parentControl.GetChildControlsInTabOrder(true);
                            index = Array.IndexOf(ctrls, ownerControl); 
                            if (index != -1)
                                ++index;
                        }
                        break; 
                }
 
                // Unsupported navigation operation for this object, or unexpected error. 
                // Return false to force fall back on default system navigation behavior.
                if (ctrls == null || ctrls.Length == 0) 
                    return false;

                // If ctrls[index] is a valid control, return its non-client accessible object.
                // If index is invalid, return null pointer meaning "end of list reached". 
                if (index >= 0 && index < ctrls.Length)
                    accessibleObject = ctrls[index].NcAccessibilityObject; 
 
                // Return true to use the found accessible object and block default system behavior
                return true; 
            }

            /// 
            public override string DefaultAction { 
                get {
                    string defaultAction = ownerControl.AccessibleDefaultActionDescription; 
                    if (defaultAction != null) { 
                        return defaultAction;
                    } 
                    else {
                        return base.DefaultAction;
                    }
                } 
            }
 
            ///  
            /// 
            ///    [To be supplied.] 
            /// 
            public override string Description {
                get {
                    string description = ownerControl.AccessibleDescription; 
                    if (description != null) {
                        return description; 
                    } 
                    else {
                        return base.Description; 
                    }
                }
            }
 
            /// 
            ///  
            ///    [To be supplied.] 
            /// 
            public IntPtr Handle { 

                get {
                    return handle;
                } 

                set { 
                    // Demand security permission for this! 
                    IntSecurity.UnmanagedCode.Demand();
 
                    if (handle != value) {
                        handle = value;

                        if (oleAccAvailable == IntPtr.Zero) { 
                            return;
                        } 
 
                        bool freeLib = false;
 
                        if (oleAccAvailable == NativeMethods.InvalidIntPtr) {
                            oleAccAvailable = UnsafeNativeMethods.LoadLibrary("oleacc.dll");
                            freeLib = (oleAccAvailable != IntPtr.Zero);
                        } 

                        // Update systemIAccessible 
                        // We need to store internally the system provided 
                        // IAccessible, because some windows forms controls use it
                        // as the default IAccessible implementation. 
                        if (handle != IntPtr.Zero && oleAccAvailable != IntPtr.Zero) {
                            UseStdAccessibleObjects(handle);
                        }
 
                        if (freeLib) {
                            UnsafeNativeMethods.FreeLibrary(new HandleRef(null, oleAccAvailable)); 
                        } 

                    } 
                } // end Handle.Set

            } // end Handle
 
            /// 
            ///  
            ///    [To be supplied.] 
            /// 
            public override string Help { 
                get {
                    QueryAccessibilityHelpEventHandler handler = (QueryAccessibilityHelpEventHandler)Owner.Events[EventQueryAccessibilityHelp];

                    if (handler != null) { 
                        QueryAccessibilityHelpEventArgs args = new QueryAccessibilityHelpEventArgs();
                        handler(Owner, args); 
                        return args.HelpString; 
                    }
                    else { 
                        return base.Help;
                    }
                }
            } 

            ///  
            public override string KeyboardShortcut { 
                get {
                    // For controls, the default keyboard shortcut comes directly from the accessible 
                    // name property. This matches the default behavior of OLEACC.DLL exactly.
                    char mnemonic = WindowsFormsUtils.GetMnemonic(this.TextLabel, false);
                    return (mnemonic == (char) 0) ? null : ("Alt+" + mnemonic);
                } 
            }
 
            ///  
            /// 
            ///    [To be supplied.] 
            /// 
            public override string Name {
                get {
                    // Special case: If an explicit name has been set in the AccessibleName property, use that. 
                    // Note: Any non-null value in AccessibleName overrides the default accessible name logic,
                    // even an empty string (this is the only way to *force* the accessible name to be blank). 
                    string name = ownerControl.AccessibleName; 
                    if (name != null) {
                        return name; 
                    }

                    // Otherwise just return the default label string, minus any mnemonics
                    return WindowsFormsUtils.TextWithoutMnemonics(TextLabel); 
                }
 
                set { 
                    // If anyone tries to set the accessible name, just cache the value in the control's
                    // AccessibleName property. This value will then end up overriding the normal accessible 
                    // name logic, until such time as AccessibleName is set back to null.
                    ownerControl.AccessibleName = value;
                }
            } 

            ///  
            public override AccessibleObject Parent { 
                [SecurityPermission(SecurityAction.Demand, Flags = SecurityPermissionFlag.UnmanagedCode)]
                [SecurityPermission(SecurityAction.InheritanceDemand, Flags = SecurityPermissionFlag.UnmanagedCode)] 
                get {
                    return base.Parent;
                }
            } 

            // Determine the text that should be used to 'label' this control for accessibility purposes. 
            // 
            // Prior to Whidbey, we just called 'base.Name' to determine the accessible name. This would end up calling
            // OLEACC.DLL to determine the name. The rules used by OLEACC.DLL are the same as what we now have below, 
            // except that OLEACC searches for preceding labels using z-order, and we want to search for labels using
            // TabIndex order.
            //
            internal string TextLabel { 
                get {
                    // If owning control allows, use its Text property - but only if that Text is not empty 
                    if (ownerControl.GetStyle(ControlStyles.UseTextForAccessibility)) { 
                        string text = ownerControl.Text;
                        if (!string.IsNullOrEmpty(text)) { 
                            return text;
                        }
                    }
 
                    // Otherwise use the text of the preceding Label control, if there is one
                    Label previousLabel = PreviousLabel; 
                    if (previousLabel != null) { 
                        string text = previousLabel.Text;
                        if (!string.IsNullOrEmpty(text)) { 
                            return text;
                        }
                    }
 
                    // This control has no discernable MSAA name - return an empty string to indiciate 'nameless'.
                    return null; 
                } 
            }
 
            /// 
            /// 
            ///    [To be supplied.]
            ///  
            public Control Owner {
                get { 
                    return ownerControl; 
                }
            } 

            // Look for a label immediately preceeding this control in
            // the tab order, and use its name for the accessible name.
            // 
            // This method aims to emulate the equivalent behavior in OLEACC.DLL,
            // but walking controls in TabIndex order rather than native z-order. 
            // 
            internal Label PreviousLabel {
                get { 
                    // Try to get to the parent of this control.
                    Control parent = Owner.ParentInternal;

                    if (parent == null) { 
                        return null;
                    } 
 
                    // Find this control's containing control
                    ContainerControl container = parent.GetContainerControlInternal() as ContainerControl; 
                    if (container == null) {
                        return null;
                    }
 
                    // Walk backwards through peer controls...
                    for (Control previous = container.GetNextControl(Owner, false); 
                         previous != null; 
                         previous = container.GetNextControl(previous, false)) {
 
                        // Stop when we hit a Label (whether visible or invisible)
                        if (previous is Label) {
                            return previous as Label;
                        } 

                        // Stop at any *visible* tab stop 
                        if (previous.Visible && previous.TabStop) { 
                            break;
                        } 
                    }

                    return null;
                } 
            }
 
            ///  
            /// 
            ///    [To be supplied.] 
            /// 
            public override AccessibleRole Role {
                get {
                    AccessibleRole role = ownerControl.AccessibleRole; 
                    if (role != AccessibleRole.Default) {
                        return role; 
                    } 
                    else {
                        return base.Role; 
                    }

                }
            } 

            ///  
            ///  
            ///    [To be supplied.]
            ///  
            public override int GetHelpTopic(out string fileName) {
                int topic = 0;

                QueryAccessibilityHelpEventHandler handler = (QueryAccessibilityHelpEventHandler)Owner.Events[EventQueryAccessibilityHelp]; 

                if (handler != null) { 
                    QueryAccessibilityHelpEventArgs args = new QueryAccessibilityHelpEventArgs(); 
                    handler(Owner, args);
 
                    fileName = args.HelpNamespace;
                    if (!String.IsNullOrEmpty(fileName)) {
                        IntSecurity.DemandFileIO(FileIOPermissionAccess.PathDiscovery, fileName);
                    } 

                    try { 
                        topic = Int32.Parse(args.HelpKeyword, CultureInfo.InvariantCulture); 
                    }
                    catch (Exception e) { 
                        if (ClientUtils.IsSecurityOrCriticalException(e)) {
                            throw;
                        }
                    } 

                    return topic; 
                } 
                else {
                    return base.GetHelpTopic(out fileName); 
                }
            }

            ///  
            /// 
            ///    [To be supplied.] 
            ///  
            public void NotifyClients(AccessibleEvents accEvent) {
                Debug.WriteLineIf(CompModSwitches.MSAA.TraceInfo, "Control.NotifyClients: this = " + 
                                  this.ToString() + ", accEvent = " + accEvent.ToString() + ", childID = self");

                UnsafeNativeMethods.NotifyWinEvent((int)accEvent, new HandleRef(this, Handle), NativeMethods.OBJID_CLIENT, 0);
            } 

            ///  
            ///  
            ///    [To be supplied.]
            ///  
            public void NotifyClients(AccessibleEvents accEvent, int childID) {

                Debug.WriteLineIf(CompModSwitches.MSAA.TraceInfo, "Control.NotifyClients: this = " +
                                  this.ToString() + 
                                  ", accEvent = " + accEvent.ToString() +
                                  ", childID = " + childID.ToString(CultureInfo.InvariantCulture)); 
 
                UnsafeNativeMethods.NotifyWinEvent((int)accEvent, new HandleRef(this, Handle), NativeMethods.OBJID_CLIENT, childID + 1);
            } 

            /// 
            /// 
            ///    [To be supplied.] 
            /// 
            public void NotifyClients(AccessibleEvents accEvent, int objectID, int childID) { 
 
                Debug.WriteLineIf(CompModSwitches.MSAA.TraceInfo, "Control.NotifyClients: this = " +
                                  this.ToString() + 
                                  ", accEvent = " + accEvent.ToString() +
                                  ", childID = " + childID.ToString(CultureInfo.InvariantCulture));

                UnsafeNativeMethods.NotifyWinEvent((int)accEvent, new HandleRef(this, Handle), objectID, childID + 1); 
            }
 
            ///  
            /// 
            ///    [To be supplied.] 
            /// 
            public override string ToString() {
                if (Owner != null) {
                    return "ControlAccessibleObject: Owner = " + Owner.ToString(); 
                }
                else { 
                    return "ControlAccessibleObject: Owner = null"; 
                }
            } 
        }


        // Fonts can be a pain to track, so we wrap Hfonts in this class to get a Finalize method. 
        //
        internal sealed class FontHandleWrapper : MarshalByRefObject, IDisposable { 
#if DEBUG 
            private string stackOnCreate = null;
            private string stackOnDispose = null; 
            private bool finalizing = false;
#endif
            private IntPtr handle;
 
            internal FontHandleWrapper(Font font) {
#if DEBUG 
                if (CompModSwitches.LifetimeTracing.Enabled) stackOnCreate = new System.Diagnostics.StackTrace().ToString(); 
#endif
                handle = font.ToHfont(); 
                System.Internal.HandleCollector.Add(handle, NativeMethods.CommonHandles.GDI);
            }

            internal IntPtr Handle { 
                get {
                    Debug.Assert(handle != IntPtr.Zero, "FontHandleWrapper disposed, but still being accessed"); 
                    return handle; 
                }
            } 

            public void Dispose() {
                Dispose(true);
                GC.SuppressFinalize(this); 
            }
 
            private void Dispose(bool disposing) { 

#if DEBUG 
                Debug.Assert(finalizing || this != defaultFontHandleWrapper, "Don't dispose the defaultFontHandleWrapper");
#endif

                if (handle != IntPtr.Zero) { 
#if DEBUG
                    if (CompModSwitches.LifetimeTracing.Enabled) stackOnDispose = new System.Diagnostics.StackTrace().ToString(); 
#endif 
                    SafeNativeMethods.DeleteObject(new HandleRef(this, handle));
                    handle = IntPtr.Zero; 
                }

            }
 
            ~FontHandleWrapper() {
#if DEBUG 
                finalizing = true; 
#endif
                Dispose(false); 
            }
        }

        ///  
        ///     Used with BeginInvoke/EndInvoke
        ///  
        private class ThreadMethodEntry : IAsyncResult { 
            internal Control   caller;
            internal Control   marshaler; 
            internal Delegate  method;
            internal Object[] args;
            internal Object    retVal;
            internal Exception exception; 
            internal bool   synchronous;
            private bool isCompleted; 
            private ManualResetEvent resetEvent; 
            private object invokeSyncObject = new object();
 
            // Store the execution context associated with the caller thread, and
            // information about which thread actually got the stack applied to it.
            //
            internal ExecutionContext executionContext; 

            // Optionally store the synchronization context associated with the callee thread. 
            // This overrides the [....] context in the execution context of the caller thread. 
            //
            internal SynchronizationContext syncContext = null; 

            internal ThreadMethodEntry(Control caller, Control marshaler, Delegate method, Object[] args, bool synchronous, ExecutionContext executionContext) {
                this.caller = caller;
                this.marshaler = marshaler; 
                this.method = method;
                this.args = args; 
                this.exception = null; 
                this.retVal = null;
                this.synchronous = synchronous; 
                this.isCompleted = false;
                this.resetEvent = null;
                this.executionContext = executionContext;
            } 

            ~ThreadMethodEntry() 
            { 
                if (this.resetEvent != null)
                { 
                    this.resetEvent.Close();
                }
            }
 
            public  Object AsyncState {
                get { 
                    return null; 
                }
            } 

            public WaitHandle AsyncWaitHandle {
                get {
                    if (this.resetEvent == null) { 
                        // Locking 'this' here is ok since this is an internal class.  See VSW#464499.
                        lock (invokeSyncObject) { 
                            // VSWhidbey 314175 BeginInvoke hangs on Multi-proc system: 
                            // taking the lock prevents a race condition between IsCompleted
                            // boolean flag and resetEvent mutex in multiproc scenarios. 
                             if (this.resetEvent == null) {
                                this.resetEvent = new ManualResetEvent(false);
                                if (this.isCompleted) {
                                    this.resetEvent.Set(); 
                                }
                             } 
                        } 
                    }
                    return(WaitHandle)this.resetEvent; 
                }
            }

            public bool CompletedSynchronously { 
                get {
                    if (this.isCompleted && this.synchronous) 
                        return true; 

                    return false; 
                }
            }

            public bool IsCompleted { 
                get {
                    return this.isCompleted; 
                } 
            }
 
            internal void Complete() {
                lock (invokeSyncObject) {
                    this.isCompleted = true;
                    if (this.resetEvent != null) { 
                        this.resetEvent.Set();
                    } 
                } 
            }
        } 

        private class ControlVersionInfo {
            private string companyName = null;
            private string productName = null; 
            private string productVersion = null;
            private FileVersionInfo versionInfo = null; 
            private Control owner; 

            internal ControlVersionInfo(Control owner) { 
                this.owner = owner;
            }

            ///  
            /// 
            ///     The company name associated with the component. 
            ///  
            internal string CompanyName {
                [ResourceExposure(ResourceScope.Machine)] 
                [ResourceConsumption(ResourceScope.Machine)]
                get {
                    if (companyName == null) {
                        object[] attrs = owner.GetType().Module.Assembly.GetCustomAttributes(typeof(AssemblyCompanyAttribute), false); 
                        if (attrs != null && attrs.Length > 0) {
                            companyName = ((AssemblyCompanyAttribute)attrs[0]).Company; 
                        } 

                        if (companyName == null || companyName.Length == 0) { 
                            companyName = GetFileVersionInfo().CompanyName;
                            if (companyName != null) {
                                companyName = companyName.Trim();
                            } 
                        }
 
                        if (companyName == null || companyName.Length == 0) { 
                            string ns = owner.GetType().Namespace;
 
                            if (ns == null) {
                                ns = String.Empty;
                            }
 
                            int firstDot = ns.IndexOf("/");
                            if (firstDot != -1) { 
                                companyName = ns.Substring(0, firstDot); 
                            }
                            else { 
                                companyName = ns;
                            }
                        }
                    } 
                    return companyName;
                } 
            } 

 
            /// 
            /// 
            ///     The product name associated with this component.
            ///  
            internal string ProductName {
                [ResourceExposure(ResourceScope.Machine)] 
                [ResourceConsumption(ResourceScope.Machine)] 
                get {
                    if (productName == null) { 
                        object[] attrs = owner.GetType().Module.Assembly.GetCustomAttributes(typeof(AssemblyProductAttribute), false);
                        if (attrs != null && attrs.Length > 0) {
                            productName = ((AssemblyProductAttribute)attrs[0]).Product;
                        } 

                        if (productName == null || productName.Length == 0) { 
                            productName = GetFileVersionInfo().ProductName; 
                            if (productName != null) {
                                productName = productName.Trim(); 
                            }
                        }

                        if (productName == null || productName.Length == 0) { 
                            string ns = owner.GetType().Namespace;
 
                            if (ns == null) { 
                                ns = String.Empty;
                            } 
                            int firstDot = ns.IndexOf(".");
                            if (firstDot != -1) {
                                productName = ns.Substring(firstDot+1);
                            } 
                            else {
                                productName = ns; 
                            } 
                        }
                    } 

                    return productName;
                }
            } 

 
            ///  
            ///     The product version associated with this component.
            ///  
            internal string ProductVersion {
                [ResourceExposure(ResourceScope.Machine)]
                [ResourceConsumption(ResourceScope.Machine)]
                get { 
                    if (productVersion == null) {
                        // custom attribute 
                        // 
                        object[] attrs = owner.GetType().Module.Assembly.GetCustomAttributes(typeof(AssemblyInformationalVersionAttribute), false);
                        if (attrs != null && attrs.Length > 0) { 
                            productVersion = ((AssemblyInformationalVersionAttribute)attrs[0]).InformationalVersion;
                        }

                        // win32 version info 
                        //
                        if (productVersion == null || productVersion.Length == 0) { 
                            productVersion = GetFileVersionInfo().ProductVersion; 
                            if (productVersion != null) {
                                productVersion = productVersion.Trim(); 
                            }
                        }

                        // fake it 
                        //
                        if (productVersion.Length == 0) { 
                            productVersion = "1.0.0.0"; 
                        }
                    } 
                    return productVersion;
                }
            }
 

            ///  
            ///     Retrieves the FileVersionInfo associated with the main module for 
            ///     the component.
            ///  
            [ResourceExposure(ResourceScope.Machine)]
            [ResourceConsumption(ResourceScope.Machine)]
            private FileVersionInfo GetFileVersionInfo() {
                if (versionInfo == null) { 
                    string path;
 
                    // SECREVIEW : sec assert is safe, the module name is obtained from the system, no user input involded. 
                    //
                    FileIOPermission fiop = new FileIOPermission( PermissionState.None ); 
                    fiop.AllFiles = FileIOPermissionAccess.PathDiscovery;
                    fiop.Assert();
                    try {
                        path = owner.GetType().Module.FullyQualifiedName; 
                    }
                    finally { 
                        CodeAccessPermission.RevertAssert(); 
                    }
 
                    // SECREVIEW : sec assert is safe, the file version is obtained from the system, no user input involded.
                    //
                    new FileIOPermission(FileIOPermissionAccess.Read, path).Assert();
                    try { 
                        versionInfo = FileVersionInfo.GetVersionInfo(path);
                    } 
                    finally { 
                        CodeAccessPermission.RevertAssert();
                    } 
                }

                return versionInfo;
 
            }
 
        } 

        private sealed class MultithreadSafeCallScope : IDisposable 
        {
            // Use local stack variable rather than a refcount since we're
            // guaranteed that these 'scopes' are properly nested.
            private bool resultedInSet; 

            internal MultithreadSafeCallScope() 
            { 
                // Only access the thread-local stuff if we're going to be
                // checking for illegal thread calling (no need to incur the 
                // expense otherwise).
                if (checkForIllegalCrossThreadCalls && !inCrossThreadSafeCall)
                {
                    inCrossThreadSafeCall = true; 
                    resultedInSet = true;
                } 
                else 
                {
                    resultedInSet = false; 
                }
            }

            void IDisposable.Dispose() 
            {
                if (resultedInSet) 
                { 
                    inCrossThreadSafeCall = false;
                } 
            }
        }

        private sealed class PrintPaintEventArgs : PaintEventArgs { 
            Message m;
 
            internal PrintPaintEventArgs(Message m, IntPtr dc, Rectangle clipRect) 
                : base(dc, clipRect) {
                this.m = m; 
            }

            internal Message Message {
                get { 
                    return m;
                } 
            } 
        }
 
    } // end class Control

} // end namespace System.Windows.Forms
 

 
 


// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
#define DEBUG_PREFERREDSIZE 

//------------------------------------------------------------------------------
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved. 
// 
//----------------------------------------------------------------------------- 
 
[assembly: System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Performance", "CA1811:AvoidUncalledPrivateCode", Scope="member", Target="System.Windows.Forms.Control+ActiveXFontMarshaler..ctor()")]
[assembly: System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Security", "CA2122:DoNotIndirectlyExposeMethodsWithLinkDemands", Scope="member", Target="System.Windows.Forms.Control.PreProcessControlMessageInternal(System.Windows.Forms.Control, System.Windows.Forms.Message):System.Windows.Forms.PreProcessControlState")] 
[assembly: System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Security", "CA2122:DoNotIndirectlyExposeMethodsWithLinkDemands", Scope="member", Target="System.Windows.Forms.Control.OnPreviewKeyDown(System.Windows.Forms.PreviewKeyDownEventArgs):System.Void")]

/*
 */ 
namespace System.Windows.Forms {
    using Accessibility; 
    using Microsoft.Win32; 
    using System;
    using System.Collections; 
    using System.Collections.Specialized;
    using System.ComponentModel;
    using System.ComponentModel.Design;
    using System.ComponentModel.Design.Serialization; 
    using System.Configuration.Assemblies;
    using System.Diagnostics; 
    using System.Diagnostics.CodeAnalysis; 
    using System.Drawing;
    using System.Drawing.Drawing2D; 
    using System.Globalization;
    using System.Security.Permissions;
    using System.Security;
    using System.IO; 
    using System.Reflection;
    using System.Runtime.InteropServices; 
    using System.Runtime.InteropServices.ComTypes; 
    using System.Runtime.Remoting;
    using System.Runtime.Serialization; 
    using System.Runtime.Serialization.Formatters;
    using System.Runtime.Serialization.Formatters.Binary;
    using System.Text;
    using System.Threading; 
    using System.Windows.Forms.Design;
    using System.Windows.Forms.Internal; 
    using Encoding = System.Text.Encoding; 
    using System.Drawing.Imaging;
    using System.Windows.Forms.Layout; 
    using System.Runtime.Versioning;

    using IComDataObject = System.Runtime.InteropServices.ComTypes.IDataObject;
 
    /// 
    ///  
    ///    Defines the base class for controls, which are components 
    ///       with visual representation.
    ///  
    [
    ComVisible(true),
    ClassInterface(ClassInterfaceType.AutoDispatch),
    DefaultProperty("Text"), 
    DefaultEvent("Click"),
    Designer("System.Windows.Forms.Design.ControlDesigner, " + AssemblyRef.SystemDesign), 
    DesignerSerializer("System.Windows.Forms.Design.ControlCodeDomSerializer, " + AssemblyRef.SystemDesign, "System.ComponentModel.Design.Serialization.CodeDomSerializer, " + AssemblyRef.SystemDesign), 
    ToolboxItemFilter("System.Windows.Forms")
    ] 
    public partial class Control :
    Component,
    UnsafeNativeMethods.IOleControl,
    UnsafeNativeMethods.IOleObject, 
    UnsafeNativeMethods.IOleInPlaceObject,
    UnsafeNativeMethods.IOleInPlaceActiveObject, 
    UnsafeNativeMethods.IOleWindow, 
    UnsafeNativeMethods.IViewObject,
    UnsafeNativeMethods.IViewObject2, 
    UnsafeNativeMethods.IPersist,
    UnsafeNativeMethods.IPersistStreamInit,
    UnsafeNativeMethods.IPersistPropertyBag,
    UnsafeNativeMethods.IPersistStorage, 
    UnsafeNativeMethods.IQuickActivate,
    ISupportOleDropSource, 
    IDropTarget, 
    ISynchronizeInvoke,
    IWin32Window, 
    IArrangedElement,
    IBindableComponent {

#if FINALIZATION_WATCH 
        static readonly TraceSwitch ControlFinalization = new TraceSwitch("ControlFinalization", "Tracks the creation and destruction of finalization");
        internal static string GetAllocationStack() { 
            if (ControlFinalization.TraceVerbose) { 
                // SECREVIEW: This assert is safe, the operation is safe (data obtained from the CLR). This code is for debugging purposes only.
                // Tracked by VSWhidbey #426446. 
                new EnvironmentPermission(PermissionState.Unrestricted).Assert();
                try {
                    return Environment.StackTrace;
                } 
                    finally {
                        CodeAccessPermission.RevertAssert(); 
                    } 
                }
            else { 
                return "Enable 'ControlFinalization' switch to see stack of allocation";
            }

        } 
        private string allocationSite = Control.GetAllocationStack();
#endif 
 
#if DEBUG
        internal static readonly TraceSwitch PaletteTracing = new TraceSwitch("PaletteTracing", "Debug Palette code"); 
        internal static readonly TraceSwitch ControlKeyboardRouting = new TraceSwitch("ControlKeyboardRouting", "Debug Keyboard routing for controls");
        internal static readonly TraceSwitch FocusTracing = new TraceSwitch("FocusTracing", "Debug focus/active control/enter/leave");
        private static readonly BooleanSwitch AssertOnControlCreateSwitch = new BooleanSwitch("AssertOnControlCreate", "Assert when anything directly deriving from control is created.");
        internal static readonly BooleanSwitch TraceMnemonicProcessing = new BooleanSwitch("TraceCanProcessMnemonic", "Trace mnemonic processing calls to assure right child-parent call ordering."); 

        internal void TraceCanProcessMnemonic(){ 
            if( TraceMnemonicProcessing.Enabled ){ 
            string str;
                try { 
                    str = string.Format( CultureInfo.CurrentCulture, "{0}<{1}>", this.GetType().Name, this.Text );
                    int maxFrameCount = new StackTrace().FrameCount;
                    if (maxFrameCount > 5) {
                        maxFrameCount = 5; 
                    }
                    int frameIndex = 1; 
                    while( frameIndex < maxFrameCount) { 
                        StackFrame sf = new StackFrame(frameIndex);
                        if( frameIndex == 2 && sf.GetMethod().Name.Equals("CanProcessMnemonic") ){ // log immediate call if in a virtual/recursive call. 
                            break;
                        }
                        str += new StackTrace(sf).ToString().TrimEnd();
                        frameIndex++; 
                    }
                    if( frameIndex > 2 ){ // new CanProcessMnemonic virtual/recursive call stack. 
                        str = "\r\n" + str; 
                    }
                } 
                catch (Exception ex) {
                    str = ex.ToString();
                }
                Debug.WriteLine( str ); 
            }
        } 
#else 
        internal static readonly TraceSwitch ControlKeyboardRouting;
        internal static readonly TraceSwitch PaletteTracing; 
        internal static readonly TraceSwitch FocusTracing;
#endif

#if DEBUG 
        internal static readonly BooleanSwitch BufferPinkRect = new BooleanSwitch("BufferPinkRect", "Renders a pink rectangle with painting double buffered controls");
        internal static readonly BooleanSwitch BufferDisabled = new BooleanSwitch("BufferDisabled", "Makes double buffered controls non-double buffered"); 
#else 
        internal static readonly BooleanSwitch BufferPinkRect;
#endif 

        private static int WM_GETCONTROLNAME;
        private static int WM_GETCONTROLTYPE;
 
        static Control() {
            WM_GETCONTROLNAME = SafeNativeMethods.RegisterWindowMessage("WM_GETCONTROLNAME"); 
            WM_GETCONTROLTYPE = SafeNativeMethods.RegisterWindowMessage("WM_GETCONTROLTYPE"); 

        } 

        internal const int STATE_CREATED                = 0x00000001;
        internal const int STATE_VISIBLE                = 0x00000002;
        internal const int STATE_ENABLED                = 0x00000004; 
        internal const int STATE_TABSTOP                = 0x00000008;
        internal const int STATE_RECREATE               = 0x00000010; 
        internal const int STATE_MODAL                  = 0x00000020; 
        internal const int STATE_ALLOWDROP              = 0x00000040;
        internal const int STATE_DROPTARGET             = 0x00000080; 
        internal const int STATE_NOZORDER               = 0x00000100;
        internal const int STATE_LAYOUTDEFERRED         = 0x00000200;
        internal const int STATE_USEWAITCURSOR          = 0x00000400;
        internal const int STATE_DISPOSED               = 0x00000800; 
        internal const int STATE_DISPOSING              = 0x00001000;
        internal const int STATE_MOUSEENTERPENDING      = 0x00002000; 
        internal const int STATE_TRACKINGMOUSEEVENT     = 0x00004000; 
        internal const int STATE_THREADMARSHALLPENDING  = 0x00008000;
        internal const int STATE_SIZELOCKEDBYOS         = 0x00010000; 
        internal const int STATE_CAUSESVALIDATION       = 0x00020000;
        internal const int STATE_CREATINGHANDLE         = 0x00040000;
        internal const int STATE_TOPLEVEL               = 0x00080000;
        internal const int STATE_ISACCESSIBLE           = 0x00100000; 
        internal const int STATE_OWNCTLBRUSH            = 0x00200000;
        internal const int STATE_EXCEPTIONWHILEPAINTING = 0x00400000; 
        internal const int STATE_LAYOUTISDIRTY          = 0x00800000; 
        internal const int STATE_CHECKEDHOST            = 0x01000000;
        internal const int STATE_HOSTEDINDIALOG         = 0x02000000; 
        internal const int STATE_DOUBLECLICKFIRED       = 0x04000000;
        internal const int STATE_MOUSEPRESSED           = 0x08000000;
        internal const int STATE_VALIDATIONCANCELLED    = 0x10000000;
        internal const int STATE_PARENTRECREATING       = 0x20000000; 
        internal const int STATE_MIRRORED               = 0x40000000;
 
        // HACK HACK HACK - when we change RightToLeft, we need to change the scrollbar thumb. 
        // We can't do that until after the control has been created, and all the items added
        // back. This is because the system control won't know the nMin and nMax of the scroll 
        // bar until the items are added. So in RightToLeftChanged, we set a flag that indicates
        // that we want to set the scroll position. In OnHandleCreated we check this flag,
        // and if set, we BeginInvoke. We have to BeginInvoke since we have to wait until the items
        // are added. We only want to do this when RightToLeft changes thus the flags 
        // STATE2_HAVEINVOKED and STATE2_SETSCROLLPOS. Otherwise we would do this on each HandleCreated.
        private  const int STATE2_HAVEINVOKED                       = 0x00000001; 
        private  const int STATE2_SETSCROLLPOS                      = 0x00000002; 
        private  const int STATE2_LISTENINGTOUSERPREFERENCECHANGED  = 0x00000004;   // set when the control is listening to SystemEvents.UserPreferenceChanged.
        internal const int STATE2_INTERESTEDINUSERPREFERENCECHANGED = 0x00000008;   // if set, the control will listen to SystemEvents.UserPreferenceChanged when TopLevel is true and handle is created. 
        internal const int STATE2_MAINTAINSOWNCAPTUREMODE           = 0x00000010;   // if set, the control DOES NOT necessarily take capture on MouseDown
        private  const int STATE2_BECOMINGACTIVECONTROL             = 0x00000020;   // set to true by ContainerControl when this control is becoming its active control

        private  const int STATE2_CLEARLAYOUTARGS                   = 0x00000040;   // if set, the next time PerformLayout is called, cachedLayoutEventArg will be cleared. 
        private  const int STATE2_INPUTKEY                          = 0x00000080;
        private  const int STATE2_INPUTCHAR                         = 0x00000100; 
        private  const int STATE2_UICUES                            = 0x00000200; 
        private  const int STATE2_ISACTIVEX                         = 0x00000400;
        internal const int STATE2_USEPREFERREDSIZECACHE             = 0x00000800; 

        private static readonly object EventAutoSizeChanged           = new object();
        private static readonly object EventKeyDown                   = new object();
        private static readonly object EventKeyPress                  = new object(); 
        private static readonly object EventKeyUp                     = new object();
        private static readonly object EventMouseDown                 = new object(); 
        private static readonly object EventMouseEnter                = new object(); 
        private static readonly object EventMouseLeave                = new object();
        private static readonly object EventMouseHover                = new object(); 
        private static readonly object EventMouseMove                 = new object();
        private static readonly object EventMouseUp                   = new object();
        private static readonly object EventMouseWheel                = new object();
        private static readonly object EventClick                     = new object(); 
        private static readonly object EventClientSize                = new object();
        private static readonly object EventDoubleClick               = new object(); 
        private static readonly object EventMouseClick                = new object(); 
        private static readonly object EventMouseDoubleClick          = new object();
        private static readonly object EventMouseCaptureChanged       = new object(); 
        private static readonly object EventMove                      = new object();
        private static readonly object EventResize                    = new object();
        private static readonly object EventLayout                    = new object();
        private static readonly object EventGotFocus                  = new object(); 
        private static readonly object EventLostFocus                 = new object();
        private static readonly object EventEnabledChanged            = new object(); 
        private static readonly object EventEnter                     = new object(); 
        private static readonly object EventLeave                     = new object();
        private static readonly object EventHandleCreated             = new object(); 
        private static readonly object EventHandleDestroyed           = new object();
        private static readonly object EventVisibleChanged            = new object();
        private static readonly object EventControlAdded              = new object();
        private static readonly object EventControlRemoved            = new object(); 
        private static readonly object EventChangeUICues              = new object();
        private static readonly object EventSystemColorsChanged       = new object(); 
        private static readonly object EventValidating                = new object(); 
        private static readonly object EventValidated                 = new object();
        private static readonly object EventStyleChanged              = new object(); 
        private static readonly object EventImeModeChanged            = new object();
        private static readonly object EventHelpRequested             = new object();
        private static readonly object EventPaint                     = new object();
        private static readonly object EventInvalidated               = new object(); 
        private static readonly object EventQueryContinueDrag         = new object();
        private static readonly object EventGiveFeedback              = new object(); 
        private static readonly object EventDragEnter                 = new object(); 
        private static readonly object EventDragLeave                 = new object();
        private static readonly object EventDragOver                  = new object(); 
        private static readonly object EventDragDrop                  = new object();
        private static readonly object EventQueryAccessibilityHelp    = new object();
        private static readonly object EventBackgroundImage           = new object();
        private static readonly object EventBackgroundImageLayout     = new object(); 
        private static readonly object EventBindingContext            = new object();
        private static readonly object EventBackColor                 = new object(); 
        private static readonly object EventParent                    = new object(); 
        private static readonly object EventVisible                   = new object();
        private static readonly object EventText                      = new object(); 
        private static readonly object EventTabStop                   = new object();
        private static readonly object EventTabIndex                  = new object();
        private static readonly object EventSize                      = new object();
        private static readonly object EventRightToLeft               = new object(); 
        private static readonly object EventLocation                  = new object();
        private static readonly object EventForeColor                 = new object(); 
        private static readonly object EventFont                      = new object(); 
        private static readonly object EventEnabled                   = new object();
        private static readonly object EventDock                      = new object(); 
        private static readonly object EventCursor                    = new object();
        private static readonly object EventContextMenu               = new object();
        private static readonly object EventContextMenuStrip          = new object();
        private static readonly object EventCausesValidation          = new object(); 
        private static readonly object EventRegionChanged             = new object();
        private static readonly object EventMarginChanged             = new object(); 
        internal static readonly object EventPaddingChanged           = new object(); 
        private static readonly object EventPreviewKeyDown            = new object();
 
        #if WIN95_SUPPORT
        private static int mouseWheelMessage = NativeMethods.WM_MOUSEWHEEL;
        private static bool mouseWheelRoutingNeeded;
        private static bool mouseWheelInit; 
        #endif
 
        private static int threadCallbackMessage; 

        // Initially check for illegal multithreading based on whether the 
        // debugger is attached.
        [ResourceExposure(ResourceScope.Process)]
        private static bool checkForIllegalCrossThreadCalls = Debugger.IsAttached;
        private static ContextCallback invokeMarshaledCallbackHelperDelegate; 

        [ ThreadStatic ] 
        private static bool inCrossThreadSafeCall = false; 

// disable csharp compiler warning #0414: field assigned unused value 
#pragma warning disable 0414
        [ ThreadStatic ]
        internal static HelpInfo currentHelpInfo = null;
#pragma warning restore 0414 

        private static FontHandleWrapper defaultFontHandleWrapper; 
 
        private const short PaintLayerBackground = 1;
        private const short PaintLayerForeground = 2; 

        private const byte RequiredScalingEnabledMask = 0x10;
        private const byte RequiredScalingMask = 0x0F;
 
        private static Font defaultFont;
 
        // Property store keys for properties.  The property store allocates most efficiently 
        // in groups of four, so we try to lump properties in groups of four based on how
        // likely they are going to be used in a group. 
        //
        private static readonly int PropName                                = PropertyStore.CreateKey();
        private static readonly int PropBackBrush                           = PropertyStore.CreateKey();
        private static readonly int PropFontHeight                          = PropertyStore.CreateKey(); 
        private static readonly int PropCurrentAmbientFont                  = PropertyStore.CreateKey();
 
        private static readonly int PropControlsCollection                  = PropertyStore.CreateKey(); 
        private static readonly int PropBackColor                           = PropertyStore.CreateKey();
        private static readonly int PropForeColor                           = PropertyStore.CreateKey(); 
        private static readonly int PropFont                                = PropertyStore.CreateKey();

        private static readonly int PropBackgroundImage                     = PropertyStore.CreateKey();
        private static readonly int PropFontHandleWrapper                   = PropertyStore.CreateKey(); 
        private static readonly int PropUserData                            = PropertyStore.CreateKey();
        private static readonly int PropContextMenu                         = PropertyStore.CreateKey(); 
 
        private static readonly int PropCursor                              = PropertyStore.CreateKey();
        private static readonly int PropRegion                              = PropertyStore.CreateKey(); 
        private static readonly int PropRightToLeft                         = PropertyStore.CreateKey();

        private static readonly int PropBindings                            = PropertyStore.CreateKey();
        private static readonly int PropBindingManager                      = PropertyStore.CreateKey(); 
        private static readonly int PropAccessibleDefaultActionDescription  = PropertyStore.CreateKey();
        private static readonly int PropAccessibleDescription               = PropertyStore.CreateKey(); 
 
        private static readonly int PropAccessibility                       = PropertyStore.CreateKey();
        private static readonly int PropNcAccessibility                     = PropertyStore.CreateKey(); 
        private static readonly int PropAccessibleName                      = PropertyStore.CreateKey();
        private static readonly int PropAccessibleRole                      = PropertyStore.CreateKey();

        private static readonly int PropPaintingException                   = PropertyStore.CreateKey(); 
        private static readonly int PropActiveXImpl                         = PropertyStore.CreateKey();
        private static readonly int PropControlVersionInfo                  = PropertyStore.CreateKey(); 
        private static readonly int PropBackgroundImageLayout               = PropertyStore.CreateKey(); 

        private static readonly int PropAccessibleHelpProvider              = PropertyStore.CreateKey(); 
        private static readonly int PropContextMenuStrip                    = PropertyStore.CreateKey();
        private static readonly int PropAutoScrollOffset                    = PropertyStore.CreateKey();
        private static readonly int PropUseCompatibleTextRendering          = PropertyStore.CreateKey();
 
        private static readonly int PropImeWmCharsToIgnore                  = PropertyStore.CreateKey();
        private static readonly int PropImeMode                             = PropertyStore.CreateKey(); 
        private static readonly int PropDisableImeModeChangedCount          = PropertyStore.CreateKey(); 
        private static readonly int PropLastCanEnableIme                    = PropertyStore.CreateKey();
 
        private static readonly int PropCacheTextCount                      = PropertyStore.CreateKey();
        private static readonly int PropCacheTextField                      = PropertyStore.CreateKey();
        private static readonly int PropAmbientPropertiesService            = PropertyStore.CreateKey();
 

        // This switch determines the default text rendering engine to use by some controls that support switching rendering engine. 
        // CheckedListBox, PropertyGrid, GroupBox, Label and LinkLabel, and ButtonBase controls. 
        // True means use GDI+, false means use GDI (TextRenderer).
        internal static bool UseCompatibleTextRenderingDefault = true; 

        ///////////////////////////////////////////////////////////////////////
        // Control per instance members
        // 
        // Note: Do not add anything to this list unless absolutely neccessary.
        //       Every control on a form has the overhead of all of these 
        //       variables! 
        //
        // Begin Members { 

        // List of properties that are generally set, so we keep them directly on
        // control.
        // 

        // Resist the temptation to make this variable 'internal' rather than 
        // private. Handle access should be tightly controlled, and is in this 
        // file.  Making it 'internal' makes controlling it quite difficult.
        private ControlNativeWindow           window; 

        private Control                       parent;
        private Control                       reflectParent;
        private CreateParams                  createParams; 
        private int                           x;                      //
        private int                           y; 
        private int                           width; 
        private int                           height;
        private int                           clientWidth; 
        private int                           clientHeight;
        private int                           state;                  // See STATE_ constants above
        private int                           state2;                 // See STATE2_ constants above
        private ControlStyles                 controlStyle;           // User supplied control style 
        private int                           tabIndex;
        private string                        text;                   // See ControlStyles.CacheText for usage notes 
        private byte                          layoutSuspendCount; 
        private byte                          requiredScaling;        // bits 0-4: BoundsSpecified stored in RequiredScaling property.  Bit 5: RequiredScalingEnabled property.
        private PropertyStore                 propertyStore;          // Contains all properties that are not always set. 
        private NativeMethods.TRACKMOUSEEVENT trackMouseEvent;
        private short                         updateCount;
        private LayoutEventArgs               cachedLayoutEventArgs;
        private Queue                         threadCallbackList; 

        // for keeping track of our ui state for focus and keyboard cues.  using a member variable 
        // here because we hit this a lot 
        //
        private int uiCuesState; 

        private const int UISTATE_FOCUS_CUES_MASK               = 0x000F;
        private const int UISTATE_FOCUS_CUES_HIDDEN             = 0x0001;
        private const int UISTATE_FOCUS_CUES_SHOW               = 0x0002; 
        private const int UISTATE_KEYBOARD_CUES_MASK            = 0x00F0;
        private const int UISTATE_KEYBOARD_CUES_HIDDEN          = 0x0010; 
        private const int UISTATE_KEYBOARD_CUES_SHOW            = 0x0020; 

        // } End Members 
        ///////////////////////////////////////////////////////////////////////

#if DEBUG
        internal int LayoutSuspendCount { 
            get { return layoutSuspendCount; }
        } 
 
        internal void AssertLayoutSuspendCount(int value) {
            Debug.Assert(value == layoutSuspendCount, "Suspend/Resume layout mismatch!"); 
        }

/*
example usage 

#if DEBUG 
        int dbgLayoutCheck = LayoutSuspendCount; 
#endif
#if DEBUG 
        AssertLayoutSuspendCount(dbgLayoutCheck);
#endif
*/
 
#endif
 
        ///  
        /// 
        /// Initializes a new instance of the  class. 
        /// 
        public Control() : this(true) {
        }
 
        /// 
        ///  
        internal Control(bool autoInstallSyncContext) : base() { 
#if DEBUG
            if (AssertOnControlCreateSwitch.Enabled) { 
                Debug.Assert(this.GetType().BaseType != typeof(Control), "Direct derivative of Control Created: " + this.GetType().FullName);
                Debug.Assert(this.GetType() != typeof(Control), "Control Created!");
            }
#endif 
            propertyStore = new PropertyStore();
 
            window = new ControlNativeWindow(this); 
            RequiredScalingEnabled = true;
            RequiredScaling = BoundsSpecified.All; 
            tabIndex = -1;

            state = STATE_VISIBLE | STATE_ENABLED | STATE_TABSTOP | STATE_CAUSESVALIDATION;
            state2 = STATE2_INTERESTEDINUSERPREFERENCECHANGED; 
            SetStyle(ControlStyles.AllPaintingInWmPaint |
                     ControlStyles.UserPaint | 
                     ControlStyles.StandardClick | 
                     ControlStyles.StandardDoubleClick |
                     ControlStyles.UseTextForAccessibility | 
                     ControlStyles.Selectable,true);

#if WIN95_SUPPORT
            InitMouseWheelSupport(); 
#endif
 
            // We baked the "default default" margin and min size into CommonProperties 
            // so that in the common case the PropertyStore would be empty.  If, however,
            // someone overrides these Default* methads, we need to write the default 
            // value into the PropertyStore in the ctor.
            //
            if(DefaultMargin != CommonProperties.DefaultMargin) {
                Margin = DefaultMargin; 
            }
            if(DefaultMinimumSize != CommonProperties.DefaultMinimumSize) { 
                MinimumSize = DefaultMinimumSize; 
            }
            if(DefaultMaximumSize != CommonProperties.DefaultMaximumSize) { 
                MaximumSize = DefaultMaximumSize;
            }

            // Compute our default size. 
            //
            Size defaultSize = DefaultSize; 
            width = defaultSize.Width; 
            height = defaultSize.Height;
 
            // DefaultSize may have hit GetPreferredSize causing a PreferredSize to be cached.  The
            // PreferredSize may change as a result of the current size.  Since a  SetBoundsCore did
            // not happen, so we need to clear the preferredSize cache manually.
            CommonProperties.xClearPreferredSizeCache(this); 

            if (width != 0 && height != 0) { 
                NativeMethods.RECT rect = new NativeMethods.RECT(); 
                rect.left = rect.right = rect.top = rect.bottom = 0;
 
                CreateParams cp = CreateParams;

                SafeNativeMethods.AdjustWindowRectEx(ref rect, cp.Style, false, cp.ExStyle);
                clientWidth = width - (rect.right - rect.left); 
                clientHeight = height - (rect.bottom - rect.top);
            } 
 

            // Set up for async operations on this thread. 
            if (autoInstallSyncContext) {
                WindowsFormsSynchronizationContext.InstallIfNeeded();
            }
        } 

        ///  
        ///  
        /// Initializes a new instance of the  class.
        ///  
        public Control( string text ) : this( (Control) null, text ) {
        }

        ///  
        /// 
        /// Initializes a new instance of the  class. 
        ///  
        public Control( string text, int left, int top, int width, int height ) :
                    this( (Control) null, text, left, top, width, height ) { 
        }

        /// 
        ///  
        /// Initializes a new instance of the  class.
        ///  
        public Control( Control parent, string text ) : this() { 
            this.Parent = parent;
            this.Text = text; 
        }

        /// 
        ///  
        /// Initializes a new instance of the  class.
        ///  
        public Control( Control parent, string text, int left, int top, int width, int height ) : this( parent, text ) { 
            this.Location = new Point( left, top );
            this.Size = new Size( width, height ); 
        }

        /// 
        ///  
        ///      The Accessibility Object for this Control
        ///  
        [ 
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden), 
        SRDescription(SR.ControlAccessibilityObjectDescr)
        ]
        public AccessibleObject AccessibilityObject {
            get { 
                AccessibleObject accessibleObject = (AccessibleObject)Properties.GetObject(PropAccessibility);
                if (accessibleObject == null) { 
                    accessibleObject = CreateAccessibilityInstance(); 
                    // this is a security check. we want to enforce that we only return
                    // ControlAccessibleObject and not some other derived class 
                    if(!(accessibleObject is ControlAccessibleObject)) {
                        Debug.Fail("Accessible objects for controls must be derived from ControlAccessibleObject.");
                        return null;
                    } 
                    Properties.SetObject(PropAccessibility, accessibleObject);
                } 
 
                Debug.Assert(accessibleObject != null, "Failed to create accessibility object");
                return accessibleObject; 
            }
        }

        ///  
        ///      Private accessibility object for control, used to wrap the object that
        ///      OLEACC.DLL creates to represent the control's non-client (NC) region. 
        ///  
        private AccessibleObject NcAccessibilityObject {
            get { 
                AccessibleObject ncAccessibleObject = (AccessibleObject)Properties.GetObject(PropNcAccessibility);
                if (ncAccessibleObject == null) {
                    ncAccessibleObject = new ControlAccessibleObject(this, NativeMethods.OBJID_WINDOW);
                    Properties.SetObject(PropNcAccessibility, ncAccessibleObject); 
                }
 
                Debug.Assert(ncAccessibleObject != null, "Failed to create NON-CLIENT accessibility object"); 
                return ncAccessibleObject;
            } 
        }

        /// 
        ///     Returns a specific AccessibleObject associated with this 
        ///     control, based on standard "accessibile object id".
        ///  
        ///  
        private AccessibleObject GetAccessibilityObject(int accObjId) {
            AccessibleObject accessibleObject; 

            switch (accObjId) {
                case NativeMethods.OBJID_CLIENT:
                    accessibleObject = this.AccessibilityObject; 
                    break;
                case NativeMethods.OBJID_WINDOW: 
                    accessibleObject = this.NcAccessibilityObject; 
                    break;
                default: 
                    if (accObjId > 0) {
                        accessibleObject = this.GetAccessibilityObjectById(accObjId);
                    } else {
                        accessibleObject = null; 
                    }
                    break; 
            } 

            return accessibleObject; 
        }

        /// 
        ///  
        ///      Returns a specific AccessibleObbject associated w/ the objectID
        ///  
        protected virtual AccessibleObject GetAccessibilityObjectById(int objectId) { 
            return null;
        } 

        /// 
        /// 
        ///      The default action description of the control 
        /// 
        [ 
        SRCategory(SR.CatAccessibility), 
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden), 
        SRDescription(SR.ControlAccessibleDefaultActionDescr)
        ]
        public string AccessibleDefaultActionDescription {
            get { 
                return (string)Properties.GetObject(PropAccessibleDefaultActionDescription);
            } 
            set { 
                Properties.SetObject(PropAccessibleDefaultActionDescription, value);
            } 
        }

        /// 
        ///  
        ///      The accessible description of the control
        ///  
        [ 
        SRCategory(SR.CatAccessibility),
        DefaultValue(null), 
        Localizable(true),
        SRDescription(SR.ControlAccessibleDescriptionDescr)
        ]
        public string AccessibleDescription { 
            get {
                return (string)Properties.GetObject(PropAccessibleDescription); 
            } 
            set {
                Properties.SetObject(PropAccessibleDescription, value); 
            }
        }

        ///  
        /// 
        ///      The accessible name of the control 
        ///  
        [
        SRCategory(SR.CatAccessibility), 
        DefaultValue(null),
        Localizable(true),
        SRDescription(SR.ControlAccessibleNameDescr)
        ] 
        public string AccessibleName {
            get { 
                return (string)Properties.GetObject(PropAccessibleName); 
            }
 
            set {
                Properties.SetObject(PropAccessibleName, value);
            }
        } 

        ///  
        ///  
        ///      The accessible role of the control
        ///  
        [
        SRCategory(SR.CatAccessibility),
        DefaultValue(AccessibleRole.Default),
        SRDescription(SR.ControlAccessibleRoleDescr) 
        ]
        public AccessibleRole AccessibleRole { 
 
            get {
                bool found; 
                int role = Properties.GetInteger(PropAccessibleRole, out found);
                if (found) {
                    return (AccessibleRole)role;
                } 
                else {
                    return AccessibleRole.Default; 
                } 
            }
 
            set {
                //valid values are -1 to 0x40
                if (!ClientUtils.IsEnumValid(value, (int)value, (int)AccessibleRole.Default, (int)AccessibleRole.OutlineButton)) {
                    throw new InvalidEnumArgumentException("value", (int)value, typeof(AccessibleRole)); 
                }
                Properties.SetInteger(PropAccessibleRole, (int)value); 
            } 
        }
 
        /// 
        ///     Helper method for retrieving an ActiveX property.  We abstract these
        ///     to another method so we do not force JIT the ActiveX codebase.
        ///  
        private Color ActiveXAmbientBackColor {
            get { 
                return ActiveXInstance.AmbientBackColor; 
            }
        } 

        /// 
        ///     Helper method for retrieving an ActiveX property.  We abstract these
        ///     to another method so we do not force JIT the ActiveX codebase. 
        /// 
        private Color ActiveXAmbientForeColor { 
            get { 
                return ActiveXInstance.AmbientForeColor;
            } 
        }

        /// 
        ///     Helper method for retrieving an ActiveX property.  We abstract these 
        ///     to another method so we do not force JIT the ActiveX codebase.
        ///  
        private Font ActiveXAmbientFont { 
            [ResourceExposure(ResourceScope.Process)]
            [ResourceConsumption(ResourceScope.Process)] 
            get {
                return ActiveXInstance.AmbientFont;
            }
        } 

        ///  
        ///     Helper method for retrieving an ActiveX property.  We abstract these 
        ///     to another method so we do not force JIT the ActiveX codebase.
        ///  
        private bool ActiveXEventsFrozen {
            get {
                return ActiveXInstance.EventsFrozen;
            } 
        }
 
        ///  
        ///     Helper method for retrieving an ActiveX property.  We abstract these
        ///     to another method so we do not force JIT the ActiveX codebase. 
        /// 
        private IntPtr ActiveXHWNDParent {
            get {
                return ActiveXInstance.HWNDParent; 
            }
        } 
 
        /// 
        ///      Retrieves the ActiveX control implementation for 
        ///      this control.  This will demand create the implementation
        ///      if it does not already exist.
        /// 
        private ActiveXImpl ActiveXInstance { 
            get {
                ActiveXImpl activeXImpl = (ActiveXImpl)Properties.GetObject(PropActiveXImpl); 
                if (activeXImpl == null) { 

                    // Don't allow top level objects to be hosted 
                    // as activeX controls.
                    //
                    if (GetState(STATE_TOPLEVEL)) {
                        throw new NotSupportedException(SR.GetString(SR.AXTopLevelSource)); 
                    }
 
                    activeXImpl = new ActiveXImpl(this); 

                    // PERF: IsActiveX is called quite a bit - checked everywhere from sizing to event raising.  Using a state 
                    // bit to track PropActiveXImpl instead of fetching from the property store.
                    SetState2(STATE2_ISACTIVEX, true);
                    Properties.SetObject(PropActiveXImpl, activeXImpl);
                } 

                return activeXImpl; 
            } 
        }
 
        /// 
        /// 
        ///     The AllowDrop property. If AllowDrop is set to true then
        ///     this control will allow drag and drop operations and events to be used. 
        /// 
        [ 
        SRCategory(SR.CatBehavior), 
        DefaultValue(false),
        SRDescription(SR.ControlAllowDropDescr) 
        ]
        public virtual bool AllowDrop {
            get {
                return GetState(STATE_ALLOWDROP); 
            }
 
            set { 
                if (GetState(STATE_ALLOWDROP) != value) {
                    // Since we won't call SetAcceptDrops without a handle, 
                    // we do the security demand here. Without this demand
                    // we are still safe, but you get the exception at an
                    // odd time. This gives a better experience.
                    // 
                    if (value && !IsHandleCreated) {
                        IntSecurity.ClipboardRead.Demand(); 
                    } 

                    SetState(STATE_ALLOWDROP, value); 

                    if (IsHandleCreated) {
                        try {
                            SetAcceptDrops(value); 
                        }
                        catch { 
                            // If there is an error, back out the AllowDrop state... 
                            //
                            SetState(STATE_ALLOWDROP, !value); 
                            throw;
                        }
                    }
                } 
            }
        } 
 
        // Queries the Site for AmbientProperties.  May return null.
        // Do not confuse with inheritedProperties -- the service is turned to 
        // after we've exhausted inheritedProperties.
        private AmbientProperties AmbientPropertiesService {
            get {
                bool contains; 
                AmbientProperties props = (AmbientProperties)Properties.GetObject(PropAmbientPropertiesService, out contains);
                if (!contains) { 
                    if (Site != null) { 
                        props = (AmbientProperties)Site.GetService(typeof(AmbientProperties));
                    } 
                    else {
                        props = (AmbientProperties)GetService(typeof(AmbientProperties));
                    }
 
                    if (props != null) {
                        Properties.SetObject(PropAmbientPropertiesService, props); 
                    } 
                }
                return props; 
            }
        }

        ///  
        /// 
        ///     The current value of the anchor property. The anchor property 
        ///     determines which edges of the control are anchored to the container's 
        ///     edges.
        ///  
        [
        SRCategory(SR.CatLayout),
        Localizable(true),
        DefaultValue(CommonProperties.DefaultAnchor), 
        SRDescription(SR.ControlAnchorDescr),
        RefreshProperties(RefreshProperties.Repaint) 
        ] 
        public virtual AnchorStyles Anchor {
            get { 
                return DefaultLayout.GetAnchor(this);
            }
            set {
                DefaultLayout.SetAnchor(ParentInternal, this, value); 
            }
        } 
 
        /// 
        [SRCategory(SR.CatLayout)] 
        [RefreshProperties(RefreshProperties.All)]
        [Localizable(true)]
        [DefaultValue(CommonProperties.DefaultAutoSize)]
        [SRDescription(SR.ControlAutoSizeDescr)] 
        [Browsable(false), EditorBrowsable(EditorBrowsableState.Never),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)] 
        public virtual bool AutoSize { 
            get { return CommonProperties.GetAutoSize(this); }
            set { 
                if(value != AutoSize) {
                    CommonProperties.SetAutoSize(this, value);
                    if(ParentInternal != null) {
                        // DefaultLayout does not keep anchor information until it needs to.  When 
                        // AutoSize became a common property, we could no longer blindly call into
                        // DefaultLayout, so now we do a special InitLayout just for DefaultLayout. 
                        if(value && ParentInternal.LayoutEngine == DefaultLayout.Instance) { 
                            ParentInternal.LayoutEngine.InitLayout(this, BoundsSpecified.Size);
                        } 
                        LayoutTransaction.DoLayout(ParentInternal, this, PropertyNames.AutoSize);
                    }

                    OnAutoSizeChanged(EventArgs.Empty); 
                }
            } 
        } 

 
        /// 
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlOnAutoSizeChangedDescr)]
        [Browsable(false), EditorBrowsable(EditorBrowsableState.Never)]
        public event EventHandler AutoSizeChanged { 
            add {
                Events.AddHandler(EventAutoSizeChanged, value); 
            } 
            remove {
                Events.RemoveHandler(EventAutoSizeChanged, value); 
            }
        }

        ///  
        /// Controls the location of where this control is scrolled to in ScrollableControl.ScrollControlIntoView.
        /// Default is the upper left hand corner of the control. 
        ///  
        [
        Browsable(false), 
        EditorBrowsable(EditorBrowsableState.Advanced),
        DefaultValue(typeof(Point), "0, 0")
        ]
        public virtual Point AutoScrollOffset { 
            get {
                if (Properties.ContainsObject(PropAutoScrollOffset)) { 
                    return (Point)Properties.GetObject(PropAutoScrollOffset); 
                }
                return Point.Empty; 
            }
            set {
                if (AutoScrollOffset != value) {
                    Properties.SetObject(PropAutoScrollOffset, value); 
                }
            } 
        } 

        protected void SetAutoSizeMode(AutoSizeMode mode) { 
            CommonProperties.SetAutoSizeMode(this, mode);
        }

        protected AutoSizeMode GetAutoSizeMode() { 
            return CommonProperties.GetAutoSizeMode(this);
        } 
 
        /// 
        // Public because this is interesting for ControlDesigners. 
        [Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced)]
        public virtual LayoutEngine LayoutEngine {
            [System.Runtime.TargetedPatchingOptOutAttribute("Performance critical to inline across NGen image boundaries")]
            get { return DefaultLayout.Instance; } 
        }
 
        ///  
        ///     The GDI brush for our background color.
        ///     Whidbey Note: Made this internal, since we need to use this in ButtonStandardAdapter. Also, renamed 
        ///                   from BackBrush to BackColorBrush due to a naming conflict with DataGrid's BackBrush.
        /// 
        internal IntPtr BackColorBrush {
            [ResourceExposure(ResourceScope.Process)] 
            [ResourceConsumption(ResourceScope.Process)]
            get { 
                object customBackBrush = Properties.GetObject(PropBackBrush); 
                if (customBackBrush != null) {
 
                    // We already have a valid brush.  Unbox, and return.
                    //
                    return (IntPtr)customBackBrush;
                } 

                if (!Properties.ContainsObject(PropBackColor)) { 
 
                    // No custom back color.  See if we can get to our parent.
                    // The color check here is to account for parents and children who 
                    // override the BackColor property.
                    //
                    if (parent != null && parent.BackColor == BackColor) {
                        return parent.BackColorBrush; 
                    }
                } 
 
                // No parent, or we have a custom back color.  Either way, we need to
                // create our own. 
                //
                Color color = BackColor;
                IntPtr backBrush;
 
                if (ColorTranslator.ToOle(color) < 0) {
                    backBrush = SafeNativeMethods.GetSysColorBrush(ColorTranslator.ToOle(color) & 0xFF); 
                    SetState(STATE_OWNCTLBRUSH, false); 
                }
                else { 
                    backBrush = SafeNativeMethods.CreateSolidBrush(ColorTranslator.ToWin32(color));
                    SetState(STATE_OWNCTLBRUSH, true);
                }
 
                Debug.Assert(backBrush != IntPtr.Zero, "Failed to create brushHandle");
                Properties.SetObject(PropBackBrush, backBrush); 
 
                return backBrush;
            } 
        }

        /// 
        ///  
        ///     The background color of this control. This is an ambient property and
        ///     will always return a non-null value. 
        ///  
        [
        SRCategory(SR.CatAppearance), 
        DispId(NativeMethods.ActiveX.DISPID_BACKCOLOR),
        SRDescription(SR.ControlBackColorDescr)
        ]
        public virtual Color BackColor { 
            get {
                Color c = RawBackColor; // inheritedProperties.BackColor 
                if (!c.IsEmpty) { 
                    return c;
                } 

                Control p = ParentInternal;
                if (p != null && p.CanAccessProperties) {
                    c = p.BackColor; 
                    if (IsValidBackColor(c))
                    { 
                        return c; 
                    }
 
                }

                if (IsActiveX) {
                    c = ActiveXAmbientBackColor; 
                }
 
                if (c.IsEmpty) { 
                    AmbientProperties ambient = AmbientPropertiesService;
                    if (ambient != null) 
                        c = ambient.BackColor;
                }

                if (!c.IsEmpty && IsValidBackColor(c)) 
                    return c;
                else 
                    return DefaultBackColor; 
            }
 
            set {
                if (!value.Equals(Color.Empty) && !GetStyle(ControlStyles.SupportsTransparentBackColor) && value.A < 255)
                    throw new ArgumentException(SR.GetString(SR.TransparentBackColorNotAllowed));
 
                Color c = BackColor;
                if (!value.IsEmpty || Properties.ContainsObject(PropBackColor)) { 
                    Properties.SetColor(PropBackColor, value); 
                }
 
                if (!c.Equals(BackColor)) {
                    OnBackColorChanged(EventArgs.Empty);
                }
            } 
        }
 
        ///  
        /// 
        ///    [To be supplied.] 
        /// 
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlOnBackColorChangedDescr)]
        public event EventHandler BackColorChanged {
            add { 
                Events.AddHandler(EventBackColor, value);
            } 
            remove { 
                Events.RemoveHandler(EventBackColor, value);
            } 
        }

        /// 
        ///  
        ///     The background image of the control.
        ///  
        [ 
        SRCategory(SR.CatAppearance),
        DefaultValue(null), 
        Localizable(true),
        SRDescription(SR.ControlBackgroundImageDescr)
        ]
        public virtual Image BackgroundImage { 
            get {
                return (Image)Properties.GetObject(PropBackgroundImage); 
            } 
            set {
                if (BackgroundImage != value) { 
                    Properties.SetObject(PropBackgroundImage, value);
                    OnBackgroundImageChanged(EventArgs.Empty);
                }
            } 
        }
 
        ///  
        /// 
        ///    [To be supplied.] 
        /// 
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlOnBackgroundImageChangedDescr)]
        public event EventHandler BackgroundImageChanged {
            add { 
                Events.AddHandler(EventBackgroundImage, value);
            } 
            remove { 
                Events.RemoveHandler(EventBackgroundImage, value);
            } 
        }

        /// 
        ///  
        ///     The BackgroundImageLayout of the control.
        ///  
        [ 
        SRCategory(SR.CatAppearance),
        DefaultValue(ImageLayout.Tile), 
        Localizable(true),
        SRDescription(SR.ControlBackgroundImageLayoutDescr)
        ]
        public virtual ImageLayout BackgroundImageLayout { 
            get {
                bool found = Properties.ContainsObject(PropBackgroundImageLayout); 
                if (!found) { 
                    return ImageLayout.Tile;
                } 
                else {
                    return ((ImageLayout)Properties.GetObject(PropBackgroundImageLayout));
               }
            } 
            set {
                if (BackgroundImageLayout != value) { 
                    //valid values are 0x0 to 0x4 
                    if (!ClientUtils.IsEnumValid(value, (int)value, (int)ImageLayout.None, (int)ImageLayout.Zoom)){
                        throw new InvalidEnumArgumentException("value", (int)value, typeof(ImageLayout)); 
                    }
                    // Check if the value is either center, strech or zoom;
                    if (value == ImageLayout.Center || value == ImageLayout.Zoom || value == ImageLayout.Stretch) {
                        SetStyle(ControlStyles.ResizeRedraw, true); 
                        // Only for images that support transparency.
                        if (ControlPaint.IsImageTransparent(BackgroundImage)) 
                        { 
                            DoubleBuffered = true;
                        } 
                    }
                    Properties.SetObject(PropBackgroundImageLayout, value);
                    OnBackgroundImageLayoutChanged(EventArgs.Empty);
                } 
            }
        } 
 
        /// 
        ///  
        ///    [To be supplied.]
        /// 
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlOnBackgroundImageLayoutChangedDescr)]
        public event EventHandler BackgroundImageLayoutChanged { 
            add {
                Events.AddHandler(EventBackgroundImageLayout, value); 
            } 
            remove {
                Events.RemoveHandler(EventBackgroundImageLayout, value); 
            }
        }

        // Set/reset by ContainerControl.AssignActiveControlInternal 
        internal bool BecomingActiveControl
        { 
            get 
            {
                return GetState2(STATE2_BECOMINGACTIVECONTROL); 
            }
            set
            {
                if (value != this.BecomingActiveControl) 
                {
                    Application.ThreadContext.FromCurrent().ActivatingControl = (value) ? this : null; 
                    SetState2(STATE2_BECOMINGACTIVECONTROL, value); 
                }
            } 
        }

        private bool ShouldSerializeAccessibleName() {
            string accName = this.AccessibleName; 
            return accName != null && accName.Length > 0;
        } 
 
        /// 
        ///  
        ///    [To be supplied.]
        /// 
        [EditorBrowsable(EditorBrowsableState.Never)]
        public void ResetBindings() { 
            ControlBindingsCollection bindings = (ControlBindingsCollection)Properties.GetObject(PropBindings);
            if (bindings != null) { 
                bindings.Clear(); 
            }
        } 

        /// 
        /// 
        ///    BindingContextInternal provides a mechanism so that controls like SplitContainer that inherit from the 
        ///    ContainerControl can bypass the "containerControls" bindingContext property and do what the other simple controls
        ///    do. 
        ///  
        internal BindingContext BindingContextInternal
        { 
            get
            {
                // See if we have locally overridden the binding manager.
                // 
                BindingContext context = (BindingContext) Properties.GetObject(PropBindingManager);
                if (context != null) { 
                    return context; 
                }
 
                // Otherwise, see if the parent has one for us.
                //
                Control p = ParentInternal;
                if (p != null && p.CanAccessProperties) { 
                    return p.BindingContext;
                } 
 
                // Otherwise, we have no binding manager available.
                // 
                return null;
            }
            set
            { 
                BindingContext oldContext = (BindingContext) Properties.GetObject(PropBindingManager);
                BindingContext newContext = value; 
 
                if (oldContext != newContext) {
                    Properties.SetObject(PropBindingManager, newContext); 

                    // the property change will wire up the bindings.
                    //
                    OnBindingContextChanged(EventArgs.Empty); 
                }
            } 
        } 

        ///  
        /// 
        ///    [To be supplied.]
        /// 
        [ 
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden), 
        SRDescription(SR.ControlBindingContextDescr) 
        ]
        public virtual BindingContext BindingContext { 
            get {
                return BindingContextInternal;
            }
            set { 
                BindingContextInternal = value;
            } 
        } 

        ///  
        /// 
        ///    [To be supplied.]
        /// 
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlOnBindingContextChangedDescr)] 
        public event EventHandler BindingContextChanged {
            add { 
                Events.AddHandler(EventBindingContext, value); 
            }
            remove { 
                Events.RemoveHandler(EventBindingContext, value);
            }
        }
 
        /// 
        ///  
        ///    The bottom coordinate of this control. 
        /// 
        [ 
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        SRDescription(SR.ControlBottomDescr),
        SRCategory(SR.CatLayout) 
        ]
        public int Bottom { 
            get { 
                return y + height;
            } 
        }

        /// 
        ///  
        ///     The bounds of this control. This is the window coordinates of the
        ///     control in parent client coordinates. 
        ///  
        [
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        SRDescription(SR.ControlBoundsDescr),
        SRCategory(SR.CatLayout)
        ] 
        public Rectangle Bounds {
            get { 
                return new Rectangle(x, y, width, height); 
            }
 
            set {
                SetBounds(value.X, value.Y, value.Width, value.Height, BoundsSpecified.All);
            }
        } 

        ///  
        ///  
        /// 
        internal virtual bool CanAccessProperties { 
            get {
                return true;
            }
        } 

        ///  
        ///  
        ///    Indicates whether the control can receive focus. This
        ///       property is read-only. 
        /// 
        [
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden), 
        SRCategory(SR.CatFocus),
        SRDescription(SR.ControlCanFocusDescr) 
        ] 
        public bool CanFocus {
            get { 
                if (!IsHandleCreated) {
                    return false;
                }
                bool visible = SafeNativeMethods.IsWindowVisible(new HandleRef(window, Handle)); 
                bool enabled = SafeNativeMethods.IsWindowEnabled(new HandleRef(window, Handle));
                return (visible && enabled); 
            } 
        }
 
        /// 
        /// 
        ///     Determines if events can be fired on the control.  If this control is being
        ///     hosted as an ActiveX control, this property will return false if the ActiveX 
        ///     control has its events frozen.
        ///  
        protected override bool CanRaiseEvents { 
            [System.Runtime.TargetedPatchingOptOutAttribute("Performance critical to inline across NGen image boundaries")]
            get { 
                if (IsActiveX) {
                    return !ActiveXEventsFrozen;
                }
 
                return true;
            } 
        } 

        ///  
        /// 
        ///    
        ///       Indicates whether the control can be selected. This property
        ///       is read-only. 
        /// 
        [ 
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        SRCategory(SR.CatFocus), 
        SRDescription(SR.ControlCanSelectDescr)
        ]
        public bool CanSelect {
            // We implement this to allow only AxHost to override canSelectCore, but still 
            // expose the method publicly
            // 
            get { 
                return CanSelectCore();
            } 
        }

        /// 
        ///  
        ///     Indicates whether the control has captured the mouse.
        ///  
        [ 
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden), 
        SRCategory(SR.CatFocus),
        SRDescription(SR.ControlCaptureDescr)
        ]
        public bool Capture { 
            [System.Runtime.TargetedPatchingOptOutAttribute("Performance critical to inline across NGen image boundaries")]
            get { 
                return CaptureInternal; 
            }
 
            set {
                if (value) {
                    Debug.WriteLineIf(IntSecurity.SecurityDemand.TraceVerbose, "GetCapture Demanded");
                    IntSecurity.GetCapture.Demand(); 
                }
                CaptureInternal = value; 
            } 
        }
 
        // SECURITY WARNING: This property bypasses a security demand. Use with caution!
        internal bool CaptureInternal {
            [System.Runtime.TargetedPatchingOptOutAttribute("Performance critical to inline across NGen image boundaries")]
            get { 
                return IsHandleCreated && UnsafeNativeMethods.GetCapture() == Handle;
            } 
            set { 
                if (CaptureInternal != value) {
                    if (value) { 
                        UnsafeNativeMethods.SetCapture(new HandleRef(this, Handle));
                    }
                    else {
                        SafeNativeMethods.ReleaseCapture(); 
                    }
                } 
            } 
        }
 
        /// 
        /// 
        ///    
        ///       Indicates whether entering the control causes validation on the controls requiring validation. 
        /// 
        [ 
        SRCategory(SR.CatFocus), 
        DefaultValue(true),
        SRDescription(SR.ControlCausesValidationDescr) 
        ]
        public bool CausesValidation {
            get {
                return GetState(STATE_CAUSESVALIDATION); 
            }
            set { 
                if (value != this.CausesValidation) { 
                    SetState(STATE_CAUSESVALIDATION, value);
                    OnCausesValidationChanged(EventArgs.Empty); 
                }
            }
        }
 

        ///  
        ///  
        ///    [To be supplied.]
        ///  
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlOnCausesValidationChangedDescr)]
        public event EventHandler CausesValidationChanged {
            add {
                Events.AddHandler(EventCausesValidation, value); 
            }
            remove { 
                Events.RemoveHandler(EventCausesValidation, value); 
            }
        } 


        /// This is for perf. Turn this property on to temporarily enable text caching.  This is good for
        /// operations such as layout or painting where we don't expect the text to change (we will update the 
        /// cache if it does) but prevents us from sending a ton of messages turing layout.  See the PaintWithErrorHandling
        /// function. 
        /// 
        internal bool CacheTextInternal {
            get { 

                // check if we're caching text.
                //
                bool found; 
                int cacheTextCounter = Properties.GetInteger(PropCacheTextCount, out found);
 
                return cacheTextCounter > 0 || GetStyle(ControlStyles.CacheText); 
            }
            set { 

                // if this control always cachest text or the handle hasn't been created,
                // just bail.
                // 
                if (GetStyle(ControlStyles.CacheText) || !IsHandleCreated) {
                    return; 
                } 

                // otherwise, get the state and update the cache if necessary. 
                //
                bool found;
                int cacheTextCounter = Properties.GetInteger(PropCacheTextCount, out found);
 
                if (value) {
                    if (cacheTextCounter == 0) { 
                        Properties.SetObject(PropCacheTextField, text); 
                        if (text == null)  {
                            text = WindowText; 
                        }
                    }
                    cacheTextCounter++;
                } 
                else {
                    cacheTextCounter--; 
                    if (cacheTextCounter == 0) { 
                        text = (string)Properties.GetObject(PropCacheTextField, out found);
                    } 
                }
                Properties.SetInteger(PropCacheTextCount, cacheTextCounter);
            }
        } 

 
        ///  
        [ Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced),
          SRDescription(SR.ControlCheckForIllegalCrossThreadCalls), 
          DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        ]
        public static bool CheckForIllegalCrossThreadCalls {
            get { return checkForIllegalCrossThreadCalls; } 
            set { checkForIllegalCrossThreadCalls = value; }
        } 
 
        /// 
        ///  
        ///     The client rect of the control.
        /// 
        [
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        SRCategory(SR.CatLayout), 
        SRDescription(SR.ControlClientRectangleDescr) 
        ]
        public Rectangle ClientRectangle { 
            get {
                return new Rectangle(0, 0, clientWidth, clientHeight);
            }
        } 

        ///  
        ///  
        ///     The size of the clientRect.
        ///  
        [
        SRCategory(SR.CatLayout),
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden), 
        SRDescription(SR.ControlClientSizeDescr)
        ] 
        public Size ClientSize { 
            get {
                return new Size(clientWidth, clientHeight); 
            }

            set {
                SetClientSizeCore(value.Width, value.Height); 
            }
        } 
 
        /// 
        ///  
        ///    Fired when ClientSize changes.
        /// 
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlOnClientSizeChangedDescr)]
        public event EventHandler ClientSizeChanged { 
            add {
                Events.AddHandler(EventClientSize, value); 
            } 
            remove {
                Events.RemoveHandler(EventClientSize, value); 
            }
        }

        ///  
        /// 
        ///     Retrieves the company name of this specific component. 
        ///  
        [
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        DescriptionAttribute(SR.ControlCompanyNameDescr)
        ]
        public string CompanyName { 
            [ResourceExposure(ResourceScope.Machine)]
            [ResourceConsumption(ResourceScope.Machine)] 
            get { 
                return VersionInfo.CompanyName;
            } 
        }

        /// 
        ///  
        ///    Indicates whether the control or one of its children currently has the system
        ///       focus. This property is read-only. 
        ///  
        [
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        SRDescription(SR.ControlContainsFocusDescr)
        ]
        public bool ContainsFocus { 
            get {
                if (!IsHandleCreated) { 
                    return false; 
                }
 
                IntPtr focusHwnd = UnsafeNativeMethods.GetFocus();

                if (focusHwnd == IntPtr.Zero) {
                    return false; 
                }
 
                if (focusHwnd == this.Handle) { 
                    return true;
                } 

                if (UnsafeNativeMethods.IsChild(new HandleRef(this, this.Handle), new HandleRef(this, focusHwnd))) {
                    return true;
                } 

                return false; 
            } 
        }
 
        /// 
        /// 
        ///     The contextMenu associated with this control. The contextMenu
        ///     will be shown when the user right clicks the mouse on the control. 
        ///
        ///     Whidbey: ContextMenu is browsable false.  In all cases where both a context menu 
        ///     and a context menu strip are assigned, context menu will be shown instead of context menu strip. 
        /// 
        [ 
        SRCategory(SR.CatBehavior),
        DefaultValue(null),
        SRDescription(SR.ControlContextMenuDescr),
        Browsable(false) 
        ]
        public virtual ContextMenu ContextMenu { 
            get { 
                return (ContextMenu)Properties.GetObject(PropContextMenu);
            } 
            set {
                ContextMenu oldValue = (ContextMenu)Properties.GetObject(PropContextMenu);

                if (oldValue != value) { 
                    EventHandler disposedHandler = new EventHandler(DetachContextMenu);
 
                    if (oldValue != null) { 
                        oldValue.Disposed -= disposedHandler;
                    } 

                    Properties.SetObject(PropContextMenu, value);

                    if (value != null) { 
                        value.Disposed += disposedHandler;
                    } 
 
                    OnContextMenuChanged(EventArgs.Empty);
                } 
            }
        }

        ///  
        /// 
        ///    [To be supplied.] 
        ///  
        [
        SRCategory(SR.CatPropertyChanged), 
        SRDescription(SR.ControlOnContextMenuChangedDescr),
        Browsable(false)
        ]
        public event EventHandler ContextMenuChanged { 
            add {
                Events.AddHandler(EventContextMenu, value); 
            } 
            remove {
                Events.RemoveHandler(EventContextMenu, value); 
            }
        }

 
       /// 
       ///  
       ///     The contextMenuStrip associated with this control. The contextMenuStrip 
       ///     will be shown when the user right clicks the mouse on the control.
       ///     Note: if a context menu is also assigned, it will take precidence over this property. 
       /// 
        [
        SRCategory(SR.CatBehavior),
        DefaultValue(null), 
        SRDescription(SR.ControlContextMenuDescr)
        ] 
        public virtual ContextMenuStrip ContextMenuStrip { 
            get {
                 return (ContextMenuStrip)Properties.GetObject(PropContextMenuStrip); 
             }
             set {
                 ContextMenuStrip oldValue = Properties.GetObject(PropContextMenuStrip) as ContextMenuStrip;
 
                 if (oldValue != value) {
                     EventHandler disposedHandler = new EventHandler(DetachContextMenuStrip); 
 
                     if (oldValue != null) {
                         oldValue.Disposed -= disposedHandler; 
                     }

                     Properties.SetObject(PropContextMenuStrip, value);
 
                     if (value != null) {
                         value.Disposed += disposedHandler; 
                     } 

                     OnContextMenuStripChanged(EventArgs.Empty); 
                 }
             }

        } 
        /// 
        ///  
        ///    [To be supplied.] 
        /// 
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlContextMenuStripChangedDescr)] 
        public event EventHandler ContextMenuStripChanged {
            add {
                Events.AddHandler(EventContextMenuStrip, value);
            } 
            remove {
                Events.RemoveHandler(EventContextMenuStrip, value); 
            } 
        }
 
        /// 
        /// 
        ///     Collection of child controls.
        ///  
        [
        Browsable(false), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Content), 
        SRDescription(SR.ControlControlsDescr)
        ] 
        public ControlCollection Controls {
            get {
                ControlCollection controlsCollection = (ControlCollection)Properties.GetObject(PropControlsCollection);
 
                if (controlsCollection == null) {
                    controlsCollection = CreateControlsInstance(); 
                    Properties.SetObject(PropControlsCollection, controlsCollection); 
                }
                return controlsCollection; 
            }
        }

        ///  
        /// 
        ///    Indicates whether the control has been created. This property is read-only. 
        ///  
        [
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        SRDescription(SR.ControlCreatedDescr)
        ]
        public bool Created { 
            get {
                return(state & STATE_CREATED) != 0; 
            } 
        }
 
        /// 
        /// 
        ///     Returns the CreateParams used to create the handle for this control.
        ///     Inheriting classes should call base.CreateParams in the manor 
        ///     below:
        ///  
        protected virtual CreateParams CreateParams { 
            [
                SecurityPermission(SecurityAction.InheritanceDemand, Flags=SecurityPermissionFlag.UnmanagedCode), 
                SecurityPermission(SecurityAction.LinkDemand, Flags=SecurityPermissionFlag.UnmanagedCode)
            ]
            get {
 
                // CLR4.0 or later, comctl32.dll needs to be loaded explicitly.
                if (UnsafeNativeMethods.GetModuleHandle(ExternDll.Comctl32) == IntPtr.Zero) { 
                    if (UnsafeNativeMethods.LoadLibrary(ExternDll.Comctl32) == IntPtr.Zero) { 
                        int lastWin32Error = Marshal.GetLastWin32Error();
                        throw new Win32Exception(lastWin32Error, SR.GetString(SR.LoadDLLError, ExternDll.Comctl32)); 
                    }
                }

                // In a typical control this is accessed ten times to create and show a control. 
                // It is a net memory savings, then, to maintain a copy on control.
                // 
                if (createParams == null) { 
                    createParams = new CreateParams();
                } 

                CreateParams cp = createParams;
                cp.Style = 0;
                cp.ExStyle = 0; 
                cp.ClassStyle = 0;
                cp.Caption = text; 
 
                cp.X = x;
                cp.Y = y; 
                cp.Width = width;
                cp.Height = height;

                cp.Style = NativeMethods.WS_CLIPCHILDREN; 
                if (GetStyle(ControlStyles.ContainerControl)) {
                    cp.ExStyle |= NativeMethods.WS_EX_CONTROLPARENT; 
                } 
                cp.ClassStyle = NativeMethods.CS_DBLCLKS;
 
                if ((state & STATE_TOPLEVEL) == 0) {
                    // When the window is actually created, we will parent WS_CHILD windows to the
                    // parking form if cp.parent == 0.
                    // 
                    cp.Parent = parent == null ? IntPtr.Zero : parent.InternalHandle;
                    cp.Style |= NativeMethods.WS_CHILD | NativeMethods.WS_CLIPSIBLINGS; 
                } 
                else {
                    cp.Parent = IntPtr.Zero; 
                }

                if ((state & STATE_TABSTOP) != 0) cp.Style |= NativeMethods.WS_TABSTOP;
                if ((state & STATE_VISIBLE) != 0) cp.Style |= NativeMethods.WS_VISIBLE; 

                // Unlike Visible, Windows doesn't correctly inherit disabledness from its parent -- an enabled child 
                // of a disabled parent will look enabled but not get mouse events 
                if (!Enabled) cp.Style |= NativeMethods.WS_DISABLED;
 
                // If we are being hosted as an Ax control, try to prevent the parking window
                // from being created by pre-filling the window handle here.
                //
                if (cp.Parent == IntPtr.Zero && IsActiveX) { 
                    cp.Parent = ActiveXHWNDParent;
                } 
 
                // Set Rtl bits
                if (RightToLeft == RightToLeft.Yes) { 
                    cp.ExStyle |= NativeMethods.WS_EX_RTLREADING;
                    cp.ExStyle |= NativeMethods.WS_EX_RIGHT;
                    cp.ExStyle |= NativeMethods.WS_EX_LEFTSCROLLBAR;
                } 

                return cp; 
            } 
        }
 
        internal virtual void NotifyValidationResult(object sender, CancelEventArgs ev) {
            this.ValidationCancelled = ev.Cancel ;
        }
 
        /// 
        ///     Helper method... 
        /// 
        ///     Triggers validation on the active control, and returns bool indicating whether that control was valid.
        /// 
        ///     The correct way to do this is to find the common ancestor of the active control and this control,
        ///     then request validation to be performed by that common container control.
        ///
        ///     Used by controls that don't participate in the normal enter/leave/validation process, but which 
        ///     want to force form-level validation to occur before they attempt some important action.
        ///  
        internal bool ValidateActiveControl(out bool validatedControlAllowsFocusChange) { 
            bool valid = true;
            validatedControlAllowsFocusChange = false; 
            IContainerControl c = GetContainerControlInternal();
            if (c != null) {
                ContainerControl container = c as ContainerControl;
                if (container != null) { 
                    while (container.ActiveControl == null) {
                        ContainerControl cc; 
                        Control parent = container.ParentInternal; 
                        if (parent != null) {
                            cc = parent.GetContainerControlInternal() as ContainerControl; 
                            if (cc != null) {
                                container = cc;
                            }
                            else { 
                                break;
                            } 
                        } 
                        else {
                            break; 
                        }
                    }

                    valid = container.ValidateInternal(true, out validatedControlAllowsFocusChange); 
                }
            } 
 
            return valid;
        } 

        internal bool ValidationCancelled {
            set {
                SetState(STATE_VALIDATIONCANCELLED, value); 
            }
            get { 
                if (GetState(STATE_VALIDATIONCANCELLED)) { 
                    return true;
                } 
                else {
                    Control parent = this.ParentInternal;
                    if (parent != null) {
                        return parent.ValidationCancelled; 
                    }
 
                    return false; 
                }
            } 
        }

        /// 
        ///     Retrieves the Win32 thread ID of the thread that created the 
        ///     handle for this control.  If the control's handle hasn't been
        ///     created yet, this method will return the current thread's ID. 
        ///  
        /// 
        internal int CreateThreadId { 
            [ResourceExposure(ResourceScope.Process)]
            [ResourceConsumption(ResourceScope.Process)]
            get {
                if (IsHandleCreated) { 
                    int pid;
                    return SafeNativeMethods.GetWindowThreadProcessId(new HandleRef(this, Handle), out pid); 
                } 
                else {
                    return SafeNativeMethods.GetCurrentThreadId(); 
                }
            }
        }
 
        /// 
        ///  
        ///     Retrieves the cursor that will be displayed when the mouse is over this 
        ///     control.
        ///  
        [
        SRCategory(SR.CatAppearance),
        SRDescription(SR.ControlCursorDescr),
        AmbientValue(null) 
        ]
        public virtual Cursor Cursor { 
            get { 
                if (GetState(STATE_USEWAITCURSOR))
                { 
                    return Cursors.WaitCursor;
                }

                Cursor cursor = (Cursor)Properties.GetObject(PropCursor); 
                if (cursor != null) {
                    return cursor; 
                } 

                // We only do ambients for things with "Cursors.Default" 
                // as their default.
                //
                Cursor localDefault = DefaultCursor;
                if (localDefault != Cursors.Default) { 
                    return localDefault;
                } 
 
                Control p = ParentInternal;
                if (p != null) { 
                    return p.Cursor;
                }

                AmbientProperties ambient = AmbientPropertiesService; 
                if (ambient != null && ambient.Cursor != null)
                    return ambient.Cursor; 
 
                return localDefault;
            } 
            set {

                Cursor localCursor = (Cursor)Properties.GetObject(PropCursor);
                Cursor resolvedCursor = Cursor; 
                if (localCursor != value) {
                    Debug.WriteLineIf(IntSecurity.SecurityDemand.TraceVerbose, "ModifyCursor Demanded"); 
                    IntSecurity.ModifyCursor.Demand(); 

                    Properties.SetObject(PropCursor, value); 
                }

                // Other things can change the cursor... we
                // really want to force the correct cursor always... 
                //
                if (IsHandleCreated) { 
                    // We want to instantly change the cursor if the mouse is within our bounds. 
                    // This includes the case where the mouse is over one of our children
                    NativeMethods.POINT p = new NativeMethods.POINT(); 
                    NativeMethods.RECT r = new NativeMethods.RECT();
                    UnsafeNativeMethods.GetCursorPos(p);
                    UnsafeNativeMethods.GetWindowRect(new HandleRef(this, Handle), ref r);
 
                    if ((r.left <= p.x && p.x < r.right && r.top <= p.y && p.y < r.bottom) || UnsafeNativeMethods.GetCapture() == Handle)
                        SendMessage(NativeMethods.WM_SETCURSOR, Handle, (IntPtr)NativeMethods.HTCLIENT); 
                } 

                if (!resolvedCursor.Equals(value)) { 
                    OnCursorChanged(EventArgs.Empty);
                }
            }
        } 

        ///  
        ///  
        ///    [To be supplied.]
        ///  
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlOnCursorChangedDescr)]
        public event EventHandler CursorChanged {
            add {
                Events.AddHandler(EventCursor, value); 
            }
            remove { 
                Events.RemoveHandler(EventCursor, value); 
            }
        } 

        /// 
        /// 
        ///     Retrieves the bindings for this control. 
        /// 
        [ 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Content), 
        SRCategory(SR.CatData),
        SRDescription(SR.ControlBindingsDescr), 
        RefreshProperties(RefreshProperties.All),
        ParenthesizePropertyName(true)
        ]
        public ControlBindingsCollection DataBindings 
        {
            get 
            { 
                ControlBindingsCollection bindings = (ControlBindingsCollection)Properties.GetObject(PropBindings);
                if (bindings == null) 
                {
                    bindings = new ControlBindingsCollection(this);
                    Properties.SetObject(PropBindings, bindings);
                } 
                return bindings;
            } 
        } 

        ///  
        /// 
        ///     The default BackColor of a generic top-level Control.  Subclasses may have
        ///     different defaults.
        ///  
        public static Color DefaultBackColor {
            get { return SystemColors.Control;} 
        } 

        ///  
        /// 
        ///     Deriving classes can override this to configure a default cursor for their control.
        ///     This is more efficient than setting the cursor in the control's constructor,
        ///     and gives automatic support for ShouldSerialize and Reset in the designer. 
        /// 
        protected virtual Cursor DefaultCursor { 
            get { 
                return Cursors.Default;
            } 
        }

        /// 
        ///  
        ///     The default Font of a generic top-level Control.  Subclasses may have
        ///     different defaults. 
        ///  
        public static Font DefaultFont {
            [ResourceExposure(ResourceScope.None)] 
            [ResourceConsumption(ResourceScope.Process, ResourceScope.Process)]
            get {
                if (defaultFont == null) {
                    defaultFont = SystemFonts.DefaultFont; 
                    Debug.Assert(defaultFont != null, "defaultFont wasn't set!");
                } 
 
                return defaultFont;
            } 
        }

        /// 
        ///  
        ///     The default ForeColor of a generic top-level Control.  Subclasses may have
        ///     different defaults. 
        ///  
        public static Color DefaultForeColor {
            get { return SystemColors.ControlText;} 
        }

        /// 
        protected virtual Padding DefaultMargin { 
            get { return CommonProperties.DefaultMargin; }
        } 
 
        /// 
        protected virtual Size DefaultMaximumSize { 
            get { return CommonProperties.DefaultMaximumSize; }
        }

        ///  
        protected virtual Size DefaultMinimumSize {
            get { return CommonProperties.DefaultMinimumSize; } 
        } 

        ///  
        protected virtual Padding DefaultPadding {
            get { return Padding.Empty; }
        }
 
        private RightToLeft DefaultRightToLeft {
            get { return RightToLeft.No; } 
        } 

        ///  
        /// 
        ///     Deriving classes can override this to configure a default size for their control.
        ///     This is more efficient than setting the size in the control's constructor.
        ///  
        protected virtual Size DefaultSize {
            get { return Size.Empty; } 
        } 

        private void DetachContextMenu(object sender, EventArgs e) { 
            ContextMenu = null;
        }

 
        private void DetachContextMenuStrip(object sender, EventArgs e) {
            ContextMenuStrip = null; 
        } 

        // The color to use when drawing disabled text.  Normally we use BackColor, 
        // but that obviously won't work if we're transparent.
        internal Color DisabledColor {
            get {
                Color color = BackColor; 
                if (color.A == 0) {
                    Control control = ParentInternal; 
                    while (color.A == 0) { 
                        if (control == null) {
                            // Don't know what to do, this seems good as anything 
                            color = SystemColors.Control;
                            break;
                        }
                        color = control.BackColor; 
                        control = control.ParentInternal;
                    } 
                } 
                return color;
            } 
        }

        /// 
        ///  
        ///     Returns the client rect of the display area of the control.
        ///     For the base control class, this is identical to getClientRect. 
        ///     However, inheriting controls may want to change this if their client 
        ///     area differs from their display area.
        ///  
        [
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        SRDescription(SR.ControlDisplayRectangleDescr) 
        ]
        public virtual Rectangle DisplayRectangle { 
            [SuppressMessage("Microsoft.Security", "CA2119:SealMethodsThatSatisfyPrivateInterfaces")] 
            get {
                return new Rectangle(0, 0, clientWidth, clientHeight); 
            }
        }

        ///  
        /// 
        ///    Indicates whether the control has been disposed. This 
        ///       property is read-only. 
        /// 
        [ 
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        SRDescription(SR.ControlDisposedDescr)
        ] 
        public bool IsDisposed {
            get { 
                return GetState(STATE_DISPOSED); 
            }
        } 

        /// 
        ///     Disposes of the currently selected font handle (if cached).
        ///  
        private void DisposeFontHandle() {
            if (Properties.ContainsObject(PropFontHandleWrapper)) { 
                FontHandleWrapper fontHandle = Properties.GetObject(PropFontHandleWrapper) as FontHandleWrapper; 
                if( fontHandle != null ){
                    fontHandle.Dispose(); 
                }
                Properties.SetObject(PropFontHandleWrapper, null);
            }
        } 

        ///  
        ///  
        ///    Indicates whether the control is in the process of being disposed. This
        ///       property is read-only. 
        /// 
        [
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden), 
        SRDescription(SR.ControlDisposingDescr)
        ] 
        public bool Disposing { 
            get {
                return GetState(STATE_DISPOSING); 
            }
        }

        ///  
        /// 
        ///     The dock property. The dock property controls to which edge 
        ///     of the container this control is docked to. For example, when docked to 
        ///     the top of the container, the control will be displayed flush at the
        ///     top of the container, extending the length of the container. 
        /// 
        [
        SRCategory(SR.CatLayout),
        Localizable(true), 
        RefreshProperties(RefreshProperties.Repaint),
        DefaultValue(CommonProperties.DefaultDock), 
        SRDescription(SR.ControlDockDescr) 
        ]
        public virtual DockStyle Dock { 
            get {
                return DefaultLayout.GetDock(this);
            }
            set { 
                if(value != Dock) {                        // NDPWhidbey 29434
#if DEBUG 
                    int dbgLayoutCheck = LayoutSuspendCount; 
#endif
                    SuspendLayout(); 
                    try {
                        DefaultLayout.SetDock(this, value);
                        OnDockChanged(EventArgs.Empty);
                    } finally { 
                        ResumeLayout();
                    } 
#if DEBUG 
                    AssertLayoutSuspendCount(dbgLayoutCheck);
#endif 
                }
            }
        }
 
        /// 
        ///  
        ///    [To be supplied.] 
        /// 
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlOnDockChangedDescr)] 
        public event EventHandler DockChanged {
            add {
                Events.AddHandler(EventDock, value);
            } 
            remove {
                Events.RemoveHandler(EventDock, value); 
            } 
        }
 
        /// 
        /// 
        ///    This will enable or disable double buffering.
        ///  
        [
        SRCategory(SR.CatBehavior), 
        SRDescription(SR.ControlDoubleBufferedDescr) 
        ]
        protected virtual bool DoubleBuffered { 
            get {
                return GetStyle(ControlStyles.OptimizedDoubleBuffer);
            }
            set { 
                if (value != DoubleBuffered) {
 
                    if (value) { 
                        SetStyle(ControlStyles.OptimizedDoubleBuffer | ControlStyles.AllPaintingInWmPaint, value);
                    } 
                    else {
                        SetStyle(ControlStyles.OptimizedDoubleBuffer, value);
                    }
                } 
            }
        } 
 
        private bool DoubleBufferingEnabled {
            get { 
#pragma warning disable 618
                return GetStyle(ControlStyles.DoubleBuffer | ControlStyles.UserPaint);
#pragma warning restore 618
            } 
        }
 
        ///  
        /// 
        ///    Indicates whether the control is currently enabled. 
        /// 
        [
        SRCategory(SR.CatBehavior),
        Localizable(true), 
        DispId(NativeMethods.ActiveX.DISPID_ENABLED),
        SRDescription(SR.ControlEnabledDescr) 
        ] 
        public bool Enabled {
            get { 
                // We are only enabled if our parent is enabled
                if (!GetState(STATE_ENABLED))
                    return false;
                else if (ParentInternal == null) 
                    return true;
                else 
                    return ParentInternal.Enabled; 
            }
 
            set {
                bool oldValue = Enabled;
                SetState(STATE_ENABLED, value);
 
                if (oldValue != value) {
                    if (!value) { 
                        SelectNextIfFocused(); 
                    }
 
                    OnEnabledChanged(EventArgs.Empty);
                }
            }
        } 

 
        ///  
        /// 
        ///    Occurs when the control is enabled. 
        /// 
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlOnEnabledChangedDescr)]
        public event EventHandler EnabledChanged {
            add { 
                Events.AddHandler(EventEnabled, value);
            } 
            remove { 
                Events.RemoveHandler(EventEnabled, value);
            } 
        }

        /// 
        ///  
        ///    Indicates whether the control has focus. This property is read-only.
        ///  
        [ 
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden), 
        SRDescription(SR.ControlFocusedDescr)
        ]
        public virtual bool Focused {
            get { 
                return IsHandleCreated && UnsafeNativeMethods.GetFocus() == Handle;
            } 
        } 

        ///  
        /// 
        ///     Retrieves the current font for this control. This will be the font used
        ///     by default for painting and text in the control.
        ///  
        [
        SRCategory(SR.CatAppearance), 
        Localizable(true), 
        DispId(NativeMethods.ActiveX.DISPID_FONT),
        AmbientValue(null), 
        SRDescription(SR.ControlFontDescr)
        ]
        public virtual Font Font {
            [return : MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef=typeof(ActiveXFontMarshaler))] 
            [ResourceExposure(ResourceScope.None)]
            [ResourceConsumption(ResourceScope.Process, ResourceScope.Process)] 
            get { 
                Font font = (Font)Properties.GetObject(PropFont);
                if (font != null) { 
                    return font;
                }

                Font f = GetParentFont(); 
                if (f != null) {
                    return f; 
                } 

                if (IsActiveX) { 
                    f = ActiveXAmbientFont;
                    if (f != null) {
                        return f;
                    } 
                }
 
                AmbientProperties ambient = AmbientPropertiesService; 
                if (ambient != null && ambient.Font != null) {
                    return ambient.Font; 
                }

                return DefaultFont;
            } 
            [param : MarshalAs(UnmanagedType.CustomMarshaler, MarshalTypeRef=typeof(ActiveXFontMarshaler))]
            set { 
                Font local = (Font)Properties.GetObject(PropFont); 
                Font resolved = Font;
 
                bool localChanged = false;
                if (value == null) {
                    if (local != null) {
                        localChanged = true; 
                    }
                } 
                else { 
                    if (local == null) {
                        localChanged = true; 
                    }
                    else {
                        localChanged = !value.Equals(local);
                    } 
                }
 
                if (localChanged) { 
                    // Store new local value
                    // 
                    Properties.SetObject(PropFont, value);

                    // We only fire the Changed event if the "resolved" value
                    // changed, however we must update the font if the local 
                    // value changed...
                    // 
                    if (!resolved.Equals(value)) { 
                        // Cleanup any font handle wrapper...
                        // 
                        DisposeFontHandle();

                        if (Properties.ContainsInteger(PropFontHeight)) {
                            Properties.SetInteger(PropFontHeight, (value == null) ? -1 : value.Height); 
                        }
 
                        // Font is an ambient property.  We need to layout our parent because Font may 
                        // change our size.  We need to layout ourselves because our children may change
                        // size by inheriting the new value. 
                        //
                        using(new LayoutTransaction(ParentInternal, this, PropertyNames.Font)) {
                            OnFontChanged(EventArgs.Empty);
                        } 
                    }
                    else { 
                        if (IsHandleCreated && !GetStyle(ControlStyles.UserPaint)) { 
                            DisposeFontHandle();
                            SetWindowFont(); 
                        }
                    }
                }
            } 
        }
 
        ///  
        /// 
        ///    [To be supplied.] 
        /// 
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlOnFontChangedDescr)]
        public event EventHandler FontChanged {
            add { 
                Events.AddHandler(EventFont, value);
            } 
            remove { 
                Events.RemoveHandler(EventFont, value);
            } 
        }

        internal IntPtr FontHandle {
            get { 
                Font font = (Font)Properties.GetObject(PropFont);
 
                if (font != null) { 
                    FontHandleWrapper fontHandle = (FontHandleWrapper)Properties.GetObject(PropFontHandleWrapper);
                    if (fontHandle == null) { 
                        fontHandle = new FontHandleWrapper(font);

                        Properties.SetObject(PropFontHandleWrapper, fontHandle);
                    } 

                    return fontHandle.Handle; 
                } 

                if (parent != null) { 
                    return parent.FontHandle;
                }

                AmbientProperties ambient = AmbientPropertiesService; 

                if (ambient != null && ambient.Font != null) { 
 
                    FontHandleWrapper fontHandle = null;
 
                    Font currentAmbient = (Font)Properties.GetObject(PropCurrentAmbientFont);

                    if (currentAmbient != null && currentAmbient == ambient.Font) {
                        fontHandle = (FontHandleWrapper)Properties.GetObject(PropFontHandleWrapper); 
                    }
                    else { 
                        Properties.SetObject(PropCurrentAmbientFont, ambient.Font); 
                    }
 
                    if (fontHandle == null) {
                        font =  ambient.Font;
                        fontHandle = new FontHandleWrapper(font);
 
                        Properties.SetObject(PropFontHandleWrapper, fontHandle);
                    } 
 
                    return fontHandle.Handle;
                } 

                return GetDefaultFontHandleWrapper().Handle;
            }
        } 

        ///  
        ///  
        ///    [To be supplied.]
        ///  
        protected int FontHeight {
            get {
                bool found;
                int fontHeight = Properties.GetInteger(PropFontHeight, out found); 
                if (found && fontHeight != -1) {
                    return fontHeight; 
                } 
                else {
                    Font font = (Font)Properties.GetObject(PropFont); 
                    if (font != null) {
                        fontHeight = font.Height;
                        Properties.SetInteger(PropFontHeight, fontHeight);
                        return fontHeight; 
                    }
                } 
 
                //ask the parent if it has the font height
                int localFontHeight = -1; 

                if (ParentInternal != null && ParentInternal.CanAccessProperties) {
                    localFontHeight = ParentInternal.FontHeight;
                } 

                //if we still have a bad value, then get the actual font height 
                if (localFontHeight == -1) { 
                    localFontHeight = Font.Height;
                    Properties.SetInteger(PropFontHeight, localFontHeight); 
                }

                return localFontHeight;
            } 
            set {
                Properties.SetInteger(PropFontHeight, value); 
            } 
        }
 
        /// 
        /// 
        ///     The foreground color of the control.
        ///  
        [
        SRCategory(SR.CatAppearance), 
        DispId(NativeMethods.ActiveX.DISPID_FORECOLOR), 
        SRDescription(SR.ControlForeColorDescr)
        ] 
        public virtual Color ForeColor {
            get {
                Color color = Properties.GetColor(PropForeColor);
                if (!color.IsEmpty) { 
                    return color;
                } 
 
                Control p = ParentInternal;
                if (p != null && p.CanAccessProperties) { 
                    return p.ForeColor;
                }

                Color c = Color.Empty; 

                if (IsActiveX) { 
                    c = ActiveXAmbientForeColor; 
                }
 
                if (c.IsEmpty) {
                    AmbientProperties ambient = AmbientPropertiesService;
                    if (ambient != null)
                        c = ambient.ForeColor; 
                }
 
                if (!c.IsEmpty) 
                    return c;
                else 
                    return DefaultForeColor;
            }

            set { 
                Color c = ForeColor;
                if (!value.IsEmpty || Properties.ContainsObject(PropForeColor)) { 
                    Properties.SetColor(PropForeColor, value); 
                }
                if (!c.Equals(ForeColor)) { 
                    OnForeColorChanged(EventArgs.Empty);
                }
            }
        } 

        ///  
        ///  
        ///    [To be supplied.]
        ///  
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlOnForeColorChangedDescr)]
        public event EventHandler ForeColorChanged {
            add {
                Events.AddHandler(EventForeColor, value); 
            }
            remove { 
                Events.RemoveHandler(EventForeColor, value); 
            }
        } 

        private Font GetParentFont() {
            if (ParentInternal != null && ParentInternal.CanAccessProperties)
                return ParentInternal.Font; 
            else
                return null; 
        } 

        ///  
        [EditorBrowsable(EditorBrowsableState.Advanced)]
        [SuppressMessage("Microsoft.Security", "CA2119:SealMethodsThatSatisfyPrivateInterfaces")]
        public virtual Size GetPreferredSize(Size proposedSize) {
            Size prefSize; 

            if (GetState(STATE_DISPOSING| STATE_DISPOSED)) { 
                // if someone's asking when we're disposing just return what we last had. 
                prefSize = CommonProperties.xGetPreferredSizeCache(this);
            } 
            else {
                 // Switch Size.Empty to maximum possible values
                proposedSize = LayoutUtils.ConvertZeroToUnbounded(proposedSize);
 
                // Force proposedSize to be within the elements constraints.  (This applies
                // minimumSize, maximumSize, etc.) 
                proposedSize = ApplySizeConstraints(proposedSize); 
                if (GetState2(STATE2_USEPREFERREDSIZECACHE)) {
                    Size cachedSize = CommonProperties.xGetPreferredSizeCache(this); 

                    // If the "default" preferred size is being requested, and we have a cached value for it, return it.
                    //
                    if(!cachedSize.IsEmpty && (proposedSize == LayoutUtils.MaxSize)) { 

#if DEBUG 
#if DEBUG_PREFERREDSIZE 
                            Size newPreferredSize = ApplySizeConstraints(GetPreferredSizeCore(proposedSize));
                            bool cacheHitCorrect = (cachedSize == newPreferredSize); 
                            if (!cacheHitCorrect && !GetAnyDisposingInHierarchy()) {
                                Debug.Fail(
                                      "Cached PreferredSize " + cachedSize.ToString()
                                      + " did not match computed: " +newPreferredSize.ToString() 
                                      +". Did we forget to invalidate the cache?\r\n\r\nControl Information: " + WindowsFormsUtils.AssertControlInformation(cacheHitCorrect, this)
                                      + "\r\nChanged Properties\r\n " + CommonProperties.Debug_GetChangedProperties(this)); 
                            } 
#endif
#endif 
                            return cachedSize;
                    }
                }
 

 
                CacheTextInternal = true; 
                try {
                    prefSize = GetPreferredSizeCore(proposedSize); 
                }
                finally {
                    CacheTextInternal = false;
                } 

                // There is no guarantee that GetPreferredSizeCore() return something within 
                // proposedSize, so we apply the element's constraints again. 
                prefSize = ApplySizeConstraints(prefSize);
 
                // If the "default" preferred size was requested, cache the computed value.
                //
                if(GetState2(STATE2_USEPREFERREDSIZECACHE) && proposedSize == LayoutUtils.MaxSize) {
                    CommonProperties.xSetPreferredSizeCache(this, prefSize); 
                }
            } 
            return prefSize; 
        }
 
        // Overriding this method allows us to get the caching and clamping the proposedSize/output to
        // MinimumSize / MaximumSize from GetPreferredSize for free.
        internal virtual Size GetPreferredSizeCore(Size proposedSize) {
            return CommonProperties.GetSpecifiedBounds(this).Size; 
        }
 
        ///  
        /// 
        ///     The HWND handle that this control is bound to. If the handle 
        ///     has not yet been created, this will force handle creation.
        /// 
        [
        Browsable(false), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        DispId(NativeMethods.ActiveX.DISPID_HWND), 
        SRDescription(SR.ControlHandleDescr) 
        ]
        public IntPtr Handle { 
            get {
                if (checkForIllegalCrossThreadCalls &&
                    !inCrossThreadSafeCall &&
                    InvokeRequired) { 
                    throw new InvalidOperationException(SR.GetString(SR.IllegalCrossThreadCall,
                                                                     Name)); 
                } 

                if (!IsHandleCreated) 
                {
                    CreateHandle();
                }
 
                return HandleInternal;
            } 
        } 

        internal IntPtr HandleInternal { 
            get {
                return window.Handle;
            }
        } 

        ///  
        ///  
        ///     True if this control has child controls in its collection.  This
        ///     is more efficient than checking for Controls.Count > 0, but has the 
        ///     same effect.
        /// 
        [
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        SRDescription(SR.ControlHasChildrenDescr) 
        ] 
        public bool HasChildren {
            get { 
                ControlCollection controls = (ControlCollection)Properties.GetObject(PropControlsCollection);
                return controls != null && controls.Count > 0;
            }
        } 

        internal virtual bool HasMenu { 
            get { 
                return false;
            } 
        }

        /// 
        ///  
        ///     The height of this control
        ///  
        [ 
        SRCategory(SR.CatLayout),
        Browsable(false), EditorBrowsable(EditorBrowsableState.Always), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        SRDescription(SR.ControlHeightDescr)
        ]
        public int Height { 
            get {
                return height; 
            } 
            set{
                SetBounds(x, y, width, value, BoundsSpecified.Height); 
            }
        }

        internal bool HostedInWin32DialogManager { 
            get {
                if (!GetState(STATE_CHECKEDHOST)) { 
                    Control topMost = TopMostParent; 
                    if (this != topMost) {
                        SetState(STATE_HOSTEDINDIALOG, topMost.HostedInWin32DialogManager); 
                    }
                    else {
                        IntPtr parentHandle = UnsafeNativeMethods.GetParent(new HandleRef(this, Handle));
                        IntPtr lastParentHandle = parentHandle; 

                        StringBuilder sb = new StringBuilder(32); 
 
                        SetState(STATE_HOSTEDINDIALOG, false);
 
                        while (parentHandle != IntPtr.Zero) {
                            int len = UnsafeNativeMethods.GetClassName(new HandleRef(null, lastParentHandle), null, 0);
                            if (len > sb.Capacity) {
                                sb.Capacity = len + 5; 
                            }
                            UnsafeNativeMethods.GetClassName(new HandleRef(null, lastParentHandle), sb, sb.Capacity); 
 
                            if (sb.ToString() == "#32770") {
                                SetState(STATE_HOSTEDINDIALOG, true); 
                                break;
                            }

                            lastParentHandle = parentHandle; 
                            parentHandle = UnsafeNativeMethods.GetParent(new HandleRef(null, parentHandle));
                        } 
                    } 

                    SetState(STATE_CHECKEDHOST, true); 

                }

                return GetState(STATE_HOSTEDINDIALOG); 
            }
        } 
 
        /// 
        ///  
        ///     Whether or not this control has a handle associated with it.
        /// 
        [
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        SRDescription(SR.ControlHandleCreatedDescr) 
        ] 
        public bool IsHandleCreated {
            get { return window.Handle != IntPtr.Zero; } 
        }

        /// 
        ///     Determines if layout is currently suspended. 
        /// 
        internal bool IsLayoutSuspended { 
            get { 
                return layoutSuspendCount > 0;
            } 
        }

        internal bool IsWindowObscured {
            get { 
                if (!IsHandleCreated || !Visible) {
                    return false; 
                } 

                bool emptyRegion = false; 

                NativeMethods.RECT temp = new NativeMethods.RECT();
                Region working;
                Control parent = ParentInternal; 
                if (parent != null) {
                    while (parent.ParentInternal != null ) { 
                        parent = parent.ParentInternal; 
                    }
                } 

                UnsafeNativeMethods.GetWindowRect(new HandleRef(this, Handle), ref temp);
                working = new Region(Rectangle.FromLTRB(temp.left, temp.top, temp.right, temp.bottom));
 
                try {
                    IntPtr prev; 
                    IntPtr next; 
                    IntPtr start;
                    if (parent != null) { 
                        start = parent.Handle;
                    }
                    else {
                        start = Handle; 
                    }
 
                    for (prev = start; 
                         (next = UnsafeNativeMethods.GetWindow(new HandleRef(null, prev), NativeMethods.GW_HWNDPREV)) != IntPtr.Zero;
                         prev = next) { 

                        UnsafeNativeMethods.GetWindowRect(new HandleRef(null, next), ref temp);
                        Rectangle current = Rectangle.FromLTRB(temp.left, temp.top, temp.right, temp.bottom);
 
                        if (SafeNativeMethods.IsWindowVisible(new HandleRef(null, next))) {
                            working.Exclude(current); 
                        } 
                    }
 

                    Graphics g = CreateGraphics();
                    try {
                        emptyRegion = working.IsEmpty(g); 
                    }
                    finally { 
                        g.Dispose(); 
                    }
                } 
                finally {
                    working.Dispose();
                }
 
                return emptyRegion;
            } 
        } 

        ///  
        ///     Returns the current value of the handle. This may be zero if the handle
        ///     has not been created.
        /// 
        internal IntPtr InternalHandle { 
            get {
                if (!IsHandleCreated) 
                { 
                    return IntPtr.Zero;
                } 
                else
                {
                    return Handle;
                } 
            }
        } 
 
        /// 
        ///  
        ///     Determines if the caller must call invoke when making method
        ///     calls to this control.  Controls in windows forms are bound to a specific thread,
        ///     and are not thread safe.  Therefore, if you are calling a control's method
        ///     from a different thread, you must use the control's invoke method 
        ///     to marshal the call to the proper thread.  This function can be used to
        ///     determine if you must call invoke, which can be handy if you don't know 
        ///     what thread owns a control. 
        ///
        ///     There are five functions on a control that are safe to call from any 
        ///     thread:  GetInvokeRequired, Invoke, BeginInvoke, EndInvoke and
        ///     CreateGraphics.  For all other metohd calls, you should use one of the
        ///     invoke methods.
        ///  
        [
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden), 
        SRDescription(SR.ControlInvokeRequiredDescr)
        ] 
        public bool InvokeRequired {
            get {

                using (new MultithreadSafeCallScope()) 
                {
                    HandleRef hwnd; 
                    if (IsHandleCreated) { 
                        hwnd = new HandleRef(this, Handle);
                    } 
                    else {
                        Control marshalingControl = FindMarshalingControl();

                        if (!marshalingControl.IsHandleCreated) { 
                            return false;
                        } 
 
                        hwnd = new HandleRef(marshalingControl, marshalingControl.Handle);
                    } 

                    int pid;
                    int hwndThread = SafeNativeMethods.GetWindowThreadProcessId(hwnd, out pid);
                    int currentThread = SafeNativeMethods.GetCurrentThreadId(); 
                    return(hwndThread != currentThread);
                } 
            } 
        }
 
        /// 
        /// 
        ///      Indicates whether or not this control is an accessible control
        ///      i.e. whether it should be visible to accessibility applications. 
        /// 
        [ 
        SRCategory(SR.CatBehavior), 
        Browsable(false), EditorBrowsable(EditorBrowsableState.Advanced),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden), 
        SRDescription(SR.ControlIsAccessibleDescr)
        ]
        public bool IsAccessible {
            get { 
                return GetState(STATE_ISACCESSIBLE);
            } 
            set { 
                SetState(STATE_ISACCESSIBLE, value);
            } 
        }

        /// 
        ///     Used to tell if this control is being hosted as an ActiveX control. 
        /// 
        internal bool IsActiveX { 
            get { 
                return GetState2(STATE2_ISACTIVEX);
            } 
        }

        // VsWhidbey 434959 : If the control on which GetContainerControl( ) is called is a ContainerControl, then we dont return the parent
        // but return the same control. This is Everett behavior so we cannot change this since this would be a breaking change. 
        // Hence we have a new internal property IsContainerControl which returns false for all Everett control, but
        // this property is overidden in SplitContainer to return true so that we skip the SplitContainer 
        // and the correct Parent ContainerControl is returned by GetContainerControl(). 
        internal virtual bool IsContainerControl
        { 
            get
            {
                return false;
            } 
        }
 
        ///  
        ///     Used to tell if this control is being hosted in IE.
        ///  
        internal bool IsIEParent {
            get {
                return IsActiveX ? ActiveXInstance.IsIE : false;
            } 
        }
 
        ///  
        ///     Used to tell if the control is mirrored
        ///     Don't call this from CreateParams. Will lead to nasty problems 
        ///     since we might call CreateParams here - you dig!
        /// 
        [
        SRCategory(SR.CatLayout), 
        Browsable(false),
        EditorBrowsable(EditorBrowsableState.Advanced), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden), 
        SRDescription(SR.IsMirroredDescr)
        ] 
        public bool IsMirrored {
            get {
                if (!IsHandleCreated) {
                    CreateParams cp = CreateParams; 
                    SetState(STATE_MIRRORED, (cp.ExStyle & NativeMethods.WS_EX_LAYOUTRTL) != 0);
                } 
                return GetState(STATE_MIRRORED); 
            }
        } 

        /// 
        ///     Specifies whether the control is willing to process mnemonics when hosted in an container ActiveX (Ax Sourcing).
        ///  
        internal virtual bool IsMnemonicsListenerAxSourced
        { 
            get 
            {
                return false; 
            }
        }

        ///  
        ///     Used to tell if this BackColor is Supported
        ///  
        private bool IsValidBackColor (Color c){ 
           if (!c.IsEmpty && !GetStyle(ControlStyles.SupportsTransparentBackColor) && c.A < 255)
           { 
                return false;
           }
           return true;
 
        }
 
        ///  
        /// 
        ///     The left coordinate of this control. 
        /// 
        [
        SRCategory(SR.CatLayout),
        Browsable(false), EditorBrowsable(EditorBrowsableState.Always), 
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden),
        SRDescription(SR.ControlLeftDescr) 
        ] 
        public int Left {
            get { 
                return x;
            }
            set {
                SetBounds(value, y, width, height, BoundsSpecified.X); 
            }
        } 
 
        /// 
        ///  
        ///     The location of this control.
        /// 
        [
        SRCategory(SR.CatLayout), 
        Localizable(true),
        SRDescription(SR.ControlLocationDescr) 
        ] 
        public Point Location {
            get { 
                return new Point(x, y);
            }
            set {
                SetBounds(value.X, value.Y, width, height, BoundsSpecified.Location); 
            }
        } 
 
        /// 
        ///  
        ///    [To be supplied.]
        /// 
        [SRCategory(SR.CatPropertyChanged), SRDescription(SR.ControlOnLocationChangedDescr)]
        public event EventHandler LocationChanged { 
            add {
                Events.AddHandler(EventLocation, value); 
            } 
            remove {
                Events.RemoveHandler(EventLocation, value); 
            }
        }

        ///  
        [
        SRDescription(SR.ControlMarginDescr), 
        SRCategory(SR.CatLayout), 
        Localizable(true)
        ] 
        public Padding Margin
        {
            get { return CommonProperties.GetMargin(this); }
            set 
            {
                // This should be done here rather than in the property store as 
                // some IArrangedElements actually support negative padding. 
                value = LayoutUtils.ClampNegativePaddingToZero(value);
 
                // SetMargin causes a layout as a side effect.
                if (value != Margin)
                {
                    CommonProperties.SetMargin(this, value); 
                    OnMarginChanged(EventArgs.Empty);
                } 
                Debug.Assert(Margin == value, "Error detected while setting Margin."); 
            }
        } 

        /// 
        /// 
        ///    [To be supplied.] 
        /// 
        [SRCategory(SR.CatLayout), SRDescription(SR.ControlOnMarginChangedDescr)] 
        public event EventHandler MarginChanged 
        {
            add 
            {
                Events.AddHandler(EventMarginChanged, value);
            }
            remove 
            {
                Events.RemoveHandler(EventMarginChanged, value); 
            } 
        }
 
        /// 
        [SRCategory(SR.CatLayout)]
        [SRDescription(SR.ControlMaximumSizeDescr)]
        [AmbientValue(typeof(Size), "0, 0")] 
        public virtual Size MaximumSize {
            get { return CommonProperties.GetMaximumSize(this, DefaultMaximumSize); } 
            set { 
                if (value == Size.Empty) {
                    CommonProperties.ClearMaximumSize(this); 
                    Debug.Assert(MaximumSize == DefaultMaximumSize, "Error detected while resetting MaximumSize.");
                }
                else if (value != MaximumSize) {
                    // SetMaximumSize causes a layout as a side effect. 
                    CommonProperties.SetMaximumSize(this, value);
                    Debug.Assert(MaximumSize == value, "Error detected while setting MaximumSize."); 
                } 

            } 
        }

        /// 
        [SRCategory(SR.CatLayout)] 
        [SRDescription(SR.ControlMinimumSizeDescr)]
        public virtual Size MinimumSize { 
            get { return CommonProperties.GetMinimumSize(this, DefaultMinimumSize); } 
            set {
                if (value != MinimumSize) { 
                    // SetMinimumSize causes a layout as a side effect.
                    CommonProperties.SetMinimumSize(this, value);
                }
                Debug.Assert(MinimumSize == value, "Error detected while setting MinimumSize."); 
            }
        } 
 

        ///  
        /// 
        ///     Retrieves the current state of the modifier keys. This will check the
        ///     current state of the shift, control, and alt keys.
        ///  
        public static Keys ModifierKeys {
            get { 
                Keys modifiers = 0; 
                // SECURITYNOTE : only let state of Shift-Control-Alt out...
                // 
                if (UnsafeNativeMethods.GetKeyState((int)Keys.ShiftKey) < 0) modifiers |= Keys.Shift;
                if (UnsafeNativeMethods.GetKeyState((int)Keys.ControlKey) < 0) modifiers |= Keys.Control;
                if (UnsafeNativeMethods.GetKeyState((int)Keys.Menu) < 0) modifiers |= Keys.Alt;
                return modifiers; 
            }
        } 
 
        /// 
        ///  
        ///     The current state of the mouse buttons. This will check the
        ///     current state of the left, right, and middle mouse buttons.
        /// 
        public static MouseButtons MouseButtons { 
            get {
                MouseButtons buttons = (MouseButtons)0; 
                // SECURITYNOTE : only let state of MouseButtons out... 
                //
                if (UnsafeNativeMethods.GetKeyState((int)Keys.LButton) < 0) buttons |= MouseButtons.Left; 
                if (UnsafeNativeMethods.GetKeyState((int)Keys.RButton) < 0) buttons |= MouseButtons.Right;
                if (UnsafeNativeMethods.GetKeyState((int)Keys.MButton) < 0) buttons |= MouseButtons.Middle;
                if (UnsafeNativeMethods.GetKeyState((int)Keys.XButton1) < 0) buttons |= MouseButtons.XButton1;
                if (UnsafeNativeMethods.GetKeyState((int)Keys.XButton2) < 0) buttons |= MouseButtons.XButton2; 
                return buttons;
            } 
        } 

        ///  
        /// 
        ///     The current position of the mouse in screen coordinates.
        /// 
        public static Point MousePosition { 
            get {
                // Reviewed: The following demand has always been commented out since v1.0. In Whidbey, we have 
                // re-reviewed this method to see if it needs protection, but haven't found any threats, so are 
                // going to keep it this way. See VSWhidbey #427555 for details.
                // 
                // Debug.WriteLineIf(IntSecurity.SecurityDemand.TraceVerbose, "ScreenLocationOfThings Demanded");
                // IntSecurity.ScreenLocationOfThings.Demand();

                NativeMethods.POINT pt = new NativeMethods.POINT(); 
                UnsafeNativeMethods.GetCursorPos(pt);
                return new Point(pt.x, pt.y); 
            } 
        }
 
        /// 
        /// 
        ///     Name of this control. The designer will set this to the same
        ///     as the programatic Id "(name)" of the control.  The name can be 
        ///     used as a key into the ControlCollection.
        ///  
        [Browsable(false)] 
        public string Name {
            get { 
                string name = (string)Properties.GetObject(PropName);
                if (String.IsNullOrEmpty(name)) {
                    if (Site != null) {
                        name = Site.Name; 
                    }
 
                    if (name == null) { 
                        name = "";
                    } 
                }

                return name;
            } 
            set {
                if (String.IsNullOrEmpty(value)) { 
                    Properties.SetObject(PropName, null); 
                }
                else { 
                    Properties.SetObject(PropName, value);
                }
            }
        } 

        ///  
        ///  
        ///     The parent of this control.
        ///  
        [
        SRCategory(SR.CatBehavior),
        Browsable(false),
        DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden), 
        SRDescription(SR.ControlParentDescr)
        ] 
        public Control Parent { 
            get {
                Debug.WriteLineIf(IntSecurity.SecurityDemand.TraceVerbose, "G