From e54aee8d0a385c3a9343e18eec1b92c7ea316450 Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@gmail.com>
Date: Fri, 7 Feb 2020 09:38:38 +0100
Subject: [PATCH] Make TreeViewPage work.

---
 samples/ControlCatalog/Pages/TreeViewPage.xaml    |  2 +-
 samples/ControlCatalog/Pages/TreeViewPage.xaml.cs | 15 ++++++++-------
 2 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/samples/ControlCatalog/Pages/TreeViewPage.xaml b/samples/ControlCatalog/Pages/TreeViewPage.xaml
index 3a81e2ed02..c9e3fafb6d 100644
--- a/samples/ControlCatalog/Pages/TreeViewPage.xaml
+++ b/samples/ControlCatalog/Pages/TreeViewPage.xaml
@@ -10,7 +10,7 @@
                 HorizontalAlignment="Center"
                 Spacing="16">
       <StackPanel Orientation="Vertical" Spacing="8">
-        <TreeView Items="{Binding Items}" SelectedItems="{Binding SelectedItems}" SelectionMode="{Binding SelectionMode}" Width="250" Height="350">
+        <TreeView Items="{Binding Items}" Selection="{Binding Selection}" SelectionMode="{Binding SelectionMode}" Width="250" Height="350">
           <TreeView.ItemTemplate>
             <TreeDataTemplate ItemsSource="{Binding Children}">
               <TextBlock Text="{Binding Header}"/>
diff --git a/samples/ControlCatalog/Pages/TreeViewPage.xaml.cs b/samples/ControlCatalog/Pages/TreeViewPage.xaml.cs
index 1f35f05f1d..44fbc9126e 100644
--- a/samples/ControlCatalog/Pages/TreeViewPage.xaml.cs
+++ b/samples/ControlCatalog/Pages/TreeViewPage.xaml.cs
@@ -28,21 +28,22 @@ namespace ControlCatalog.Pages
             {
                 Node root = new Node();
                 Items = root.Children;
-                SelectedItems = new ObservableCollection<Node>();
+                Selection = new SelectionModel();
 
                 AddItemCommand = ReactiveCommand.Create(() =>
                 {
-                    Node parentItem = SelectedItems.Count > 0 ? SelectedItems[0] : root;
+                    Node parentItem = Selection.SelectedItems.Count > 0 ? 
+                        (Node)Selection.SelectedItems[0] : root;
                     parentItem.AddNewItem();
                 });
 
                 RemoveItemCommand = ReactiveCommand.Create(() =>
                 {
-                    while (SelectedItems.Count > 0)
+                    while (Selection.SelectedItems.Count > 0)
                     {
-                        Node lastItem = SelectedItems[0];
+                        Node lastItem = (Node)Selection.SelectedItems[0];
                         RecursiveRemove(Items, lastItem);
-                        SelectedItems.Remove(lastItem);
+                        Selection.Deselect(Selection.SelectedIndices[0]);
                     }
 
                     bool RecursiveRemove(ObservableCollection<Node> items, Node selectedItem)
@@ -67,7 +68,7 @@ namespace ControlCatalog.Pages
 
             public ObservableCollection<Node> Items { get; }
 
-            public ObservableCollection<Node> SelectedItems { get; }
+            public SelectionModel Selection { get; }
 
             public ReactiveCommand<Unit, Unit> AddItemCommand { get; }
 
@@ -78,7 +79,7 @@ namespace ControlCatalog.Pages
                 get => _selectionMode;
                 set
                 {
-                    SelectedItems.Clear();
+                    Selection.ClearSelection();
                     this.RaiseAndSetIfChanged(ref _selectionMode, value);
                 }
             }