libjava/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., 59 Temple Place, Suite 330, Boston, MA
  19 02111-1307 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   */
  79 private String actionCommand;
  80
  81 /**
  82   * @serial Indicates whether or not this menu item is enabled.
  83   */
  84 private boolean enabled = true;
  85
  86 /**
  87   * @serial The mask of events that are enabled for this menu item.
  88   */
  89 long eventMask;
  90
  91 /**
  92   * @serial This menu item's label
  93   */
  94 private String label;
  95
  96 /**
  97   * @serial The shortcut for this menu item, if any
  98   */
  99 private MenuShortcut shortcut;
 100
 101 // The list of action listeners for this menu item.
 102 private transient ActionListener action_listeners;
 103
 104   protected class AccessibleAWTMenuItem
 105     extends MenuComponent.AccessibleAWTMenuComponent
 106     implements AccessibleAction, AccessibleValue
 107   {
 108     /** Constructor */
 109     public AccessibleAWTMenuItem()
 110     {
 111       super();
 112     }
 113
 114
 115
 116     public String getAccessibleName()
 117     {
 118       return label;
 119     }
 120
 121     public AccessibleAction getAccessibleAction()
 122     {
 123       return this;
 124     }
 125
 126     public AccessibleRole getAccessibleRole()
 127     {
 128       return AccessibleRole.MENU_ITEM;
 129     }
 130
 131     /* (non-Javadoc)
 132      * @see javax.accessibility.AccessibleAction#getAccessibleActionCount()
 133      */
 134     public int getAccessibleActionCount()
 135     {
 136       return 1;
 137     }
 138
 139     /* (non-Javadoc)
 140      * @see javax.accessibility.AccessibleAction#getAccessibleActionDescription(int)
 141      */
 142     public String getAccessibleActionDescription(int i)
 143     {
 144       if (i == 0)
 145         return label;
 146       else
 147         return null;
 148     }
 149
 150     /* (non-Javadoc)
 151      * @see javax.accessibility.AccessibleAction#doAccessibleAction(int)
 152      */
 153     public boolean doAccessibleAction(int i)
 154     {
 155       if (i != 0)
 156         return false;
 157       processActionEvent(new ActionEvent(this, ActionEvent.ACTION_PERFORMED, actionCommand));
 158       return true;
 159     }
 160
 161     public AccessibleValue getAccessibleValue()
 162     {
 163       return this;
 164     }
 165
 166     /* (non-Javadoc)
 167      * @see javax.accessibility.AccessibleValue#getCurrentAccessibleValue()
 168      */
 169     public Number getCurrentAccessibleValue()
 170     {
 171       return (enabled) ? new Integer(1) : new Integer(0);
 172     }
 173
 174     /* (non-Javadoc)
 175      * @see javax.accessibility.AccessibleValue#setCurrentAccessibleValue(java.lang.Number)
 176      */
 177     public boolean setCurrentAccessibleValue(Number number)
 178     {
 179       if (number.intValue() == 0)
 180         {
 181           setEnabled(false);
 182           return false;
 183         }
 184
 185       setEnabled(true);
 186       return true;
 187     }
 188
 189     /* (non-Javadoc)
 190      * @see javax.accessibility.AccessibleValue#getMinimumAccessibleValue()
 191      */
 192     public Number getMinimumAccessibleValue()
 193     {
 194       return new Integer(0);
 195     }
 196
 197     /* (non-Javadoc)
 198      * @see javax.accessibility.AccessibleValue#getMaximumAccessibleValue()
 199      */
 200     public Number getMaximumAccessibleValue()
 201     {
 202       return new Integer(0);
 203     }
 204
 205   }
 206
 207
 208 /*************************************************************************/
 209
 210 /*
 211  * Constructors
 212  */
 213
 214 /**
 215   * Initializes a new instance of <code>MenuItem</code> with no label
 216   * and no shortcut.
 217   */
 218 public
 219 MenuItem()
 220 {
 221 }
 222
 223 /*************************************************************************/
 224
 225 /**
 226   * Initializes a new instance of <code>MenuItem</code> with the specified
 227   * label and no shortcut.
 228   *
 229   * @param label The label for this menu item.
 230   */
 231 public
 232 MenuItem(String label)
 233 {
 234   this.label = label;
 235 }
 236
 237 /*************************************************************************/
 238
 239 /**
 240   * Initializes a new instance of <code>MenuItem</code> with the specified
 241   * label and shortcut.
 242   *
 243   * @param label The label for this menu item.
 244   * @param shortcut The shortcut for this menu item.
 245   */
 246 public
 247 MenuItem(String label, MenuShortcut shortcut)
 248 {
 249   this.label = label;
 250   this.shortcut = shortcut;
 251 }
 252
 253 /*************************************************************************/
 254
 255 /*
 256  * Instance Methods
 257  */
 258
 259 /**
 260   * Returns the label for this menu item, which may be <code>null</code>.
 261   *
 262   * @return The label for this menu item.
 263   */
 264 public String
 265 getLabel()
 266 {
 267   return(label);
 268 }
 269
 270 /*************************************************************************/
 271
 272 /**
 273   * This method sets the label for this menu to the specified value.
 274   *
 275   * @param label The new label for this menu item.
 276   */
 277 public synchronized void
 278 setLabel(String label)
 279 {
 280   this.label = label;
 281   if (peer != null)
 282     {
 283       MenuItemPeer mp = (MenuItemPeer) peer;
 284       mp.setLabel (label);
 285     }
 286 }
 287
 288 /*************************************************************************/
 289
 290 /**
 291   * Tests whether or not this menu item is enabled.
 292   *
 293   * @return <code>true</code> if this menu item is enabled, <code>false</code>
 294   * otherwise.
 295   */
 296 public boolean
 297 isEnabled()
 298 {
 299   return(enabled);
 300 }
 301
 302 /*************************************************************************/
 303
 304 /**
 305   * Sets the enabled status of this menu item.
 306   *
 307   * @param enabled <code>true</code> to enable this menu item,
 308   * <code>false</code> otherwise.
 309   */
 310 public synchronized void
 311 setEnabled(boolean enabled)
 312 {
 313   enable (enabled);
 314 }
 315
 316 /*************************************************************************/
 317
 318 /**
 319   * Sets the enabled status of this menu item.
 320   *
 321   * @param enabled <code>true</code> to enable this menu item,
 322   * <code>false</code> otherwise.
 323   *
 324   * @deprecated This method is deprecated in favor of <code>setEnabled()</code>.
 325   */
 326 public void
 327 enable(boolean enabled)
 328 {
 329   if (enabled)
 330     enable ();
 331   else
 332     disable ();
 333 }
 334
 335 /*************************************************************************/
 336
 337 /**
 338   * Enables this menu item.
 339   *
 340   * @deprecated This method is deprecated in favor of <code>setEnabled()</code>.
 341   */
 342 public void
 343 enable()
 344 {
 345   if (enabled)
 346     return;
 347
 348   this.enabled = true;
 349   if (peer != null)
 350     ((MenuItemPeer) peer).setEnabled (true);
 351 }
 352
 353 /*************************************************************************/
 354
 355 /**
 356   * Disables this menu item.
 357   *
 358   * @deprecated This method is deprecated in favor of <code>setEnabled()</code>.
 359   */
 360 public void
 361 disable()
 362 {
 363   if (!enabled)
 364     return;
 365
 366   this.enabled = false;
 367   if (peer != null)
 368     ((MenuItemPeer) peer).setEnabled (false);
 369 }
 370
 371 /*************************************************************************/
 372
 373 /**
 374   * Returns the shortcut for this menu item, which may be <code>null</code>.
 375   *
 376   * @return The shortcut for this menu item.
 377   */
 378 public MenuShortcut
 379 getShortcut()
 380 {
 381   return(shortcut);
 382 }
 383
 384 /*************************************************************************/
 385
 386 /**
 387   * Sets the shortcut for this menu item to the specified value.  This
 388   * must be done before the native peer is created.
 389   *
 390   * @param shortcut The new shortcut for this menu item.
 391   */
 392 public void
 393 setShortcut(MenuShortcut shortcut)
 394 {
 395   this.shortcut = shortcut;
 396 }
 397
 398 /*************************************************************************/
 399
 400 /**
 401   * Deletes the shortcut for this menu item if one exists.  This must be
 402   * done before the native peer is created.
 403   */
 404 public void
 405 deleteShortcut()
 406 {
 407   shortcut = null;
 408 }
 409
 410 /*************************************************************************/
 411
 412 /**
 413   * Returns the name of the action command in the action events
 414   * generated by this menu item.
 415   *
 416   * @return The action command name
 417   */
 418 public String
 419 getActionCommand()
 420 {
 421   if (actionCommand == null)
 422     return label;
 423   else
 424     return actionCommand;
 425 }
 426
 427 /*************************************************************************/
 428
 429 /**
 430   * Sets the name of the action command in the action events generated by
 431   * this menu item.
 432   *
 433   * @param actionCommand The new action command name.
 434   */
 435 public void
 436 setActionCommand(String actionCommand)
 437 {
 438   this.actionCommand = actionCommand;
 439 }
 440
 441 /*************************************************************************/
 442
 443 /**
 444   * Enables the specified events.  This is done automatically when a
 445   * listener is added and does not normally need to be done by
 446   * application code.
 447   *
 448   * @param events The events to enable, which should be the bit masks
 449   * from <code>AWTEvent</code>.
 450   */
 451 protected final void
 452 enableEvents(long events)
 453 {
 454   eventMask |= events;
 455   // TODO: see comment in Component.enableEvents().
 456 }
 457
 458 /*************************************************************************/
 459
 460 /**
 461   * Disables the specified events.
 462   *
 463   * @param events The events to enable, which should be the bit masks
 464   * from <code>AWTEvent</code>.
 465   */
 466 protected final void
 467 disableEvents(long events)
 468 {
 469   eventMask &= ~events;
 470 }
 471
 472 /*************************************************************************/
 473
 474 /**
 475   * Creates the native peer for this object.
 476   */
 477 public void
 478 addNotify()
 479 {
 480   if (peer == null)
 481     peer = getToolkit ().createMenuItem (this);
 482 }
 483
 484 /*************************************************************************/
 485
 486 /**
 487   * Adds the specified listener to the list of registered action listeners
 488   * for this component.
 489   *
 490   * @param listener The listener to add.
 491   */
 492 public synchronized void
 493 addActionListener(ActionListener listener)
 494 {
 495   action_listeners = AWTEventMulticaster.add(action_listeners, listener);
 496
 497   enableEvents(AWTEvent.ACTION_EVENT_MASK);
 498 }
 499
 500 public synchronized void
 501 removeActionListener(ActionListener l)
 502 {
 503   action_listeners = AWTEventMulticaster.remove(action_listeners, l);
 504 }
 505
 506   public synchronized ActionListener[] getActionListeners()
 507   {
 508     return (ActionListener[])
 509       AWTEventMulticaster.getListeners(action_listeners,
 510                                        ActionListener.class);
 511   }
 512
 513 /** Returns all registered EventListers of the given listenerType.
 514  * listenerType must be a subclass of EventListener, or a
 515  * ClassClassException is thrown.
 516  * @since 1.3
 517  */
 518   public EventListener[] getListeners(Class listenerType)
 519   {
 520     if (listenerType == ActionListener.class)
 521       return getActionListeners();
 522     return (EventListener[]) Array.newInstance(listenerType, 0);
 523   }
 524
 525 /*************************************************************************/
 526
 527 void
 528 dispatchEventImpl(AWTEvent e)
 529 {
 530   if (e.id <= ActionEvent.ACTION_LAST
 531       && e.id >= ActionEvent.ACTION_FIRST
 532       && (action_listeners != null
 533           || (eventMask & AWTEvent.ACTION_EVENT_MASK) != 0))
 534     processEvent(e);
 535
 536   // Send the event to the parent menu if it has not yet been
 537   // consumed.
 538   if (!e.isConsumed ())
 539     ((Menu) getParent ()).processEvent (e);
 540 }
 541
 542 /**
 543   * Processes the specified event by calling <code>processActionEvent()</code>
 544   * if it is an instance of <code>ActionEvent</code>.
 545   *
 546   * @param event The event to process.
 547   */
 548 protected void
 549 processEvent(AWTEvent event)
 550 {
 551   if (event instanceof ActionEvent)
 552     processActionEvent((ActionEvent)event);
 553 }
 554
 555 /*************************************************************************/
 556
 557 /**
 558   * Processes the specified event by dispatching it to any registered listeners.
 559   *
 560   * @param event The event to process.
 561   */
 562 protected void
 563 processActionEvent(ActionEvent event)
 564 {
 565   if (action_listeners != null)
 566     {
 567       event.setSource(this);
 568       action_listeners.actionPerformed(event);
 569     }
 570 }
 571
 572 /*************************************************************************/
 573
 574 /**
 575   * Returns a debugging string for this object.
 576   *
 577   * @return A debugging string for this object.
 578   */
 579 public String
 580 paramString()
 581 {
 582   return ("label=" + label + ",enabled=" + enabled +
 583           ",actionCommand=" + actionCommand + "," + super.paramString());
 584 }
 585
 586 /**
 587  * Gets the AccessibleContext associated with this <code>MenuItem</code>.
 588  * The context is created, if necessary.
 589  *
 590  * @return the associated context
 591  */
 592 public AccessibleContext getAccessibleContext()
 593 {
 594   /* Create the context if this is the first request */
 595   if (accessibleContext == null)
 596     accessibleContext = new AccessibleAWTMenuItem();
 597   return accessibleContext;
 598 }
 599
 600 } // class MenuItem