Clip Border content based on StrokeShape property

dotnet · Jun 23, 2022 · d4707e6 · d4707e6
1 parent 1585906
commit d4707e6
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Showing 4 changed files with 103 additions and 1 deletion.
diff --git a/src/Core/src/Platform/iOS/ContentView.cs b/src/Core/src/Platform/iOS/ContentView.cs
@@ -1,11 +1,16 @@
 using System;
+using CoreAnimation;
 using CoreGraphics;
 using Microsoft.Maui.Graphics;
+using Microsoft.Maui.Graphics.Platform;
 
 namespace Microsoft.Maui.Platform
 {
-	public class ContentView : MauiView
+	public class ContentView : MauiView, IDisposable
 	{
+		IBorderStroke? _clip;
+		CAShapeLayer? _childMaskLayer;
+
 		public override CGSize SizeThatFits(CGSize size)
 		{
 			if (CrossPlatformMeasure == null)
@@ -29,6 +34,11 @@ public override void LayoutSubviews()
 
 			CrossPlatformMeasure?.Invoke(bounds.Width, bounds.Height);
 			CrossPlatformArrange?.Invoke(bounds);
+
+			if (ChildMaskLayer != null)
+				ChildMaskLayer.Frame = bounds;
+
+			SetClip();
 		}
 
 		public override void SetNeedsLayout()
@@ -37,7 +47,90 @@ public override void SetNeedsLayout()
 			Superview?.SetNeedsLayout();
 		}
 
+		public new void Dispose()
+		{
+			DisposeClip();
+
+			base.Dispose();
+		}
+
 		internal Func<double, double, Size>? CrossPlatformMeasure { get; set; }
 		internal Func<Rect, Size>? CrossPlatformArrange { get; set; }
+
+		internal IBorderStroke? Clip
+		{
+			get { return _clip; }
+			set
+			{
+				_clip = value;
+
+				SetClip();
+			}
+		}
+
+		CAShapeLayer? ChildMaskLayer
+		{
+			get => _childMaskLayer;
+			set
+			{
+				var layer = GetChildLayer();
+
+				if (layer != null && _childMaskLayer != null)
+					layer.Mask = null;
+
+				_childMaskLayer = value;
+
+				if (layer != null)
+					layer.Mask = value;
+			}
+		}
+
+		CALayer? GetChildLayer()
+		{
+			if (Subviews.Length == 0)
+				return null;
+
+			var child = Subviews[0];
+
+			if (child.Layer == null || child.Layer.Sublayers == null)
+				return null;
+
+			return child.Layer;
+		}
+
+		void DisposeClip()
+		{
+			if (Subviews.Length == 0)
+				return;
+
+			var mask = ChildMaskLayer;
+
+			if (mask == null && Clip == null)
+				return;
+
+			ChildMaskLayer = null;
+		}
+
+		void SetClip()
+		{
+			if (Subviews.Length == 0)
+				return;
+
+			var mask = ChildMaskLayer;
+
+			if (mask == null && Clip == null)
+				return;
+
+			mask ??= ChildMaskLayer = new CAShapeLayer();
+
+			var frame = Frame;
+
+			var bounds = new RectF(0, 0, (float)frame.Width, (float)frame.Height);
+
+			IShape? clipShape = Clip?.Shape;
+			var path = clipShape?.PathForBounds(bounds);
+			var nativePath = path?.AsCGPath();
+			mask.Path = nativePath;
+		}
 	}
 }
diff --git a/src/Core/src/Platform/iOS/StrokeExtensions.cs b/src/Core/src/Platform/iOS/StrokeExtensions.cs
@@ -125,21 +125,28 @@ internal static void UpdateMauiCALayer(this UIView platformView, IBorderStroke?
 			if (backgroundLayer is MauiCALayer mauiCALayer)
 			{
 				backgroundLayer.Frame = platformView.Bounds;
+
 				if (border is IView v)
 					mauiCALayer.SetBackground(v.Background);
 				else
 					mauiCALayer.SetBackground(new SolidPaint(Colors.Transparent));
+
 				mauiCALayer.SetBorderBrush(border?.Stroke);
 				mauiCALayer.SetBorderWidth(border?.StrokeThickness ?? 0);
 				mauiCALayer.SetBorderDash(border?.StrokeDashPattern, border?.StrokeDashOffset ?? 0);
 				mauiCALayer.SetBorderMiterLimit(border?.StrokeMiterLimit ?? 0);
+
 				if (border != null)
 				{
 					mauiCALayer.SetBorderLineJoin(border.StrokeLineJoin);
 					mauiCALayer.SetBorderLineCap(border.StrokeLineCap);
 				}
+
 				mauiCALayer.SetBorderShape(border?.Shape);
 			}
+
+			if (platformView is ContentView contentView)
+				contentView.Clip = border;
 		}
 	}
 }
diff --git a/src/Core/src/PublicAPI/net-ios/PublicAPI.Unshipped.txt b/src/Core/src/PublicAPI/net-ios/PublicAPI.Unshipped.txt
@@ -1,4 +1,5 @@
 #nullable enable
+Microsoft.Maui.Platform.ContentView.Dispose() -> void
 override Microsoft.Maui.Platform.ContentView.SetNeedsLayout() -> void
 override Microsoft.Maui.Platform.LayoutView.HitTest(CoreGraphics.CGPoint point, UIKit.UIEvent? uievent) -> UIKit.UIView!
 override Microsoft.Maui.Platform.LayoutView.SetNeedsLayout() -> void

diff --git a/src/Core/src/PublicAPI/net-maccatalyst/PublicAPI.Unshipped.txt b/src/Core/src/PublicAPI/net-maccatalyst/PublicAPI.Unshipped.txt
@@ -1,4 +1,5 @@
 #nullable enable
+Microsoft.Maui.Platform.ContentView.Dispose() -> void
 override Microsoft.Maui.Platform.ContentView.SetNeedsLayout() -> void
 override Microsoft.Maui.Platform.LayoutView.HitTest(CoreGraphics.CGPoint point, UIKit.UIEvent? uievent) -> UIKit.UIView!
 override Microsoft.Maui.Platform.LayoutView.SetNeedsLayout() -> void