Fixed focus not being cleared when a parent of the focused element is hidden (#18916)

Enabled the relevant test

Author: TomEdwardsEnscape

src/Avalonia.Base/Input/InputElement.cs

@@ -720,9 +720,19 @@ protected override void OnPropertyChanged(AvaloniaPropertyChangedEventArgs chang
             {
                 PseudoClasses.Set(":focus-within", change.GetNewValue<bool>());
             }
-            else if (change.Property == IsVisibleProperty && !change.GetNewValue<bool>() && IsFocused)
+            else if (change.Property == IsVisibleProperty)
             {
-                FocusManager.GetFocusManager(this)?.ClearFocus();
+                if (!change.GetNewValue<bool>() && IsKeyboardFocusWithin && FocusManager.GetFocusManager(this) is { } focusManager)
+                {
+                    if (focusManager.GetFocusedElement() is { } focusedElement && VisualParent != null)
+                    {
+                        focusManager.ClearFocusOnElementRemoved(focusedElement, VisualParent);
+                    }
+                    else
+                    {
+                        focusManager.ClearFocus();
+                    }
+                }
             }
         }
 

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

@@ -203,7 +203,7 @@ public void Focus_Should_Be_Cleared_When_Control_Is_Hidden()
             }
         }
 
-        [Fact(Skip = "Need to implement IsEffectivelyVisible change notifications.")]
+        [Fact]
         public void Focus_Should_Be_Cleared_When_Control_Is_Effectively_Hidden()
         {
             Border container;