code: @Override
  	public int computeVerticalScrollRange() {
  		final int count = getChildCount();
  		final int contentHeight = getHeight() - getPaddingBottom() - getPaddingTop();
  		if (count == 0) {
  			return contentHeight;
  		}
  
  		int scrollRange = getChildAt(0).getBottom();
  		final int scrollY = getScrollY();
  		final int overscrollBottom = Math.max(0, scrollRange - contentHeight);
  		if (scrollY < 0) {
  			scrollRange -= scrollY;
  		} else if (scrollY > overscrollBottom) {
  			scrollRange += scrollY - overscrollBottom;
  		}
  
  		return scrollRange;
  	}
docs: <p>The scroll range of a scroll view is the overall height of all of its
  children.</p>
  @hide