SwipeHelper.java 文件源码

private void snapChild(final View animView, final float targetLeft, float velocity) {
    final boolean canBeDismissed = mCallback.canChildBeDismissed(animView);
    AnimatorUpdateListener updateListener = new AnimatorUpdateListener() {
        public void onAnimationUpdate(ValueAnimator animation) {
            onTranslationUpdate(animView, (float) animation.getAnimatedValue(), canBeDismissed);
        }
    };

    Animator anim = getViewTranslationAnimator(animView, targetLeft, updateListener);
    if (anim == null) {
        return;
    }
    int duration = SNAP_ANIM_LEN;
    anim.setDuration(duration);
    anim.addListener(new AnimatorListenerAdapter() {
        public void onAnimationEnd(Animator animator) {
            mSnappingChild = false;
            updateSwipeProgressFromOffset(animView, canBeDismissed);
            mCallback.onChildSnappedBack(animView, targetLeft);
        }
    });
    prepareSnapBackAnimation(animView, anim);
    mSnappingChild = true;
    anim.start();
}