我有一個 clicklistener 擴(kuò)展類，旨在緩存 actor 在 touchDown 期間的任何當(dāng)前動作，并在觸發(fā) touchUp 時將其分配回去。但是，它不適用于序列或并行操作。public class MyClickListener extends ClickListener {    public Actor actor;    private final Array<Action> cachedActions = new Array<Action>();    @Override    public void touchUp(InputEvent event, float x, float y, int pointer, int button) {        super.touchUp(event, x, y, pointer, button);        actor = event.getListenerActor();        actor.addAction(btnScaleBackActions());        for(Action action:cachedActions)        {            //action.reset(); // i wants the actor to continue at where it stop            action.setTarget(actor);            action.setActor(actor);            actor.addAction(action);        }        cachedActions.clear();    }    @Override    public boolean touchDown(InputEvent event, float x, float y, int pointer, int button) {        if(pointer==0)        {            actor = event.getListenerActor();            actor.setScale(0.9f);            cachedActions.addAll(actor.getActions());            actor.clearActions();            return super.touchDown(event, x, y, pointer, button);        }        else        {            return false;        }    }我的按鈕測試：// button touchUp continue its previous action at where it stopbtn1.addAction(Actions.scaleBy(1,1,3));// button touchUp not continue it previous actions and complete stopbtn2.addAction(sequence(Actions.scaleBy(1,1,3))); // button touchUp give nullException errorbtn3.addAction(forever(Actions.scaleBy(1,1,3)));//error :Exception in thread "LWJGL Application" java.lang.NullPointerException        at com.badlogic.gdx.scenes.scene2d.actions.RepeatAction.delegate(RepeatAction.java:29)        at com.badlogic.gdx.scenes.scene2d.actions.DelegateAction.act(DelegateAction.java:43)是否可以在 myClickListener 類停止的地方繼續(xù)序列/并行操作？