Adding UI Test for the condition

MaterialDesignThemes.UITests/WPF/ContentControls/ContentControlTests.cs

@@ -0,0 +1,43 @@
+using System.ComponentModel;
+
+namespace MaterialDesignThemes.UITests.WPF.ContentControls;
+
+public class ContentControlTests : TestBase
+{
+    public ContentControlTests(ITestOutputHelper output)
+           : base(output)
+    {
+    }
+
+
+    [Fact]
+    [Description("Issue 2510")]
+    public async Task ClearButton_InsideOfControlTemplate_CanStillClearContent()
+    {
+        await using var recorder = new TestRecorder(App);
+
+        //Arrange
+        var grid = await LoadXaml<ContentControl>(@"
+<ContentControl>
+  <ContentControl.ContentTemplate>
+    <DataTemplate>
+      <TextBox Text=""Some Text"" materialDesign:TextFieldAssist.HasClearButton=""True""/>
+    </DataTemplate>
+  </ContentControl.ContentTemplate>
+</ContentControl>");
+        var textBox = await grid.GetElement<TextBox>("/TextBox");
+        var clearButton = await grid.GetElement<Button>("PART_ClearButton");
+
+        string? initial = await textBox.GetText();
+
+        //Act
+        await clearButton.LeftClick();
+
+        //Assert
+        Assert.Equal("Some Text", initial);
+        Assert.True(string.IsNullOrEmpty(await textBox.GetText()));
+
+        recorder.Success();
+    }
+
+}

MaterialDesignThemes.Wpf/Internal/ClearText.cs

@@ -1,59 +1,58 @@
-namespace MaterialDesignThemes.Wpf.Internal
+namespace MaterialDesignThemes.Wpf.Internal;
+
+public static class ClearText
 {
-    public static class ClearText
-    {
-        public static readonly RoutedCommand ClearCommand = new();
+    public static readonly RoutedCommand ClearCommand = new();
 
-        public static bool GetHandlesClearCommand(DependencyObject obj)
-            => (bool)obj.GetValue(HandlesClearCommandProperty);
+    public static bool GetHandlesClearCommand(DependencyObject obj)
+        => (bool)obj.GetValue(HandlesClearCommandProperty);
 
-        public static void SetHandlesClearCommand(DependencyObject obj, bool value)
-            => obj.SetValue(HandlesClearCommandProperty, value);
+    public static void SetHandlesClearCommand(DependencyObject obj, bool value)
+        => obj.SetValue(HandlesClearCommandProperty, value);
 
-        public static readonly DependencyProperty HandlesClearCommandProperty =
-            DependencyProperty.RegisterAttached("HandlesClearCommand", typeof(bool), typeof(ClearText), new PropertyMetadata(false, OnHandlesClearCommandChanged));
+    public static readonly DependencyProperty HandlesClearCommandProperty =
+        DependencyProperty.RegisterAttached("HandlesClearCommand", typeof(bool), typeof(ClearText), new PropertyMetadata(false, OnHandlesClearCommandChanged));
 
-        private static void OnHandlesClearCommandChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
+    private static void OnHandlesClearCommandChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
+    {
+        if (d is UIElement element)
         {
-            if (d is UIElement element)
+            if ((bool)e.NewValue)
             {
-                if ((bool)e.NewValue)
-                {
-                    element.CommandBindings.Add(new CommandBinding(ClearCommand, OnClearCommand));
-                }
-                else
+                element.CommandBindings.Add(new CommandBinding(ClearCommand, OnClearCommand));
+            }
+            else
+            {
+                for (int i = element.CommandBindings.Count - 1; i >= 0; i--)
                 {
-                    for (int i = element.CommandBindings.Count - 1; i >= 0; i--)
+                    if (element.CommandBindings[i].Command == ClearCommand)
                     {
-                        if (element.CommandBindings[i].Command == ClearCommand)
-                        {
-                            element.CommandBindings.RemoveAt(i);
-                        }
+                        element.CommandBindings.RemoveAt(i);
                     }
                 }
             }
+        }
 
-            static void OnClearCommand(object sender, ExecutedRoutedEventArgs e)
+        static void OnClearCommand(object sender, ExecutedRoutedEventArgs e)
+        {
+            switch (sender)
             {
-                switch (sender)
-                {
-                    case DatePicker datePicker:
-                        datePicker.SetCurrentValue(DatePicker.SelectedDateProperty, null);
-                        break;
-                    case TextBox textBox:
-                        textBox.SetCurrentValue(TextBox.TextProperty, null);
-                        break;
-                    case ComboBox comboBox:
-                        comboBox.SetCurrentValue(ComboBox.TextProperty, null);
-                        comboBox.SetCurrentValue(Selector.SelectedItemProperty, null);
-                        break;
-                    case PasswordBox passwordBox:
-                        passwordBox.Password = null;
-                        break;
-                }
-                e.Handled = true;
+                case DatePicker datePicker:
+                    datePicker.SetCurrentValue(DatePicker.SelectedDateProperty, null);
+                    break;
+                case TextBox textBox:
+                    textBox.SetCurrentValue(TextBox.TextProperty, null);
+                    break;
+                case ComboBox comboBox:
+                    comboBox.SetCurrentValue(ComboBox.TextProperty, null);
+                    comboBox.SetCurrentValue(Selector.SelectedItemProperty, null);
+                    break;
+                case PasswordBox passwordBox:
+                    passwordBox.Password = null;
+                    break;
             }
+            e.Handled = true;
         }
-
     }
+
 }