J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1997-2004 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package javax.swing; |
| 27 | |
| 28 | import javax.swing.event.*; |
| 29 | import java.io.Serializable; |
| 30 | import java.util.EventListener; |
| 31 | |
| 32 | /** |
| 33 | * A generic implementation of SingleSelectionModel. |
| 34 | * <p> |
| 35 | * <strong>Warning:</strong> |
| 36 | * Serialized objects of this class will not be compatible with |
| 37 | * future Swing releases. The current serialization support is |
| 38 | * appropriate for short term storage or RMI between applications running |
| 39 | * the same version of Swing. As of 1.4, support for long term storage |
| 40 | * of all JavaBeans<sup><font size="-2">TM</font></sup> |
| 41 | * has been added to the <code>java.beans</code> package. |
| 42 | * Please see {@link java.beans.XMLEncoder}. |
| 43 | * |
| 44 | * @author Dave Moore |
| 45 | */ |
| 46 | public class DefaultSingleSelectionModel implements SingleSelectionModel, |
| 47 | Serializable { |
| 48 | /* Only one ModelChangeEvent is needed per model instance since the |
| 49 | * event's only (read-only) state is the source property. The source |
| 50 | * of events generated here is always "this". |
| 51 | */ |
| 52 | protected transient ChangeEvent changeEvent = null; |
| 53 | /** The collection of registered listeners */ |
| 54 | protected EventListenerList listenerList = new EventListenerList(); |
| 55 | |
| 56 | private int index = -1; |
| 57 | |
| 58 | // implements javax.swing.SingleSelectionModel |
| 59 | public int getSelectedIndex() { |
| 60 | return index; |
| 61 | } |
| 62 | |
| 63 | // implements javax.swing.SingleSelectionModel |
| 64 | public void setSelectedIndex(int index) { |
| 65 | if (this.index != index) { |
| 66 | this.index = index; |
| 67 | fireStateChanged(); |
| 68 | } |
| 69 | } |
| 70 | |
| 71 | // implements javax.swing.SingleSelectionModel |
| 72 | public void clearSelection() { |
| 73 | setSelectedIndex(-1); |
| 74 | } |
| 75 | |
| 76 | // implements javax.swing.SingleSelectionModel |
| 77 | public boolean isSelected() { |
| 78 | boolean ret = false; |
| 79 | if (getSelectedIndex() != -1) { |
| 80 | ret = true; |
| 81 | } |
| 82 | return ret; |
| 83 | } |
| 84 | |
| 85 | /** |
| 86 | * Adds a <code>ChangeListener</code> to the button. |
| 87 | */ |
| 88 | public void addChangeListener(ChangeListener l) { |
| 89 | listenerList.add(ChangeListener.class, l); |
| 90 | } |
| 91 | |
| 92 | /** |
| 93 | * Removes a <code>ChangeListener</code> from the button. |
| 94 | */ |
| 95 | public void removeChangeListener(ChangeListener l) { |
| 96 | listenerList.remove(ChangeListener.class, l); |
| 97 | } |
| 98 | |
| 99 | /** |
| 100 | * Returns an array of all the change listeners |
| 101 | * registered on this <code>DefaultSingleSelectionModel</code>. |
| 102 | * |
| 103 | * @return all of this model's <code>ChangeListener</code>s |
| 104 | * or an empty |
| 105 | * array if no change listeners are currently registered |
| 106 | * |
| 107 | * @see #addChangeListener |
| 108 | * @see #removeChangeListener |
| 109 | * |
| 110 | * @since 1.4 |
| 111 | */ |
| 112 | public ChangeListener[] getChangeListeners() { |
| 113 | return (ChangeListener[])listenerList.getListeners( |
| 114 | ChangeListener.class); |
| 115 | } |
| 116 | |
| 117 | /** |
| 118 | * Notifies all listeners that have registered interest for |
| 119 | * notification on this event type. The event instance |
| 120 | * is created lazily. |
| 121 | * @see EventListenerList |
| 122 | */ |
| 123 | protected void fireStateChanged() { |
| 124 | // Guaranteed to return a non-null array |
| 125 | Object[] listeners = listenerList.getListenerList(); |
| 126 | // Process the listeners last to first, notifying |
| 127 | // those that are interested in this event |
| 128 | for (int i = listeners.length-2; i>=0; i-=2) { |
| 129 | if (listeners[i]==ChangeListener.class) { |
| 130 | // Lazily create the event: |
| 131 | if (changeEvent == null) |
| 132 | changeEvent = new ChangeEvent(this); |
| 133 | ((ChangeListener)listeners[i+1]).stateChanged(changeEvent); |
| 134 | } |
| 135 | } |
| 136 | } |
| 137 | |
| 138 | /** |
| 139 | * Returns an array of all the objects currently registered as |
| 140 | * <code><em>Foo</em>Listener</code>s |
| 141 | * upon this model. |
| 142 | * <code><em>Foo</em>Listener</code>s |
| 143 | * are registered using the <code>add<em>Foo</em>Listener</code> method. |
| 144 | * <p> |
| 145 | * You can specify the <code>listenerType</code> argument |
| 146 | * with a class literal, such as <code><em>Foo</em>Listener.class</code>. |
| 147 | * For example, you can query a <code>DefaultSingleSelectionModel</code> |
| 148 | * instance <code>m</code> |
| 149 | * for its change listeners |
| 150 | * with the following code: |
| 151 | * |
| 152 | * <pre>ChangeListener[] cls = (ChangeListener[])(m.getListeners(ChangeListener.class));</pre> |
| 153 | * |
| 154 | * If no such listeners exist, |
| 155 | * this method returns an empty array. |
| 156 | * |
| 157 | * @param listenerType the type of listeners requested; |
| 158 | * this parameter should specify an interface |
| 159 | * that descends from <code>java.util.EventListener</code> |
| 160 | * @return an array of all objects registered as |
| 161 | * <code><em>Foo</em>Listener</code>s |
| 162 | * on this model, |
| 163 | * or an empty array if no such |
| 164 | * listeners have been added |
| 165 | * @exception ClassCastException if <code>listenerType</code> doesn't |
| 166 | * specify a class or interface that implements |
| 167 | * <code>java.util.EventListener</code> |
| 168 | * |
| 169 | * @see #getChangeListeners |
| 170 | * |
| 171 | * @since 1.3 |
| 172 | */ |
| 173 | public <T extends EventListener> T[] getListeners(Class<T> listenerType) { |
| 174 | return listenerList.getListeners(listenerType); |
| 175 | } |
| 176 | } |