001/* AbstractListModel.java --
002   Copyright (C) 2002, 2004, 2006, Free Software Foundation, Inc.
003
004This file is part of GNU Classpath.
005
006GNU Classpath is free software; you can redistribute it and/or modify
007it under the terms of the GNU General Public License as published by
008the Free Software Foundation; either version 2, or (at your option)
009any later version.
010
011GNU Classpath is distributed in the hope that it will be useful, but
012WITHOUT ANY WARRANTY; without even the implied warranty of
013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014General Public License for more details.
015
016You should have received a copy of the GNU General Public License
017along with GNU Classpath; see the file COPYING.  If not, write to the
018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
01902110-1301 USA.
020
021Linking this library statically or dynamically with other modules is
022making a combined work based on this library.  Thus, the terms and
023conditions of the GNU General Public License cover the whole
024combination.
025
026As a special exception, the copyright holders of this library give you
027permission to link this library with independent modules to produce an
028executable, regardless of the license terms of these independent
029modules, and to copy and distribute the resulting executable under
030terms of your choice, provided that you also meet, for each linked
031independent module, the terms and conditions of the license of that
032module.  An independent module is a module which is not derived from
033or based on this library.  If you modify this library, you may extend
034this exception to your version of the library, but you are not
035obligated to do so.  If you do not wish to do so, delete this
036exception statement from your version. */
037
038
039package javax.swing;
040
041import java.io.Serializable;
042import java.util.EventListener;
043
044import javax.swing.event.EventListenerList;
045import javax.swing.event.ListDataEvent;
046import javax.swing.event.ListDataListener;
047
048/**
049 * Provides standard implementations of some methods in {@link ListModel}.
050 *
051 * @author Ronald Veldema
052 * @author Andrew Selkirk
053 */
054public abstract class AbstractListModel implements ListModel, Serializable
055{
056  private static final long serialVersionUID = -3285184064379168730L;
057
058  /** List of ListDataListeners called for each change to the list. */
059  protected EventListenerList listenerList;
060
061  /**
062   * Creates a new model instance - initialises the event listener list.
063   */
064  public AbstractListModel()
065  {
066    listenerList = new EventListenerList();
067  }
068
069  /**
070   * Add a listener object to this model. The listener will be called
071   * any time the set of elements in the model is changed.
072   *
073   * @param listener The listener to add
074   */
075  public void addListDataListener(ListDataListener listener)
076  {
077    listenerList.add(ListDataListener.class, listener);
078  }
079
080  /**
081   * Add a listener object to this model. The listener will no longer be
082   * called when the set of elements in the model is changed.
083   *
084   * @param listener The listener to remove
085   */
086  public void removeListDataListener(ListDataListener listener)
087  {
088    listenerList.remove(ListDataListener.class, listener);
089  }
090
091  /**
092   * Call {@link ListDataListener#contentsChanged} on each element of the
093   * {@link #listenerList} which is a {@link ListDataListener}. The event
094   * fired has type {@link ListDataEvent#CONTENTS_CHANGED} and represents a
095   * change to the data elements in the range [startIndex, endIndex]
096   * inclusive.
097   *
098   * @param source The source of the change, typically <code>this</code>
099   * @param startIndex The index of the first element which changed
100   * @param endIndex The index of the last element which changed
101   */
102  protected void fireContentsChanged(Object source, int startIndex,
103                                     int endIndex)
104  {
105    ListDataEvent event = new ListDataEvent(source, ListDataEvent.CONTENTS_CHANGED,
106                                            startIndex, endIndex);
107    ListDataListener[] listeners = getListDataListeners();
108
109    for (int index = 0; index < listeners.length; index++)
110      listeners[index].contentsChanged(event);
111  }
112
113  /**
114   * Call {@link ListDataListener#intervalAdded} on each element of the
115   * {@link #listenerList} which is a {@link ListDataListener}. The event
116   * fired has type {@link ListDataEvent#INTERVAL_ADDED} and represents an
117   * addition of the data elements in the range [startIndex, endIndex]
118   * inclusive.
119   *
120   * @param source The source of the change, typically <code>this</code>
121   * @param startIndex The index of the first new element
122   * @param endIndex The index of the last new element
123   */
124  protected void fireIntervalAdded(Object source, int startIndex, int endIndex)
125  {
126    ListDataEvent event =
127      new ListDataEvent(source, ListDataEvent.INTERVAL_ADDED,
128                        startIndex, endIndex);
129    ListDataListener[] listeners = getListDataListeners();
130
131    for (int index = 0; index < listeners.length; index++)
132      listeners[index].intervalAdded(event);
133  }
134
135  /**
136   * Call {@link ListDataListener#intervalRemoved} on each element of the
137   * {@link #listenerList} which is a {@link ListDataListener}. The event
138   * fired has type {@link ListDataEvent#INTERVAL_REMOVED} and represents a
139   * removal of the data elements in the range [startIndex, endIndex]
140   * inclusive.
141   *
142   * @param source The source of the change, typically <code>this</code>
143   * @param startIndex The index of the first element removed
144   * @param endIndex The index of the last element removed
145   */
146  protected void fireIntervalRemoved(Object source, int startIndex,
147                                     int endIndex)
148  {
149    ListDataEvent event =
150      new ListDataEvent(source, ListDataEvent.INTERVAL_REMOVED,
151                        startIndex, endIndex);
152    ListDataListener[] listeners = getListDataListeners();
153
154    for (int index = 0; index < listeners.length; index++)
155      listeners[index].intervalRemoved(event);
156  }
157
158  /**
159   * Return the subset of {@link EventListener} objects found in this
160   * object's {@link #listenerList} which are elements of the specified
161   * type.
162   *
163   * @param listenerType The type of listeners to select
164   *
165   * @return The set of listeners of the specified type
166   */
167  public <T extends EventListener> T[] getListeners(Class<T> listenerType)
168  {
169    return listenerList.getListeners(listenerType);
170  }
171
172  /**
173   * A synonym for <code>getListeners(ListDataListener.class)</code>.
174   *
175   * @return The set of ListDataListeners found in the {@link #listenerList}
176   */
177  public ListDataListener[] getListDataListeners()
178  {
179    return (ListDataListener[]) getListeners(ListDataListener.class);
180  }
181}