Merge branch 'master' into CompactDensityStyle

src/Avalonia.Controls/Embedding/EmbeddableControlRoot.cs

@@ -25,7 +25,7 @@ namespace Avalonia.Controls.Embedding
         {
             EnsureInitialized();
             ApplyTemplate();
-            LayoutManager.ExecuteInitialLayoutPass(this);
+            LayoutManager.ExecuteInitialLayoutPass();
         }
 
         private void EnsureInitialized()

src/Avalonia.Controls/Embedding/Offscreen/OffscreenTopLevel.cs

@@ -18,7 +18,7 @@ namespace Avalonia.Controls.Embedding.Offscreen
         {
             EnsureInitialized();
             ApplyTemplate();
-            LayoutManager.ExecuteInitialLayoutPass(this);
+            LayoutManager.ExecuteInitialLayoutPass();
         }
 
         private void EnsureInitialized()

src/Avalonia.Controls/TopLevel.cs

@@ -318,7 +318,7 @@ namespace Avalonia.Controls
         /// <summary>
         /// Creates the layout manager for this <see cref="TopLevel" />.
         /// </summary>
-        protected virtual ILayoutManager CreateLayoutManager() => new LayoutManager();
+        protected virtual ILayoutManager CreateLayoutManager() => new LayoutManager(this);
 
         /// <summary>
         /// Handles a paint notification from <see cref="ITopLevelImpl.Resized"/>.
@@ -351,6 +351,7 @@ namespace Avalonia.Controls
             OnClosed(EventArgs.Empty);
             Renderer?.Dispose();
             Renderer = null;
+            LayoutManager?.Dispose();
         }
 
         /// <summary>

src/Avalonia.Controls/Window.cs

@@ -519,7 +519,7 @@ namespace Avalonia.Controls
                 }
             }
 
-            LayoutManager.ExecuteInitialLayoutPass(this);
+            LayoutManager.ExecuteInitialLayoutPass();
 
             using (BeginAutoSizing())
             {
@@ -592,7 +592,7 @@ namespace Avalonia.Controls
                 }
             }
 
-            LayoutManager.ExecuteInitialLayoutPass(this);
+            LayoutManager.ExecuteInitialLayoutPass();
 
             var result = new TaskCompletionSource<TResult>();
 

src/Avalonia.Controls/WindowBase.cs

@@ -162,7 +162,7 @@ namespace Avalonia.Controls
 
                 if (!_hasExecutedInitialLayoutPass)
                 {
-                    LayoutManager.ExecuteInitialLayoutPass(this);
+                    LayoutManager.ExecuteInitialLayoutPass();
                     _hasExecutedInitialLayoutPass = true;
                 }
                 PlatformImpl?.Show();

src/Avalonia.Layout/ILayoutManager.cs

@@ -7,7 +7,7 @@ namespace Avalonia.Layout
     /// <summary>
     /// Manages measuring and arranging of controls.
     /// </summary>
-    public interface ILayoutManager
+    public interface ILayoutManager : IDisposable
     {
         /// <summary>
         /// Raised when the layout manager completes a layout pass.
@@ -35,6 +35,15 @@ namespace Avalonia.Layout
         /// </remarks>
         void ExecuteLayoutPass();
 
+        /// <summary>
+        /// Executes the initial layout pass on a layout root.
+        /// </summary>
+        /// <remarks>
+        /// You should not usually need to call this method explictly, the layout root will call
+        /// it to carry out the initial layout of the control.
+        /// </remarks>
+        void ExecuteInitialLayoutPass();
+
         /// <summary>
         /// Executes the initial layout pass on a layout root.
         /// </summary>
@@ -43,6 +52,7 @@ namespace Avalonia.Layout
         /// You should not usually need to call this method explictly, the layout root will call
         /// it to carry out the initial layout of the control.
         /// </remarks>
+        [Obsolete("Call ExecuteInitialLayoutPass without parameter")]
         void ExecuteInitialLayoutPass(ILayoutRoot root);
     }
 }

src/Avalonia.Layout/LayoutManager.cs

@@ -10,16 +10,19 @@ namespace Avalonia.Layout
     /// <summary>
     /// Manages measuring and arranging of controls.
     /// </summary>
-    public class LayoutManager : ILayoutManager
+    public class LayoutManager : ILayoutManager, IDisposable
     {
+        private readonly ILayoutRoot _owner;
         private readonly LayoutQueue<ILayoutable> _toMeasure = new LayoutQueue<ILayoutable>(v => !v.IsMeasureValid);
         private readonly LayoutQueue<ILayoutable> _toArrange = new LayoutQueue<ILayoutable>(v => !v.IsArrangeValid);
         private readonly Action _executeLayoutPass;
+        private bool _disposed;
         private bool _queued;
         private bool _running;
 
-        public LayoutManager()
+        public LayoutManager(ILayoutRoot owner)
         {
+            _owner = owner ?? throw new ArgumentNullException(nameof(owner));
             _executeLayoutPass = ExecuteLayoutPass;
         }
 
@@ -31,6 +34,11 @@ namespace Avalonia.Layout
             control = control ?? throw new ArgumentNullException(nameof(control));
             Dispatcher.UIThread.VerifyAccess();
 
+            if (_disposed)
+            {
+                return;
+            }
+
             if (!control.IsAttachedToVisualTree)
             {
 #if DEBUG
@@ -41,6 +49,11 @@ namespace Avalonia.Layout
 #endif
             }
 
+            if (control.VisualRoot != _owner)
+            {
+                throw new ArgumentException("Attempt to call InvalidateMeasure on wrong LayoutManager.");
+            }
+
             _toMeasure.Enqueue(control);
             _toArrange.Enqueue(control);
             QueueLayoutPass();
@@ -52,6 +65,11 @@ namespace Avalonia.Layout
             control = control ?? throw new ArgumentNullException(nameof(control));
             Dispatcher.UIThread.VerifyAccess();
 
+            if (_disposed)
+            {
+                return;
+            }
+
             if (!control.IsAttachedToVisualTree)
             {
 #if DEBUG
@@ -62,6 +80,11 @@ namespace Avalonia.Layout
 #endif
             }
 
+            if (control.VisualRoot != _owner)
+            {
+                throw new ArgumentException("Attempt to call InvalidateArrange on wrong LayoutManager.");
+            }
+
             _toArrange.Enqueue(control);
             QueueLayoutPass();
         }
@@ -73,6 +96,11 @@ namespace Avalonia.Layout
 
             Dispatcher.UIThread.VerifyAccess();
 
+            if (_disposed)
+            {
+                return;
+            }
+
             if (!_running)
             {
                 _running = true;
@@ -131,13 +159,18 @@ namespace Avalonia.Layout
         }
 
         /// <inheritdoc/>
-        public virtual void ExecuteInitialLayoutPass(ILayoutRoot root)
+        public virtual void ExecuteInitialLayoutPass()
         {
+            if (_disposed)
+            {
+                return;
+            }
+
             try
             {
                 _running = true;
-                Measure(root);
-                Arrange(root);
+                Measure(_owner);
+                Arrange(_owner);
             }
             finally
             {
@@ -151,6 +184,24 @@ namespace Avalonia.Layout
             ExecuteLayoutPass();
         }
 
+        [Obsolete("Call ExecuteInitialLayoutPass without parameter")]
+        public void ExecuteInitialLayoutPass(ILayoutRoot root)
+        {
+            if (root != _owner)
+            {
+                throw new ArgumentException("ExecuteInitialLayoutPass called with incorrect root.");
+            }
+
+            ExecuteInitialLayoutPass();
+        }
+
+        public void Dispose()
+        {
+            _disposed = true;
+            _toMeasure.Dispose();
+            _toArrange.Dispose();
+        }
+
         private void ExecuteMeasurePass()
         {
             while (_toMeasure.Count > 0)

src/Avalonia.Layout/LayoutQueue.cs

@@ -4,7 +4,7 @@ using System.Collections.Generic;
 
 namespace Avalonia.Layout
 {
-    internal class LayoutQueue<T> : IReadOnlyCollection<T>
+    internal class LayoutQueue<T> : IReadOnlyCollection<T>, IDisposable
     {
         private struct Info
         {
@@ -84,5 +84,12 @@ namespace Avalonia.Layout
 
             _notFinalizedBuffer.Clear();
         }
+
+        public void Dispose()
+        {
+            _inner.Clear();
+            _loopQueueInfo.Clear();
+            _notFinalizedBuffer.Clear();
+        }
     }
 }

tests/Avalonia.Benchmarks/Layout/ControlsBenchmark.cs

@@ -24,7 +24,7 @@ namespace Avalonia.Benchmarks.Layout
                 Renderer = new NullRenderer()
             };
 
-            _root.LayoutManager.ExecuteInitialLayoutPass(_root);
+            _root.LayoutManager.ExecuteInitialLayoutPass();
         }
 
         [Benchmark]

tests/Avalonia.Benchmarks/Layout/Measure.cs

@@ -25,7 +25,7 @@ namespace Avalonia.Benchmarks.Layout
             _controls.Add(panel);
             _controls = ControlHierarchyCreator.CreateChildren(_controls, panel, 3, 5, 5);
 
-            _root.LayoutManager.ExecuteInitialLayoutPass(_root);
+            _root.LayoutManager.ExecuteInitialLayoutPass();
         }
 
         [Benchmark, MethodImpl(MethodImplOptions.NoInlining)]

tests/Avalonia.Benchmarks/Traversal/VisualTreeTraversal.cs

@@ -26,7 +26,7 @@ namespace Avalonia.Benchmarks.Traversal
 
             _shuffledControls = _controls.OrderBy(r => random.Next()).ToList();
 
-            _root.LayoutManager.ExecuteInitialLayoutPass(_root);
+            _root.LayoutManager.ExecuteInitialLayoutPass();
         }
 
         [Benchmark]

tests/Avalonia.Controls.UnitTests/GridTests.cs

@@ -1194,7 +1194,7 @@ namespace Avalonia.Controls.UnitTests
                 Height = 50,
             };
 
-            root.LayoutManager.ExecuteInitialLayoutPass(root);
+            root.LayoutManager.ExecuteInitialLayoutPass();
 
             PrintColumnDefinitions(grids[0]);
             Assert.Equal(5, grids[0].ColumnDefinitions[0].ActualWidth);

tests/Avalonia.Controls.UnitTests/ListBoxTests.cs

@@ -329,7 +329,7 @@ namespace Avalonia.Controls.UnitTests
                     return tb;
                 }, true);
 
-                lm.ExecuteInitialLayoutPass(wnd);
+                lm.ExecuteInitialLayoutPass();
 
                 target.Items = items;
 

tests/Avalonia.Controls.UnitTests/Presenters/ItemsPresenterTests_Virtualization.cs

@@ -232,7 +232,7 @@ namespace Avalonia.Controls.UnitTests.Presenters
                 var scroll = (TestScroller)target.Parent;
 
                 scroll.Width = scroll.Height = 100;
-                scroll.LayoutManager.ExecuteInitialLayoutPass(scroll);
+                scroll.LayoutManager.ExecuteInitialLayoutPass();
 
                 // Ensure than an intermediate measure pass doesn't add more controls than it
                 // should. This can happen if target gets measured with Size.Infinity which
@@ -324,6 +324,11 @@ namespace Avalonia.Controls.UnitTests.Presenters
 
         private class TestScroller : ScrollContentPresenter, IRenderRoot, ILayoutRoot
         {
+            public TestScroller()
+            {
+                LayoutManager = new LayoutManager(this);
+            }
+
             public IRenderer Renderer { get; }
             public Size ClientSize { get; }
             public double RenderScaling => 1;
@@ -332,7 +337,7 @@ namespace Avalonia.Controls.UnitTests.Presenters
 
             public double LayoutScaling => 1;
 
-            public ILayoutManager LayoutManager { get; } = new LayoutManager();
+            public ILayoutManager LayoutManager { get; }
 
             public IRenderTarget CreateRenderTarget() => throw new NotImplementedException();
             public void Invalidate(Rect rect) => throw new NotImplementedException();

tests/Avalonia.Controls.UnitTests/Presenters/ItemsPresenterTests_Virtualization_Simple.cs

@@ -723,7 +723,7 @@ namespace Avalonia.Controls.UnitTests.Presenters
             var scroller = (TestScroller)target.Parent;
 
             scroller.Width = scroller.Height = 100;
-            scroller.LayoutManager.ExecuteInitialLayoutPass(scroller);
+            scroller.LayoutManager.ExecuteInitialLayoutPass();
 
             var last = (target.Items as IList)[10];
 
@@ -740,7 +740,7 @@ namespace Avalonia.Controls.UnitTests.Presenters
             var scroller = (TestScroller)target.Parent;
 
             scroller.Width = scroller.Height = 100;
-            scroller.LayoutManager.ExecuteInitialLayoutPass(scroller);
+            scroller.LayoutManager.ExecuteInitialLayoutPass();
 
             var last = (target.Items as IList)[10];
 
@@ -838,7 +838,7 @@ namespace Avalonia.Controls.UnitTests.Presenters
                 var scroller = (TestScroller)target.Parent;
 
                 scroller.Width = scroller.Height = 100;
-                scroller.LayoutManager.ExecuteInitialLayoutPass(scroller);
+                scroller.LayoutManager.ExecuteInitialLayoutPass();
 
                 var from = target.Panel.Children[5];
                 var result = ((ILogicalScrollable)target).GetControlInDirection(
@@ -855,7 +855,7 @@ namespace Avalonia.Controls.UnitTests.Presenters
                 var scroller = (TestScroller)target.Parent;
 
                 scroller.Width = scroller.Height = 100;
-                scroller.LayoutManager.ExecuteInitialLayoutPass(scroller);
+                scroller.LayoutManager.ExecuteInitialLayoutPass();
 
                 var from = target.Panel.Children[9];
                 var result = ((ILogicalScrollable)target).GetControlInDirection(
@@ -874,7 +874,7 @@ namespace Avalonia.Controls.UnitTests.Presenters
 
                 scroller.Width = 100;
                 scroller.Height = 95;
-                scroller.LayoutManager.ExecuteInitialLayoutPass(scroller);
+                scroller.LayoutManager.ExecuteInitialLayoutPass();
 
                 var from = target.Panel.Children[8];
                 var result = ((ILogicalScrollable)target).GetControlInDirection(
@@ -893,7 +893,7 @@ namespace Avalonia.Controls.UnitTests.Presenters
 
                 scroller.Width = 100;
                 scroller.Height = 95;
-                scroller.LayoutManager.ExecuteInitialLayoutPass(scroller);
+                scroller.LayoutManager.ExecuteInitialLayoutPass();
                 ((ILogicalScrollable)target).Offset = new Vector(0, 11);
 
                 var from = target.Panel.Children[1];
@@ -946,7 +946,7 @@ namespace Avalonia.Controls.UnitTests.Presenters
                 var scroller = (TestScroller)target.Parent;
 
                 scroller.Width = scroller.Height = 100;
-                scroller.LayoutManager.ExecuteInitialLayoutPass(scroller);
+                scroller.LayoutManager.ExecuteInitialLayoutPass();
 
                 var from = target.Panel.Children[5];
                 var result = ((ILogicalScrollable)target).GetControlInDirection(
@@ -963,7 +963,7 @@ namespace Avalonia.Controls.UnitTests.Presenters
                 var scroller = (TestScroller)target.Parent;
 
                 scroller.Width = scroller.Height = 100;
-                scroller.LayoutManager.ExecuteInitialLayoutPass(scroller);
+                scroller.LayoutManager.ExecuteInitialLayoutPass();
 
                 var from = target.Panel.Children[9];
                 var result = ((ILogicalScrollable)target).GetControlInDirection(
@@ -982,7 +982,7 @@ namespace Avalonia.Controls.UnitTests.Presenters
 
                 scroller.Width = 95;
                 scroller.Height = 100;
-                scroller.LayoutManager.ExecuteInitialLayoutPass(scroller);
+                scroller.LayoutManager.ExecuteInitialLayoutPass();
 
                 var from = target.Panel.Children[8];
                 var result = ((ILogicalScrollable)target).GetControlInDirection(
@@ -1001,7 +1001,7 @@ namespace Avalonia.Controls.UnitTests.Presenters
 
                 scroller.Width = 95;
                 scroller.Height = 100;
-                scroller.LayoutManager.ExecuteInitialLayoutPass(scroller);
+                scroller.LayoutManager.ExecuteInitialLayoutPass();
                 ((ILogicalScrollable)target).Offset = new Vector(11, 0);
 
                 var from = target.Panel.Children[1];
@@ -1062,6 +1062,11 @@ namespace Avalonia.Controls.UnitTests.Presenters
 
         private class TestScroller : ScrollContentPresenter, IRenderRoot, ILayoutRoot, ILogicalRoot
         {
+            public TestScroller()
+            {
+                LayoutManager = new LayoutManager(this);
+            }
+
             public IRenderer Renderer { get; }
             public Size ClientSize { get; }
             public double RenderScaling => 1;
@@ -1070,7 +1075,7 @@ namespace Avalonia.Controls.UnitTests.Presenters
 
             public double LayoutScaling => 1;
 
-            public ILayoutManager LayoutManager { get; } = new LayoutManager();
+            public ILayoutManager LayoutManager { get; }
 
             public IRenderTarget CreateRenderTarget() => throw new NotImplementedException();
             public void Invalidate(Rect rect) => throw new NotImplementedException();

tests/Avalonia.Controls.UnitTests/ScrollViewerTests.cs

@@ -158,7 +158,7 @@ namespace Avalonia.Controls.UnitTests
             target.SetValue(ScrollViewer.ViewportProperty, new Size(50, 50));
             target.Offset = new Vector(10, 10);
 
-            root.LayoutManager.ExecuteInitialLayoutPass(root);
+            root.LayoutManager.ExecuteInitialLayoutPass();
 
             target.ScrollChanged += (s, e) =>
             {
@@ -188,7 +188,7 @@ namespace Avalonia.Controls.UnitTests
             target.SetValue(ScrollViewer.ViewportProperty, new Size(50, 50));
             target.Offset = new Vector(10, 10);
 
-            root.LayoutManager.ExecuteInitialLayoutPass(root);
+            root.LayoutManager.ExecuteInitialLayoutPass();
 
             target.ScrollChanged += (s, e) =>
             {
@@ -218,7 +218,7 @@ namespace Avalonia.Controls.UnitTests
             target.SetValue(ScrollViewer.ViewportProperty, new Size(50, 50));
             target.Offset = new Vector(10, 10);
 
-            root.LayoutManager.ExecuteInitialLayoutPass(root);
+            root.LayoutManager.ExecuteInitialLayoutPass();
 
             target.ScrollChanged += (s, e) =>
             {

tests/Avalonia.Controls.UnitTests/TopLevelTests.cs

@@ -106,7 +106,7 @@ namespace Avalonia.Controls.UnitTests
                     }
                 };
 
-                target.LayoutManager.ExecuteInitialLayoutPass(target);
+                target.LayoutManager.ExecuteInitialLayoutPass();
 
                 Assert.Equal(new Rect(0, 0, 321, 432), target.Bounds);
             }
@@ -267,6 +267,23 @@ namespace Avalonia.Controls.UnitTests
             }
         }
 
+        [Fact]
+        public void Close_Should_Dispose_LayoutManager()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var impl = new Mock<ITopLevelImpl>();
+                impl.SetupAllProperties();
+
+                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()
         {
@@ -282,7 +299,7 @@ namespace Avalonia.Controls.UnitTests
                     Content = child,
                 };
 
-                target.LayoutManager.ExecuteInitialLayoutPass(target);
+                target.LayoutManager.ExecuteInitialLayoutPass();
 
                 Assert.Equal(new Thickness(0), child.BorderThickness);
 
@@ -295,7 +312,7 @@ namespace Avalonia.Controls.UnitTests
                 };
 
                 Application.Current.Styles.Add(style);
-                target.LayoutManager.ExecuteInitialLayoutPass(target);
+                target.LayoutManager.ExecuteInitialLayoutPass();
 
                 Assert.Equal(new Thickness(2), child.BorderThickness);
 
@@ -323,7 +340,7 @@ namespace Avalonia.Controls.UnitTests
             public TestTopLevel(ITopLevelImpl impl, ILayoutManager layoutManager = null)
                 : base(impl)
             {
-                _layoutManager = layoutManager ?? new LayoutManager();
+                _layoutManager = layoutManager ?? new LayoutManager(this);
             }
 
             protected override ILayoutManager CreateLayoutManager() => _layoutManager;

tests/Avalonia.Layout.UnitTests/LayoutManagerTests.cs

@@ -13,7 +13,7 @@ namespace Avalonia.Layout.UnitTests
             var control = new LayoutTestControl();
             var root = new LayoutTestRoot { Child = control };
 
-            root.LayoutManager.ExecuteInitialLayoutPass(root);
+            root.LayoutManager.ExecuteInitialLayoutPass();
             control.Measured = control.Arranged = false;
 
             control.InvalidateMeasure();
@@ -23,13 +23,29 @@ namespace Avalonia.Layout.UnitTests
             Assert.True(control.Arranged);
         }
 
+        [Fact]
+        public void Doesnt_Measure_And_Arrange_InvalidateMeasured_Control_When_TopLevel_Is_Not_Visible()
+        {
+            var control = new LayoutTestControl();
+            var root = new LayoutTestRoot { Child = control, IsVisible = false };
+
+            root.LayoutManager.ExecuteInitialLayoutPass();
+            control.Measured = control.Arranged = false;
+
+            control.InvalidateMeasure();
+            root.LayoutManager.ExecuteLayoutPass();
+
+            Assert.False(control.Measured);
+            Assert.False(control.Arranged);
+        }
+
         [Fact]
         public void Arranges_InvalidateArranged_Control()
         {
             var control = new LayoutTestControl();
             var root = new LayoutTestRoot { Child = control };
 
-            root.LayoutManager.ExecuteInitialLayoutPass(root);
+            root.LayoutManager.ExecuteInitialLayoutPass();
             control.Measured = control.Arranged = false;
 
             control.InvalidateArrange();
@@ -45,7 +61,7 @@ namespace Avalonia.Layout.UnitTests
             var control = new LayoutTestControl();
             var root = new LayoutTestRoot();
 
-            root.LayoutManager.ExecuteInitialLayoutPass(root);
+            root.LayoutManager.ExecuteInitialLayoutPass();
             root.Child = control;
             root.Measured = root.Arranged = false;
 
@@ -80,7 +96,7 @@ namespace Avalonia.Layout.UnitTests
             root.DoMeasureOverride = MeasureOverride;
             control1.DoMeasureOverride = MeasureOverride;
             control2.DoMeasureOverride = MeasureOverride;
-            root.LayoutManager.ExecuteInitialLayoutPass(root);
+            root.LayoutManager.ExecuteInitialLayoutPass();
 
             control2.InvalidateMeasure();
             control1.InvalidateMeasure();
@@ -115,7 +131,7 @@ namespace Avalonia.Layout.UnitTests
             root.DoMeasureOverride = MeasureOverride;
             control1.DoMeasureOverride = MeasureOverride;
             control2.DoMeasureOverride = MeasureOverride;
-            root.LayoutManager.ExecuteInitialLayoutPass(root);
+            root.LayoutManager.ExecuteInitialLayoutPass();
 
             control2.InvalidateMeasure();
             root.InvalidateMeasure();
@@ -132,7 +148,7 @@ namespace Avalonia.Layout.UnitTests
             var control = new LayoutTestControl();
             var root = new LayoutTestRoot { Child = control };
 
-            root.LayoutManager.ExecuteInitialLayoutPass(root);
+            root.LayoutManager.ExecuteInitialLayoutPass();
             root.Measured = root.Arranged = false;
             control.Measured = control.Arranged = false;
 
@@ -151,7 +167,7 @@ namespace Avalonia.Layout.UnitTests
             var control = new LayoutTestControl();
             var root = new LayoutTestRoot { Child = control };
 
-            root.LayoutManager.ExecuteInitialLayoutPass(root);
+            root.LayoutManager.ExecuteInitialLayoutPass();
             control.Measured = control.Arranged = false;
 
             control.InvalidateMeasure();
@@ -177,7 +193,7 @@ namespace Avalonia.Layout.UnitTests
                 return new Size(100, 100);
             };
 
-            root.LayoutManager.ExecuteInitialLayoutPass(root);
+            root.LayoutManager.ExecuteInitialLayoutPass();
 
             Assert.Equal(Size.Infinity, availableSize);
         }
@@ -199,7 +215,7 @@ namespace Avalonia.Layout.UnitTests
                 return s;
             };
 
-            root.LayoutManager.ExecuteInitialLayoutPass(root);
+            root.LayoutManager.ExecuteInitialLayoutPass();
             Assert.Equal(new Size(100, 100), arrangeSize);
 
             root.Width = 120;
@@ -225,7 +241,7 @@ namespace Avalonia.Layout.UnitTests
                 }
             };
 
-            root.LayoutManager.ExecuteInitialLayoutPass(root);
+            root.LayoutManager.ExecuteInitialLayoutPass();
             Assert.Equal(new Size(0, 0), root.DesiredSize);
 
             border.Width = 100;
@@ -241,7 +257,7 @@ namespace Avalonia.Layout.UnitTests
             var control = new LayoutTestControl();
             var root = new LayoutTestRoot { Child = control };
 
-            root.LayoutManager.ExecuteInitialLayoutPass(root);
+            root.LayoutManager.ExecuteInitialLayoutPass();
             control.Measured = false;
 
             int cnt = 0;
@@ -272,7 +288,7 @@ namespace Avalonia.Layout.UnitTests
             var control = new LayoutTestControl();
             var root = new LayoutTestRoot { Child = control };
 
-            root.LayoutManager.ExecuteInitialLayoutPass(root);
+            root.LayoutManager.ExecuteInitialLayoutPass();
             control.Arranged = false;
 
             int cnt = 0;
@@ -313,7 +329,7 @@ namespace Avalonia.Layout.UnitTests
             panel.Children.AddRange(nonArrageableTargets);
             panel.Children.AddRange(targets);
 
-            root.LayoutManager.ExecuteInitialLayoutPass(root);
+            root.LayoutManager.ExecuteInitialLayoutPass();
 
             foreach (var c in panel.Children.OfType<LayoutTestControl>())
             {
@@ -347,7 +363,7 @@ namespace Avalonia.Layout.UnitTests
             var control = new LayoutTestControl();
             var root = new LayoutTestRoot { Child = control };
 
-            root.LayoutManager.ExecuteInitialLayoutPass(root);
+            root.LayoutManager.ExecuteInitialLayoutPass();
             control.Measured = false;
 
             control.DoMeasureOverride = (l, s) =>
@@ -380,7 +396,7 @@ namespace Avalonia.Layout.UnitTests
             var root = new LayoutTestRoot { Child = control };
             var count = 0;
 
-            root.LayoutManager.ExecuteInitialLayoutPass(root);
+            root.LayoutManager.ExecuteInitialLayoutPass();
             control.Measured = false;
 
             control.DoMeasureOverride = (l, s) =>
@@ -399,7 +415,7 @@ namespace Avalonia.Layout.UnitTests
 
             root.InvalidateMeasure();
             control.InvalidateMeasure();
-            root.LayoutManager.ExecuteInitialLayoutPass(root);
+            root.LayoutManager.ExecuteInitialLayoutPass();
 
             Assert.Equal(new Size(200, 200), control.Bounds.Size);
             Assert.Equal(new Size(200, 200), control.DesiredSize);

tests/Avalonia.Layout.UnitTests/LayoutableTests.cs

@@ -208,14 +208,12 @@ namespace Avalonia.Layout.UnitTests
         {
             Border border1;
             Border border2;
-            var layoutManager = new LayoutManager();
             var root = new TestRoot
             {
                 Child = border1 = new Border
                 {
                     Child = border2 = new Border(),
                 },
-                LayoutManager = layoutManager,
             };
             var raised = 0;
 
@@ -233,7 +231,7 @@ namespace Avalonia.Layout.UnitTests
             root.Measure(new Size(100, 100));
             root.Arrange(new Rect(0, 0, 100, 100));
             
-            layoutManager.ExecuteLayoutPass();
+            root.LayoutManager.ExecuteLayoutPass();
 
             Assert.Equal(3, raised);
             Assert.Equal(new Rect(0, 0, 100, 100), border1.Bounds);

tests/Avalonia.LeakTests/ControlTests.cs

@@ -44,7 +44,7 @@ namespace Avalonia.LeakTests
                     window.Show();
 
                     // Do a layout and make sure that Canvas gets added to visual tree.
-                    window.LayoutManager.ExecuteInitialLayoutPass(window);
+                    window.LayoutManager.ExecuteInitialLayoutPass();
                     Assert.IsType<Canvas>(window.Presenter.Child);
 
                     // Clear the content and ensure the Canvas is removed.
@@ -82,7 +82,7 @@ namespace Avalonia.LeakTests
                     window.Show();
 
                     // Do a layout and make sure that Canvas gets added to visual tree.
-                    window.LayoutManager.ExecuteInitialLayoutPass(window);
+                    window.LayoutManager.ExecuteInitialLayoutPass();
                     Assert.IsType<Canvas>(window.Find<Canvas>("foo"));
                     Assert.IsType<Canvas>(window.Presenter.Child);
 
@@ -122,7 +122,7 @@ namespace Avalonia.LeakTests
 
                     // Do a layout and make sure that ScrollViewer gets added to visual tree and its 
                     // template applied.
-                    window.LayoutManager.ExecuteInitialLayoutPass(window);
+                    window.LayoutManager.ExecuteInitialLayoutPass();
                     Assert.IsType<ScrollViewer>(window.Presenter.Child);
                     Assert.IsType<Canvas>(((ScrollViewer)window.Presenter.Child).Presenter.Child);
 
@@ -159,7 +159,7 @@ namespace Avalonia.LeakTests
 
                     // Do a layout and make sure that TextBox gets added to visual tree and its 
                     // template applied.
-                    window.LayoutManager.ExecuteInitialLayoutPass(window);
+                    window.LayoutManager.ExecuteInitialLayoutPass();
                     Assert.IsType<TextBox>(window.Presenter.Child);
                     Assert.NotEmpty(window.Presenter.Child.GetVisualChildren());
 
@@ -203,7 +203,7 @@ namespace Avalonia.LeakTests
 
                     // Do a layout and make sure that TextBox gets added to visual tree and its 
                     // Text property set.
-                    window.LayoutManager.ExecuteInitialLayoutPass(window);
+                    window.LayoutManager.ExecuteInitialLayoutPass();
                     Assert.IsType<TextBox>(window.Presenter.Child);
                     Assert.Equal("foo", ((TextBox)window.Presenter.Child).Text);
 
@@ -241,7 +241,7 @@ namespace Avalonia.LeakTests
 
                 // Do a layout and make sure that TextBox gets added to visual tree and its 
                 // template applied.
-                window.LayoutManager.ExecuteInitialLayoutPass(window);
+                window.LayoutManager.ExecuteInitialLayoutPass();
                 Assert.Same(textBox, window.Presenter.Child);
 
                 // Get the border from the TextBox template.
@@ -295,7 +295,7 @@ namespace Avalonia.LeakTests
                     window.Show();
 
                     // Do a layout and make sure that TreeViewItems get realized.
-                    window.LayoutManager.ExecuteInitialLayoutPass(window);
+                    window.LayoutManager.ExecuteInitialLayoutPass();
                     Assert.Single(target.ItemContainerGenerator.Containers);
 
                     // Clear the content and ensure the TreeView is removed.
@@ -329,7 +329,7 @@ namespace Avalonia.LeakTests
                     window.Show();
 
                     // Do a layout and make sure that Slider gets added to visual tree.
-                    window.LayoutManager.ExecuteInitialLayoutPass(window);
+                    window.LayoutManager.ExecuteInitialLayoutPass();
                     Assert.IsType<Slider>(window.Presenter.Child);
 
                     // Clear the content and ensure the Slider is removed.
@@ -403,7 +403,7 @@ namespace Avalonia.LeakTests
 
                     // Do a layout and make sure that Canvas gets added to visual tree with
                     // its render transform.
-                    window.LayoutManager.ExecuteInitialLayoutPass(window);
+                    window.LayoutManager.ExecuteInitialLayoutPass();
                     var canvas = Assert.IsType<Canvas>(window.Presenter.Child);
                     Assert.IsType<RotateTransform>(canvas.RenderTransform);
 
@@ -514,7 +514,7 @@ namespace Avalonia.LeakTests
 
                     window.Show();
 
-                    window.LayoutManager.ExecuteInitialLayoutPass(window);
+                    window.LayoutManager.ExecuteInitialLayoutPass();
                     Assert.IsType<Path>(window.Presenter.Child);
 
                     window.Content = null;

tests/Avalonia.UnitTests/TestRoot.cs

@@ -19,6 +19,8 @@ namespace Avalonia.UnitTests
         public TestRoot()
         {
             Renderer = Mock.Of<IRenderer>();
+            LayoutManager = new LayoutManager(this);
+            IsVisible = true;
         }
 
         public TestRoot(IControl child)
@@ -44,7 +46,7 @@ namespace Avalonia.UnitTests
 
         public double LayoutScaling { get; set; } = 1;
 
-        public ILayoutManager LayoutManager { get; set; } = new LayoutManager();
+        public ILayoutManager LayoutManager { get; set; }
 
         public double RenderScaling => 1;
 

tests/Avalonia.UnitTests/TestTemplatedRoot.cs

@@ -16,6 +16,7 @@ namespace Avalonia.UnitTests
 
         public TestTemplatedRoot()
         {
+            LayoutManager = new LayoutManager(this);
             Template = new FuncControlTemplate<TestTemplatedRoot>((x, scope) => new ContentPresenter
             {
                 Name = "PART_ContentPresenter",
@@ -28,7 +29,7 @@ namespace Avalonia.UnitTests
 
         public double LayoutScaling => 1;
 
-        public ILayoutManager LayoutManager { get; set; } = new LayoutManager();
+        public ILayoutManager LayoutManager { get; set; }
 
         public double RenderScaling => 1;
 

tests/Avalonia.Visuals.UnitTests/Rendering/ImmediateRendererTests.cs

@@ -134,7 +134,7 @@ namespace Avalonia.Visuals.UnitTests.Rendering
                 var root = new TestRoot(child);
                 root.Renderer = new ImmediateRenderer(root);
 
-                root.LayoutManager.ExecuteInitialLayoutPass(root);
+                root.LayoutManager.ExecuteInitialLayoutPass();
 
                 root.Measure(new Size(50, 100));
                 root.Arrange(new Rect(new Size(50, 100)));
@@ -171,7 +171,7 @@ namespace Avalonia.Visuals.UnitTests.Rendering
                 var root = new TestRoot(child);
                 root.Renderer = new ImmediateRenderer(root);
 
-                root.LayoutManager.ExecuteInitialLayoutPass(root);
+                root.LayoutManager.ExecuteInitialLayoutPass();
 
                 root.Measure(new Size(300, 100));
                 root.Arrange(new Rect(new Size(300, 100)));
@@ -222,7 +222,7 @@ namespace Avalonia.Visuals.UnitTests.Rendering
 
                 var root = new TestRoot(rootGrid);
                 root.Renderer = new ImmediateRenderer(root);
-                root.LayoutManager.ExecuteInitialLayoutPass(root);
+                root.LayoutManager.ExecuteInitialLayoutPass();
 
                 var rootSize = new Size(RootWidth, RootHeight);
                 root.Measure(rootSize);
@@ -277,7 +277,7 @@ namespace Avalonia.Visuals.UnitTests.Rendering
 
                 var root = new TestRoot(rootGrid);
                 root.Renderer = new ImmediateRenderer(root);
-                root.LayoutManager.ExecuteInitialLayoutPass(root);
+                root.LayoutManager.ExecuteInitialLayoutPass();
 
                 var rootSize = new Size(RootWidth, RootHeight);
                 root.Measure(rootSize);

tests/Avalonia.Visuals.UnitTests/Rendering/SceneGraph/SceneBuilderTests.cs

@@ -653,7 +653,7 @@ namespace Avalonia.Visuals.UnitTests.Rendering.SceneGraph
                 };
 
                 var layout = tree.LayoutManager;
-                layout.ExecuteInitialLayoutPass(tree);
+                layout.ExecuteInitialLayoutPass();
 
                 var scene = new Scene(tree);
                 var sceneBuilder = new SceneBuilder();
@@ -696,7 +696,7 @@ namespace Avalonia.Visuals.UnitTests.Rendering.SceneGraph
                 };
 
                 var layout = tree.LayoutManager;
-                layout.ExecuteInitialLayoutPass(tree);
+                layout.ExecuteInitialLayoutPass();
 
                 var scene = new Scene(tree);
                 var sceneBuilder = new SceneBuilder();
@@ -744,7 +744,7 @@ namespace Avalonia.Visuals.UnitTests.Rendering.SceneGraph
                 };
 
                 var layout = tree.LayoutManager;
-                layout.ExecuteInitialLayoutPass(tree);
+                layout.ExecuteInitialLayoutPass();
 
                 var scene = new Scene(tree);
                 var sceneBuilder = new SceneBuilder();

tests/Avalonia.Visuals.UnitTests/Rendering/SceneGraph/SceneBuilderTests_Layers.cs

@@ -40,7 +40,7 @@ namespace Avalonia.Visuals.UnitTests.Rendering.SceneGraph
                 };
 
                 var layout = tree.LayoutManager;
-                layout.ExecuteInitialLayoutPass(tree);
+                layout.ExecuteInitialLayoutPass();
 
                 var animation = new BehaviorSubject<double>(0.5);
                 border.Bind(Border.OpacityProperty, animation, BindingPriority.Animation);
@@ -105,7 +105,7 @@ namespace Avalonia.Visuals.UnitTests.Rendering.SceneGraph
                 };
 
                 var layout = tree.LayoutManager;
-                layout.ExecuteInitialLayoutPass(tree);
+                layout.ExecuteInitialLayoutPass();
 
                 var animation = new BehaviorSubject<double>(0.5);
                 border.Bind(Border.OpacityProperty, animation, BindingPriority.Animation);
@@ -147,7 +147,7 @@ namespace Avalonia.Visuals.UnitTests.Rendering.SceneGraph
                 };
 
                 var layout = tree.LayoutManager;
-                layout.ExecuteInitialLayoutPass(tree);
+                layout.ExecuteInitialLayoutPass();
 
                 var animation = new BehaviorSubject<double>(0.5);
                 border.Bind(Border.OpacityProperty, animation, BindingPriority.Animation);
@@ -197,7 +197,7 @@ namespace Avalonia.Visuals.UnitTests.Rendering.SceneGraph
                 };
 
                 var layout = tree.LayoutManager;
-                layout.ExecuteInitialLayoutPass(tree);
+                layout.ExecuteInitialLayoutPass();
 
                 var animation = new BehaviorSubject<double>(0.5);
                 border.Bind(Border.OpacityProperty, animation, BindingPriority.Animation);
@@ -241,7 +241,7 @@ namespace Avalonia.Visuals.UnitTests.Rendering.SceneGraph
                 };
 
                 var layout = tree.LayoutManager;
-                layout.ExecuteInitialLayoutPass(tree);
+                layout.ExecuteInitialLayoutPass();
 
                 var animation = new BehaviorSubject<double>(0.5);
                 border.Bind(Border.OpacityProperty, animation, BindingPriority.Animation);