mcs/class/referencesource/System.Activities.Presentation/System.Activities.Presentation/System/Activities/Presentation/Base/Core/Internal/PropertyEditing/FromExpression/Framework/Controls/WorkaroundPopup.cs

   1 // -------------------------------------------------------------------
   2 // Copyright (c) Microsoft Corporation. All Rights Reserved.
   3 // -------------------------------------------------------------------
   4 //From \\authoring\Sparkle\Source\1.0.1083.0\Common\Source\Framework\Controls
   5 namespace System.Activities.Presentation.Internal.PropertyEditing.FromExpression.Framework.Controls
   6 {
   7     using System;
   8     using System.Windows;
   9     using System.Windows.Input;
  10     using System.Windows.Controls.Primitives;
  11     using System.Windows.Media;
  12     using System.Activities.Presentation.Internal.PropertyEditing.FromExpression.Framework.UserInterface;
  13
  14     // <summary>
  15     // This class contains specific behavior for the Popup associated with PropertyContainer.
  16     // Basically, it is a workaround for Windows OS bug #1745919.  The "StaysOpen = false" setting
  17     // on a Popup does not function as we expect when the Popup is created within another
  18     // "StaysOpen = false" popup (or if anything has capture).  What happens is the Popup first
  19     // checks if anything has capture, and only takes capture if nothing else has taken it.  But the
  20     // StaysOpen behavior is implemented using the capture, so we lose that.  Also, related to that
  21     // the Closed event will not be called, so to workaround both of those issues we essentially
  22     // re-implement the popup capture grabbing code, except we take capture no matter what.
  23     // </summary>
  24     internal class WorkaroundPopup : Popup
  25     {
  26         private bool releasingCapture = false;
  27
  28         protected override void OnOpened(EventArgs e)
  29         {
  30             this.releasingCapture = false;
  31
  32             if (this.Child != null)
  33             {
  34                 this.Child.Focusable = true;
  35                 this.Child.Focus();
  36                 Mouse.Capture(this.Child, CaptureMode.SubTree);
  37             }
  38             this.SetValue(FocusScopeManager.FocusScopePriorityProperty, 1);
  39             base.OnOpened(e);
  40         }
  41
  42         protected override void OnGotKeyboardFocus(KeyboardFocusChangedEventArgs e)
  43         {
  44             base.OnGotKeyboardFocus(e);
  45         }
  46
  47         protected override void OnLostKeyboardFocus(KeyboardFocusChangedEventArgs e)
  48         {
  49             base.OnLostKeyboardFocus(e);
  50         }
  51
  52         protected override void OnGotFocus(RoutedEventArgs e)
  53         {
  54             base.OnGotFocus(e);
  55         }
  56
  57         protected override void OnLostFocus(RoutedEventArgs e)
  58         {
  59             base.OnLostFocus(e);
  60         }
  61
  62         protected override void OnLostMouseCapture(System.Windows.Input.MouseEventArgs e)
  63         {
  64             object sender = this;
  65             // This code is a stripped down implementation of Popup.OnMouseLostCapture
  66             if (!this.releasingCapture && Mouse.Captured != this.Child)
  67             {
  68                 if (e.OriginalSource == this.Child)
  69                 {
  70                     if (Mouse.Captured == null)
  71                     {
  72                         this.IsOpen = false;
  73                     }
  74                 }
  75                 else if (this.IsDescendentOfPopup(sender as DependencyObject))
  76                 {
  77                     if (this.IsOpen && Mouse.Captured == null)
  78                     {
  79                         Mouse.Capture(this.Child, CaptureMode.SubTree);
  80                     }
  81                 }
  82                 else
  83                 {
  84                     this.IsOpen = false;
  85                 }
  86             }
  87             base.OnLostMouseCapture(e);
  88         }
  89
  90         protected override void OnPreviewMouseDown(MouseButtonEventArgs e)
  91         {
  92             // Check if the mouse down occured within the popup, if it did, leave the popup open.  If it didn't, then close
  93             // the popup and release capture.
  94             if (e.OriginalSource == this.Child && this.Child.InputHitTest(e.GetPosition(this.Child)) == null)
  95             {
  96                 this.IsOpen = false;
  97                 this.ReleaseChildMouseCapture();
  98             }
  99             base.OnMouseDown(e);
 100         }
 101
 102         private bool IsDescendentOfPopup(DependencyObject currentObject)
 103         {
 104             while (currentObject != null)
 105             {
 106                 if (currentObject == this || currentObject == this.Child)
 107                 {
 108                     return true;
 109                 }
 110                 currentObject = VisualTreeHelper.GetParent(currentObject);
 111             }
 112
 113             return false;
 114         }
 115
 116         private void ReleaseChildMouseCapture()
 117         {
 118             if (Mouse.Captured == this.Child)
 119             {
 120                 this.releasingCapture = true;
 121                 Mouse.Capture(null);
 122                 this.releasingCapture = false;
 123             }
 124         }
 125
 126         protected override void OnKeyDown(KeyEventArgs e)
 127         {
 128             if (e.Key == Key.Escape)
 129             {
 130                 this.IsOpen = false;
 131                 this.ReleaseChildMouseCapture();
 132             }
 133             base.OnKeyDown(e);
 134         }
 135
 136         protected override void OnClosed(EventArgs e)
 137         {
 138             this.ReleaseChildMouseCapture();
 139             base.OnClosed(e);
 140         }
 141     }
 142 }