Greatly improved TabbedLayout behavior when bound to Categories

Main/WpfPropertyGrid/Design/TabbedLayout.cs

@@ -25,6 +25,8 @@ namespace System.Windows.Controls.WpfPropertyGrid.Design
   /// </summary>
   public class TabbedLayout : TabControl
   {
+    private static readonly IValueConverter visibilityConverter = new BooleanToVisibilityConverter();
+
     /// <summary>
     /// The fallback header for a tab if no header custom is provided.
     /// </summary>
@@ -229,9 +231,62 @@ protected override void PrepareContainerForItemOverride(DependencyObject element
 
           tab.SetBinding(HeaderedContentControl.HeaderProperty, bHeader);
         }
+
+        if (item is GridEntry)
+        {
+          var binding = new Binding("IsVisible")
+          {
+            Source = item,
+            Mode = BindingMode.OneWay,
+            UpdateSourceTrigger = UpdateSourceTrigger.PropertyChanged,
+            Converter = visibilityConverter
+          };
+          tab.SetBinding(UIElement.VisibilityProperty, binding);
+        }
+
+        tab.IsVisibleChanged += OnTabVisibilityChanged;
       }
     }
 
+    private void OnTabVisibilityChanged(object sender, DependencyPropertyChangedEventArgs e)
+    {
+      var tabItem = sender as TabbedLayoutItem;
+      if (tabItem == null || tabItem.DataContext == null) return;
+
+      bool isVisible = (bool)e.NewValue;
+
+
+      if (isVisible && GetVisibleEntryCount() == 1)
+      {
+        var visibleEntry = GetFirstVisibleEntry();
+        if (SelectedItem != visibleEntry)
+          SelectedItem = visibleEntry;
+      }
+      else if (tabItem.IsSelected)
+      {
+        if (GetVisibleEntryCount() == 0)
+        {
+          SelectedItem = null;
+          return;
+        }
+
+        if (Items.IndexOf(tabItem.DataContext) > 0)
+          SelectedIndex--;
+        else if (Items.Count > 1)
+          SelectedIndex++;
+      }
+    }
+
+    private GridEntry GetFirstVisibleEntry()
+    {
+      return Items.OfType<GridEntry>().FirstOrDefault(item => item.IsVisible);
+    }
+
+    private int GetVisibleEntryCount()
+    {
+      return Items.OfType<GridEntry>().Count(item => item.IsVisible);
+    }
+
     /// <summary>
     /// Determines if the specified item is (or is eligible to be) its own ItemContainer.
     /// </summary>

Main/WpfPropertyGrid/Design/TabbedLayout.xaml

@@ -7,7 +7,12 @@
 
   <BooleanToVisibilityConverter x:Key="booleanToVisibilityConverter"/>
 
-  <Style TargetType="{x:Type design:TabbedLayout}" BasedOn="{StaticResource {x:Type TabControl}}"/>  
+  <Style TargetType="{x:Type design:TabbedLayout}" BasedOn="{StaticResource {x:Type TabControl}}">
+    <Style.Resources>
+      <design:TabbedLayoutTemplateSelector x:Key="TabbedLayoutTemplateSelector"/>
+    </Style.Resources>
+    <Setter Property="ContentTemplateSelector" Value="{StaticResource TabbedLayoutTemplateSelector}"/>
+  </Style> 
 
   <Style x:Key="TabItemFocusVisual">
     <Setter Property="Control.Template">

Main/WpfPropertyGrid/Design/TabbedLayoutTemplateSelector.cs

@@ -0,0 +1,33 @@
+namespace System.Windows.Controls.WpfPropertyGrid.Design
+{
+  public class TabbedLayoutTemplateSelector : DataTemplateSelector
+  {
+    private readonly ResourceLocator _resourceLocator = new ResourceLocator();
+
+    public override DataTemplate SelectTemplate(object item, DependencyObject container)
+    {
+      var category = item as CategoryItem;
+      if (category != null)
+      {
+        var template = FindEditorTemplate(category);
+        if (template != null) return template;
+      }
+
+      return base.SelectTemplate(item, container);
+    }
+
+    protected virtual DataTemplate FindEditorTemplate(CategoryItem category)
+    {
+      if (category == null) return null;
+
+      var editor = category.Editor;
+
+      if (editor == null) return null;
+
+      var template = editor.InlineTemplate as DataTemplate;
+      if (template != null) return template;
+
+      return _resourceLocator.GetResource(editor.InlineTemplate) as DataTemplate;
+    }
+  }
+}

Main/WpfPropertyGrid/WpfPropertyGrid.csproj

@@ -159,6 +159,7 @@
     <Compile Include="DataResource.cs" />
     <Compile Include="Design\GridEntryContainer.cs" />
     <Compile Include="Design\GridEntryLayout.cs" />
+    <Compile Include="Design\TabbedLayoutTemplateSelector.cs" />
     <Compile Include="EditorCollection.cs" />
     <Compile Include="Controls\SearchTextBox.cs" />
     <Compile Include="Design\CategoryContainer.cs" />