code: @Override
      protected void onScrollChanged(int l, int t, int oldl, int oldt) {
          super.onScrollChanged(l, t, oldl, oldt);
          
          View title = getChildAt(0);
          if (title != null)   // undo horizontal scroll, so that title scrolls only vertically
             title.offsetLeftAndRight(l - title.getLeft());
  
          if (mOnScrollChangedCallback != null)
              mOnScrollChangedCallback.onScroll(l, t);
      }
docs: /*
  Scroll