FocusAdorner remains after the element has been hidden

[impworks]

Describe the bug

When using tab navigation and pressing the button that hides its container (e.g. a dialog box), the focus adorner remains.

To Reproduce

1. Download the minirepro source:
   https://github.com/impworks/avalonia-focus-bug-repro

2. Start the app

3. Click the "Open" button

4. Press "Tab" until the "Close" button is in focus

5. Press "Space" to close the dialog

Expected behavior

Focus adorner disappears when the element is hidden

Avalonia version

11.3.0

OS

Windows

Additional context

There is a temporary workaround to use FocusManager.ClearFocus in the Close command.
However, this method is marked as [Obsolete] and cannot be safely used.

[TomEdwardsEnscape]

The bug is more fundamental than this. The button never loses focus at all, and can still be pressed with the spacebar even though no longer visible.

This doesn't match WPF's behaviour, where a hidden or collapsed button loses focus and can no longer be clicked.

[TomEdwardsEnscape]

It doesn't lose focus because InputElement doesn't know when it is hidden. If IsVisible is set directly you get a property changed, but sadly IsVisible doesn't tell you whether the control is visible. You need to check IsEffectivelyVisible, which raises no events.

This problem has been discussed before in #15413.