mcs/class/referencesource/System.Activities.Presentation/System.Activities.Presentation/System/Activities/Presentation/View/TreeView/DesignerTreeView.xaml.cs

   1 //----------------------------------------------------------------
   2 // Copyright (c) Microsoft Corporation.  All rights reserved.
   3 //----------------------------------------------------------------
   4
   5 namespace System.Activities.Presentation.View.TreeView
   6 {
   7     using System.Activities.Presentation.Model;
   8     using System.Collections.ObjectModel;
   9     using System.Windows;
  10     using System.Windows.Threading;
  11
  12     partial class DesignerTreeView : System.Windows.Controls.TreeView
  13     {
  14         private TreeViewItemModelItemViewModel rootModelItemViewModel;
  15         private bool isSelectionSubscribed;
  16
  17         internal bool IsSelectionChangeHandledByTreeView { get; set; }
  18
  19         public DesignerTreeView()
  20         {
  21             InitializeComponent();
  22         }
  23
  24         public EditingContext Context
  25         {
  26             get;
  27             private set;
  28         }
  29
  30         public void SetRootDesigner(ModelItem modelItem)
  31         {
  32             rootModelItemViewModel = new TreeViewItemModelItemViewModel(null, modelItem);
  33             this.ItemsSource = new ObservableCollection<TreeViewItemModelItemViewModel>() { rootModelItemViewModel };
  34
  35             if (!isSelectionSubscribed)
  36             {
  37                 Selection.Subscribe(Context, ModelItemSelectionChanged);
  38                 isSelectionSubscribed = true;
  39             }
  40         }
  41
  42         public void Initialize(EditingContext context)
  43         {
  44             this.Context = context;
  45         }
  46
  47         private void ModelItemSelectionChanged(Selection selection)
  48         {
  49             // AutoExpand only when designerTreeView didn't handle the selection change in modelItem
  50             if (this.IsSelectionChangeHandledByTreeView)
  51             {
  52                 this.IsSelectionChangeHandledByTreeView = false;
  53             }
  54             else
  55             {
  56                 if (selection.PrimarySelection != null)
  57                 {
  58                     TreeViewItemViewModel itemToBeSelected = DesignerTreeAutoExpandHelper.Expand(this.rootModelItemViewModel, selection.PrimarySelection);
  59                     // itemToBeSelected == null means needn't AutoExpand.
  60                     if (itemToBeSelected != null)
  61                     {
  62                         this.Dispatcher.BeginInvoke(DispatcherPriority.ApplicationIdle, new Action(() =>
  63                         {
  64                             // TreeViewItemViewModel may got removed before Idle.
  65                             if (itemToBeSelected.IsAlive && itemToBeSelected.TreeViewItem != null)
  66                             {
  67                                 itemToBeSelected.TreeViewItem.Select();
  68                             }
  69                             // reset this flag to false, because the operation is done.
  70                             // The flag will be used for next operation.
  71                             this.IsSelectionChangeHandledByTreeView = false;
  72                         }));
  73                     }
  74                 }
  75             }
  76         }
  77
  78         public void RestoreDesignerStates()
  79         {
  80             this.InvalidateMeasure();
  81         }
  82
  83         protected override DependencyObject GetContainerForItemOverride()
  84         {
  85             return new DesignerTreeViewItem() { ParentTreeView = this };
  86         }
  87     }
  88 }