public void handlePopupMenu(MouseEvent e){
  _list.setSelectedIndex(_list.locationToIndex(e.getPoint()));
  _popup.show(_list,e.getX(),e.getY());
}

public void handlePopupMenu ( MouseEvent e ) { _list . setSelectedIndex ( _list . locationToIndex ( e . getPoint ( ) ) ) ; _popup . show ( _list , e . getX ( ) , e . getY ( ) ) ; }
handles a trigger to the popup menu .
