def _arrow_key_pressed(self, event):
        """
        Called when an arrow key was pressed.
        """
        d = event.keysym.lower()
        if d == "left":
            # self.parent.arrowLeftAction()
            self.stash.user_action_proxy.vk_tapped(K_LEFT)
        elif d == "right":
            # self.parent.arrowRightAction()
            self.stash.user_action_proxy.vk_tapped(K_RIGHT)
        elif d == "up":
            # self.parent.arrowUpAction()
            self.stash.user_action_proxy.vk_tapped(K_HUP)
        elif d == "down":
            # self.parent.arrowDownAction()
            self.stash.user_action_proxy.vk_tapped(K_HDN)
        else:
            raise ValueError("Unknown key: {!r}".format(d))
        return "break"

        Called when an arrow key was pressed.
        
system/shui/tkui.py