1 /*
2 * Copyright (c) 1995, 2016, Oracle and/or its affiliates. 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. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.awt;
27
28 import java.awt.event.ActionEvent;
29 import java.awt.peer.MenuComponentPeer;
30 import java.io.IOException;
31 import java.io.ObjectInputStream;
32 import java.security.AccessControlContext;
33 import java.security.AccessController;
34
35 import javax.accessibility.Accessible;
36 import javax.accessibility.AccessibleComponent;
37 import javax.accessibility.AccessibleContext;
38 import javax.accessibility.AccessibleRole;
39 import javax.accessibility.AccessibleSelection;
40 import javax.accessibility.AccessibleState;
41 import javax.accessibility.AccessibleStateSet;
42
43 import sun.awt.AWTAccessor;
44 import sun.awt.AppContext;
45 import sun.awt.ComponentFactory;
46
47 /**
48 * The abstract class {@code MenuComponent} is the superclass
49 * of all menu-related components. In this respect, the class
50 * {@code MenuComponent} is analogous to the abstract superclass
51 * {@code Component} for AWT components.
52 * <p>
53 * Menu components receive and process AWT events, just as components do,
54 * through the method {@code processEvent}.
55 *
56 * @author Arthur van Hoff
57 * @since 1.0
58 */
59 public abstract class MenuComponent implements java.io.Serializable {
60
61 static {
62 /* ensure that the necessary native libraries are loaded */
63 Toolkit.loadLibraries();
64 if (!GraphicsEnvironment.isHeadless()) {
65 initIDs();
66 }
67 }
68
69 transient volatile MenuComponentPeer peer;
70 transient volatile MenuContainer parent;
71
72 /**
73 * The {@code AppContext} of the {@code MenuComponent}.
74 * This is set in the constructor and never changes.
75 */
76 private transient volatile AppContext appContext;
77
78 /**
79 * The menu component's font. This value can be
80 * {@code null} at which point a default will be used.
81 * This defaults to {@code null}.
82 *
83 * @serial
84 * @see #setFont(Font)
85 * @see #getFont()
86 */
87 private volatile Font font;
88
89 /**
90 * The menu component's name, which defaults to {@code null}.
91 * @serial
92 * @see #getName()
93 * @see #setName(String)
94 */
95 private volatile String name;
96
97 /**
98 * A variable to indicate whether a name is explicitly set.
99 * If {@code true} the name will be set explicitly.
100 * This defaults to {@code false}.
101 * @serial
102 * @see #setName(String)
103 */
104 private volatile boolean nameExplicitlySet;
105
106 /**
107 * Defaults to {@code false}.
108 * @serial
109 * @see #dispatchEvent(AWTEvent)
110 */
111 volatile boolean newEventsOnly;
112
113 /*
114 * The menu's AccessControlContext.
115 */
116 private transient volatile AccessControlContext acc =
117 AccessController.getContext();
118
119 /*
120 * Returns the acc this menu component was constructed with.
121 */
122 final AccessControlContext getAccessControlContext() {
123 if (acc == null) {
124 throw new SecurityException(
125 "MenuComponent is missing AccessControlContext");
126 }
127 return acc;
128 }
129
130 /*
131 * Internal constants for serialization.
132 */
133 static final String actionListenerK = Component.actionListenerK;
134 static final String itemListenerK = Component.itemListenerK;
135
136 /*
137 * JDK 1.1 serialVersionUID
138 */
139 private static final long serialVersionUID = -4536902356223894379L;
140
141 static {
142 AWTAccessor.setMenuComponentAccessor(
143 new AWTAccessor.MenuComponentAccessor() {
144 @Override
145 public AppContext getAppContext(MenuComponent menuComp) {
146 return menuComp.appContext;
147 }
148 @Override
149 public void setAppContext(MenuComponent menuComp,
150 AppContext appContext) {
151 menuComp.appContext = appContext;
152 }
153 @Override
154 @SuppressWarnings("unchecked")
155 public <T extends MenuComponentPeer> T getPeer(MenuComponent menuComp) {
156 return (T) menuComp.peer;
157 }
158 @Override
159 public MenuContainer getParent(MenuComponent menuComp) {
160 return menuComp.parent;
161 }
162 @Override
163 public void setParent(MenuComponent menuComp, MenuContainer menuContainer) {
164 menuComp.parent = menuContainer;
165 }
166 @Override
167 public Font getFont_NoClientCode(MenuComponent menuComp) {
168 return menuComp.getFont_NoClientCode();
169 }
170 });
171 }
172
173 /**
174 * Creates a {@code MenuComponent}.
175 * @exception HeadlessException if
176 * {@code GraphicsEnvironment.isHeadless}
177 * returns {@code true}
178 * @see java.awt.GraphicsEnvironment#isHeadless
179 */
180 public MenuComponent() throws HeadlessException {
181 GraphicsEnvironment.checkHeadless();
182 appContext = AppContext.getAppContext();
183 }
184
185 /**
186 * Constructs a name for this {@code MenuComponent}.
187 * Called by {@code getName} when the name is {@code null}.
188 * @return a name for this {@code MenuComponent}
189 */
190 String constructComponentName() {
191 return null; // For strict compliance with prior platform versions, a MenuComponent
192 // that doesn't set its name should return null from
193 // getName()
194 }
195
196 final ComponentFactory getComponentFactory() {
197 final Toolkit toolkit = Toolkit.getDefaultToolkit();
198 if (toolkit instanceof ComponentFactory) {
199 return (ComponentFactory) toolkit;
200 }
201 throw new AWTError("UI components are unsupported by: " + toolkit);
202 }
203
204 /**
205 * Gets the name of the menu component.
206 * @return the name of the menu component
207 * @see java.awt.MenuComponent#setName(java.lang.String)
208 * @since 1.1
209 */
210 public String getName() {
211 if (name == null && !nameExplicitlySet) {
212 synchronized(this) {
213 if (name == null && !nameExplicitlySet)
214 name = constructComponentName();
215 }
216 }
217 return name;
218 }
219
220 /**
221 * Sets the name of the component to the specified string.
222 * @param name the name of the menu component
223 * @see java.awt.MenuComponent#getName
224 * @since 1.1
225 */
226 public void setName(String name) {
227 synchronized(this) {
228 this.name = name;
229 nameExplicitlySet = true;
230 }
231 }
232
233 /**
234 * Returns the parent container for this menu component.
235 * @return the menu component containing this menu component,
236 * or {@code null} if this menu component
237 * is the outermost component, the menu bar itself
238 */
239 public MenuContainer getParent() {
240 return getParent_NoClientCode();
241 }
242 // NOTE: This method may be called by privileged threads.
243 // This functionality is implemented in a package-private method
244 // to insure that it cannot be overridden by client subclasses.
245 // DO NOT INVOKE CLIENT CODE ON THIS THREAD!
246 final MenuContainer getParent_NoClientCode() {
247 return parent;
248 }
249
250 /**
251 * Gets the font used for this menu component.
252 * @return the font used in this menu component, if there is one;
253 * {@code null} otherwise
254 * @see java.awt.MenuComponent#setFont
255 */
256 public Font getFont() {
257 Font font = this.font;
258 if (font != null) {
259 return font;
260 }
261 MenuContainer parent = this.parent;
262 if (parent != null) {
263 return parent.getFont();
264 }
265 return null;
266 }
267
268 // NOTE: This method may be called by privileged threads.
269 // This functionality is implemented in a package-private method
270 // to insure that it cannot be overridden by client subclasses.
271 // DO NOT INVOKE CLIENT CODE ON THIS THREAD!
272 final Font getFont_NoClientCode() {
273 Font font = this.font;
274 if (font != null) {
275 return font;
276 }
277
278 // The MenuContainer interface does not have getFont_NoClientCode()
279 // and it cannot, because it must be package-private. Because of
280 // this, we must manually cast classes that implement
281 // MenuContainer.
282 Object parent = this.parent;
283 if (parent != null) {
284 if (parent instanceof Component) {
285 font = ((Component)parent).getFont_NoClientCode();
286 } else if (parent instanceof MenuComponent) {
287 font = ((MenuComponent)parent).getFont_NoClientCode();
288 }
289 }
290 return font;
291 } // getFont_NoClientCode()
292
293
294 /**
295 * Sets the font to be used for this menu component to the specified
296 * font. This font is also used by all subcomponents of this menu
297 * component, unless those subcomponents specify a different font.
298 * <p>
299 * Some platforms may not support setting of all font attributes
300 * of a menu component; in such cases, calling {@code setFont}
301 * will have no effect on the unsupported font attributes of this
302 * menu component. Unless subcomponents of this menu component
303 * specify a different font, this font will be used by those
304 * subcomponents if supported by the underlying platform.
305 *
306 * @param f the font to be set
307 * @see #getFont
308 * @see Font#getAttributes
309 * @see java.awt.font.TextAttribute
310 */
311 public void setFont(Font f) {
312 synchronized (getTreeLock()) {
313 font = f;
314 //Fixed 6312943: NullPointerException in method MenuComponent.setFont(Font)
315 MenuComponentPeer peer = this.peer;
316 if (peer != null) {
317 peer.setFont(f);
318 }
319 }
320 }
321
322 /**
323 * Removes the menu component's peer. The peer allows us to modify the
324 * appearance of the menu component without changing the functionality of
325 * the menu component.
326 */
327 public void removeNotify() {
328 synchronized (getTreeLock()) {
329 MenuComponentPeer p = this.peer;
330 if (p != null) {
331 Toolkit.getEventQueue().removeSourceEvents(this, true);
332 this.peer = null;
333 p.dispose();
334 }
335 }
336 }
337
338 /**
339 * Posts the specified event to the menu.
340 * This method is part of the Java 1.0 event system
341 * and it is maintained only for backwards compatibility.
342 * Its use is discouraged, and it may not be supported
343 * in the future.
344 * @param evt the event which is to take place
345 * @return unconditionally returns false
346 * @deprecated As of JDK version 1.1, replaced by {@link
347 * #dispatchEvent(AWTEvent) dispatchEvent}.
348 */
349 @Deprecated
350 public boolean postEvent(Event evt) {
351 MenuContainer parent = this.parent;
352 if (parent != null) {
353 parent.postEvent(evt);
354 }
355 return false;
356 }
357
358 /**
359 * Delivers an event to this component or one of its sub components.
360 * @param e the event
361 */
362 public final void dispatchEvent(AWTEvent e) {
363 dispatchEventImpl(e);
364 }
365
366 void dispatchEventImpl(AWTEvent e) {
367 EventQueue.setCurrentEventAndMostRecentTime(e);
368
369 Toolkit.getDefaultToolkit().notifyAWTEventListeners(e);
370
371 if (newEventsOnly ||
372 (parent != null && parent instanceof MenuComponent &&
373 ((MenuComponent)parent).newEventsOnly)) {
374 if (eventEnabled(e)) {
375 processEvent(e);
376 } else if (e instanceof ActionEvent && parent != null) {
377 e.setSource(parent);
378 ((MenuComponent)parent).dispatchEvent(e);
379 }
380
381 } else { // backward compatibility
382 @SuppressWarnings("deprecation")
383 Event olde = e.convertToOld();
384 if (olde != null) {
385 postEvent(olde);
386 }
387 }
388 }
389
390 // REMIND: remove when filtering is done at lower level
391 boolean eventEnabled(AWTEvent e) {
392 return false;
393 }
394 /**
395 * Processes events occurring on this menu component.
396 * <p>Note that if the event parameter is {@code null}
397 * the behavior is unspecified and may result in an
398 * exception.
399 *
400 * @param e the event
401 * @since 1.1
402 */
403 protected void processEvent(AWTEvent e) {
404 }
405
406 /**
407 * Returns a string representing the state of this
408 * {@code MenuComponent}. This method is intended to be used
409 * only for debugging purposes, and the content and format of the
410 * returned string may vary between implementations. The returned
411 * string may be empty but may not be {@code null}.
412 *
413 * @return the parameter string of this menu component
414 */
415 protected String paramString() {
416 String thisName = getName();
417 return (thisName != null? thisName : "");
418 }
419
420 /**
421 * Returns a representation of this menu component as a string.
422 * @return a string representation of this menu component
423 */
424 public String toString() {
425 return getClass().getName() + "[" + paramString() + "]";
426 }
427
428 /**
429 * Gets this component's locking object (the object that owns the thread
430 * synchronization monitor) for AWT component-tree and layout
431 * operations.
432 * @return this component's locking object
433 */
434 protected final Object getTreeLock() {
435 return Component.LOCK;
436 }
437
438 /**
439 * Reads the menu component from an object input stream.
440 *
441 * @param s the {@code ObjectInputStream} to read
442 * @exception HeadlessException if
443 * {@code GraphicsEnvironment.isHeadless} returns
444 * {@code true}
445 * @serial
446 * @see java.awt.GraphicsEnvironment#isHeadless
447 */
448 private void readObject(ObjectInputStream s)
449 throws ClassNotFoundException, IOException, HeadlessException
450 {
451 GraphicsEnvironment.checkHeadless();
452
453 acc = AccessController.getContext();
454
455 s.defaultReadObject();
456
457 appContext = AppContext.getAppContext();
458 }
459
460 /**
461 * Initialize JNI field and method IDs.
462 */
463 private static native void initIDs();
464
465
466 /*
467 * --- Accessibility Support ---
468 *
469 * MenuComponent will contain all of the methods in interface Accessible,
470 * though it won't actually implement the interface - that will be up
471 * to the individual objects which extend MenuComponent.
472 */
473
474 AccessibleContext accessibleContext = null;
475
476 /**
477 * Gets the {@code AccessibleContext} associated with
478 * this {@code MenuComponent}.
479 *
480 * The method implemented by this base class returns {@code null}.
481 * Classes that extend {@code MenuComponent}
482 * should implement this method to return the
483 * {@code AccessibleContext} associated with the subclass.
484 *
485 * @return the {@code AccessibleContext} of this
486 * {@code MenuComponent}
487 * @since 1.3
488 */
489 public AccessibleContext getAccessibleContext() {
490 return accessibleContext;
491 }
492
493 /**
494 * Inner class of {@code MenuComponent} used to provide
495 * default support for accessibility. This class is not meant
496 * to be used directly by application developers, but is instead
497 * meant only to be subclassed by menu component developers.
498 * <p>
499 * The class used to obtain the accessible role for this object.
500 * @since 1.3
501 */
502 protected abstract class AccessibleAWTMenuComponent
503 extends AccessibleContext
504 implements java.io.Serializable, AccessibleComponent,
505 AccessibleSelection
506 {
507 /*
508 * JDK 1.3 serialVersionUID
509 */
510 private static final long serialVersionUID = -4269533416223798698L;
511
512 /**
513 * Although the class is abstract, this should be called by
514 * all sub-classes.
515 */
516 protected AccessibleAWTMenuComponent() {
517 }
518
519 // AccessibleContext methods
520 //
521
522 /**
523 * Gets the {@code AccessibleSelection} associated with this
524 * object which allows its {@code Accessible} children to be selected.
525 *
526 * @return {@code AccessibleSelection} if supported by object;
527 * else return {@code null}
528 * @see AccessibleSelection
529 */
530 public AccessibleSelection getAccessibleSelection() {
531 return this;
532 }
533
534 /**
535 * Gets the accessible name of this object. This should almost never
536 * return {@code java.awt.MenuComponent.getName}, as that
537 * generally isn't a localized name, and doesn't have meaning for the
538 * user. If the object is fundamentally a text object (e.g. a menu item), the
539 * accessible name should be the text of the object (e.g. "save").
540 * If the object has a tooltip, the tooltip text may also be an
541 * appropriate String to return.
542 *
543 * @return the localized name of the object -- can be {@code null}
544 * if this object does not have a name
545 * @see AccessibleContext#setAccessibleName
546 */
547 public String getAccessibleName() {
548 return accessibleName;
549 }
550
551 /**
552 * Gets the accessible description of this object. This should be
553 * a concise, localized description of what this object is - what
554 * is its meaning to the user. If the object has a tooltip, the
555 * tooltip text may be an appropriate string to return, assuming
556 * it contains a concise description of the object (instead of just
557 * the name of the object - e.g. a "Save" icon on a toolbar that
558 * had "save" as the tooltip text shouldn't return the tooltip
559 * text as the description, but something like "Saves the current
560 * text document" instead).
561 *
562 * @return the localized description of the object -- can be
563 * {@code null} if this object does not have a description
564 * @see AccessibleContext#setAccessibleDescription
565 */
566 public String getAccessibleDescription() {
567 return accessibleDescription;
568 }
569
570 /**
571 * Gets the role of this object.
572 *
573 * @return an instance of {@code AccessibleRole}
574 * describing the role of the object
575 * @see AccessibleRole
576 */
577 public AccessibleRole getAccessibleRole() {
578 return AccessibleRole.AWT_COMPONENT; // Non-specific -- overridden in subclasses
579 }
580
581 /**
582 * Gets the state of this object.
583 *
584 * @return an instance of {@code AccessibleStateSet}
585 * containing the current state set of the object
586 * @see AccessibleState
587 */
588 public AccessibleStateSet getAccessibleStateSet() {
589 return MenuComponent.this.getAccessibleStateSet();
590 }
591
592 /**
593 * Gets the {@code Accessible} parent of this object.
594 * If the parent of this object implements {@code Accessible},
595 * this method should simply return {@code getParent}.
596 *
597 * @return the {@code Accessible} parent of this object -- can
598 * be {@code null} if this object does not have an
599 * {@code Accessible} parent
600 */
601 public Accessible getAccessibleParent() {
602 if (accessibleParent != null) {
603 return accessibleParent;
604 } else {
605 MenuContainer parent = MenuComponent.this.getParent();
606 if (parent instanceof Accessible) {
607 return (Accessible) parent;
608 }
609 }
610 return null;
611 }
612
613 /**
614 * Gets the index of this object in its accessible parent.
615 *
616 * @return the index of this object in its parent; -1 if this
617 * object does not have an accessible parent
618 * @see #getAccessibleParent
619 */
620 public int getAccessibleIndexInParent() {
621 return MenuComponent.this.getAccessibleIndexInParent();
622 }
623
624 /**
625 * Returns the number of accessible children in the object. If all
626 * of the children of this object implement {@code Accessible},
627 * then this method should return the number of children of this object.
628 *
629 * @return the number of accessible children in the object
630 */
631 public int getAccessibleChildrenCount() {
632 return 0; // MenuComponents don't have children
633 }
634
635 /**
636 * Returns the nth {@code Accessible} child of the object.
637 *
638 * @param i zero-based index of child
639 * @return the nth Accessible child of the object
640 */
641 public Accessible getAccessibleChild(int i) {
642 return null; // MenuComponents don't have children
643 }
644
645 /**
646 * Returns the locale of this object.
647 *
648 * @return the locale of this object
649 */
650 public java.util.Locale getLocale() {
651 MenuContainer parent = MenuComponent.this.getParent();
652 if (parent instanceof Component)
653 return ((Component)parent).getLocale();
654 else
655 return java.util.Locale.getDefault();
656 }
657
658 /**
659 * Gets the {@code AccessibleComponent} associated with
660 * this object if one exists. Otherwise return {@code null}.
661 *
662 * @return the component
663 */
664 public AccessibleComponent getAccessibleComponent() {
665 return this;
666 }
667
668
669 // AccessibleComponent methods
670 //
671 /**
672 * Gets the background color of this object.
673 *
674 * @return the background color, if supported, of the object;
675 * otherwise, {@code null}
676 */
677 public Color getBackground() {
678 return null; // Not supported for MenuComponents
679 }
680
681 /**
682 * Sets the background color of this object.
683 * (For transparency, see {@code isOpaque}.)
684 *
685 * @param c the new {@code Color} for the background
686 * @see Component#isOpaque
687 */
688 public void setBackground(Color c) {
689 // Not supported for MenuComponents
690 }
691
692 /**
693 * Gets the foreground color of this object.
694 *
695 * @return the foreground color, if supported, of the object;
696 * otherwise, {@code null}
697 */
698 public Color getForeground() {
699 return null; // Not supported for MenuComponents
700 }
701
702 /**
703 * Sets the foreground color of this object.
704 *
705 * @param c the new {@code Color} for the foreground
706 */
707 public void setForeground(Color c) {
708 // Not supported for MenuComponents
709 }
710
711 /**
712 * Gets the {@code Cursor} of this object.
713 *
714 * @return the {@code Cursor}, if supported, of the object;
715 * otherwise, {@code null}
716 */
717 public Cursor getCursor() {
718 return null; // Not supported for MenuComponents
719 }
720
721 /**
722 * Sets the {@code Cursor} of this object.
723 * <p>
724 * The method may have no visual effect if the Java platform
725 * implementation and/or the native system do not support
726 * changing the mouse cursor shape.
727 * @param cursor the new {@code Cursor} for the object
728 */
729 public void setCursor(Cursor cursor) {
730 // Not supported for MenuComponents
731 }
732
733 /**
734 * Gets the {@code Font} of this object.
735 *
736 * @return the {@code Font},if supported, for the object;
737 * otherwise, {@code null}
738 */
739 public Font getFont() {
740 return MenuComponent.this.getFont();
741 }
742
743 /**
744 * Sets the {@code Font} of this object.
745 *
746 * @param f the new {@code Font} for the object
747 */
748 public void setFont(Font f) {
749 MenuComponent.this.setFont(f);
750 }
751
752 /**
753 * Gets the {@code FontMetrics} of this object.
754 *
755 * @param f the {@code Font}
756 * @return the FontMetrics, if supported, the object;
757 * otherwise, {@code null}
758 * @see #getFont
759 */
760 public FontMetrics getFontMetrics(Font f) {
761 return null; // Not supported for MenuComponents
762 }
763
764 /**
765 * Determines if the object is enabled.
766 *
767 * @return true if object is enabled; otherwise, false
768 */
769 public boolean isEnabled() {
770 return true; // Not supported for MenuComponents
771 }
772
773 /**
774 * Sets the enabled state of the object.
775 *
776 * @param b if true, enables this object; otherwise, disables it
777 */
778 public void setEnabled(boolean b) {
779 // Not supported for MenuComponents
780 }
781
782 /**
783 * Determines if the object is visible. Note: this means that the
784 * object intends to be visible; however, it may not in fact be
785 * showing on the screen because one of the objects that this object
786 * is contained by is not visible. To determine if an object is
787 * showing on the screen, use {@code isShowing}.
788 *
789 * @return true if object is visible; otherwise, false
790 */
791 public boolean isVisible() {
792 return true; // Not supported for MenuComponents
793 }
794
795 /**
796 * Sets the visible state of the object.
797 *
798 * @param b if true, shows this object; otherwise, hides it
799 */
800 public void setVisible(boolean b) {
801 // Not supported for MenuComponents
802 }
803
804 /**
805 * Determines if the object is showing. This is determined by checking
806 * the visibility of the object and ancestors of the object. Note:
807 * this will return true even if the object is obscured by another
808 * (for example, it happens to be underneath a menu that was pulled
809 * down).
810 *
811 * @return true if object is showing; otherwise, false
812 */
813 public boolean isShowing() {
814 return true; // Not supported for MenuComponents
815 }
816
817 /**
818 * Checks whether the specified point is within this object's bounds,
819 * where the point's x and y coordinates are defined to be relative to
820 * the coordinate system of the object.
821 *
822 * @param p the {@code Point} relative to the coordinate
823 * system of the object
824 * @return true if object contains {@code Point}; otherwise false
825 */
826 public boolean contains(Point p) {
827 return false; // Not supported for MenuComponents
828 }
829
830 /**
831 * Returns the location of the object on the screen.
832 *
833 * @return location of object on screen -- can be {@code null}
834 * if this object is not on the screen
835 */
836 public Point getLocationOnScreen() {
837 return null; // Not supported for MenuComponents
838 }
839
840 /**
841 * Gets the location of the object relative to the parent in the form
842 * of a point specifying the object's top-left corner in the screen's
843 * coordinate space.
844 *
845 * @return an instance of {@code Point} representing the
846 * top-left corner of the object's bounds in the coordinate
847 * space of the screen; {@code null} if
848 * this object or its parent are not on the screen
849 */
850 public Point getLocation() {
851 return null; // Not supported for MenuComponents
852 }
853
854 /**
855 * Sets the location of the object relative to the parent.
856 */
857 public void setLocation(Point p) {
858 // Not supported for MenuComponents
859 }
860
861 /**
862 * Gets the bounds of this object in the form of a
863 * {@code Rectangle} object.
864 * The bounds specify this object's width, height, and location
865 * relative to its parent.
866 *
867 * @return a rectangle indicating this component's bounds;
868 * {@code null} if this object is not on the screen
869 */
870 public Rectangle getBounds() {
871 return null; // Not supported for MenuComponents
872 }
873
874 /**
875 * Sets the bounds of this object in the form of a
876 * {@code Rectangle} object.
877 * The bounds specify this object's width, height, and location
878 * relative to its parent.
879 *
880 * @param r a rectangle indicating this component's bounds
881 */
882 public void setBounds(Rectangle r) {
883 // Not supported for MenuComponents
884 }
885
886 /**
887 * Returns the size of this object in the form of a
888 * {@code Dimension} object. The height field of
889 * the {@code Dimension} object contains this object's
890 * height, and the width field of the {@code Dimension}
891 * object contains this object's width.
892 *
893 * @return a {@code Dimension} object that indicates the
894 * size of this component; {@code null}
895 * if this object is not on the screen
896 */
897 public Dimension getSize() {
898 return null; // Not supported for MenuComponents
899 }
900
901 /**
902 * Resizes this object.
903 *
904 * @param d the {@code Dimension} specifying the
905 * new size of the object
906 */
907 public void setSize(Dimension d) {
908 // Not supported for MenuComponents
909 }
910
911 /**
912 * Returns the {@code Accessible} child, if one exists,
913 * contained at the local coordinate {@code Point}.
914 * If there is no {@code Accessible} child, {@code null}
915 * is returned.
916 *
917 * @param p the point defining the top-left corner of the
918 * {@code Accessible}, given in the coordinate space
919 * of the object's parent
920 * @return the {@code Accessible}, if it exists,
921 * at the specified location; else {@code null}
922 */
923 public Accessible getAccessibleAt(Point p) {
924 return null; // MenuComponents don't have children
925 }
926
927 /**
928 * Returns whether this object can accept focus or not.
929 *
930 * @return true if object can accept focus; otherwise false
931 */
932 public boolean isFocusTraversable() {
933 return true; // Not supported for MenuComponents
934 }
935
936 /**
937 * Requests focus for this object.
938 */
939 public void requestFocus() {
940 // Not supported for MenuComponents
941 }
942
943 /**
944 * Adds the specified focus listener to receive focus events from this
945 * component.
946 *
947 * @param l the focus listener
948 */
949 public void addFocusListener(java.awt.event.FocusListener l) {
950 // Not supported for MenuComponents
951 }
952
953 /**
954 * Removes the specified focus listener so it no longer receives focus
955 * events from this component.
956 *
957 * @param l the focus listener
958 */
959 public void removeFocusListener(java.awt.event.FocusListener l) {
960 // Not supported for MenuComponents
961 }
962
963 // AccessibleSelection methods
964 //
965
966 /**
967 * Returns the number of {@code Accessible} children currently selected.
968 * If no children are selected, the return value will be 0.
969 *
970 * @return the number of items currently selected
971 */
972 public int getAccessibleSelectionCount() {
973 return 0; // To be fully implemented in a future release
974 }
975
976 /**
977 * Returns an {@code Accessible} representing the specified
978 * selected child in the object. If there isn't a selection, or there are
979 * fewer children selected than the integer passed in, the return
980 * value will be {@code null}.
981 * <p>Note that the index represents the i-th selected child, which
982 * is different from the i-th child.
983 *
984 * @param i the zero-based index of selected children
985 * @return the i-th selected child
986 * @see #getAccessibleSelectionCount
987 */
988 public Accessible getAccessibleSelection(int i) {
989 return null; // To be fully implemented in a future release
990 }
991
992 /**
993 * Determines if the current child of this object is selected.
994 *
995 * @return true if the current child of this object is selected;
996 * else false
997 * @param i the zero-based index of the child in this
998 * {@code Accessible} object
999 * @see AccessibleContext#getAccessibleChild
1000 */
1001 public boolean isAccessibleChildSelected(int i) {
1002 return false; // To be fully implemented in a future release
1003 }
1004
1005 /**
1006 * Adds the specified {@code Accessible} child of the object
1007 * to the object's selection. If the object supports multiple selections,
1008 * the specified child is added to any existing selection, otherwise
1009 * it replaces any existing selection in the object. If the
1010 * specified child is already selected, this method has no effect.
1011 *
1012 * @param i the zero-based index of the child
1013 * @see AccessibleContext#getAccessibleChild
1014 */
1015 public void addAccessibleSelection(int i) {
1016 // To be fully implemented in a future release
1017 }
1018
1019 /**
1020 * Removes the specified child of the object from the object's
1021 * selection. If the specified item isn't currently selected, this
1022 * method has no effect.
1023 *
1024 * @param i the zero-based index of the child
1025 * @see AccessibleContext#getAccessibleChild
1026 */
1027 public void removeAccessibleSelection(int i) {
1028 // To be fully implemented in a future release
1029 }
1030
1031 /**
1032 * Clears the selection in the object, so that no children in the
1033 * object are selected.
1034 */
1035 public void clearAccessibleSelection() {
1036 // To be fully implemented in a future release
1037 }
1038
1039 /**
1040 * Causes every child of the object to be selected
1041 * if the object supports multiple selections.
1042 */
1043 public void selectAllAccessibleSelection() {
1044 // To be fully implemented in a future release
1045 }
1046
1047 } // inner class AccessibleAWTComponent
1048
1049 /**
1050 * Gets the index of this object in its accessible parent.
1051 *
1052 * @return -1 if this object does not have an accessible parent;
1053 * otherwise, the index of the child in its accessible parent.
1054 */
1055 int getAccessibleIndexInParent() {
1056 MenuContainer localParent = parent;
1057 if (!(localParent instanceof MenuComponent)) {
1058 // MenuComponents only have accessible index when inside MenuComponents
1059 return -1;
1060 }
1061 MenuComponent localParentMenu = (MenuComponent)localParent;
1062 return localParentMenu.getAccessibleChildIndex(this);
1063 }
1064
1065 /**
1066 * Gets the index of the child within this MenuComponent.
1067 *
1068 * @param child MenuComponent whose index we are interested in.
1069 * @return -1 if this object doesn't contain the child,
1070 * otherwise, index of the child.
1071 */
1072 int getAccessibleChildIndex(MenuComponent child) {
1073 return -1; // Overridden in subclasses.
1074 }
1075
1076 /**
1077 * Gets the state of this object.
1078 *
1079 * @return an instance of {@code AccessibleStateSet}
1080 * containing the current state set of the object
1081 * @see AccessibleState
1082 */
1083 AccessibleStateSet getAccessibleStateSet() {
1084 AccessibleStateSet states = new AccessibleStateSet();
1085 return states;
1086 }
1087
1088 }