Code:
/ FX-1434 / FX-1434 / 1.0 / untmp / whidbey / REDBITS / ndp / fx / src / Misc / GDI / DeviceContext2.cs / 2 / DeviceContext2.cs
//------------------------------------------------------------------------------ //// Copyright (c) Microsoft Corporation. All rights reserved. // //----------------------------------------------------------------------------- #if WINFORMS_NAMESPACE namespace System.Windows.Forms.Internal #elif DRAWING_NAMESPACE namespace System.Drawing.Internal #else namespace System.Experimental.Gdi #endif { using System; using System.Internal; using System.Security; using System.Runtime.InteropServices; using System.Diagnostics; using System.ComponentModel; using System.Drawing; using System.Globalization; ////// /// Represents a Win32 device context. Provides operations for setting some of the properties /// of a device context. It's the managed wrapper for an HDC. /// /// This class is divided into two files separating the code that needs to be compiled into /// reatail builds and debugging code. /// /// WARNING: The properties of the dc are obtained on-demand, this object is light-weight because /// of that; if you need to put back the old value after changing a property you need to get it /// first and cache it. /// #if WINFORMS_PUBLIC_GRAPHICS_LIBRARY public #else internal #endif sealed partial class DeviceContext : MarshalByRefObject, IDeviceContext, IDisposable { WindowsFont selectedFont; ////// See DeviceContext.cs for information about this class. The class has been split to be able /// to compile the right set of functionalities into different assemblies. /// public WindowsFont ActiveFont { get { return selectedFont; } } ////// DC background color. /// public Color BackgroundColor { get { return ColorTranslator.FromWin32(IntUnsafeNativeMethods.GetBkColor( new HandleRef( this, this.Hdc ))); } #if WINFORMS_PUBLIC_GRAPHICS_LIBRARY set { SetBackgroundColor( value ); } #endif } ////// Sets the DC background color and returns the old value. /// public Color SetBackgroundColor( Color newColor ) { return ColorTranslator.FromWin32(IntUnsafeNativeMethods.SetBkColor( new HandleRef( this, this.Hdc ), ColorTranslator.ToWin32(newColor))); } ////// DC background mode. /// public DeviceContextBackgroundMode BackgroundMode { get { return (DeviceContextBackgroundMode) IntUnsafeNativeMethods.GetBkMode( new HandleRef( this, this.Hdc ) ); } #if WINFORMS_PUBLIC_GRAPHICS_LIBRARY set { SetBackgroundMode(value); } #endif } ////// Sets the DC background mode and returns the old value. /// public DeviceContextBackgroundMode SetBackgroundMode( DeviceContextBackgroundMode newMode ) { return (DeviceContextBackgroundMode) IntUnsafeNativeMethods.SetBkMode(new HandleRef(this, this.Hdc), (int) newMode); } ////// ROP2 currently on the DC. /// public DeviceContextBinaryRasterOperationFlags BinaryRasterOperation { get { return (DeviceContextBinaryRasterOperationFlags) IntUnsafeNativeMethods.GetROP2( new HandleRef( this, this.Hdc ) ); } /* * */ } ////// Sets the DC ROP2 and returns the old value. /// public DeviceContextBinaryRasterOperationFlags SetRasterOperation(DeviceContextBinaryRasterOperationFlags rasterOperation ) { return (DeviceContextBinaryRasterOperationFlags) IntUnsafeNativeMethods.SetROP2(new HandleRef(this, this.Hdc), (int) rasterOperation); } ////// Get the number of pixels per logical inch along the device axes. /// In a system with multiple display monitors, this value is the same for all monitors. /// public Size Dpi { get { return new Size(GetDeviceCapabilities(DeviceCapabilities.LogicalPixelsX), GetDeviceCapabilities(DeviceCapabilities.LogicalPixelsY)); } } ////// Get the number of pixels per logical inch along the device width. /// In a system with multiple display monitors, this value is the same for all monitors. /// public int DpiX { get { return GetDeviceCapabilities(DeviceCapabilities.LogicalPixelsX); } } ////// Get the number of pixels per logical inch along the device (screen) height. /// In a system with multiple display monitors, this value is the same for all monitors. /// public int DpiY { get { return GetDeviceCapabilities(DeviceCapabilities.LogicalPixelsY); } } ////// The font selected into the device context. /// It's OK to call dispose on it, the HFONT won't be deleted since the WindowsFont did not create it, /// it got it from the HDC. /// public WindowsFont Font { get { #if OPTIMIZED_MEASUREMENTDC if (MeasurementDCInfo.IsMeasurementDC(this)) { WindowsFont font = MeasurementDCInfo.LastUsedFont; if (font != null && (font.Hfont != IntPtr.Zero)) { #if DEBUG WindowsFont currentDCFont = WindowsFont.FromHdc( this.Hdc ); if (!font.Equals(currentDCFont) ) { // just use the face name, as ToString will call here re-entrantly. string lastUsedFontInfo = (font != null) ? font.Name : "null"; string currentFontInfo = (currentDCFont != null) ? currentDCFont.Name : "null"; Debug.Fail("Font does not match... Current: " + currentFontInfo + " Last known: " + lastUsedFontInfo); } #endif return font; } } #endif // Returns the currently selected object in the dc. // Note: for common DCs, GetDC assigns default attributes to the DC each time it is retrieved, // the default font is System. return WindowsFont.FromHdc( this.Hdc ); } #if WINFORMS_PUBLIC_GRAPHICS_LIBRARY set { Debug.Assert( value != null, "value == null." ); IntPtr hOldFont = SelectFont( value ); IntUnsafeNativeMethods.IntDeleteObject(new HandleRef(null, hOldFont)); } #endif } ////// Gets a DeviceContext object initialized to refer to the primary screen device. /// Consider using WindowsGraphicsCacheManager.MeasurementGraphics instead. /// public static DeviceContext ScreenDC { get { return DeviceContext.FromHwnd(IntPtr.Zero); } } internal void DisposeFont(bool disposing) { if (disposing) { DeviceContexts.RemoveDeviceContext(this); } if (selectedFont != null && selectedFont.Hfont != IntPtr.Zero) { IntPtr hCurrentFont = IntUnsafeNativeMethods.GetCurrentObject(new HandleRef(this, hDC), IntNativeMethods.OBJ_FONT); if (hCurrentFont == selectedFont.Hfont) { // select initial font back in IntUnsafeNativeMethods.SelectObject(new HandleRef(this, this.Hdc), new HandleRef( null, hInitialFont)); hCurrentFont = hInitialFont; } selectedFont.Dispose(disposing); selectedFont = null; } } ////// Selects the specified object into the dc. If the specified object is the same as the one currently selected /// in the dc, the object is not set and a null value is returned. /// public IntPtr SelectFont( WindowsFont font ) { // Fonts are one of the most expensive objects to select in an hdc and in many cases we are passed a Font that is the // same as the one already selected in the dc so to avoid a perf hit we get the hdc font's log font and compare it // with the one passed in before selecting it in the hdc. // Also, we avoid performing GDI operations that if done on an enhanced metafile DC would add an entry to it, hence // reducing the size of the metafile. if( font.Equals( this.Font )) { return IntPtr.Zero; } IntPtr result = SelectObject( font.Hfont, GdiObjectType.Font); WindowsFont previousFont = selectedFont; selectedFont = font; hCurrentFont = font.Hfont; // the measurement DC always leaves fonts selected for pref reasons. // in this case, we need to diposse the font since the original // creator didn't fully dispose. if (previousFont != null) { #if DEBUG //Disabling this assert until DevDiv Bugs 95968 gets fixed //Debug.Assert(previousFont.Hfont != IntPtr.Zero, "A font has been disposed before it was unselected from the DC. This will leak a GDI handle on Win9x! Call ResetFont()"); #endif if (MeasurementDCInfo.IsMeasurementDC(this)) { previousFont.Dispose(); } } #if OPTIMIZED_MEASUREMENTDC // once we've changed the font, update the last used font. if (MeasurementDCInfo.IsMeasurementDC(this)) { if (result != IntPtr.Zero) { MeasurementDCInfo.LastUsedFont = font; } else { // there was an error selecting the Font into the DC, we dont know anything about it. MeasurementDCInfo.Reset(); } } #endif return result; } public void ResetFont() { #if OPTIMIZED_MEASUREMENTDC // in this case, GDI will copy back the previously saved font into the DC. // we dont actually know what the font is in our measurement DC so // we need to clear it off. MeasurementDCInfo.ResetIfIsMeasurementDC(this.Hdc); #endif IntUnsafeNativeMethods.SelectObject(new HandleRef(this, this.Hdc), new HandleRef( null, hInitialFont )); selectedFont = null; hCurrentFont = hInitialFont; } ////// Retrieves device-specific information for this device. /// public int GetDeviceCapabilities( DeviceCapabilities capabilityIndex ) { return IntUnsafeNativeMethods.GetDeviceCaps( new HandleRef( this, this.Hdc ), (int) capabilityIndex ); } ////// DC map mode. /// public DeviceContextMapMode MapMode { get { return (DeviceContextMapMode) IntUnsafeNativeMethods.GetMapMode( new HandleRef( this, this.Hdc ) ); } #if WINFORMS_PUBLIC_GRAPHICS_LIBRARY set { SetMapMode(value); } #endif } public bool IsFontOnContextStack(WindowsFont wf) { if (contextStack == null) { return false; } foreach (GraphicsState g in contextStack) { if (g.hFont == wf.Hfont) { return true; } } return false; } ////// Sets the DC map mode and returns the old value. /// public DeviceContextMapMode SetMapMode( DeviceContextMapMode newMode ) { return (DeviceContextMapMode) IntUnsafeNativeMethods.SetMapMode( new HandleRef(this, this.Hdc), (int) newMode ); } ////// Selects the specified object into the dc and returns the old object. /// public IntPtr SelectObject(IntPtr hObj, GdiObjectType type) { switch (type) { case GdiObjectType.Pen: hCurrentPen = hObj; break; case GdiObjectType.Brush: hCurrentBrush = hObj; break; case GdiObjectType.Bitmap: hCurrentBmp = hObj; break; } return IntUnsafeNativeMethods.SelectObject(new HandleRef(this, this.Hdc), new HandleRef( null, hObj)); } ////// DC text alignment. /// public DeviceContextTextAlignment TextAlignment { get { return (DeviceContextTextAlignment) IntUnsafeNativeMethods.GetTextAlign( new HandleRef( this, this.Hdc ) ); } #if WINFORMS_PUBLIC_GRAPHICS_LIBRARY set { SetTextAlignment(value); } #endif } ////// Sets the DC text alignment and returns the old value. /// public DeviceContextTextAlignment SetTextAlignment( DeviceContextTextAlignment newAligment ) { return (DeviceContextTextAlignment) IntUnsafeNativeMethods.SetTextAlign(new HandleRef(this, this.Hdc), (int) newAligment ); } ////// DC current text color. /// public Color TextColor { get { return ColorTranslator.FromWin32(IntUnsafeNativeMethods.GetTextColor( new HandleRef( this, this.Hdc ) )); } #if WINFORMS_PUBLIC_GRAPHICS_LIBRARY set { SetTextColor(value); } #endif } ////// Sets the DC text color and returns the old value. /// public Color SetTextColor( Color newColor ) { return ColorTranslator.FromWin32(IntUnsafeNativeMethods.SetTextColor(new HandleRef( this, this.Hdc), ColorTranslator.ToWin32(newColor))); } ////// DC Viewport Extent in device units. /// public Size ViewportExtent { get { IntNativeMethods.SIZE size = new IntNativeMethods.SIZE(); IntUnsafeNativeMethods.GetViewportExtEx( new HandleRef( this, this.Hdc ), size ); return size.ToSize(); } set { SetViewportExtent( value ); } } ////// Sets the DC Viewport extent to the specified value and returns its previous value; extent values are in device units. /// public Size SetViewportExtent( Size newExtent ) { IntNativeMethods.SIZE oldExtent = new IntNativeMethods.SIZE(); IntUnsafeNativeMethods.SetViewportExtEx( new HandleRef( this, this.Hdc ), newExtent.Width, newExtent.Height, oldExtent ); return oldExtent.ToSize(); } ////// DC Viewport Origin in device units. /// public Point ViewportOrigin { get { IntNativeMethods.POINT point = new IntNativeMethods.POINT(); IntUnsafeNativeMethods.GetViewportOrgEx( new HandleRef( this, this.Hdc ), point ); return point.ToPoint(); } set { SetViewportOrigin( value ); } } ////// Sets the DC Viewport origin to the specified value and returns its previous value; origin values are in device units. /// public Point SetViewportOrigin( Point newOrigin ) { IntNativeMethods.POINT oldOrigin = new IntNativeMethods.POINT(); IntUnsafeNativeMethods.SetViewportOrgEx( new HandleRef( this, this.Hdc ), newOrigin.X, newOrigin.Y, oldOrigin ); return oldOrigin.ToPoint(); } } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007. // Copyright (c) Microsoft Corporation. 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