001 /*
002 * This file is part of the Echo Point Project. This project is a collection
003 * of Components that have extended the Echo Web Application Framework.
004 *
005 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
006 *
007 * The contents of this file are subject to the Mozilla Public License Version
008 * 1.1 (the "License"); you may not use this file except in compliance with
009 * the License. You may obtain a copy of the License at
010 * http://www.mozilla.org/MPL/
011 *
012 * Software distributed under the License is distributed on an "AS IS" basis,
013 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
014 * for the specific language governing rights and limitations under the
015 * License.
016 *
017 * Alternatively, the contents of this file may be used under the terms of
018 * either the GNU General Public License Version 2 or later (the "GPL"), or
019 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
020 * in which case the provisions of the GPL or the LGPL are applicable instead
021 * of those above. If you wish to allow use of your version of this file only
022 * under the terms of either the GPL or the LGPL, and not to allow others to
023 * use your version of this file under the terms of the MPL, indicate your
024 * decision by deleting the provisions above and replace them with the notice
025 * and other provisions required by the GPL or the LGPL. If you do not delete
026 * the provisions above, a recipient may use your version of this file under
027 * the terms of any one of the MPL, the GPL or the LGPL.
028 */
029 package echopoint.util;
030
031 import java.io.Serializable;
032 import java.util.HashMap;
033 import java.util.Iterator;
034 import java.util.Map;
035
036 import nextapp.echo.app.Component;
037
038 /**
039 * <code>ComponentTracker</code> keeps track of components that have been
040 * added and removed from it and its associated component. This class allows
041 * you to add/remove child components while keeping them in a known
042 * bucket (the tracker).
043 */
044
045 public class ComponentTracker implements Serializable {
046 Map componentMap;
047 Component trackee;
048
049 /**
050 * Constructs a <code>ComponentTracker</code> that will keep track
051 * of components on behalf of <code>trackeeComponent</code>
052 *
053 * @param trackeeComponent - the component for which child components
054 * will be tracked.
055 */
056 public ComponentTracker(Component trackeeComponent) {
057 this.trackee = trackeeComponent;
058 }
059
060 /**
061 * @see Component#add(Component)
062 */
063 public void add(Component child) {
064 add(child,-1);
065 }
066
067 /**
068 * @see Component#add(Component, int)
069 */
070 public void add(Component child, int index) {
071 if (componentMap == null)
072 componentMap = new HashMap();
073 componentMap.put(child,child);
074 trackee.add(child,index);
075 }
076
077 /**
078 * @see Component#remove(Component)
079 */
080 public void remove(Component child) {
081 if (componentMap != null) {
082 componentMap.remove(child);
083 }
084 trackee.remove(child);
085 }
086
087 /**
088 * @see Component#remove(int)
089 */
090 public void remove(int index) {
091 Component child = trackee.getComponent(index);
092 if (componentMap != null) {
093 componentMap.remove(child);
094 }
095 trackee.remove(index);
096 }
097
098 /**
099 * @see Component#removeAll()
100 */
101 public void removeAll() {
102 if (componentMap != null) {
103 for (Iterator iter = componentMap.keySet().iterator(); iter.hasNext();) {
104 Component child = (Component) iter.next();
105 trackee.remove(child);
106 iter.remove();
107 }
108 }
109 }
110
111 /**
112 * @see Component#getComponents()
113 */
114 public Component[] getComponents() {
115 if (componentMap == null) {
116 return new Component[0];
117 }
118 Component children[] = new Component[componentMap.size()];
119 int i = 0;
120 for (Iterator iter = componentMap.keySet().iterator(); iter.hasNext(); i++) {
121 Component child = (Component) iter.next();
122 children[i] = child;
123 }
124 return children;
125 }
126
127 /**
128 * @see Component#getComponentCount()
129 */
130 public int getComponentCount() {
131 if (componentMap == null) {
132 return 0;
133 }
134 return componentMap.size();
135 }
136
137
138 }