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 }