- add tests and fix mappers

src/Controls/src/Core/Border/Border.Mapper.cs

@@ -0,0 +1,18 @@
+#nullable disable
+using System;
+using Microsoft.Maui.Controls.Compatibility;
+using Microsoft.Maui.Handlers;
+
+namespace Microsoft.Maui.Controls
+{
+ public partial class Border
+ {
+ internal static new void RemapForControls()
+ {
+ // Ideally we wouldn't need these and we could create a cross cutting modify at the VisualElement level
+ // But we can't currently do that with mappers
+ BorderHandler.Mapper.ModifyMapping<IBorderView, IBorderHandler>(nameof(IView.Width), MapWidthOrHeight);
+ BorderHandler.Mapper.ModifyMapping<IBorderView, IBorderHandler>(nameof(IView.Height), MapWidthOrHeight);
+ }
+ }
+}

src/Controls/src/Core/Border/Border.cs

@@ -10,7 +10,7 @@
 namespace Microsoft.Maui.Controls
 {
  [ContentProperty(nameof(Content))]
- public class Border : View, IContentView, IBorderView, IPaddingElement
+ public partial class Border : View, IContentView, IBorderView, IPaddingElement
  {
  float[]? _strokeDashPattern;
 

src/Controls/src/Core/VisualElement/VisualElement.Mapper.cs

@@ -32,26 +32,21 @@ internal static new void RemapForControls()
  viewMapper.ReplaceMapping<IView, IViewHandler>(SemanticProperties.DescriptionProperty.PropertyName, MapSemanticPropertiesDescriptionProperty);
  viewMapper.ReplaceMapping<IView, IViewHandler>(SemanticProperties.HintProperty.PropertyName, MapSemanticPropertiesHintProperty);
  viewMapper.ReplaceMapping<IView, IViewHandler>(SemanticProperties.HeadingLevelProperty.PropertyName, MapSemanticPropertiesHeadingLevelProperty);
- viewMapper.ModifyMapping<IView, IViewHandler>(nameof(IView.Height), MapHeight);
- viewMapper.ModifyMapping<IView, IViewHandler>(nameof(IView.Width), MapWidth);
+ viewMapper.ModifyMapping<IView, IViewHandler>(nameof(IView.Height), MapWidthOrHeight);
+ viewMapper.ModifyMapping<IView, IViewHandler>(nameof(IView.Width), MapWidthOrHeight);
 
  viewMapper.AppendToMapping<VisualElement, IViewHandler>(nameof(IViewHandler.ContainerView), MapContainerView);
 
  commandMapper.ModifyMapping<VisualElement, IViewHandler>(nameof(IView.Focus), MapFocus);
  }
 
- static void MapWidth(IViewHandler handler, IView view, Action<IElementHandler, IElement> action)
+ internal static void MapWidthOrHeight(IViewHandler handler, IView view, Action<IElementHandler, IElement> action)
  {
- if (view is VisualElement ve && ve.Batched)
- return;
-
- action?.Invoke(handler, view);
- }
-
- static void MapHeight(IViewHandler handler, IView view, Action<IElementHandler, IElement> action)
- {
- if (view is VisualElement ve && ve.Batched)
+ // If batched is set to true this means that VisualElement.Frame is being set from the platform layout pass
+ if (view is VisualElement ve && ve.Batched && !ve.DontSuppressHeightWidthRequestChangesToHandlers)
+ {
  return;
+ }
 
  action?.Invoke(handler, view);
  }

src/Controls/src/Core/VisualElement/VisualElement.cs

@@ -1624,6 +1624,17 @@ static void OnIsFocusedPropertyChanged(BindableObject bindable, object oldvalue,
  element.ChangeVisualState();
  }
 
+ // If we're in the midst of updating the Frame property on VisualElement
+ // we suppress WidthProperty and HeightProperty from propagating to the handler
+ // Updates to the Frame is really just the platform informing
+ // the xplat code of it's actual dimensions, these aren't user controlled properties.
+ // But, if there's a scenario where a user modifies the WidthRequest or HeightRequest
+ // during the SizeAllocated events, then, we still want to propagate those changes to the handler
+ // in order to not break any previous scenarios where the user was relying on that behavior.
+ // We could also do this by wiring up mappers to the WidthRequestProperty and HeightRequestProperty but 
+ // that will somewhat change the order, so, this is least invasive.
+ bool DontSuppressHeightWidthRequestChangesToHandlers {get; set;}
+
  static void OnRequestChanged(BindableObject bindable, object oldvalue, object newvalue)
  {
  var constraint = LayoutConstraint.None;
@@ -1641,8 +1652,11 @@ static void OnRequestChanged(BindableObject bindable, object oldvalue, object ne
 
  if (element is IView fe)
  {
+ element.DontSuppressHeightWidthRequestChangesToHandlers = true;
  fe.Handler?.UpdateValue(nameof(IView.Width));
  fe.Handler?.UpdateValue(nameof(IView.Height));
+ element.DontSuppressHeightWidthRequestChangesToHandlers = false;
+
  fe.Handler?.UpdateValue(nameof(IView.MinimumHeight));
  fe.Handler?.UpdateValue(nameof(IView.MinimumWidth));
  fe.Handler?.UpdateValue(nameof(IView.MaximumHeight));

src/Controls/src/Xaml/Hosting/AppHostBuilderExtensions.cs

@@ -252,6 +252,7 @@ internal static MauiAppBuilder RemapForControls(this MauiAppBuilder builder)
  Shape.RemapForControls();
  WebView.RemapForControls();
  ContentPage.RemapForControls();
+ Border.RemapForControls();
 
  return builder;
  }

src/Controls/tests/Core.UnitTests/TestClasses/BasicVisualElement.cs

@@ -0,0 +1,23 @@
+using System.Threading.Tasks;
+using Microsoft.Maui.Animations;
+
+using Microsoft.Maui.Handlers;
+
+namespace Microsoft.Maui.Controls.Core.UnitTests
+{
+ public class BasicVisualElement : VisualElement
+ {
+ }
+
+ public class BasicVisualElementHandler : ViewHandler<BasicVisualElement, object>
+ {
+ public BasicVisualElementHandler(IPropertyMapper mapper, CommandMapper commandMapper = null) : base(mapper, commandMapper)
+ {
+ }
+
+ protected override object CreatePlatformView()
+ {
+ return new object();
+ }
+ }
+}

src/Controls/tests/Core.UnitTests/VisualElementTests.cs

@@ -2,7 +2,12 @@
 using System.Data.Common;
 using System.Threading.Tasks;
 using Microsoft.Maui.Controls.Shapes;
+
+using Microsoft.Maui.Controls.Hosting;
 using Microsoft.Maui.Graphics;
+using Microsoft.Maui.Hosting;
+using Microsoft.Maui.Platform;
+
 using Microsoft.Maui.Handlers;
 using Microsoft.Maui.Primitives;
 using Xunit;
@@ -237,5 +242,61 @@ public async Task ShadowDoesNotLeak()
 
  Assert.False(reference.IsAlive, "VisualElement should not be alive!");
  }
+
+ [Fact]
+ public void HandlerDoesntPropagateWidthChangesDuringBatchUpdates()
+ {
+ bool mapperCalled = false;
+
+ var mapper = new PropertyMapper<IView, ViewHandler>(ViewHandler.ViewMapper)
+ {
+ [nameof(IView.Height)] = (_,_) => mapperCalled = true,
+ [nameof(IView.Width)] = (_,_) => mapperCalled = true,
+ };
+
+ VisualElement.RemapForControls(mapper, new CommandMapper<IView, IViewHandler>(ViewHandler.ViewCommandMapper));
+
+ var mauiApp1 = MauiApp.CreateBuilder()
+ .UseMauiApp<ApplicationStub>()
+ .ConfigureMauiHandlers(handlers => handlers.AddHandler<BasicVisualElement>((services) => new BasicVisualElementHandler(mapper)))
+ .Build();
+
+ var element = new BasicVisualElement();
+ var platformView = element.ToPlatform(new MauiContext(mauiApp1.Services));
+
+ mapperCalled = false;
+ element.Frame = new Rect(0,0,100,100);
+ Assert.False(mapperCalled);
+ }
+
+ [Fact]
+ public void HandlerDoesPropagateWidthChangesWhenUpdatedDuringSizedChanged()
+ {
+ // read comments for DontSuppressHeightWidthRequestChangesToHandlers
+ // to understand why this test is here
+ bool mapperCalled = false;
+
+ var mapper = new PropertyMapper<IView, ViewHandler>(ViewHandler.ViewMapper)
+ {
+ [nameof(IView.Height)] = (_,_) => mapperCalled = true,
+ [nameof(IView.Width)] = (_,_) => mapperCalled = true,
+ };
+
+ VisualElement.RemapForControls(mapper, new CommandMapper<IView, IViewHandler>(ViewHandler.ViewCommandMapper));
+
+ var mauiApp1 = MauiApp.CreateBuilder()
+ .UseMauiApp<ApplicationStub>()
+ .ConfigureMauiHandlers(handlers => handlers.AddHandler<BasicVisualElement>((services) => new BasicVisualElementHandler(mapper)))
+ .Build();
+
+ var element = new BasicVisualElement();
+ var platformView = element.ToPlatform(new MauiContext(mauiApp1.Services));
+
+ element.SizeChanged += (_,_) => element.HeightRequest = 100;
+ mapperCalled = false;
+ element.Frame = new Rect(0,0,100,100);
+
+ Assert.True(mapperCalled);
+ }
  }
 }

src/Core/src/Handlers/Border/BorderHandler.Android.cs

@@ -45,14 +45,31 @@ public override void SetVirtualView(IView view)
  handler.PlatformView.AddView(view.ToPlatform(handler.MauiContext));
  }
 
- public static partial void MapHeight(IBorderHandler handler, IBorderView border)
+ /// <summary>
+ /// Maps the abstract <see cref="IView.Height"/> property to the platform-specific implementations.
+ /// </summary>
+ /// <param name="handler">The associated handler.</param>
+ /// <param name="border">The associated <see cref="IBorderView"/> instance.</param>
+ public static void MapHeight(IBorderHandler handler, IBorderView border)
  {
+ // These are no longer called from the Mapper the Mapper just uses
+ // MapHeightOrWidth
+ // TODO .NET9 obsolete this?
  handler.PlatformView?.UpdateHeight(border);
  handler.PlatformView?.InvalidateBorderStrokeBounds();
  }
 
- public static partial void MapWidth(IBorderHandler handler, IBorderView border)
+ /// <summary>
+ /// Maps the abstract <see cref="IView.Width"/> property to the platform-specific implementations.
+ /// </summary>
+ /// <param name="handler">The associated handler.</param>
+ /// <param name="border">The associated <see cref="IBorderView"/> instance.</param>
+ public static void MapWidth(IBorderHandler handler, IBorderView border)
  {
+
+ // These are no longer called from the Mapper the Mapper just uses
+ // MapHeightOrWidth
+ // TODO .NET9 obsolete these?
  handler.PlatformView?.UpdateWidth(border);
  handler.PlatformView?.InvalidateBorderStrokeBounds();
  }

src/Core/src/Handlers/Border/BorderHandler.cs

@@ -164,21 +164,5 @@ public static void MapContent(IBorderHandler handler, IBorderView border)
  }
 
  static partial void UpdateContent(IBorderHandler handler);
-
-#if __ANDROID__
- /// <summary>
- /// Maps the abstract <see cref="IView.Width"/> property to the platform-specific implementations.
- /// </summary>
- /// <param name="handler">The associated handler.</param>
- /// <param name="border">The associated <see cref="IBorderView"/> instance.</param>
- public static partial void MapWidth(IBorderHandler handler, IBorderView border);
-
- /// <summary>
- /// Maps the abstract <see cref="IView.Height"/> property to the platform-specific implementations.
- /// </summary>
- /// <param name="handler">The associated handler.</param>
- /// <param name="border">The associated <see cref="IBorderView"/> instance.</param>
- public static partial void MapHeight(IBorderHandler handler, IBorderView border);
-#endif
  }
 }