BallPulseIndicator.java 文件源码

@Override
public List<Animator> createAnimation() {
    List<Animator> animators=new ArrayList<>();
    int[] delays=new int[]{120,240,360};
    for (int i = 0; i < 3; i++) {
        final int index=i;

        ValueAnimator scaleAnim=ValueAnimator.ofFloat(1,0.3f,1);

        scaleAnim.setDuration(750);
        scaleAnim.setRepeatCount(-1);
        scaleAnim.setStartDelay(delays[i]);

        scaleAnim.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
            @Override
            public void onAnimationUpdate(ValueAnimator animation) {
                scaleFloats[index] = (float) animation.getAnimatedValue();
                postInvalidate();

            }
        });
        scaleAnim.start();
        animators.add(scaleAnim);
    }
    return animators;
}