1/* 2 * Copyright (c) 1997, 2015, Oracle and/or its affiliates. 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. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26package javax.swing; 27 28import javax.swing.event.*; 29import java.io.Serializable; 30import java.util.EventListener; 31 32/** 33 * The abstract definition for the data model that provides 34 * a <code>List</code> with its contents. 35 * <p> 36 * <strong>Warning:</strong> 37 * Serialized objects of this class will not be compatible with 38 * future Swing releases. The current serialization support is 39 * appropriate for short term storage or RMI between applications running 40 * the same version of Swing. As of 1.4, support for long term storage 41 * of all JavaBeans™ 42 * has been added to the <code>java.beans</code> package. 43 * Please see {@link java.beans.XMLEncoder}. 44 * 45 * @param <E> the type of the elements of this model 46 * 47 * @author Hans Muller 48 * @since 1.2 49 */ 50@SuppressWarnings("serial") // Same-version serialization only 51public abstract class AbstractListModel<E> implements ListModel<E>, Serializable 52{ 53 /** 54 * The listener list. 55 */ 56 protected EventListenerList listenerList = new EventListenerList(); 57 58 59 /** 60 * Adds a listener to the list that's notified each time a change 61 * to the data model occurs. 62 * 63 * @param l the <code>ListDataListener</code> to be added 64 */ 65 public void addListDataListener(ListDataListener l) { 66 listenerList.add(ListDataListener.class, l); 67 } 68 69 70 /** 71 * Removes a listener from the list that's notified each time a 72 * change to the data model occurs. 73 * 74 * @param l the <code>ListDataListener</code> to be removed 75 */ 76 public void removeListDataListener(ListDataListener l) { 77 listenerList.remove(ListDataListener.class, l); 78 } 79 80 81 /** 82 * Returns an array of all the list data listeners 83 * registered on this <code>AbstractListModel</code>. 84 * 85 * @return all of this model's <code>ListDataListener</code>s, 86 * or an empty array if no list data listeners 87 * are currently registered 88 * 89 * @see #addListDataListener 90 * @see #removeListDataListener 91 * 92 * @since 1.4 93 */ 94 public ListDataListener[] getListDataListeners() { 95 return listenerList.getListeners(ListDataListener.class); 96 } 97 98 99 /** 100 * <code>AbstractListModel</code> subclasses must call this method 101 * <b>after</b> 102 * one or more elements of the list change. The changed elements 103 * are specified by the closed interval index0, index1 -- the endpoints 104 * are included. Note that 105 * index0 need not be less than or equal to index1. 106 * 107 * @param source the <code>ListModel</code> that changed, typically "this" 108 * @param index0 one end of the new interval 109 * @param index1 the other end of the new interval 110 * @see EventListenerList 111 * @see DefaultListModel 112 */ 113 protected void fireContentsChanged(Object source, int index0, int index1) 114 { 115 Object[] listeners = listenerList.getListenerList(); 116 ListDataEvent e = null; 117 118 for (int i = listeners.length - 2; i >= 0; i -= 2) { 119 if (listeners[i] == ListDataListener.class) { 120 if (e == null) { 121 e = new ListDataEvent(source, ListDataEvent.CONTENTS_CHANGED, index0, index1); 122 } 123 ((ListDataListener)listeners[i+1]).contentsChanged(e); 124 } 125 } 126 } 127 128 129 /** 130 * <code>AbstractListModel</code> subclasses must call this method 131 * <b>after</b> 132 * one or more elements are added to the model. The new elements 133 * are specified by a closed interval index0, index1 -- the enpoints 134 * are included. Note that 135 * index0 need not be less than or equal to index1. 136 * 137 * @param source the <code>ListModel</code> that changed, typically "this" 138 * @param index0 one end of the new interval 139 * @param index1 the other end of the new interval 140 * @see EventListenerList 141 * @see DefaultListModel 142 */ 143 protected void fireIntervalAdded(Object source, int index0, int index1) 144 { 145 Object[] listeners = listenerList.getListenerList(); 146 ListDataEvent e = null; 147 148 for (int i = listeners.length - 2; i >= 0; i -= 2) { 149 if (listeners[i] == ListDataListener.class) { 150 if (e == null) { 151 e = new ListDataEvent(source, ListDataEvent.INTERVAL_ADDED, index0, index1); 152 } 153 ((ListDataListener)listeners[i+1]).intervalAdded(e); 154 } 155 } 156 } 157 158 159 /** 160 * <code>AbstractListModel</code> subclasses must call this method 161 * <b>after</b> one or more elements are removed from the model. 162 * <code>index0</code> and <code>index1</code> are the end points 163 * of the interval that's been removed. Note that <code>index0</code> 164 * need not be less than or equal to <code>index1</code>. 165 * 166 * @param source the <code>ListModel</code> that changed, typically "this" 167 * @param index0 one end of the removed interval, 168 * including <code>index0</code> 169 * @param index1 the other end of the removed interval, 170 * including <code>index1</code> 171 * @see EventListenerList 172 * @see DefaultListModel 173 */ 174 protected void fireIntervalRemoved(Object source, int index0, int index1) 175 { 176 Object[] listeners = listenerList.getListenerList(); 177 ListDataEvent e = null; 178 179 for (int i = listeners.length - 2; i >= 0; i -= 2) { 180 if (listeners[i] == ListDataListener.class) { 181 if (e == null) { 182 e = new ListDataEvent(source, ListDataEvent.INTERVAL_REMOVED, index0, index1); 183 } 184 ((ListDataListener)listeners[i+1]).intervalRemoved(e); 185 } 186 } 187 } 188 189 /** 190 * Returns an array of all the objects currently registered as 191 * <code><em>Foo</em>Listener</code>s 192 * upon this model. 193 * <code><em>Foo</em>Listener</code>s 194 * are registered using the <code>add<em>Foo</em>Listener</code> method. 195 * <p> 196 * You can specify the <code>listenerType</code> argument 197 * with a class literal, such as <code><em>Foo</em>Listener.class</code>. 198 * For example, you can query a list model 199 * <code>m</code> 200 * for its list data listeners 201 * with the following code: 202 * 203 * <pre>ListDataListener[] ldls = (ListDataListener[])(m.getListeners(ListDataListener.class));</pre> 204 * 205 * If no such listeners exist, 206 * this method returns an empty array. 207 * 208 * @param <T> the type of {@code EventListener} class being requested 209 * @param listenerType the type of listeners requested; 210 * this parameter should specify an interface 211 * that descends from <code>java.util.EventListener</code> 212 * @return an array of all objects registered as 213 * <code><em>Foo</em>Listener</code>s 214 * on this model, 215 * or an empty array if no such 216 * listeners have been added 217 * @exception ClassCastException if <code>listenerType</code> doesn't 218 * specify a class or interface that implements 219 * <code>java.util.EventListener</code> 220 * 221 * @see #getListDataListeners 222 * 223 * @since 1.3 224 */ 225 public <T extends EventListener> T[] getListeners(Class<T> listenerType) { 226 return listenerList.getListeners(listenerType); 227 } 228} 229