Fixing issue with the template selector not getting forwarded. (#3405)

Author: Keboo

MaterialDesignThemes.UITests/Samples/PopupBox/PopupBoxWithTemplateSelector.xaml

@@ -0,0 +1,28 @@
+<UserControl x:Class="MaterialDesignThemes.UITests.Samples.PopupBox.PopupBoxWithTemplateSelector"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
+             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
+             xmlns:local="clr-namespace:MaterialDesignThemes.UITests.Samples.PopupBox" xmlns:materialDesign="http://materialdesigninxaml.net/winfx/xaml/themes"
+             mc:Ignorable="d" 
+             d:DesignHeight="450" d:DesignWidth="800">
+  <UserControl.Resources>
+    <DataTemplate x:Key="OddTemplate">
+      <Border Background="Red" Width="10" Height="10" />
+    </DataTemplate>
+
+    <DataTemplate x:Key="EvenTemplate">
+      <Border Background="Blue" Width="10" Height="10" />
+    </DataTemplate>
+
+    <local:ColorTemplateSelector x:Key="ColorTemplateSelector"
+                                 OddTemplate="{StaticResource OddTemplate}"
+                                 EvenTemplate="{StaticResource EvenTemplate}" />
+  </UserControl.Resources>
+  <StackPanel>
+    <materialDesign:PopupBox
+      
+      ToggleContentTemplateSelector="{StaticResource ColorTemplateSelector}" x:Name="MyPopupBox"/>
+    <Button Content="Toggle" Click="Button_Click" />
+  </StackPanel>
+</UserControl>

MaterialDesignThemes.UITests/Samples/PopupBox/PopupBoxWithTemplateSelector.xaml.cs

@@ -0,0 +1,35 @@
+
+namespace MaterialDesignThemes.UITests.Samples.PopupBox;
+
+/// <summary>
+/// Interaction logic for PopupBoxWithTemplateSelector.xaml
+/// </summary>
+public partial class PopupBoxWithTemplateSelector : UserControl
+{
+    private int _counter;
+    public PopupBoxWithTemplateSelector()
+    {
+        InitializeComponent();
+        MyPopupBox.ToggleContent = _counter;
+    }
+
+    private void Button_Click(object sender, RoutedEventArgs e)
+    {
+        MyPopupBox.ToggleContent =  ++_counter;
+    }
+}
+
+public class ColorTemplateSelector : DataTemplateSelector
+{
+    public DataTemplate? OddTemplate { get; set; }
+    public DataTemplate? EvenTemplate { get; set; }
+
+    public override DataTemplate? SelectTemplate(object? item, DependencyObject container)
+    {
+        if (item is int intValue)
+        {
+            return intValue % 2 == 0 ? EvenTemplate : OddTemplate;
+        }
+        return null;
+    }
+}

MaterialDesignThemes.UITests/WPF/PopupBox/PopupBoxTests.cs

@@ -1,4 +1,6 @@
 using System.ComponentModel;
+using System.Windows.Media;
+using MaterialDesignThemes.UITests.Samples.PopupBox;
 
 namespace MaterialDesignThemes.UITests.WPF.PopupBox;
 
@@ -32,6 +34,34 @@ public async Task PopupBox_WithElevation_AppliesElevationToNestedCard(Elevation
         // Assert
         Assert.Equal(elevation, await card.GetProperty<Elevation?>(ElevationAssist.ElevationProperty));
 
+        recorder.Success();
+    }
+
+    [Fact]
+    public async Task PopupBox_WithContentTemplateSelector_ChangesContent()
+    {
+        await using var recorder = new TestRecorder(App);
+
+        //Arrange
+        IVisualElement grid = (await LoadUserControl<PopupBoxWithTemplateSelector>());
+
+        IVisualElement<Button> button = await grid.GetElement<Button>();
+        IVisualElement<Wpf.PopupBox> popupBox = await grid.GetElement<Wpf.PopupBox>();
+
+
+        // Assert
+        var border = await popupBox.GetElement<Border>();
+        Assert.Equal(Colors.Blue, await border.GetBackgroundColor());
+
+        await button.LeftClick();
+
+        await Wait.For(async () =>
+        {
+            border = await popupBox.GetElement<Border>();
+            Assert.Equal(Colors.Red, await border.GetBackgroundColor());
+        });
+
+
         recorder.Success();
     }
 }

MaterialDesignThemes.Wpf/Themes/MaterialDesignTheme.PopupBox.xaml

@@ -106,6 +106,7 @@
                                 VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"
                                 Content="{TemplateBinding Content}"
                                 ContentTemplate="{TemplateBinding ContentTemplate}"
+                                ContentTemplateSelector="{TemplateBinding ContentTemplateSelector}"
                                 Focusable="False"
                                 SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" />
                   </ControlTemplate>