001/* AbstractAction.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.beans.PropertyChangeEvent;
042import java.beans.PropertyChangeListener;
043import java.io.Serializable;
044import java.util.HashMap;
045
046import javax.swing.event.SwingPropertyChangeSupport;
047
048/**
049 * A base class for implementing the {@link Action} interface.
050 *
051 * @author Andrew Selkirk
052 */
053public abstract class AbstractAction
054  implements Action, Cloneable, Serializable
055{
056  private static final long serialVersionUID = -6803159439231523484L;
057
058  /**
059   * A flag that indicates whether or not the action is enabled.
060   */
061  protected boolean enabled = true;
062
063  /**
064   * Provides support for property change event notification.
065   */
066  protected SwingPropertyChangeSupport changeSupport =
067    new SwingPropertyChangeSupport(this);
068
069  /**
070   * store
071   */
072  private transient HashMap store = new HashMap();
073
074  /**
075   * Creates a new action with no properties set.
076   */
077  public AbstractAction()
078  {
079    // Nothing to do.
080  }
081
082  /**
083   * Creates a new action with the specified name.  The name is stored as a
084   * property with the key {@link Action#NAME}, and no other properties are
085   * initialised.
086   *
087   * @param name  the name (<code>null</code> permitted).
088   */
089  public AbstractAction(String name)
090  {
091    putValue(NAME, name);
092  }
093
094  /**
095   * Creates a new action with the specified name and icon.  The name is stored
096   * as a property with the key {@link Action#NAME}, the icon is stored as a
097   * property with the key {@link Action#SMALL_ICON}, and no other properties
098   * are initialised.
099   *
100   * @param name  the name (<code>null</code> permitted).
101   * @param icon  the icon (<code>null</code> permitted).
102   */
103  public AbstractAction(String name, Icon icon)
104  {
105    putValue(NAME, name);
106    putValue(SMALL_ICON, icon);
107  }
108
109  /**
110   * Returns a clone of the action.
111   *
112   * @return A clone of the action.
113   *
114   * @exception CloneNotSupportedException if there is a problem cloning the
115   *            action.
116   */
117  protected Object clone() throws CloneNotSupportedException
118  {
119    AbstractAction copy = (AbstractAction) super.clone();
120    copy.store = (HashMap) store.clone();
121    return copy;
122  }
123
124  /**
125   * Returns the value associated with the specified key.
126   *
127   * @param key  the key (not <code>null</code>).
128   *
129   * @return The value associated with the specified key, or
130   *         <code>null</code> if the key is not found.
131   *
132   * @see #putValue(String, Object)
133   */
134  public Object getValue(String key)
135  {
136    return store.get(key);
137  }
138
139  /**
140   * Sets the value associated with the specified key and sends a
141   * {@link java.beans.PropertyChangeEvent} to all registered listeners.
142   * The standard keys are:
143   * <ul>
144   * <li>{@link #NAME}</li>
145   * <li>{@link #SHORT_DESCRIPTION}</li>
146   * <li>{@link #LONG_DESCRIPTION}</li>
147   * <li>{@link #SMALL_ICON}</li>
148   * <li>{@link #ACTION_COMMAND_KEY}</li>
149   * <li>{@link #ACCELERATOR_KEY}</li>
150   * <li>{@link #MNEMONIC_KEY}</li>
151   * </ul>
152   * Any existing value associated with the key will be overwritten.
153   *
154   * @param key  the key (not <code>null</code>).
155   * @param value  the value (<code>null</code> permitted).
156   */
157  public void putValue(String key, Object value)
158  {
159    Object old = getValue(key);
160    if ((old == null && value != null) || (old != null && !old.equals(value)))
161    {
162      store.put(key, value);
163      firePropertyChange(key, old, value);
164    }
165  }
166
167  /**
168   * Returns the flag that indicates whether or not the action is enabled.
169   *
170   * @return The flag.
171   *
172   * @see #setEnabled(boolean)
173   */
174  public boolean isEnabled()
175  {
176    return enabled;
177  }
178
179  /**
180   * Sets the flag that indicates whether or not the action is enabled and, if
181   * the value of the flag changed from the previous setting, sends a
182   * {@link java.beans.PropertyChangeEvent} to all registered listeners (using
183   * the property name 'enabled').
184   *
185   * @param enabled  the new flag value.
186   *
187   * @see #isEnabled()
188   */
189  public void setEnabled(boolean enabled)
190  {
191    if (enabled != this.enabled)
192    {
193      this.enabled = enabled;
194      firePropertyChange("enabled", !this.enabled, this.enabled);
195    }
196  }
197
198  /**
199   * Returns an array of the keys for the property values that have been
200   * defined via the {@link #putValue(String, Object)} method (or the class
201   * constructor).
202   *
203   * @return An array of keys.
204   */
205  public Object[] getKeys()
206  {
207    return store.keySet().toArray();
208  }
209
210  /**
211   * Sends a {@link PropertyChangeEvent} for the named property to all
212   * registered listeners.
213   *
214   * @param propertyName  the property name.
215   * @param oldValue  the old value of the property.
216   * @param newValue  the new value of the property.
217   */
218  protected void firePropertyChange(String propertyName, Object oldValue,
219                                    Object newValue)
220  {
221    changeSupport.firePropertyChange(propertyName, oldValue, newValue);
222  }
223
224  /**
225   * Sends a {@link PropertyChangeEvent} for the named property to all
226   * registered listeners.  This private method is called by the
227   * {@link #setEnabled(boolean)} method.
228   *
229   * @param propertyName  the property name.
230   * @param oldValue  the old value of the property.
231   * @param newValue  the new value of the property.
232   */
233  private void firePropertyChange(String propertyName, boolean oldValue,
234                                  boolean newValue)
235  {
236    changeSupport.firePropertyChange(propertyName, oldValue, newValue);
237  }
238
239  /**
240   * Registers a listener to receive {@link PropertyChangeEvent} notifications
241   * from this action.
242   *
243   * @param listener the listener.
244   *
245   * @see #removePropertyChangeListener(PropertyChangeListener)
246   */
247  public void addPropertyChangeListener(PropertyChangeListener listener)
248  {
249    changeSupport.addPropertyChangeListener(listener);
250  }
251
252  /**
253   * Deregisters a listener so that it no longer receives
254   * {@link PropertyChangeEvent} notifications from this action.
255   *
256   * @param listener the listener.
257   *
258   * @see #addPropertyChangeListener(PropertyChangeListener)
259   */
260  public void removePropertyChangeListener(PropertyChangeListener listener)
261  {
262    changeSupport.removePropertyChangeListener(listener);
263  }
264
265  /**
266   * Returns all registered listeners.
267   *
268   * @return An array of listeners.
269   *
270   * @since 1.4
271   */
272  public PropertyChangeListener[] getPropertyChangeListeners()
273  {
274    return changeSupport.getPropertyChangeListeners();
275  }
276}