确定oneshot和non-oneshot AnimationDrawables的完成

Question

我试图找到一个能够顺利切换AnimationDrawables的解决方案。要做到这一点，我觉得有必要知道AnimationDrawable何时完成动画。我已经看过其他堆栈溢出解决方案，但我找不到适用于oneshot=true和oneshot=false动画的解决方案。

此处我的自定义AnimationDrawable：

public class LifecycleAnimationDrawable extends AnimationDrawable {

    private boolean finishedAnimating = false;

    private AnimationDrawableLifecycleListener animationDrawableLifecycleListener;

    public interface AnimationDrawableLifecycleListener {
        void onAnimationStart();
        void onAnimationFinished();
    }

    public LifecycleAnimationDrawable(AnimationDrawable drawable, AnimationDrawableLifecycleListener animationDrawableLifecycleListener) {
        this.animationDrawableLifecycleListener = animationDrawableLifecycleListener;
        for (int i = 0; i < drawable.getNumberOfFrames(); i++) {
            addFrame(drawable.getFrame(i), drawable.getDuration(i));
        }
        setOneShot(drawable.isOneShot());
    }

    @Override
    public void start() {
        super.start();
        if (animationDrawableLifecycleListener != null) {
            animationDrawableLifecycleListener.onAnimationStart();
        }
    }

    @Override
    public boolean selectDrawable(int index) {
        boolean result = super.selectDrawable(index);
        if (index != 0 && index == getNumberOfFrames() - 1) {
            if (!finishedAnimating || !isOneShot()) {
                finishedAnimating = true;
                if (animationDrawableLifecycleListener != null) {
                    animationDrawableLifecycleListener.onAnimationFinished();
                }
            }
        }
        return result;
    }
}

我不确定我做错了什么，但我注意到索引似乎总是为0.

任何帮助或见解都将不胜感激。