Introduce PresentationSource, move some responsibilities from TopLevel (#20624)

* Extracted IInputRoot out of TopLevel

* Move some input handling out of TopLevel

* Remove old class, make layout manager private

* Removed IRenderRoot

* Make VisualTreeAttachmentEventArgs a bit more sensible

* Move ILayoutRoot to PresentationSource

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

* Updated some VisualRoot / GetVisualRoot usages

* Updated more XxxRoot usages

* More Root usages

* Addressed review

* Hurr-durr xml

* More fixes

* Maybe fix android compilation

* API diff

* Yet another cast

* I had to use MSIL analysis to detect those casts

* Fixed automation

* Fix PointerOverPreProcessor

* Fix?

* Removed yet another cast to Visual

* The amount of  random downcasts is astonishing

* Maybe fix mac

* Addressed review

api/Avalonia.nupkg.xml

@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <!-- https://learn.microsoft.com/dotnet/fundamentals/package-validation/diagnostic-ids -->
 <Suppressions xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
   <Suppression>
@@ -109,6 +109,42 @@
     <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
     <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0001</DiagnosticId>
+    <Target>T:Avalonia.Input.IKeyboardNavigationHandler</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0001</DiagnosticId>
+    <Target>T:Avalonia.Input.KeyboardNavigationHandler</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0001</DiagnosticId>
+    <Target>T:Avalonia.Input.TextInput.ITextInputMethodRoot</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0001</DiagnosticId>
+    <Target>T:Avalonia.Layout.IEmbeddedLayoutRoot</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0001</DiagnosticId>
+    <Target>T:Avalonia.Layout.ILayoutRoot</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0001</DiagnosticId>
+    <Target>T:Avalonia.Layout.LayoutManager</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0001</DiagnosticId>
     <Target>T:Avalonia.Media.Fonts.FontFamilyLoader</Target>
@@ -151,6 +187,24 @@
     <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
     <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0001</DiagnosticId>
+    <Target>T:Avalonia.Rendering.IHitTester</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0001</DiagnosticId>
+    <Target>T:Avalonia.Rendering.IRenderer</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0001</DiagnosticId>
+    <Target>T:Avalonia.Rendering.IRenderRoot</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0001</DiagnosticId>
     <Target>T:Avalonia.Styling.IStyleable</Target>
@@ -391,6 +445,42 @@
     <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
     <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0001</DiagnosticId>
+    <Target>T:Avalonia.Input.IKeyboardNavigationHandler</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0001</DiagnosticId>
+    <Target>T:Avalonia.Input.KeyboardNavigationHandler</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0001</DiagnosticId>
+    <Target>T:Avalonia.Input.TextInput.ITextInputMethodRoot</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0001</DiagnosticId>
+    <Target>T:Avalonia.Layout.IEmbeddedLayoutRoot</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0001</DiagnosticId>
+    <Target>T:Avalonia.Layout.ILayoutRoot</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0001</DiagnosticId>
+    <Target>T:Avalonia.Layout.LayoutManager</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0001</DiagnosticId>
     <Target>T:Avalonia.Media.Fonts.FontFamilyLoader</Target>
@@ -433,6 +523,24 @@
     <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
     <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0001</DiagnosticId>
+    <Target>T:Avalonia.Rendering.IHitTester</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0001</DiagnosticId>
+    <Target>T:Avalonia.Rendering.IRenderer</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0001</DiagnosticId>
+    <Target>T:Avalonia.Rendering.IRenderRoot</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0001</DiagnosticId>
     <Target>T:Avalonia.Styling.IStyleable</Target>
@@ -685,6 +793,42 @@
     <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
     <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.Input.IInputRoot.get_KeyboardNavigationHandler</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.Input.IInputRoot.get_PlatformSettings</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.Input.IInputRoot.get_PointerOverElement</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.Input.IInputRoot.get_ShowAccessKeys</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.Input.IInputRoot.set_PointerOverElement(Avalonia.Input.IInputElement)</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.Input.IInputRoot.set_ShowAccessKeys(System.Boolean)</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0002</DiagnosticId>
     <Target>M:Avalonia.Input.IKeyboardNavigationHandler.Move(Avalonia.Input.IInputElement,Avalonia.Input.NavigationDirection,Avalonia.Input.KeyModifiers)</Target>
@@ -973,12 +1117,30 @@
     <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
     <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.Rendering.SceneInvalidatedEventArgs.#ctor(Avalonia.Rendering.IRenderRoot,Avalonia.Rect)</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.Rendering.SceneInvalidatedEventArgs.get_RenderRoot</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0002</DiagnosticId>
     <Target>M:Avalonia.Utilities.AvaloniaResourcesIndexReaderWriter.WriteResources(System.IO.Stream,System.Collections.Generic.List{System.ValueTuple{System.String,System.Int32,System.Func{System.IO.Stream}}})</Target>
     <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
     <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.Visual.get_VisualRoot</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0002</DiagnosticId>
     <Target>M:Avalonia.Visuals.Platform.PathGeometryContext.ArcTo(Avalonia.Point,Avalonia.Size,System.Double,System.Boolean,Avalonia.Media.SweepDirection)</Target>
@@ -1003,6 +1165,24 @@
     <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
     <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.VisualTree.VisualExtensions.GetVisualRoot(Avalonia.Visual)</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.VisualTreeAttachmentEventArgs.#ctor(Avalonia.Visual,Avalonia.Rendering.IRenderRoot)</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.VisualTreeAttachmentEventArgs.get_Root</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0002</DiagnosticId>
     <Target>F:Avalonia.Controls.ContextMenu.PlacementModeProperty</Target>
@@ -1063,6 +1243,12 @@
     <Left>baseline/Avalonia/lib/net10.0/Avalonia.Controls.dll</Left>
     <Right>current/Avalonia/lib/net10.0/Avalonia.Controls.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>F:Avalonia.Controls.TopLevel.PointerOverElementProperty</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Controls.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Controls.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0002</DiagnosticId>
     <Target>M:Avalonia.AppBuilder.get_LifetimeOverride</Target>
@@ -1333,6 +1519,30 @@
     <Left>baseline/Avalonia/lib/net10.0/Avalonia.Controls.dll</Left>
     <Right>current/Avalonia/lib/net10.0/Avalonia.Controls.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.Controls.TopLevel.#ctor(Avalonia.Platform.ITopLevelImpl,Avalonia.IAvaloniaDependencyResolver)</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Controls.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Controls.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.Controls.TopLevel.get_PlatformSettings</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Controls.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Controls.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.Controls.TopLevel.StartRendering</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Controls.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Controls.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.Controls.TopLevel.StopRendering</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Controls.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Controls.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0002</DiagnosticId>
     <Target>M:Avalonia.Controls.TreeView.get_ItemContainerGenerator</Target>
@@ -1603,6 +1813,42 @@
     <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
     <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.Input.IInputRoot.get_KeyboardNavigationHandler</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.Input.IInputRoot.get_PlatformSettings</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.Input.IInputRoot.get_PointerOverElement</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.Input.IInputRoot.get_ShowAccessKeys</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.Input.IInputRoot.set_PointerOverElement(Avalonia.Input.IInputElement)</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.Input.IInputRoot.set_ShowAccessKeys(System.Boolean)</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0002</DiagnosticId>
     <Target>M:Avalonia.Input.IKeyboardNavigationHandler.Move(Avalonia.Input.IInputElement,Avalonia.Input.NavigationDirection,Avalonia.Input.KeyModifiers)</Target>
@@ -1891,12 +2137,30 @@
     <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
     <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.Rendering.SceneInvalidatedEventArgs.#ctor(Avalonia.Rendering.IRenderRoot,Avalonia.Rect)</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.Rendering.SceneInvalidatedEventArgs.get_RenderRoot</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0002</DiagnosticId>
     <Target>M:Avalonia.Utilities.AvaloniaResourcesIndexReaderWriter.WriteResources(System.IO.Stream,System.Collections.Generic.List{System.ValueTuple{System.String,System.Int32,System.Func{System.IO.Stream}}})</Target>
     <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
     <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.Visual.get_VisualRoot</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0002</DiagnosticId>
     <Target>M:Avalonia.Visuals.Platform.PathGeometryContext.ArcTo(Avalonia.Point,Avalonia.Size,System.Double,System.Boolean,Avalonia.Media.SweepDirection)</Target>
@@ -1921,6 +2185,24 @@
     <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
     <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.VisualTree.VisualExtensions.GetVisualRoot(Avalonia.Visual)</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.VisualTreeAttachmentEventArgs.#ctor(Avalonia.Visual,Avalonia.Rendering.IRenderRoot)</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.VisualTreeAttachmentEventArgs.get_Root</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0002</DiagnosticId>
     <Target>F:Avalonia.Controls.ContextMenu.PlacementModeProperty</Target>
@@ -1981,6 +2263,12 @@
     <Left>baseline/Avalonia/lib/net8.0/Avalonia.Controls.dll</Left>
     <Right>current/Avalonia/lib/net8.0/Avalonia.Controls.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>F:Avalonia.Controls.TopLevel.PointerOverElementProperty</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Controls.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Controls.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0002</DiagnosticId>
     <Target>M:Avalonia.AppBuilder.get_LifetimeOverride</Target>
@@ -2251,6 +2539,30 @@
     <Left>baseline/Avalonia/lib/net8.0/Avalonia.Controls.dll</Left>
     <Right>current/Avalonia/lib/net8.0/Avalonia.Controls.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.Controls.TopLevel.#ctor(Avalonia.Platform.ITopLevelImpl,Avalonia.IAvaloniaDependencyResolver)</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Controls.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Controls.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.Controls.TopLevel.get_PlatformSettings</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Controls.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Controls.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.Controls.TopLevel.StartRendering</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Controls.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Controls.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0002</DiagnosticId>
+    <Target>M:Avalonia.Controls.TopLevel.StopRendering</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Controls.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Controls.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0002</DiagnosticId>
     <Target>M:Avalonia.Controls.TreeView.get_ItemContainerGenerator</Target>
@@ -2839,6 +3151,12 @@
     <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
     <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0008</DiagnosticId>
+    <Target>T:Avalonia.Input.IInputRoot</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Base.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0008</DiagnosticId>
     <Target>T:Avalonia.Media.ImmediateDrawingContext</Target>
@@ -2881,6 +3199,12 @@
     <Left>baseline/Avalonia/lib/net10.0/Avalonia.Controls.dll</Left>
     <Right>current/Avalonia/lib/net10.0/Avalonia.Controls.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0008</DiagnosticId>
+    <Target>T:Avalonia.Controls.Embedding.EmbeddableControlRoot</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Controls.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Controls.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0008</DiagnosticId>
     <Target>T:Avalonia.Controls.Embedding.Offscreen.OffscreenTopLevelImplBase</Target>
@@ -2893,6 +3217,36 @@
     <Left>baseline/Avalonia/lib/net10.0/Avalonia.Controls.dll</Left>
     <Right>current/Avalonia/lib/net10.0/Avalonia.Controls.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0008</DiagnosticId>
+    <Target>T:Avalonia.Controls.Primitives.OverlayPopupHost</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Controls.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Controls.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0008</DiagnosticId>
+    <Target>T:Avalonia.Controls.Primitives.PopupRoot</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Controls.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Controls.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0008</DiagnosticId>
+    <Target>T:Avalonia.Controls.TopLevel</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Controls.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Controls.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0008</DiagnosticId>
+    <Target>T:Avalonia.Controls.Window</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Controls.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Controls.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0008</DiagnosticId>
+    <Target>T:Avalonia.Controls.WindowBase</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Controls.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Controls.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0008</DiagnosticId>
     <Target>T:Avalonia.Platform.IPopupImpl</Target>
@@ -2917,6 +3271,12 @@
     <Left>baseline/Avalonia/lib/net10.0/Avalonia.Controls.dll</Left>
     <Right>current/Avalonia/lib/net10.0/Avalonia.Controls.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0008</DiagnosticId>
+    <Target>T:Avalonia.Dialogs.AboutAvaloniaDialog</Target>
+    <Left>baseline/Avalonia/lib/net10.0/Avalonia.Dialogs.dll</Left>
+    <Right>current/Avalonia/lib/net10.0/Avalonia.Dialogs.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0008</DiagnosticId>
     <Target>T:Avalonia.Metal.IMetalDevice</Target>
@@ -2959,6 +3319,12 @@
     <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
     <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0008</DiagnosticId>
+    <Target>T:Avalonia.Input.IInputRoot</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Base.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Base.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0008</DiagnosticId>
     <Target>T:Avalonia.Media.ImmediateDrawingContext</Target>
@@ -3001,6 +3367,12 @@
     <Left>baseline/Avalonia/lib/net8.0/Avalonia.Controls.dll</Left>
     <Right>current/Avalonia/lib/net8.0/Avalonia.Controls.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0008</DiagnosticId>
+    <Target>T:Avalonia.Controls.Embedding.EmbeddableControlRoot</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Controls.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Controls.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0008</DiagnosticId>
     <Target>T:Avalonia.Controls.Embedding.Offscreen.OffscreenTopLevelImplBase</Target>
@@ -3013,6 +3385,36 @@
     <Left>baseline/Avalonia/lib/net8.0/Avalonia.Controls.dll</Left>
     <Right>current/Avalonia/lib/net8.0/Avalonia.Controls.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0008</DiagnosticId>
+    <Target>T:Avalonia.Controls.Primitives.OverlayPopupHost</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Controls.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Controls.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0008</DiagnosticId>
+    <Target>T:Avalonia.Controls.Primitives.PopupRoot</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Controls.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Controls.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0008</DiagnosticId>
+    <Target>T:Avalonia.Controls.TopLevel</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Controls.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Controls.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0008</DiagnosticId>
+    <Target>T:Avalonia.Controls.Window</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Controls.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Controls.dll</Right>
+  </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0008</DiagnosticId>
+    <Target>T:Avalonia.Controls.WindowBase</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Controls.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Controls.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0008</DiagnosticId>
     <Target>T:Avalonia.Platform.IPopupImpl</Target>
@@ -3037,6 +3439,12 @@
     <Left>baseline/Avalonia/lib/net8.0/Avalonia.Controls.dll</Left>
     <Right>current/Avalonia/lib/net8.0/Avalonia.Controls.dll</Right>
   </Suppression>
+  <Suppression>
+    <DiagnosticId>CP0008</DiagnosticId>
+    <Target>T:Avalonia.Dialogs.AboutAvaloniaDialog</Target>
+    <Left>baseline/Avalonia/lib/net8.0/Avalonia.Dialogs.dll</Left>
+    <Right>current/Avalonia/lib/net8.0/Avalonia.Dialogs.dll</Right>
+  </Suppression>
   <Suppression>
     <DiagnosticId>CP0008</DiagnosticId>
     <Target>T:Avalonia.Metal.IMetalDevice</Target>

samples/ControlCatalog/MainView.xaml.cs

@@ -45,7 +45,7 @@ namespace ControlCatalog
 
         private void Decorations_SelectionChanged(object? sender, SelectionChangedEventArgs e)
         {
-            if (VisualRoot is Window window && e.AddedItems.Count > 0 && e.AddedItems[0] is SystemDecorations systemDecorations)
+            if (TopLevel.GetTopLevel(this) is Window window && e.AddedItems.Count > 0 && e.AddedItems[0] is SystemDecorations systemDecorations)
             {
                 window.SystemDecorations = systemDecorations;
             }
@@ -78,7 +78,7 @@ namespace ControlCatalog
         {
             base.OnAttachedToVisualTree(e);
 
-            if (VisualRoot is Window window)
+            if (TopLevel.GetTopLevel(this) is Window window)
                 Decorations.SelectedIndex = (int)window.SystemDecorations;
 
             var insets = TopLevel.GetTopLevel(this)!.InsetsManager;

samples/ControlCatalog/ViewModels/ContextPageViewModel.cs

@@ -49,7 +49,7 @@ namespace ControlCatalog.ViewModels
 
         public async Task Open()
         {
-            var window = View?.GetVisualRoot() as Window;
+            var window = TopLevel.GetTopLevel(View) as Window;
             if (window == null)
                 return;
 

samples/ControlCatalog/ViewModels/MenuPageViewModel.cs

@@ -69,7 +69,7 @@ namespace ControlCatalog.ViewModels
 
         public async Task Open()
         {
-            var window = View?.GetVisualRoot() as Window;
+            var window = TopLevel.GetTopLevel(View) as Window;
             if (window == null)
                 return;
             var result = await window.StorageProvider.OpenFilePickerAsync(new Avalonia.Platform.Storage.FilePickerOpenOptions() { AllowMultiple = true });

samples/GpuInterop/DrawingSurfaceDemoBase.cs

@@ -71,12 +71,12 @@ public abstract class DrawingSurfaceDemoBase : Control, IGpuDemo
     void UpdateFrame()
     {
         _updateQueued = false;
-        var root = this.GetVisualRoot();
-        if (root == null)
+        var source = this.GetPresentationSource();
+        if (source == null)
             return;
         
         _visual!.Size = new (Bounds.Width, Bounds.Height);
-        var size = PixelSize.FromSize(Bounds.Size, root.RenderScaling);
+        var size = PixelSize.FromSize(Bounds.Size, source.RenderScaling);
         RenderFrame(size);
         if (SupportsDisco && Disco > 0)
             QueueNextFrame();

src/Android/Avalonia.Android/Platform/Input/AvaloniaInputConnection.cs

@@ -157,8 +157,7 @@ namespace Avalonia.Android.Platform.Input
                     }
                 case ImeAction.Next:
                     {
-                        FocusManager.GetFocusManager(_toplevel.InputRoot)?
-                            .TryMoveFocus(NavigationDirection.Next);
+                        ((FocusManager?)_toplevel.InputRoot?.FocusManager)?.TryMoveFocus(NavigationDirection.Next);
                         break;
                     }
             }

src/Avalonia.Base/Input/AccessKeyHandler.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using Avalonia.Controls.Primitives;
 using Avalonia.Interactivity;
 using Avalonia.LogicalTree;
 using Avalonia.VisualTree;
@@ -30,6 +31,12 @@ namespace Avalonia.Input
                 RoutingStrategies.Bubble,
                 typeof(AccessKeyHandler));
 
+        /// <summary>
+        /// Defines the ShowAccessKey attached property.
+        /// </summary>
+        public static readonly AttachedProperty<bool> ShowAccessKeyProperty =
+            AvaloniaProperty.RegisterAttached<AccessKeyHandler, Visual, bool>("ShowAccessKey", inherits: true);
+        
         /// <summary>
         /// The registered access keys.
         /// </summary>
@@ -40,7 +47,7 @@ namespace Avalonia.Input
         /// <summary>
         /// The window to which the handler belongs.
         /// </summary>
-        private IInputRoot? _owner;
+        private InputElement? _owner;
 
         /// <summary>
         /// Whether access keys are currently being shown;
@@ -96,7 +103,7 @@ namespace Avalonia.Input
         /// <remarks>
         /// This method can only be called once, typically by the owner itself on creation.
         /// </remarks>
-        public void SetOwner(IInputRoot owner)
+        public void SetOwner(InputElement owner)
         {
             if (_owner != null)
             {
@@ -113,7 +120,7 @@ namespace Avalonia.Input
             OnSetOwner(owner);
         }
 
-        protected virtual void OnSetOwner(IInputRoot owner)
+        protected virtual void OnSetOwner(InputElement owner)
         {
         }
 
@@ -159,6 +166,9 @@ namespace Avalonia.Input
             }
         }
 
+        static void SetShowAccessKeys(AvaloniaObject target, bool value) =>
+            target.SetValue(ShowAccessKeyProperty, value);
+        
         /// <summary>
         /// Called when a key is pressed in the owner window.
         /// </summary>
@@ -188,7 +198,7 @@ namespace Avalonia.Input
 
                     // When Alt is pressed without a main menu, or with a closed main menu, show
                     // access key markers in the window (i.e. "_File").
-                    _owner!.ShowAccessKeys = _showingAccessKeys = isFocusWithinOwner;
+                    SetShowAccessKeys(_owner!, _showingAccessKeys = isFocusWithinOwner);
                 }
                 else
                 {
@@ -265,7 +275,7 @@ namespace Avalonia.Input
         {
             if (_showingAccessKeys)
             {
-                _owner!.ShowAccessKeys = false;
+                SetShowAccessKeys(_owner!, false);
             }
         }
 
@@ -275,12 +285,12 @@ namespace Avalonia.Input
         private void CloseMenu()
         {
             MainMenu!.Close();
-            _owner!.ShowAccessKeys = _showingAccessKeys = false;
+            SetShowAccessKeys(_owner!, _showingAccessKeys = false);
         }
 
         private void MainMenuClosed(object? sender, EventArgs e)
         {
-            _owner!.ShowAccessKeys = false;
+            SetShowAccessKeys(_owner!, false);
         }
 
         /// <summary>
@@ -444,7 +454,7 @@ namespace Avalonia.Input
         /// </summary>
         /// <param name="owner">The owner to check.</param>
         /// <returns>If focused element is decendant of owner <c>true</c>, otherwise <c>false</c>. </returns>
-        private static bool IsFocusWithinOwner(IInputRoot owner)
+        private static bool IsFocusWithinOwner(IInputElement owner)
         {
             var focusedElement = KeyboardDevice.Instance?.FocusedElement;
             if (focusedElement is not InputElement inputElement)

src/Avalonia.Base/Input/DragDropDevice.cs

@@ -16,7 +16,7 @@ namespace Avalonia.Input
         
         private static Interactive? GetTarget(IInputRoot root, Point local)
         {
-            var hit = root.InputHitTest(local) as Visual;
+            var hit = root.RootElement?.InputHitTest(local) as Visual;
             var target = hit?.GetSelfAndVisualAncestors()?.OfType<Interactive>()?.FirstOrDefault();
             if (target != null && DragDrop.GetAllowDrop(target))
                 return target;
@@ -35,7 +35,7 @@ namespace Avalonia.Input
             if (target == null)
                 return DragDropEffects.None;
 
-            var p = ((Visual)inputRoot).TranslatePoint(point, target);
+            var p = (inputRoot.RootElement).TranslatePoint(point, target);
 
             if (!p.HasValue)
                 return DragDropEffects.None;

src/Avalonia.Base/Input/FocusManager.cs

@@ -52,6 +52,11 @@ namespace Avalonia.Input
             _contentRoot = contentRoot;
         }
         
+        internal void SetContentRoot(IInputElement? contentRoot)
+        {
+            _contentRoot = contentRoot;
+        }
+
         private IInputElement? Current => KeyboardDevice.Instance?.FocusedElement;
 
         private XYFocus _xyFocus = new();
@@ -163,9 +168,10 @@ namespace Avalonia.Input
         /// </summary>
         internal static FocusManager? GetFocusManager(IInputElement? element)
         {
+            
             // Element might not be a visual, and not attached to the root.
             // But IFocusManager is always expected to be a FocusManager. 
-            return (FocusManager?)((element as Visual)?.VisualRoot as IInputRoot)?.FocusManager
+            return (FocusManager?)(element as Visual)?.GetInputRoot()?.FocusManager
                 // In our unit tests some elements might not have a root. Remove when we migrate to headless tests.
                 ?? (FocusManager?)AvaloniaLocator.Current.GetService<IFocusManager>();
         }

src/Avalonia.Base/Input/Gestures.cs

@@ -257,7 +257,7 @@ namespace Avalonia.Input
                     s_lastPressPoint = e.GetPosition((Visual)source);
                     s_holdCancellationToken = new CancellationTokenSource();
                     var token = s_holdCancellationToken.Token;
-                    var settings = ((IInputRoot?)visual.GetVisualRoot())?.PlatformSettings;
+                    var settings = visual.GetPlatformSettings();
 
                     if (settings != null)
                     {
@@ -298,7 +298,7 @@ namespace Avalonia.Input
                 source is Interactive i)
                 {
                     var point = e.GetCurrentPoint((Visual)target);
-                    var settings = ((IInputRoot?)i.GetVisualRoot())?.PlatformSettings;
+                    var settings = i.GetPlatformSettings();
                     var tapSize = settings?.GetTapSize(point.Pointer.Type) ?? new Size(4, 4);
                     var tapRect = new Rect(s_lastPressPoint, new Size())
                         .Inflate(new Thickness(tapSize.Width, tapSize.Height));
@@ -340,7 +340,6 @@ namespace Avalonia.Input
                     if (e.Pointer == s_gestureState?.Pointer && source is Interactive i)
                     {
                         var point = e.GetCurrentPoint((Visual)target);
-                        var settings = ((IInputRoot?)i.GetVisualRoot())?.PlatformSettings;
                         var holdSize = new Size(4, 4);
                         var holdRect = new Rect(s_lastPressPoint, new Size())
                             .Inflate(new Thickness(holdSize.Width, holdSize.Height));

src/Avalonia.Base/Input/IAccessKeyHandler.cs

@@ -19,7 +19,7 @@ namespace Avalonia.Input
         /// <remarks>
         /// This method can only be called once, typically by the owner itself on creation.
         /// </remarks>
-        void SetOwner(IInputRoot owner);
+        void SetOwner(InputElement owner);
 
         /// <summary>
         /// Registers an input element to be associated with an access key.

src/Avalonia.Base/Input/IInputRoot.cs

@@ -1,3 +1,4 @@
+using Avalonia.Input.TextInput;
 using Avalonia.Metadata;
 using Avalonia.Platform;
 
@@ -6,38 +7,24 @@ namespace Avalonia.Input
     /// <summary>
     /// Defines the interface for top-level input elements.
     /// </summary>
-    [NotClientImplementable]
-    public interface IInputRoot : IInputElement
+    [PrivateApi]
+    public interface IInputRoot
     {
-        /// <summary>
-        /// Gets or sets the keyboard navigation handler.
-        /// </summary>
-        IKeyboardNavigationHandler? KeyboardNavigationHandler { get; }
-
         /// <summary>
         /// Gets focus manager of the root.
         /// </summary>
         /// <remarks>
         /// Focus manager can be null only if window wasn't initialized yet.
         /// </remarks>
-        IFocusManager? FocusManager { get; }
-        
-        /// <summary>
-        /// Represents a contract for accessing top-level platform-specific settings.
-        /// </summary>
-        /// <remarks>
-        /// PlatformSettings can be null only if window wasn't initialized yet.
-        /// </remarks>
-        IPlatformSettings? PlatformSettings { get; }
+        public IFocusManager? FocusManager { get; }
         
         /// <summary>
         /// Gets or sets the input element that the pointer is currently over.
         /// </summary>
-        IInputElement? PointerOverElement { get; set; }
+        internal IInputElement? PointerOverElement { get; set; }
         
-        /// <summary>
-        /// Gets or sets a value indicating whether access keys are shown in the window.
-        /// </summary>
-        bool ShowAccessKeys { get; set; }
+        internal ITextInputMethodImpl? InputMethod { get; }
+        
+        internal InputElement RootElement { get; }
     }
 }

src/Avalonia.Base/Input/IKeyboardNavigationHandler.cs

@@ -6,7 +6,7 @@ namespace Avalonia.Input
     /// Defines the interface for classes that handle keyboard navigation for a window.
     /// </summary>
     [Unstable]
-    public interface IKeyboardNavigationHandler
+    internal interface IKeyboardNavigationHandler
     {
         /// <summary>
         /// Sets the owner of the keyboard navigation handler.
@@ -16,7 +16,7 @@ namespace Avalonia.Input
         /// This method can only be called once, typically by the owner itself on creation.
         /// </remarks>
         [PrivateApi]
-        void SetOwner(IInputRoot owner);
+        void SetOwner(InputElement owner);
 
         /// <summary>
         /// Moves the focus in the specified direction.

src/Avalonia.Base/Input/InputElement.cs

@@ -583,7 +583,9 @@ namespace Avalonia.Input
 
             if (IsFocused)
             {
-                FocusManager.GetFocusManager(e.Root as IInputElement)?.ClearFocusOnElementRemoved(this, e.Parent);
+                var root = e.AttachmentPoint ?? e.RootVisual;
+                ((FocusManager?)e.PresentationSource.InputRoot.FocusManager)
+                    ?.ClearFocusOnElementRemoved(this, root);
             }
 
             IsKeyboardFocusWithin = false;

src/Avalonia.Base/Input/KeyboardDevice.cs

@@ -191,15 +191,15 @@ namespace Avalonia.Input
                     // Clear keyboard focus from currently focused element
                     if (FocusedElement != null &&
                         (!((Visual)FocusedElement).IsAttachedToVisualTree ||
-                         _focusedRoot != ((Visual?)element)?.VisualRoot as IInputRoot) &&
+                         _focusedRoot != ((Visual?)element)?.GetInputRoot()) &&
                         _focusedRoot != null)
                     {
-                        ClearChildrenFocusWithin(_focusedRoot, true);
+                        ClearChildrenFocusWithin(_focusedRoot.RootElement, true);
                     }
 
                     SetIsFocusWithin(FocusedElement, element);
                     _focusedElement = element;
-                    _focusedRoot = ((Visual?)_focusedElement)?.VisualRoot as IInputRoot;
+                    _focusedRoot = (_focusedElement as Visual)?.GetInputRoot();
 
                     interactive?.RaiseEvent(new RoutedEventArgs(InputElement.LostFocusEvent));
 
@@ -225,7 +225,7 @@ namespace Avalonia.Input
             if(e.Handled)
                 return;
 
-            var element = FocusedElement ?? e.Root;
+            var element = FocusedElement ?? e.Root.RootElement;
 
             if (e is RawKeyEventArgs keyInput)
             {

src/Avalonia.Base/Input/KeyboardNavigationHandler.cs

@@ -10,13 +10,12 @@ namespace Avalonia.Input
     /// <summary>
     /// Handles keyboard navigation for a window.
     /// </summary>
-    [Unstable]
-    public sealed class KeyboardNavigationHandler : IKeyboardNavigationHandler
+    internal sealed class KeyboardNavigationHandler : IKeyboardNavigationHandler
     {
         /// <summary>
         /// The window to which the handler belongs.
         /// </summary>
-        private IInputRoot? _owner;
+        private InputElement? _owner;
         
         /// <summary>
         /// Sets the owner of the keyboard navigation handler.
@@ -26,7 +25,7 @@ namespace Avalonia.Input
         /// This method can only be called once, typically by the owner itself on creation.
         /// </remarks>
         [PrivateApi]
-        public void SetOwner(IInputRoot owner)
+        public void SetOwner(InputElement owner)
         {
             if (_owner != null)
             {
@@ -56,7 +55,7 @@ namespace Avalonia.Input
 
         private static IInputElement? GetNextPrivate(
             IInputElement? element,
-            IInputRoot? owner,
+            InputElement? owner,
             NavigationDirection direction,
             KeyDeviceType? keyDeviceType)
         {

src/Avalonia.Base/Input/MouseDevice.cs

@@ -135,20 +135,20 @@ namespace Avalonia.Input
             return new PointerPointProperties(args.InputModifiers, args.Type.ToUpdateKind());
         }
 
-        private bool MouseDown(IMouseDevice device, ulong timestamp, IInputElement root, Point p,
+        private bool MouseDown(IMouseDevice device, ulong timestamp, IInputRoot root, Point p,
             PointerPointProperties properties,
             KeyModifiers inputModifiers, IInputElement? hitTest)
         {
             device = device ?? throw new ArgumentNullException(nameof(device));
             root = root ?? throw new ArgumentNullException(nameof(root));
 
-            var source = _pointer.Captured ?? root.InputHitTest(p);
+            var source = _pointer.Captured ?? root.RootElement.InputHitTest(p);
 
             if (source != null)
             {
                 _pointer.Capture(source, CaptureSource.Implicit);
 
-                var settings = ((IInputRoot?)(source as Interactive)?.GetVisualRoot())?.PlatformSettings;
+                var settings = (source as Interactive)?.GetPlatformSettings();
                 if (settings is not null)
                 {
                     var doubleClickTime = settings.GetDoubleTapTime(PointerType.Mouse).TotalMilliseconds;
@@ -166,7 +166,7 @@ namespace Avalonia.Input
                 }
 
                 _lastMouseDownButton = properties.PointerUpdateKind.GetMouseButton();
-                var e = new PointerPressedEventArgs(source, _pointer, (Visual)root, p, timestamp, properties, inputModifiers, _clickCount);
+                var e = new PointerPressedEventArgs(source, _pointer, root.RootElement, p, timestamp, properties, inputModifiers, _clickCount);
                 source.RaiseEvent(e);
                 return e.Handled;
             }
@@ -185,7 +185,7 @@ namespace Avalonia.Input
 
             if (source is object)
             {
-                var e = new PointerEventArgs(InputElement.PointerMovedEvent, source, _pointer, (Visual)root,
+                var e = new PointerEventArgs(InputElement.PointerMovedEvent, source, _pointer, root.RootElement,
                     p, timestamp, properties, inputModifiers, intermediatePoints);
 
                 if (_pointer.CapturedGestureRecognizer is GestureRecognizer gestureRecognizer)
@@ -209,7 +209,7 @@ namespace Avalonia.Input
 
             if (source is not null)
             {
-                var e = new PointerReleasedEventArgs(source, _pointer, (Visual)root, p, timestamp, props, inputModifiers,
+                var e = new PointerReleasedEventArgs(source, _pointer, root.RootElement, p, timestamp, props, inputModifiers,
                     _lastMouseDownButton);
 
                 try
@@ -244,7 +244,7 @@ namespace Avalonia.Input
 
             if (source is not null)
             {
-                var e = new PointerWheelEventArgs(source, _pointer, (Visual)root, p, timestamp, props, inputModifiers, delta);
+                var e = new PointerWheelEventArgs(source, _pointer, root.RootElement, p, timestamp, props, inputModifiers, delta);
 
                 source?.RaiseEvent(e);
                 return e.Handled;
@@ -264,7 +264,7 @@ namespace Avalonia.Input
             if (source != null)
             {
                 var e = new PointerDeltaEventArgs(Gestures.PointerTouchPadGestureMagnifyEvent, source,
-                    _pointer, (Visual)root, p, timestamp, props, inputModifiers, delta);
+                    _pointer, root.RootElement, p, timestamp, props, inputModifiers, delta);
 
                 source?.RaiseEvent(e);
                 return e.Handled;
@@ -284,7 +284,7 @@ namespace Avalonia.Input
             if (source != null)
             {
                 var e = new PointerDeltaEventArgs(Gestures.PointerTouchPadGestureRotateEvent, source,
-                    _pointer, (Visual)root, p, timestamp, props, inputModifiers, delta);
+                    _pointer, root.RootElement, p, timestamp, props, inputModifiers, delta);
 
                 source?.RaiseEvent(e);
                 return e.Handled;
@@ -304,7 +304,7 @@ namespace Avalonia.Input
             if (source != null)
             {
                 var e = new PointerDeltaEventArgs(Gestures.PointerTouchPadGestureSwipeEvent, source, 
-                    _pointer, (Visual)root, p, timestamp, props, inputModifiers, delta);
+                    _pointer, root.RootElement, p, timestamp, props, inputModifiers, delta);
 
                 source?.RaiseEvent(e);
                 return e.Handled;

src/Avalonia.Base/Input/Navigation/XYFocus.FindElements.cs

@@ -105,12 +105,11 @@ public partial class XYFocus
     
     private static bool IsOccluded(InputElement element, Rect elementBounds)
     {
-        // if (element is CHyperlink hyperlink)
-        // {
-        //     element = hyperlink.GetContainingFrameworkElement();
-        // }
+        // TODO: The check for bounds is no longer correct
         
-        var root = (InputElement)element.GetVisualRoot()!;
+        var root = (InputElement?)element.VisualRoot;
+        if (root == null)
+            return true;
         
         // Check if the element is within the visible area of the window
         var visibleBounds = new Rect(0, 0, root.Bounds.Width, root.Bounds.Height);

src/Avalonia.Base/Input/Navigation/XYFocus.Impl.cs

@@ -117,7 +117,9 @@ public partial class XYFocus
     {
         if (element == null) return null;
 
-        var root = (InputElement)element.GetVisualRoot()!;
+        var root = (InputElement?)element.VisualRoot;
+        if (root == null)
+            return null;
         var isRightToLeft = element.FlowDirection == FlowDirection.RightToLeft;
         var mode = GetStrategy(element, direction, xyFocusOptions.NavigationStrategyOverride);
 

src/Avalonia.Base/Input/PenDevice.cs

@@ -97,7 +97,7 @@ namespace Avalonia.Input
         }
 
         private bool PenDown(Pointer pointer, ulong timestamp,
-            IInputElement root, Point p, PointerPointProperties properties,
+            IInputRoot root, Point p, PointerPointProperties properties,
             KeyModifiers inputModifiers, IInputElement? hitTest)
         {
             var source = pointer.Captured ?? hitTest;
@@ -105,7 +105,7 @@ namespace Avalonia.Input
             if (source != null)
             {
                 pointer.Capture(source);
-                var settings = ((IInputRoot?)(source as Interactive)?.GetVisualRoot())?.PlatformSettings;
+                var settings = (source as Interactive)?.GetPlatformSettings();
                 if (settings is not null)
                 {
                     var doubleClickTime = settings.GetDoubleTapTime(PointerType.Pen).TotalMilliseconds;
@@ -123,7 +123,7 @@ namespace Avalonia.Input
                 }
 
                 _lastMouseDownButton = properties.PointerUpdateKind.GetMouseButton();
-                var e = new PointerPressedEventArgs(source, pointer, (Visual)root, p, timestamp, properties, inputModifiers, _clickCount);
+                var e = new PointerPressedEventArgs(source, pointer, root.RootElement, p, timestamp, properties, inputModifiers, _clickCount);
                 source.RaiseEvent(e);
                 return e.Handled;
             }
@@ -140,7 +140,7 @@ namespace Avalonia.Input
 
             if (source is not null)
             {
-                var e = new PointerEventArgs(InputElement.PointerMovedEvent, source, pointer, (Visual)root,
+                var e = new PointerEventArgs(InputElement.PointerMovedEvent, source, pointer, root.RootElement,
                     p, timestamp, properties, inputModifiers, intermediatePoints);
 
                 if (pointer.CapturedGestureRecognizer is GestureRecognizer gestureRecognizer)
@@ -154,14 +154,14 @@ namespace Avalonia.Input
         }
 
         private bool PenUp(Pointer pointer, ulong timestamp,
-            IInputElement root, Point p, PointerPointProperties properties,
+            IInputRoot root, Point p, PointerPointProperties properties,
             KeyModifiers inputModifiers, IInputElement? hitTest)
         {
             var source = pointer.CapturedGestureRecognizer?.Target ?? pointer.Captured ?? hitTest;
             
             if (source is not null)
             {
-                var e = new PointerReleasedEventArgs(source, pointer, (Visual)root, p, timestamp, properties, inputModifiers,
+                var e = new PointerReleasedEventArgs(source, pointer, root.RootElement, p, timestamp, properties, inputModifiers,
                     _lastMouseDownButton);
 
                 try

src/Avalonia.Base/Input/Pointer.cs

@@ -108,14 +108,14 @@ namespace Avalonia.Input
             }
         }
 
-        static IInputElement? GetNextCapture(Visual parent)
+        static IInputElement? GetNextCapture(Visual? parent)
         {
             return parent as IInputElement ?? parent.FindAncestorOfType<IInputElement>();
         }
 
         private void OnCaptureDetached(object? sender, VisualTreeAttachmentEventArgs e)
         {
-            Capture(GetNextCapture(e.Parent));
+            Capture(GetNextCapture(e.AttachmentPoint));
         }
 
 

src/Avalonia.Base/Input/PointerOverPreProcessor.cs

@@ -38,7 +38,7 @@ namespace Avalonia.Input
                 // occurred.
                 //
                 // Solve this by updating the last known pointer position when a drag event occurs.
-                _lastKnownPosition = ((Visual)_inputRoot).PointToScreen(dragArgs.Location);
+                _lastKnownPosition = _inputRoot.RootElement.PointToScreen(dragArgs.Location);
             }
 
             else if (value is RawPointerEventArgs args
@@ -64,7 +64,7 @@ namespace Avalonia.Input
                             args.InputModifiers.ToKeyModifiers());
                     }
                 }
-                else if (args.Type is RawPointerEventType.TouchBegin or RawPointerEventType.TouchUpdate && args.Root is Visual visual)
+                else if (args.Type is RawPointerEventType.TouchBegin or RawPointerEventType.TouchUpdate && args.Root.RootElement is {} visual)
                 {
                     _lastKnownPosition = visual.PointToScreen(args.Position);
                 }
@@ -99,12 +99,12 @@ namespace Avalonia.Input
                 if (dirtyRect.Contains(clientPoint))
                 {
                     var element = GetEffectivePointerOverElement(
-                        _inputRoot.InputHitTest(clientPoint),
+                        _inputRoot.RootElement.InputHitTest(clientPoint),
                         pointer.Captured);
 
                     SetPointerOver(pointer, _inputRoot, element, 0, clientPoint, PointerPointProperties.None, KeyModifiers.None);
                 }
-                else if (!((Visual)_inputRoot).Bounds.Contains(clientPoint))
+                else if (!_inputRoot.RootElement.Bounds.Contains(clientPoint))
                 {
                     ClearPointerOver(pointer, _inputRoot, 0, clientPoint, PointerPointProperties.None, KeyModifiers.None);
                 }
@@ -140,16 +140,16 @@ namespace Avalonia.Input
             // so GetPosition won't return invalid values.
 #pragma warning disable CS0618
             var e = new PointerEventArgs(InputElement.PointerExitedEvent, element, pointer,
-                position.HasValue ? root as Visual : null, position.HasValue ? position.Value : default,
+                position.HasValue ? root.RootElement : null, position.HasValue ? position.Value : default,
                 timestamp, properties, inputModifiers);
 #pragma warning restore CS0618
 
             if (element is Visual v && !v.IsAttachedToVisualTree)
             {
                 // element has been removed from visual tree so do top down cleanup
-                if (root.IsPointerOver)
+                if (root.RootElement.IsPointerOver)
                 {
-                    ClearChildrenPointerOver(e, root, true);
+                    ClearChildrenPointerOver(e, root.RootElement, true);
                 }
             }
             while (element != null)
@@ -191,7 +191,7 @@ namespace Avalonia.Input
             ulong timestamp, Point position, PointerPointProperties properties, KeyModifiers inputModifiers)
         {
             var pointerOverElement = root.PointerOverElement;
-            var screenPosition = ((Visual)root).PointToScreen(position);
+            var screenPosition = (root.RootElement).PointToScreen(position);
             _lastKnownPosition = screenPosition;
 
             if (element != pointerOverElement)
@@ -229,7 +229,7 @@ namespace Avalonia.Input
             el = root.PointerOverElement;
 
 #pragma warning disable CS0618
-            var e = new PointerEventArgs(InputElement.PointerExitedEvent, el, pointer, (Visual)root, position,
+            var e = new PointerEventArgs(InputElement.PointerExitedEvent, el, pointer, root.RootElement, position,
                 timestamp, properties, inputModifiers);
 #pragma warning restore CS0618
             if (el is Visual v && branch != null && !v.IsAttachedToVisualTree)
@@ -265,7 +265,7 @@ namespace Avalonia.Input
 
         private static Point PointToClient(IInputRoot root, PixelPoint p)
         {
-            return ((Visual)root).PointToClient(p);
+            return (root.RootElement).PointToClient(p);
         }
     }
 }

src/Avalonia.Base/Input/TextInput/ITextInputMethodImpl.cs

@@ -10,10 +10,4 @@ namespace Avalonia.Input.TextInput
         void SetOptions(TextInputOptions options);
         void Reset();
     }
-    
-    [NotClientImplementable]
-    public interface ITextInputMethodRoot : IInputRoot
-    {
-        ITextInputMethodImpl? InputMethod { get; }
-    }
 }

src/Avalonia.Base/Input/TextInput/InputMethodManager.cs

@@ -132,7 +132,7 @@ namespace Avalonia.Input.TextInput
                 InputMethod.AddTextInputMethodClientRequeryRequestedHandler(_visualRoot,
                     TextInputMethodClientRequeryRequested);
             
-            var inputMethod = ((element as Visual)?.VisualRoot as ITextInputMethodRoot)?.InputMethod;
+            var inputMethod = ((element as Visual)?.GetInputRoot())?.InputMethod;
 
             if (_im != inputMethod)
             {

src/Avalonia.Base/Input/TouchDevice.cs

@@ -51,7 +51,7 @@ namespace Avalonia.Input
                 pointer.Capture(hit);
             }
 
-            var target = pointer.Captured ?? args.InputHitTestResult.firstEnabledAncestor ?? args.Root;
+            var target = pointer.Captured ?? args.InputHitTestResult.firstEnabledAncestor ?? args.Root.RootElement;
             var gestureTarget = pointer.CapturedGestureRecognizer?.Target;
             var updateKind = args.Type.ToUpdateKind();
             var keyModifier = args.InputModifiers.ToKeyModifiers();
@@ -66,7 +66,7 @@ namespace Avalonia.Input
                 }
                 else
                 {
-                    var settings = ((IInputRoot?)(target as Interactive)?.GetVisualRoot())?.PlatformSettings;
+                    var settings = (target as Interactive)?.GetPlatformSettings();
                     if (settings is not null)
                     {
                         var doubleClickTime = settings.GetDoubleTapTime(PointerType.Touch).TotalMilliseconds;
@@ -86,7 +86,7 @@ namespace Avalonia.Input
                 }
 
                 target.RaiseEvent(new PointerPressedEventArgs(target, pointer,
-                    (Visual)args.Root, args.Position, ev.Timestamp,
+                    args.Root.RootElement, args.Position, ev.Timestamp,
                     new PointerPointProperties(GetModifiers(args.InputModifiers, true), updateKind, args.Point),
                     keyModifier, _clickCount));
             }
@@ -98,7 +98,7 @@ namespace Avalonia.Input
                 {
                     target = gestureTarget ?? target;
                     var e = new PointerReleasedEventArgs(target, pointer,
-                            (Visual)args.Root, args.Position, ev.Timestamp,
+                            args.Root.RootElement, args.Position, ev.Timestamp,
                             new PointerPointProperties(GetModifiers(args.InputModifiers, false), updateKind, args.Point),
                             keyModifier, MouseButton.Left);
                     if (gestureTarget != null)
@@ -127,7 +127,7 @@ namespace Avalonia.Input
             if (args.Type == RawPointerEventType.TouchUpdate)
             {
                 target = gestureTarget ?? target;
-                var e = new PointerEventArgs(InputElement.PointerMovedEvent, target, pointer!, (Visual)args.Root,
+                var e = new PointerEventArgs(InputElement.PointerMovedEvent, target, pointer!, args.Root.RootElement,
                     args.Position, ev.Timestamp,
                     new PointerPointProperties(GetModifiers(args.InputModifiers, true), updateKind, args.Point),
                     keyModifier, args.IntermediatePoints);

src/Avalonia.Base/Layout/IEmbeddedLayoutRoot.cs

@@ -1,10 +0,0 @@
-namespace Avalonia.Layout
-{
-    /// <summary>
-    /// A special layout root with enforced size for Arrange pass
-    /// </summary>
-    public interface IEmbeddedLayoutRoot : ILayoutRoot
-    {
-        Size AllocatedSize { get; }
-    }
-}

src/Avalonia.Base/Layout/ILayoutManager.cs

@@ -6,7 +6,6 @@ namespace Avalonia.Layout
     /// <summary>
     /// Manages measuring and arranging of controls.
     /// </summary>
-    [PrivateApi]
     public interface ILayoutManager : IDisposable
     {
         /// <summary>

src/Avalonia.Base/Layout/ILayoutRoot.cs

@@ -5,22 +5,18 @@ namespace Avalonia.Layout
     /// <summary>
     /// Defines the root of a layoutable tree.
     /// </summary>
-    [NotClientImplementable]
-    public interface ILayoutRoot
+    internal interface ILayoutRoot
     {
-        /// <summary>
-        /// The size available to lay out the controls.
-        /// </summary>
-        Size ClientSize { get; }
-
         /// <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
 
@@ -17,11 +18,10 @@ namespace Avalonia.Layout
     /// <summary>
     /// Manages measuring and arranging of controls.
     /// </summary>
-    [PrivateApi]
-    public class LayoutManager : ILayoutManager, IDisposable
+    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();
@@ -34,7 +34,7 @@ namespace Avalonia.Layout
 
         public LayoutManager(ILayoutRoot owner)
         {
-            _owner = owner as Layoutable ?? throw new ArgumentNullException(nameof(owner));
+            _owner = owner;
             _invokeOnRender = ExecuteQueuedLayoutPass;
         }
 
@@ -63,7 +63,7 @@ namespace Avalonia.Layout
 #endif
             }
 
-            if (control.VisualRoot != _owner)
+            if (control.GetLayoutRoot() != _owner)
             {
                 throw new ArgumentException("Attempt to call InvalidateMeasure on wrong LayoutManager.");
             }
@@ -93,7 +93,7 @@ namespace Avalonia.Layout
 #endif
             }
 
-            if (control.VisualRoot != _owner)
+            if (control.GetLayoutRoot() != _owner)
             {
                 throw new ArgumentException("Attempt to call InvalidateArrange on wrong LayoutManager.");
             }
@@ -188,9 +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
             {
@@ -300,7 +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);
                 }
@@ -329,9 +332,7 @@ namespace Avalonia.Layout
 
             if (!control.IsArrangeValid)
             {
-                if (control is IEmbeddedLayoutRoot embeddedRoot)
-                    control.Arrange(new Rect(embeddedRoot.AllocatedSize));
-                else 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;
                 }
@@ -220,7 +220,8 @@ namespace Avalonia.Layout
         /// You should not usually need to call this method explictly, the layout manager will
         /// schedule layout passes itself.
         /// </remarks>
-        public void UpdateLayout() => (this.GetVisualRoot() as ILayoutRoot)?.LayoutManager?.ExecuteLayoutPass();
+        
+        public void UpdateLayout() => this.GetLayoutManager()?.ExecuteLayoutPass();
 
         /// <summary>
         /// Gets or sets the width of the element.
@@ -448,7 +449,7 @@ namespace Avalonia.Layout
 
                 if (IsAttachedToVisualTree)
                 {
-                    (VisualRoot as ILayoutRoot)?.LayoutManager.InvalidateMeasure(this);
+                    this.GetLayoutManager()?.InvalidateMeasure(this);
                     InvalidateVisual();
                 }
                 OnMeasureInvalidated();
@@ -465,7 +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();
             }
         }
@@ -793,7 +794,7 @@ namespace Avalonia.Layout
                 _isAttachingToVisualTree = false;
             }
 
-            if (e.Root is ILayoutRoot r)
+            if (this.GetLayoutRoot() is {} r)
             {
                 if (_layoutUpdated is object)
                 {
@@ -809,7 +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)
                 {
@@ -852,7 +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/Composition/CompositingRenderer.cs

@@ -20,7 +20,7 @@ namespace Avalonia.Rendering.Composition;
 /// </summary>
 internal class CompositingRenderer : IRendererWithCompositor, IHitTester
 {
-    private readonly IRenderRoot _root;
+    private readonly IPresentationSource _root;
     private readonly Compositor _compositor;
     private readonly RenderDataDrawingContext _recorder;
     private readonly HashSet<Visual> _dirty = new();
@@ -48,13 +48,12 @@ internal class CompositingRenderer : IRendererWithCompositor, IHitTester
     /// <param name="surfaces">
     /// A function returning the list of native platform's surfaces that can be consumed by rendering subsystems.
     /// </param>
-    public CompositingRenderer(IRenderRoot root, Compositor compositor, Func<IEnumerable<object>> surfaces)
+    public CompositingRenderer(IPresentationSource root, Compositor compositor, Func<IEnumerable<object>> surfaces)
     {
         _root = root;
         _compositor = compositor;
         _recorder = new(compositor);
         CompositionTarget = compositor.CreateCompositionTarget(surfaces);
-        CompositionTarget.Root = ((Visual)root).AttachToCompositor(compositor);
         _update = Update;
         Diagnostics = new RendererDiagnostics();
         Diagnostics.PropertyChanged += OnDiagnosticsPropertyChanged;
@@ -188,13 +187,13 @@ internal class CompositingRenderer : IRendererWithCompositor, IHitTester
             commit.Rendered.ContinueWith(_ => Dispatcher.UIThread.Post(() =>
             {
                 _queuedSceneInvalidation = false;
-                SceneInvalidated?.Invoke(this, new SceneInvalidatedEventArgs(_root, new Rect(_root.ClientSize)));
+                SceneInvalidated?.Invoke(this, new SceneInvalidatedEventArgs(new Rect(_root.ClientSize)));
             }, DispatcherPriority.Input), CancellationToken.None, TaskContinuationOptions.ExecuteSynchronously, TaskScheduler.Default);
         }
     }
 
     public void TriggerSceneInvalidatedForUnitTests(Rect rect) =>
-        SceneInvalidated?.Invoke(this, new SceneInvalidatedEventArgs(_root, rect));
+        SceneInvalidated?.Invoke(this, new SceneInvalidatedEventArgs(rect));
     
     private void Update()
     {

src/Avalonia.Base/Rendering/Composition/ElementCompositionPreview.cs

@@ -25,7 +25,7 @@ public static class ElementComposition
             throw new InvalidOperationException("Composition visuals belong to different compositor instances");
         
         visual.ChildCompositionVisual = compositionVisual;
-        visual.GetVisualRoot()?.Renderer.RecalculateChildren(visual);
+        visual.GetPresentationSource()?.Renderer.RecalculateChildren(visual);
     }
 
     /// <summary>

src/Avalonia.Base/Rendering/IPresentationSource.cs

@@ -0,0 +1,46 @@
+using System;
+using Avalonia.Input;
+using Avalonia.Layout;
+using Avalonia.Metadata;
+using Avalonia.Platform;
+
+namespace Avalonia.Rendering;
+
+// This interface serves two purposes:
+// 1) User-facing API (public members)
+// 2) A way to provide PresentationSource APIs to Avalonia.Base from Avalonia.Controls
+//    without cyclic references (internal members)
+/// <summary>
+/// Represents the host of the visual tree. On desktop platforms this is typically backed by a native window.
+/// </summary>
+[NotClientImplementable]
+public interface IPresentationSource
+{
+    /// <summary>
+    /// The current root of the visual tree
+    /// </summary>
+    public Visual? RootVisual { get; }
+    
+    /// <summary>
+    /// The scaling factor to use in rendering.
+    /// </summary>
+    public double RenderScaling { get; }
+    
+    internal IPlatformSettings? PlatformSettings { get; }
+    
+    internal IRenderer Renderer { get; }
+    
+    internal IHitTester HitTester { get; }
+    
+    internal IInputRoot InputRoot { get; }
+
+    internal ILayoutRoot LayoutRoot { get; }
+    
+    /// <summary>
+    /// Gets the client size of the window.
+    /// </summary>
+    internal Size ClientSize { get; }
+
+    internal PixelPoint PointToScreen(Point point);
+    internal Point PointToClient(PixelPoint point);
+}

src/Avalonia.Base/Rendering/IRenderRoot.cs

@@ -1,42 +0,0 @@
-using Avalonia.Metadata;
-
-namespace Avalonia.Rendering
-{
-    /// <summary>
-    /// Represents the root of a renderable tree.
-    /// </summary>
-    [NotClientImplementable]
-    public interface IRenderRoot
-    {
-        /// <summary>
-        /// Gets the client size of the window.
-        /// </summary>
-        Size ClientSize { get; }
-
-        /// <summary>
-        /// Gets the renderer for the window.
-        /// </summary>
-        public IRenderer Renderer { get; }
-        
-        public IHitTester HitTester { get; }
-
-        /// <summary>
-        /// The scaling factor to use in rendering.
-        /// </summary>
-        double RenderScaling { get; }
-
-        /// <summary>
-        /// Converts a point from screen to client coordinates.
-        /// </summary>
-        /// <param name="point">The point in screen device coordinates.</param>
-        /// <returns>The point in client coordinates.</returns>
-        Point PointToClient(PixelPoint point);
-
-        /// <summary>
-        /// Converts a point from client to screen coordinates.
-        /// </summary>
-        /// <param name="point">The point in client coordinates.</param>
-        /// <returns>The point in screen device coordinates.</returns>
-        PixelPoint PointToScreen(Point point);
-    }
-}

src/Avalonia.Base/Rendering/IRenderer.cs

@@ -10,7 +10,7 @@ namespace Avalonia.Rendering
     /// Defines the interface for a renderer.
     /// </summary>
     [PrivateApi]
-    public interface IRenderer : IDisposable
+    internal interface IRenderer : IDisposable
     {
         /// <summary>
         /// Gets a value indicating whether the renderer should draw specific diagnostics.
@@ -75,7 +75,7 @@ namespace Avalonia.Rendering
     }
 
     [PrivateApi]
-    public interface IHitTester
+    internal interface IHitTester
     {
         /// <summary>
         /// Hit tests a location to find the visuals at the specified point.

src/Avalonia.Base/Rendering/SceneInvalidatedEventArgs.cs

@@ -12,13 +12,9 @@ namespace Avalonia.Rendering
         /// <summary>
         /// Initializes a new instance of the <see cref="SceneInvalidatedEventArgs"/> class.
         /// </summary>
-        /// <param name="root">The render root that has been updated.</param>
         /// <param name="dirtyRect">The updated area.</param>
-        public SceneInvalidatedEventArgs(
-            IRenderRoot root,
-            Rect dirtyRect)
+        public SceneInvalidatedEventArgs(Rect dirtyRect)
         {
-            RenderRoot = root;
             DirtyRect = dirtyRect;
         }
 
@@ -27,9 +23,5 @@ namespace Avalonia.Rendering
         /// </summary>
         public Rect DirtyRect { get; }
 
-        /// <summary>
-        /// Gets the render root that has been invalidated.
-        /// </summary>
-        public IRenderRoot RenderRoot { get; }
     }
 }

src/Avalonia.Base/Visual.cs

@@ -6,10 +6,12 @@ using System.Collections.Specialized;
 using Avalonia.Collections;
 using Avalonia.Data;
 using Avalonia.Diagnostics;
+using Avalonia.Input;
 using Avalonia.Logging;
 using Avalonia.LogicalTree;
 using Avalonia.Media;
 using Avalonia.Metadata;
+using Avalonia.Platform;
 using Avalonia.Reactive;
 using Avalonia.Rendering;
 using Avalonia.Rendering.Composition;
@@ -124,7 +126,7 @@ namespace Avalonia
                 (s, h) => s.Invalidated -= h);
 
         private Rect _bounds;
-        private IRenderRoot? _visualRoot;
+        internal IPresentationSource? PresentationSource { get; private set; }
         private Visual? _visualParent;
         private bool _hasMirrorTransform;
         private TargetWeakEventSubscriber<Visual, EventArgs>? _affectsRenderWeakSubscriber;
@@ -154,8 +156,6 @@ namespace Avalonia
         /// </summary>
         public Visual()
         {
-            _visualRoot = this as IRenderRoot;
-
             // Disable transitions until we're added to the visual tree.
             DisableTransitions();
 
@@ -339,7 +339,9 @@ namespace Avalonia
         /// <summary>
         /// Gets the root of the visual tree, if the control is attached to a visual tree.
         /// </summary>
-        protected internal IRenderRoot? VisualRoot => _visualRoot;
+        protected internal Visual? VisualRoot => PresentationSource?.RootVisual;
+
+        internal IInputRoot? GetInputRoot() => PresentationSource?.InputRoot;
 
         internal RenderOptions RenderOptions
         {
@@ -366,7 +368,7 @@ namespace Avalonia
         /// <summary>
         /// Gets a value indicating whether this control is attached to a visual root.
         /// </summary>
-        internal bool IsAttachedToVisualTree => VisualRoot != null;
+        internal bool IsAttachedToVisualTree => this.PresentationSource != null;
 
         /// <summary>
         /// Gets the control's parent visual.
@@ -409,7 +411,7 @@ namespace Avalonia
         /// </summary>
         public void InvalidateVisual()
         {
-            VisualRoot?.Renderer.AddDirty(this);
+            PresentationSource?.Renderer.AddDirty(this);
         }
 
         /// <summary>
@@ -514,7 +516,7 @@ namespace Avalonia
         protected override void LogicalChildrenCollectionChanged(object? sender, NotifyCollectionChangedEventArgs e)
         {
             base.LogicalChildrenCollectionChanged(sender, e);
-            VisualRoot?.Renderer.RecalculateChildren(this);
+            PresentationSource?.Renderer.RecalculateChildren(this);
         }
 
         /// <summary>
@@ -526,12 +528,8 @@ namespace Avalonia
         {
             Logger.TryGet(LogEventLevel.Verbose, LogArea.Visual)?.Log(this, "Attached to visual tree");
 
-            _visualRoot = e.Root;
+            PresentationSource = e.PresentationSource;
             RootedVisualChildrenCount++;
-            if (_visualParent is null)
-            {
-                throw new InvalidOperationException("Visual was attached to the root without being added to the visual parent first.");
-            }
 
             if (RenderTransform is IMutableTransform mutableTransform)
             {
@@ -539,27 +537,30 @@ namespace Avalonia
             }
 
             EnableTransitions();
-            if (_visualRoot.Renderer is IRendererWithCompositor compositingRenderer)
+            if (PresentationSource.Renderer is IRendererWithCompositor compositingRenderer)
             {
                 AttachToCompositor(compositingRenderer.Compositor);
             }
             InvalidateMirrorTransform();
-            UpdateIsEffectivelyVisible(_visualParent.IsEffectivelyVisible);
+            UpdateIsEffectivelyVisible(_visualParent?.IsEffectivelyVisible ?? true);
             OnAttachedToVisualTree(e);
             AttachedToVisualTree?.Invoke(this, e);
             InvalidateVisual();
 
-            _visualRoot.Renderer.RecalculateChildren(_visualParent);
+            if (_visualParent != null)
+            {
+                PresentationSource.Renderer.RecalculateChildren(_visualParent);
 
-            if (ZIndex != 0)
-                _visualParent.HasNonUniformZIndexChildren = true;
+                if (ZIndex != 0)
+                    _visualParent.HasNonUniformZIndexChildren = true;
+            }
 
             var visualChildren = VisualChildren;
             var visualChildrenCount = visualChildren.Count;
 
             for (var i = 0; i < visualChildrenCount; i++)
             {
-                if (visualChildren[i] is { } child && child._visualRoot != e.Root) // child may already have been attached within an event handler
+                if (visualChildren[i] is { } child && child.PresentationSource != e.PresentationSource) // child may already have been attached within an event handler
                 {
                     child.OnAttachedToVisualTreeCore(e);
                 }
@@ -575,7 +576,6 @@ namespace Avalonia
         {
             Logger.TryGet(LogEventLevel.Verbose, LogArea.Visual)?.Log(this, "Detached from visual tree");
             
-            _visualRoot = this as IRenderRoot;
             RootedVisualChildrenCount--;
 
             if (RenderTransform is IMutableTransform mutableTransform)
@@ -589,7 +589,9 @@ namespace Avalonia
             DetachFromCompositor();
 
             DetachedFromVisualTree?.Invoke(this, e);
-            e.Root.Renderer.AddDirty(this);
+            PresentationSource?.Renderer.AddDirty(this);
+            
+            PresentationSource = null;
 
             var visualChildren = VisualChildren;
             var visualChildrenCount = visualChildren.Count;
@@ -686,7 +688,7 @@ namespace Avalonia
                 parentVisual.HasNonUniformZIndexChildren = true;
 
             sender?.InvalidateVisual();
-            parent?.VisualRoot?.Renderer.RecalculateChildren(parent);
+            parent?.PresentationSource?.Renderer.RecalculateChildren(parent);
         }
 
         /// <summary>
@@ -714,17 +716,15 @@ namespace Avalonia
             var old = _visualParent;
             _visualParent = value;
 
-            if (_visualRoot is not null && old is not null)
+            if (PresentationSource is not null && old is not null)
             {
-                var e = new VisualTreeAttachmentEventArgs(old, _visualRoot);
+                var e = new VisualTreeAttachmentEventArgs(old, PresentationSource);
                 OnDetachedFromVisualTreeCore(e);
             }
 
-            if (_visualParent is IRenderRoot || _visualParent?.IsAttachedToVisualTree == true)
+            if (_visualParent?.IsAttachedToVisualTree == true)
             {
-                var root = this.FindAncestorOfType<IRenderRoot>() ??
-                    throw new AvaloniaInternalException("Visual is atached to visual tree but root could not be found.");
-                var e = new VisualTreeAttachmentEventArgs(_visualParent, root);
+                var e = new VisualTreeAttachmentEventArgs(_visualParent, _visualParent.PresentationSource!);
                 OnAttachedToVisualTreeCore(e);
             }
 
@@ -810,5 +810,26 @@ namespace Avalonia
 
             HasMirrorTransform = shouldApplyMirrorTransform;
         }
+
+        internal void SetPresentationSourceForRootVisual(IPresentationSource? presentationSource)
+        {
+            if(presentationSource == PresentationSource)
+                return;
+            
+            if (PresentationSource != null)
+            {
+                if (presentationSource != null)
+                    throw new InvalidOperationException(
+                        "Visual is already attached to a presentation source. Only one presentation source can be attached to a visual tree.");
+                OnDetachedFromVisualTreeCore(new(null, PresentationSource));
+            }
+
+            PresentationSource = presentationSource;
+            if(PresentationSource != null)
+            {
+                var e = new VisualTreeAttachmentEventArgs(null, PresentationSource);
+                OnAttachedToVisualTreeCore(e);
+            }
+        }
     }
 }

src/Avalonia.Base/VisualExtensions.cs

@@ -16,10 +16,11 @@ namespace Avalonia
         /// <returns>The point in client coordinates.</returns>
         public static Point PointToClient(this Visual visual, PixelPoint point)
         {
-            var root = visual.VisualRoot ??
-                 throw new ArgumentException("Control does not belong to a visual tree.", nameof(visual));
-            var rootPoint = root.PointToClient(point);
-            return ((Visual)root).TranslatePoint(rootPoint, visual)!.Value;
+            var source = visual.PresentationSource;
+            var root = source?.RootVisual ??
+                       throw new ArgumentException("Control does not belong to a visual tree.", nameof(visual));
+            var rootPoint = source.PointToClient(point);
+            return root.TranslatePoint(rootPoint, visual)!.Value;
         }
 
         /// <summary>
@@ -30,10 +31,11 @@ namespace Avalonia
         /// <returns>The point in screen coordinates.</returns>
         public static PixelPoint PointToScreen(this Visual visual, Point point)
         {
-            var root = visual.VisualRoot ??
-                throw new ArgumentException("Control does not belong to a visual tree.", nameof(visual));
-            var p = visual.TranslatePoint(point, (Visual)root);
-            return root.PointToScreen(p!.Value);
+            var source = visual.PresentationSource;
+            var root = source?.RootVisual ??
+                       throw new ArgumentException("Control does not belong to a visual tree.", nameof(visual));
+            var p = visual.TranslatePoint(point, root);
+            return source.PointToScreen(p!.Value);
         }
 
         /// <summary>

src/Avalonia.Base/VisualTree/VisualExtensions.cs

@@ -3,6 +3,8 @@ 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;
 
@@ -331,9 +333,10 @@ namespace Avalonia.VisualTree
         {
             ThrowHelper.ThrowIfNull(visual, nameof(visual));
 
-            var root = visual.GetVisualRoot();
+            var source = visual.GetPresentationSource();
+            var root = source?.RootVisual;
 
-            if (root is null)
+            if (source is null || root is null)
             {
                 return null;
             }
@@ -342,7 +345,7 @@ namespace Avalonia.VisualTree
 
             if (rootPoint.HasValue)
             {
-                return root.HitTester.HitTestFirst(rootPoint.Value, visual, filter);
+                return source.HitTester.HitTestFirst(rootPoint.Value, visual, filter);
             }
 
             return null;
@@ -380,14 +383,14 @@ namespace Avalonia.VisualTree
         {
             ThrowHelper.ThrowIfNull(visual, nameof(visual));
 
-            var root = visual.GetVisualRoot();
+            var source = visual.GetPresentationSource();
 
-            if (root is null)
+            if (source is null)
             {
                 return Array.Empty<Visual>();
             }
 
-            return root.HitTester.HitTest(p, visual, filter);
+            return source.HitTester.HitTest(p, visual, filter);
         }
 
         /// <summary>
@@ -456,19 +459,26 @@ namespace Avalonia.VisualTree
             return visual.VisualParent as T;
         }
 
+
+        public static IPresentationSource? GetPresentationSource(this Visual visual) => visual.PresentationSource;
+
+        // 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 root visual for an <see cref="Visual"/>.
+        /// Gets the layout manager for the visual's presentation source, or null if the visual is not attached to a visual root.
         /// </summary>
-        /// <param name="visual">The visual.</param>
-        /// <returns>
-        /// The root visual or null if the visual is not rooted.
-        /// </returns>
-        public static IRenderRoot? GetVisualRoot(this Visual visual)
-        {
-            ThrowHelper.ThrowIfNull(visual, nameof(visual));
+        public static ILayoutManager? GetLayoutManager(this Visual visual) =>
+            visual.PresentationSource?.LayoutRoot.LayoutManager;
 
-            return visual as IRenderRoot ?? visual.VisualRoot;
-        }
+        /// <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.
+        /// </summary>
+        public static IPlatformSettings? GetPlatformSettings(this Visual visual) =>
+            visual.GetPresentationSource()?.PlatformSettings;
 
         /// <summary>
         /// Returns a value indicating whether this control is attached to a visual root.

src/Avalonia.Base/VisualTreeAttachmentEventArgs.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Diagnostics;
 using Avalonia.Rendering;
 
 namespace Avalonia
@@ -12,22 +13,37 @@ namespace Avalonia
         /// <summary>
         /// Initializes a new instance of the <see cref="VisualTreeAttachmentEventArgs"/> class.
         /// </summary>
-        /// <param name="parent">The parent that the visual is being attached to or detached from.</param>
-        /// <param name="root">The root visual.</param>
-        public VisualTreeAttachmentEventArgs(Visual parent, IRenderRoot root)
+        /// <param name="attachmentPoint">The parent that the visual's tree is being attached to or detached from.</param>
+        /// <param name="presentationSource">Presentation source this visual is being attached to.</param>
+        public VisualTreeAttachmentEventArgs(Visual? attachmentPoint, IPresentationSource presentationSource)
         {
-            Parent = parent ?? throw new ArgumentNullException(nameof(parent));
-            Root = root ?? throw new ArgumentNullException(nameof(root));
+            RootVisual = presentationSource.RootVisual ??
+                         throw new InvalidOperationException("PresentationSource must have a non-null RootVisual.");
+            AttachmentPoint = attachmentPoint;
+            PresentationSource = presentationSource ?? throw new ArgumentNullException(nameof(presentationSource));
         }
 
         /// <summary>
-        /// Gets the parent that the visual is being attached to or detached from.
+        /// Gets the parent that the visual's tree is being attached to or detached from, null means that
+        /// the entire tree is being attached to a PresentationSource
         /// </summary>
-        public Visual Parent { get; }
+        public Visual? AttachmentPoint { get; }
+
+        [Obsolete("Use " + nameof(AttachmentPoint))]
+        public Visual? Parent => AttachmentPoint;
 
         /// <summary>
         /// Gets the root of the visual tree that the visual is being attached to or detached from.
         /// </summary>
-        public IRenderRoot Root { get; }
+        public IPresentationSource PresentationSource { get; }
+
+        [Obsolete("This was previously always returning TopLevel. This is no longer guaranteed. Use TopLevel.GetTopLevel(this) if you need a TopLevel or args.RootVisual if you are interested in the root of the visual tree.")]
+        public Visual Root => RootVisual;
+        
+        /// <summary>
+        /// The root visual of the tree this visual is being attached to or detached from.
+        /// This is guaranteed to be non-null and will be the same as <see cref="IPresentationSource.RootVisual"/>.
+        /// </summary>
+        public Visual RootVisual { get; set; }
     }
 }

src/Avalonia.Controls/Button.cs

@@ -208,14 +208,14 @@ namespace Avalonia.Controls
 
             if (IsDefault)
             {
-                if (e.Root is IInputElement inputElement)
+                if (e.RootVisual is IInputElement inputElement)
                 {
                     ListenForDefault(inputElement);
                 }
             }
             if (IsCancel)
             {
-                if (e.Root is IInputElement inputElement)
+                if (e.RootVisual is IInputElement inputElement)
                 {
                     ListenForCancel(inputElement);
                 }
@@ -229,14 +229,14 @@ namespace Avalonia.Controls
 
             if (IsDefault)
             {
-                if (e.Root is IInputElement inputElement)
+                if (e.RootVisual is IInputElement inputElement)
                 {
                     StopListeningForDefault(inputElement);
                 }
             }
             if (IsCancel)
             {
-                if (e.Root is IInputElement inputElement)
+                if (e.RootVisual is IInputElement inputElement)
                 {
                     StopListeningForCancel(inputElement);
                 }

src/Avalonia.Controls/Chrome/TitleBar.cs

@@ -54,7 +54,7 @@ namespace Avalonia.Controls.Chrome
 
             _captionButtons = e.NameScope.Get<CaptionButtons>("PART_CaptionButtons");
 
-            if (VisualRoot is Window window)
+            if (TopLevel.GetTopLevel(this) is Window window)
             {
                 _captionButtons?.Attach(window);
 
@@ -67,7 +67,7 @@ namespace Avalonia.Controls.Chrome
         {
             base.OnAttachedToVisualTree(e);
 
-            if (VisualRoot is Window window)
+            if (TopLevel.GetTopLevel(this) is Window window)
             {
                 _disposables = new CompositeDisposable(6)
                 {

src/Avalonia.Controls/Control.cs

@@ -509,7 +509,7 @@ namespace Avalonia.Controls
             if (e.Source == this
                 && !e.Handled)
             {
-                var keymap = TopLevel.GetTopLevel(this)?.PlatformSettings?.HotkeyConfiguration.OpenContextMenu;
+                var keymap = this.GetPlatformSettings()?.HotkeyConfiguration.OpenContextMenu;
 
                 if (keymap is null)
                 {

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/ExperimentalAcrylicBorder.cs

@@ -16,8 +16,8 @@ namespace Avalonia.Controls
         public static readonly StyledProperty<CornerRadius> CornerRadiusProperty =
             Border.CornerRadiusProperty.AddOwner<ExperimentalAcrylicBorder>();
 
-        public static readonly StyledProperty<ExperimentalAcrylicMaterial> MaterialProperty =
-            AvaloniaProperty.Register<ExperimentalAcrylicBorder, ExperimentalAcrylicMaterial>(nameof(Material));
+        public static readonly StyledProperty<ExperimentalAcrylicMaterial?> MaterialProperty =
+            AvaloniaProperty.Register<ExperimentalAcrylicBorder, ExperimentalAcrylicMaterial?>(nameof(Material));
 
         private IDisposable? _subscription;
         private IDisposable? _materialSubscription;
@@ -39,7 +39,7 @@ namespace Avalonia.Controls
             set => SetValue(CornerRadiusProperty, value);
         }
 
-        public ExperimentalAcrylicMaterial Material
+        public ExperimentalAcrylicMaterial? Material
         {
             get => GetValue(MaterialProperty);
             set => SetValue(MaterialProperty, value);
@@ -49,20 +49,29 @@ namespace Avalonia.Controls
         {
             base.OnAttachedToVisualTree(e);
 
-            var tl = (TopLevel)e.Root;
-
-            _subscription = tl.GetObservable(TopLevel.ActualTransparencyLevelProperty)
-                .Subscribe(x =>
-                {
-                    if (tl.PlatformImpl is null)
-                        return;
-                    if (x == WindowTransparencyLevel.Transparent || x == WindowTransparencyLevel.None)
-                        Material.PlatformTransparencyCompensationLevel = tl.PlatformImpl.AcrylicCompensationLevels.TransparentLevel;
-                    else if (x == WindowTransparencyLevel.Blur)
-                        Material.PlatformTransparencyCompensationLevel = tl.PlatformImpl.AcrylicCompensationLevels.BlurLevel;
-                    else if (x == WindowTransparencyLevel.AcrylicBlur)
-                        Material.PlatformTransparencyCompensationLevel = tl.PlatformImpl.AcrylicCompensationLevels.AcrylicBlurLevel;
-                });
+            var tl = TopLevel.GetTopLevel(this);
+            if (tl != null)
+            {
+
+                _subscription = tl.GetObservable(TopLevel.ActualTransparencyLevelProperty)
+                    .Subscribe(x =>
+                    {
+                        if (tl.PlatformImpl is null || Material is null)
+                            return;
+                        if (x == WindowTransparencyLevel.Transparent || x == WindowTransparencyLevel.None)
+                            Material.PlatformTransparencyCompensationLevel =
+                                tl.PlatformImpl.AcrylicCompensationLevels.TransparentLevel;
+                        else if (x == WindowTransparencyLevel.Blur)
+                            Material.PlatformTransparencyCompensationLevel =
+                                tl.PlatformImpl.AcrylicCompensationLevels.BlurLevel;
+                        else if (x == WindowTransparencyLevel.AcrylicBlur)
+                            Material.PlatformTransparencyCompensationLevel =
+                                tl.PlatformImpl.AcrylicCompensationLevels.AcrylicBlurLevel;
+                    });
+            }
+            else if (Material != null)
+                Material.PlatformTransparencyCompensationLevel = 1;
+
             UpdateMaterialSubscription();
         }
 
@@ -86,7 +95,9 @@ namespace Avalonia.Controls
             if (visual is CompositionExperimentalAcrylicVisual v)
             {
                 v.CornerRadius = CornerRadius;
-                v.Material = (ImmutableExperimentalAcrylicMaterial)Material.ToImmutable();
+                v.Material = (Material?.ToImmutable()) is ImmutableExperimentalAcrylicMaterial material
+                    ? material
+                    : default(ImmutableExperimentalAcrylicMaterial);
             }
         }
         

src/Avalonia.Controls/Flyouts/PopupFlyoutBase.cs

@@ -344,7 +344,7 @@ namespace Avalonia.Controls.Primitives
                     return;
                 }
 
-                if (Popup?.Host is PopupRoot && pArgs.Root is Visual eventRoot)
+                if (Popup?.Host is PopupRoot && pArgs.Root.RootElement is {} eventRoot)
                 {
                     // As long as the pointer stays within the enlargedPopupRect
                     // the flyout stays open. If it leaves, close it

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/IMenu.cs

@@ -23,6 +23,6 @@ namespace Avalonia.Controls
         /// <summary>
         /// Gets the root of the visual tree, if the control is attached to a visual tree.
         /// </summary>
-        IRenderRoot? VisualRoot { get; }
+        TopLevel? TopLevel { get; }
     }
 }

src/Avalonia.Controls/ListBox.cs

@@ -128,7 +128,7 @@ namespace Avalonia.Controls
 
         protected override void OnKeyDown(KeyEventArgs e)
         {
-            var hotkeys = Application.Current!.PlatformSettings?.HotkeyConfiguration;
+            var hotkeys = this.GetPlatformSettings()?.HotkeyConfiguration;
             var ctrl = hotkeys is not null && e.KeyModifiers.HasAllFlags(hotkeys.CommandModifiers);
 
             if (!ctrl &&

src/Avalonia.Controls/MaskedTextBox.cs

@@ -6,6 +6,7 @@ using System.Linq;
 using Avalonia.Input;
 using Avalonia.Input.Platform;
 using Avalonia.Interactivity;
+using Avalonia.VisualTree;
 
 namespace Avalonia.Controls
 {
@@ -203,7 +204,7 @@ namespace Avalonia.Controls
                 return;
             }
 
-            var keymap = Application.Current!.PlatformSettings?.HotkeyConfiguration;
+            var keymap = this.GetPlatformSettings()?.HotkeyConfiguration;
 
             bool Match(List<KeyGesture> gestures) => gestures.Any(g => g.Matches(e));
 

src/Avalonia.Controls/Menu.cs

@@ -88,7 +88,7 @@ namespace Avalonia.Controls
         {
             base.OnAttachedToVisualTree(e);
 
-            var inputRoot = e.Root as TopLevel;
+            var inputRoot = TopLevel.GetTopLevel(this);
 
             if (inputRoot?.AccessKeyHandler != null)
             {

src/Avalonia.Controls/MenuBase.cs

@@ -75,7 +75,7 @@ namespace Avalonia.Controls
         /// <inheritdoc/>
         IMenuInteractionHandler IMenu.InteractionHandler => InteractionHandler;
 
-        IRenderRoot? IMenu.VisualRoot => VisualRoot;
+        TopLevel? IMenu.TopLevel => TopLevel.GetTopLevel(this);
         
         /// <inheritdoc/>
         IMenuItem? IMenuElement.SelectedItem

src/Avalonia.Controls/MenuItemAccessKeyHandler.cs

@@ -9,7 +9,7 @@ namespace Avalonia.Controls
     /// </summary>
     internal class MenuItemAccessKeyHandler : AccessKeyHandler
     {
-        protected override void OnSetOwner(IInputRoot owner)
+        protected override void OnSetOwner(InputElement owner)
         {
             owner.AddHandler(InputElement.TextInputEvent, OnTextInput);
         }

src/Avalonia.Controls/NativeControlHost.cs

@@ -5,6 +5,7 @@ using Avalonia.Automation.Peers;
 using Avalonia.Controls.Automation.Peers;
 using Avalonia.Controls.Platform;
 using Avalonia.Platform;
+using Avalonia.Rendering;
 using Avalonia.Threading;
 using Avalonia.VisualTree;
 
@@ -12,7 +13,7 @@ namespace Avalonia.Controls
 {
     public class NativeControlHost : Control
     {
-        private TopLevel? _currentRoot;
+        private PresentationSource? _currentRoot;
         private INativeControlHostImpl? _currentHost;
         private INativeControlHostControlTopLevelAttachment? _attachment;
         private IPlatformHandle? _nativeControlHandle;
@@ -43,7 +44,7 @@ namespace Avalonia.Controls
         /// <inheritdoc />
         protected override void OnAttachedToVisualTree(VisualTreeAttachmentEventArgs e)
         {
-            _currentRoot = e.Root as TopLevel;
+            _currentRoot = (PresentationSource)e.PresentationSource;
             var visual = (Visual)this;
             while (visual != null)
             {
@@ -147,7 +148,7 @@ namespace Avalonia.Controls
 
             var bounds = Bounds;
             // Native window is not rendered by Avalonia
-            var transformToVisual = this.TransformToVisual(_currentRoot);
+            var transformToVisual = _currentRoot.RootVisual != null ? this.TransformToVisual(_currentRoot.RootVisual) : null;
             if (transformToVisual == null)
                 return null;
             var position = new Rect(default, bounds.Size).TransformToAABB(transformToVisual.Value).Position;

src/Avalonia.Controls/NativeMenuBar.cs

@@ -34,7 +34,7 @@ namespace Avalonia.Controls
                     ?? this.FindDescendantOfType<MenuBase>()
                     ?? throw new InvalidOperationException("NativeMenuBar requires a MenuBase#PART_NativeMenuPresenter template part.");
             
-            if (VisualRoot is TopLevel topLevel)
+            if (TopLevel.GetTopLevel(this) is {} topLevel)
             {
                 SubscribeToToplevel(topLevel, _menu);
             }
@@ -47,7 +47,7 @@ namespace Avalonia.Controls
             if (_menu is null)
                 return;
 
-            if (e.Root is TopLevel topLevel)
+            if (TopLevel.GetTopLevel(this) is {} topLevel)
             {
                 SubscribeToToplevel(topLevel, _menu);
             }

src/Avalonia.Controls/Platform/DefaultMenuInteractionHandler.cs

@@ -21,7 +21,7 @@ namespace Avalonia.Controls.Platform
     {
         private readonly bool _isContextMenu;
         private IDisposable? _inputManagerSubscription;
-        private IRenderRoot? _root;
+        private TopLevel? _root;
         private RadioButtonGroupManager? _groupManager;
 
         public DefaultMenuInteractionHandler(bool isContextMenu)
@@ -300,7 +300,7 @@ namespace Avalonia.Controls.Platform
             Menu.AddHandler(MenuItem.PointerExitedItemEvent, PointerExited);
             Menu.AddHandler(InputElement.PointerMovedEvent, PointerMoved);
 
-            _root = Menu.VisualRoot;
+            _root = Menu.TopLevel;
 
             if (_root is not null)
             {

src/Avalonia.Controls/Platform/InProcessDragSource.cs

@@ -19,7 +19,7 @@ namespace Avalonia.Platform
 
         private DragDropEffects _allowedEffects;
         private IDataTransfer? _draggedData;
-        private TopLevel? _lastRoot;
+        private PresentationSource? _lastSource;
         private Point _lastPosition;
         private StandardCursorType? _lastCursorType;
         private RawInputModifiers? _initialInputModifiers;
@@ -40,7 +40,7 @@ namespace Avalonia.Platform
             if (_draggedData == null)
             {
                 _draggedData = dataTransfer;
-                _lastRoot = null;
+                _lastSource = null;
                 _lastPosition = default;
                 _allowedEffects = allowedEffects;
 
@@ -75,11 +75,12 @@ namespace Avalonia.Platform
             _lastPosition = pt;
 
             RawDragEvent rawEvent = new RawDragEvent(_dragDrop, type, root, pt, _draggedData!, _allowedEffects, modifiers);
-            var tl = (root as Visual)?.GetSelfAndVisualAncestors().OfType<TopLevel>().FirstOrDefault();
-            tl?.PlatformImpl?.Input?.Invoke(rawEvent);
+            var source = root.RootElement.PresentationSource as PresentationSource;
+            
+            source?.PlatformImpl?.Input?.Invoke(rawEvent);
 
             var effect = GetPreferredEffect(rawEvent.Effects & _allowedEffects, modifiers);
-            UpdateCursor(tl, effect);
+            UpdateCursor(source, effect);
             return effect;
         }
 
@@ -105,12 +106,12 @@ namespace Avalonia.Platform
             return StandardCursorType.No;
         }
         
-        private void UpdateCursor(TopLevel? root, DragDropEffects effect)
+        private void UpdateCursor(PresentationSource? root, DragDropEffects effect)
         {
-            if (_lastRoot != root)
+            if (_lastSource != root)
             {
-                _lastRoot?.SetCursorOverride(null);
-                _lastRoot = root;
+                _lastSource?.SetCursorOverride(null);
+                _lastSource = root;
                 _lastCursorType = null;
             }
 
@@ -127,8 +128,8 @@ namespace Avalonia.Platform
 
         private void CancelDragging()
         {
-            if (_lastRoot != null)
-                RaiseEventAndUpdateCursor(RawDragEventType.DragLeave, _lastRoot, _lastPosition, RawInputModifiers.None);
+            if (_lastSource != null)
+                RaiseEventAndUpdateCursor(RawDragEventType.DragLeave, _lastSource, _lastPosition, RawInputModifiers.None);
             UpdateCursor(null, DragDropEffects.None);
             _result.OnNext(DragDropEffects.None);
         }
@@ -137,16 +138,16 @@ namespace Avalonia.Platform
         {
             if (e.Type == RawKeyEventType.KeyDown && e.Key == Key.Escape)
             {
-                if (_lastRoot != null)
-                    RaiseEventAndUpdateCursor(RawDragEventType.DragLeave, _lastRoot, _lastPosition, e.Modifiers);
+                if (_lastSource != null)
+                    RaiseEventAndUpdateCursor(RawDragEventType.DragLeave, _lastSource, _lastPosition, e.Modifiers);
                 UpdateCursor(null, DragDropEffects.None);
                 _result.OnNext(DragDropEffects.None);
                 e.Handled = true;
             }
             else if (e.Key == Key.LeftCtrl || e.Key == Key.RightCtrl || e.Key == Key.LeftAlt || e.Key == Key.RightAlt)
             {
-                if (_lastRoot != null)
-                    RaiseEventAndUpdateCursor(RawDragEventType.DragOver, _lastRoot, _lastPosition, e.Modifiers);
+                if (_lastSource != null)
+                    RaiseEventAndUpdateCursor(RawDragEventType.DragOver, _lastSource, _lastPosition, e.Modifiers);
             }
         }
 
@@ -195,10 +196,10 @@ namespace Avalonia.Platform
                         return;
                     }
 
-                    if (e.Root != _lastRoot)
+                    if (e.Root != _lastSource)
                     {
-                        if (_lastRoot is Visual lr && e.Root is Visual r)
-                            RaiseEventAndUpdateCursor(RawDragEventType.DragLeave, _lastRoot, lr.PointToClient(r.PointToScreen(e.Position)), e.InputModifiers);
+                        if (_lastSource?.RootElement is Visual lr && e.Root.RootElement is Visual r)
+                            RaiseEventAndUpdateCursor(RawDragEventType.DragLeave, _lastSource, lr.PointToClient(r.PointToScreen(e.Position)), e.InputModifiers);
                         RaiseEventAndUpdateCursor(RawDragEventType.DragEnter, e.Root, e.Position, e.InputModifiers);
                     }
                     else

src/Avalonia.Controls/PresentationSource/PresentationSource.Cursor.cs

@@ -0,0 +1,46 @@
+using Avalonia.Input;
+
+namespace Avalonia.Controls;
+
+internal partial class PresentationSource
+{
+    private Cursor? _cursor;
+    private Cursor? _cursorOverride;
+
+    private void UpdateCursor() => PlatformImpl?.SetCursor(_cursorOverride?.PlatformImpl ?? _cursor?.PlatformImpl);
+
+    private void SetCursor(Cursor? cursor)
+    {
+        _cursor = cursor;
+        UpdateCursor();
+    }
+    
+    /// <summary>
+    /// This should only be used by InProcessDragSource
+    /// </summary>
+    internal void SetCursorOverride(Cursor? cursor)
+    {
+        _cursorOverride = cursor;
+        UpdateCursor();
+    }
+    
+    IInputElement? IInputRoot.PointerOverElement
+    {
+        get => field;
+        set
+        {
+            if (field is AvaloniaObject old)
+                old.PropertyChanged -= PointerOverElement_PropertyChanged;
+            field = value;
+            if (field is AvaloniaObject @new)
+                @new.PropertyChanged += PointerOverElement_PropertyChanged;
+            SetCursor(value?.Cursor);
+        }
+    }
+
+    private void PointerOverElement_PropertyChanged(object? sender, AvaloniaPropertyChangedEventArgs e)
+    {
+        if (e.Property == InputElement.CursorProperty)
+            SetCursor((sender as IInputElement)?.Cursor);
+    }
+}

src/Avalonia.Controls/PresentationSource/PresentationSource.Input.cs

@@ -0,0 +1,60 @@
+using System;
+using System.Threading;
+using Avalonia.Diagnostics;
+using Avalonia.Input;
+using Avalonia.Input.Raw;
+using Avalonia.Logging;
+using Avalonia.Platform;
+using Avalonia.Threading;
+
+namespace Avalonia.Controls;
+
+internal partial class PresentationSource
+{
+    public IInputRoot InputRoot => this;
+    
+    /// <summary>
+    /// Handles input from <see cref="ITopLevelImpl.Input"/>.
+    /// </summary>
+    private void HandleInputCore(object? state)
+    {
+        using var _ = Diagnostic.BeginLayoutInputPass();
+
+        var e = (RawInputEventArgs)state!;
+        if (e is RawPointerEventArgs pointerArgs)
+        {
+            var hitTestElement = RootElement.InputHitTest(pointerArgs.Position, enabledElementsOnly: false);
+
+            pointerArgs.InputHitTestResult = (hitTestElement, FirstEnabledAncestor(hitTestElement));
+        }
+
+        _inputManager?.ProcessInput(e);
+    }
+
+    private SendOrPostCallback _handleInputCore;
+    
+    private void HandleInput(RawInputEventArgs e)
+    {
+        if (PlatformImpl != null)
+        {
+            Dispatcher.UIThread.Send(_handleInputCore, e);
+        }
+        else
+        {
+            Logger.TryGet(LogEventLevel.Warning, LogArea.Control)?.Log(
+                this,
+                "PlatformImpl is null, couldn't handle input.");
+        }
+    }
+    
+    
+    private static IInputElement? FirstEnabledAncestor(IInputElement? hitTestElement)
+    {
+        var candidate = hitTestElement;
+        while (candidate?.IsEffectivelyEnabled == false)
+        {
+            candidate = (candidate as Visual)?.VisualParent as IInputElement;
+        }
+        return candidate;
+    }
+}

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.RenderRoot.cs

@@ -0,0 +1,29 @@
+using System;
+using Avalonia.Input;
+using Avalonia.Rendering;
+using Avalonia.Rendering.Composition;
+
+namespace Avalonia.Controls;
+
+internal partial class PresentationSource
+{
+    private readonly Func<Size> _clientSizeProvider;
+    public CompositingRenderer Renderer { get; }
+    IRenderer IPresentationSource.Renderer => Renderer;
+    Visual IPresentationSource.RootVisual => RootVisual;
+    public IHitTester HitTester => HitTesterOverride ?? Renderer;
+    //TODO: Can we PLEASE get rid of this abomination in tests and use actual hit-testing engine instead?
+    public IHitTester? HitTesterOverride { get; set; }
+    
+    public double RenderScaling => PlatformImpl?.RenderScaling ?? 1;
+    public Size ClientSize => _clientSizeProvider();
+    
+    public void SceneInvalidated(object? sender, SceneInvalidatedEventArgs sceneInvalidatedEventArgs)
+    {
+        _pointerOverPreProcessor?.SceneInvalidated(sceneInvalidatedEventArgs.DirtyRect);
+    }
+
+    public PixelPoint PointToScreen(Point point) => PlatformImpl?.PointToScreen(point) ?? default;
+
+    public Point PointToClient(PixelPoint point) => PlatformImpl?.PointToClient(point) ?? default;
+}

src/Avalonia.Controls/PresentationSource/PresentationSource.cs

@@ -0,0 +1,116 @@
+using System;
+using Avalonia.Input;
+using Avalonia.Input.TextInput;
+using Avalonia.Layout;
+using Avalonia.Logging;
+using Avalonia.Platform;
+using Avalonia.Rendering;
+using Avalonia.Rendering.Composition;
+
+namespace Avalonia.Controls;
+
+internal partial class PresentationSource : IPresentationSource, IInputRoot, IDisposable
+{
+    public ITopLevelImpl? PlatformImpl { get; private set; }
+    private readonly PointerOverPreProcessor? _pointerOverPreProcessor;
+    private readonly IDisposable? _pointerOverPreProcessorSubscription;
+    private readonly IInputManager? _inputManager;
+    
+
+    internal FocusManager FocusManager { get; } = new();
+
+    public PresentationSource(InputElement rootVisual, ITopLevelImpl platformImpl,
+        IAvaloniaDependencyResolver dependencyResolver, Func<Size> clientSizeProvider)
+    {
+        _clientSizeProvider = clientSizeProvider;
+
+        PlatformImpl = platformImpl;
+
+    
+        _inputManager = TryGetService<IInputManager>(dependencyResolver);
+        _handleInputCore = HandleInputCore;
+        
+        PlatformImpl.SetInputRoot(this);
+        PlatformImpl.Input = HandleInput;
+        
+        _pointerOverPreProcessor = new PointerOverPreProcessor(this);
+        _pointerOverPreProcessorSubscription = _inputManager?.PreProcess.Subscribe(_pointerOverPreProcessor);
+        
+        Renderer = new CompositingRenderer(this, PlatformImpl.Compositor, () => PlatformImpl.Surfaces ?? []);
+        Renderer.SceneInvalidated += SceneInvalidated;
+        LayoutManager = CreateLayoutManager();
+        
+        RootVisual = rootVisual;
+    }
+
+    // In WPF it's a Visual and it's nullable. For now we have it as non-nullable InputElement since 
+    // there are way too many things to update at once and the current goal is to decouple
+    // "visual tree root" concept from TopLevel
+    public InputElement RootVisual
+    {
+        get => field;
+        set
+        {
+            field?.SetPresentationSourceForRootVisual(null);
+            field = value;
+
+            field?.SetPresentationSourceForRootVisual(this);
+            Renderer.CompositionTarget.Root = field?.CompositionVisual;
+
+            FocusManager.SetContentRoot(value as IInputElement);
+        }
+    }
+
+
+    IFocusManager? IInputRoot.FocusManager => FocusManager;
+
+    IPlatformSettings? IPresentationSource.PlatformSettings => AvaloniaLocator.Current.GetService<IPlatformSettings>();
+    
+    ITextInputMethodImpl? IInputRoot.InputMethod => PlatformImpl?.TryGetFeature<ITextInputMethodImpl>();
+    public InputElement RootElement => RootVisual;
+
+
+    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();
+
+        PlatformImpl = null;
+        _pointerOverPreProcessor?.OnCompleted();
+        _pointerOverPreProcessorSubscription?.Dispose();
+        if (((IInputRoot)this).PointerOverElement is AvaloniaObject pointerOverElement)
+            pointerOverElement.PropertyChanged -= PointerOverElement_PropertyChanged;
+    }
+    
+    /// <summary>
+    /// Tries to get a service from an <see cref="IAvaloniaDependencyResolver"/>, logging a
+    /// warning if not found.
+    /// </summary>
+    /// <typeparam name="T">The service type.</typeparam>
+    /// <param name="resolver">The resolver.</param>
+    /// <returns>The service.</returns>
+    private T? TryGetService<T>(IAvaloniaDependencyResolver resolver) where T : class
+    {
+        var result = resolver.GetService<T>();
+
+        if (result == null)
+        {
+            Logger.TryGet(LogEventLevel.Warning, LogArea.Control)?.Log(
+                this,
+                "Could not create {Service} : maybe Application.RegisterServices() wasn't called?",
+                typeof(T));
+        }
+
+        return result;
+    }
+
+    // TODO: Make popup positioner to use PresentationSource internally rather than TopLevel
+    public PixelPoint? GetLastPointerPosition(Visual topLevel)
+    {
+        return _pointerOverPreProcessor?.LastPosition;
+    }
+}

src/Avalonia.Controls/Primitives/AccessText.cs

@@ -17,7 +17,7 @@ namespace Avalonia.Controls.Primitives
         /// Defines the <see cref="ShowAccessKey"/> attached property.
         /// </summary>
         public static readonly AttachedProperty<bool> ShowAccessKeyProperty =
-            AvaloniaProperty.RegisterAttached<AccessText, Control, bool>("ShowAccessKey", inherits: true);
+            AccessKeyHandler.ShowAccessKeyProperty.AddOwner<AccessText>();
 
         /// <summary>
         /// The access key handler for the current window.
@@ -92,7 +92,7 @@ namespace Avalonia.Controls.Primitives
         protected override void OnAttachedToVisualTree(VisualTreeAttachmentEventArgs e)
         {
             base.OnAttachedToVisualTree(e);
-            _accessKeys = (e.Root as TopLevel)?.AccessKeyHandler;
+            _accessKeys = TopLevel.GetTopLevel(this)?.AccessKeyHandler;
 
             if (_accessKeys != null && !string.IsNullOrEmpty(AccessKey))
             {

src/Avalonia.Controls/Primitives/ItemSelectionEventTriggers.cs

@@ -1,6 +1,7 @@
 using Avalonia.Input;
 using Avalonia.Input.Platform;
 using Avalonia.Interactivity;
+using Avalonia.VisualTree;
 
 namespace Avalonia.Controls.Primitives;
 
@@ -75,7 +76,7 @@ public static class ItemSelectionEventTriggers
     public static bool HasToggleSelectionModifier(Visual selectable, RoutedEventArgs eventArgs) => HasModifiers(eventArgs, Hotkeys(selectable)?.CommandModifiers);
 
     private static PlatformHotkeyConfiguration? Hotkeys(Visual element) =>
-        (TopLevel.GetTopLevel(element)?.PlatformSettings ?? Application.Current?.PlatformSettings)?.HotkeyConfiguration;
+        (element.GetPlatformSettings() ?? Application.Current?.PlatformSettings)?.HotkeyConfiguration;
 
     private static bool HasModifiers(RoutedEventArgs eventArgs, KeyModifiers? modifiers) =>
         modifiers != null && eventArgs is IKeyModifiersEventArgs { KeyModifiers: { } eventModifiers } && eventModifiers.HasAllFlags(modifiers.Value);

src/Avalonia.Controls/Primitives/OverlayPopupHost.cs

@@ -3,6 +3,7 @@ using System.Collections.Generic;
 using Avalonia.Controls.Primitives.PopupPositioning;
 using Avalonia.Diagnostics;
 using Avalonia.Input;
+using Avalonia.Input.TextInput;
 using Avalonia.Interactivity;
 using Avalonia.Media;
 using Avalonia.Metadata;
@@ -10,7 +11,7 @@ using Avalonia.Platform;
 
 namespace Avalonia.Controls.Primitives
 {
-    public class OverlayPopupHost : ContentControl, IPopupHost, IManagedPopupPositionerPopup, IInputRoot
+    public class OverlayPopupHost : ContentControl, IPopupHost, IManagedPopupPositionerPopup
     {
         /// <summary>
         /// Defines the <see cref="Transform"/> property.
@@ -21,6 +22,7 @@ namespace Avalonia.Controls.Primitives
         private readonly OverlayLayer _overlayLayer;
         private readonly ManagedPopupPositioner _positioner;
         private readonly IKeyboardNavigationHandler? _keyboardNavigationHandler;
+        internal IKeyboardNavigationHandler Tests_KeyboardNavigationHandler => _keyboardNavigationHandler!;
         private Point _lastRequestedPosition;
         private PopupPositionRequest? _popupPositionRequest;
         private Size _popupSize;
@@ -60,38 +62,6 @@ namespace Avalonia.Controls.Primitives
             set { /* Not currently supported in overlay popups */ }
         }
         
-        private IInputRoot? InputRoot
-            => TopLevel.GetTopLevel(this);
-
-        IKeyboardNavigationHandler? IInputRoot.KeyboardNavigationHandler
-            => _keyboardNavigationHandler;
-
-        IFocusManager? IInputRoot.FocusManager
-            => InputRoot?.FocusManager;
-
-        IPlatformSettings? IInputRoot.PlatformSettings
-            => InputRoot?.PlatformSettings;
-
-        IInputElement? IInputRoot.PointerOverElement
-        {
-            get => InputRoot?.PointerOverElement;
-            set
-            {
-                if (InputRoot is { } inputRoot)
-                    inputRoot.PointerOverElement = value;
-            }
-        }
-
-        bool IInputRoot.ShowAccessKeys
-        {
-            get => InputRoot?.ShowAccessKeys ?? false;
-            set
-            {
-                if (InputRoot is { } inputRoot)
-                    inputRoot.ShowAccessKeys = value;
-            }
-        }
-
         /// <inheritdoc />
         internal override Interactive? InteractiveParent => Parent as Interactive;
 

src/Avalonia.Controls/Primitives/Popup.cs

@@ -676,7 +676,7 @@ namespace Avalonia.Controls.Primitives
                     {
                         var newTarget = change.GetNewValue<Control?>() ?? this.FindLogicalAncestorOfType<Control>();
 
-                        if (newTarget is null || newTarget.GetVisualRoot() != _openState.TopLevel)
+                        if (newTarget is null || TopLevel.GetTopLevel(newTarget) != _openState.TopLevel)
                         {
                             Close();
                             return;

src/Avalonia.Controls/Primitives/PopupPositioning/IPopupPositioner.cs

@@ -574,7 +574,7 @@ namespace Avalonia.Controls.Primitives.PopupPositioning
             
             if (matrix == null)
             {
-                if (target.GetVisualRoot() == null)
+                if (!target.IsAttachedToVisualTree)
                     throw new InvalidOperationException("Target control is not attached to the visual tree");
                 throw new InvalidOperationException("Target control is not in the same tree as the popup parent");
             }

src/Avalonia.Controls/Primitives/PopupRoot.cs

@@ -2,6 +2,7 @@ using System;
 using Avalonia.Automation.Peers;
 using Avalonia.Controls.Primitives.PopupPositioning;
 using Avalonia.Diagnostics;
+using Avalonia.Input;
 using Avalonia.Interactivity;
 using Avalonia.Media;
 using Avalonia.Metadata;

src/Avalonia.Controls/RadioButton.cs

@@ -52,7 +52,7 @@ namespace Avalonia.Controls
         protected override void OnAttachedToVisualTree(VisualTreeAttachmentEventArgs e)
         {
             _groupManager?.Remove(this, GroupName);
-            EnsureRadioGroupManager(e.Root);
+            EnsureRadioGroupManager(e.PresentationSource);
             base.OnAttachedToVisualTree(e);
         }
 
@@ -106,9 +106,9 @@ namespace Avalonia.Controls
         }
         
         [MemberNotNull(nameof(_groupManager))]
-        private void EnsureRadioGroupManager(IRenderRoot? root = null)
+        private void EnsureRadioGroupManager(IPresentationSource? source = null)
         {
-            _groupManager = RadioButtonGroupManager.GetOrCreateForRoot(root ?? this.GetVisualRoot());
+            _groupManager = RadioButtonGroupManager.GetOrCreateForRoot(source ?? this.GetPresentationSource());
             _groupManager.Add(this);
         }
     }

src/Avalonia.Controls/RadioButtonGroupManager.cs

@@ -18,12 +18,12 @@ internal interface IRadioButton : ILogical
 internal class RadioButtonGroupManager
 {
     private static readonly RadioButtonGroupManager s_default = new();
-    private static readonly ConditionalWeakTable<IRenderRoot, RadioButtonGroupManager> s_registeredVisualRoots = new();
+    private static readonly ConditionalWeakTable<object, RadioButtonGroupManager> s_registeredVisualRoots = new();
 
     private readonly Dictionary<string, List<WeakReference<IRadioButton>>> _registeredGroups = new();
     private bool _ignoreCheckedChanges;
 
-    public static RadioButtonGroupManager GetOrCreateForRoot(IRenderRoot? root)
+    public static RadioButtonGroupManager GetOrCreateForRoot(object? root)
     {
         if (root == null)
             return s_default;

src/Avalonia.Controls/Remote/Server/RemoteServerTopLevelImpl.cs

@@ -265,7 +265,7 @@ namespace Avalonia.Controls.Remote.Server
 
         protected virtual Size Measure(Size constraint)
         {
-            var l = (Layoutable) InputRoot!;
+            var l = InputRoot!.RootElement;
             l.Measure(constraint);
             return l.DesiredSize;
         }

src/Avalonia.Controls/ToolTipService.cs

@@ -38,12 +38,12 @@ namespace Avalonia.Controls
             if (e is RawPointerEventArgs pointerEvent)
             {
                 bool isTooltipEvent = false;
-                if (_tipControl?.GetValue(ToolTip.ToolTipProperty) is { } currentTip && e.Root == currentTip.PopupHost)
+                if (_tipControl?.GetValue(ToolTip.ToolTipProperty) is { } currentTip && e.Root.RootElement == currentTip.PopupHost)
                 {
                     isTooltipEvent = true;
                     _lastTipEventTime = pointerEvent.Timestamp;
                 }
-                else if (e.Root == _tipControl?.VisualRoot)
+                else if (e.Root.RootElement == _tipControl?.VisualRoot)
                 {
                     _lastWindowEventTime = pointerEvent.Timestamp;
                 }
@@ -53,7 +53,7 @@ namespace Avalonia.Controls
                     case RawPointerEventType.Move:
                         Update(pointerEvent.Root, pointerEvent.InputHitTestResult.element as Visual);
                         break;
-                    case RawPointerEventType.LeaveWindow when (e.Root == _tipControl?.VisualRoot && _lastTipEventTime != e.Timestamp) || (isTooltipEvent && _lastWindowEventTime != e.Timestamp):
+                    case RawPointerEventType.LeaveWindow when (e.Root.RootElement == _tipControl?.VisualRoot && _lastTipEventTime != e.Timestamp) || (isTooltipEvent && _lastWindowEventTime != e.Timestamp):
                         ClearTip();
                         _tipControl = null;
                         break;

src/Avalonia.Controls/TopLevel.cs

@@ -39,13 +39,9 @@ namespace Avalonia.Controls
     /// </remarks>
     [TemplatePart("PART_TransparencyFallback", typeof(Border))]
     public abstract class TopLevel : ContentControl,
-        IInputRoot,
-        ILayoutRoot,
-        IRenderRoot,
         ICloseable,
         IStyleHost,
-        ILogicalRoot,
-        ITextInputMethodRoot
+        ILogicalRoot
     {
         /// <summary>
         /// Defines the <see cref="ClientSize"/> property.
@@ -59,12 +55,6 @@ namespace Avalonia.Controls
         public static readonly DirectProperty<TopLevel, Size?> FrameSizeProperty =
             AvaloniaProperty.RegisterDirect<TopLevel, Size?>(nameof(FrameSize), o => o.FrameSize);
 
-        /// <summary>
-        /// Defines the <see cref="IInputRoot.PointerOverElement"/> property.
-        /// </summary>
-        public static readonly StyledProperty<IInputElement?> PointerOverElementProperty =
-            AvaloniaProperty.Register<TopLevel, IInputElement?>(nameof(IInputRoot.PointerOverElement));
-
         /// <summary>
         /// Defines the <see cref="TransparencyLevelHint"/> property.
         /// </summary>
@@ -125,24 +115,22 @@ namespace Avalonia.Controls
         private readonly IToolTipService? _tooltipService;
         private readonly IAccessKeyHandler? _accessKeyHandler;
         private readonly IKeyboardNavigationHandler? _keyboardNavigationHandler;
+        internal IKeyboardNavigationHandler Tests_KeyboardNavigationHandler => _keyboardNavigationHandler!;
         private readonly IGlobalStyles? _globalStyles;
         private readonly IThemeVariantHost? _applicationThemeHost;
-        private readonly PointerOverPreProcessor? _pointerOverPreProcessor;
-        private readonly IDisposable? _pointerOverPreProcessorSubscription;
         private readonly IDisposable? _backGestureSubscription;
         private readonly Dictionary<AvaloniaProperty, Action> _platformImplBindings = new();
         private double _scaling;
         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 Cursor? _cursor;
-        private Cursor? _cursorOverride;
+        private readonly PresentationSource _source;
+        internal new PresentationSource PresentationSource => _source;
+        internal IInputRoot InputRoot => _source;
         
         /// <summary>
         /// Initializes static members of the <see cref="TopLevel"/> class.
@@ -176,19 +164,6 @@ namespace Avalonia.Controls
                 topLevel?.InvalidateChildInsetsPadding();
             });
 
-            PointerOverElementProperty.Changed.AddClassHandler<TopLevel>((topLevel, e) =>
-            {
-                if (e.OldValue is InputElement oldInputElement)
-                {
-                    oldInputElement.PropertyChanged -= topLevel.PointerOverElementOnPropertyChanged;
-                }
-
-                if (e.NewValue is InputElement newInputElement)
-                {
-                    topLevel.SetCursor(newInputElement.Cursor);
-                    newInputElement.PropertyChanged += topLevel.PointerOverElementOnPropertyChanged;
-                }
-            });
 
             ToolTip.ServiceEnabledProperty.Changed.Subscribe(OnToolTipServiceEnabledChanged);
         }
@@ -209,15 +184,20 @@ namespace Avalonia.Controls
         /// <param name="dependencyResolver">
         /// The dependency resolver to use. If null the default dependency resolver will be used.
         /// </param>
-        public TopLevel(ITopLevelImpl impl, IAvaloniaDependencyResolver? dependencyResolver)
+        internal TopLevel(ITopLevelImpl impl, IAvaloniaDependencyResolver? dependencyResolver)
         {
             PlatformImpl = impl ?? throw new InvalidOperationException(
                 "Could not create window implementation: maybe no windowing subsystem was initialized?");
+            dependencyResolver ??= AvaloniaLocator.Current;
+            _source = new PresentationSource(this, impl, dependencyResolver, () => ClientSize);
+            _source.RootVisual = this;
+            _source.Renderer.SceneInvalidated += SceneInvalidated;
 
             _scaling = ValidateScaling(impl.RenderScaling);
             _actualTransparencyLevel = PlatformImpl.TransparencyLevel;
             
-            dependencyResolver ??= AvaloniaLocator.Current;
+
+            
 
             _accessKeyHandler = TryGetService<IAccessKeyHandler>(dependencyResolver);
             _inputManager = TryGetService<IInputManager>(dependencyResolver);
@@ -226,13 +206,10 @@ namespace Avalonia.Controls
             _globalStyles = TryGetService<IGlobalStyles>(dependencyResolver);
             _applicationThemeHost = TryGetService<IThemeVariantHost>(dependencyResolver);
 
-            Renderer = new CompositingRenderer(this, impl.Compositor, () => PlatformImpl.Surfaces ?? []);
-            Renderer.SceneInvalidated += SceneInvalidated;
 
-            impl.SetInputRoot(this);
+            
 
             impl.Closed = HandleClosed;
-            impl.Input = HandleInput;
             impl.Paint = HandlePaint;
             impl.Resized = HandleResized;
             impl.ScalingChanged = HandleScalingChanged;
@@ -276,8 +253,7 @@ namespace Avalonia.Controls
 
             impl.LostFocus += PlatformImpl_LostFocus;
 
-            _pointerOverPreProcessor = new PointerOverPreProcessor(this);
-            _pointerOverPreProcessorSubscription = _inputManager?.PreProcess.Subscribe(_pointerOverPreProcessor);
+
 
             if(impl.TryGetFeature<ISystemNavigationManagerImpl>() is {} systemNavigationManager)
             {
@@ -407,26 +383,7 @@ 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.
@@ -461,24 +418,23 @@ namespace Avalonia.Controls
         /// <summary>
         /// Gets the renderer for the window.
         /// </summary>
-        internal CompositingRenderer Renderer { get; }
-
-        internal IHitTester HitTester => HitTesterOverride ?? Renderer;
+        internal CompositingRenderer Renderer => _source.Renderer;
 
         // This property setter is here purely for lazy unit tests
         // that don't want to set up a proper hit-testable visual tree
         // and should be removed after fixing those tests
-        internal IHitTester? HitTesterOverride;
-
-        IRenderer IRenderRoot.Renderer => Renderer;
-        IHitTester IRenderRoot.HitTester => HitTester;
+        internal IHitTester? HitTesterOverride
+        {
+            get => _source.HitTesterOverride;
+            set => _source.HitTesterOverride = value;
+        }
 
         /// <summary>
         /// Gets a value indicating whether the renderer should draw specific diagnostics.
         /// </summary>
         public RendererDiagnostics RendererDiagnostics => Renderer.Diagnostics;
 
-        internal PixelPoint? LastPointerPosition => _pointerOverPreProcessor?.LastPosition;
+        internal PixelPoint? LastPointerPosition => _source.GetLastPointerPosition(this);
         
         /// <summary>
         /// Gets the access key handler for the window.
@@ -488,23 +444,6 @@ namespace Avalonia.Controls
         /// <summary>
         /// Gets or sets the keyboard navigation handler for the window.
         /// </summary>
-        IKeyboardNavigationHandler? IInputRoot.KeyboardNavigationHandler => _keyboardNavigationHandler;
-
-        /// <inheritdoc/>
-        IInputElement? IInputRoot.PointerOverElement
-        {
-            get => GetValue(PointerOverElementProperty);
-            set => SetValue(PointerOverElementProperty, value);
-        }
-
-        /// <summary>
-        /// Gets or sets a value indicating whether access keys are shown in the window.
-        /// </summary>
-        bool IInputRoot.ShowAccessKeys
-        {
-            get => GetValue(AccessText.ShowAccessKeyProperty);
-            set => SetValue(AccessText.ShowAccessKeyProperty, value);
-        }
         
         /// <summary>
         /// Helper for setting the color of the platform's system bars.
@@ -545,8 +484,6 @@ namespace Avalonia.Controls
             return control.GetValue(AutoSafeAreaPaddingProperty);
         }
 
-        double ILayoutRoot.LayoutScaling => _scaling;
-
         /// <inheritdoc/>
         public double RenderScaling => _scaling;
 
@@ -575,23 +512,22 @@ namespace Avalonia.Controls
         /// </summary>
         public IClipboard? Clipboard => PlatformImpl?.TryGetFeature<IClipboard>();
 
-        /// <inheritdoc />
-        public IFocusManager? FocusManager => _focusManager ??= new FocusManager(this);
-
-        /// <inheritdoc />
-        public IPlatformSettings? PlatformSettings => AvaloniaLocator.Current.GetService<IPlatformSettings>();
-
-        /// <inheritdoc/>
-        Point IRenderRoot.PointToClient(PixelPoint p)
-        {
-            return PlatformImpl?.PointToClient(p) ?? default;
-        }
+        /// <summary>
+        /// Gets focus manager of the root.
+        /// </summary>
+        /// <remarks>
+        /// Focus manager can be null only if window wasn't initialized yet.
+        /// </remarks>
+        public IFocusManager FocusManager => _source.FocusManager;
 
-        /// <inheritdoc/>
-        PixelPoint IRenderRoot.PointToScreen(Point p)
-        {
-            return PlatformImpl?.PointToScreen(p) ?? default;
-        }
+        /// <summary>
+        /// Represents a contract for accessing top-level platform-specific settings.
+        /// </summary>
+        /// <remarks>
+        /// PlatformSettings can be null only if window wasn't initialized yet.
+        /// </remarks>
+        // TODO: Un-private
+        private IPlatformSettings? PlatformSettings => AvaloniaLocator.Current.GetService<IPlatformSettings>();
 
         /// <summary>
         /// Gets the <see cref="TopLevel" /> for which the given <see cref="Visual"/> is hosted in.
@@ -600,7 +536,14 @@ namespace Avalonia.Controls
         /// <returns>The TopLevel</returns>
         public static TopLevel? GetTopLevel(Visual? visual)
         {
-            return visual?.VisualRoot as TopLevel;
+            while (visual != null)
+            {
+                if (visual is TopLevel tl)
+                    return tl;
+                visual = visual.VisualParent;
+            }
+
+            return null;
         }
 
         /// <summary>
@@ -651,7 +594,6 @@ namespace Avalonia.Controls
         }
 
         private IDisposable? _insetsPaddings;
-        private FocusManager? _focusManager;
 
         private void InvalidateChildInsetsPadding()
         {
@@ -677,11 +619,6 @@ 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>
@@ -691,18 +628,16 @@ namespace Avalonia.Controls
             Renderer.Paint(rect);
         }
 
-        protected void StartRendering() => MediaContext.Instance.AddTopLevel(this, LayoutManager, Renderer);
+        private protected void StartRendering() => MediaContext.Instance.AddTopLevel(this, LayoutManager, Renderer);
 
-        protected void StopRendering() => MediaContext.Instance.RemoveTopLevel(this);
+        private protected void StopRendering() => MediaContext.Instance.RemoveTopLevel(this);
 
         /// <summary>
         /// Handles a closed notification from <see cref="ITopLevelImpl.Closed"/>.
         /// </summary>
         private protected virtual void HandleClosed()
         {
-            Renderer.SceneInvalidated -= SceneInvalidated;
-            // We need to wait for the renderer to complete any in-flight operations
-            Renderer.Dispose();
+            _source.Dispose();
             StopRendering();
             
             Debug.Assert(PlatformImpl != null);
@@ -720,18 +655,12 @@ namespace Avalonia.Controls
                 _applicationThemeHost.ActualThemeVariantChanged -= GlobalActualThemeVariantChanged;
             }
             
-            _layoutDiagnosticBridge?.Dispose();
-            _layoutDiagnosticBridge = null;
-
-            _pointerOverPreProcessor?.OnCompleted();
-            _pointerOverPreProcessorSubscription?.Dispose();
             _backGestureSubscription?.Dispose();
 
             var logicalArgs = new LogicalTreeAttachmentEventArgs(this, this, null);
             ((ILogical)this).NotifyDetachedFromLogicalTree(logicalArgs);
 
-            var visualArgs = new VisualTreeAttachmentEventArgs(this, this);
-            OnDetachedFromVisualTreeCore(visualArgs);
+            _source.RootVisual = null!;
             
             OnClosed(EventArgs.Empty);
 
@@ -784,15 +713,6 @@ namespace Avalonia.Controls
             ActualTransparencyLevel = transparencyLevel;
         }
 
-        /// <inheritdoc/>
-        protected override void OnAttachedToVisualTree(VisualTreeAttachmentEventArgs e)
-        {
-            base.OnAttachedToVisualTree(e);
-
-            throw new InvalidOperationException(
-                $"Control '{GetType().Name}' is a top level control and cannot be added as a child.");
-        }
-
         protected override void OnApplyTemplate(TemplateAppliedEventArgs e)
         {
             base.OnApplyTemplate(e);
@@ -844,73 +764,6 @@ namespace Avalonia.Controls
             return result;
         }
 
-        /// <summary>
-        /// Handles input from <see cref="ITopLevelImpl.Input"/>.
-        /// </summary>
-        /// <param name="e">The event args.</param>
-        private void HandleInput(RawInputEventArgs e)
-        {
-            if (PlatformImpl != null)
-            {
-                Dispatcher.UIThread.Send(static state =>
-                {
-                    using var _ = Diagnostic.BeginLayoutInputPass();
-
-                    var (topLevel, e) = (ValueTuple<TopLevel, RawInputEventArgs>)state!;
-                    if (e is RawPointerEventArgs pointerArgs)
-                    {
-                        var hitTestElement = topLevel.InputHitTest(pointerArgs.Position, enabledElementsOnly: false);
-
-                        pointerArgs.InputHitTestResult = (hitTestElement, FirstEnabledAncestor(hitTestElement));
-                    }
-
-                    topLevel._inputManager?.ProcessInput(e);
-                }, (this, e));
-            }
-            else
-            {
-                Logger.TryGet(LogEventLevel.Warning, LogArea.Control)?.Log(
-                    this,
-                    "PlatformImpl is null, couldn't handle input.");
-            }
-        }
-
-        private static IInputElement? FirstEnabledAncestor(IInputElement? hitTestElement)
-        {
-            var candidate = hitTestElement;
-            while (candidate?.IsEffectivelyEnabled == false)
-            {
-                candidate = (candidate as Visual)?.VisualParent as IInputElement;
-            }
-
-            return candidate;
-        }
-
-        private void UpdateCursor() => PlatformImpl?.SetCursor(_cursorOverride?.PlatformImpl ?? _cursor?.PlatformImpl);
-
-        private void SetCursor(Cursor? cursor)
-        {
-            _cursor = cursor;
-            UpdateCursor();
-        }
-        
-        /// <summary>
-        /// This should only be used by InProcessDragSource
-        /// </summary>
-        internal void SetCursorOverride(Cursor? cursor)
-        {
-            _cursorOverride = cursor;
-            UpdateCursor();
-        }
-        
-        private void PointerOverElementOnPropertyChanged(object? sender, AvaloniaPropertyChangedEventArgs e)
-        {
-            if (e.Property == CursorProperty && sender is InputElement inputElement)
-            {
-                SetCursor(inputElement.Cursor);
-            }
-        }
-
         private void GlobalActualThemeVariantChanged(object? sender, EventArgs e)
         {
             SetValue(ActualThemeVariantProperty, ((IThemeVariantHost)sender!).ActualThemeVariant, BindingPriority.Template);
@@ -918,7 +771,6 @@ namespace Avalonia.Controls
 
         private void SceneInvalidated(object? sender, SceneInvalidatedEventArgs e)
         {
-            _pointerOverPreProcessor?.SceneInvalidated(e.DirtyRect);
             UpdateToolTip(e.DirtyRect);
         }
 
@@ -935,12 +787,12 @@ namespace Avalonia.Controls
 
         private void UpdateToolTip(Rect dirtyRect)
         {
-            if (_tooltipService != null && IsPointerOver && _pointerOverPreProcessor?.LastPosition is { } lastPos)
+            if (_tooltipService != null && IsPointerOver && _source.GetLastPointerPosition(this) is { } lastPos)
             {
                 var clientPoint = this.PointToClient(lastPos);
                 if (dirtyRect.Contains(clientPoint))
                 {
-                    _tooltipService.Update(this, this.InputHitTest(clientPoint, enabledElementsOnly: false) as Visual);
+                    _tooltipService.Update(_source, this.InputHitTest(clientPoint, enabledElementsOnly: false) as Visual);
                 }
             }
         }
@@ -964,8 +816,6 @@ namespace Avalonia.Controls
             // Do nothing becuase TopLevel should't apply MirrorTransform on himself.
         }
 
-        ITextInputMethodImpl? ITextInputMethodRoot.InputMethod => PlatformImpl?.TryGetFeature<ITextInputMethodImpl>();
-
         private double ValidateScaling(double scaling)
         {
             if (MathUtilities.IsNegativeOrNonFinite(scaling) || MathUtilities.IsZero(scaling))
@@ -983,49 +833,5 @@ 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)>();

src/Avalonia.Native/TopLevelImpl.cs

@@ -169,7 +169,7 @@ internal class TopLevelImpl : ITopLevelImpl, IFramebufferPlatformSurface
 
     public AutomationPeer? GetAutomationPeer()
     {
-        return _inputRoot is Control c ? ControlAutomationPeer.CreatePeerForElement(c) : null;
+        return _inputRoot?.RootElement is Control c ? ControlAutomationPeer.CreatePeerForElement(c) : null;
     }
 
     public bool RawTextInputEvent(ulong timeStamp, string text)

src/Avalonia.Native/WindowImpl.cs

@@ -6,6 +6,7 @@ using Avalonia.Input.Raw;
 using Avalonia.Input.TextInput;
 using Avalonia.Native.Interop;
 using Avalonia.Platform;
+using Avalonia.Rendering;
 using MicroCom.Runtime;
 
 namespace Avalonia.Native
@@ -136,8 +137,9 @@ namespace Avalonia.Native
             {
                 if(e.Type == RawPointerEventType.LeftButtonDown)
                 {
-                    var window = _inputRoot as Window;
-                    var visual = window?.Renderer.HitTestFirst(e.Position, window, x =>
+                    // TODO: Casts like this are evil
+                    var source = (PresentationSource?)_inputRoot;
+                    var visual = source?.Renderer.HitTestFirst(e.Position, source.RootElement, x =>
                             {
                                 if (x is IInputElement ie && (!ie.IsHitTestVisible || !ie.IsEffectivelyVisible))
                                 {

src/Avalonia.OpenGL/Controls/OpenGlControlBase.cs

@@ -90,7 +90,7 @@ namespace Avalonia.OpenGL.Controls
         protected override void OnAttachedToVisualTree(VisualTreeAttachmentEventArgs e)
         {
             base.OnAttachedToVisualTree(e);
-            _compositor = (this.GetVisualRoot()?.Renderer as IRendererWithCompositor)?.Compositor;
+            _compositor = (this.GetPresentationSource()?.Renderer as IRendererWithCompositor)?.Compositor;
             RequestNextFrameRendering();
         }
 
@@ -201,11 +201,11 @@ namespace Avalonia.OpenGL.Controls
         private void Update()
         {
             _updateQueued = false;
-            if (VisualRoot is not { } visualRoot)
+            if (this.GetPresentationSource() is not { } source)
                 return;
             if(!EnsureInitialized())
                 return;
-            using (_resources.BeginDraw(GetPixelSize(visualRoot)))
+            using (_resources.BeginDraw(GetPixelSize(source)))
                 OnOpenGlRender(_resources.Context.GlInterface, _resources.Fbo);
         }
 
@@ -263,9 +263,9 @@ namespace Avalonia.OpenGL.Controls
             }
         }
 
-        private PixelSize GetPixelSize(IRenderRoot visualRoot)
+        private PixelSize GetPixelSize(IPresentationSource source)
         {
-            var scaling = visualRoot.RenderScaling;
+            var scaling = source.RenderScaling;
             return new PixelSize(Math.Max(1, (int)(Bounds.Width * scaling)),
                 Math.Max(1, (int)(Bounds.Height * scaling)));
         }

src/Avalonia.Themes.Fluent/Accents/SystemAccentColors.cs

@@ -3,6 +3,7 @@ using Avalonia.Controls;
 using Avalonia.Media;
 using Avalonia.Platform;
 using Avalonia.Styling;
+using Avalonia.VisualTree;
 
 namespace Avalonia.Themes.Fluent.Accents;
 
@@ -120,7 +121,7 @@ internal sealed class SystemAccentColors : ResourceProvider
         return owner switch
         {
             Application app => app.PlatformSettings,
-            Visual visual => TopLevel.GetTopLevel(visual)?.PlatformSettings,
+            Visual visual => visual.GetPlatformSettings(),
             _ => null
         };
     }

src/Avalonia.X11/X11Window.cs

@@ -267,7 +267,9 @@ namespace Avalonia.X11
                     ? DBusSystemDialog.TryCreateAsync(Handle)
                     : Task.FromResult<IStorageProvider?>(null),
                 () => GtkSystemDialog.TryCreate(this),
-                () => Task.FromResult(InputRoot is TopLevel tl
+                // TODO: This will be incompatible with "root element is not a TopLevel" scenarios,
+                // we should probably have a separate API for this
+                () => Task.FromResult(InputRoot.RootElement is TopLevel tl
                     ? (IStorageProvider?)new ManagedStorageProvider(tl)
                     : null)
             });

src/Avalonia.X11/X11WindowModes/XEmbedClientWindowMode.cs

@@ -9,7 +9,7 @@ partial class X11Window
 {
     public class XEmbedClientWindowMode : X11WindowMode
     {
-        EmbeddableControlRoot? Root => Window._inputRoot as EmbeddableControlRoot;
+        EmbeddableControlRoot? Root => Window._inputRoot?.RootElement as EmbeddableControlRoot;
         private bool _focusedInEmbedder;
         private bool _embedderActivated;
         private bool _disabled;
@@ -79,7 +79,7 @@ partial class X11Window
                 if (args.PropertyName == nameof(KeyboardDevice.Instance.FocusedElement))
                 {
                     if (KeyboardDevice.Instance.FocusedElement is Visual visual
-                        && visual.VisualRoot is EmbeddableControlRoot root
+                        && TopLevel.GetTopLevel(visual) is EmbeddableControlRoot root
                         && root.PlatformImpl is X11Window window
                         && window._mode is XEmbedClientWindowMode xembedMode
                         && xembedMode._currentEmbedder != IntPtr.Zero)

src/Windows/Avalonia.Win32/OleDropTarget.cs

@@ -209,7 +209,7 @@ namespace Avalonia.Win32
         private Point GetDragLocation(UnmanagedMethods.POINT dragPoint)
         {
             var screenPt = new PixelPoint(dragPoint.X, dragPoint.Y);
-            return ((Visual)_target).PointToClient(screenPt);
+            return _target.RootElement.PointToClient(screenPt);
         }
 
         protected override void Destroyed()

src/Windows/Avalonia.Win32/WindowImpl.AppWndProc.cs

@@ -937,7 +937,7 @@ namespace Avalonia.Win32
                         return IntPtr.Zero;
                     }
                 case WindowsMessage.WM_GETOBJECT:
-                    if ((long)lParam == uiaRootObjectId && UiaCoreTypesApi.IsNetComInteropAvailable && _owner is Control control)
+                    if ((long)lParam == uiaRootObjectId && UiaCoreTypesApi.IsNetComInteropAvailable && _owner?.RootElement is Control control)
                     {
                         var peer = ControlAutomationPeer.CreatePeerForElement(control);
                         var node = AutomationNode.GetOrCreate(peer);

src/Windows/Avalonia.Win32/WindowImpl.CustomCaptionProc.cs

@@ -224,7 +224,7 @@ namespace Avalonia.Win32
         private HitTestValues HitTestVisual(IntPtr lParam)
         {
             var position = PointToClient(PointFromLParam(lParam));
-            if (_owner is Window window)
+            if (_owner?.RootElement is {} window)
             {
                 var visual = window.GetVisualAt(position, x =>
                 {

tests/Avalonia.Base.UnitTests/Input/KeyboardDeviceTests.cs

@@ -12,21 +12,28 @@ namespace Avalonia.Base.UnitTests.Input
         [Fact]
         public void Keypresses_Should_Be_Sent_To_Root_If_No_Focused_Element()
         {
-            var target = new KeyboardDevice();
-            var root = new Mock<IInputRoot>();
-
-            target.ProcessRawEvent(
-                new RawKeyEventArgs(
-                    target,
-                    0,
-                    root.Object,
-                    RawKeyEventType.KeyDown,
-                    Key.A,
-                    RawInputModifiers.None,
-                    PhysicalKey.A,
-                    "a"));
-
-            root.Verify(x => x.RaiseEvent(It.IsAny<KeyEventArgs>()));
+            using (UnitTestApplication.Start(TestServices.FocusableWindow))
+            {
+                var window = new Window();
+                window.FocusManager.ClearFocus();
+                int raised = 0;
+                window.KeyDown += (sender, ev) =>
+                {
+                    if (sender == window && ev.RoutedEvent == InputElement.KeyDownEvent)
+                        raised++;
+                };
+                KeyboardDevice.Instance!.ProcessRawEvent(
+                    new RawKeyEventArgs(
+                        KeyboardDevice.Instance,
+                        0,
+                        window.GetInputRoot()!,
+                        RawKeyEventType.KeyDown,
+                        Key.A,
+                        RawInputModifiers.None,
+                        PhysicalKey.A,
+                        "a"));
+                Assert.Equal(1, raised);
+            }
         }
 
         [Fact]
@@ -61,17 +68,24 @@ namespace Avalonia.Base.UnitTests.Input
         [Fact]
         public void TextInput_Should_Be_Sent_To_Root_If_No_Focused_Element()
         {
-            var target = new KeyboardDevice();
-            var root = new Mock<IInputRoot>();
-
-            target.ProcessRawEvent(
-                new RawTextInputEventArgs(
-                    target,
-                    0,
-                    root.Object,
-                    "Foo"));
-
-            root.Verify(x => x.RaiseEvent(It.IsAny<TextInputEventArgs>()));
+            using (UnitTestApplication.Start(TestServices.FocusableWindow))
+            {
+                var window = new Window();
+                window.FocusManager.ClearFocus();
+                int raised = 0;
+                window.TextInput += (sender, ev) =>
+                {
+                    if (sender == window && ev.RoutedEvent == InputElement.TextInputEvent)
+                        raised++;
+                };
+                KeyboardDevice.Instance!.ProcessRawEvent(
+                    new RawTextInputEventArgs(
+                        KeyboardDevice.Instance,
+                        0,
+                        window.GetInputRoot()!,
+                        "Foo"));
+                Assert.Equal(1, raised);
+            }
         }
 
         [Fact]

tests/Avalonia.Base.UnitTests/Input/PointerOverTests.cs

@@ -246,12 +246,12 @@ namespace Avalonia.Base.UnitTests.Input
 
             // Enter decorator
             SetHit(renderer, decorator);
-            SetMove(deviceMock, root, decorator);
+            SetMove(deviceMock, root.InputRoot, decorator);
             impl.Object.Input!(CreateRawPointerMovedArgs(deviceMock.Object, root));
 
             // Leave decorator
             SetHit(renderer, canvas);
-            SetMove(deviceMock, root, canvas);
+            SetMove(deviceMock, root.InputRoot, canvas);
             impl.Object.Input!(CreateRawPointerMovedArgs(deviceMock.Object, root));
 
             Assert.Equal(
@@ -491,7 +491,7 @@ namespace Avalonia.Base.UnitTests.Input
             Assert.True(canvas.IsPointerOver);
 
             // Send LeaveWindow.
-            impl.Object.Input!(new RawPointerEventArgs(deviceMock.Object, 0, root, RawPointerEventType.LeaveWindow, new Point(), default));
+            impl.Object.Input!(new RawPointerEventArgs(deviceMock.Object, 0, root.InputRoot, RawPointerEventType.LeaveWindow, new Point(), default));
             Assert.False(canvas.IsPointerOver);
 
             Assert.Equal(

tests/Avalonia.Base.UnitTests/Input/PointerTestsBase.cs

@@ -78,26 +78,26 @@ public abstract class PointerTestsBase : ScopedTestBase
 
     protected static RawPointerEventArgs CreateRawPointerArgs(
         IPointerDevice pointerDevice,
-        IInputRoot root,
+        TopLevel root,
         RawPointerEventType type,
         Point? position = default)
     {
-        return new RawPointerEventArgs(pointerDevice, 0, root, type, position ?? default, default);
+        return new RawPointerEventArgs(pointerDevice, 0, root.PresentationSource, type, position ?? default, default);
     }
 
     protected static RawPointerEventArgs CreateRawPointerMovedArgs(
         IPointerDevice pointerDevice,
-        IInputRoot root,
+        TopLevel root,
         Point? position = null)
     {
-        return new RawPointerEventArgs(pointerDevice, 0, root, RawPointerEventType.Move,
+        return new RawPointerEventArgs(pointerDevice, 0, root.PresentationSource, RawPointerEventType.Move,
             position ?? default, default);
     }
 
     protected static PointerEventArgs CreatePointerMovedArgs(
         IInputRoot root, IInputElement? source, Point? position = null)
     {
-        return new PointerEventArgs(InputElement.PointerMovedEvent, source, new Mock<IPointer>().Object, (Visual)root,
+        return new PointerEventArgs(InputElement.PointerMovedEvent, source, new Mock<IPointer>().Object, root.RootElement,
             position ?? default, default, PointerPointProperties.None, KeyModifiers.None);
     }
 

tests/Avalonia.Base.UnitTests/VisualTests.cs

@@ -76,15 +76,16 @@ namespace Avalonia.Base.UnitTests
             
             child1.AttachedToVisualTree += (s, e) =>
             {
-                Assert.Equal(e.Parent, root);
-                Assert.Equal(e.Root, root);
+                // TODO: Tests are running against TestRoot, so behavior DOES NOT match the actual TopLevel.
+                Assert.Equal(e.AttachmentPoint, root);
+                Assert.Equal(e.RootVisual, root);
                 called1 = true;
             };
 
             child2.AttachedToVisualTree += (s, e) =>
             {
-                Assert.Equal(e.Parent, root);
-                Assert.Equal(e.Root, root);
+                Assert.Equal(e.AttachmentPoint, root);
+                Assert.Equal(e.RootVisual, root);
                 called2 = true;
             };
 
@@ -107,15 +108,16 @@ namespace Avalonia.Base.UnitTests
 
             child1.DetachedFromVisualTree += (s, e) =>
             {
-                Assert.Equal(e.Parent, root);
-                Assert.Equal(e.Root, root);
+                // TODO: Tests are running against TestRoot, so behavior DOES NOT match the actual TopLevel.
+                Assert.Equal(e.AttachmentPoint, root);
+                Assert.Equal(e.RootVisual, root);
                 called1 = true;
             };
 
             child2.DetachedFromVisualTree += (s, e) =>
             {
-                Assert.Equal(e.Parent, root);
-                Assert.Equal(e.Root, root);
+                Assert.Equal(e.AttachmentPoint, root);
+                Assert.Equal(e.RootVisual, root);
                 called2 = true;
             };
 

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/HotKeyedControlsTests.cs

@@ -110,7 +110,7 @@ namespace Avalonia.Controls.UnitTests
                 new RawKeyEventArgs(
                     keyboardDevice,
                     0,
-                    root,
+                    root.InputRoot,
                     RawKeyEventType.KeyDown,
                     Key.F,
                     RawInputModifiers.Control,

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/Presenters/ContentPresenterTests_Standalone.cs

@@ -57,7 +57,7 @@ namespace Avalonia.Controls.UnitTests.Presenters
 
             var parentMock = new Mock<Control>();
             parentMock.As<IContentPresenterHost>();
-            parentMock.As<IRenderRoot>();
+            parentMock.As<IPresentationSource>();
             parentMock.As<ILogicalRoot>();
 
             (target as ISetLogicalParent).SetParent(parentMock.Object);
@@ -102,7 +102,7 @@ namespace Avalonia.Controls.UnitTests.Presenters
             };
 
             var parentMock = new Mock<Control>();
-            parentMock.As<IRenderRoot>();
+            parentMock.As<IPresentationSource>();
             parentMock.As<ILogicalRoot>();
             parentMock.As<ILogical>().SetupGet(l => l.IsAttachedToLogicalTree).Returns(true);
 
@@ -148,7 +148,7 @@ namespace Avalonia.Controls.UnitTests.Presenters
 
             var parentMock = new Mock<Control>();
             parentMock.As<IContentPresenterHost>();
-            parentMock.As<IRenderRoot>();
+            parentMock.As<IPresentationSource>();
             parentMock.As<ILogicalRoot>();
 
             (target as ISetLogicalParent).SetParent(parentMock.Object);

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

@@ -657,13 +657,22 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
                 button.Focus();
 
-                var inputRoot = Assert.IsAssignableFrom<IInputRoot>(popup.Host);
+                var inputRoot = ((Visual)popup.Host!).GetInputRoot();
 
-                var focusManager = inputRoot.FocusManager!;
+                var focusManager = inputRoot!.FocusManager!;
                 Assert.Same(button, focusManager.GetFocusedElement());
 
                 //Ensure focus remains in the popup
-                inputRoot.KeyboardNavigationHandler!.Move(focusManager.GetFocusedElement()!, NavigationDirection.Next);
+#pragma warning disable CS0618 // Type or member is obsolete
+                var handler = popup.Host switch
+                {
+                    PopupRoot popupRoot => popupRoot.Tests_KeyboardNavigationHandler,
+                    OverlayPopupHost overlayPopupHost => overlayPopupHost.Tests_KeyboardNavigationHandler,
+                    _ => throw new InvalidOperationException("Unknown popup host type")
+                };
+                
+                handler.Move(focusManager.GetFocusedElement()!, NavigationDirection.Next);
+#pragma warning restore CS0618 // Type or member is obsolete
                 Assert.Same(textBox, focusManager.GetFocusedElement());
 
                 popup.Close();
@@ -702,9 +711,9 @@ namespace Avalonia.Controls.UnitTests.Primitives
 
                 button.Focus();
 
-                var inputRoot = Assert.IsAssignableFrom<IInputRoot>(popup.Host);
+                var inputRoot = ((Visual)popup.Host!).GetInputRoot();
 
-                var focusManager = inputRoot.FocusManager!;
+                var focusManager = inputRoot!.FocusManager!;
                 Assert.Same(button, focusManager.GetFocusedElement());
 
                 border1.Child = null;
@@ -1170,7 +1179,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
                 var ev = new PointerPressedEventArgs(
                     popupContent,
                     pointer,
-                    (PopupRoot)popupContent.VisualRoot!,
+                    (PopupRoot)TopLevel.GetTopLevel(popupContent)!,
                     new Point(50 , 50),
                     0,
                     new PointerPointProperties(RawInputModifiers.None, PointerUpdateKind.LeftButtonPressed),