Addressed review

Author: kekekeks

src/Avalonia.X11/X11WindowModes/XEmbedClientWindowMode.cs

@@ -14,7 +14,6 @@ public class XEmbedClientWindowMode : X11WindowMode
         EmbeddableControlRoot? Root => Window._inputRoot as EmbeddableControlRoot;
         private bool _focusedInEmbedder;
         private bool _embedderActivated;
-        private IInputElement? _savedFocus;
         private bool _disabled;
         private IntPtr _currentEmbedder;
         private bool _suppressConfigureEvents;
@@ -25,6 +24,14 @@ public double Scaling
             get => Window._scalingOverride ?? 1;
             set => Window._scalingOverride = value;
         }
+        
+        private WeakReference<IInputElement>? _savedFocus;
+
+        private IInputElement? SavedFocus
+        {
+            get => _savedFocus?.TryGetTarget(out var target) == true ? target : null;
+            set => _savedFocus = value == null ? null : new WeakReference<IInputElement>(value);
+        }
 
         public override void OnHandleCreated(IntPtr handle)
         {
@@ -76,7 +83,7 @@ static XEmbedClientWindowMode()
                         && window._mode is XEmbedClientWindowMode xembedMode
                         && xembedMode._currentEmbedder != IntPtr.Zero)
                     {
-                        xembedMode._savedFocus = KeyboardDevice.Instance.FocusedElement;
+                        xembedMode.SavedFocus = KeyboardDevice.Instance.FocusedElement;
                         xembedMode.SendXEmbedMessage(XEmbedMessage.RequestFocus);
                     }
                 }
@@ -131,13 +138,12 @@ private void UpdateActivation()
             if (active)
             {
                 ((FocusManager?)Root?.FocusManager)?.SetFocusScope(Root);
-                if (_savedFocus != null) 
-                    KeyboardDevice.Instance?.SetFocusedElement(_savedFocus, NavigationMethod.Unspecified, KeyModifiers.None);
-                _savedFocus = null;
+                SavedFocus?.Focus();
+                SavedFocus = null;
             }
             else
             {
-                _savedFocus = Root?.IsKeyboardFocusWithin == true ? Root.FocusManager?.GetFocusedElement() : null;
+                SavedFocus = Root?.IsKeyboardFocusWithin == true ? Root.FocusManager?.GetFocusedElement() : null;
                 Window.LostFocus?.Invoke();
             }
         }