Fix Toplevel not losing focus with native implementation deactivates. (#20768)

* add failing test

* query the toplevel of the currently focused control instead when losing focus

src/Avalonia.Controls/TopLevel.cs

@@ -257,9 +257,7 @@ namespace Avalonia.Controls
 
             impl.LostFocus += PlatformImpl_LostFocus;
 
-
-
-            if(impl.TryGetFeature<ISystemNavigationManagerImpl>() is {} systemNavigationManager)
+            if (impl.TryGetFeature<ISystemNavigationManagerImpl>() is { } systemNavigationManager)
             {
                 systemNavigationManager.BackRequested += (_, e) =>
                 {
@@ -286,14 +284,14 @@ namespace Avalonia.Controls
                             KeyModifiers = (KeyModifiers)rawKeyEventArgs.Modifiers,
                             Key = rawKeyEventArgs.Key,
                             PhysicalKey = rawKeyEventArgs.PhysicalKey,
-                            KeyDeviceType= rawKeyEventArgs.KeyDeviceType,
+                            KeyDeviceType = rawKeyEventArgs.KeyDeviceType,
                             KeySymbol = rawKeyEventArgs.KeySymbol
                         };
 
-                        backRequested = keymap.Any( key => key.Matches(keyEvent));
+                        backRequested = keymap.Any(key => key.Matches(keyEvent));
                     }
                 }
-                else if(e is RawPointerEventArgs pointerEventArgs)
+                else if (e is RawPointerEventArgs pointerEventArgs)
                 {
                     backRequested = pointerEventArgs.Type == RawPointerEventType.XButton1Down;
                 }
@@ -602,7 +600,7 @@ namespace Avalonia.Controls
         private void InvalidateChildInsetsPadding()
         {
             if (Content is Control child
-                && InsetsManager is {} insetsManager)
+                && InsetsManager is { } insetsManager)
             {
                 insetsManager.SafeAreaChanged -= InsetsManagerOnSafeAreaChanged;
                 _insetsPaddings?.Dispose();
@@ -803,11 +801,7 @@ namespace Avalonia.Controls
 
         void PlatformImpl_LostFocus()
         {
-            var focused = (Visual?)FocusManager?.GetFocusedElement();
-            if (focused == null)
-                return;
-            while (focused.VisualParent != null)
-                focused = focused.VisualParent;
+            var focused = TopLevel.GetTopLevel((Visual?)FocusManager?.GetFocusedElement());
 
             if (focused == this)
                 KeyboardDevice.Instance?.SetFocusedElement(null, NavigationMethod.Unspecified, KeyModifiers.None, false);

tests/Avalonia.Controls.UnitTests/TopLevelTests.cs

@@ -253,6 +253,34 @@ namespace Avalonia.Controls.UnitTests
             }
         }
 
+        [Fact]
+        public void TopLevel_Should_Unfocus_When_Impl_Focus_Is_Lost()
+        {
+            using (UnitTestApplication.Start(TestServices.RealFocus))
+            {
+                var impl = CreateMockTopLevelImpl(true);
+                var content = new TextBox()
+                {
+                    Focusable = true
+                };
+                var target = new TestTopLevel(impl.Object)
+                {
+                    Template = CreateTemplate(),
+                    Focusable = true,
+                    Content = content
+                };
+
+                target.LayoutManager.ExecuteInitialLayoutPass();
+
+                content.Focus();
+                Assert.True(content.IsFocused);
+
+                impl.Object.LostFocus?.Invoke();
+
+                Assert.False(content.IsFocused);
+            }
+        }
+
         [Fact]
         public void Reacts_To_Changes_In_Global_Styles()
         {