pub fn handle_window_focus(&mut self, handle: &WindowHandle<H>) {
        match self.focus_manager.behaviour {
            FocusBehaviour::Sloppy if self.focus_manager.sloppy_mouse_follows_focus => {
                let act = DisplayAction::MoveMouseOver(*handle, false);
                self.actions.push_back(act);
            }
            _ => self.focus_window(handle),
        }
    }
Focuses a window based upon the `FocusBehaviour`
leftwm-core/src/handlers/focus_handler.rs