code: public void setPosition(int height, int width, int positionLeft, int positionTop) {
  
          positionLeft -= m_borderOffset;
  
          // make sure highlighting does not introduce additional horizontal scroll-bars
          if ((m_positioningParent == null) && (positionLeft < 0)) {
              // position left should not be negative
              width += positionLeft;
              positionLeft = 0;
          }
          width += (2 * m_borderOffset) - BORDER_WIDTH;
          if ((m_positioningParent == null)
              && (Window.getClientWidth() < (width + positionLeft))
              && (Window.getScrollLeft() == 0)) {
              // highlighting should not extend over the right hand
              width = Window.getClientWidth() - (positionLeft + BORDER_WIDTH);
          }
          Style style = getElement().getStyle();
          style.setLeft(positionLeft, Unit.PX);
          style.setTop(positionTop - m_borderOffset, Unit.PX);
          setHeight((height + (2 * m_borderOffset)) - BORDER_WIDTH);
          setWidth(width);
      }
docs: Sets the border position.<p>
  
  @param height the height
  @param width the width
  @param positionLeft the absolute left position
  @param positionTop the absolute top position