一个按键控制动画播放与暂停

key = {};
key.onKeyDown = function() {
if (Key.isDown(Key.SPACE) and !down) {
down = !down;
!op ? (m.stop(), op=!op) : (op=!op, m.play());
}
};
key.onKeyUp = function() {
down = !down;
};
Key.addListener(key);