code: def _unhandled_event_default(event):
          
          if isinstance(event, KeyboardEvent):
              c = event.key_code
              if c in (ord("X"), ord("x"), ord("Q"), ord("q")):
                  raise StopApplication("User terminated app")
              if c in (ord(" "), ord("\n"), ord("\r")):
                  raise NextScene()
docs: Default unhandled event handler for handling simple scene navigation.