[Win] Fix uncommon not expanding on search

Fixes #504

Author: Eric Maupin

Xamarin.PropertyEditing.Windows/CategoryExpander.cs

@@ -1,36 +1,10 @@
-using System;
-using System.Windows;
-using System.Windows.Controls;
-using System.Windows.Data;
 using System.Windows.Input;
-using System.Windows.Media;
-using Xamarin.PropertyEditing.ViewModels;
 
 namespace Xamarin.PropertyEditing.Windows
 {
 	internal class CategoryExpander
-		: Expander
+		: FilterExpander
 	{
-		public CategoryExpander ()
-		{
-			DataContextChanged += OnDataContextChanged;
-		}
-
-		public static readonly DependencyProperty IsFilteredProperty = DependencyProperty.Register (
-			"IsFiltered", typeof(bool), typeof(CategoryExpander), new PropertyMetadata (false, (o, args) => ((CategoryExpander)o).OnIsFilteredChanged()));
-
-		public bool IsFiltered
-		{
-			get { return (bool) GetValue (IsFilteredProperty); }
-			set { SetValue (IsFilteredProperty, value); }
-		}
-
-		public override void OnApplyTemplate ()
-		{
-			base.OnApplyTemplate ();
-			UpdateValue();
-		}
-
 		protected override void OnExpanded ()
 		{
 			base.OnExpanded ();
@@ -62,58 +36,29 @@ protected override void OnKeyDown (KeyEventArgs e)
 			base.OnKeyDown (e);
 		}
 
-		private bool fromFilter;
-		private PanelViewModel panelVm;
-
-		private void UpdateValue ()
+		protected override void UpdateValue ()
 		{
-			if (this.panelVm == null)
+			if (ViewModel == null)
 				return;
 
-			SetCurrentValue (IsExpandedProperty, IsFiltered || this.panelVm.GetIsExpanded (Header as string));
+			SetCurrentValue (IsExpandedProperty, IsFiltered || ViewModel.GetIsExpanded (Header as string));
 		}
 
-		private void OnIsFilteredChanged ()
+		protected override void OnIsFilteredChanged ()
 		{
 			this.fromFilter = true;
-			UpdateValue ();
+			base.OnIsFilteredChanged ();
 			this.fromFilter = false;
 		}
 
-		private void UpdateViewModel ()
-		{
-			FrameworkElement element = this;
-			while (element != null && !(element is ItemsControl)) {
-				element = VisualTreeHelper.GetParent (element) as FrameworkElement;
-			}
-
-			if (element == null) {
-				ClearValue (IsFilteredProperty);
-				this.panelVm = null;
-				return;
-			}
-
-			this.panelVm = element.DataContext as PanelViewModel;
-			if (this.panelVm == null)
-				throw new InvalidOperationException ("Couldn't find valid parent");
-
-			SetBinding (IsFilteredProperty, new Binding (nameof(PanelViewModel.IsFiltering)) {
-				Source = this.panelVm
-			});
-		}
+		private bool fromFilter;
 
 		private void SetExpanded (bool isExpanded)
 		{
 			if (this.fromFilter)
 				return;
 
-			this.panelVm.SetIsExpanded ((string) Header, isExpanded);
-		}
-
-		private void OnDataContextChanged (object sender, DependencyPropertyChangedEventArgs e)
-		{
-			UpdateViewModel();
-			UpdateValue();
+			ViewModel.SetIsExpanded ((string) Header, isExpanded);
 		}
     }
 }

Xamarin.PropertyEditing.Windows/FilterExpander.cs

@@ -0,0 +1,72 @@
+using System;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Data;
+using System.Windows.Media;
+using Xamarin.PropertyEditing.ViewModels;
+
+namespace Xamarin.PropertyEditing.Windows
+{
+	internal class FilterExpander
+		: Expander
+	{
+
+		public static readonly DependencyProperty IsFilteredProperty = DependencyProperty.Register (
+			"IsFiltered", typeof (bool), typeof (FilterExpander), new PropertyMetadata (false, (o, args) => ((FilterExpander)o).OnIsFilteredChanged ()));
+
+		public bool IsFiltered
+		{
+			get { return (bool)GetValue (IsFilteredProperty); }
+			set { SetValue (IsFilteredProperty, value); }
+		}
+
+		public override void OnApplyTemplate ()
+		{
+			base.OnApplyTemplate ();
+			UpdateViewModel();
+		}
+
+		protected PanelViewModel ViewModel
+		{
+			get;
+			private set;
+		}
+
+		protected virtual void UpdateValue ()
+		{
+			if (ViewModel == null)
+				return;
+
+			SetCurrentValue (IsExpandedProperty, IsFiltered);
+		}
+
+		protected virtual void OnIsFilteredChanged ()
+		{
+			UpdateValue ();
+		}
+
+		private void UpdateViewModel ()
+		{
+			FrameworkElement element = this;
+			while (element != null && !(element is ItemsControl)) {
+				element = VisualTreeHelper.GetParent (element) as FrameworkElement;
+			}
+
+			if (element == null) {
+				ClearValue (IsFilteredProperty);
+				ViewModel = null;
+				return;
+			}
+
+			ViewModel = element.DataContext as PanelViewModel;
+			if (ViewModel == null)
+				throw new InvalidOperationException ("Couldn't find valid parent");
+
+			SetBinding (IsFilteredProperty, new Binding (nameof (PanelViewModel.IsFiltering)) {
+				Source = ViewModel
+			});
+
+			UpdateValue();
+		}
+	}
+}

Xamarin.PropertyEditing.Windows/Themes/PropertyEditorPanelStyle.xaml

@@ -141,15 +141,15 @@
 						</ControlTemplate>
 					</ItemsControl.Template>
 				</ItemsControl>
-				<Expander Grid.Row="1" Visibility="{Binding HasUncommonElements,Converter={StaticResource BoolToVisibilityConverter}}" Style="{StaticResource AdvancedPropertiesExpander}">
+				<local:FilterExpander Grid.Row="1" Visibility="{Binding HasUncommonElements,Converter={StaticResource BoolToVisibilityConverter}}" Style="{StaticResource AdvancedPropertiesExpander}" IsExpanded="{Binding UncommonShown,Mode=TwoWay}">
 					<ItemsControl Grid.Row="0" Style="{StaticResource PropertyListStyle}" ItemsSource="{Binding UncommonEditors,Mode=OneTime}">
 						<ItemsControl.Template>
 							<ControlTemplate>
 								<ItemsPresenter />
 							</ControlTemplate>
 						</ItemsControl.Template>
 					</ItemsControl>
-				</Expander>
+				</local:FilterExpander>
 			</Grid>
 		</local:CategoryExpander>
 	</DataTemplate>

Xamarin.PropertyEditing.Windows/Xamarin.PropertyEditing.Windows.csproj

@@ -99,6 +99,7 @@
     <Compile Include="CurrentColorEditorControl.cs" />
     <Compile Include="DoubleToPercentageConverter.cs" />
     <Compile Include="DoubleToQuantityConverter.cs" />
+    <Compile Include="FilterExpander.cs" />
     <Compile Include="HasItemsToVisibilityConverter.cs" />
     <Compile Include="InvertedVisibilityConverter.cs" />
     <Compile Include="IPropertiesHost.cs" />