feat: add new class inheritance mechanism.

demo/Ursa.Demo/Pages/AutoCompleteBoxDemo.axaml

@@ -10,7 +10,7 @@
              x:Class="Ursa.Demo.Pages.AutoCompleteBoxDemo">
     <StackPanel HorizontalAlignment="Left" Spacing="20">
         <StackPanel.Styles>
-            <Style Selector="AutoCompleteBox">
+            <Style Selector="u|AutoCompleteBox">
                 <Setter Property="Width" Value="300" />
                 <Setter Property="ItemsSource">
                     <Binding Path="States" />
@@ -25,6 +25,7 @@
 
         <u:AutoCompleteBox
             Watermark="Please select a State"
+            Classes="ClearButton"
             ValueMemberBinding="{ReflectionBinding Name}" />
         <u:AutoCompleteBox
             Classes="Large"
@@ -43,6 +44,5 @@
             InnerLeftContent="https://"
             InnerRightContent=".com"
             ValueMemberBinding="{ReflectionBinding Name}" />
-
     </StackPanel>
 </UserControl>

src/Ursa.Themes.Semi/Behaviors/ClassHelper.cs

@@ -1,25 +1,69 @@
-using Avalonia;
+using System.Collections.Specialized;
+using Avalonia;
+using Avalonia.Collections;
 
 namespace Ursa.Themes.Semi;
 
 internal class ClassHelper : AvaloniaObject
 {
-    static ClassHelper()
-    {
-        ClassesProperty.Changed.AddClassHandler<StyledElement>(OnClassesChanged);
-    }
-    
     public static readonly AttachedProperty<string> ClassesProperty =
         AvaloniaProperty.RegisterAttached<ClassHelper, StyledElement, string>("Classes");
 
-    public static void SetClasses(AvaloniaObject obj, string value) => obj.SetValue(ClassesProperty, value);
+    public static readonly AttachedProperty<StyledElement> ClassSourceProperty =
-    public static string GetClasses(AvaloniaObject obj) => obj.GetValue(ClassesProperty);
+        AvaloniaProperty.RegisterAttached<ClassHelper, StyledElement, StyledElement>("ClassSource");
+
+    static ClassHelper()
+    {
+        ClassesProperty.Changed.AddClassHandler<StyledElement>(OnClassesChanged);
+        ClassSourceProperty.Changed.AddClassHandler<StyledElement>(OnClassSourceChanged);
+    }
+
+    private static void OnClassSourceChanged(StyledElement arg1, AvaloniaPropertyChangedEventArgs arg2)
+    {
+        if (arg2.NewValue is StyledElement styledElement)
+        {
+            arg1.Classes.Clear();
+            var nonPseudoClasses = styledElement.Classes.Where(c => !c.StartsWith(":"));
+            arg1.Classes.AddRange(nonPseudoClasses);
+            styledElement.Classes.WeakSubscribe((o, e) => OnSourceClassesChanged(o, e, arg1));
+        }
+    }
+
+    private static void OnSourceClassesChanged(object sender, NotifyCollectionChangedEventArgs e, StyledElement target)
+    {
+        if (sender is AvaloniaList<string> classes)
+        {
+            target.Classes.Clear();
+            var nonPseudoClasses = classes.Where(c => !c.StartsWith(":"));
+            target.Classes.AddRange(nonPseudoClasses);
+        }
+    }
+
+    public static void SetClasses(AvaloniaObject obj, string value)
+    {
+        obj.SetValue(ClassesProperty, value);
+    }
+
+    public static string GetClasses(AvaloniaObject obj)
+    {
+        return obj.GetValue(ClassesProperty);
+    }
 
     private static void OnClassesChanged(StyledElement sender, AvaloniaPropertyChangedEventArgs value)
     {
-        string? classes = value.GetNewValue<string?>();
+        var classes = value.GetNewValue<string?>();
         if (classes is null) return;
         sender.Classes.Clear();
         sender.Classes.Add(classes);
     }
+
+    public static void SetClassSource(StyledElement obj, StyledElement value)
+    {
+        obj.SetValue(ClassSourceProperty, value);
+    }
+
+    public static StyledElement GetClassSource(StyledElement obj)
+    {
+        return obj.GetValue(ClassSourceProperty);
+    }
 }

src/Ursa.Themes.Semi/Controls/AutoCompleteBox.axaml

@@ -0,0 +1,49 @@
+<ResourceDictionary
+    xmlns="https://github.com/avaloniaui"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:u="https://irihi.tech/ursa"
+    xmlns:usemi="https://irihi.tech/ursa/themes/semi">
+    <!--  Add Resources Here  -->
+    <ControlTheme x:Key="{x:Type u:AutoCompleteBox}" TargetType="u:AutoCompleteBox">
+        <Setter Property="VerticalAlignment" Value="Center" />
+        <Setter Property="MinHeight" Value="{DynamicResource AutoCompleteBoxDefaultHeight}" />
+        <Setter Property="MaxDropDownHeight" Value="{DynamicResource AutoCompleteMaxDropdownHeight}" />
+        <Setter Property="Template">
+            <ControlTemplate TargetType="AutoCompleteBox">
+                <Panel>
+                    <TextBox
+                        Name="PART_TextBox"
+                        MinHeight="{TemplateBinding MinHeight}"
+                        VerticalAlignment="Stretch"
+                        usemi:ClassHelper.ClassSource="{TemplateBinding}"
+                        DataValidationErrors.Errors="{TemplateBinding (DataValidationErrors.Errors)}"
+                        InnerLeftContent="{TemplateBinding InnerLeftContent}"
+                        InnerRightContent="{TemplateBinding InnerRightContent}"
+                        Watermark="{TemplateBinding Watermark}" />
+                    <Popup
+                        Name="PART_Popup"
+                        MinWidth="{Binding Bounds.Width, RelativeSource={RelativeSource TemplatedParent}}"
+                        MaxHeight="{TemplateBinding MaxDropDownHeight}"
+                        IsLightDismissEnabled="True"
+                        PlacementTarget="{TemplateBinding}">
+                        <Border
+                            Margin="{DynamicResource AutoCompleteBoxPopupMargin}"
+                            HorizontalAlignment="Stretch"
+                            Background="{DynamicResource AutoCompleteBoxPopupBackground}"
+                            BorderBrush="{DynamicResource AutoCompleteBoxPopupBorderBrush}"
+                            BorderThickness="{DynamicResource AutoCompleteBoxPopupBorderThickness}"
+                            BoxShadow="{DynamicResource AutoCompleteBoxPopupBoxShadow}"
+                            CornerRadius="{DynamicResource AutoCompleteBoxPopupCornerRadius}">
+                            <ListBox
+                                Name="PART_SelectingItemsControl"
+                                Foreground="{TemplateBinding Foreground}"
+                                ItemTemplate="{TemplateBinding ItemTemplate}"
+                                ScrollViewer.HorizontalScrollBarVisibility="Auto"
+                                ScrollViewer.VerticalScrollBarVisibility="Auto" />
+                        </Border>
+                    </Popup>
+                </Panel>
+            </ControlTemplate>
+        </Setter>
+    </ControlTheme>
+</ResourceDictionary>

src/Ursa.Themes.Semi/Controls/_index.axaml

@@ -1,6 +1,7 @@
 <ResourceDictionary xmlns="https://github.com/avaloniaui" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
     <!--  Add Resources Here  -->
     <ResourceDictionary.MergedDictionaries>
+        <ResourceInclude Source="AutoCompleteBox.axaml" />
         <ResourceInclude Source="Avatar.axaml" />
         <ResourceInclude Source="Badge.axaml" />
         <ResourceInclude Source="Banner.axaml" />

src/Ursa/Controls/AutoCompleteBox/AutoCompleteBox.cs

@@ -1,12 +1,15 @@
+using Avalonia.Controls;
+using Avalonia.Controls.Primitives;
 using Avalonia.Input;
 using Avalonia.Interactivity;
+using Irihi.Avalonia.Shared.Contracts;
 
 namespace Ursa.Controls;
 
-public class AutoCompleteBox: Avalonia.Controls.AutoCompleteBox
+public class AutoCompleteBox: Avalonia.Controls.AutoCompleteBox, IClearControl
 {
-    protected override Type StyleKeyOverride { get; } = typeof(Avalonia.Controls.AutoCompleteBox);
+    // protected override Type StyleKeyOverride { get; } = typeof(Avalonia.Controls.AutoCompleteBox);
-
+    private TextBox? _text;
     static AutoCompleteBox()
     {
         MinimumPrefixLengthProperty.OverrideDefaultValue<AutoCompleteBox>(0);
@@ -17,6 +20,12 @@ public class AutoCompleteBox: Avalonia.Controls.AutoCompleteBox
         this.AddHandler(PointerPressedEvent, OnBoxPointerPressed, RoutingStrategies.Tunnel);
     }
 
+    protected override void OnApplyTemplate(TemplateAppliedEventArgs e)
+    {
+        base.OnApplyTemplate(e);
+        _text = e.NameScope.Get<TextBox>("PART_TextBox");
+    }
+
     private void OnBoxPointerPressed(object? sender, PointerPressedEventArgs e)
     {
         if (Equals(sender, this) && e.GetCurrentPoint(this).Properties.IsLeftButtonPressed)
@@ -30,4 +39,9 @@ public class AutoCompleteBox: Avalonia.Controls.AutoCompleteBox
         base.OnGotFocus(e);
         SetCurrentValue(IsDropDownOpenProperty, true);
     }
+
+    public void Clear()
+    {
+        SetCurrentValue(SelectedItemProperty, null);
+    }
 }