libjava/classpath/javax/swing/AbstractListModel.java

   1 /* AbstractListModel.java --
   2    Copyright (C) 2002, 2004, 2006, Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19 02110-1301 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38
  39 package javax.swing;
  40
  41 import java.io.Serializable;
  42 import java.util.EventListener;
  43
  44 import javax.swing.event.EventListenerList;
  45 import javax.swing.event.ListDataEvent;
  46 import javax.swing.event.ListDataListener;
  47
  48 /**
  49  * Provides standard implementations of some methods in {@link ListModel}.
  50  *
  51  * @author Ronald Veldema
  52  * @author Andrew Selkirk
  53  */
  54 public abstract class AbstractListModel implements ListModel, Serializable
  55 {
  56   private static final long serialVersionUID = -3285184064379168730L;
  57
  58   /** List of ListDataListeners called for each change to the list. */
  59   protected EventListenerList listenerList;
  60
  61   /**
  62    * Creates a new model instance - initialises the event listener list.
  63    */
  64   public AbstractListModel()
  65   {
  66     listenerList = new EventListenerList();
  67   }
  68
  69   /**
  70    * Add a listener object to this model. The listener will be called
  71    * any time the set of elements in the model is changed.
  72    *
  73    * @param listener The listener to add
  74    */
  75   public void addListDataListener(ListDataListener listener)
  76   {
  77     listenerList.add(ListDataListener.class, listener);
  78   }
  79
  80   /**
  81    * Add a listener object to this model. The listener will no longer be
  82    * called when the set of elements in the model is changed.
  83    *
  84    * @param listener The listener to remove
  85    */
  86   public void removeListDataListener(ListDataListener listener)
  87   {
  88     listenerList.remove(ListDataListener.class, listener);
  89   }
  90
  91   /**
  92    * Call {@link ListDataListener#contentsChanged} on each element of the
  93    * {@link #listenerList} which is a {@link ListDataListener}. The event
  94    * fired has type {@link ListDataEvent#CONTENTS_CHANGED} and represents a
  95    * change to the data elements in the range [startIndex, endIndex]
  96    * inclusive.
  97    *
  98    * @param source The source of the change, typically <code>this</code>
  99    * @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 EventListener[] getListeners(Class 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 }