HoldingDrawable.java 文件源码

private ValueAnimator createCollapseValueAnimator() {
    ValueAnimator animator = ValueAnimator.ofFloat(1f, 0f);
    animator.setDuration(DEFAULT_ANIMATION_DURATION_COLLAPSE);
    animator.setInterpolator(new AccelerateInterpolator());
    animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
        @Override
        public void onAnimationUpdate(ValueAnimator valueAnimator) {
            mExpandedScaleFactor[0] = (float) valueAnimator.getAnimatedValue();
            invalidateSelf();
        }
    });
    animator.addListener(new AnimatorListenerAdapter() {
        @Override
        public void onAnimationEnd(Animator animation) {
            notifyCollapsed();
        }
    });
    return animator;
}