/****************************************************************** * * CyberUtil for Java * * Copyright (C) Satoshi Konno 2002 * * File: ListenerList.java * * Revision; * * 12/30/02 * - first revision. * ******************************************************************/ package org.cybergarage.util; import java.util.Vector; public class ListenerList extends Vector<Object> { public boolean add(Object obj) { if (0 <= indexOf(obj)) return false; return super.add(obj); } }