feat(fillrule): Correctly implement FillRule for iOS & macOS

Author: carldebilly

src/Uno.UI/UI/Xaml/Media/FillRuleExtensions.iOSmacOS.cs

@@ -0,0 +1,14 @@
+using Windows.UI.Xaml.Media;
+using CoreAnimation;
+using Foundation;
+
+namespace Uno.UI.UI.Xaml.Media
+{
+	internal static class FillRuleExtensions
+	{
+		internal static NSString ToCAShapeLayerFillRule(this FillRule fillRule)
+		{
+			return fillRule == FillRule.EvenOdd ? CAShapeLayer.FillRuleEvenOdd : CAShapeLayer.FillRuleNonZero;
+		}
+	}
+}

src/Uno.UI/UI/Xaml/Shapes/Path.iOSmacOS.cs

@@ -11,15 +11,16 @@ public partial class Path : Shape
 
 		/// <inheritdoc />
 		protected override Size MeasureOverride(Size availableSize)
-			=> MeasureAbsoluteShape(availableSize, GetPath());
+			=> MeasureAbsoluteShape(availableSize, GetPathAndFillRule(out _));
 
 		/// <inheritdoc />
 		protected override Size ArrangeOverride(Size finalSize)
-			=> ArrangeAbsoluteShape(finalSize, GetPath());
+			=> ArrangeAbsoluteShape(finalSize, GetPathAndFillRule(out var fillRule), fillRule);
 
-		private CGPath GetPath()
+		private CGPath GetPathAndFillRule(out FillRule fillRule)
 		{
 			var streamGeometry = Data?.ToStreamGeometry();
+			fillRule = streamGeometry?.FillRule ?? FillRule.EvenOdd;
 			return streamGeometry?.ToCGPath();
 		}
 	}

src/Uno.UI/UI/Xaml/Shapes/Shape.iOSmacOS.cs

@@ -7,6 +7,7 @@
 using Uno.Extensions;
 using Uno.Logging;
 using Uno.UI;
+using Uno.UI.UI.Xaml.Media;
 using static System.Double;
 
 #if __IOS__
@@ -37,7 +38,7 @@ public Shape()
 
 
 		#region Rendering (Native)
-		private protected void Render(CGPath path)
+		private protected void Render(CGPath path, FillRule fillRule = FillRule.EvenOdd)
 		{
 			// Remove the old layer if any
 			_shapeLayer?.RemoveFromSuperLayer();
@@ -49,7 +50,7 @@ private protected void Render(CGPath path)
 				return;
 			}
 
-			_shapeLayer = CreateLayer(path);
+			_shapeLayer = CreateLayer(path, fillRule);
 			Layer.AddSublayer(_shapeLayer);
 		}
 
@@ -132,9 +133,9 @@ void RemoveSublayers()
 			}
 		}
 
-		private CAShapeLayer CreateLayer(CGPath path)
+		private CAShapeLayer CreateLayer(CGPath path, FillRule fillRule)
 		{
-			var pathLayer = new CAShapeLayer() { Path = path };
+			var pathLayer = new CAShapeLayer() { Path = path, FillRule = fillRule.ToCAShapeLayerFillRule()};
 
 			SetFillAndStroke(pathLayer);
 

src/Uno.UI/UI/Xaml/Shapes/Shape.layout.cs

@@ -328,7 +328,7 @@ private protected Size MeasureAbsoluteShape(Size availableSize, NativePath path)
 			return size;
 		}
 
-		private protected Size ArrangeAbsoluteShape(Size finalSize, NativePath path)
+		private protected Size ArrangeAbsoluteShape(Size finalSize, NativePath path, FillRule fillRule = FillRule.EvenOdd)
 		{
 			if (path == null)
 			{
@@ -536,7 +536,7 @@ private protected Size ArrangeAbsoluteShape(Size finalSize, NativePath path)
 
 			var renderPath = new CoreGraphics.CGPath(path, renderTransform);
 
-			Render(renderPath);
+			Render(renderPath, fillRule);
 #if __IOS__
 			// If the Shape does not have size defined, and natural size of the geometry is lower than the finalSize,
 			// then we don't clip the shape!