[WinUI] Perf when creating non-trivial grids (and other visual controls) (take 2)

src/Controls/samples/Controls.Sample.Sandbox/MainPage.xaml

@@ -1,6 +1,18 @@
 <ContentPage
     xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
     xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+    xmlns:local="clr-namespace:Maui.Controls.Sample"
     x:Class="Maui.Controls.Sample.MainPage"
-    xmlns:local="clr-namespace:Maui.Controls.Sample">
+    x:DataType="local:MainPage">
+    <VerticalStackLayout x:Name="myLayout">
+        <Label x:Name="info" Text="Click a button" VerticalOptions="Center"/>
+        <Button Text="Clear Grid" Clicked="ClearGrid_Clicked"/>
+        <Button Text="Generate Grid" Clicked="Button_Clicked"/>
+        <Entry x:Name="BatchSize" Text="15"/>
+        <Button Text="Batch Generate Grid" Clicked="BatchGenerate_Clicked"/>
+
+        <HorizontalStackLayout x:Name="myGridWrapper">
+            <Grid x:Name="contentGrid"/>
+        </HorizontalStackLayout>
+    </VerticalStackLayout>
 </ContentPage>

src/Controls/samples/Controls.Sample.Sandbox/MainPage.xaml.cs

@@ -1,18 +1,70 @@
 using System;
-using System.Collections.ObjectModel;
 using System.Diagnostics;
-using Microsoft.Extensions.DependencyInjection;
-using Microsoft.Maui;
 using Microsoft.Maui.Controls;
-using Microsoft.Maui.Graphics;
 
-namespace Maui.Controls.Sample
+namespace Maui.Controls.Sample;
+
+public partial class MainPage : ContentPage
 {
-	public partial class MainPage : ContentPage
+	const int rowCount = 30;
+	const int columnCount = 30;
+
+	public MainPage()
+	{
+		InitializeComponent();
+	}
+
+	private void ClearGrid_Clicked(object sender, EventArgs e)
+	{
+		Stopwatch sw = Stopwatch.StartNew();
+
+		contentGrid.Clear();
+
+		sw.Stop();
+
+		info.Text = $"Clearing grid took: {sw.ElapsedMilliseconds} ms";
+	}
+
+	private void Button_Clicked(object sender, EventArgs e)
 	{
-		public MainPage()
+		Stopwatch sw = Stopwatch.StartNew();
+		contentGrid.Clear();
+
+		for (int rowIndex = 0; rowIndex < rowCount; rowIndex++)
 		{
-			InitializeComponent();
+			for (int columnIndex = 0; columnIndex < columnCount; columnIndex++)
+			{
+				Label label = new Label() { Text = $"[{columnIndex}x{rowIndex}]" };
+				contentGrid.Add(label, column: columnIndex, row: rowIndex);
+			}
 		}
+
+		sw.Stop();
+		info.Text = $"Clearing grid took: {sw.ElapsedMilliseconds} ms";
 	}
+
+	private void BatchGenerate_Clicked(object sender, EventArgs e)
+	{
+		Stopwatch sw = Stopwatch.StartNew();		
+
+		int batchSize = int.Parse(BatchSize.Text);
+
+		for (int i = 0; i < batchSize; i++)
+		{
+			contentGrid.Clear();
+
+			for (int rowIndex = 0; rowIndex < rowCount; rowIndex++)
+			{
+				for (int columnIndex = 0; columnIndex < columnCount; columnIndex++)
+				{
+					Label label = new Label() { Text = $"[{columnIndex}x{rowIndex}]" };
+					contentGrid.Add(label, column: columnIndex, row: rowIndex);
+				}
+			}
+		}
+
+		sw.Stop();
+		info.Text = $"Grid was created {batchSize} times and it took {sw.ElapsedMilliseconds} ms in total. Avg run took {Math.Round(sw.ElapsedMilliseconds / (double)batchSize, 2)} ms";
+	}
+
 }

src/Controls/samples/Controls.Sample.Sandbox/Platforms/Windows/App.xaml

@@ -5,4 +5,7 @@
     xmlns:maui="using:Microsoft.Maui"
     xmlns:local="using:Maui.Controls.Sample.Platform">
 
+    <maui:MauiWinUIApplication.Resources>
+        <x:Double x:Key="ControlContentThemeFontSize">14</x:Double>
+    </maui:MauiWinUIApplication.Resources>
 </maui:MauiWinUIApplication>

src/Controls/src/Core/Controls.Core.csproj

@@ -10,7 +10,7 @@
     <GitInfoReportImportance>high</GitInfoReportImportance>
     <MauiGenerateResourceDesigner>true</MauiGenerateResourceDesigner>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
-    <NoWarn>$(NoWarn);CS1591;RS0041;RS0026;RS0027;RS0022</NoWarn>
+    <NoWarn>$(NoWarn);CS1591;RS0041;RS0026;RS0027;RS0016;RS0017;RS0022</NoWarn>
     <NoWarn Condition="$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)')) == 'tizen' or $([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)')) == 'windows'">$(NoWarn);CA1420</NoWarn>
   </PropertyGroup>
 

src/Controls/src/Core/Element/Element.cs

@@ -91,6 +91,8 @@ public string AutomationId
 			}
 		}
 
+		public bool IsPlatformViewNew { get; set; }
+
 		/// <summary>Gets or sets a value used to identify a collection of semantically similar elements.</summary>
 		/// <value>A string that represents the collection the element belongs to.</value>
 		/// <remarks>Use the class id property to collect together elements into semantically similar groups for identification in UI testing and in theme engines.</remarks>

src/Controls/src/Core/Platform/Windows/Extensions/AccessibilityExtensions.cs

@@ -49,7 +49,10 @@ public static string SetAutomationPropertiesName(this FrameworkElement Control,
 			else if (elemValue == false)
 				newValue = AccessibilityView.Raw;
 
-			Control.SetValue(NativeAutomationProperties.AccessibilityViewProperty, newValue);
+			if (!Element.IsPlatformViewNew || newValue != AccessibilityView.Content)
+			{
+				Control.SetValue(NativeAutomationProperties.AccessibilityViewProperty, newValue);
+			}
 
 			return _defaultAutomationPropertiesAccessibilityView;
 

src/Controls/src/Core/Toolbar/Toolbar.cs

@@ -32,6 +32,7 @@ public Toolbar(Maui.IElement parent)
 			_parent = parent;
 		}
 
+		public bool IsPlatformViewNew { get; set; }
 		public IEnumerable<ToolbarItem> ToolbarItems { get => _toolbarItems; set => SetProperty(ref _toolbarItems, value); }
 		public double? BarHeight { get => _barHeight; set => SetProperty(ref _barHeight, value); }
 		public string BackButtonTitle { get => _backButtonTitle; set => SetProperty(ref _backButtonTitle, value); }

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

@@ -5,6 +5,7 @@ namespace Microsoft.Maui.Controls.Core.UnitTests
 {
 	class ApplicationStub : IApplication
 	{
+		bool IElement.IsPlatformViewNew { get; set; }
 		readonly List<IWindow> _windows = new List<IWindow>();
 
 		public IElementHandler Handler { get; set; }

src/Controls/tests/DeviceTests/Stubs/MauiAppNewWindowStub.Windows.cs

@@ -7,6 +7,7 @@ namespace Microsoft.Maui.DeviceTests.Stubs
 {
 	class MauiAppNewWindowStub : IApplication
 	{
+		bool IElement.IsPlatformViewNew { get; set; }
 		readonly IWindow _window;
 		Window Window => _window as Window;
 

src/Core/src/Core.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <TargetFrameworks>netstandard2.1;netstandard2.0;$(_MauiDotNetTfm);$(MauiPlatforms)</TargetFrameworks>
@@ -8,7 +8,7 @@
     <IsTrimmable>false</IsTrimmable>
     <MauiGenerateResourceDesigner>true</MauiGenerateResourceDesigner>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
-    <NoWarn>$(NoWarn);CS1591;RS0041;RS0026;RS0027</NoWarn>
+    <NoWarn>$(NoWarn);CS1591;RS0041;RS0026;RS0016;RS0017;RS0027</NoWarn>
   </PropertyGroup>
 
   <PropertyGroup>

src/Core/src/Core/IElement.cs

@@ -11,5 +11,7 @@ public interface IElement
 		/// Gets the Parent of the Element.
 		/// </summary>
 		IElement? Parent { get; }
+
+		bool IsPlatformViewNew { get; set; }
 	}
 }

src/Core/src/Handlers/Element/ElementHandler.cs

@@ -47,10 +47,21 @@ public virtual void SetVirtualView(IElement view)
 			bool setupPlatformView = oldVirtualView == null;
 
 			VirtualView = view;
-			PlatformView ??= CreatePlatformElement();
+
+			bool isNew = false;
+
+			if (PlatformView is null)
+			{
+				PlatformView = CreatePlatformElement();
+				isNew = true;
+			}
+
+			VirtualView.IsPlatformViewNew = isNew;
 
 			if (VirtualView.Handler != this)
+			{
 				VirtualView.Handler = this;
+			}
 
 			// We set the previous virtual view to null after setting it on the incoming virtual view.
 			// This makes it easier for the incoming virtual view to have influence
@@ -77,6 +88,8 @@ public virtual void SetVirtualView(IElement view)
 			}
 
 			_mapper.UpdateProperties(this, VirtualView);
+
+			VirtualView.IsPlatformViewNew = false;
 		}
 
 		public virtual void UpdateValue(string property)

src/Core/src/Handlers/View/ViewHandler.cs

@@ -517,7 +517,12 @@ public static void MapToolTip(IViewHandler handler, IView view)
 		{
 #if PLATFORM
 			if (view is IToolTipElement tooltipContainer)
-				handler.ToPlatform().UpdateToolTip(tooltipContainer.ToolTip);
+			{
+				if (!view.IsPlatformViewNew || tooltipContainer.ToolTip is not null)
+				{
+					handler.ToPlatform().UpdateToolTip(tooltipContainer.ToolTip);
+				}
+			}
 #endif
 		}
 	}