RecyclerAnimationAdapter.java

public class RecyclerAnimationAdapter extends RecyclerView.Adapter<RecyclerAnimationAdapter.ViewHolder> {


    Context context;
    List<Person> list;
    long DURATION = 500;
    private boolean on_attach = true;


    public RecyclerAnimationAdapter(Context context, List<Person> personList) {

        this.context = context;
        this.list = personList;
    }

    @NonNull
    @Override
    public ViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
        View view = LayoutInflater.from(context).inflate(R.layout.item_list, null);

        return new ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull ViewHolder holder, int i) {

        holder.name.setText(list.get(i).name);
        Picasso.get().load(list.get(i).image).into(holder.imageView);

        setAnimation(holder.itemView, i);

    }

    @Override
    public int getItemCount() {
        return list.size();
    }

    @Override
    public void onAttachedToRecyclerView(@NonNull RecyclerView recyclerView) {

        recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
            @Override
            public void onScrollStateChanged(@NonNull RecyclerView recyclerView, int newState) {
                Log.d(TAG, "onScrollStateChanged: Called " + newState);
                on_attach = false;
                super.onScrollStateChanged(recyclerView, newState);
            }
        });

        super.onAttachedToRecyclerView(recyclerView);
    }

    private void setAnimation(View itemView, int i) {
        if(!on_attach){
            i = -1;
        }
        boolean isNotFirstItem = i == -1;
        i++;
        itemView.setAlpha(0.f);
        AnimatorSet animatorSet = new AnimatorSet();
        ObjectAnimator animator = ObjectAnimator.ofFloat(itemView, "alpha", 0.f, 0.5f, 1.0f);
        ObjectAnimator.ofFloat(itemView, "alpha", 0.f).start();
        animator.setStartDelay(isNotFirstItem ? DURATION / 2 : (i * DURATION / 3));
        animator.setDuration(500);
        animatorSet.play(animator);
        animator.start();
    }


    public class ViewHolder extends RecyclerView.ViewHolder {

        CircleImageView imageView;
        TextView name;
        View parentLayout;

        public ViewHolder(@NonNull View itemView) {
            super(itemView);

            imageView = itemView.findViewById(R.id.image);
            name = itemView.findViewById(R.id.name);
            parentLayout = itemView.findViewById(R.id.parentLayout);
        }
    }
}