001 /* AbstractAction.java --
002 Copyright (C) 2002, 2004, 2005, 2006 Free Software Foundation, Inc.
003
004 This file is part of GNU Classpath.
005
006 GNU Classpath is free software; you can redistribute it and/or modify
007 it under the terms of the GNU General Public License as published by
008 the Free Software Foundation; either version 2, or (at your option)
009 any later version.
010
011 GNU Classpath is distributed in the hope that it will be useful, but
012 WITHOUT ANY WARRANTY; without even the implied warranty of
013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
014 General Public License for more details.
015
016 You should have received a copy of the GNU General Public License
017 along with GNU Classpath; see the file COPYING. If not, write to the
018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019 02110-1301 USA.
020
021 Linking this library statically or dynamically with other modules is
022 making a combined work based on this library. Thus, the terms and
023 conditions of the GNU General Public License cover the whole
024 combination.
025
026 As a special exception, the copyright holders of this library give you
027 permission to link this library with independent modules to produce an
028 executable, regardless of the license terms of these independent
029 modules, and to copy and distribute the resulting executable under
030 terms of your choice, provided that you also meet, for each linked
031 independent module, the terms and conditions of the license of that
032 module. An independent module is a module which is not derived from
033 or based on this library. If you modify this library, you may extend
034 this exception to your version of the library, but you are not
035 obligated to do so. If you do not wish to do so, delete this
036 exception statement from your version. */
037
038
039 package javax.swing;
040
041 import java.beans.PropertyChangeEvent;
042 import java.beans.PropertyChangeListener;
043 import java.io.Serializable;
044 import java.util.HashMap;
045
046 import javax.swing.event.SwingPropertyChangeSupport;
047
048 /**
049 * A base class for implementing the {@link Action} interface.
050 *
051 * @author Andrew Selkirk
052 */
053 public 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 }