001/* AbstractCellEditor.java --
002   Copyright (C) 2002, 2004, 2005, 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.EventObject;
043
044import javax.swing.event.CellEditorListener;
045import javax.swing.event.ChangeEvent;
046import javax.swing.event.EventListenerList;
047
048/**
049 * An abstract superclass for table and tree cell editors. This provides some
050 * common shared functionality.
051 *
052 * @author Andrew Selkirk
053 */
054public abstract class AbstractCellEditor
055  implements CellEditor, Serializable
056{
057  private static final long serialVersionUID = -1048006551406220959L;
058
059  /**
060   * Our Swing event listeners.
061   */
062  protected EventListenerList listenerList;
063
064  /**
065   * The cached ChangeEvent.
066   */
067  protected transient ChangeEvent changeEvent;
068
069  /**
070   * Creates a new instance of AbstractCellEditor.
071   */
072  public AbstractCellEditor()
073  {
074    listenerList = new EventListenerList();
075    changeEvent = new ChangeEvent(this);
076  }
077
078  /**
079   * Returns <code>true</code> if the cell is editable using
080   * <code>event</code>, <code>false</code>
081   * if it's not. The default behaviour is to return <code>true</code>.
082   *
083   * @param event an event
084   *
085   * @return <code>true</code> if the cell is editable using
086   *     <code>event</code>, <code>false</code> if it's not
087   */
088  public boolean isCellEditable(EventObject event)
089  {
090    return true;
091  }
092
093  /**
094   * Returns <code>true</code> if the editing cell should be selected,
095   * <code>false</code> otherwise. This is usually returning <code>true</code>,
096   * but in some special cases it might be useful not to switch cell selection
097   * when editing one cell.
098   *
099   * @param event an event
100   *
101   * @return <code>true</code> if the editing cell should be selected,
102   *     <code>false</code> otherwise
103   */
104  public boolean shouldSelectCell(EventObject event)
105  {
106    return true;
107  }
108
109  /**
110   * Stop editing the cell and accept any partial value that has been entered
111   * into the cell.
112   *
113   * @return <code>true</code> if editing has been stopped successfully,
114   *     <code>false</code>otherwise
115   */
116  public boolean stopCellEditing()
117  {
118    fireEditingStopped();
119    return true;
120  }
121
122  /**
123   * Stop editing the cell and do not accept any partial value that has
124   * been entered into the cell.
125   */
126  public void cancelCellEditing()
127  {
128    fireEditingCanceled();
129  }
130
131  /**
132   * Adds a CellEditorListener to the list of CellEditorListeners of this
133   * CellEditor.
134   *
135   * @param listener the CellEditorListener to add
136   */
137  public void addCellEditorListener(CellEditorListener listener)
138  {
139    listenerList.add(CellEditorListener.class, listener);
140  }
141
142  /**
143   * Removes the specified CellEditorListener from the list of the
144   * CellEditorListeners of this CellEditor.
145   *
146   * @param listener the CellEditorListener to remove
147   */
148  public void removeCellEditorListener(CellEditorListener listener)
149  {
150    listenerList.remove(CellEditorListener.class, listener);
151  }
152
153  /**
154   * Returns the list of CellEditorListeners that have been registered
155   * in this CellEditor.
156   *
157   * @return the list of CellEditorListeners that have been registered
158   *     in this CellEditor
159   *
160   * @since 1.4
161   */
162  public CellEditorListener[] getCellEditorListeners()
163  {
164    return (CellEditorListener[]) listenerList.getListeners(
165        CellEditorListener.class);
166  }
167
168  /**
169   * Notifies all registered listeners that the editing of the cell has has been
170   * stopped.
171   */
172  protected void fireEditingStopped()
173  {
174    CellEditorListener[] listeners = getCellEditorListeners();
175
176    for (int index = 0; index < listeners.length; index++)
177      {
178        listeners[index].editingStopped(changeEvent);
179      }
180  }
181
182  /**
183   * Notifies all registered listeners that the editing of the cell has
184   * has been canceled.
185   */
186  protected void fireEditingCanceled()
187  {
188    CellEditorListener[] listeners = getCellEditorListeners();
189
190    for (int index = 0; index < listeners.length; index++)
191      {
192        listeners[index].editingCanceled(changeEvent);
193      }
194  }
195}