/* * This file is part of the Java SIP library, an open source SIP library. Please see * http://collaboration.mitre.org/sip for more information *  * Copyright (c) 2001 The MITRE Corporation  *  * * This library is free software; you can redistribute it and/or modify it * under the terms of the GNU Library General Public License as published by * the Free Software Foundation; either version 2 of the License, or (at your * option) any later version. *  * This library is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public * License for more details. *  * You should have received a copy of the GNU Library General Public License * along with this library; see the file COPYING.LIB.  If not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, * MA 02111-1307, USA. * *//** * Maintains listener list for CallEvents * * @author S.R.Jones * @version 1 */package org.mitre.jsip.event;import java.awt.AWTEventMulticaster;import java.util.EventListener;public class CallEventMulticaster extends AWTEventMulticaster implements CallListener{    protected CallEventMulticaster( EventListener a, EventListener b ) {	super( a, b );    }    public static CallListener add( CallListener a, CallListener b ) {	return (CallListener) addInternal( a, b );    }    public static CallListener remove( CallListener cel, CallListener cel_old ) {	return (CallListener) removeInternal( cel, cel_old );    }    public void responseReceived( CallEvent ce ) {	if ( a != null ) ( (CallListener) a ).responseReceived(ce);	if ( b != null ) ( (CallListener) b ).responseReceived(ce);    }    public void requestReceived( CallEvent ce ) {	if ( a != null ) ( (CallListener) a ).requestReceived(ce);	if ( b != null ) ( (CallListener) b ).requestReceived(ce);    }    protected static EventListener addInternal( EventListener a, EventListener b ) {	if ( a == null ) return b;	if ( b == null ) return a;	return new CallEventMulticaster( a, b );    }    protected EventListener remove( EventListener old_listener ) {	if ( old_listener == a ) return b;	if ( old_listener == b ) return a;	EventListener a2 = removeInternal(a, old_listener);	EventListener b2 = removeInternal(b, old_listener);	if ( a2 == a && b2 == b ) return this;	return addInternal( a2, b2 );    }}