mcs/class/referencesource/System.Activities.Presentation/System.Activities.Presentation/System/Activities/Presentation/View/TreeView/DesignerTreeViewItem.cs

   1
   2 //----------------------------------------------------------------
   3 // Copyright (c) Microsoft Corporation.  All rights reserved.
   4 //----------------------------------------------------------------
   5
   6 namespace System.Activities.Presentation.View.TreeView
   7 {
   8     using System.Activities.Presentation.Model;
   9     using System.Collections;
  10     using System.Collections.Generic;
  11     using System.ComponentModel;
  12     using System.Runtime;
  13     using System.Text;
  14     using System.Windows;
  15     using System.Windows.Automation.Peers;
  16     using System.Windows.Controls;
  17     using System.Windows.Data;
  18
  19     class DesignerTreeViewItem : TreeViewItem, ITreeViewItemSelectionHandler
  20     {
  21         private bool shouldUpdateViewModel = true;
  22
  23         public DesignerTreeView ParentTreeView { get; set; }
  24
  25         protected override AutomationPeer OnCreateAutomationPeer()
  26         {
  27             return new DesignerTreeViewItemAutomationPeer(this);
  28         }
  29
  30         protected override void OnItemsChanged(Collections.Specialized.NotifyCollectionChangedEventArgs e)
  31         {
  32             if (e.Action == Collections.Specialized.NotifyCollectionChangedAction.Remove)
  33             {
  34                 // Don't select itself when its child items got removed. (Default action of base.OnItemsChanged)
  35                 // The selection should be managed by designer surface.
  36                 return;
  37             }
  38
  39             base.OnItemsChanged(e);
  40         }
  41
  42         internal Dictionary<string, string> GetAutomationItemStatus()
  43         {
  44             Dictionary<string, string> itemStatus = new Dictionary<string, string>();
  45             TreeViewItemViewModel viewModel = this.Header as TreeViewItemViewModel;
  46             if (viewModel != null && viewModel.IsHighlighted)
  47             {
  48                 itemStatus.Add("IsSelection", "True");
  49             }
  50             else
  51             {
  52                 itemStatus.Add("IsSelection", "False");
  53             }
  54
  55             return itemStatus;
  56         }
  57
  58         protected override Windows.DependencyObject GetContainerForItemOverride()
  59         {
  60             DesignerTreeViewItem item = new DesignerTreeViewItem() { ParentTreeView = this.ParentTreeView };
  61             return item;
  62         }
  63
  64         protected override void OnHeaderChanged(object oldHeader, object newHeader)
  65         {
  66             base.OnHeaderChanged(oldHeader, newHeader);
  67
  68             TreeViewItemViewModel source = newHeader as TreeViewItemViewModel;
  69             if (source != null)
  70             {
  71                 source.TreeViewItem = this;
  72             }
  73         }
  74
  75         protected override void OnSelected(Windows.RoutedEventArgs e)
  76         {
  77             base.OnSelected(e);
  78             ParentTreeView.IsSelectionChangeHandledByTreeView = true;
  79             UpdateTreeViewItemViewModel();
  80         }
  81
  82         protected override void OnUnselected(RoutedEventArgs e)
  83         {
  84             base.OnUnselected(e);
  85             if (shouldUpdateViewModel)
  86             {
  87                 TreeViewItemViewModel viewModel = this.Header as TreeViewItemViewModel;
  88                 if (viewModel != null)
  89                 {
  90                     if (viewModel is TreeViewItemModelPropertyViewModel || viewModel is TreeViewItemKeyValuePairModelItemViewModel)
  91                     {
  92                         viewModel.IsHighlighted = false;
  93                     }
  94                     else if (viewModel is TreeViewItemModelItemViewModel)
  95                     {
  96                         TreeViewItemModelItemViewModel modelItemViewModel = (TreeViewItemModelItemViewModel)viewModel;
  97                         if (!modelItemViewModel.HasDesigner)
  98                         {
  99                             modelItemViewModel.IsHighlighted = false;
 100                         }
 101                     }
 102                 }
 103             }
 104         }
 105
 106         private void UpdateTreeViewItemViewModel()
 107         {
 108             if (!shouldUpdateViewModel)
 109             {
 110                 return;
 111             }
 112
 113             if (this.Header is TreeViewItemModelItemViewModel)
 114             {
 115                 TreeViewItemModelItemViewModel modelItemViewModel = (TreeViewItemModelItemViewModel)this.Header;
 116                 if (modelItemViewModel.HasDesigner)
 117                 {
 118                     HighlightModelItemOnDesigner(modelItemViewModel.VisualValue);
 119                 }
 120                 else
 121                 {
 122                     HighlightTreeViewItemAndClearSelectionOnDesigner(modelItemViewModel);
 123                 }
 124             }
 125             else if (this.Header is TreeViewItemModelPropertyViewModel)
 126             {
 127                 TreeViewItemModelPropertyViewModel modelPropertyViewModel = (TreeViewItemModelPropertyViewModel)this.Header;
 128                 HighlightTreeViewItemAndClearSelectionOnDesigner(modelPropertyViewModel);
 129             }
 130             else if (this.Header is TreeViewItemKeyValuePairModelItemViewModel)
 131             {
 132                 TreeViewItemKeyValuePairModelItemViewModel keyValuePairItem = (TreeViewItemKeyValuePairModelItemViewModel)this.Header;
 133                 HighlightTreeViewItemAndClearSelectionOnDesigner(keyValuePairItem);
 134             }
 135             else
 136             {
 137                 Fx.Assert("Invaild logic if Header is not TreeViewItemModelItemViewModel/TreeViewItemModelPropertyViewModel/TreeViewItemDictionaryModelItemViewModel");
 138             }
 139         }
 140
 141         private void HighlightModelItemOnDesigner(ModelItem selectedModelItem)
 142         {
 143             if (selectedModelItem != null)
 144             {
 145                 Selection.SelectOnly(this.ParentTreeView.Context, selectedModelItem);
 146                 // Set highlight to visual value.
 147                 // Don't use "Focus()" since it will steal keyboard focus and disable
 148                 // keyboard navigation.
 149                 selectedModelItem.Highlight();
 150             }
 151         }
 152
 153         private void HighlightTreeViewItemAndClearSelectionOnDesigner(TreeViewItemViewModel viewModel)
 154         {
 155             this.ParentTreeView.Context.Items.SetValue(new Selection());
 156             viewModel.IsHighlighted = true;
 157         }
 158
 159         void ITreeViewItemSelectionHandler.Select()
 160         {
 161             // Invoked from ViewModel, needn't update ViewModel again.
 162             shouldUpdateViewModel = false;
 163             this.IsSelected = true;
 164             shouldUpdateViewModel = true;
 165         }
 166
 167         void ITreeViewItemSelectionHandler.Unselect()
 168         {
 169             // Invoked from ViewModel, needn't update ViewModel again.
 170             shouldUpdateViewModel = false;
 171             this.IsSelected = false;
 172             shouldUpdateViewModel = true;
 173         }
 174
 175         private class DesignerTreeViewItemAutomationPeer : TreeViewItemAutomationPeer
 176         {
 177             private DesignerTreeViewItem owner;
 178
 179             public DesignerTreeViewItemAutomationPeer(DesignerTreeViewItem owner)
 180                 : base(owner)
 181             {
 182                 Fx.Assert(owner != null, "DesignerTreeViewItemAutomationPeer should not accept a null owner.");
 183                 this.owner = owner;
 184             }
 185
 186             protected override AutomationControlType GetAutomationControlTypeCore()
 187             {
 188                 return AutomationControlType.TreeItem;
 189             }
 190
 191             protected override string GetItemStatusCore()
 192             {
 193                 Dictionary<string, string> itemStatus = this.owner.GetAutomationItemStatus();
 194                 StringBuilder builder = new StringBuilder();
 195                 foreach (KeyValuePair<string, string> item in itemStatus)
 196                 {
 197                     builder.AppendFormat("{0}={1} ", item.Key, item.Value);
 198                 }
 199
 200                 return builder.ToString();
 201             }
 202         }
 203     }
 204 }