Make automation to target FocusRoot

src/Avalonia.Base/Input/IInputRoot.cs

@@ -30,6 +30,8 @@ namespace Avalonia.Input
         // HACK: This is a temporary hack for "default focus" concept. 
         // If nothing is focused we send keyboard events to Window. Since for now we always
         // control PresentationSource, we simply pass the TopLevel as a separate parameter there.
-        internal InputElement FocusRoot { get; }
+        // It's also currently used by automation since we have special WindowAutomationPeer which needs to target the
+        // window itself
+        public InputElement FocusRoot { get; }
     }
 }

src/Avalonia.Native/TopLevelImpl.cs

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

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?.RootElement is Control control)
+                    if ((long)lParam == uiaRootObjectId && UiaCoreTypesApi.IsNetComInteropAvailable && _owner?.FocusRoot is Control control)
                     {
                         var peer = ControlAutomationPeer.CreatePeerForElement(control);
                         var node = AutomationNode.GetOrCreate(peer);