feat: Add support for Scale property in CornerRadiusFilterConverter

src/Uno.UI/Microsoft/UI/Xaml/Controls/Primitives/CornerRadiusFilterConverter.cs

@@ -1,75 +1,133 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License. See LICENSE in the project root for license information.
+// MUX Reference CornerRadiusFilterConverter.cpp, commit 22e5052
+
+#nullable enable
+
+using System;
 using Windows.UI.Xaml;
 using Windows.UI.Xaml.Data;
 
-namespace Microsoft.UI.Xaml.Controls.Primitives
+namespace Microsoft.UI.Xaml.Controls.Primitives;
+
+/// <summary>
+/// Converts an existing CornerRadius struct to a new CornerRadius struct, with filters applied
+/// to extract only the specified fields, leaving the others set to 0.
+/// </summary>
+public partial class CornerRadiusFilterConverter : DependencyObject, IValueConverter
 {
-	public partial class CornerRadiusFilterConverter : DependencyObject, IValueConverter
+	/// <summary>
+	/// Gets or sets the type of the filter applied to the CornerRadiusFilterConverter.
+	/// </summary>
+	public CornerRadiusFilterKind Filter
 	{
-		public static DependencyProperty FilterProperty { get; } = DependencyProperty.Register(
-			nameof(Filter), typeof(CornerRadiusFilterKind), typeof(CornerRadiusFilterConverter), new FrameworkPropertyMetadata(CornerRadiusFilterKind.None));
+		get => (CornerRadiusFilterKind)GetValue(FilterProperty);
+		set => SetValue(FilterProperty, value);
+	}
 
-		public CornerRadiusFilterKind Filter
-		{
-			get => (CornerRadiusFilterKind)GetValue(FilterProperty);
-			set => SetValue(FilterProperty, value);
-		}
+	/// <summary>
+	/// Identifies the Filter dependency property.
+	/// </summary>
+	public static DependencyProperty FilterProperty { get; } =
+		DependencyProperty.Register(
+			nameof(Filter),
+			typeof(CornerRadiusFilterKind),
+			typeof(CornerRadiusFilterConverter),
+			new FrameworkPropertyMetadata(CornerRadiusFilterKind.None));
 
-		private static CornerRadius Convert(CornerRadius radius, CornerRadiusFilterKind filterKind)
-		{
-			var result = radius;
+	/// <summary>
+	/// Gets or sets the scale multiplier applied to the CornerRadiusFilterConverter.
+	/// </summary>
+	public double Scale
+	{
+		get => (double)GetValue(ScaleProperty);
+		set => SetValue(ScaleProperty, value);
+	}
 
-			switch (filterKind)
-			{
-				case CornerRadiusFilterKind.Top:
-					result.BottomLeft = 0;
-					result.BottomRight = 0;
-					break;
-				case CornerRadiusFilterKind.Right:
-					result.TopLeft = 0;
-					result.BottomLeft = 0;
-					break;
-				case CornerRadiusFilterKind.Bottom:
-					result.TopLeft = 0;
-					result.TopRight = 0;
-					break;
-				case CornerRadiusFilterKind.Left:
-					result.TopRight = 0;
-					result.BottomRight = 0;
-					break;
-			}
+	/// <summary>
+	/// Identifies the Scale dependency property.
+	/// </summary>
+	public static DependencyProperty ScaleProperty { get; } =
+		DependencyProperty.Register(
+			nameof(Scale),
+			typeof(double),
+			typeof(CornerRadiusFilterConverter),
+			new FrameworkPropertyMetadata(1.0));
 
-			return result;
+	private static CornerRadius Convert(CornerRadius radius, CornerRadiusFilterKind filterKind)
+	{
+		var result = radius;
+
+		switch (filterKind)
+		{
+			case CornerRadiusFilterKind.Top:
+				result.BottomLeft = 0;
+				result.BottomRight = 0;
+				break;
+			case CornerRadiusFilterKind.Right:
+				result.TopLeft = 0;
+				result.BottomLeft = 0;
+				break;
+			case CornerRadiusFilterKind.Bottom:
+				result.TopLeft = 0;
+				result.TopRight = 0;
+				break;
+			case CornerRadiusFilterKind.Left:
+				result.TopRight = 0;
+				result.BottomRight = 0;
+				break;
 		}
 
-		private static double GetDoubleValue(CornerRadius radius, CornerRadiusFilterKind filterKind)
-			=>
-				filterKind switch
-				{
-					CornerRadiusFilterKind.TopLeftValue => radius.TopLeft,
-					CornerRadiusFilterKind.BottomRightValue => radius.BottomRight,
-					_ => 0d
-				};
+		return result;
+	}
+
+	private static double GetDoubleValue(CornerRadius radius, CornerRadiusFilterKind filterKind) =>
+		filterKind switch
+		{
+			CornerRadiusFilterKind.TopLeftValue => radius.TopLeft,
+			CornerRadiusFilterKind.BottomRightValue => radius.BottomRight,
+			_ => 0d
+		};
 
-		public object Convert(object value, Type targetType, object parameter, string language)
+	/// <summary>
+	/// Converts the source CornerRadius by extracting only the fields specified
+	/// by the Filter and leaving others set to 0.
+	/// </summary>
+	/// <param name="value">The source CornerRadius being passed to the target.</param>
+	/// <param name="targetType">The type of the target property. Part of the IValueConverter.Convert interface method, but not used.</param>
+	/// <param name="parameter">An optional parameter to be used in the converter logic. Part of the IValueConverter.Convert interface method, but not used.</param>
+	/// <param name="language">The language of the conversion. Part of the IValueConverter.Convert interface method, but not used.</param>
+	/// <returns>The converted CornerRadius/double value to be passed to the target dependency property.</returns>
+	public object? Convert(object? value, Type targetType, object? parameter, string language)
+	{
+		if (value is CornerRadius cornerRadius)
 		{
-			var filter = Filter;
+			var scale = Scale;
+			if (!double.IsNaN(scale))
+			{
+				cornerRadius.TopLeft *= scale;
+				cornerRadius.TopRight *= scale;
+				cornerRadius.BottomLeft *= scale;
+				cornerRadius.BottomRight *= scale;
+			}
 
-			if (value is CornerRadius cornerRadius)
+			var filterType = Filter;
+			if (filterType == CornerRadiusFilterKind.TopLeftValue ||
+				filterType == CornerRadiusFilterKind.BottomRightValue)
 			{
-				if (filter == CornerRadiusFilterKind.TopLeftValue || filter == CornerRadiusFilterKind.BottomRightValue)
-				{
-					return GetDoubleValue(cornerRadius, filter);
-				}
-				return Convert(cornerRadius, filter);
+				return GetDoubleValue(cornerRadius, filterType);
 			}
 
-			return null;
+			return Convert(cornerRadius, filterType);
 		}
 
-		public object ConvertBack(object value, Type targetType, object parameter, string language) =>
-			throw new NotSupportedException();
+		return null;
 	}
+
+	/// <summary>
+	/// Not implemented.
+	/// </summary>
+	/// <exception cref="NotImplementedException">Always thrown when called.</exception>
+	public object? ConvertBack(object? value, Type targetType, object? parameter, string language) =>
+		throw new NotImplementedException();
 }