public void addTableModelListener(WTableModelListener listener){
  if (listener == null) {
    return;
  }
  if (!m_listeners.contains(listener)) {
    m_listeners.add(listener);
  }
  return;
}

public void addTableModelListener ( WTableModelListener listener ) { if ( listener == null ) { return ; } if ( ! m_listeners . contains ( listener ) ) { m_listeners . add ( listener ) ; } return ; }
add a listener for events from the data model . the listener will only be added if it doesn ' t already exist .
