Source for java.awt.MenuItem

 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: 
 68:  /**
 69:  * The number used to generate the name returned by getName.
 70:  */
 71:  private static transient long next_menuitem_number;
 72: 
 73:  // Serialization Constant
 74:  private static final long serialVersionUID = - 21757335363267194L;
 75: 
 76:  /*************************************************************************/
 77: 
 78:  /*
 79:  * Instance Variables
 80:  */
 81: 
 82:  /**
 83:  * @serial The name of the action command generated by this item.
 84:  * This is package-private to avoid an accessor method.
 85:  */
 86:  String actionCommand;
 87: 
 88:  /**
 89:  * @serial Indicates whether or not this menu item is enabled.
 90:  * This is package-private to avoid an accessor method.
 91:  */
 92:  boolean enabled = true;
 93: 
 94:  /**
 95:  * @serial The mask of events that are enabled for this menu item.
 96:  */
 97:  long eventMask;
 98: 
 99:  /**
 100:  * @serial This menu item's label
 101:  * This is package-private to avoid an accessor method.
 102:  */
 103:  String label = "";
 104: 
 105:  /**
 106:  * @serial The shortcut for this menu item, if any
 107:  */
 108:  private MenuShortcut shortcut;
 109: 
 110:  // The list of action listeners for this menu item.
 111:  private transient ActionListener action_listeners;
 112: 
 113:  protected class AccessibleAWTMenuItem
 114:  extends MenuComponent.AccessibleAWTMenuComponent
 115:  implements AccessibleAction, AccessibleValue
 116:  {
 117:  private static final long serialVersionUID = -217847831945965825L;
 118: 
 119:  /** Constructor */
 120:  protected AccessibleAWTMenuItem()
 121:  {
 122:  super();
 123:  }
 124:  
 125:  
 126:  
 127:  public String getAccessibleName()
 128:  {
 129:  return label;
 130:  }
 131:  
 132:  public AccessibleAction getAccessibleAction()
 133:  {
 134:  return this;
 135:  }
 136:  
 137:  public AccessibleRole getAccessibleRole()
 138:  {
 139:  return AccessibleRole.MENU_ITEM;
 140:  }
 141:  
 142:  /* (non-Javadoc)
 143:  * @see javax.accessibility.AccessibleAction#getAccessibleActionCount()
 144:  */
 145:  public int getAccessibleActionCount()
 146:  {
 147:  return 1;
 148:  }
 149: 
 150:  /* (non-Javadoc)
 151:  * @see javax.accessibility.AccessibleAction#getAccessibleActionDescription(int)
 152:  */
 153:  public String getAccessibleActionDescription(int i)
 154:  {
 155:  if (i == 0)
 156:  return label;
 157:  else
 158:  return null;
 159:  }
 160: 
 161:  /* (non-Javadoc)
 162:  * @see javax.accessibility.AccessibleAction#doAccessibleAction(int)
 163:  */
 164:  public boolean doAccessibleAction(int i)
 165:  {
 166:  if (i != 0)
 167:  return false;
 168:  processActionEvent(new ActionEvent(this, ActionEvent.ACTION_PERFORMED, actionCommand));
 169:  return true;
 170:  }
 171: 
 172:  public AccessibleValue getAccessibleValue()
 173:  {
 174:  return this;
 175:  }
 176:  
 177:  /* (non-Javadoc)
 178:  * @see javax.accessibility.AccessibleValue#getCurrentAccessibleValue()
 179:  */
 180:  public Number getCurrentAccessibleValue()
 181:  {
 182:  return (enabled) ? new Integer(1) : new Integer(0);
 183:  }
 184: 
 185:  /* (non-Javadoc)
 186:  * @see javax.accessibility.AccessibleValue#setCurrentAccessibleValue(java.lang.Number)
 187:  */
 188:  public boolean setCurrentAccessibleValue(Number number)
 189:  {
 190:  boolean result = (number.intValue() != 0);
 191:  // this. is required by javac 1.3, otherwise it is confused with
 192:  // MenuItem.this.setEnabled.
 193:  this.setEnabled(result);
 194:  return result; 
 195:  }
 196: 
 197:  /* (non-Javadoc)
 198:  * @see javax.accessibility.AccessibleValue#getMinimumAccessibleValue()
 199:  */
 200:  public Number getMinimumAccessibleValue()
 201:  {
 202:  return new Integer(0);
 203:  }
 204: 
 205:  /* (non-Javadoc)
 206:  * @see javax.accessibility.AccessibleValue#getMaximumAccessibleValue()
 207:  */
 208:  public Number getMaximumAccessibleValue()
 209:  {
 210:  return new Integer(0);
 211:  }
 212:  
 213:  }
 214: 
 215: 
 216:  /*************************************************************************/
 217: 
 218:  /*
 219:  * Constructors
 220:  */
 221: 
 222:  /**
 223:  * Initializes a new instance of <code>MenuItem</code> with no label
 224:  * and no shortcut.
 225:  */
 226:  public
 227:  MenuItem()
 228: {
 229: }
 230: 
 231:  /*************************************************************************/
 232: 
 233:  /**
 234:  * Initializes a new instance of <code>MenuItem</code> with the specified
 235:  * label and no shortcut.
 236:  *
 237:  * @param label The label for this menu item.
 238:  */
 239:  public 
 240:  MenuItem(String label)
 241: {
 242:  this.label = label;
 243: }
 244: 
 245:  /*************************************************************************/
 246: 
 247:  /**
 248:  * Initializes a new instance of <code>MenuItem</code> with the specified
 249:  * label and shortcut.
 250:  *
 251:  * @param label The label for this menu item.
 252:  * @param shortcut The shortcut for this menu item.
 253:  */
 254:  public
 255:  MenuItem(String label, MenuShortcut shortcut)
 256: {
 257:  this.label = label;
 258:  this.shortcut = shortcut;
 259: }
 260: 
 261:  /*************************************************************************/
 262: 
 263:  /*
 264:  * Instance Methods
 265:  */
 266: 
 267:  /**
 268:  * Returns the label for this menu item, which may be <code>null</code>.
 269:  *
 270:  * @return The label for this menu item.
 271:  */
 272:  public String
 273:  getLabel()
 274: {
 275:  return(label);
 276: }
 277: 
 278:  /*************************************************************************/
 279: 
 280:  /**
 281:  * This method sets the label for this menu to the specified value.
 282:  *
 283:  * @param label The new label for this menu item.
 284:  */
 285:  public synchronized void
 286:  setLabel(String label)
 287: {
 288:  this.label = label;
 289:  if (peer != null)
 290:  {
 291:  MenuItemPeer mp = (MenuItemPeer) peer;
 292:  mp.setLabel (label);
 293:  }
 294: }
 295: 
 296:  /*************************************************************************/
 297: 
 298:  /**
 299:  * Tests whether or not this menu item is enabled.
 300:  *
 301:  * @return <code>true</code> if this menu item is enabled, <code>false</code>
 302:  * otherwise.
 303:  */
 304:  public boolean
 305:  isEnabled()
 306: {
 307:  return(enabled);
 308: }
 309: 
 310:  /*************************************************************************/
 311: 
 312:  /**
 313:  * Sets the enabled status of this menu item.
 314:  * 
 315:  * @param enabled <code>true</code> to enable this menu item,
 316:  * <code>false</code> otherwise.
 317:  */
 318:  public synchronized void
 319:  setEnabled(boolean enabled)
 320: {
 321:  enable (enabled);
 322: }
 323: 
 324:  /*************************************************************************/
 325: 
 326:  /**
 327:  * Sets the enabled status of this menu item.
 328:  * 
 329:  * @param enabled <code>true</code> to enable this menu item,
 330:  * <code>false</code> otherwise.
 331:  *
 332:  * @deprecated This method is deprecated in favor of <code>setEnabled()</code>.
 333:  */
 334:  public void
 335:  enable(boolean enabled)
 336: {
 337:  if (enabled)
 338:  enable ();
 339:  else
 340:  disable ();
 341: }
 342: 
 343:  /*************************************************************************/
 344: 
 345:  /**
 346:  * Enables this menu item.
 347:  *
 348:  * @deprecated This method is deprecated in favor of <code>setEnabled()</code>.
 349:  */
 350:  public void
 351:  enable()
 352: {
 353:  if (enabled)
 354:  return;
 355: 
 356:  this.enabled = true;
 357:  if (peer != null)
 358:  ((MenuItemPeer) peer).setEnabled (true);
 359: }
 360: 
 361:  /*************************************************************************/
 362: 
 363:  /**
 364:  * Disables this menu item.
 365:  *
 366:  * @deprecated This method is deprecated in favor of <code>setEnabled()</code>.
 367:  */
 368:  public void
 369:  disable()
 370: {
 371:  if (!enabled)
 372:  return;
 373: 
 374:  this.enabled = false;
 375:  if (peer != null)
 376:  ((MenuItemPeer) peer).setEnabled (false);
 377: }
 378: 
 379:  /*************************************************************************/
 380: 
 381:  /**
 382:  * Returns the shortcut for this menu item, which may be <code>null</code>.
 383:  *
 384:  * @return The shortcut for this menu item.
 385:  */
 386:  public MenuShortcut
 387:  getShortcut()
 388: {
 389:  return(shortcut);
 390: }
 391: 
 392:  /*************************************************************************/
 393: 
 394:  /**
 395:  * Sets the shortcut for this menu item to the specified value. This
 396:  * must be done before the native peer is created.
 397:  *
 398:  * @param shortcut The new shortcut for this menu item.
 399:  */
 400:  public void
 401:  setShortcut(MenuShortcut shortcut)
 402: {
 403:  this.shortcut = shortcut;
 404: }
 405: 
 406:  /*************************************************************************/
 407: 
 408:  /**
 409:  * Deletes the shortcut for this menu item if one exists. This must be
 410:  * done before the native peer is created.
 411:  */
 412:  public void
 413:  deleteShortcut()
 414: {
 415:  shortcut = null;
 416: }
 417: 
 418:  /*************************************************************************/
 419: 
 420:  /**
 421:  * Returns the name of the action command in the action events
 422:  * generated by this menu item.
 423:  *
 424:  * @return The action command name
 425:  */
 426:  public String
 427:  getActionCommand()
 428: {
 429:  if (actionCommand == null)
 430:  return label;
 431:  else
 432:  return actionCommand;
 433: }
 434: 
 435:  /*************************************************************************/
 436: 
 437:  /**
 438:  * Sets the name of the action command in the action events generated by
 439:  * this menu item.
 440:  *
 441:  * @param actionCommand The new action command name.
 442:  */
 443:  public void
 444:  setActionCommand(String actionCommand)
 445: {
 446:  this.actionCommand = actionCommand;
 447: }
 448: 
 449:  /*************************************************************************/
 450: 
 451:  /**
 452:  * Enables the specified events. This is done automatically when a 
 453:  * listener is added and does not normally need to be done by
 454:  * application code.
 455:  *
 456:  * @param events The events to enable, which should be the bit masks
 457:  * from <code>AWTEvent</code>.
 458:  */
 459:  protected final void
 460:  enableEvents(long events)
 461: {
 462:  eventMask |= events;
 463:  // TODO: see comment in Component.enableEvents(). 
 464: }
 465: 
 466:  /*************************************************************************/
 467: 
 468:  /**
 469:  * Disables the specified events.
 470:  *
 471:  * @param events The events to enable, which should be the bit masks
 472:  * from <code>AWTEvent</code>.
 473:  */
 474:  protected final void
 475:  disableEvents(long events)
 476: {
 477:  eventMask &= ~events;
 478: }
 479: 
 480:  /*************************************************************************/
 481: 
 482:  /**
 483:  * Creates the native peer for this object.
 484:  */
 485:  public void
 486:  addNotify()
 487: {
 488:  if (peer == null)
 489:  peer = getToolkit ().createMenuItem (this);
 490: }
 491: 
 492:  /*************************************************************************/
 493: 
 494:  /**
 495:  * Adds the specified listener to the list of registered action listeners
 496:  * for this component.
 497:  *
 498:  * @param listener The listener to add.
 499:  */
 500:  public synchronized void
 501:  addActionListener(ActionListener listener)
 502: {
 503:  action_listeners = AWTEventMulticaster.add(action_listeners, listener);
 504: 
 505:  enableEvents(AWTEvent.ACTION_EVENT_MASK);
 506: }
 507: 
 508:  public synchronized void
 509:  removeActionListener(ActionListener l)
 510: {
 511:  action_listeners = AWTEventMulticaster.remove(action_listeners, l);
 512: }
 513: 
 514:  public synchronized ActionListener[] getActionListeners()
 515:  {
 516:  return (ActionListener[])
 517:  AWTEventMulticaster.getListeners(action_listeners,
 518:  ActionListener.class);
 519:  }
 520: 
 521:  /** Returns all registered EventListers of the given listenerType. 
 522:  * listenerType must be a subclass of EventListener, or a 
 523:  * ClassClassException is thrown.
 524:  * @since 1.3 
 525:  */
 526:  public <T extends EventListener> T[] getListeners(Class<T> listenerType)
 527:  {
 528:  if (listenerType == ActionListener.class)
 529:  return (T[]) getActionListeners();
 530:  return (T[]) Array.newInstance(listenerType, 0);
 531:  }
 532: 
 533:  /*************************************************************************/
 534: 
 535:  void
 536:  dispatchEventImpl(AWTEvent e)
 537: {
 538:  if (e.id <= ActionEvent.ACTION_LAST 
 539:  && e.id >= ActionEvent.ACTION_FIRST
 540:  && (action_listeners != null
 541:  || (eventMask & AWTEvent.ACTION_EVENT_MASK) != 0))
 542:  processEvent(e);
 543: 
 544:  // Send the event to the parent menu if it has not yet been
 545:  // consumed.
 546:  if (!e.isConsumed ())
 547:  ((Menu) getParent ()).processEvent (e);
 548: }
 549: 
 550:  /**
 551:  * Processes the specified event by calling <code>processActionEvent()</code>
 552:  * if it is an instance of <code>ActionEvent</code>.
 553:  *
 554:  * @param event The event to process.
 555:  */
 556:  protected void
 557:  processEvent(AWTEvent event)
 558: {
 559:  if (event instanceof ActionEvent)
 560:  processActionEvent((ActionEvent)event);
 561: }
 562: 
 563:  /*************************************************************************/
 564: 
 565:  /**
 566:  * Processes the specified event by dispatching it to any registered listeners.
 567:  *
 568:  * @param event The event to process.
 569:  */
 570:  protected void
 571:  processActionEvent(ActionEvent event)
 572: {
 573:  if (action_listeners != null)
 574:  {
 575:  event.setSource(this);
 576:  action_listeners.actionPerformed(event);
 577:  }
 578: }
 579: 
 580:  /*************************************************************************/
 581: 
 582:  /**
 583:  * Returns a debugging string for this object.
 584:  *
 585:  * @return A debugging string for this object.
 586:  */
 587:  public String
 588:  paramString()
 589: {
 590:  return ("label=" + label + ",enabled=" + enabled +
 591:  ",actionCommand=" + actionCommand + "," + super.paramString());
 592: }
 593: 
 594:  /**
 595:  * Gets the AccessibleContext associated with this <code>MenuItem</code>.
 596:  * The context is created, if necessary.
 597:  *
 598:  * @return the associated context
 599:  */
 600:  public AccessibleContext getAccessibleContext()
 601: {
 602:  /* Create the context if this is the first request */
 603:  if (accessibleContext == null)
 604:  accessibleContext = new AccessibleAWTMenuItem();
 605:  return accessibleContext;
 606: }
 607: 
 608:  /**
 609:  * Generate a unique name for this <code>MenuItem</code>.
 610:  *
 611:  * @return A unique name for this <code>MenuItem</code>.
 612:  */
 613:  String generateName()
 614: {
 615:  return "menuitem" + getUniqueLong();
 616: }
 617: 
 618:  private static synchronized long getUniqueLong()
 619: {
 620:  return next_menuitem_number++;
 621: }
 622: 
 623: } // class MenuItem