Flag valid measure status in iOS backing views to avoid repeat measur…

…ing (#12933) Co-authored-by: E.Z. Hart <hartez@gmail.com>
dotnet · Jan 30, 2023 · 9674a90 · 9674a90
1 parent e5ec60b
commit 9674a90
Show file tree

Hide file tree

Showing 4 changed files with 314 additions and 3 deletions.
diff --git a/src/Controls/tests/DeviceTests/Elements/ContentView/ContentViewTests.iOS.cs b/src/Controls/tests/DeviceTests/Elements/ContentView/ContentViewTests.iOS.cs
@@ -1,4 +1,10 @@
-using Microsoft.Maui.Handlers;
+using System.Threading.Tasks;
+using Microsoft.Maui.Graphics;
+using Microsoft.Maui.Controls;
+using Microsoft.Maui.Handlers;
+using Xunit;
+using Microsoft.Maui.Platform;
+using ContentView = Microsoft.Maui.Controls.ContentView;
 
 namespace Microsoft.Maui.DeviceTests
 {
@@ -13,5 +19,137 @@ static int GetContentChildCount(ContentViewHandler contentViewHandler)
 		{
 			return contentViewHandler.PlatformView.Subviews[0].Subviews.Length;
 		}
+
+		[Fact, Category(TestCategory.Layout)]
+		public async Task ContentViewHasExpectedSize()
+		{
+			var contentView = new ContentView();
+			var label = new Label { Text = "", HeightRequest = 100, WidthRequest = 100 };
+			contentView.Content = label;
+
+			var size = await InvokeOnMainThreadAsync(() =>
+			{
+				var labelHandler = CreateHandler<LabelHandler>(label);
+				var handler = CreateHandler<ContentViewHandler>(contentView);
+
+				var targetSize = handler.VirtualView.Measure(double.PositiveInfinity, double.PositiveInfinity);
+				handler.VirtualView.Arrange(new Rect(Point.Zero, targetSize));
+
+				return handler.PlatformView.Bounds.Size.ToSize();
+			});
+
+			Assert.Equal(100, size.Width);
+			Assert.Equal(100, size.Height);
+		}
+
+		[Fact, Category(TestCategory.Layout)]
+		public async Task ContentViewRespondsWhenViewAdded()
+		{
+			var contentView = new ContentView();
+			var label = new Label { Text = "", HeightRequest = 100, WidthRequest = 100 };
+
+			var size = await InvokeOnMainThreadAsync(() =>
+			{
+				var labelHandler = CreateHandler<LabelHandler>(label);
+				var handler = CreateHandler<ContentViewHandler>(contentView);
+
+				var targetSize = handler.VirtualView.Measure(double.PositiveInfinity, double.PositiveInfinity);
+				handler.VirtualView.Arrange(new Rect(Point.Zero, targetSize));
+
+				return handler.PlatformView.Bounds.Size.ToSize();
+			});
+
+			Assert.Equal(0, size.Width);
+			Assert.Equal(0, size.Height);
+
+			var updatedSize = await InvokeOnMainThreadAsync(() =>
+			{
+				var handler = CreateHandler<ContentViewHandler>(contentView);
+
+				contentView.Content = label;
+
+				var targetSize = handler.VirtualView.Measure(double.PositiveInfinity, double.PositiveInfinity);
+				handler.VirtualView.Arrange(new Rect(Point.Zero, targetSize));
+
+				return handler.PlatformView.Bounds.Size.ToSize();
+			});
+
+			Assert.Equal(100, updatedSize.Width);
+			Assert.Equal(100, updatedSize.Height);
+		}
+
+		[Fact, Category(TestCategory.Layout)]
+		public async Task ContentViewRespondsWhenViewRemoved()
+		{
+			var contentView = new ContentView();
+			var label = new Label { Text = "", HeightRequest = 100, WidthRequest = 100 };
+			contentView.Content = label;
+
+			var size = await InvokeOnMainThreadAsync(() =>
+			{
+				var labelHandler = CreateHandler<LabelHandler>(label);
+				var handler = CreateHandler<ContentViewHandler>(contentView);
+
+				var targetSize = handler.VirtualView.Measure(double.PositiveInfinity, double.PositiveInfinity);
+				handler.VirtualView.Arrange(new Rect(Point.Zero, targetSize));
+
+				return handler.PlatformView.Bounds.Size.ToSize();
+			});
+
+			Assert.Equal(100, size.Width);
+			Assert.Equal(100, size.Height);
+
+			var updatedSize = await InvokeOnMainThreadAsync(() =>
+			{
+				var handler = CreateHandler<ContentViewHandler>(contentView);
+
+				contentView.Content = null;
+
+				var targetSize = handler.VirtualView.Measure(double.PositiveInfinity, double.PositiveInfinity);
+				handler.VirtualView.Arrange(new Rect(Point.Zero, targetSize));
+
+				return handler.PlatformView.Bounds.Size.ToSize();
+			});
+
+			Assert.Equal(0, updatedSize.Width);
+			Assert.Equal(0, updatedSize.Height);
+		}
+
+		[Fact, Category(TestCategory.Layout)]
+		public async Task ContentViewRespondsWhenViewUpdated()
+		{
+			var contentView = new ContentView();
+			var label = new Label { Text = "", HeightRequest = 100, WidthRequest = 100 };
+			contentView.Content = label;
+
+			var size = await InvokeOnMainThreadAsync(() =>
+			{
+				var labelHandler = CreateHandler<LabelHandler>(label);
+				var handler = CreateHandler<ContentViewHandler>(contentView);
+
+				var targetSize = handler.VirtualView.Measure(double.PositiveInfinity, double.PositiveInfinity);
+				handler.VirtualView.Arrange(new Rect(Point.Zero, targetSize));
+
+				return handler.PlatformView.Bounds.Size.ToSize();
+			});
+
+			Assert.Equal(100, size.Width);
+			Assert.Equal(100, size.Height);
+
+			var updatedSize = await InvokeOnMainThreadAsync(() =>
+			{
+				var handler = CreateHandler<ContentViewHandler>(contentView);
+
+				label.HeightRequest = 300;
+
+				var targetSize = handler.VirtualView.Measure(double.PositiveInfinity, double.PositiveInfinity);
+				handler.VirtualView.Arrange(new Rect(Point.Zero, targetSize));
+
+				return handler.PlatformView.Bounds.Size.ToSize();
+			});
+
+			Assert.Equal(100, updatedSize.Width);
+			Assert.Equal(300, updatedSize.Height);
+		}
 	}
 }
diff --git a/src/Controls/tests/DeviceTests/Elements/Layout/LayoutTests.iOS.cs b/src/Controls/tests/DeviceTests/Elements/Layout/LayoutTests.iOS.cs
@@ -0,0 +1,154 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Microsoft.Maui.Controls;
+using Microsoft.Maui.Graphics;
+using Microsoft.Maui.Handlers;
+using Microsoft.Maui.Platform;
+using Xunit;
+
+namespace Microsoft.Maui.DeviceTests
+{
+	public partial class LayoutTests
+	{
+		[Fact, Category(TestCategory.Layout)]
+		public async Task LayoutViewHasExpectedSize()
+		{
+			var layout = new VerticalStackLayout();
+			var label = new Label { Text = "", HeightRequest = 100, WidthRequest = 100 };
+			layout.Add(label);
+
+			var size = await InvokeOnMainThreadAsync(() =>
+			{
+				var labelHandler = CreateHandler<LabelHandler>(label);
+				var layoutHandler = CreateHandler<LayoutHandler>(layout);
+
+				var targetSize = layoutHandler.VirtualView.Measure(double.PositiveInfinity, double.PositiveInfinity);
+				layoutHandler.VirtualView.Arrange(new Rect(Point.Zero, targetSize));
+
+				return layoutHandler.PlatformView.Bounds.Size.ToSize();
+			});
+
+			Assert.Equal(100, size.Width);
+			Assert.Equal(100, size.Height);
+		}
+
+		[Fact, Category(TestCategory.Layout)]
+		public async Task LayoutViewRespondsWhenViewAdded()
+		{
+			var layout = new VerticalStackLayout();
+			var label = new Label { Text = "", HeightRequest = 100, WidthRequest = 100 };
+			var secondLabel = new Label { Text = "", HeightRequest = 100, WidthRequest = 100 };
+			layout.Add(label);
+
+			var size = await InvokeOnMainThreadAsync(() =>
+			{
+				var labelHandler = CreateHandler<LabelHandler>(label);
+				var layoutHandler = CreateHandler<LayoutHandler>(layout);
+
+				var targetSize = layoutHandler.VirtualView.Measure(double.PositiveInfinity, double.PositiveInfinity);
+				layoutHandler.VirtualView.Arrange(new Rect(Point.Zero, targetSize));
+
+				return layoutHandler.PlatformView.Bounds.Size.ToSize();
+			});
+
+			Assert.Equal(100, size.Width);
+			Assert.Equal(100, size.Height);
+
+			var updatedSize = await InvokeOnMainThreadAsync(() =>
+			{
+				var labelHandler2 = CreateHandler<LabelHandler>(secondLabel);
+				var layoutHandler = CreateHandler<LayoutHandler>(layout);
+
+				layout.Add(secondLabel);
+
+				var targetSize = layoutHandler.VirtualView.Measure(double.PositiveInfinity, double.PositiveInfinity);
+				layoutHandler.VirtualView.Arrange(new Rect(Point.Zero, targetSize));
+
+				return layoutHandler.PlatformView.Bounds.Size.ToSize();
+			});
+
+			Assert.Equal(100, updatedSize.Width);
+			Assert.Equal(200, updatedSize.Height);
+		}
+
+		[Fact, Category(TestCategory.Layout)]
+		public async Task LayoutViewRespondsWhenViewRemoved()
+		{
+			var layout = new VerticalStackLayout();
+			var label = new Label { Text = "", HeightRequest = 100, WidthRequest = 100 };
+			var secondLabel = new Label { Text = "", HeightRequest = 100, WidthRequest = 100 };
+			layout.Add(label);
+			layout.Add(secondLabel);
+
+			var size = await InvokeOnMainThreadAsync(() =>
+			{
+				var labelHandler = CreateHandler<LabelHandler>(label);
+				var labelHandler2 = CreateHandler<LabelHandler>(secondLabel);
+				var layoutHandler = CreateHandler<LayoutHandler>(layout);
+
+				var targetSize = layoutHandler.VirtualView.Measure(double.PositiveInfinity, double.PositiveInfinity);
+				layoutHandler.VirtualView.Arrange(new Rect(Point.Zero, targetSize));
+
+				return layoutHandler.PlatformView.Bounds.Size.ToSize();
+			});
+
+			Assert.Equal(100, size.Width);
+			Assert.Equal(200, size.Height);
+
+			var updatedSize = await InvokeOnMainThreadAsync(() =>
+			{
+				var layoutHandler = CreateHandler<LayoutHandler>(layout);
+
+				layout.Remove(secondLabel);
+
+				var targetSize = layoutHandler.VirtualView.Measure(double.PositiveInfinity, double.PositiveInfinity);
+				layoutHandler.VirtualView.Arrange(new Rect(Point.Zero, targetSize));
+
+				return layoutHandler.PlatformView.Bounds.Size.ToSize();
+			});
+
+			Assert.Equal(100, updatedSize.Width);
+			Assert.Equal(100, updatedSize.Height);
+		}
+
+		[Fact, Category(TestCategory.Layout)]
+		public async Task LayoutViewRespondsWhenViewUpdated()
+		{
+			var layout = new VerticalStackLayout();
+			var label = new Label { Text = "", HeightRequest = 100, WidthRequest = 100 };
+			layout.Add(label);
+
+			var size = await InvokeOnMainThreadAsync(() =>
+			{
+				var labelHandler = CreateHandler<LabelHandler>(label);
+				var layoutHandler = CreateHandler<LayoutHandler>(layout);
+
+				var targetSize = layoutHandler.VirtualView.Measure(double.PositiveInfinity, double.PositiveInfinity);
+				layoutHandler.VirtualView.Arrange(new Rect(Point.Zero, targetSize));
+
+				return layoutHandler.PlatformView.Bounds.Size.ToSize();
+			});
+
+			Assert.Equal(100, size.Width);
+			Assert.Equal(100, size.Height);
+
+			var updatedSize = await InvokeOnMainThreadAsync(() =>
+			{
+				var layoutHandler = CreateHandler<LayoutHandler>(layout);
+
+				label.HeightRequest = 300;
+
+				var targetSize = layoutHandler.VirtualView.Measure(double.PositiveInfinity, double.PositiveInfinity);
+				layoutHandler.VirtualView.Arrange(new Rect(Point.Zero, targetSize));
+
+				return layoutHandler.PlatformView.Bounds.Size.ToSize();
+			});
+
+			Assert.Equal(100, updatedSize.Width);
+			Assert.Equal(300, updatedSize.Height);
+		}
+	}
+}
diff --git a/src/Core/src/Platform/iOS/ContentView.cs b/src/Core/src/Platform/iOS/ContentView.cs
@@ -11,6 +11,7 @@ public class ContentView : MauiView
 		WeakReference<IBorderStroke>? _clip;
 		CAShapeLayer? _childMaskLayer;
 		internal event EventHandler? LayoutSubviewsChanged;
+		bool _measureValid;
 
 		public override CGSize SizeThatFits(CGSize size)
 		{
@@ -23,6 +24,7 @@ public override CGSize SizeThatFits(CGSize size)
 			var height = size.Height;
 
 			var crossPlatformSize = CrossPlatformMeasure(width, height);
+			_measureValid = true;
 
 			return crossPlatformSize.ToCGSize();
 		}
@@ -33,7 +35,12 @@ public override void LayoutSubviews()
 
 			var bounds = AdjustForSafeArea(Bounds).ToRectangle();
 
-			CrossPlatformMeasure?.Invoke(bounds.Width, bounds.Height);
+			if (!_measureValid)
+			{
+				CrossPlatformMeasure?.Invoke(bounds.Width, bounds.Height);
+				_measureValid = true;
+			}
+
 			CrossPlatformArrange?.Invoke(bounds);
 
 			if (ChildMaskLayer != null)
@@ -46,6 +53,7 @@ public override void LayoutSubviews()
 
 		public override void SetNeedsLayout()
 		{
+			_measureValid = false;
 			base.SetNeedsLayout();
 			Superview?.SetNeedsLayout();
 		}

diff --git a/src/Core/src/Platform/iOS/LayoutView.cs b/src/Core/src/Platform/iOS/LayoutView.cs
@@ -8,6 +8,7 @@ namespace Microsoft.Maui.Platform
 	public class LayoutView : MauiView
 	{
 		bool _userInteractionEnabled;
+		bool _measureValid;
 
 		// TODO: Possibly reconcile this code with ViewHandlerExtensions.MeasureVirtualView
 		// If you make changes here please review if those changes should also
@@ -23,6 +24,7 @@ public override CGSize SizeThatFits(CGSize size)
 			var height = size.Height;
 
 			var crossPlatformSize = CrossPlatformMeasure(width, height);
+			_measureValid = true;
 
 			return crossPlatformSize.ToCGSize();
 		}
@@ -35,24 +37,33 @@ public override void LayoutSubviews()
 			base.LayoutSubviews();
 
 			var bounds = AdjustForSafeArea(Bounds).ToRectangle();
-			CrossPlatformMeasure?.Invoke(bounds.Width, bounds.Height);
+
+			if (!_measureValid)
+			{
+				CrossPlatformMeasure?.Invoke(bounds.Width, bounds.Height);
+				_measureValid = true;
+			}
+
 			CrossPlatformArrange?.Invoke(bounds);
 		}
 
 		public override void SetNeedsLayout()
 		{
+			_measureValid = false;
 			base.SetNeedsLayout();
 			Superview?.SetNeedsLayout();
 		}
 
 		public override void SubviewAdded(UIView uiview)
 		{
+			_measureValid = false;
 			base.SubviewAdded(uiview);
 			Superview?.SetNeedsLayout();
 		}
 
 		public override void WillRemoveSubview(UIView uiview)
 		{
+			_measureValid = false;
 			base.WillRemoveSubview(uiview);
 			Superview?.SetNeedsLayout();
 		}