001    /*
002     * hammurapi-rules @mesopotamia.version@
003     * Hammurapi rules engine. 
004     * Copyright (C) 2005  Hammurapi Group
005     *
006     * This program is free software; you can redistribute it and/or
007     * modify it under the terms of the GNU Lesser General Public
008     * License as published by the Free Software Foundation; either
009     * version 2 of the License, or (at your option) any later version.
010     *
011     * This program is distributed in the hope that it will be useful,
012     * but WITHOUT ANY WARRANTY; without even the implied warranty of
013     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014     * Lesser General Public License for more details.
015     *
016     * You should have received a copy of the GNU Lesser General Public
017     * License along with this library; if not, write to the Free Software
018     * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
019     *
020     * URL: http://http://www.hammurapi.biz
021     * e-Mail: support@hammurapi.biz
022     */
023    package biz.hammurapi.dispatch;
024    
025    import biz.hammurapi.util.PoliteVisitor;
026    
027    /**
028     * Dispatches visited objects to visit- and leave- dispatchers.
029     * @author Pavel Vlasov
030     * @revision $Revision$
031     */
032    public class DispatchingVisitor implements PoliteVisitor {
033    
034            private Dispatcher visitDispatcher;
035            private Dispatcher leaveDispatcher;
036    
037            /**
038             * Creates DispatchingVisitor
039             * @param visitDispatcher
040             * @param leaveDispatcher
041             */
042            public DispatchingVisitor(Dispatcher visitDispatcher, Dispatcher leaveDispatcher) {
043                    super();
044                    this.visitDispatcher=visitDispatcher;
045                    this.leaveDispatcher=leaveDispatcher;
046            }
047    
048            /**
049             * Passes argument to visit dispatcher.
050             */
051            public void leave(Object arg) {
052                    if (leaveDispatcher!=null) {
053                            leaveDispatcher.dispatch(arg);
054                    }
055            }
056    
057            /**
058             * Passes argument to leave dispatcher.
059             */
060            public boolean visit(Object arg) {
061                    if (visitDispatcher!=null) {
062                            visitDispatcher.dispatch(arg);
063                    }
064                    return true;
065            }
066    
067    }