code: @Override
      public void onBrowserEvent(Event event) {
  
          switch (DOM.eventGetType(event)) {
              case Event.ONMOUSEUP:
                  Event.releaseCapture(getElement());
                  m_capturedMouse = false;
                  break;
              case Event.ONMOUSEDOWN:
                  Event.setCapture(getElement());
                  m_capturedMouse = true;
                  //$FALL-THROUGH$
              case Event.ONMOUSEMOVE:
                  if (m_capturedMouse) {
                      event.preventDefault();
                      double abolut_top = getAbsoluteTop();
                      int y = ((event.getClientY() - (int)abolut_top) + Window.getScrollTop());
                      setSliderPosition(y);
                      if (m_parent != null) {
                          m_parent.onBarSelected(y);
                      }
                  }
                  //$FALL-THROUGH$
              default:
  
          }
      }
docs: Fired whenever a browser event is received.<p>
  @param event Event to process