pub fn update_view_focus_state(&mut self, is_focused: bool) -> Option<QueuedEvents> {
        let mut state = self.associated.ivars().state.borrow_mut();
        state.adapter.update_view_focus_state(is_focused)
    }
Update the tree state based on whether the window is focused.

If a [`QueuedEvents`] instance is returned, the caller must call
[`QueuedEvents::raise`] on it.
platforms/macos/src/subclass.rs