1 /*
2 * Copyright 1997-2006 Sun Microsystems, Inc. All Rights Reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any questions.
24 */
25
26 package javax.swing;
27
28 import java.awt.AWTEvent;
29 import java.awt.Component;
30 import java.awt.ComponentOrientation;
31 import java.awt.Container;
32 import java.awt.Dimension;
33 import java.awt.Frame;
34 import java.awt.Graphics;
35 import java.awt.GraphicsConfiguration;
36 import java.awt.GraphicsDevice;
37 import java.awt.GraphicsEnvironment;
38 import java.awt.Insets;
39 import java.awt.Point;
40 import java.awt.Polygon;
41 import java.awt.Rectangle;
42 import java.awt.Toolkit;
43 import java.awt.event;
44 import java.beans;
45
46 import java.util;
47
48 import java.io.Serializable;
49 import java.io.ObjectOutputStream;
50 import java.io.ObjectInputStream;
51 import java.io.IOException;
52
53 import javax.swing.event;
54 import javax.swing.plaf;
55 import javax.swing.plaf.basic;
56 import javax.accessibility;
57
58 import java.lang.ref.WeakReference;
59
60 /**
61 * An implementation of a menu -- a popup window containing
62 * <code>JMenuItem</code>s that
63 * is displayed when the user selects an item on the <code>JMenuBar</code>.
64 * In addition to <code>JMenuItem</code>s, a <code>JMenu</code> can
65 * also contain <code>JSeparator</code>s.
66 * <p>
67 * In essence, a menu is a button with an associated <code>JPopupMenu</code>.
68 * When the "button" is pressed, the <code>JPopupMenu</code> appears. If the
69 * "button" is on the <code>JMenuBar</code>, the menu is a top-level window.
70 * If the "button" is another menu item, then the <code>JPopupMenu</code> is
71 * "pull-right" menu.
72 * <p>
73 * Menus can be configured, and to some degree controlled, by
74 * <code><a href="Action.html">Action</a></code>s. Using an
75 * <code>Action</code> with a menu has many benefits beyond directly
76 * configuring a menu. Refer to <a href="Action.html#buttonActions">
77 * Swing Components Supporting <code>Action</code></a> for more
78 * details, and you can find more information in <a
79 * href="http://java.sun.com/docs/books/tutorial/uiswing/misc/action.html">How
80 * to Use Actions</a>, a section in <em>The Java Tutorial</em>.
81 * <p>
82 * For information and examples of using menus see
83 * <a href="http://java.sun.com/doc/books/tutorial/uiswing/components/menu.html">How to Use Menus</a>,
84 * a section in <em>The Java Tutorial.</em>
85 * <p>
86 * <strong>Warning:</strong> Swing is not thread safe. For more
87 * information see <a
88 * href="package-summary.html#threading">Swing's Threading
89 * Policy</a>.
90 * <p>
91 * <strong>Warning:</strong>
92 * Serialized objects of this class will not be compatible with
93 * future Swing releases. The current serialization support is
94 * appropriate for short term storage or RMI between applications running
95 * the same version of Swing. As of 1.4, support for long term storage
96 * of all JavaBeans<sup><font size="-2">TM</font></sup>
97 * has been added to the <code>java.beans</code> package.
98 * Please see {@link java.beans.XMLEncoder}.
99 *
100 * @beaninfo
101 * attribute: isContainer true
102 * description: A popup window containing menu items displayed in a menu bar.
103 *
104 * @author Georges Saab
105 * @author David Karlton
106 * @author Arnaud Weber
107 * @see JMenuItem
108 * @see JSeparator
109 * @see JMenuBar
110 * @see JPopupMenu
111 */
112 public class JMenu extends JMenuItem implements Accessible,MenuElement
113 {
114 /**
115 * @see #getUIClassID
116 * @see #readObject
117 */
118 private static final String uiClassID = "MenuUI";
119
120 /*
121 * The popup menu portion of the menu.
122 */
123 private JPopupMenu popupMenu;
124
125 /*
126 * The button's model listeners. Default is <code>null</code>.
127 */
128 private ChangeListener menuChangeListener = null;
129
130 /*
131 * Only one <code>MenuEvent</code> is needed for each menu since the
132 * event's only state is the source property. The source of events
133 * generated is always "this". Default is <code>null</code>.
134 */
135 private MenuEvent menuEvent = null;
136
137 /* Registry of listeners created for <code>Action-JMenuItem</code>
138 * linkage. This is needed so that references can
139 * be cleaned up at remove time to allow garbage collection
140 * Default is <code>null</code>.
141 */
142 private static Hashtable listenerRegistry = null;
143
144 /*
145 * Used by the look and feel (L&F) code to handle
146 * implementation specific menu behaviors.
147 */
148 private int delay;
149
150 /*
151 * Location of the popup component. Location is <code>null</code>
152 * if it was not customized by <code>setMenuLocation</code>
153 */
154 private Point customMenuLocation = null;
155
156 /* Diagnostic aids -- should be false for production builds. */
157 private static final boolean TRACE = false; // trace creates and disposes
158 private static final boolean VERBOSE = false; // show reuse hits/misses
159 private static final boolean DEBUG = false; // show bad params, misc.
160
161 /**
162 * Constructs a new <code>JMenu</code> with no text.
163 */
164 public JMenu() {
165 this("");
166 }
167
168 /**
169 * Constructs a new <code>JMenu</code> with the supplied string
170 * as its text.
171 *
172 * @param s the text for the menu label
173 */
174 public JMenu(String s) {
175 super(s);
176 }
177
178 /**
179 * Constructs a menu whose properties are taken from the
180 * <code>Action</code> supplied.
181 * @param a an <code>Action</code>
182 *
183 * @since 1.3
184 */
185 public JMenu(Action a) {
186 this();
187 setAction(a);
188 }
189
190 /**
191 * Constructs a new <code>JMenu</code> with the supplied string as
192 * its text and specified as a tear-off menu or not.
193 *
194 * @param s the text for the menu label
195 * @param b can the menu be torn off (not yet implemented)
196 */
197 public JMenu(String s, boolean b) {
198 this(s);
199 }
200
201
202 /**
203 * Overriden to do nothing. We want JMenu to be focusable, but
204 * <code>JMenuItem</code> doesn't want to be, thus we override this
205 * do nothing. We don't invoke <code>setFocusable(true)</code> after
206 * super's constructor has completed as this has the side effect that
207 * <code>JMenu</code> will be considered traversable via the
208 * keyboard, which we don't want. Making a Component traversable by
209 * the keyboard after invoking <code>setFocusable(true)</code> is OK,
210 * as <code>setFocusable</code> is new API
211 * and is speced as such, but internally we don't want to use it like
212 * this else we change the keyboard traversability.
213 */
214 void initFocusability() {
215 }
216
217 /**
218 * Resets the UI property with a value from the current look and feel.
219 *
220 * @see JComponent#updateUI
221 */
222 public void updateUI() {
223 setUI((MenuItemUI)UIManager.getUI(this));
224
225 if ( popupMenu != null )
226 {
227 popupMenu.setUI((PopupMenuUI)UIManager.getUI(popupMenu));
228 }
229
230 }
231
232
233 /**
234 * Returns the name of the L&F class that renders this component.
235 *
236 * @return the string "MenuUI"
237 * @see JComponent#getUIClassID
238 * @see UIDefaults#getUI
239 */
240 public String getUIClassID() {
241 return uiClassID;
242 }
243
244 // public void repaint(long tm, int x, int y, int width, int height) {
245 // Thread.currentThread().dumpStack();
246 // super.repaint(tm,x,y,width,height);
247 // }
248
249 /**
250 * Sets the data model for the "menu button" -- the label
251 * that the user clicks to open or close the menu.
252 *
253 * @param newModel the <code>ButtonModel</code>
254 * @see #getModel
255 * @beaninfo
256 * description: The menu's model
257 * bound: true
258 * expert: true
259 * hidden: true
260 */
261 public void setModel(ButtonModel newModel) {
262 ButtonModel oldModel = getModel();
263
264 super.setModel(newModel);
265
266 if (oldModel != null && menuChangeListener != null) {
267 oldModel.removeChangeListener(menuChangeListener);
268 menuChangeListener = null;
269 }
270
271 model = newModel;
272
273 if (newModel != null) {
274 menuChangeListener = createMenuChangeListener();
275 newModel.addChangeListener(menuChangeListener);
276 }
277 }
278
279 /**
280 * Returns true if the menu is currently selected (highlighted).
281 *
282 * @return true if the menu is selected, else false
283 */
284 public boolean isSelected() {
285 return getModel().isSelected();
286 }
287
288 /**
289 * Sets the selection status of the menu.
290 *
291 * @param b true to select (highlight) the menu; false to de-select
292 * the menu
293 * @beaninfo
294 * description: When the menu is selected, its popup child is shown.
295 * expert: true
296 * hidden: true
297 */
298 public void setSelected(boolean b) {
299 ButtonModel model = getModel();
300 boolean oldValue = model.isSelected();
301
302 // TIGER - 4840653
303 // Removed code which fired an AccessibleState.SELECTED
304 // PropertyChangeEvent since this resulted in two
305 // identical events being fired since
306 // AbstractButton.fireItemStateChanged also fires the
307 // same event. This caused screen readers to speak the
308 // name of the item twice.
309
310 if (b != model.isSelected()) {
311 getModel().setSelected(b);
312 }
313 }
314
315 /**
316 * Returns true if the menu's popup window is visible.
317 *
318 * @return true if the menu is visible, else false
319 */
320 public boolean isPopupMenuVisible() {
321 ensurePopupMenuCreated();
322 return popupMenu.isVisible();
323 }
324
325 /**
326 * Sets the visibility of the menu's popup. If the menu is
327 * not enabled, this method will have no effect.
328 *
329 * @param b a boolean value -- true to make the menu visible,
330 * false to hide it
331 * @beaninfo
332 * description: The popup menu's visibility
333 * expert: true
334 * hidden: true
335 */
336 public void setPopupMenuVisible(boolean b) {
337 if (DEBUG) {
338 System.out.println("in JMenu.setPopupMenuVisible " + b);
339 // Thread.dumpStack();
340 }
341
342 boolean isVisible = isPopupMenuVisible();
343 if (b != isVisible && (isEnabled() || !b)) {
344 ensurePopupMenuCreated();
345 if ((b==true) && isShowing()) {
346 // Set location of popupMenu (pulldown or pullright)
347 Point p = getCustomMenuLocation();
348 if (p == null) {
349 p = getPopupMenuOrigin();
350 }
351 getPopupMenu().show(this, p.x, p.y);
352 } else {
353 getPopupMenu().setVisible(false);
354 }
355 }
356 }
357
358 /**
359 * Computes the origin for the <code>JMenu</code>'s popup menu.
360 * This method uses Look and Feel properties named
361 * <code>Menu.menuPopupOffsetX</code>,
362 * <code>Menu.menuPopupOffsetY</code>,
363 * <code>Menu.submenuPopupOffsetX</code>, and
364 * <code>Menu.submenuPopupOffsetY</code>
365 * to adjust the exact location of popup.
366 *
367 * @return a <code>Point</code> in the coordinate space of the
368 * menu which should be used as the origin
369 * of the <code>JMenu</code>'s popup menu
370 *
371 * @since 1.3
372 */
373 protected Point getPopupMenuOrigin() {
374 int x = 0;
375 int y = 0;
376 JPopupMenu pm = getPopupMenu();
377 // Figure out the sizes needed to caclulate the menu position
378 Dimension s = getSize();
379 Dimension pmSize = pm.getSize();
380 // For the first time the menu is popped up,
381 // the size has not yet been initiated
382 if (pmSize.width==0) {
383 pmSize = pm.getPreferredSize();
384 }
385 Point position = getLocationOnScreen();
386 Toolkit toolkit = Toolkit.getDefaultToolkit();
387 GraphicsConfiguration gc = getGraphicsConfiguration();
388 Rectangle screenBounds = new Rectangle(toolkit.getScreenSize());
389 GraphicsEnvironment ge =
390 GraphicsEnvironment.getLocalGraphicsEnvironment();
391 GraphicsDevice[] gd = ge.getScreenDevices();
392 for(int i = 0; i < gd.length; i++) {
393 if(gd[i].getType() == GraphicsDevice.TYPE_RASTER_SCREEN) {
394 GraphicsConfiguration dgc =
395 gd[i].getDefaultConfiguration();
396 if(dgc.getBounds().contains(position)) {
397 gc = dgc;
398 break;
399 }
400 }
401 }
402
403
404 if (gc != null) {
405 screenBounds = gc.getBounds();
406 // take screen insets (e.g. taskbar) into account
407 Insets screenInsets = toolkit.getScreenInsets(gc);
408
409 screenBounds.width -=
410 Math.abs(screenInsets.left + screenInsets.right);
411 screenBounds.height -=
412 Math.abs(screenInsets.top + screenInsets.bottom);
413 position.x -= Math.abs(screenInsets.left);
414 position.y -= Math.abs(screenInsets.top);
415 }
416
417 Container parent = getParent();
418 if (parent instanceof JPopupMenu) {
419 // We are a submenu (pull-right)
420 int xOffset = UIManager.getInt("Menu.submenuPopupOffsetX");
421 int yOffset = UIManager.getInt("Menu.submenuPopupOffsetY");
422
423 if( SwingUtilities.isLeftToRight(this) ) {
424 // First determine x:
425 x = s.width + xOffset; // Prefer placement to the right
426 if (position.x + x + pmSize.width >= screenBounds.width
427 + screenBounds.x &&
428 // popup doesn't fit - place it wherever there's more room
429 screenBounds.width - s.width < 2*(position.x
430 - screenBounds.x)) {
431
432 x = 0 - xOffset - pmSize.width;
433 }
434 } else {
435 // First determine x:
436 x = 0 - xOffset - pmSize.width; // Prefer placement to the left
437 if (position.x + x < screenBounds.x &&
438 // popup doesn't fit - place it wherever there's more room
439 screenBounds.width - s.width > 2*(position.x -
440 screenBounds.x)) {
441
442 x = s.width + xOffset;
443 }
444 }
445 // Then the y:
446 y = yOffset; // Prefer dropping down
447 if (position.y + y + pmSize.height >= screenBounds.height
448 + screenBounds.y &&
449 // popup doesn't fit - place it wherever there's more room
450 screenBounds.height - s.height < 2*(position.y
451 - screenBounds.y)) {
452
453 y = s.height - yOffset - pmSize.height;
454 }
455 } else {
456 // We are a toplevel menu (pull-down)
457 int xOffset = UIManager.getInt("Menu.menuPopupOffsetX");
458 int yOffset = UIManager.getInt("Menu.menuPopupOffsetY");
459
460 if( SwingUtilities.isLeftToRight(this) ) {
461 // First determine the x:
462 x = xOffset; // Extend to the right
463 if (position.x + x + pmSize.width >= screenBounds.width
464 + screenBounds.x &&
465 // popup doesn't fit - place it wherever there's more room
466 screenBounds.width - s.width < 2*(position.x
467 - screenBounds.x)) {
468
469 x = s.width - xOffset - pmSize.width;
470 }
471 } else {
472 // First determine the x:
473 x = s.width - xOffset - pmSize.width; // Extend to the left
474 if (position.x + x < screenBounds.x &&
475 // popup doesn't fit - place it wherever there's more room
476 screenBounds.width - s.width > 2*(position.x
477 - screenBounds.x)) {
478
479 x = xOffset;
480 }
481 }
482 // Then the y:
483 y = s.height + yOffset; // Prefer dropping down
484 if (position.y + y + pmSize.height >= screenBounds.height &&
485 // popup doesn't fit - place it wherever there's more room
486 screenBounds.height - s.height < 2*(position.y
487 - screenBounds.y)) {
488
489 y = 0 - yOffset - pmSize.height; // Otherwise drop 'up'
490 }
491 }
492 return new Point(x,y);
493 }
494
495
496 /**
497 * Returns the suggested delay, in milliseconds, before submenus
498 * are popped up or down.
499 * Each look and feel (L&F) may determine its own policy for
500 * observing the <code>delay</code> property.
501 * In most cases, the delay is not observed for top level menus
502 * or while dragging. The default for <code>delay</code> is 0.
503 * This method is a property of the look and feel code and is used
504 * to manage the idiosyncracies of the various UI implementations.
505 *
506 *
507 * @return the <code>delay</code> property
508 */
509 public int getDelay() {
510 return delay;
511 }
512
513 /**
514 * Sets the suggested delay before the menu's <code>PopupMenu</code>
515 * is popped up or down. Each look and feel (L&F) may determine
516 * it's own policy for observing the delay property. In most cases,
517 * the delay is not observed for top level menus or while dragging.
518 * This method is a property of the look and feel code and is used
519 * to manage the idiosyncracies of the various UI implementations.
520 *
521 * @param d the number of milliseconds to delay
522 * @exception IllegalArgumentException if <code>d</code>
523 * is less than 0
524 * @beaninfo
525 * description: The delay between menu selection and making the popup menu visible
526 * expert: true
527 */
528 public void setDelay(int d) {
529 if (d < 0)
530 throw new IllegalArgumentException("Delay must be a positive integer");
531
532 delay = d;
533 }
534
535 /**
536 * The window-closing listener for the popup.
537 *
538 * @see WinListener
539 */
540 protected WinListener popupListener;
541
542 private void ensurePopupMenuCreated() {
543 if (popupMenu == null) {
544 final JMenu thisMenu = this;
545 this.popupMenu = new JPopupMenu();
546 popupMenu.setInvoker(this);
547 popupListener = createWinListener(popupMenu);
548 }
549 }
550
551 /*
552 * Return the customized location of the popup component.
553 */
554 private Point getCustomMenuLocation() {
555 return customMenuLocation;
556 }
557
558 /**
559 * Sets the location of the popup component.
560 *
561 * @param x the x coordinate of the popup's new position
562 * @param y the y coordinate of the popup's new position
563 */
564 public void setMenuLocation(int x, int y) {
565 customMenuLocation = new Point(x, y);
566 if (popupMenu != null)
567 popupMenu.setLocation(x, y);
568 }
569
570 /**
571 * Appends a menu item to the end of this menu.
572 * Returns the menu item added.
573 *
574 * @param menuItem the <code>JMenuitem</code> to be added
575 * @return the <code>JMenuItem</code> added
576 */
577 public JMenuItem add(JMenuItem menuItem) {
578 ensurePopupMenuCreated();
579 return popupMenu.add(menuItem);
580 }
581
582 /**
583 * Appends a component to the end of this menu.
584 * Returns the component added.
585 *
586 * @param c the <code>Component</code> to add
587 * @return the <code>Component</code> added
588 */
589 public Component add(Component c) {
590 ensurePopupMenuCreated();
591 popupMenu.add(c);
592 return c;
593 }
594
595 /**
596 * Adds the specified component to this container at the given
597 * position. If <code>index</code> equals -1, the component will
598 * be appended to the end.
599 * @param c the <code>Component</code> to add
600 * @param index the position at which to insert the component
601 * @return the <code>Component</code> added
602 * @see #remove
603 * @see java.awt.Container#add(Component, int)
604 */
605 public Component add(Component c, int index) {
606 ensurePopupMenuCreated();
607 popupMenu.add(c, index);
608 return c;
609 }
610
611 /**
612 * Creates a new menu item with the specified text and appends
613 * it to the end of this menu.
614 *
615 * @param s the string for the menu item to be added
616 */
617 public JMenuItem add(String s) {
618 return add(new JMenuItem(s));
619 }
620
621 /**
622 * Creates a new menu item attached to the specified
623 * <code>Action</code> object and appends it to the end of this menu.
624 *
625 * @param a the <code>Action</code> for the menu item to be added
626 * @see Action
627 */
628 public JMenuItem add(Action a) {
629 JMenuItem mi = createActionComponent(a);
630 mi.setAction(a);
631 add(mi);
632 return mi;
633 }
634
635 /**
636 * Factory method which creates the <code>JMenuItem</code> for
637 * <code>Action</code>s added to the <code>JMenu</code>.
638 *
639 * @param a the <code>Action</code> for the menu item to be added
640 * @return the new menu item
641 * @see Action
642 *
643 * @since 1.3
644 */
645 protected JMenuItem createActionComponent(Action a) {
646 JMenuItem mi = new JMenuItem() {
647 protected PropertyChangeListener createActionPropertyChangeListener(Action a) {
648 PropertyChangeListener pcl = createActionChangeListener(this);
649 if (pcl == null) {
650 pcl = super.createActionPropertyChangeListener(a);
651 }
652 return pcl;
653 }
654 };
655 mi.setHorizontalTextPosition(JButton.TRAILING);
656 mi.setVerticalTextPosition(JButton.CENTER);
657 return mi;
658 }
659
660 /**
661 * Returns a properly configured <code>PropertyChangeListener</code>
662 * which updates the control as changes to the <code>Action</code> occur.
663 */
664 protected PropertyChangeListener createActionChangeListener(JMenuItem b) {
665 return b.createActionPropertyChangeListener0(b.getAction());
666 }
667
668 /**
669 * Appends a new separator to the end of the menu.
670 */
671 public void addSeparator()
672 {
673 ensurePopupMenuCreated();
674 popupMenu.addSeparator();
675 }
676
677 /**
678 * Inserts a new menu item with the specified text at a
679 * given position.
680 *
681 * @param s the text for the menu item to add
682 * @param pos an integer specifying the position at which to add the
683 * new menu item
684 * @exception IllegalArgumentException when the value of
685 * <code>pos</code> < 0
686 */
687 public void insert(String s, int pos) {
688 if (pos < 0) {
689 throw new IllegalArgumentException("index less than zero.");
690 }
691
692 ensurePopupMenuCreated();
693 popupMenu.insert(new JMenuItem(s), pos);
694 }
695
696 /**
697 * Inserts the specified <code>JMenuitem</code> at a given position.
698 *
699 * @param mi the <code>JMenuitem</code> to add
700 * @param pos an integer specifying the position at which to add the
701 * new <code>JMenuitem</code>
702 * @return the new menu item
703 * @exception IllegalArgumentException if the value of
704 * <code>pos</code> < 0
705 */
706 public JMenuItem insert(JMenuItem mi, int pos) {
707 if (pos < 0) {
708 throw new IllegalArgumentException("index less than zero.");
709 }
710 ensurePopupMenuCreated();
711 popupMenu.insert(mi, pos);
712 return mi;
713 }
714
715 /**
716 * Inserts a new menu item attached to the specified <code>Action</code>
717 * object at a given position.
718 *
719 * @param a the <code>Action</code> object for the menu item to add
720 * @param pos an integer specifying the position at which to add the
721 * new menu item
722 * @exception IllegalArgumentException if the value of
723 * <code>pos</code> < 0
724 */
725 public JMenuItem insert(Action a, int pos) {
726 if (pos < 0) {
727 throw new IllegalArgumentException("index less than zero.");
728 }
729
730 ensurePopupMenuCreated();
731 JMenuItem mi = new JMenuItem(a);
732 mi.setHorizontalTextPosition(JButton.TRAILING);
733 mi.setVerticalTextPosition(JButton.CENTER);
734 popupMenu.insert(mi, pos);
735 return mi;
736 }
737
738 /**
739 * Inserts a separator at the specified position.
740 *
741 * @param index an integer specifying the position at which to
742 * insert the menu separator
743 * @exception IllegalArgumentException if the value of
744 * <code>index</code> < 0
745 */
746 public void insertSeparator(int index) {
747 if (index < 0) {
748 throw new IllegalArgumentException("index less than zero.");
749 }
750
751 ensurePopupMenuCreated();
752 popupMenu.insert( new JPopupMenu.Separator(), index );
753 }
754
755 /**
756 * Returns the <code>JMenuItem</code> at the specified position.
757 * If the component at <code>pos</code> is not a menu item,
758 * <code>null</code> is returned.
759 * This method is included for AWT compatibility.
760 *
761 * @param pos an integer specifying the position
762 * @exception IllegalArgumentException if the value of
763 * <code>pos</code> < 0
764 * @return the menu item at the specified position; or <code>null</code>
765 * if the item as the specified position is not a menu item
766 */
767 public JMenuItem getItem(int pos) {
768 if (pos < 0) {
769 throw new IllegalArgumentException("index less than zero.");
770 }
771
772 Component c = getMenuComponent(pos);
773 if (c instanceof JMenuItem) {
774 JMenuItem mi = (JMenuItem) c;
775 return mi;
776 }
777
778 // 4173633
779 return null;
780 }
781
782 /**
783 * Returns the number of items on the menu, including separators.
784 * This method is included for AWT compatibility.
785 *
786 * @return an integer equal to the number of items on the menu
787 * @see #getMenuComponentCount
788 */
789 public int getItemCount() {
790 return getMenuComponentCount();
791 }
792
793 /**
794 * Returns true if the menu can be torn off. This method is not
795 * yet implemented.
796 *
797 * @return true if the menu can be torn off, else false
798 * @exception Error if invoked -- this method is not yet implemented
799 */
800 public boolean isTearOff() {
801 throw new Error("boolean isTearOff() {} not yet implemented");
802 }
803
804 /**
805 * Removes the specified menu item from this menu. If there is no
806 * popup menu, this method will have no effect.
807 *
808 * @param item the <code>JMenuItem</code> to be removed from the menu
809 */
810 public void remove(JMenuItem item) {
811 if (popupMenu != null)
812 popupMenu.remove(item);
813 }
814
815 /**
816 * Removes the menu item at the specified index from this menu.
817 *
818 * @param pos the position of the item to be removed
819 * @exception IllegalArgumentException if the value of
820 * <code>pos</code> < 0, or if <code>pos</code>
821 * is greater than the number of menu items
822 */
823 public void remove(int pos) {
824 if (pos < 0) {
825 throw new IllegalArgumentException("index less than zero.");
826 }
827 if (pos > getItemCount()) {
828 throw new IllegalArgumentException("index greater than the number of items.");
829 }
830 if (popupMenu != null)
831 popupMenu.remove(pos);
832 }
833
834 /**
835 * Removes the component <code>c</code> from this menu.
836 *
837 * @param c the component to be removed
838 */
839 public void remove(Component c) {
840 if (popupMenu != null)
841 popupMenu.remove(c);
842 }
843
844 /**
845 * Removes all menu items from this menu.
846 */
847 public void removeAll() {
848 if (popupMenu != null)
849 popupMenu.removeAll();
850 }
851
852 /**
853 * Returns the number of components on the menu.
854 *
855 * @return an integer containing the number of components on the menu
856 */
857 public int getMenuComponentCount() {
858 int componentCount = 0;
859 if (popupMenu != null)
860 componentCount = popupMenu.getComponentCount();
861 return componentCount;
862 }
863
864 /**
865 * Returns the component at position <code>n</code>.
866 *
867 * @param n the position of the component to be returned
868 * @return the component requested, or <code>null</code>
869 * if there is no popup menu
870 *
871 */
872 public Component getMenuComponent(int n) {
873 if (popupMenu != null)
874 return popupMenu.getComponent(n);
875
876 return null;
877 }
878
879 /**
880 * Returns an array of <code>Component</code>s of the menu's
881 * subcomponents. Note that this returns all <code>Component</code>s
882 * in the popup menu, including separators.
883 *
884 * @return an array of <code>Component</code>s or an empty array
885 * if there is no popup menu
886 */
887 public Component[] getMenuComponents() {
888 if (popupMenu != null)
889 return popupMenu.getComponents();
890
891 return new Component[0];
892 }
893
894 /**
895 * Returns true if the menu is a 'top-level menu', that is, if it is
896 * the direct child of a menubar.
897 *
898 * @return true if the menu is activated from the menu bar;
899 * false if the menu is activated from a menu item
900 * on another menu
901 */
902 public boolean isTopLevelMenu() {
903 if (getParent() instanceof JMenuBar)
904 return true;
905
906 return false;
907 }
908
909 /**
910 * Returns true if the specified component exists in the
911 * submenu hierarchy.
912 *
913 * @param c the <code>Component</code> to be tested
914 * @return true if the <code>Component</code> exists, false otherwise
915 */
916 public boolean isMenuComponent(Component c) {
917 // Are we in the MenuItem part of the menu
918 if (c == this)
919 return true;
920 // Are we in the PopupMenu?
921 if (c instanceof JPopupMenu) {
922 JPopupMenu comp = (JPopupMenu) c;
923 if (comp == this.getPopupMenu())
924 return true;
925 }
926 // Are we in a Component on the PopupMenu
927 int ncomponents = this.getMenuComponentCount();
928 Component[] component = this.getMenuComponents();
929 for (int i = 0 ; i < ncomponents ; i++) {
930 Component comp = component[i];
931 // Are we in the current component?
932 if (comp == c)
933 return true;
934 // Hmmm, what about Non-menu containers?
935
936 // Recursive call for the Menu case
937 if (comp instanceof JMenu) {
938 JMenu subMenu = (JMenu) comp;
939 if (subMenu.isMenuComponent(c))
940 return true;
941 }
942 }
943 return false;
944 }
945
946
947 /*
948 * Returns a point in the coordinate space of this menu's popupmenu
949 * which corresponds to the point <code>p</code> in the menu's
950 * coordinate space.
951 *
952 * @param p the point to be translated
953 * @return the point in the coordinate space of this menu's popupmenu
954 */
955 private Point translateToPopupMenu(Point p) {
956 return translateToPopupMenu(p.x, p.y);
957 }
958
959 /*
960 * Returns a point in the coordinate space of this menu's popupmenu
961 * which corresponds to the point (x,y) in the menu's coordinate space.
962 *
963 * @param x the x coordinate of the point to be translated
964 * @param y the y coordinate of the point to be translated
965 * @return the point in the coordinate space of this menu's popupmenu
966 */
967 private Point translateToPopupMenu(int x, int y) {
968 int newX;
969 int newY;
970
971 if (getParent() instanceof JPopupMenu) {
972 newX = x - getSize().width;
973 newY = y;
974 } else {
975 newX = x;
976 newY = y - getSize().height;
977 }
978
979 return new Point(newX, newY);
980 }
981
982 /**
983 * Returns the popupmenu associated with this menu. If there is
984 * no popupmenu, it will create one.
985 */
986 public JPopupMenu getPopupMenu() {
987 ensurePopupMenuCreated();
988 return popupMenu;
989 }
990
991 /**
992 * Adds a listener for menu events.
993 *
994 * @param l the listener to be added
995 */
996 public void addMenuListener(MenuListener l) {
997 listenerList.add(MenuListener.class, l);
998 }
999
1000 /**
1001 * Removes a listener for menu events.
1002 *
1003 * @param l the listener to be removed
1004 */
1005 public void removeMenuListener(MenuListener l) {
1006 listenerList.remove(MenuListener.class, l);
1007 }
1008
1009 /**
1010 * Returns an array of all the <code>MenuListener</code>s added
1011 * to this JMenu with addMenuListener().
1012 *
1013 * @return all of the <code>MenuListener</code>s added or an empty
1014 * array if no listeners have been added
1015 * @since 1.4
1016 */
1017 public MenuListener[] getMenuListeners() {
1018 return (MenuListener[])listenerList.getListeners(MenuListener.class);
1019 }
1020
1021 /**
1022 * Notifies all listeners that have registered interest for
1023 * notification on this event type. The event instance
1024 * is created lazily.
1025 *
1026 * @exception Error if there is a <code>null</code> listener
1027 * @see EventListenerList
1028 */
1029 protected void fireMenuSelected() {
1030 if (DEBUG) {
1031 System.out.println("In JMenu.fireMenuSelected");
1032 }
1033 // Guaranteed to return a non-null array
1034 Object[] listeners = listenerList.getListenerList();
1035 // Process the listeners last to first, notifying
1036 // those that are interested in this event
1037 for (int i = listeners.length-2; i>=0; i-=2) {
1038 if (listeners[i]==MenuListener.class) {
1039 if (listeners[i+1]== null) {
1040 throw new Error(getText() +" has a NULL Listener!! " + i);
1041 } else {
1042 // Lazily create the event:
1043 if (menuEvent == null)
1044 menuEvent = new MenuEvent(this);
1045 ((MenuListener)listeners[i+1]).menuSelected(menuEvent);
1046 }
1047 }
1048 }
1049 }
1050
1051 /**
1052 * Notifies all listeners that have registered interest for
1053 * notification on this event type. The event instance
1054 * is created lazily.
1055 *
1056 * @exception Error if there is a <code>null</code> listener
1057 * @see EventListenerList
1058 */
1059 protected void fireMenuDeselected() {
1060 if (DEBUG) {
1061 System.out.println("In JMenu.fireMenuDeselected");
1062 }
1063 // Guaranteed to return a non-null array
1064 Object[] listeners = listenerList.getListenerList();
1065 // Process the listeners last to first, notifying
1066 // those that are interested in this event
1067 for (int i = listeners.length-2; i>=0; i-=2) {
1068 if (listeners[i]==MenuListener.class) {
1069 if (listeners[i+1]== null) {
1070 throw new Error(getText() +" has a NULL Listener!! " + i);
1071 } else {
1072 // Lazily create the event:
1073 if (menuEvent == null)
1074 menuEvent = new MenuEvent(this);
1075 ((MenuListener)listeners[i+1]).menuDeselected(menuEvent);
1076 }
1077 }
1078 }
1079 }
1080
1081 /**
1082 * Notifies all listeners that have registered interest for
1083 * notification on this event type. The event instance
1084 * is created lazily.
1085 *
1086 * @exception Error if there is a <code>null</code> listener
1087 * @see EventListenerList
1088 */
1089 protected void fireMenuCanceled() {
1090 if (DEBUG) {
1091 System.out.println("In JMenu.fireMenuCanceled");
1092 }
1093 // Guaranteed to return a non-null array
1094 Object[] listeners = listenerList.getListenerList();
1095 // Process the listeners last to first, notifying
1096 // those that are interested in this event
1097 for (int i = listeners.length-2; i>=0; i-=2) {
1098 if (listeners[i]==MenuListener.class) {
1099 if (listeners[i+1]== null) {
1100 throw new Error(getText() +" has a NULL Listener!! "
1101 + i);
1102 } else {
1103 // Lazily create the event:
1104 if (menuEvent == null)
1105 menuEvent = new MenuEvent(this);
1106 ((MenuListener)listeners[i+1]).menuCanceled(menuEvent);
1107 }
1108 }
1109 }
1110 }
1111
1112 // Overriden to do nothing, JMenu doesn't support an accelerator
1113 void configureAcceleratorFromAction(Action a) {
1114 }
1115
1116 class MenuChangeListener implements ChangeListener, Serializable {
1117 boolean isSelected = false;
1118 public void stateChanged(ChangeEvent e) {
1119 ButtonModel model = (ButtonModel) e.getSource();
1120 boolean modelSelected = model.isSelected();
1121
1122 if (modelSelected != isSelected) {
1123 if (modelSelected == true) {
1124 fireMenuSelected();
1125 } else {
1126 fireMenuDeselected();
1127 }
1128 isSelected = modelSelected;
1129 }
1130 }
1131 }
1132
1133 private ChangeListener createMenuChangeListener() {
1134 return new MenuChangeListener();
1135 }
1136
1137
1138 /**
1139 * Creates a window-closing listener for the popup.
1140 *
1141 * @param p the <code>JPopupMenu</code>
1142 * @return the new window-closing listener
1143 *
1144 * @see WinListener
1145 */
1146 protected WinListener createWinListener(JPopupMenu p) {
1147 return new WinListener(p);
1148 }
1149
1150 /**
1151 * A listener class that watches for a popup window closing.
1152 * When the popup is closing, the listener deselects the menu.
1153 * <p>
1154 * <strong>Warning:</strong>
1155 * Serialized objects of this class will not be compatible with
1156 * future Swing releases. The current serialization support is
1157 * appropriate for short term storage or RMI between applications running
1158 * the same version of Swing. As of 1.4, support for long term storage
1159 * of all JavaBeans<sup><font size="-2">TM</font></sup>
1160 * has been added to the <code>java.beans</code> package.
1161 * Please see {@link java.beans.XMLEncoder}.
1162 */
1163 protected class WinListener extends WindowAdapter implements Serializable {
1164 JPopupMenu popupMenu;
1165 /**
1166 * Create the window listener for the specified popup.
1167 * @since 1.4
1168 */
1169 public WinListener(JPopupMenu p) {
1170 this.popupMenu = p;
1171 }
1172 /**
1173 * Deselect the menu when the popup is closed from outside.
1174 */
1175 public void windowClosing(WindowEvent e) {
1176 setSelected(false);
1177 }
1178 }
1179
1180 /**
1181 * Messaged when the menubar selection changes to activate or
1182 * deactivate this menu.
1183 * Overrides <code>JMenuItem.menuSelectionChanged</code>.
1184 *
1185 * @param isIncluded true if this menu is active, false if
1186 * it is not
1187 */
1188 public void menuSelectionChanged(boolean isIncluded) {
1189 if (DEBUG) {
1190 System.out.println("In JMenu.menuSelectionChanged to " + isIncluded);
1191 }
1192 setSelected(isIncluded);
1193 }
1194
1195 /**
1196 * Returns an array of <code>MenuElement</code>s containing the submenu
1197 * for this menu component. If popup menu is <code>null</code> returns
1198 * an empty array. This method is required to conform to the
1199 * <code>MenuElement</code> interface. Note that since
1200 * <code>JSeparator</code>s do not conform to the <code>MenuElement</code>
1201 * interface, this array will only contain <code>JMenuItem</code>s.
1202 *
1203 * @return an array of <code>MenuElement</code> objects
1204 */
1205 public MenuElement[] getSubElements() {
1206 if(popupMenu == null)
1207 return new MenuElement[0];
1208 else {
1209 MenuElement result[] = new MenuElement[1];
1210 result[0] = popupMenu;
1211 return result;
1212 }
1213 }
1214
1215
1216 // implements javax.swing.MenuElement
1217 /**
1218 * Returns the <code>java.awt.Component</code> used to
1219 * paint this <code>MenuElement</code>.
1220 * The returned component is used to convert events and detect if
1221 * an event is inside a menu component.
1222 */
1223 public Component getComponent() {
1224 return this;
1225 }
1226
1227
1228 /**
1229 * Sets the <code>ComponentOrientation</code> property of this menu
1230 * and all components contained within it. This includes all
1231 * components returned by {@link #getMenuComponents getMenuComponents}.
1232 *
1233 * @param o the new component orientation of this menu and
1234 * the components contained within it.
1235 * @exception NullPointerException if <code>orientation</code> is null.
1236 * @see java.awt.Component#setComponentOrientation
1237 * @see java.awt.Component#getComponentOrientation
1238 * @since 1.4
1239 */
1240 public void applyComponentOrientation(ComponentOrientation o) {
1241 super.applyComponentOrientation(o);
1242
1243 if ( popupMenu != null ) {
1244 int ncomponents = getMenuComponentCount();
1245 for (int i = 0 ; i < ncomponents ; ++i) {
1246 getMenuComponent(i).applyComponentOrientation(o);
1247 }
1248 popupMenu.setComponentOrientation(o);
1249 }
1250 }
1251
1252 public void setComponentOrientation(ComponentOrientation o) {
1253 super.setComponentOrientation(o);
1254 if ( popupMenu != null ) {
1255 popupMenu.setComponentOrientation(o);
1256 }
1257 }
1258
1259 /**
1260 * <code>setAccelerator</code> is not defined for <code>JMenu</code>.
1261 * Use <code>setMnemonic</code> instead.
1262 * @param keyStroke the keystroke combination which will invoke
1263 * the <code>JMenuItem</code>'s actionlisteners
1264 * without navigating the menu hierarchy
1265 * @exception Error if invoked -- this method is not defined for JMenu.
1266 * Use <code>setMnemonic</code> instead
1267 *
1268 * @beaninfo
1269 * description: The keystroke combination which will invoke the JMenuItem's
1270 * actionlisteners without navigating the menu hierarchy
1271 * hidden: true
1272 */
1273 public void setAccelerator(KeyStroke keyStroke) {
1274 throw new Error("setAccelerator() is not defined for JMenu. Use setMnemonic() instead.");
1275 }
1276
1277 /**
1278 * Processes key stroke events such as mnemonics and accelerators.
1279 *
1280 * @param evt the key event to be processed
1281 */
1282 protected void processKeyEvent(KeyEvent evt) {
1283 MenuSelectionManager.defaultManager().processKeyEvent(evt);
1284 if (evt.isConsumed())
1285 return;
1286
1287 super.processKeyEvent(evt);
1288 }
1289
1290 /**
1291 * Programmatically performs a "click". This overrides the method
1292 * <code>AbstractButton.doClick</code> in order to make the menu pop up.
1293 * @param pressTime indicates the number of milliseconds the
1294 * button was pressed for
1295 */
1296 public void doClick(int pressTime) {
1297 MenuElement me[] = buildMenuElementArray(this);
1298 MenuSelectionManager.defaultManager().setSelectedPath(me);
1299 }
1300
1301 /*
1302 * Build an array of menu elements - from <code>PopupMenu</code> to
1303 * the root <code>JMenuBar</code>.
1304 * @param leaf the leaf node from which to start building up the array
1305 * @return the array of menu items
1306 */
1307 private MenuElement[] buildMenuElementArray(JMenu leaf) {
1308 Vector elements = new Vector();
1309 Component current = leaf.getPopupMenu();
1310 JPopupMenu pop;
1311 JMenu menu;
1312 JMenuBar bar;
1313
1314 while (true) {
1315 if (current instanceof JPopupMenu) {
1316 pop = (JPopupMenu) current;
1317 elements.insertElementAt(pop, 0);
1318 current = pop.getInvoker();
1319 } else if (current instanceof JMenu) {
1320 menu = (JMenu) current;
1321 elements.insertElementAt(menu, 0);
1322 current = menu.getParent();
1323 } else if (current instanceof JMenuBar) {
1324 bar = (JMenuBar) current;
1325 elements.insertElementAt(bar, 0);
1326 MenuElement me[] = new MenuElement[elements.size()];
1327 elements.copyInto(me);
1328 return me;
1329 }
1330 }
1331 }
1332
1333
1334 /**
1335 * See <code>readObject</code> and <code>writeObject</code> in
1336 * <code>JComponent</code> for more
1337 * information about serialization in Swing.
1338 */
1339 private void writeObject(ObjectOutputStream s) throws IOException {
1340 s.defaultWriteObject();
1341 if (getUIClassID().equals(uiClassID)) {
1342 byte count = JComponent.getWriteObjCounter(this);
1343 JComponent.setWriteObjCounter(this, --count);
1344 if (count == 0 && ui != null) {
1345 ui.installUI(this);
1346 }
1347 }
1348 }
1349
1350
1351 /**
1352 * Returns a string representation of this <code>JMenu</code>. This
1353 * method is intended to be used only for debugging purposes, and the
1354 * content and format of the returned string may vary between
1355 * implementations. The returned string may be empty but may not
1356 * be <code>null</code>.
1357 *
1358 * @return a string representation of this JMenu.
1359 */
1360 protected String paramString() {
1361 return super.paramString();
1362 }
1363
1364
1365 /////////////////
1366 // Accessibility support
1367 ////////////////
1368
1369 /**
1370 * Gets the AccessibleContext associated with this JMenu.
1371 * For JMenus, the AccessibleContext takes the form of an
1372 * AccessibleJMenu.
1373 * A new AccessibleJMenu instance is created if necessary.
1374 *
1375 * @return an AccessibleJMenu that serves as the
1376 * AccessibleContext of this JMenu
1377 */
1378 public AccessibleContext getAccessibleContext() {
1379 if (accessibleContext == null) {
1380 accessibleContext = new AccessibleJMenu();
1381 }
1382 return accessibleContext;
1383 }
1384
1385 /**
1386 * This class implements accessibility support for the
1387 * <code>JMenu</code> class. It provides an implementation of the
1388 * Java Accessibility API appropriate to menu user-interface elements.
1389 * <p>
1390 * <strong>Warning:</strong>
1391 * Serialized objects of this class will not be compatible with
1392 * future Swing releases. The current serialization support is
1393 * appropriate for short term storage or RMI between applications running
1394 * the same version of Swing. As of 1.4, support for long term storage
1395 * of all JavaBeans<sup><font size="-2">TM</font></sup>
1396 * has been added to the <code>java.beans</code> package.
1397 * Please see {@link java.beans.XMLEncoder}.
1398 */
1399 protected class AccessibleJMenu extends AccessibleJMenuItem
1400 implements AccessibleSelection {
1401
1402 /**
1403 * Returns the number of accessible children in the object. If all
1404 * of the children of this object implement Accessible, than this
1405 * method should return the number of children of this object.
1406 *
1407 * @return the number of accessible children in the object.
1408 */
1409 public int getAccessibleChildrenCount() {
1410 Component[] children = getMenuComponents();
1411 int count = 0;
1412 for (int j = 0; j < children.length; j++) {
1413 if (children[j] instanceof Accessible) {
1414 count++;
1415 }
1416 }
1417 return count;
1418 }
1419
1420 /**
1421 * Returns the nth Accessible child of the object.
1422 *
1423 * @param i zero-based index of child
1424 * @return the nth Accessible child of the object
1425 */
1426 public Accessible getAccessibleChild(int i) {
1427 Component[] children = getMenuComponents();
1428 int count = 0;
1429 for (int j = 0; j < children.length; j++) {
1430 if (children[j] instanceof Accessible) {
1431 if (count == i) {
1432 if (children[j] instanceof JComponent) {
1433 // FIXME: [[[WDW - probably should set this when
1434 // the component is added to the menu. I tried
1435 // to do this in most cases, but the separators
1436 // added by addSeparator are hard to get to.]]]
1437 AccessibleContext ac = ((Accessible) children[j]).getAccessibleContext();
1438 ac.setAccessibleParent(JMenu.this);
1439 }
1440 return (Accessible) children[j];
1441 } else {
1442 count++;
1443 }
1444 }
1445 }
1446 return null;
1447 }
1448
1449 /**
1450 * Get the role of this object.
1451 *
1452 * @return an instance of AccessibleRole describing the role of the
1453 * object
1454 * @see AccessibleRole
1455 */
1456 public AccessibleRole getAccessibleRole() {
1457 return AccessibleRole.MENU;
1458 }
1459
1460 /**
1461 * Get the AccessibleSelection associated with this object. In the
1462 * implementation of the Java Accessibility API for this class,
1463 * return this object, which is responsible for implementing the
1464 * AccessibleSelection interface on behalf of itself.
1465 *
1466 * @return this object
1467 */
1468 public AccessibleSelection getAccessibleSelection() {
1469 return this;
1470 }
1471
1472 /**
1473 * Returns 1 if a sub-menu is currently selected in this menu.
1474 *
1475 * @return 1 if a menu is currently selected, else 0
1476 */
1477 public int getAccessibleSelectionCount() {
1478 MenuElement me[] =
1479 MenuSelectionManager.defaultManager().getSelectedPath();
1480 if (me != null) {
1481 for (int i = 0; i < me.length; i++) {
1482 if (me[i] == JMenu.this) { // this menu is selected
1483 if (i+1 < me.length) {
1484 return 1;
1485 }
1486 }
1487 }
1488 }
1489 return 0;
1490 }
1491
1492 /**
1493 * Returns the currently selected sub-menu if one is selected,
1494 * otherwise null (there can only be one selection, and it can
1495 * only be a sub-menu, as otherwise menu items don't remain
1496 * selected).
1497 */
1498 public Accessible getAccessibleSelection(int i) {
1499 // if i is a sub-menu & popped, return it
1500 if (i < 0 || i >= getItemCount()) {
1501 return null;
1502 }
1503 MenuElement me[] =
1504 MenuSelectionManager.defaultManager().getSelectedPath();
1505 if (me != null) {
1506 for (int j = 0; j < me.length; j++) {
1507 if (me[j] == JMenu.this) { // this menu is selected
1508 // so find the next JMenuItem in the MenuElement
1509 // array, and return it!
1510 while (++j < me.length) {
1511 if (me[j] instanceof JMenuItem) {
1512 return (Accessible) me[j];
1513 }
1514 }
1515 }
1516 }
1517 }
1518 return null;
1519 }
1520
1521 /**
1522 * Returns true if the current child of this object is selected
1523 * (that is, if this child is a popped-up submenu).
1524 *
1525 * @param i the zero-based index of the child in this Accessible
1526 * object.
1527 * @see AccessibleContext#getAccessibleChild
1528 */
1529 public boolean isAccessibleChildSelected(int i) {
1530 // if i is a sub-menu and is pop-ed up, return true, else false
1531 MenuElement me[] =
1532 MenuSelectionManager.defaultManager().getSelectedPath();
1533 if (me != null) {
1534 JMenuItem mi = JMenu.this.getItem(i);
1535 for (int j = 0; j < me.length; j++) {
1536 if (me[j] == mi) {
1537 return true;
1538 }
1539 }
1540 }
1541 return false;
1542 }
1543
1544
1545 /**
1546 * Selects the <code>i</code>th menu in the menu.
1547 * If that item is a submenu,
1548 * it will pop up in response. If a different item is already
1549 * popped up, this will force it to close. If this is a sub-menu
1550 * that is already popped up (selected), this method has no
1551 * effect.
1552 *
1553 * @param i the index of the item to be selected
1554 * @see #getAccessibleStateSet
1555 */
1556 public void addAccessibleSelection(int i) {
1557 if (i < 0 || i >= getItemCount()) {
1558 return;
1559 }
1560 JMenuItem mi = getItem(i);
1561 if (mi != null) {
1562 if (mi instanceof JMenu) {
1563 MenuElement me[] = buildMenuElementArray((JMenu) mi);
1564 MenuSelectionManager.defaultManager().setSelectedPath(me);
1565 } else {
1566 MenuSelectionManager.defaultManager().setSelectedPath(null);
1567 }
1568 }
1569 }
1570
1571 /**
1572 * Removes the nth item from the selection. In general, menus
1573 * can only have one item within them selected at a time
1574 * (e.g. one sub-menu popped open).
1575 *
1576 * @param i the zero-based index of the selected item
1577 */
1578 public void removeAccessibleSelection(int i) {
1579 if (i < 0 || i >= getItemCount()) {
1580 return;
1581 }
1582 JMenuItem mi = getItem(i);
1583 if (mi != null && mi instanceof JMenu) {
1584 if (((JMenu) mi).isSelected()) {
1585 MenuElement old[] =
1586 MenuSelectionManager.defaultManager().getSelectedPath();
1587 MenuElement me[] = new MenuElement[old.length-2];
1588 for (int j = 0; j < old.length -2; j++) {
1589 me[j] = old[j];
1590 }
1591 MenuSelectionManager.defaultManager().setSelectedPath(me);
1592 }
1593 }
1594 }
1595
1596 /**
1597 * Clears the selection in the object, so that nothing in the
1598 * object is selected. This will close any open sub-menu.
1599 */
1600 public void clearAccessibleSelection() {
1601 // if this menu is selected, reset selection to only go
1602 // to this menu; else do nothing
1603 MenuElement old[] =
1604 MenuSelectionManager.defaultManager().getSelectedPath();
1605 if (old != null) {
1606 for (int j = 0; j < old.length; j++) {
1607 if (old[j] == JMenu.this) { // menu is in the selection!
1608 MenuElement me[] = new MenuElement[j+1];
1609 System.arraycopy(old, 0, me, 0, j);
1610 me[j] = JMenu.this.getPopupMenu();
1611 MenuSelectionManager.defaultManager().setSelectedPath(me);
1612 }
1613 }
1614 }
1615 }
1616
1617 /**
1618 * Normally causes every selected item in the object to be selected
1619 * if the object supports multiple selections. This method
1620 * makes no sense in a menu bar, and so does nothing.
1621 */
1622 public void selectAllAccessibleSelection() {
1623 }
1624 } // inner class AccessibleJMenu
1625
1626 }
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