libjava/classpath/java/awt/MenuItem.java

   1 /* MenuItem.java -- An item in a menu
   2    Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004 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 java.awt;
  40
  41 import java.awt.event.ActionEvent;
  42 import java.awt.event.ActionListener;
  43 import java.awt.peer.MenuItemPeer;
  44 import java.io.Serializable;
  45 import java.lang.reflect.Array;
  46 import java.util.EventListener;
  47
  48 import javax.accessibility.Accessible;
  49 import javax.accessibility.AccessibleAction;
  50 import javax.accessibility.AccessibleContext;
  51 import javax.accessibility.AccessibleRole;
  52 import javax.accessibility.AccessibleValue;
  53
  54 /**
  55   * This class represents an item in a menu.
  56   *
  57   * @author Aaron M. Renn (arenn@urbanophile.com)
  58   */
  59 public class MenuItem extends MenuComponent
  60   implements Serializable, Accessible
  61 {
  62
  63 /*
  64  * Static Variables
  65  */
  66
  67 // Serialization Constant
  68 private static final long serialVersionUID = -21757335363267194L;
  69
  70 /*************************************************************************/
  71
  72 /*
  73  * Instance Variables
  74  */
  75
  76 /**
  77   * @serial The name of the action command generated by this item.
  78   * This is package-private to avoid an accessor method.
  79   */
  80 String actionCommand;
  81
  82 /**
  83   * @serial Indicates whether or not this menu item is enabled.
  84   * This is package-private to avoid an accessor method.
  85   */
  86 boolean enabled = true;
  87
  88 /**
  89   * @serial The mask of events that are enabled for this menu item.
  90   */
  91 long eventMask;
  92
  93 /**
  94   * @serial This menu item's label
  95   * This is package-private to avoid an accessor method.
  96   */
  97 String label = "";
  98
  99 /**
 100   * @serial The shortcut for this menu item, if any
 101   */
 102 private MenuShortcut shortcut;
 103
 104 // The list of action listeners for this menu item.
 105 private transient ActionListener action_listeners;
 106
 107   protected class AccessibleAWTMenuItem
 108     extends MenuComponent.AccessibleAWTMenuComponent
 109     implements AccessibleAction, AccessibleValue
 110   {
 111     private static final long serialVersionUID = -217847831945965825L;
 112
 113     /** Constructor */
 114     protected AccessibleAWTMenuItem()
 115     {
 116       super();
 117     }
 118
 119
 120
 121     public String getAccessibleName()
 122     {
 123       return label;
 124     }
 125
 126     public AccessibleAction getAccessibleAction()
 127     {
 128       return this;
 129     }
 130
 131     public AccessibleRole getAccessibleRole()
 132     {
 133       return AccessibleRole.MENU_ITEM;
 134     }
 135
 136     /* (non-Javadoc)
 137      * @see javax.accessibility.AccessibleAction#getAccessibleActionCount()
 138      */
 139     public int getAccessibleActionCount()
 140     {
 141       return 1;
 142     }
 143
 144     /* (non-Javadoc)
 145      * @see javax.accessibility.AccessibleAction#getAccessibleActionDescription(int)
 146      */
 147     public String getAccessibleActionDescription(int i)
 148     {
 149       if (i == 0)
 150         return label;
 151       else
 152         return null;
 153     }
 154
 155     /* (non-Javadoc)
 156      * @see javax.accessibility.AccessibleAction#doAccessibleAction(int)
 157      */
 158     public boolean doAccessibleAction(int i)
 159     {
 160       if (i != 0)
 161         return false;
 162       processActionEvent(new ActionEvent(this, ActionEvent.ACTION_PERFORMED, actionCommand));
 163       return true;
 164     }
 165
 166     public AccessibleValue getAccessibleValue()
 167     {
 168       return this;
 169     }
 170
 171     /* (non-Javadoc)
 172      * @see javax.accessibility.AccessibleValue#getCurrentAccessibleValue()
 173      */
 174     public Number getCurrentAccessibleValue()
 175     {
 176       return (enabled) ? new Integer(1) : new Integer(0);
 177     }
 178
 179     /* (non-Javadoc)
 180      * @see javax.accessibility.AccessibleValue#setCurrentAccessibleValue(java.lang.Number)
 181      */
 182     public boolean setCurrentAccessibleValue(Number number)
 183     {
 184       boolean result = (number.intValue() != 0);
 185       // this. is required by javac 1.3, otherwise it is confused with
 186       // MenuItem.this.setEnabled.
 187       this.setEnabled(result);
 188       return result;
 189     }
 190
 191     /* (non-Javadoc)
 192      * @see javax.accessibility.AccessibleValue#getMinimumAccessibleValue()
 193      */
 194     public Number getMinimumAccessibleValue()
 195     {
 196       return new Integer(0);
 197     }
 198
 199     /* (non-Javadoc)
 200      * @see javax.accessibility.AccessibleValue#getMaximumAccessibleValue()
 201      */
 202     public Number getMaximumAccessibleValue()
 203     {
 204       return new Integer(0);
 205     }
 206
 207   }
 208
 209
 210 /*************************************************************************/
 211
 212 /*
 213  * Constructors
 214  */
 215
 216 /**
 217   * Initializes a new instance of <code>MenuItem</code> with no label
 218   * and no shortcut.
 219   */
 220 public
 221 MenuItem()
 222 {
 223 }
 224
 225 /*************************************************************************/
 226
 227 /**
 228   * Initializes a new instance of <code>MenuItem</code> with the specified
 229   * label and no shortcut.
 230   *
 231   * @param label The label for this menu item.
 232   */
 233 public
 234 MenuItem(String label)
 235 {
 236   this.label = label;
 237 }
 238
 239 /*************************************************************************/
 240
 241 /**
 242   * Initializes a new instance of <code>MenuItem</code> with the specified
 243   * label and shortcut.
 244   *
 245   * @param label The label for this menu item.
 246   * @param shortcut The shortcut for this menu item.
 247   */
 248 public
 249 MenuItem(String label, MenuShortcut shortcut)
 250 {
 251   this.label = label;
 252   this.shortcut = shortcut;
 253 }
 254
 255 /*************************************************************************/
 256
 257 /*
 258  * Instance Methods
 259  */
 260
 261 /**
 262   * Returns the label for this menu item, which may be <code>null</code>.
 263   *
 264   * @return The label for this menu item.
 265   */
 266 public String
 267 getLabel()
 268 {
 269   return(label);
 270 }
 271
 272 /*************************************************************************/
 273
 274 /**
 275   * This method sets the label for this menu to the specified value.
 276   *
 277   * @param label The new label for this menu item.
 278   */
 279 public synchronized void
 280 setLabel(String label)
 281 {
 282   this.label = label;
 283   if (peer != null)
 284     {
 285       MenuItemPeer mp = (MenuItemPeer) peer;
 286       mp.setLabel (label);
 287     }
 288 }
 289
 290 /*************************************************************************/
 291
 292 /**
 293   * Tests whether or not this menu item is enabled.
 294   *
 295   * @return <code>true</code> if this menu item is enabled, <code>false</code>
 296   * otherwise.
 297   */
 298 public boolean
 299 isEnabled()
 300 {
 301   return(enabled);
 302 }
 303
 304 /*************************************************************************/
 305
 306 /**
 307   * Sets the enabled status of this menu item.
 308   *
 309   * @param enabled <code>true</code> to enable this menu item,
 310   * <code>false</code> otherwise.
 311   */
 312 public synchronized void
 313 setEnabled(boolean enabled)
 314 {
 315   enable (enabled);
 316 }
 317
 318 /*************************************************************************/
 319
 320 /**
 321   * Sets the enabled status of this menu item.
 322   *
 323   * @param enabled <code>true</code> to enable this menu item,
 324   * <code>false</code> otherwise.
 325   *
 326   * @deprecated This method is deprecated in favor of <code>setEnabled()</code>.
 327   */
 328 public void
 329 enable(boolean enabled)
 330 {
 331   if (enabled)
 332     enable ();
 333   else
 334     disable ();
 335 }
 336
 337 /*************************************************************************/
 338
 339 /**
 340   * Enables this menu item.
 341   *
 342   * @deprecated This method is deprecated in favor of <code>setEnabled()</code>.
 343   */
 344 public void
 345 enable()
 346 {
 347   if (enabled)
 348     return;
 349
 350   this.enabled = true;
 351   if (peer != null)
 352     ((MenuItemPeer) peer).setEnabled (true);
 353 }
 354
 355 /*************************************************************************/
 356
 357 /**
 358   * Disables this menu item.
 359   *
 360   * @deprecated This method is deprecated in favor of <code>setEnabled()</code>.
 361   */
 362 public void
 363 disable()
 364 {
 365   if (!enabled)
 366     return;
 367
 368   this.enabled = false;
 369   if (peer != null)
 370     ((MenuItemPeer) peer).setEnabled (false);
 371 }
 372
 373 /*************************************************************************/
 374
 375 /**
 376   * Returns the shortcut for this menu item, which may be <code>null</code>.
 377   *
 378   * @return The shortcut for this menu item.
 379   */
 380 public MenuShortcut
 381 getShortcut()
 382 {
 383   return(shortcut);
 384 }
 385
 386 /*************************************************************************/
 387
 388 /**
 389   * Sets the shortcut for this menu item to the specified value.  This
 390   * must be done before the native peer is created.
 391   *
 392   * @param shortcut The new shortcut for this menu item.
 393   */
 394 public void
 395 setShortcut(MenuShortcut shortcut)
 396 {
 397   this.shortcut = shortcut;
 398 }
 399
 400 /*************************************************************************/
 401
 402 /**
 403   * Deletes the shortcut for this menu item if one exists.  This must be
 404   * done before the native peer is created.
 405   */
 406 public void
 407 deleteShortcut()
 408 {
 409   shortcut = null;
 410 }
 411
 412 /*************************************************************************/
 413
 414 /**
 415   * Returns the name of the action command in the action events
 416   * generated by this menu item.
 417   *
 418   * @return The action command name
 419   */
 420 public String
 421 getActionCommand()
 422 {
 423   if (actionCommand == null)
 424     return label;
 425   else
 426     return actionCommand;
 427 }
 428
 429 /*************************************************************************/
 430
 431 /**
 432   * Sets the name of the action command in the action events generated by
 433   * this menu item.
 434   *
 435   * @param actionCommand The new action command name.
 436   */
 437 public void
 438 setActionCommand(String actionCommand)
 439 {
 440   this.actionCommand = actionCommand;
 441 }
 442
 443 /*************************************************************************/
 444
 445 /**
 446   * Enables the specified events.  This is done automatically when a
 447   * listener is added and does not normally need to be done by
 448   * application code.
 449   *
 450   * @param events The events to enable, which should be the bit masks
 451   * from <code>AWTEvent</code>.
 452   */
 453 protected final void
 454 enableEvents(long events)
 455 {
 456   eventMask |= events;
 457   // TODO: see comment in Component.enableEvents().
 458 }
 459
 460 /*************************************************************************/
 461
 462 /**
 463   * Disables the specified events.
 464   *
 465   * @param events The events to enable, which should be the bit masks
 466   * from <code>AWTEvent</code>.
 467   */
 468 protected final void
 469 disableEvents(long events)
 470 {
 471   eventMask &= ~events;
 472 }
 473
 474 /*************************************************************************/
 475
 476 /**
 477   * Creates the native peer for this object.
 478   */
 479 public void
 480 addNotify()
 481 {
 482   if (peer == null)
 483     peer = getToolkit ().createMenuItem (this);
 484 }
 485
 486 /*************************************************************************/
 487
 488 /**
 489   * Adds the specified listener to the list of registered action listeners
 490   * for this component.
 491   *
 492   * @param listener The listener to add.
 493   */
 494 public synchronized void
 495 addActionListener(ActionListener listener)
 496 {
 497   action_listeners = AWTEventMulticaster.add(action_listeners, listener);
 498
 499   enableEvents(AWTEvent.ACTION_EVENT_MASK);
 500 }
 501
 502 public synchronized void
 503 removeActionListener(ActionListener l)
 504 {
 505   action_listeners = AWTEventMulticaster.remove(action_listeners, l);
 506 }
 507
 508   public synchronized ActionListener[] getActionListeners()
 509   {
 510     return (ActionListener[])
 511       AWTEventMulticaster.getListeners(action_listeners,
 512                                        ActionListener.class);
 513   }
 514
 515 /** Returns all registered EventListers of the given listenerType.
 516  * listenerType must be a subclass of EventListener, or a
 517  * ClassClassException is thrown.
 518  * @since 1.3
 519  */
 520   public EventListener[] getListeners(Class listenerType)
 521   {
 522     if (listenerType == ActionListener.class)
 523       return getActionListeners();
 524     return (EventListener[]) Array.newInstance(listenerType, 0);
 525   }
 526
 527 /*************************************************************************/
 528
 529 void
 530 dispatchEventImpl(AWTEvent e)
 531 {
 532   if (e.id <= ActionEvent.ACTION_LAST
 533       && e.id >= ActionEvent.ACTION_FIRST
 534       && (action_listeners != null
 535           || (eventMask & AWTEvent.ACTION_EVENT_MASK) != 0))
 536     processEvent(e);
 537
 538   // Send the event to the parent menu if it has not yet been
 539   // consumed.
 540   if (!e.isConsumed ())
 541     ((Menu) getParent ()).processEvent (e);
 542 }
 543
 544 /**
 545   * Processes the specified event by calling <code>processActionEvent()</code>
 546   * if it is an instance of <code>ActionEvent</code>.
 547   *
 548   * @param event The event to process.
 549   */
 550 protected void
 551 processEvent(AWTEvent event)
 552 {
 553   if (event instanceof ActionEvent)
 554     processActionEvent((ActionEvent)event);
 555 }
 556
 557 /*************************************************************************/
 558
 559 /**
 560   * Processes the specified event by dispatching it to any registered listeners.
 561   *
 562   * @param event The event to process.
 563   */
 564 protected void
 565 processActionEvent(ActionEvent event)
 566 {
 567   if (action_listeners != null)
 568     {
 569       event.setSource(this);
 570       action_listeners.actionPerformed(event);
 571     }
 572 }
 573
 574 /*************************************************************************/
 575
 576 /**
 577   * Returns a debugging string for this object.
 578   *
 579   * @return A debugging string for this object.
 580   */
 581 public String
 582 paramString()
 583 {
 584   return ("label=" + label + ",enabled=" + enabled +
 585           ",actionCommand=" + actionCommand + "," + super.paramString());
 586 }
 587
 588 /**
 589  * Gets the AccessibleContext associated with this <code>MenuItem</code>.
 590  * The context is created, if necessary.
 591  *
 592  * @return the associated context
 593  */
 594 public AccessibleContext getAccessibleContext()
 595 {
 596   /* Create the context if this is the first request */
 597   if (accessibleContext == null)
 598     accessibleContext = new AccessibleAWTMenuItem();
 599   return accessibleContext;
 600 }
 601
 602 } // class MenuItem