feat: move classhelper to shared library.

src/Irihi.Avalonia.Shared.Public/Helpers/ClassHelper.cs

@@ -0,0 +1,65 @@
+using System.Collections.Specialized;
+using Avalonia;
+using Avalonia.Collections;
+
+namespace Irihi.Avalonia.Shared.Helpers;
+
+public class ClassHelper
+{
+    public static readonly AttachedProperty<string> ClassesProperty =
+        AvaloniaProperty.RegisterAttached<ClassHelper, StyledElement, string>("Classes");
+
+    public static readonly AttachedProperty<StyledElement> ClassSourceProperty =
+        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 not StyledElement styledElement) return;
+        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 not AvaloniaList<string> classes) return;
+        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)
+    {
+        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/Irihi.Avalonia.Shared.Public/Irihi.Avalonia.Shared.Public.projitems

@@ -22,6 +22,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)Converters\ResourceConverter.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Helpers\AvaloniaPropertyExtension.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Helpers\BindingExtension.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Helpers\ClassHelper.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Helpers\LogicalHelpers.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Helpers\MathHelpers.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Helpers\ObservableExtension.cs" />

test/Irihi.Avalonia.Shared.UnitTest.Public/Helpers/ClassHelperTests.cs

@@ -0,0 +1,86 @@
+using Avalonia.Controls;
+using Avalonia.Styling;
+using Irihi.Avalonia.Shared.Helpers;
+
+namespace Irihi.Avalonia.Shared.UnitTest.Helpers;
+
+public class ClassHelperTests
+{
+    [Fact]
+    public void ClassesProperty_Should_Set_And_Get_Value()
+    {
+        var control = new Button();
+        ClassHelper.SetClasses(control, "test-class");
+        Assert.Equal("test-class", ClassHelper.GetClasses(control));
+    }
+
+    [Fact]
+    public void ClassSourceProperty_Should_Set_And_Get_Value()
+    {
+        var sourceControl = new Button();
+        var targetControl = new Button();
+        ClassHelper.SetClassSource(targetControl, sourceControl);
+        Assert.Equal(sourceControl, ClassHelper.GetClassSource(targetControl));
+    }
+
+    [Fact]
+    public void OnClassSourceChanged_Should_Copy_Classes()
+    {
+        var sourceControl = new Button();
+        sourceControl.Classes.Add("source-class");
+        var targetControl = new Button();
+        ClassHelper.SetClassSource(targetControl, sourceControl);
+        Assert.Contains("source-class", targetControl.Classes);
+    }
+
+    [Fact]
+    public void OnClassSourceChanged_Should_Not_Copy_PseudoClasses()
+    {
+        var sourceControl = new Button();
+        IPseudoClasses pseudoClasses = sourceControl.Classes;
+        pseudoClasses.Add(":pseudo-class");
+        var targetControl = new Button();
+        ClassHelper.SetClassSource(targetControl, sourceControl);
+        Assert.DoesNotContain(":pseudo-class", targetControl.Classes);
+    }
+
+    [Fact]
+    public void OnClassesChanged_Should_Update_Classes()
+    {
+        var control = new Button();
+        ClassHelper.SetClasses(control, "initial-class");
+        ClassHelper.SetClasses(control, "updated-class");
+        Assert.Contains("updated-class", control.Classes);
+        Assert.DoesNotContain("initial-class", control.Classes);
+    }
+
+    [Fact]
+    public void OnSourceClassesChanged_Should_Update_Target_Classes()
+    {
+        var sourceControl = new Button();
+        var targetControl = new Button();
+        ClassHelper.SetClassSource(targetControl, sourceControl);
+        sourceControl.Classes.Add("new-class");
+        Assert.Contains("new-class", targetControl.Classes);
+    }
+
+    [Fact]
+    public void OnClassesChanged_Should_Not_Remove_PseudoClasses()
+    {
+        var control = new Button();
+        IPseudoClasses pseudoClasses = control.Classes;
+        pseudoClasses.Add(":pseudo-class");
+        pseudoClasses.Add(":pseudo-class2");
+        ClassHelper.SetClasses(control, "initial-class");
+        Assert.Contains(":pseudo-class", control.Classes);
+        Assert.Contains(":pseudo-class2", control.Classes);
+    }
+
+    [Fact]
+    public void ClassesProperty_Should_Not_Throw_Exception_When_Null()
+    {
+        var control = new Button();
+        ClassHelper.SetClasses(control, null);
+        Assert.Null(ClassHelper.GetClasses(control));
+    }
+}

test/Irihi.Avalonia.Shared.UnitTest.Public/Irihi.Avalonia.Shared.UnitTest.Public.projitems

@@ -17,6 +17,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)Helpers\AffectsPseudoClassTests.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Helpers\AvaloniaPropertyExtensionTest.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Helpers\BindingExtensionTest.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Helpers\ClassHelperTests.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Helpers\LogicalHelpersTest.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Helpers\MathHelperTests.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Helpers\ObservableExtensionTest.cs" />