TabItem.cs source code in C# .NET

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Code:

/ Dotnetfx_Win7_3.5.1 / Dotnetfx_Win7_3.5.1 / 3.5.1 / DEVDIV / depot / DevDiv / releases / Orcas / NetFXw7 / wpf / src / Framework / System / Windows / Controls / TabItem.cs / 1 / TabItem.cs

                            //---------------------------------------------------------------------------- 
//
// Copyright (C) Microsoft Corporation.  All rights reserved.
//
//--------------------------------------------------------------------------- 

using System; 
using System.Diagnostics; 
using MS.Internal;
using MS.Internal.KnownBoxes; 
using MS.Utility;
using System.Windows.Threading;
using System.ComponentModel;
using System.Windows.Automation; 
using System.Windows.Automation.Peers;
using System.Windows.Media; 
using System.Windows.Input; 
using System.Windows;
using System.Windows.Data; 

using System.Windows.Controls.Primitives;

// Disable CS3001: Warning as Error: not CLS-compliant 
#pragma warning disable 3001
 
namespace System.Windows.Controls 
{
    ///  
    ///     A child item of TabControl.
    /// 
    [DefaultEvent("IsSelectedChanged")]
    public class TabItem : HeaderedContentControl 
    {
        //------------------------------------------------------------------- 
        // 
        //  Constructors
        // 
        //-------------------------------------------------------------------

        #region Constructors
 
        /// 
        ///     Default DependencyObject constructor 
        ///  
        /// 
        ///     Automatic determination of current Dispatcher. Use alternative constructor 
        ///     that accepts a Dispatcher for best performance.
        /// 
        public TabItem() : base()
        { 
        }
 
        static TabItem() 
        {
            EventManager.RegisterClassHandler(typeof(TabItem), AccessKeyManager.AccessKeyPressedEvent, new AccessKeyPressedEventHandler(OnAccessKeyPressed)); 

            DefaultStyleKeyProperty.OverrideMetadata(typeof(TabItem), new FrameworkPropertyMetadata(typeof(TabItem)));
            _dType = DependencyObjectType.FromSystemTypeInternal(typeof(TabItem));
            KeyboardNavigation.DirectionalNavigationProperty.OverrideMetadata(typeof(TabItem), new FrameworkPropertyMetadata(KeyboardNavigationMode.Contained)); 
            KeyboardNavigation.TabNavigationProperty.OverrideMetadata(typeof(TabItem), new FrameworkPropertyMetadata(KeyboardNavigationMode.Local));
        } 
 
        #endregion
 
        //--------------------------------------------------------------------
        //
        //  Properties
        // 
        //-------------------------------------------------------------------
 
        #region Properties 
        /// 
        ///     Indicates whether this TabItem is selected. 
        /// 
        public static readonly DependencyProperty IsSelectedProperty =
                Selector.IsSelectedProperty.AddOwner(typeof(TabItem),
                        new FrameworkPropertyMetadata(BooleanBoxes.FalseBox, 
                                FrameworkPropertyMetadataOptions.BindsTwoWayByDefault | FrameworkPropertyMetadataOptions.AffectsParentMeasure | FrameworkPropertyMetadataOptions.Journal,
                                new PropertyChangedCallback(OnIsSelectedChanged))); 
 
        /// 
        ///     Indicates whether this TabItem is selected. 
        /// 
        [Bindable(true), Category("Appearance")]
        public bool IsSelected
        { 
            get { return (bool) GetValue(IsSelectedProperty); }
            set { SetValue(IsSelectedProperty, BooleanBoxes.Box(value)); } 
        } 

        private static void OnIsSelectedChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) 
        {
            TabItem tabItem = d as TabItem;

            bool isSelected = (bool)e.NewValue; 

            TabControl parentTabControl = tabItem.TabControlParent; 
            if (parentTabControl != null) 
            {
                parentTabControl.RaiseIsSelectedChangedAutomationEvent(tabItem, isSelected); 
            }

            if (isSelected)
            { 
                tabItem.OnSelected(new RoutedEventArgs(Selector.SelectedEvent, tabItem));
            } 
            else 
            {
                tabItem.OnUnselected(new RoutedEventArgs(Selector.UnselectedEvent, tabItem)); 
            }


            // KeyboardNavigation use bounding box reduced with DirectionalNavigationMargin when calculating the next element in directional navigation 
            // Because TabItem use negative margins some TabItems overlap which would changes the directional navigation if we don't reduce the bounding box
            if (isSelected) 
            { 
                Binding binding = new Binding("Margin");
                binding.Source = tabItem; 
                BindingOperations.SetBinding(tabItem, KeyboardNavigation.DirectionalNavigationMarginProperty, binding);
            }
            else
            { 
                BindingOperations.ClearBinding(tabItem, KeyboardNavigation.DirectionalNavigationMarginProperty);
            } 
        } 

        ///  
        ///     Event indicating that the IsSelected property is now true.
        /// 
        /// Event arguments
        protected virtual void OnSelected(RoutedEventArgs e) 
        {
            HandleIsSelectedChanged(true, e); 
        } 

        ///  
        ///     Event indicating that the IsSelected property is now false.
        /// 
        /// Event arguments
        protected virtual void OnUnselected(RoutedEventArgs e) 
        {
            HandleIsSelectedChanged(false, e); 
        } 

        private void HandleIsSelectedChanged(bool newValue, RoutedEventArgs e) 
        {
#if OLD_AUTOMATION
            if (AutomationProvider.IsActive)
            { 
                RaiseAutomationIsSelectedChanged(!newValue, newValue);
            } 
#endif 

            RaiseEvent(e); 
        }

#if OLD_AUTOMATION
        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.NoInlining)] 
        private void RaiseAutomationIsSelectedChanged(bool oldValue, bool newValue)
        { 
            AutomationProvider.RaiseAutomationPropertyChangedEvent(this, SelectionItemPatternIdentifiers.IsSelectedProperty, oldValue, newValue); 
        }
#endif 

        #region TabStripPlacement
        /// 
        ///     Property key for TabStripPlacementProperty. 
        /// 
        private static readonly DependencyPropertyKey TabStripPlacementPropertyKey = 
                DependencyProperty.RegisterReadOnly( 
                        "TabStripPlacement",
                        typeof(Dock), 
                        typeof(TabItem),
                        new FrameworkPropertyMetadata(
                                Dock.Top,
                                null, 
                                new CoerceValueCallback(CoerceTabStripPlacement)));
 
        ///  
        /// Specifies the placement of the TabItem
        ///  
        public static readonly DependencyProperty TabStripPlacementProperty =
            TabStripPlacementPropertyKey.DependencyProperty;

        private static object CoerceTabStripPlacement(DependencyObject d, object value) 
        {
            TabControl tabControl = ((TabItem)d).TabControlParent; 
            return (tabControl != null) ? tabControl.TabStripPlacement : value; 
        }
 
        /// 
        /// Specifies the placement of the TabItem. This read-only property get its value from the TabControl parent
        /// 
        public Dock TabStripPlacement 
        {
            get 
            { 
                return (Dock)GetValue(TabStripPlacementProperty);
            } 
        }

        internal override void OnAncestorChanged()
        { 
            // TabStripPlacement depends on the logical parent -- so invalidate it when that changes
            CoerceValue(TabStripPlacementProperty); 
        } 

        #endregion TabStripPlacement 

        #endregion

        //-------------------------------------------------------------------- 
        //
        //  Protected Methods 
        // 
        //--------------------------------------------------------------------
 
        #region Protected Methods

        /// 
        /// Creates AutomationPeer () 
        /// 
        protected override AutomationPeer OnCreateAutomationPeer() 
        { 
            return new TabItemWrapperAutomationPeer(this);
        } 

        /// 
        /// This is the method that responds to the MouseLeftButtonDownEvent event.
        ///  
        /// 
        protected override void OnMouseLeftButtonDown(MouseButtonEventArgs e) 
        { 
            // We should process only the direct events in case TabItem is the selected one
            // otherwise we are getting this event when we click on TabItem content because it is in the logical subtree 
            if (e.Source == this || !IsSelected)
            {
                if (SetFocus())
                    e.Handled = true; 
            }
            base.OnMouseLeftButtonDown(e); 
        } 

        ///  
        /// Focus event handler
        /// 
        /// 
        protected override void OnPreviewGotKeyboardFocus(KeyboardFocusChangedEventArgs e) 
        {
            base.OnPreviewGotKeyboardFocus(e); 
            if (!e.Handled && e.NewFocus == this) 
            {
                if (!IsSelected && TabControlParent != null) 
                {
                    IsSelected = true;
                    // If focus moved in result of selection - handle the event to prevent setting focus back on the new item
                    if (e.OldFocus != Keyboard.FocusedElement) 
                    {
                        e.Handled = true; 
                    } 
                    else if (GetBoolField(BoolField.SetFocusOnContent))
                    { 
                        ContentPresenter selectedContentPresenter = TabControlParent.SelectedContentPresenter;
                        if (selectedContentPresenter != null)
                        {
                            TabControlParent.UpdateLayout(); // Wait for layout 
                            bool success = selectedContentPresenter.MoveFocus(new TraversalRequest(FocusNavigationDirection.First));
 
                            // If we successfully move focus inside the content then don't set focus to the header 
                            if (success)
                                e.Handled = true; 
                        }
                    }
                }
            } 
        }
 
        ///  
        /// The Access key for this control was invoked.
        ///  
        protected override void OnAccessKey(AccessKeyEventArgs e)
        {
            SetFocus();
        } 

        ///  
        ///     This method is invoked when the Content property changes. 
        /// 
        /// The old value of the Content property. 
        /// The new value of the Content property.
        protected override void OnContentChanged(object oldContent, object newContent)
        {
            base.OnContentChanged(oldContent, newContent); 

            // If this is the selected TabItem then we should update TabControl.SelectedContent 
            if (IsSelected) 
            {
                TabControl tabControl = TabControlParent; 
                if (tabControl != null)
                {
                    tabControl.SelectedContent = newContent;
                } 
            }
        } 
 
        /// 
        ///     This method is invoked when the ContentTemplate property changes. 
        /// 
        /// The old value of the ContentTemplate property.
        /// The new value of the ContentTemplate property.
        protected override void OnContentTemplateChanged(DataTemplate oldContentTemplate, DataTemplate newContentTemplate) 
        {
            base.OnContentTemplateChanged(oldContentTemplate, newContentTemplate); 
 
            // If this is the selected TabItem then we should update TabControl.SelectedContentTemplate
            if (IsSelected) 
            {
                TabControl tabControl = TabControlParent;
                if (tabControl != null)
                { 
                    tabControl.SelectedContentTemplate = newContentTemplate;
                } 
            } 
        }
 
        /// 
        ///     This method is invoked when the ContentTemplateSelector property changes.
        /// 
        /// The old value of the ContentTemplateSelector property. 
        /// The new value of the ContentTemplateSelector property.
        protected override void OnContentTemplateSelectorChanged(DataTemplateSelector oldContentTemplateSelector, DataTemplateSelector newContentTemplateSelector) 
        { 
            base.OnContentTemplateSelectorChanged(oldContentTemplateSelector, newContentTemplateSelector);
 
            // If this is the selected TabItem then we should update TabControl.SelectedContentTemplateSelector
            if (IsSelected)
            {
                TabControl tabControl = TabControlParent; 
                if (tabControl != null)
                { 
                    tabControl.SelectedContentTemplateSelector = newContentTemplateSelector; 
                }
            } 
        }

        #endregion
 
        //-------------------------------------------------------------------
        // 
        //  Private Methods 
        //
        //-------------------------------------------------------------------- 

        #region Private Methods

        private static void OnAccessKeyPressed(object sender, AccessKeyPressedEventArgs e) 
        {
            if (!e.Handled && e.Scope == null) 
            { 
                TabItem tabItem = sender as TabItem;
 
                if (e.Target == null)
                {
                    e.Target = tabItem;
                } 
                else if (!tabItem.IsSelected) // If TabItem is not active it is a scope for its content elements
                { 
                    e.Scope = tabItem; 
                    e.Handled = true;
                } 
            }
        }

        internal bool SetFocus() 
        {
            bool returnValue = false; 
 
            if (!GetBoolField(BoolField.SettingFocus))
            { 
                TabItem currentFocus = Keyboard.FocusedElement as TabItem;

                // If current focus was another TabItem in the same TabControl - dont set focus on content
                bool setFocusOnContent = ((currentFocus == this) || (currentFocus == null) || (currentFocus.TabControlParent != this.TabControlParent)); 
                SetBoolField(BoolField.SettingFocus, true);
                SetBoolField(BoolField.SetFocusOnContent, setFocusOnContent); 
                try 
                {
                    returnValue = Focus() || setFocusOnContent; 
                }
                finally
                {
                    SetBoolField(BoolField.SettingFocus, false); 
                    SetBoolField(BoolField.SetFocusOnContent, false);
                } 
            } 

            return returnValue; 
        }

        private TabControl TabControlParent
        { 
            get
            { 
                return ItemsControl.ItemsControlFromItemContainer(this) as TabControl; 
            }
        } 

        #endregion

        //------------------------------------------------------------------- 
        //
        //  Private Fields 
        // 
        //-------------------------------------------------------------------
 
        #region Private Fields

        private bool GetBoolField(BoolField field)
        { 
            return (_tabItemBoolFieldStore & field) != 0;
        } 
 
        private void SetBoolField(BoolField field, bool value)
        { 
            if (value)
            {
                _tabItemBoolFieldStore |= field;
            } 
            else
            { 
                _tabItemBoolFieldStore &= (~field); 
            }
        } 

        [Flags]
        private enum BoolField
        { 
            SetFocusOnContent      = 0x10, // This flag determine if we want to set focus on active TabItem content
            SettingFocus           = 0x20, // This flag indicates that the TabItem is in the process of setting focus 
 
            // By default ListBoxItem is selectable
            DefaultValue = 0, 
        }

        BoolField _tabItemBoolFieldStore = BoolField.DefaultValue;
 
        #endregion Private Fields
 
        #region DTypeThemeStyleKey 

        // Returns the DependencyObjectType for the registered ThemeStyleKey's default 
        // value. Controls will override this method to return approriate types.
        internal override DependencyObjectType DTypeThemeStyleKey
        {
            get { return _dType; } 
        }
 
        private static DependencyObjectType _dType; 

        #endregion DTypeThemeStyleKey 
    }

}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
//---------------------------------------------------------------------------- 
//
// Copyright (C) Microsoft Corporation.  All rights reserved.
//
//--------------------------------------------------------------------------- 

using System; 
using System.Diagnostics; 
using MS.Internal;
using MS.Internal.KnownBoxes; 
using MS.Utility;
using System.Windows.Threading;
using System.ComponentModel;
using System.Windows.Automation; 
using System.Windows.Automation.Peers;
using System.Windows.Media; 
using System.Windows.Input; 
using System.Windows;
using System.Windows.Data; 

using System.Windows.Controls.Primitives;

// Disable CS3001: Warning as Error: not CLS-compliant 
#pragma warning disable 3001
 
namespace System.Windows.Controls 
{
    ///  
    ///     A child item of TabControl.
    /// 
    [DefaultEvent("IsSelectedChanged")]
    public class TabItem : HeaderedContentControl 
    {
        //------------------------------------------------------------------- 
        // 
        //  Constructors
        // 
        //-------------------------------------------------------------------

        #region Constructors
 
        /// 
        ///     Default DependencyObject constructor 
        ///  
        /// 
        ///     Automatic determination of current Dispatcher. Use alternative constructor 
        ///     that accepts a Dispatcher for best performance.
        /// 
        public TabItem() : base()
        { 
        }
 
        static TabItem() 
        {
            EventManager.RegisterClassHandler(typeof(TabItem), AccessKeyManager.AccessKeyPressedEvent, new AccessKeyPressedEventHandler(OnAccessKeyPressed)); 

            DefaultStyleKeyProperty.OverrideMetadata(typeof(TabItem), new FrameworkPropertyMetadata(typeof(TabItem)));
            _dType = DependencyObjectType.FromSystemTypeInternal(typeof(TabItem));
            KeyboardNavigation.DirectionalNavigationProperty.OverrideMetadata(typeof(TabItem), new FrameworkPropertyMetadata(KeyboardNavigationMode.Contained)); 
            KeyboardNavigation.TabNavigationProperty.OverrideMetadata(typeof(TabItem), new FrameworkPropertyMetadata(KeyboardNavigationMode.Local));
        } 
 
        #endregion
 
        //--------------------------------------------------------------------
        //
        //  Properties
        // 
        //-------------------------------------------------------------------
 
        #region Properties 
        /// 
        ///     Indicates whether this TabItem is selected. 
        /// 
        public static readonly DependencyProperty IsSelectedProperty =
                Selector.IsSelectedProperty.AddOwner(typeof(TabItem),
                        new FrameworkPropertyMetadata(BooleanBoxes.FalseBox, 
                                FrameworkPropertyMetadataOptions.BindsTwoWayByDefault | FrameworkPropertyMetadataOptions.AffectsParentMeasure | FrameworkPropertyMetadataOptions.Journal,
                                new PropertyChangedCallback(OnIsSelectedChanged))); 
 
        /// 
        ///     Indicates whether this TabItem is selected. 
        /// 
        [Bindable(true), Category("Appearance")]
        public bool IsSelected
        { 
            get { return (bool) GetValue(IsSelectedProperty); }
            set { SetValue(IsSelectedProperty, BooleanBoxes.Box(value)); } 
        } 

        private static void OnIsSelectedChanged(DependencyObject d, DependencyPropertyChangedEventArgs e) 
        {
            TabItem tabItem = d as TabItem;

            bool isSelected = (bool)e.NewValue; 

            TabControl parentTabControl = tabItem.TabControlParent; 
            if (parentTabControl != null) 
            {
                parentTabControl.RaiseIsSelectedChangedAutomationEvent(tabItem, isSelected); 
            }

            if (isSelected)
            { 
                tabItem.OnSelected(new RoutedEventArgs(Selector.SelectedEvent, tabItem));
            } 
            else 
            {
                tabItem.OnUnselected(new RoutedEventArgs(Selector.UnselectedEvent, tabItem)); 
            }


            // KeyboardNavigation use bounding box reduced with DirectionalNavigationMargin when calculating the next element in directional navigation 
            // Because TabItem use negative margins some TabItems overlap which would changes the directional navigation if we don't reduce the bounding box
            if (isSelected) 
            { 
                Binding binding = new Binding("Margin");
                binding.Source = tabItem; 
                BindingOperations.SetBinding(tabItem, KeyboardNavigation.DirectionalNavigationMarginProperty, binding);
            }
            else
            { 
                BindingOperations.ClearBinding(tabItem, KeyboardNavigation.DirectionalNavigationMarginProperty);
            } 
        } 

        ///  
        ///     Event indicating that the IsSelected property is now true.
        /// 
        /// Event arguments
        protected virtual void OnSelected(RoutedEventArgs e) 
        {
            HandleIsSelectedChanged(true, e); 
        } 

        ///  
        ///     Event indicating that the IsSelected property is now false.
        /// 
        /// Event arguments
        protected virtual void OnUnselected(RoutedEventArgs e) 
        {
            HandleIsSelectedChanged(false, e); 
        } 

        private void HandleIsSelectedChanged(bool newValue, RoutedEventArgs e) 
        {
#if OLD_AUTOMATION
            if (AutomationProvider.IsActive)
            { 
                RaiseAutomationIsSelectedChanged(!newValue, newValue);
            } 
#endif 

            RaiseEvent(e); 
        }

#if OLD_AUTOMATION
        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.NoInlining)] 
        private void RaiseAutomationIsSelectedChanged(bool oldValue, bool newValue)
        { 
            AutomationProvider.RaiseAutomationPropertyChangedEvent(this, SelectionItemPatternIdentifiers.IsSelectedProperty, oldValue, newValue); 
        }
#endif 

        #region TabStripPlacement
        /// 
        ///     Property key for TabStripPlacementProperty. 
        /// 
        private static readonly DependencyPropertyKey TabStripPlacementPropertyKey = 
                DependencyProperty.RegisterReadOnly( 
                        "TabStripPlacement",
                        typeof(Dock), 
                        typeof(TabItem),
                        new FrameworkPropertyMetadata(
                                Dock.Top,
                                null, 
                                new CoerceValueCallback(CoerceTabStripPlacement)));
 
        ///  
        /// Specifies the placement of the TabItem
        ///  
        public static readonly DependencyProperty TabStripPlacementProperty =
            TabStripPlacementPropertyKey.DependencyProperty;

        private static object CoerceTabStripPlacement(DependencyObject d, object value) 
        {
            TabControl tabControl = ((TabItem)d).TabControlParent; 
            return (tabControl != null) ? tabControl.TabStripPlacement : value; 
        }
 
        /// 
        /// Specifies the placement of the TabItem. This read-only property get its value from the TabControl parent
        /// 
        public Dock TabStripPlacement 
        {
            get 
            { 
                return (Dock)GetValue(TabStripPlacementProperty);
            } 
        }

        internal override void OnAncestorChanged()
        { 
            // TabStripPlacement depends on the logical parent -- so invalidate it when that changes
            CoerceValue(TabStripPlacementProperty); 
        } 

        #endregion TabStripPlacement 

        #endregion

        //-------------------------------------------------------------------- 
        //
        //  Protected Methods 
        // 
        //--------------------------------------------------------------------
 
        #region Protected Methods

        /// 
        /// Creates AutomationPeer () 
        /// 
        protected override AutomationPeer OnCreateAutomationPeer() 
        { 
            return new TabItemWrapperAutomationPeer(this);
        } 

        /// 
        /// This is the method that responds to the MouseLeftButtonDownEvent event.
        ///  
        /// 
        protected override void OnMouseLeftButtonDown(MouseButtonEventArgs e) 
        { 
            // We should process only the direct events in case TabItem is the selected one
            // otherwise we are getting this event when we click on TabItem content because it is in the logical subtree 
            if (e.Source == this || !IsSelected)
            {
                if (SetFocus())
                    e.Handled = true; 
            }
            base.OnMouseLeftButtonDown(e); 
        } 

        ///  
        /// Focus event handler
        /// 
        /// 
        protected override void OnPreviewGotKeyboardFocus(KeyboardFocusChangedEventArgs e) 
        {
            base.OnPreviewGotKeyboardFocus(e); 
            if (!e.Handled && e.NewFocus == this) 
            {
                if (!IsSelected && TabControlParent != null) 
                {
                    IsSelected = true;
                    // If focus moved in result of selection - handle the event to prevent setting focus back on the new item
                    if (e.OldFocus != Keyboard.FocusedElement) 
                    {
                        e.Handled = true; 
                    } 
                    else if (GetBoolField(BoolField.SetFocusOnContent))
                    { 
                        ContentPresenter selectedContentPresenter = TabControlParent.SelectedContentPresenter;
                        if (selectedContentPresenter != null)
                        {
                            TabControlParent.UpdateLayout(); // Wait for layout 
                            bool success = selectedContentPresenter.MoveFocus(new TraversalRequest(FocusNavigationDirection.First));
 
                            // If we successfully move focus inside the content then don't set focus to the header 
                            if (success)
                                e.Handled = true; 
                        }
                    }
                }
            } 
        }
 
        ///  
        /// The Access key for this control was invoked.
        ///  
        protected override void OnAccessKey(AccessKeyEventArgs e)
        {
            SetFocus();
        } 

        ///  
        ///     This method is invoked when the Content property changes. 
        /// 
        /// The old value of the Content property. 
        /// The new value of the Content property.
        protected override void OnContentChanged(object oldContent, object newContent)
        {
            base.OnContentChanged(oldContent, newContent); 

            // If this is the selected TabItem then we should update TabControl.SelectedContent 
            if (IsSelected) 
            {
                TabControl tabControl = TabControlParent; 
                if (tabControl != null)
                {
                    tabControl.SelectedContent = newContent;
                } 
            }
        } 
 
        /// 
        ///     This method is invoked when the ContentTemplate property changes. 
        /// 
        /// The old value of the ContentTemplate property.
        /// The new value of the ContentTemplate property.
        protected override void OnContentTemplateChanged(DataTemplate oldContentTemplate, DataTemplate newContentTemplate) 
        {
            base.OnContentTemplateChanged(oldContentTemplate, newContentTemplate); 
 
            // If this is the selected TabItem then we should update TabControl.SelectedContentTemplate
            if (IsSelected) 
            {
                TabControl tabControl = TabControlParent;
                if (tabControl != null)
                { 
                    tabControl.SelectedContentTemplate = newContentTemplate;
                } 
            } 
        }
 
        /// 
        ///     This method is invoked when the ContentTemplateSelector property changes.
        /// 
        /// The old value of the ContentTemplateSelector property. 
        /// The new value of the ContentTemplateSelector property.
        protected override void OnContentTemplateSelectorChanged(DataTemplateSelector oldContentTemplateSelector, DataTemplateSelector newContentTemplateSelector) 
        { 
            base.OnContentTemplateSelectorChanged(oldContentTemplateSelector, newContentTemplateSelector);
 
            // If this is the selected TabItem then we should update TabControl.SelectedContentTemplateSelector
            if (IsSelected)
            {
                TabControl tabControl = TabControlParent; 
                if (tabControl != null)
                { 
                    tabControl.SelectedContentTemplateSelector = newContentTemplateSelector; 
                }
            } 
        }

        #endregion
 
        //-------------------------------------------------------------------
        // 
        //  Private Methods 
        //
        //-------------------------------------------------------------------- 

        #region Private Methods

        private static void OnAccessKeyPressed(object sender, AccessKeyPressedEventArgs e) 
        {
            if (!e.Handled && e.Scope == null) 
            { 
                TabItem tabItem = sender as TabItem;
 
                if (e.Target == null)
                {
                    e.Target = tabItem;
                } 
                else if (!tabItem.IsSelected) // If TabItem is not active it is a scope for its content elements
                { 
                    e.Scope = tabItem; 
                    e.Handled = true;
                } 
            }
        }

        internal bool SetFocus() 
        {
            bool returnValue = false; 
 
            if (!GetBoolField(BoolField.SettingFocus))
            { 
                TabItem currentFocus = Keyboard.FocusedElement as TabItem;

                // If current focus was another TabItem in the same TabControl - dont set focus on content
                bool setFocusOnContent = ((currentFocus == this) || (currentFocus == null) || (currentFocus.TabControlParent != this.TabControlParent)); 
                SetBoolField(BoolField.SettingFocus, true);
                SetBoolField(BoolField.SetFocusOnContent, setFocusOnContent); 
                try 
                {
                    returnValue = Focus() || setFocusOnContent; 
                }
                finally
                {
                    SetBoolField(BoolField.SettingFocus, false); 
                    SetBoolField(BoolField.SetFocusOnContent, false);
                } 
            } 

            return returnValue; 
        }

        private TabControl TabControlParent
        { 
            get
            { 
                return ItemsControl.ItemsControlFromItemContainer(this) as TabControl; 
            }
        } 

        #endregion

        //------------------------------------------------------------------- 
        //
        //  Private Fields 
        // 
        //-------------------------------------------------------------------
 
        #region Private Fields

        private bool GetBoolField(BoolField field)
        { 
            return (_tabItemBoolFieldStore & field) != 0;
        } 
 
        private void SetBoolField(BoolField field, bool value)
        { 
            if (value)
            {
                _tabItemBoolFieldStore |= field;
            } 
            else
            { 
                _tabItemBoolFieldStore &= (~field); 
            }
        } 

        [Flags]
        private enum BoolField
        { 
            SetFocusOnContent      = 0x10, // This flag determine if we want to set focus on active TabItem content
            SettingFocus           = 0x20, // This flag indicates that the TabItem is in the process of setting focus 
 
            // By default ListBoxItem is selectable
            DefaultValue = 0, 
        }

        BoolField _tabItemBoolFieldStore = BoolField.DefaultValue;
 
        #endregion Private Fields
 
        #region DTypeThemeStyleKey 

        // Returns the DependencyObjectType for the registered ThemeStyleKey's default 
        // value. Controls will override this method to return approriate types.
        internal override DependencyObjectType DTypeThemeStyleKey
        {
            get { return _dType; } 
        }
 
        private static DependencyObjectType _dType; 

        #endregion DTypeThemeStyleKey 
    }

}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
                        

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