Move ILayoutRoot to PresentationSource

# Conflicts:
#	tests/Avalonia.Controls.UnitTests/TabControlTests.cs

src/Avalonia.Base/Layout/ILayoutManager.cs

@@ -6,7 +6,7 @@ namespace Avalonia.Layout
     /// <summary>
     /// Manages measuring and arranging of controls.
     /// </summary>
-    internal interface ILayoutManager : IDisposable
+    public interface ILayoutManager : IDisposable
     {
         /// <summary>
         /// Raised when the layout manager completes a layout pass.

src/Avalonia.Base/Layout/ILayoutRoot.cs

@@ -10,11 +10,13 @@ namespace Avalonia.Layout
         /// <summary>
         /// The scaling factor to use in layout.
         /// </summary>
-        double LayoutScaling { get; }
+        public double LayoutScaling { get; }
 
         /// <summary>
         /// Associated instance of layout manager
         /// </summary>
-        internal ILayoutManager LayoutManager { get; }
+        public ILayoutManager LayoutManager { get; }
+        
+        public Layoutable RootVisual { get; }
     }
 }

src/Avalonia.Base/Layout/LayoutHelper.cs

@@ -140,8 +140,7 @@ namespace Avalonia.Layout
         /// </summary>
         /// <param name="control">The control.</param>
         /// <exception cref="Exception">Thrown when control has no root or returned layout scaling is invalid.</exception>
-        public static double GetLayoutScale(Layoutable control)
-            => control.VisualRoot is ILayoutRoot layoutRoot ? layoutRoot.LayoutScaling : 1.0;
+        public static double GetLayoutScale(Layoutable control) => control.GetLayoutRoot()?.LayoutScaling ?? 1.0;
 
         /// <summary>
         /// Rounds a size to integer values for layout purposes, compensating for high DPI screen

src/Avalonia.Base/Layout/LayoutManager.cs

@@ -9,6 +9,7 @@ using Avalonia.Metadata;
 using Avalonia.Rendering;
 using Avalonia.Threading;
 using Avalonia.Utilities;
+using Avalonia.VisualTree;
 
 #nullable enable
 
@@ -20,7 +21,7 @@ namespace Avalonia.Layout
     internal class LayoutManager : ILayoutManager, IDisposable
     {
         private const int MaxPasses = 10;
-        private readonly Layoutable _owner;
+        private readonly ILayoutRoot _owner;
         private readonly LayoutQueue<Layoutable> _toMeasure = new LayoutQueue<Layoutable>(v => !v.IsMeasureValid);
         private readonly LayoutQueue<Layoutable> _toArrange = new LayoutQueue<Layoutable>(v => !v.IsArrangeValid);
         private readonly List<Layoutable> _toArrangeAfterMeasure = new();
@@ -33,7 +34,7 @@ namespace Avalonia.Layout
 
         public LayoutManager(ILayoutRoot owner)
         {
-            _owner = owner as Layoutable ?? throw new ArgumentNullException(nameof(owner));
+            _owner = owner;
             _invokeOnRender = ExecuteQueuedLayoutPass;
         }
 
@@ -62,7 +63,7 @@ namespace Avalonia.Layout
 #endif
             }
 
-            if (control.VisualRoot != _owner)
+            if (control.GetLayoutRoot() != _owner)
             {
                 throw new ArgumentException("Attempt to call InvalidateMeasure on wrong LayoutManager.");
             }
@@ -92,7 +93,7 @@ namespace Avalonia.Layout
 #endif
             }
 
-            if (control.VisualRoot != _owner)
+            if (control.GetLayoutRoot() != _owner)
             {
                 throw new ArgumentException("Attempt to call InvalidateArrange on wrong LayoutManager.");
             }
@@ -187,9 +188,12 @@ namespace Avalonia.Layout
 
             try
             {
+                if (_owner?.RootVisual == null)
+                    return;
+                var root = _owner.RootVisual;
                 _running = true;
-                Measure(_owner);
-                Arrange(_owner);
+                Measure(root);
+                Arrange(root);
             }
             finally
             {
@@ -299,7 +303,7 @@ namespace Avalonia.Layout
             // control to be removed.
             if (!control.IsMeasureValid)
             {
-                if (control is ILayoutRoot root)
+                if (control.GetLayoutRoot()?.RootVisual == control)
                 {
                     control.Measure(Size.Infinity);
                 }
@@ -328,7 +332,7 @@ namespace Avalonia.Layout
 
             if (!control.IsArrangeValid)
             {
-                if (control is ILayoutRoot root)
+                if (control.GetLayoutRoot()?.RootVisual == control)
                     control.Arrange(new Rect(control.DesiredSize));
                 else if (control.PreviousArrange != null)
                 {

src/Avalonia.Base/Layout/Layoutable.cs

@@ -168,7 +168,7 @@ namespace Avalonia.Layout
         {
             add
             {
-                if (_effectiveViewportChanged is null && VisualRoot is ILayoutRoot r && !_isAttachingToVisualTree)
+                if (_effectiveViewportChanged is null && this.GetLayoutRoot() is {} r && !_isAttachingToVisualTree)
                 {
                     r.LayoutManager.RegisterEffectiveViewportListener(this);
                 }
@@ -180,7 +180,7 @@ namespace Avalonia.Layout
             {
                 _effectiveViewportChanged -= value;
 
-                if (_effectiveViewportChanged is null && VisualRoot is ILayoutRoot r)
+                if (_effectiveViewportChanged is null && this.GetLayoutRoot() is {} r)
                 {
                     r.LayoutManager.UnregisterEffectiveViewportListener(this);
                 }
@@ -194,7 +194,7 @@ namespace Avalonia.Layout
         {
             add
             {
-                if (_layoutUpdated is null && VisualRoot is ILayoutRoot r && !_isAttachingToVisualTree)
+                if (_layoutUpdated is null && this.GetLayoutRoot() is {} r && !_isAttachingToVisualTree)
                 {
                     r.LayoutManager.LayoutUpdated += LayoutManagedLayoutUpdated;
                 }
@@ -206,7 +206,7 @@ namespace Avalonia.Layout
             {
                 _layoutUpdated -= value;
 
-                if (_layoutUpdated is null && VisualRoot is ILayoutRoot r)
+                if (_layoutUpdated is null && this.GetLayoutRoot() is {} r)
                 {
                     r.LayoutManager.LayoutUpdated -= LayoutManagedLayoutUpdated;
                 }
@@ -221,7 +221,7 @@ namespace Avalonia.Layout
         /// schedule layout passes itself.
         /// </remarks>
         
-        public void UpdateLayout() => (this.GetPresentationSource()?.RootVisual as ILayoutRoot)?.LayoutManager?.ExecuteLayoutPass();
+        public void UpdateLayout() => this.GetLayoutManager()?.ExecuteLayoutPass();
 
         /// <summary>
         /// Gets or sets the width of the element.
@@ -449,7 +449,7 @@ namespace Avalonia.Layout
 
                 if (IsAttachedToVisualTree)
                 {
-                    (VisualRoot as ILayoutRoot)?.LayoutManager.InvalidateMeasure(this);
+                    this.GetLayoutManager()?.InvalidateMeasure(this);
                     InvalidateVisual();
                 }
                 OnMeasureInvalidated();
@@ -466,7 +466,7 @@ namespace Avalonia.Layout
                 Logger.TryGet(LogEventLevel.Verbose, LogArea.Layout)?.Log(this, "Invalidated arrange");
 
                 IsArrangeValid = false;
-                (VisualRoot as ILayoutRoot)?.LayoutManager?.InvalidateArrange(this);
+                this.GetLayoutManager()?.InvalidateArrange(this);
                 InvalidateVisual();
             }
         }
@@ -794,7 +794,7 @@ namespace Avalonia.Layout
                 _isAttachingToVisualTree = false;
             }
 
-            if (e.Root is ILayoutRoot r)
+            if (this.GetLayoutRoot() is {} r)
             {
                 if (_layoutUpdated is object)
                 {
@@ -810,7 +810,7 @@ namespace Avalonia.Layout
 
         protected override void OnDetachedFromVisualTreeCore(VisualTreeAttachmentEventArgs e)
         {
-            if (e.Root is ILayoutRoot r)
+            if (this.GetLayoutRoot() is {} r)
             {
                 if (_layoutUpdated is object)
                 {
@@ -853,7 +853,7 @@ namespace Avalonia.Layout
                     // they will need to be registered with the layout manager now that they
                     // are again effectively visible. If IsEffectivelyVisible becomes an observable
                     // property then we can piggy-pack on that; for the moment we do this manually.
-                    if (VisualRoot is ILayoutRoot layoutRoot)
+                    if (this.GetLayoutRoot() is {} layoutRoot)
                     {
                         var count = VisualChildren.Count;
 

src/Avalonia.Base/Rendering/IPresentationSource.cs

@@ -1,5 +1,6 @@
 using System;
 using Avalonia.Input;
+using Avalonia.Layout;
 using Avalonia.Platform;
 
 namespace Avalonia.Rendering;
@@ -13,6 +14,8 @@ public interface IPresentationSource
     internal IHitTester HitTester { get; }
     
     internal IInputRoot InputRoot { get; }
+
+    internal ILayoutRoot LayoutRoot { get; }
     
     public Visual? RootVisual { get; }
     

src/Avalonia.Base/VisualTree/VisualExtensions.cs

@@ -3,6 +3,7 @@ using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Runtime.CompilerServices;
+using Avalonia.Layout;
 using Avalonia.Platform;
 using Avalonia.Rendering;
 using Avalonia.Utilities;
@@ -464,6 +465,14 @@ namespace Avalonia.VisualTree
         // TODO: Verify all usages, this is no longer necessary a TopLevel
         internal static Visual? GetVisualRoot(this Visual visual) => visual.PresentationSource?.RootVisual;
 
+        internal static ILayoutRoot? GetLayoutRoot(this Visual visual) => visual.PresentationSource?.LayoutRoot;
+
+        /// <summary>
+        /// Gets the layout manager for the visual's presentation source, or null if the visual is not attached to a visual root.
+        /// </summary>
+        public static ILayoutManager? GetLayoutManager(this Visual visual) =>
+            visual.PresentationSource?.LayoutRoot.LayoutManager;
+
         /// <summary>
         /// Attempts to obtain platform settings from the visual's root.
         /// This will return null if the visual is not attached to a visual root.

src/Avalonia.Controls/DateTimePickers/DatePicker.cs

@@ -8,6 +8,7 @@ using Avalonia.Layout;
 using System;
 using System.Collections.Generic;
 using System.Globalization;
+using Avalonia.VisualTree;
 
 namespace Avalonia.Controls
 {
@@ -406,7 +407,7 @@ namespace Avalonia.Controls
             // Overlay popup hosts won't get measured until the next layout pass, but we need the
             // template to be applied to `_presenter` now. Detect this case and force a layout pass.
             if (!_presenter.IsMeasureValid)
-                (VisualRoot as ILayoutRoot)?.LayoutManager?.ExecuteInitialLayoutPass();
+                this.GetLayoutManager()?.ExecuteInitialLayoutPass();
 
             var deltaY = _presenter.GetOffsetForPopup();
 

src/Avalonia.Controls/DateTimePickers/TimePicker.cs

@@ -7,6 +7,7 @@ using System;
 using System.Globalization;
 using Avalonia.Controls.Utils;
 using Avalonia.Automation.Peers;
+using Avalonia.VisualTree;
 
 namespace Avalonia.Controls
 {
@@ -380,7 +381,7 @@ namespace Avalonia.Controls
             // Overlay popup hosts won't get measured until the next layout pass, but we need the
             // template to be applied to `_presenter` now. Detect this case and force a layout pass.
             if (!_presenter.IsMeasureValid)
-                (VisualRoot as ILayoutRoot)?.LayoutManager?.ExecuteInitialLayoutPass();
+                this.GetLayoutManager()?.ExecuteInitialLayoutPass();
 
             var deltaY = _presenter.GetOffsetForPopup();
 

src/Avalonia.Controls/Grid.cs

@@ -2117,7 +2117,7 @@ namespace Avalonia.Controls
             {
                 // DpiScale dpiScale = GetDpi();
                 // double dpi = columns ? dpiScale.DpiScaleX : dpiScale.DpiScaleY;
-                var dpi = (VisualRoot as ILayoutRoot)?.LayoutScaling ?? 1.0;
+                var dpi = this.GetLayoutRoot()?.LayoutScaling ?? 1.0;
                 double[] roundingErrors = RoundingErrors;
                 double roundedTakenSize = 0;
 

src/Avalonia.Controls/GridSplitter.cs

@@ -13,6 +13,7 @@ using Avalonia.Interactivity;
 using Avalonia.Layout;
 using Avalonia.Media;
 using Avalonia.Utilities;
+using Avalonia.VisualTree;
 
 namespace Avalonia.Controls
 {
@@ -226,7 +227,7 @@ namespace Avalonia.Controls
                     ResizeDirection = resizeDirection,
                     SplitterLength = Math.Min(Bounds.Width, Bounds.Height),
                     ResizeBehavior = GetEffectiveResizeBehavior(resizeDirection),
-                    Scaling = (VisualRoot as ILayoutRoot)?.LayoutScaling ?? 1,
+                    Scaling = this.GetLayoutRoot()?.LayoutScaling ?? 1,
                 };
 
                 // Store the rows and columns to resize on drag events.

src/Avalonia.Controls/PresentationSource/PresentationSource.Layout.cs

@@ -0,0 +1,69 @@
+using System;
+using System.ComponentModel;
+using Avalonia.Layout;
+using Avalonia.Rendering;
+
+namespace Avalonia.Controls;
+
+internal partial class PresentationSource : ILayoutRoot
+{
+    private LayoutDiagnosticBridge? _layoutDiagnosticBridge;
+    public double LayoutScaling => RenderScaling;
+    public ILayoutManager LayoutManager { get; }
+    ILayoutRoot IPresentationSource.LayoutRoot => this;
+    Layoutable ILayoutRoot.RootVisual => RootVisual;
+
+    private ILayoutManager CreateLayoutManager()
+    {
+        var manager = new LayoutManager(this);
+        _layoutDiagnosticBridge = new LayoutDiagnosticBridge(Renderer.Diagnostics, manager);
+        _layoutDiagnosticBridge.SetupBridge();
+        return manager;
+    }
+
+
+    /// <summary>
+    /// Provides layout pass timing from the layout manager to the renderer, for diagnostics purposes.
+    /// </summary>
+    private sealed class LayoutDiagnosticBridge : IDisposable
+    {
+        private readonly RendererDiagnostics _diagnostics;
+        private readonly LayoutManager _layoutManager;
+        private bool _isHandling;
+
+        public LayoutDiagnosticBridge(RendererDiagnostics diagnostics, LayoutManager layoutManager)
+        {
+            _diagnostics = diagnostics;
+            _layoutManager = layoutManager;
+
+            diagnostics.PropertyChanged += OnDiagnosticsPropertyChanged;
+        }
+
+        public void SetupBridge()
+        {
+            var needsHandling = (_diagnostics.DebugOverlays & RendererDebugOverlays.LayoutTimeGraph) != 0;
+            if (needsHandling != _isHandling)
+            {
+                _isHandling = needsHandling;
+                _layoutManager.LayoutPassTimed = needsHandling
+                    ? timing => _diagnostics.LastLayoutPassTiming = timing
+                    : null;
+            }
+        }
+
+        private void OnDiagnosticsPropertyChanged(object? sender, PropertyChangedEventArgs e)
+        {
+            if (e.PropertyName == nameof(RendererDiagnostics.DebugOverlays))
+            {
+                SetupBridge();
+            }
+        }
+
+        public void Dispose()
+        {
+            _diagnostics.PropertyChanged -= OnDiagnosticsPropertyChanged;
+            _layoutManager.LayoutPassTimed = null;
+        }
+    }
+    
+}

src/Avalonia.Controls/PresentationSource/PresentationSource.cs

@@ -1,6 +1,7 @@
 using System;
 using Avalonia.Input;
 using Avalonia.Input.TextInput;
+using Avalonia.Layout;
 using Avalonia.Logging;
 using Avalonia.Platform;
 using Avalonia.Rendering;
@@ -37,8 +38,9 @@ internal partial class PresentationSource : IPresentationSource, IInputRoot, IDi
         
         Renderer = new CompositingRenderer(this, PlatformImpl.Compositor, () => PlatformImpl.Surfaces ?? []);
         Renderer.SceneInvalidated += SceneInvalidated;
-        RootVisual = rootVisual;
+        LayoutManager = CreateLayoutManager();
         
+        RootVisual = rootVisual;
     }
 
     // In WPF it's a Visual and it's nullable. For now we have it as non-nullable InputElement since 
@@ -81,6 +83,9 @@ internal partial class PresentationSource : IPresentationSource, IInputRoot, IDi
 
     public void Dispose()
     {
+        _layoutDiagnosticBridge?.Dispose();
+        _layoutDiagnosticBridge = null;
+        LayoutManager.Dispose();
         Renderer.SceneInvalidated -= SceneInvalidated;
         // We need to wait for the renderer to complete any in-flight operations
         Renderer.Dispose();

src/Avalonia.Controls/TopLevel.cs

@@ -39,7 +39,6 @@ namespace Avalonia.Controls
     /// </remarks>
     [TemplatePart("PART_TransparencyFallback", typeof(Border))]
     public abstract class TopLevel : ContentControl,
-        ILayoutRoot,
         ICloseable,
         IStyleHost,
         ILogicalRoot
@@ -126,12 +125,10 @@ namespace Avalonia.Controls
         private Size _clientSize;
         private Size? _frameSize;
         private WindowTransparencyLevel _actualTransparencyLevel;
-        private ILayoutManager? _layoutManager;
         private Border? _transparencyFallbackBorder;
         private TargetWeakEventSubscriber<TopLevel, ResourcesChangedEventArgs>? _resourcesChangesSubscriber;
         private IStorageProvider? _storageProvider;
         private Screens? _screens;
-        private LayoutDiagnosticBridge? _layoutDiagnosticBridge;
         private PresentationSource _source;
         internal PresentationSource PresentationSource => _source;
         internal IInputRoot InputRoot => _source;
@@ -384,26 +381,7 @@ namespace Avalonia.Controls
             remove => RemoveHandler(BackRequestedEvent, value);
         }
 
-        internal ILayoutManager LayoutManager
-        {
-            get
-            {
-                if (_layoutManager is null)
-                {
-                    _layoutManager = CreateLayoutManager();
-
-                    if (_layoutManager is LayoutManager typedLayoutManager)
-                    {
-                        _layoutDiagnosticBridge = new LayoutDiagnosticBridge(Renderer.Diagnostics, typedLayoutManager);
-                        _layoutDiagnosticBridge.SetupBridge();
-                    }
-                }
-
-                return _layoutManager;
-            }
-        }
-
-        ILayoutManager ILayoutRoot.LayoutManager => LayoutManager;
+        internal ILayoutManager LayoutManager => _source.LayoutManager;
 
         /// <summary>
         /// Gets the platform-specific window implementation.
@@ -504,8 +482,6 @@ namespace Avalonia.Controls
             return control.GetValue(AutoSafeAreaPaddingProperty);
         }
 
-        double ILayoutRoot.LayoutScaling => _scaling;
-
         /// <inheritdoc/>
         public double RenderScaling => _scaling;
 
@@ -641,11 +617,6 @@ namespace Avalonia.Controls
             }
         }
 
-        /// <summary>
-        /// Creates the layout manager for this <see cref="TopLevel" />.
-        /// </summary>
-        private protected virtual ILayoutManager CreateLayoutManager() => new LayoutManager(this);
-
         /// <summary>
         /// Handles a paint notification from <see cref="ITopLevelImpl.Resized"/>.
         /// </summary>
@@ -682,9 +653,6 @@ namespace Avalonia.Controls
                 _applicationThemeHost.ActualThemeVariantChanged -= GlobalActualThemeVariantChanged;
             }
             
-
-            _layoutDiagnosticBridge?.Dispose();
-            _layoutDiagnosticBridge = null;
             _backGestureSubscription?.Dispose();
 
             var logicalArgs = new LogicalTreeAttachmentEventArgs(this, this, null);
@@ -863,49 +831,5 @@ namespace Avalonia.Controls
 
             return scaling;
         }
-
-        /// <summary>
-        /// Provides layout pass timing from the layout manager to the renderer, for diagnostics purposes.
-        /// </summary>
-        private sealed class LayoutDiagnosticBridge : IDisposable
-        {
-            private readonly RendererDiagnostics _diagnostics;
-            private readonly LayoutManager _layoutManager;
-            private bool _isHandling;
-
-            public LayoutDiagnosticBridge(RendererDiagnostics diagnostics, LayoutManager layoutManager)
-            {
-                _diagnostics = diagnostics;
-                _layoutManager = layoutManager;
-
-                diagnostics.PropertyChanged += OnDiagnosticsPropertyChanged;
-            }
-
-            public void SetupBridge()
-            {
-                var needsHandling = (_diagnostics.DebugOverlays & RendererDebugOverlays.LayoutTimeGraph) != 0;
-                if (needsHandling != _isHandling)
-                {
-                    _isHandling = needsHandling;
-                    _layoutManager.LayoutPassTimed = needsHandling
-                        ? timing => _diagnostics.LastLayoutPassTiming = timing
-                        : null;
-                }
-            }
-
-            private void OnDiagnosticsPropertyChanged(object? sender, PropertyChangedEventArgs e)
-            {
-                if (e.PropertyName == nameof(RendererDiagnostics.DebugOverlays))
-                {
-                    SetupBridge();
-                }
-            }
-
-            public void Dispose()
-            {
-                _diagnostics.PropertyChanged -= OnDiagnosticsPropertyChanged;
-                _layoutManager.LayoutPassTimed = null;
-            }
-        }
     }
 }

src/Avalonia.Controls/TreeView.cs

@@ -168,7 +168,7 @@ namespace Avalonia.Controls
             item.IsExpanded = true;
 
             if (item.Presenter?.Panel is null)
-                (this.GetVisualRoot() as ILayoutRoot)?.LayoutManager.ExecuteLayoutPass();
+                this.GetLayoutManager()?.ExecuteLayoutPass();
 
             if (item.Presenter?.Panel is { } panel)
             {

src/Avalonia.Controls/VirtualizingStackPanel.cs

@@ -459,7 +459,7 @@ namespace Avalonia.Controls
                 element.BringIntoView();
                 return element;
             }
-            else if (this.GetVisualRoot() is ILayoutRoot root)
+            else if (this.GetLayoutRoot() is {} root)
             {
                 // Create and measure the element to be brought into view. Store it in a field so that
                 // it can be re-used in the layout pass.

src/Avalonia.Controls/Window.cs

@@ -86,7 +86,7 @@ namespace Avalonia.Controls
     /// <summary>
     /// A top-level window.
     /// </summary>
-    public class Window : WindowBase, IFocusScope, ILayoutRoot
+    public class Window : WindowBase, IFocusScope
     {
         private static readonly Lazy<WindowIcon?> s_defaultIcon = new(LoadDefaultIcon);
         private readonly List<(Window child, bool isDialog)> _children = new List<(Window, bool)>();

tests/Avalonia.Controls.UnitTests/ButtonTests.cs

@@ -759,18 +759,9 @@ namespace Avalonia.Controls.UnitTests
             }
         }
 
-        private class TestTopLevel : TopLevel
+        private class TestTopLevel(ITopLevelImpl impl) : TopLevel(impl)
         {
-            private readonly ILayoutManager _layoutManager;
-            public bool IsClosed { get; private set; }
 
-            public TestTopLevel(ITopLevelImpl impl, ILayoutManager? layoutManager = null)
-                : base(impl)
-            {
-                _layoutManager = layoutManager ?? new LayoutManager(this);
-            }
-
-            private protected override ILayoutManager CreateLayoutManager() => _layoutManager;
         }
     }
 }

tests/Avalonia.Controls.UnitTests/CarouselTests.cs

@@ -336,7 +336,7 @@ namespace Avalonia.Controls.UnitTests
 
         private static void Layout(Carousel target)
         {
-            ((ILayoutRoot)target.GetVisualRoot()!).LayoutManager.ExecuteLayoutPass();
+            target.GetLayoutManager()?.ExecuteLayoutPass();
         }
 
         private static IControlTemplate CarouselTemplate()

tests/Avalonia.Controls.UnitTests/ItemsControlTests.cs

@@ -1218,7 +1218,7 @@ namespace Avalonia.Controls.UnitTests
 
         private static void Layout(Control c)
         {
-            (c.GetVisualRoot() as ILayoutRoot)?.LayoutManager.ExecuteLayoutPass();
+            c.GetLayoutManager()?.ExecuteLayoutPass();
         }
 
         private static ContentPresenter GetContainer(ItemsControl target, int index = 0)

tests/Avalonia.Controls.UnitTests/ListBoxTests.cs

@@ -642,7 +642,7 @@ namespace Avalonia.Controls.UnitTests
 
         private static void Layout(Control c)
         {
-            ((ILayoutRoot)c.GetVisualRoot()!).LayoutManager.ExecuteLayoutPass();
+            c.GetLayoutManager()?.ExecuteLayoutPass();
         }
 
         private class Item

tests/Avalonia.Controls.UnitTests/MaskedTextBoxTests.cs

@@ -1002,17 +1002,8 @@ namespace Avalonia.Controls.UnitTests
             }
         }
 
-        private class TestTopLevel : TopLevel
+        private class TestTopLevel(ITopLevelImpl impl) : TopLevel(impl)
         {
-            private readonly ILayoutManager _layoutManager;
-
-            public TestTopLevel(ITopLevelImpl impl, ILayoutManager? layoutManager = null)
-                : base(impl)
-            {
-                _layoutManager = layoutManager ?? new LayoutManager(this);
-            }
-
-            private protected override ILayoutManager CreateLayoutManager() => _layoutManager;
         }
 
         private static Mock<ITopLevelImpl> CreateMockTopLevelImpl()

tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests.cs

@@ -2555,7 +2555,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
         private static void Layout(Control c)
         {
-            ((ILayoutRoot)c.GetVisualRoot()!).LayoutManager.ExecuteLayoutPass();
+            c.GetLayoutManager()?.ExecuteLayoutPass();
         }
 
         private static FuncControlTemplate Template()

tests/Avalonia.Controls.UnitTests/Primitives/SelectingItemsControlTests_Multiple.cs

@@ -1341,7 +1341,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
         private static void Layout(Control c)
         {
-            (c.GetVisualRoot() as ILayoutRoot)?.LayoutManager.ExecuteLayoutPass();
+            c.GetLayoutManager()?.ExecuteLayoutPass();
         }
 
         public static IDisposable Start()

tests/Avalonia.Controls.UnitTests/TabControlTests.cs

@@ -883,18 +883,8 @@ namespace Avalonia.Controls.UnitTests
             };
         }
 
-        private class TestTopLevel : TopLevel
+        private class TestTopLevel(ITopLevelImpl impl) : TopLevel(impl)
         {
-            private readonly ILayoutManager _layoutManager;
-            public bool IsClosed { get; private set; }
-
-            public TestTopLevel(ITopLevelImpl impl, ILayoutManager? layoutManager = null)
-                : base(impl)
-            {
-                _layoutManager = layoutManager ?? new LayoutManager(this);
-            }
-
-            private protected override ILayoutManager CreateLayoutManager() => _layoutManager;
         }
 
         private static void Prepare(TabControl target)

tests/Avalonia.Controls.UnitTests/TextBoxTests.cs

@@ -2284,17 +2284,8 @@ namespace Avalonia.Controls.UnitTests
             }
         }
 
-        private class TestTopLevel : TopLevel
+        private class TestTopLevel(ITopLevelImpl impl) : TopLevel(impl)
         {
-            private readonly ILayoutManager _layoutManager;
-
-            public TestTopLevel(ITopLevelImpl impl, ILayoutManager? layoutManager = null)
-                : base(impl)
-            {
-                _layoutManager = layoutManager ?? new LayoutManager(this);
-            }
-
-            private protected override ILayoutManager CreateLayoutManager() => _layoutManager;
         }
 
         private static Mock<ITopLevelImpl> CreateMockTopLevelImpl()

tests/Avalonia.Controls.UnitTests/TopLevelTests.cs

@@ -82,11 +82,11 @@ namespace Avalonia.Controls.UnitTests
             {
                 var impl = CreateMockTopLevelImpl();
                 
-                var target = new TestTopLevel(impl.Object, Mock.Of<ILayoutManager>());
-
+                var target = new TestTopLevel(impl.Object);
+                
                 // The layout pass should be scheduled by the derived class.
-                var layoutManagerMock = Mock.Get(target.LayoutManager);
-                layoutManagerMock.Verify(x => x.ExecuteLayoutPass(), Times.Never);
+                Assert.Equal(0, target.Measured);
+                Assert.Equal(0, target.Arranged);
             }
         }
 
@@ -254,22 +254,6 @@ namespace Avalonia.Controls.UnitTests
             }
         }
 
-        [Fact]
-        public void Close_Should_Dispose_LayoutManager()
-        {
-            using (UnitTestApplication.Start(TestServices.StyledWindow))
-            {
-                var impl = CreateMockTopLevelImpl(true);
-
-                var layoutManager = new Mock<ILayoutManager>();
-                var target = new TestTopLevel(impl.Object, layoutManager.Object);
-
-                impl.Object.Closed!();
-
-                layoutManager.Verify(x => x.Dispose());
-            }
-        }
-
         [Fact]
         public void Reacts_To_Changes_In_Global_Styles()
         {
@@ -329,18 +313,20 @@ namespace Avalonia.Controls.UnitTests
             return topLevel;
         }
 
-        private class TestTopLevel : TopLevel
+        private class TestTopLevel(ITopLevelImpl impl) : TopLevel(impl)
         {
-            private readonly ILayoutManager _layoutManager;
-            public bool IsClosed { get; private set; }
-
-            public TestTopLevel(ITopLevelImpl impl, ILayoutManager? layoutManager = null)
-                : base(impl)
+            public int Measured, Arranged;
+            protected override Size MeasureCore(Size availableSize)
             {
-                _layoutManager = layoutManager ?? new LayoutManager(this);
+                Measured++;
+                return base.MeasureCore(availableSize);
             }
 
-            private protected override ILayoutManager CreateLayoutManager() => _layoutManager;
+            protected override void ArrangeCore(Rect finalRect)
+            {
+                Arranged++;
+                base.ArrangeCore(finalRect);
+            }
         }
     }
 }

tests/Avalonia.Controls.UnitTests/TransitioningContentControlTests.cs

@@ -377,7 +377,7 @@ namespace Avalonia.Controls.UnitTests
 
         private void Layout(Control c)
         {
-            (c.GetVisualRoot() as ILayoutRoot)?.LayoutManager.ExecuteLayoutPass();
+            c.GetLayoutManager()?.ExecuteLayoutPass();
         }
 
         private class TestTransition : IPageTransition

tests/Avalonia.Controls.UnitTests/TreeViewTests.cs

@@ -1781,7 +1781,7 @@ namespace Avalonia.Controls.UnitTests
 
         private void Layout(Control c)
         {
-            (c.GetVisualRoot() as ILayoutRoot)?.LayoutManager.ExecuteLayoutPass();
+            c.GetLayoutManager()?.ExecuteLayoutPass();
         }
 
         private void ClickContainer(Control container, KeyModifiers modifiers)

tests/Avalonia.Controls.UnitTests/VirtualizingCarouselPanelTests.cs

@@ -344,6 +344,6 @@ namespace Avalonia.Controls.UnitTests
                 });
         }
 
-        private static void Layout(Control c) => ((ILayoutRoot)c.GetVisualRoot()!).LayoutManager.ExecuteLayoutPass();
+        private static void Layout(Control c) => c.GetLayoutManager()?.ExecuteLayoutPass();
     }
 }

tests/Avalonia.Controls.UnitTests/VirtualizingStackPanelTests.cs

@@ -2352,8 +2352,7 @@ namespace Avalonia.Controls.UnitTests
 
         private static void Layout(Control target)
         {
-            var root = (ILayoutRoot?)target.GetVisualRoot();
-            root?.LayoutManager.ExecuteLayoutPass();
+            target.GetLayoutManager()?.ExecuteLayoutPass();
         }
 
         private static IControlTemplate ListBoxItemTemplate()

tests/Avalonia.RenderTests/TestRenderRoot.cs

@@ -5,13 +5,14 @@ using System.Collections.Generic;
 using Avalonia.Controls;
 using Avalonia.Input;
 using Avalonia.Input.TextInput;
+using Avalonia.Layout;
 using Avalonia.Platform;
 using Avalonia.Rendering.Composition;
 
 
 namespace Avalonia.Skia.RenderTests
 {
-    public class TestRenderRoot : Decorator, IPresentationSource, IInputRoot
+    public class TestRenderRoot : Decorator, IPresentationSource, IInputRoot, ILayoutRoot
     {
         private readonly IRenderTarget _renderTarget;
         public Size ClientSize { get; private set; }
@@ -19,6 +20,15 @@ namespace Avalonia.Skia.RenderTests
         IRenderer IPresentationSource.Renderer => Renderer;
         IHitTester IPresentationSource.HitTester => new NullHitTester();
         public IInputRoot InputRoot => this;
+
+        ILayoutRoot IPresentationSource.LayoutRoot => this;
+
+        public double LayoutScaling => 1l;
+
+        public ILayoutManager LayoutManager { get; }
+
+        Layoutable ILayoutRoot.RootVisual => this;
+
         public Visual? RootVisual => this;
         public double RenderScaling { get; }
 
@@ -26,7 +36,8 @@ namespace Avalonia.Skia.RenderTests
         {
             _renderTarget = renderTarget;
             RenderScaling = scaling;
-            
+            LayoutManager = new LayoutManager(this);
+
         }
         
         class NullHitTester : IHitTester

tests/Avalonia.UnitTests/TestRoot.cs

@@ -58,6 +58,11 @@ namespace Avalonia.UnitTests
         public double LayoutScaling { get; set; } = 1;
 
         internal ILayoutManager LayoutManager { get; set; }
+
+        ILayoutRoot IPresentationSource.LayoutRoot => this;
+
+        Layoutable ILayoutRoot.RootVisual => RootElement;
+
         ILayoutManager ILayoutRoot.LayoutManager => LayoutManager;
 
         public Visual? RootVisual => this;