Compressed layout is back (maybe?)

src/Controls/src/Core/Layout/Layout.cs

@@ -13,7 +13,7 @@ namespace Microsoft.Maui.Controls
  /// Base class for layouts that allow you to arrange and group UI controls in your application.
  /// </summary>
  [ContentProperty(nameof(Children))]
- public abstract partial class Layout : View, Maui.ILayout, IList<IView>, IBindableLayout, IPaddingElement, IVisualTreeElement, ISafeAreaView, IInputTransparentContainerElement
+ public abstract partial class Layout : View, Maui.ILayout, IList<IView>, IBindableLayout, IPaddingElement, IVisualTreeElement, ISafeAreaView, IInputTransparentContainerElement, ICompressedLayout
  {
  protected ILayoutManager _layoutManager;
 
@@ -79,6 +79,8 @@ public IView this[int index]
  OnUpdate(index, value, old);
  }
  }
+
+ bool ICompressedLayout.IsHeadless => CompressedLayout.GetIsHeadless(this);
 
  /// <summary>Bindable property for <see cref="IsClippedToBounds"/>.</summary>
  public static readonly BindableProperty IsClippedToBoundsProperty =

src/Controls/src/Core/Platform/GestureManager/GestureManager.cs

@@ -76,7 +76,12 @@ void SetupGestureManager()
  if (GesturePlatformManager != null)
  return;
 
+#if PLATFORM
+ GesturePlatformManager = handler is IPlatformViewHandler ? new GesturePlatformManager(handler) : null;
+#else
  GesturePlatformManager = new GesturePlatformManager(handler);
+#endif
+
  _handler = handler;
  _containerView = handler.ContainerView;
  _platformView = handler.PlatformView;

src/Controls/tests/TestCases.HostApp/Issues/Issue24532.xaml

@@ -0,0 +1,33 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+ xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+ x:Class="Maui.Controls.Sample.Issues.Issue24532"
+ Title="Issue24532">
+
+ <Grid Padding="24" RowDefinitions="Auto,*" RowSpacing="8">
+ <Button x:Name="StartButton" Clicked="ButtonClicked" Text="Start" AutomationId="StartButton" />
+
+ <ScrollView Grid.Row="1">
+ <VerticalStackLayout x:Name="BindableContainer" BindableLayout.ItemsSource="{Binding Models}">
+ <BindableLayout.ItemTemplate>
+ <DataTemplate>
+ <Grid RowDefinitions="Auto,Auto,Auto" CompressedLayout.IsHeadless="True">
+ <Label Text="{Binding Header}" />
+ <Label Text="{Binding Content}" Grid.Row="1" />
+ <VerticalStackLayout Grid.Row="2" BindableLayout.ItemsSource="{Binding SubModels}" CompressedLayout.IsHeadless="True">
+ <BindableLayout.ItemTemplate>
+ <DataTemplate>
+ <VerticalStackLayout CompressedLayout.IsHeadless="True">
+ <Label Text="{Binding Header}" />
+ <Label Text="{Binding Content}" AutomationId="{Binding AutomationId}" />
+ </VerticalStackLayout>
+ </DataTemplate>
+ </BindableLayout.ItemTemplate>
+ </VerticalStackLayout>
+ </Grid>
+ </DataTemplate>
+ </BindableLayout.ItemTemplate>
+ </VerticalStackLayout>
+ </ScrollView>
+ </Grid>
+</ContentPage>

src/Controls/tests/TestCases.HostApp/Issues/Issue24532.xaml.cs

@@ -0,0 +1,144 @@
+using System;
+using System.Collections.ObjectModel;
+using System.Diagnostics;
+using Microsoft.Maui;
+using Microsoft.Maui.Controls;
+using Microsoft.Maui.Controls.Xaml;
+
+#if __IOS__ || MACCATALYST
+using PlatformView = UIKit.UIView;
+#elif __ANDROID__
+using PlatformView = Android.Views.View;
+#elif WINDOWS
+using PlatformView = Microsoft.UI.Xaml.FrameworkElement;
+#elif TIZEN
+using PlatformView = Tizen.NUI.BaseComponents.View;
+#elif (NETSTANDARD || !PLATFORM)
+using PlatformView = System.Object;
+#endif
+
+namespace Maui.Controls.Sample.Issues;
+
+[XamlCompilation(XamlCompilationOptions.Compile)]
+[Issue(IssueTracker.Github, 24532, "Rendering performance", PlatformAffected.All)]
+public partial class Issue24532 : ContentPage
+{
+ public List<Model> Models { get; set; }
+
+ public Issue24532()
+ {
+ Models = GenerateOneItem("Test0");
+ BindingContext = this;
+ InitializeComponent();
+ }
+
+ private async void ButtonClicked(object sender, EventArgs e)
+ {
+ var stopwatch = new Stopwatch();
+
+ var platformView = (PlatformView)BindableContainer.Handler!.PlatformView;
+
+ var capturedTimes = new List<long[]>();
+
+ var test1Models = GenerateItems("Test1", 70);
+ var test2Models = GenerateItems("Test2", 40);
+ var resetModel = GenerateOneItem("Test0");
+
+ for (var i = 0; i < 5; i++)
+ {
+ await Task.Delay(100);
+
+ Models = test1Models;
+ stopwatch.Restart();
+ OnPropertyChanged(nameof(Models));
+ await WaitForAutomationId(platformView, "Test1");
+ stopwatch.Stop();
+ var t1 = stopwatch.ElapsedMilliseconds;
+
+ await Task.Delay(100);
+
+ Models = test2Models;
+ stopwatch.Restart();
+ OnPropertyChanged(nameof(Models));
+ await WaitForAutomationId(platformView, "Test2");
+ stopwatch.Stop();
+ var t2 = stopwatch.ElapsedMilliseconds;
+
+ await Task.Delay(100);
+
+ stopwatch.Restart();
+ BindableContainer.Clear();
+ Models = resetModel;
+ OnPropertyChanged(nameof(Models));
+ await WaitForAutomationId(platformView, "Test0");
+ stopwatch.Stop();
+ var t3 = stopwatch.ElapsedMilliseconds;
+
+ capturedTimes.Add([t1, t2, t3]);
+ }
+
+ StartButton.Text =
+ $"{capturedTimes.Average(t => t[0])},{capturedTimes.Average(t => t[1])},{capturedTimes.Average(t => t[2])}";
+ }
+
+ async Task WaitForAutomationId(PlatformView platformView, string automationId)
+ {
+ var found = false;
+
+ while (!found)
+ {
+ await Task.Delay(20);
+#if IOS
+ int length;
+ while ((length = platformView.Subviews.Length) > 0) { platformView = platformView.Subviews[length - 1]; }
+ found = platformView.AccessibilityIdentifier == automationId;
+#elif ANDROID
+ int length;
+ while ((length = (platformView as Android.Views.ViewGroup)?.ChildCount ?? 0) > 0) { platformView = ((Android.Views.ViewGroup)platformView!).GetChildAt(length - 1); }
+ found = (platformView as Android.Widget.TextView)?.Text == automationId;
+#else
+ found = true;
+#endif
+ }
+ }
+
+ static List<Model> GenerateItems(string automationId, int count)
+ {
+ return
+ [
+ ..Enumerable.Range(0, count).Select(i => new Model { Content = $"Content {i}", Header = $"Header {i}" }),
+ ..GenerateOneItem(automationId)
+ ];
+ }
+
+ static List<Model> GenerateOneItem(string automationId)
+ {
+ return
+ [
+ new Model
+ {
+ Content = automationId,
+ Header = automationId,
+ SubModels =
+ [
+ new SubModel { Content = automationId, Header = automationId, AutomationId = automationId }
+ ]
+ }
+ ];
+ }
+
+ public class Model : SubModel
+ {
+ public SubModel[] SubModels { get; set; } = Enumerable.Range(0, 10).Select(i => new SubModel
+ {
+ Content = $"SubContent {i}", Header = $"SubHeader {i}"
+ }).ToArray();
+ }
+
+ public class SubModel
+ {
+ public string Header { get; set; }
+ public string Content { get; set; }
+ public string AutomationId { get; set; }
+ }
+}

src/Controls/tests/TestCases.HostApp/Issues/Issue99999.xaml

@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+ xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+ x:Class="Maui.Controls.Sample.Issues.Issue99999"
+ Title="Issue99999">
+
+ <Grid Padding="24" RowDefinitions="Auto,Auto" ColumnDefinitions="*,*,*,*,*" RowSpacing="16" ColumnSpacing="8">
+ <Entry x:Name="IndexEntry" Keyboard="Numeric" Placeholder="Index" />
+ <Button Text="Ins out" Clicked="OnInsOut" Grid.Row="0" Grid.Column="1" />
+ <Button Text="Rm out" Clicked="OnRmOut" Grid.Row="0" Grid.Column="2" />
+ <Button Text="Ins in" Clicked="OnInsIn" Grid.Row="0" Grid.Column="3" />
+ <Button Text="Rm in" Clicked="OnRmIn" Grid.Row="0" Grid.Column="4" />
+
+ <VerticalStackLayout x:Name="OuterLayout" Spacing="16" Grid.Row="1" Grid.ColumnSpan="5">
+ <Label Text="Text0" BackgroundColor="LightBlue" HeightRequest="20" />
+ <Label Text="Text1" BackgroundColor="LightBlue" HeightRequest="20" />
+ <VerticalStackLayout x:Name="InnerLayout" Padding="12" Spacing="8" CompressedLayout.IsHeadless="True">
+ <Label Text="Text2" BackgroundColor="LightGreen" HeightRequest="20" />
+ <Label Text="Text3" BackgroundColor="LightGreen" HeightRequest="20" />
+ <Label Text="Text4" BackgroundColor="LightGreen" HeightRequest="20" />
+ </VerticalStackLayout>
+ <Label Text="Text5" BackgroundColor="LightBlue" HeightRequest="20" />
+ <Label Text="Text6" BackgroundColor="LightBlue" HeightRequest="20" />
+ </VerticalStackLayout>
+ </Grid>
+</ContentPage>

src/Controls/tests/TestCases.HostApp/Issues/Issue99999.xaml.cs

@@ -0,0 +1,43 @@
+using System;
+using Microsoft.Maui;
+using Microsoft.Maui.Controls;
+using Microsoft.Maui.Controls.Xaml;
+
+namespace Maui.Controls.Sample.Issues;
+
+[XamlCompilation(XamlCompilationOptions.Compile)]
+[Issue(IssueTracker.Github, 99999, "CompressedLayout is not working", PlatformAffected.All)]
+
+public partial class Issue99999 : ContentPage
+{
+ int _count = 6;
+
+ public Issue99999()
+ {
+ InitializeComponent();
+ }
+
+ private void OnInsOut(object sender, EventArgs e)
+ {
+ var index = int.Parse(IndexEntry.Text);
+ OuterLayout.Insert(index, new Label { Text = $"Text{++_count}" });
+ }
+
+ private void OnRmOut(object sender, EventArgs e)
+ {
+ var index = int.Parse(IndexEntry.Text);
+ OuterLayout.RemoveAt(index);
+ }
+
+ private void OnInsIn(object sender, EventArgs e)
+ {
+ var index = int.Parse(IndexEntry.Text);
+ InnerLayout.Insert(index, new Label { Text = $"Text{++_count}" });
+ }
+
+ private void OnRmIn(object sender, EventArgs e)
+ {
+ var index = int.Parse(IndexEntry.Text);
+ InnerLayout.RemoveAt(index);
+ }
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue24532.cs

@@ -0,0 +1,41 @@
+#if ANDROID || IOS || MACCATALYST
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues
+{
+ public class Issue24532 : _IssuesUITest
+ {
+ public Issue24532(TestDevice device) : base(device) { }
+
+ public override string Issue => "Rendering performance";
+
+ [Test]
+ [Category(UITestCategories.Performance)]
+ public async Task RenderingPerformance()
+ {
+ var button = App.WaitForElement("StartButton");
+ App.Tap("StartButton");
+
+ string? text;
+ while (true)
+ {
+ text = button.GetText();
+ if (string.IsNullOrEmpty(text) || text == "Start")
+ {
+ await Task.Delay(1000);
+ continue;
+ }
+
+ break;
+ }
+
+ var times = text.Split(',');
+ Console.WriteLine(@$"First render: {times[0]}ms");
+ Console.WriteLine(@$"Binding context changed: {times[1]}ms");
+ Console.WriteLine(@$"Clear: {times[2]}ms");
+ }
+ }
+}
+#endif

src/Core/src/Core/ICompressedLayout.cs

@@ -0,0 +1,17 @@
+namespace Microsoft.Maui
+{
+
+ /// <summary>
+ /// Provides information about whether the ILayout is compressed.
+ /// </summary>
+ /// <remarks>
+ /// A compressed layout is not included in the platform tree.
+ /// </remarks>
+ internal interface ICompressedLayout
+ {
+ /// <summary>
+ /// Specifies whether the ILayout is compressed.
+ /// </summary>
+ bool IsHeadless { get; }
+ }
+}