@Override
    public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
      if (mOnScrollListener != null) {
        mOnScrollListener.onScrollStateChanged(recyclerView, newState);
      }

      super.onScrollStateChanged(recyclerView, newState);
    }
    @Override
    public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
      if (mOnScrollListener != null) {
        mOnScrollListener.onScrolled(recyclerView, dx, dy);
      }

      super.onScrolled(recyclerView, dx, dy);
    }