I want to know about this variable's purpose from InstaMaterial(of Miroslaw Stanek)

Question

Please check this page -> http://frogermcs.github.io/InstaMaterial-concept-part-5-like_action_effects/

I'm just learning from InstaMaterial's source code. I almost understood most codes. But I can't understand what does "likeAnimations" variable from FeedAdapter standing for.

I know it is a Hash Map. I thought it is for preventing duplicated call. It was not though...

Can anybody explain about this variable's purpose?

The full source code of FeedAdapter is here -> https://github.com/frogermcs/InstaMaterial/blob/master/app/src/main/java/io/github/froger/instamaterial/ui/adapter/FeedAdapter.java

I will be thankful in any advances.

At the Member Field.

private final Map<RecyclerView.ViewHolder, AnimatorSet> likeAnimations = new HashMap<>();

At the "animatePhotoLike" Method.

private void animatePhotoLike(final CellFeedViewHolder holder) {
if (!likeAnimations.containsKey(holder)) {
    holder.vBgLike.setVisibility(View.VISIBLE);
    holder.ivLike.setVisibility(View.VISIBLE);

    holder.vBgLike.setScaleY(0.1f);
    holder.vBgLike.setScaleX(0.1f);
    holder.vBgLike.setAlpha(1f);
    holder.ivLike.setScaleY(0.1f);
    holder.ivLike.setScaleX(0.1f);

    AnimatorSet animatorSet = new AnimatorSet();
    // It puts 'holder' and 'AnimatorSet' into this HashMap before starting animations.
    likeAnimations.put(holder, animatorSet);

    ObjectAnimator bgScaleYAnim = ObjectAnimator.ofFloat(holder.vBgLike, "scaleY", 0.1f, 1f);
    bgScaleYAnim.setDuration(200);
    bgScaleYAnim.setInterpolator(DECCELERATE_INTERPOLATOR);
    ObjectAnimator bgScaleXAnim = ObjectAnimator.ofFloat(holder.vBgLike, "scaleX", 0.1f, 1f);
    bgScaleXAnim.setDuration(200);
    bgScaleXAnim.setInterpolator(DECCELERATE_INTERPOLATOR);
    ObjectAnimator bgAlphaAnim = ObjectAnimator.ofFloat(holder.vBgLike, "alpha", 1f, 0f);
    bgAlphaAnim.setDuration(200);
    bgAlphaAnim.setStartDelay(150);
    bgAlphaAnim.setInterpolator(DECCELERATE_INTERPOLATOR);

    ObjectAnimator imgScaleUpYAnim = ObjectAnimator.ofFloat(holder.ivLike, "scaleY", 0.1f, 1f);
    imgScaleUpYAnim.setDuration(300);
    imgScaleUpYAnim.setInterpolator(DECCELERATE_INTERPOLATOR);
    ObjectAnimator imgScaleUpXAnim = ObjectAnimator.ofFloat(holder.ivLike, "scaleX", 0.1f, 1f);
    imgScaleUpXAnim.setDuration(300);
    imgScaleUpXAnim.setInterpolator(DECCELERATE_INTERPOLATOR);

    ObjectAnimator imgScaleDownYAnim = ObjectAnimator.ofFloat(holder.ivLike, "scaleY", 1f, 0f);
    imgScaleDownYAnim.setDuration(300);
    imgScaleDownYAnim.setInterpolator(ACCELERATE_INTERPOLATOR);
    ObjectAnimator imgScaleDownXAnim = ObjectAnimator.ofFloat(holder.ivLike, "scaleX", 1f, 0f);
    imgScaleDownXAnim.setDuration(300);
    imgScaleDownXAnim.setInterpolator(ACCELERATE_INTERPOLATOR);

    animatorSet.playTogether(bgScaleYAnim, bgScaleXAnim, bgAlphaAnim, imgScaleUpYAnim, imgScaleUpXAnim);
    animatorSet.play(imgScaleDownYAnim).with(imgScaleDownXAnim).after(imgScaleUpYAnim);

    animatorSet.addListener(new AnimatorListenerAdapter() {
        @Override
        public void onAnimationEnd(Animator animation) {
            // It removes the item from the HashMap which contains this holder as key value when all animations are finisehd.
            resetLikeAnimationState(holder);
        }
    });
    animatorSet.start();
}}

At the "resetLikeAnimationState" Method.

private void resetLikeAnimationState(CellFeedViewHolder holder) {
    likeAnimations.remove(holder);
    holder.vBgLike.setVisibility(View.GONE);
    holder.ivLike.setVisibility(View.GONE);
}

Answer 1

Thanks, Miroslaw!

(just as miroslaw commented under my question)