mcs/class/referencesource/System.Activities.Presentation/System.Activities.Presentation/System/Activities/Presentation/Base/Core/Internal/PropertyEditing/Editors/quickitemtemplateselector.cs

   1 //----------------------------------------------------------------
   2 // Copyright (c) Microsoft Corporation.  All rights reserved.
   3 //----------------------------------------------------------------
   4 namespace System.Activities.Presentation.Internal.PropertyEditing.Editors
   5 {
   6     using System;
   7     using System.Diagnostics.CodeAnalysis;
   8     using System.Windows;
   9     using System.Windows.Controls;
  10     using System.Windows.Media;
  11
  12     using System.Activities.Presentation.Internal.PropertyEditing.FromExpression.Framework.ValueEditors;
  13
  14     // <summary>
  15     // DataTemplateSelector we use in some instances of ChoiceEditor (namely sub-property editor)
  16     // to detect whether the given item is being displayed in the popup or as an inline item.
  17     // Based on that determination, it returns the appropriate DataTemplate.  This is a work-around
  18     // for the problem where we can't determine which NewItemTypeFactory instantiated a given instance.
  19     // Hence, we show the instance Type inline the ComboBox and the factory DisplayName in the drop-down.
  20     // Ideally, we would want to use a different control to handle this scenario.
  21     // </summary>
  22     internal class QuickItemTemplateSelector : DataTemplateSelector
  23     {
  24
  25         private DataTemplate _popupTemplate;
  26         private DataTemplate _inlineTemplate;
  27
  28         public DataTemplate PopupTemplate
  29         {
  30             [SuppressMessage("Microsoft.Performance", "CA1811:AvoidUncalledPrivateCode")]
  31             get { return _popupTemplate; }
  32             [SuppressMessage("Microsoft.Performance", "CA1811:AvoidUncalledPrivateCode")]
  33             set { _popupTemplate = value; }
  34         }
  35
  36         public DataTemplate InlineTemplate
  37         {
  38             [SuppressMessage("Microsoft.Performance", "CA1811:AvoidUncalledPrivateCode")]
  39             get { return _inlineTemplate; }
  40             [SuppressMessage("Microsoft.Performance", "CA1811:AvoidUncalledPrivateCode")]
  41             set { _inlineTemplate = value; }
  42         }
  43
  44         public override DataTemplate SelectTemplate(object item, DependencyObject container)
  45         {
  46             return HasChoiceEditorParent(container) ? _inlineTemplate : _popupTemplate;
  47         }
  48
  49         private bool HasChoiceEditorParent(DependencyObject element)
  50         {
  51             while (element != null)
  52             {
  53                 element = VisualTreeHelper.GetParent(element);
  54                 if (element != null && typeof(ChoiceEditor).IsAssignableFrom(element.GetType()))
  55                 {
  56                     return true;
  57                 }
  58             }
  59
  60             return false;
  61         }
  62     }
  63 }