001/**
002 *   GRANITE DATA SERVICES
003 *   Copyright (C) 2006-2013 GRANITE DATA SERVICES S.A.S.
004 *
005 *   This file is part of the Granite Data Services Platform.
006 *
007 *                               ***
008 *
009 *   Community License: GPL 3.0
010 *
011 *   This file is free software: you can redistribute it and/or modify
012 *   it under the terms of the GNU General Public License as published
013 *   by the Free Software Foundation, either version 3 of the License,
014 *   or (at your option) any later version.
015 *
016 *   This file is distributed in the hope that it will be useful, but
017 *   WITHOUT ANY WARRANTY; without even the implied warranty of
018 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
019 *   GNU General Public License for more details.
020 *
021 *   You should have received a copy of the GNU General Public License
022 *   along with this program. If not, see <http://www.gnu.org/licenses/>.
023 *
024 *                               ***
025 *
026 *   Available Commercial License: GraniteDS SLA 1.0
027 *
028 *   This is the appropriate option if you are creating proprietary
029 *   applications and you are not prepared to distribute and share the
030 *   source code of your application under the GPL v3 license.
031 *
032 *   Please visit http://www.granitedataservices.com/license for more
033 *   details.
034 */
035package org.granite.client.collection;
036
037import org.granite.client.collection.CollectionChangeEvent.Kind;
038
039/**
040 * @author William DRAI
041 */
042public class CollectionChangeSupport {
043
044        private final Object collection;
045        private CollectionChangeListener[] listeners = null;
046        
047        public CollectionChangeSupport(Object collection) {
048                this.collection = collection;
049        }
050        
051        public void addCollectionChangeListener(CollectionChangeListener listener) {
052                if (listeners == null)
053                        listeners = new CollectionChangeListener[] { listener };
054                else {
055                        CollectionChangeListener[] newListeners = new CollectionChangeListener[listeners.length+1];
056                        System.arraycopy(listeners, 0, newListeners, 0, listeners.length);
057                        newListeners[listeners.length] = listener;
058                        listeners = newListeners;
059                }
060        }
061        
062        public void fireCollectionChangeEvent(Kind kind, Object key, Object[] values) {
063                if (listeners == null)
064                        return;
065                CollectionChangeEvent event = new CollectionChangeEvent(collection, kind, key, values);
066                for (CollectionChangeListener listener : listeners)
067                        listener.collectionChange(event);
068        }
069        
070        public void removeCollectionChangeListener(CollectionChangeListener listener) {
071                if (listeners == null)
072                        return;
073                if (listeners.length == 1) {
074                        if (listeners[0] == listener)
075                                listeners = null;
076                }
077                else {
078                        int index = -1;
079                        for (int i = 0; i < listeners.length; i++) {
080                                if (listeners[i] == listener) {
081                                        index = i;
082                                        break;
083                                }
084                        }
085                        if (index >= 0) {
086                                CollectionChangeListener[] newListeners = new CollectionChangeListener[listeners.length-1];
087                                if (index > 0)
088                                        System.arraycopy(listeners, 0, newListeners, 0, index);
089                                if (index < listeners.length-1)
090                                        System.arraycopy(listeners, index+1, newListeners, index, listeners.length-index-1);
091                                listeners = newListeners;
092                        }
093                }
094        }
095}