Source for javax.swing.AbstractAction

   1: /* AbstractAction.java --
   2:    Copyright (C) 2002, 2004, 2005, 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.beans.PropertyChangeEvent;
  42: import java.beans.PropertyChangeListener;
  43: import java.io.Serializable;
  44: import java.util.HashMap;
  45: 
  46: import javax.swing.event.SwingPropertyChangeSupport;
  47: 
  48: /**
  49:  * A base class for implementing the {@link Action} interface.
  50:  * 
  51:  * @author Andrew Selkirk
  52:  */
  53: public abstract class AbstractAction
  54:   implements Action, Cloneable, Serializable
  55: {
  56:   private static final long serialVersionUID = -6803159439231523484L;
  57: 
  58:   /**
  59:    * A flag that indicates whether or not the action is enabled.
  60:    */
  61:   protected boolean enabled = true;
  62:   
  63:   /**
  64:    * Provides support for property change event notification. 
  65:    */
  66:   protected SwingPropertyChangeSupport changeSupport =
  67:     new SwingPropertyChangeSupport(this);
  68: 
  69:   /**
  70:    * store
  71:    */
  72:   private transient HashMap store = new HashMap();
  73: 
  74:   /**
  75:    * Creates a new action with no properties set.
  76:    */
  77:   public AbstractAction()
  78:   {
  79:     // Nothing to do.
  80:   }
  81: 
  82:   /**
  83:    * Creates a new action with the specified name.  The name is stored as a 
  84:    * property with the key {@link Action#NAME}, and no other properties are
  85:    * initialised.
  86:    *
  87:    * @param name  the name (<code>null</code> permitted).
  88:    */
  89:   public AbstractAction(String name)
  90:   {
  91:     putValue(NAME, name);
  92:   }
  93: 
  94:   /**
  95:    * Creates a new action with the specified name and icon.  The name is stored
  96:    * as a property with the key {@link Action#NAME}, the icon is stored as a
  97:    * property with the key {@link Action#SMALL_ICON}, and no other properties 
  98:    * are initialised.
  99:    *
 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: }