code: private void setSelectHeight(int height) {
  
          m_markerStyle.setHeight(height, Unit.PX);
  
          m_overlayBottomStyle.setHeight(m_elementHeight - m_currentSelection.getTop() - height, Unit.PX);
  
          m_currentSelection.setHeight(height);
      }
docs: Adjusts the select area height, while keeping the Y position of the top/left corner.<p>
  
  @param height the new height