001 /* AbstractSpinnerModel.java --
002 Copyright (C) 2004, 2006, Free Software Foundation, Inc.
003
004 This file is part of GNU Classpath.
005
006 GNU Classpath is free software; you can redistribute it and/or modify
007 it under the terms of the GNU General Public License as published by
008 the Free Software Foundation; either version 2, or (at your option)
009 any later version.
010
011 GNU Classpath is distributed in the hope that it will be useful, but
012 WITHOUT ANY WARRANTY; without even the implied warranty of
013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
014 General Public License for more details.
015
016 You should have received a copy of the GNU General Public License
017 along with GNU Classpath; see the file COPYING. If not, write to the
018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019 02110-1301 USA.
020
021 Linking this library statically or dynamically with other modules is
022 making a combined work based on this library. Thus, the terms and
023 conditions of the GNU General Public License cover the whole
024 combination.
025
026 As a special exception, the copyright holders of this library give you
027 permission to link this library with independent modules to produce an
028 executable, regardless of the license terms of these independent
029 modules, and to copy and distribute the resulting executable under
030 terms of your choice, provided that you also meet, for each linked
031 independent module, the terms and conditions of the license of that
032 module. An independent module is a module which is not derived from
033 or based on this library. If you modify this library, you may extend
034 this exception to your version of the library, but you are not
035 obligated to do so. If you do not wish to do so, delete this
036 exception statement from your version. */
037
038
039 package javax.swing;
040
041 import java.util.EventListener;
042
043 import javax.swing.event.ChangeEvent;
044 import javax.swing.event.ChangeListener;
045 import javax.swing.event.EventListenerList;
046
047 /**
048 * Provides standard implementations for some of the methods in
049 * {@link SpinnerModel}.
050 *
051 * @since 1.4
052 *
053 * @author Ka-Hing Cheung
054 */
055 public abstract class AbstractSpinnerModel implements SpinnerModel
056 {
057 private ChangeEvent changeEvent = new ChangeEvent(this);
058
059 /** Stores the listeners registered with the model. */
060 protected EventListenerList listenerList = new EventListenerList();
061
062 /**
063 * Creates an <code>AbstractSpinnerModel</code>.
064 */
065 public AbstractSpinnerModel()
066 {
067 // Nothing to do here.
068 }
069
070 /**
071 * Registers a <code>ChangeListener</code> with the model so that it will
072 * receive {@link ChangeEvent} notifications when the model changes.
073 *
074 * @param listener the listener to add (<code>null</code> is ignored).
075 */
076 public void addChangeListener(ChangeListener listener)
077 {
078 listenerList.add(ChangeListener.class, listener);
079 }
080
081 /**
082 * Gets all the listeners that are of a particular type.
083 *
084 * @param c the type of listener
085 * @return the listeners that are of the specific type
086 */
087 public <T extends EventListener> T[] getListeners(Class<T> c)
088 {
089 return listenerList.getListeners(c);
090 }
091
092 /**
093 * Gets all the <code>ChangeListener</code>s.
094 *
095 * @return all the <code>ChangeListener</code>s
096 */
097 public ChangeListener[] getChangeListeners()
098 {
099 return (ChangeListener[]) listenerList.getListeners(ChangeListener.class);
100 }
101
102 /**
103 * Remove a particular listener.
104 *
105 * @param listener the listener to remove
106 */
107 public void removeChangeListener(ChangeListener listener)
108 {
109 listenerList.remove(ChangeListener.class, listener);
110 }
111
112 /**
113 * Fires a <code>ChangeEvent</code> to all the <code>ChangeListener</code>s
114 * added to this model
115 */
116 protected void fireStateChanged()
117 {
118 ChangeListener[] listeners = getChangeListeners();
119
120 for (int i = 0; i < listeners.length; ++i)
121 listeners[i].stateChanged(changeEvent);
122 }
123 }