SwipeRefreshLayout.java 文件源码

private void startScaleDownReturnToStartAnimation(int from,
        Animation.AnimationListener listener) {
    mFrom = from;
    if (isAlphaUsedForScale()) {
        mStartingScale = mProgress.getAlpha();
    } else {
        mStartingScale = ViewCompat.getScaleX(mCircleView);
    }
    mScaleDownToStartAnimation = new Animation() {
        @Override
        public void applyTransformation(float interpolatedTime, Transformation t) {
            float targetScale = (mStartingScale + (-mStartingScale  * interpolatedTime));
            setAnimationProgress(targetScale);
            moveToStart(interpolatedTime);
        }
    };
    mScaleDownToStartAnimation.setDuration(SCALE_DOWN_DURATION);
    if (listener != null) {
        mCircleView.setAnimationListener(listener);
    }
    mCircleView.clearAnimation();
    mCircleView.startAnimation(mScaleDownToStartAnimation);
}