1 /*
2 * Copyright (c) 1996, 2014, 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 package java.awt;
26
27 import java.awt.event.*;
28 import java.lang.reflect.Array;
29 import java.util.EventListener;
30 import java.io.Serializable;
31 import java.io.ObjectOutputStream;
32 import java.io.IOException;
33 import java.util.EventListener;
34
35
36 /**
37 * {@code AWTEventMulticaster} implements efficient and thread-safe multi-cast
38 * event dispatching for the AWT events defined in the {@code java.awt.event}
39 * package.
40 * <p>
41 * The following example illustrates how to use this class:
42 *
43 * <pre><code>
44 * public myComponent extends Component {
45 * ActionListener actionListener = null;
46 *
47 * public synchronized void addActionListener(ActionListener l) {
48 * actionListener = AWTEventMulticaster.add(actionListener, l);
49 * }
50 * public synchronized void removeActionListener(ActionListener l) {
51 * actionListener = AWTEventMulticaster.remove(actionListener, l);
52 * }
53 * public void processEvent(AWTEvent e) {
54 * // when event occurs which causes "action" semantic
55 * ActionListener listener = actionListener;
56 * if (listener != null) {
57 * listener.actionPerformed(new ActionEvent());
58 * }
59 * }
60 * }
61 * </code></pre>
62 * The important point to note is the first argument to the {@code
63 * add} and {@code remove} methods is the field maintaining the
64 * listeners. In addition you must assign the result of the {@code add}
65 * and {@code remove} methods to the field maintaining the listeners.
66 * <p>
67 * {@code AWTEventMulticaster} is implemented as a pair of {@code
68 * EventListeners} that are set at construction time. {@code
69 * AWTEventMulticaster} is immutable. The {@code add} and {@code
70 * remove} methods do not alter {@code AWTEventMulticaster} in
71 * anyway. If necessary, a new {@code AWTEventMulticaster} is
72 * created. In this way it is safe to add and remove listeners during
73 * the process of an event dispatching. However, event listeners
74 * added during the process of an event dispatch operation are not
75 * notified of the event currently being dispatched.
76 * <p>
77 * All of the {@code add} methods allow {@code null} arguments. If the
78 * first argument is {@code null}, the second argument is returned. If
79 * the first argument is not {@code null} and the second argument is
80 * {@code null}, the first argument is returned. If both arguments are
81 * {@code non-null}, a new {@code AWTEventMulticaster} is created using
82 * the two arguments and returned.
83 * <p>
84 * For the {@code remove} methods that take two arguments, the following is
85 * returned:
86 * <ul>
87 * <li>{@code null}, if the first argument is {@code null}, or
88 * the arguments are equal, by way of {@code ==}.
89 * <li>the first argument, if the first argument is not an instance of
90 * {@code AWTEventMulticaster}.
91 * <li>result of invoking {@code remove(EventListener)} on the
92 * first argument, supplying the second argument to the
93 * {@code remove(EventListener)} method.
94 * </ul>
95 * <p>Swing makes use of
96 * {@link javax.swing.event.EventListenerList EventListenerList} for
97 * similar logic. Refer to it for details.
98 *
99 * @see javax.swing.event.EventListenerList
100 *
101 * @author John Rose
102 * @author Amy Fowler
103 * @since 1.1
104 */
105
106 public class AWTEventMulticaster implements
107 ComponentListener, ContainerListener, FocusListener, KeyListener,
108 MouseListener, MouseMotionListener, WindowListener, WindowFocusListener,
109 WindowStateListener, ActionListener, ItemListener, AdjustmentListener,
110 TextListener, InputMethodListener, HierarchyListener,
111 HierarchyBoundsListener, MouseWheelListener {
112
113 /**
114 * A variable in the event chain (listener-a)
115 */
116 protected final EventListener a;
117
118 /**
119 * A variable in the event chain (listener-b)
120 */
121 protected final EventListener b;
122
123 /**
124 * Creates an event multicaster instance which chains listener-a
125 * with listener-b. Input parameters <code>a</code> and <code>b</code>
126 * should not be <code>null</code>, though implementations may vary in
127 * choosing whether or not to throw <code>NullPointerException</code>
128 * in that case.
129 * @param a listener-a
130 * @param b listener-b
131 */
132 protected AWTEventMulticaster(EventListener a, EventListener b) {
133 this.a = a; this.b = b;
134 }
135
136 /**
137 * Removes a listener from this multicaster.
138 * <p>
139 * The returned multicaster contains all the listeners in this
140 * multicaster with the exception of all occurrences of {@code oldl}.
141 * If the resulting multicaster contains only one regular listener
142 * the regular listener may be returned. If the resulting multicaster
143 * is empty, then {@code null} may be returned instead.
144 * <p>
145 * No exception is thrown if {@code oldl} is {@code null}.
146 *
147 * @param oldl the listener to be removed
148 * @return resulting listener
149 */
150 protected EventListener remove(EventListener oldl) {
151 if (oldl == a) return b;
152 if (oldl == b) return a;
153 EventListener a2 = removeInternal(a, oldl);
154 EventListener b2 = removeInternal(b, oldl);
155 if (a2 == a && b2 == b) {
156 return this; // it's not here
157 }
158 return addInternal(a2, b2);
159 }
160
161 /**
162 * Handles the componentResized event by invoking the
163 * componentResized methods on listener-a and listener-b.
164 * @param e the component event
165 */
166 public void componentResized(ComponentEvent e) {
167 ((ComponentListener)a).componentResized(e);
168 ((ComponentListener)b).componentResized(e);
169 }
170
171 /**
172 * Handles the componentMoved event by invoking the
173 * componentMoved methods on listener-a and listener-b.
174 * @param e the component event
175 */
176 public void componentMoved(ComponentEvent e) {
177 ((ComponentListener)a).componentMoved(e);
178 ((ComponentListener)b).componentMoved(e);
179 }
180
181 /**
182 * Handles the componentShown event by invoking the
183 * componentShown methods on listener-a and listener-b.
184 * @param e the component event
185 */
186 public void componentShown(ComponentEvent e) {
187 ((ComponentListener)a).componentShown(e);
188 ((ComponentListener)b).componentShown(e);
189 }
190
191 /**
192 * Handles the componentHidden event by invoking the
193 * componentHidden methods on listener-a and listener-b.
194 * @param e the component event
195 */
196 public void componentHidden(ComponentEvent e) {
197 ((ComponentListener)a).componentHidden(e);
198 ((ComponentListener)b).componentHidden(e);
199 }
200
201 /**
202 * Handles the componentAdded container event by invoking the
203 * componentAdded methods on listener-a and listener-b.
204 * @param e the component event
205 */
206 public void componentAdded(ContainerEvent e) {
207 ((ContainerListener)a).componentAdded(e);
208 ((ContainerListener)b).componentAdded(e);
209 }
210
211 /**
212 * Handles the componentRemoved container event by invoking the
213 * componentRemoved methods on listener-a and listener-b.
214 * @param e the component event
215 */
216 public void componentRemoved(ContainerEvent e) {
217 ((ContainerListener)a).componentRemoved(e);
218 ((ContainerListener)b).componentRemoved(e);
219 }
220
221 /**
222 * Handles the focusGained event by invoking the
223 * focusGained methods on listener-a and listener-b.
224 * @param e the focus event
225 */
226 public void focusGained(FocusEvent e) {
227 ((FocusListener)a).focusGained(e);
228 ((FocusListener)b).focusGained(e);
229 }
230
231 /**
232 * Handles the focusLost event by invoking the
233 * focusLost methods on listener-a and listener-b.
234 * @param e the focus event
235 */
236 public void focusLost(FocusEvent e) {
237 ((FocusListener)a).focusLost(e);
238 ((FocusListener)b).focusLost(e);
239 }
240
241 /**
242 * Handles the keyTyped event by invoking the
243 * keyTyped methods on listener-a and listener-b.
244 * @param e the key event
245 */
246 public void keyTyped(KeyEvent e) {
247 ((KeyListener)a).keyTyped(e);
248 ((KeyListener)b).keyTyped(e);
249 }
250
251 /**
252 * Handles the keyPressed event by invoking the
253 * keyPressed methods on listener-a and listener-b.
254 * @param e the key event
255 */
256 public void keyPressed(KeyEvent e) {
257 ((KeyListener)a).keyPressed(e);
258 ((KeyListener)b).keyPressed(e);
259 }
260
261 /**
262 * Handles the keyReleased event by invoking the
263 * keyReleased methods on listener-a and listener-b.
264 * @param e the key event
265 */
266 public void keyReleased(KeyEvent e) {
267 ((KeyListener)a).keyReleased(e);
268 ((KeyListener)b).keyReleased(e);
269 }
270
271 /**
272 * Handles the mouseClicked event by invoking the
273 * mouseClicked methods on listener-a and listener-b.
274 * @param e the mouse event
275 */
276 public void mouseClicked(MouseEvent e) {
277 ((MouseListener)a).mouseClicked(e);
278 ((MouseListener)b).mouseClicked(e);
279 }
280
281 /**
282 * Handles the mousePressed event by invoking the
283 * mousePressed methods on listener-a and listener-b.
284 * @param e the mouse event
285 */
286 public void mousePressed(MouseEvent e) {
287 ((MouseListener)a).mousePressed(e);
288 ((MouseListener)b).mousePressed(e);
289 }
290
291 /**
292 * Handles the mouseReleased event by invoking the
293 * mouseReleased methods on listener-a and listener-b.
294 * @param e the mouse event
295 */
296 public void mouseReleased(MouseEvent e) {
297 ((MouseListener)a).mouseReleased(e);
298 ((MouseListener)b).mouseReleased(e);
299 }
300
301 /**
302 * Handles the mouseEntered event by invoking the
303 * mouseEntered methods on listener-a and listener-b.
304 * @param e the mouse event
305 */
306 public void mouseEntered(MouseEvent e) {
307 ((MouseListener)a).mouseEntered(e);
308 ((MouseListener)b).mouseEntered(e);
309 }
310
311 /**
312 * Handles the mouseExited event by invoking the
313 * mouseExited methods on listener-a and listener-b.
314 * @param e the mouse event
315 */
316 public void mouseExited(MouseEvent e) {
317 ((MouseListener)a).mouseExited(e);
318 ((MouseListener)b).mouseExited(e);
319 }
320
321 /**
322 * Handles the mouseDragged event by invoking the
323 * mouseDragged methods on listener-a and listener-b.
324 * @param e the mouse event
325 */
326 public void mouseDragged(MouseEvent e) {
327 ((MouseMotionListener)a).mouseDragged(e);
328 ((MouseMotionListener)b).mouseDragged(e);
329 }
330
331 /**
332 * Handles the mouseMoved event by invoking the
333 * mouseMoved methods on listener-a and listener-b.
334 * @param e the mouse event
335 */
336 public void mouseMoved(MouseEvent e) {
337 ((MouseMotionListener)a).mouseMoved(e);
338 ((MouseMotionListener)b).mouseMoved(e);
339 }
340
341 /**
342 * Handles the windowOpened event by invoking the
343 * windowOpened methods on listener-a and listener-b.
344 * @param e the window event
345 */
346 public void windowOpened(WindowEvent e) {
347 ((WindowListener)a).windowOpened(e);
348 ((WindowListener)b).windowOpened(e);
349 }
350
351 /**
352 * Handles the windowClosing event by invoking the
353 * windowClosing methods on listener-a and listener-b.
354 * @param e the window event
355 */
356 public void windowClosing(WindowEvent e) {
357 ((WindowListener)a).windowClosing(e);
358 ((WindowListener)b).windowClosing(e);
359 }
360
361 /**
362 * Handles the windowClosed event by invoking the
363 * windowClosed methods on listener-a and listener-b.
364 * @param e the window event
365 */
366 public void windowClosed(WindowEvent e) {
367 ((WindowListener)a).windowClosed(e);
368 ((WindowListener)b).windowClosed(e);
369 }
370
371 /**
372 * Handles the windowIconified event by invoking the
373 * windowIconified methods on listener-a and listener-b.
374 * @param e the window event
375 */
376 public void windowIconified(WindowEvent e) {
377 ((WindowListener)a).windowIconified(e);
378 ((WindowListener)b).windowIconified(e);
379 }
380
381 /**
382 * Handles the windowDeiconified event by invoking the
383 * windowDeiconified methods on listener-a and listener-b.
384 * @param e the window event
385 */
386 public void windowDeiconified(WindowEvent e) {
387 ((WindowListener)a).windowDeiconified(e);
388 ((WindowListener)b).windowDeiconified(e);
389 }
390
391 /**
392 * Handles the windowActivated event by invoking the
393 * windowActivated methods on listener-a and listener-b.
394 * @param e the window event
395 */
396 public void windowActivated(WindowEvent e) {
397 ((WindowListener)a).windowActivated(e);
398 ((WindowListener)b).windowActivated(e);
399 }
400
401 /**
402 * Handles the windowDeactivated event by invoking the
403 * windowDeactivated methods on listener-a and listener-b.
404 * @param e the window event
405 */
406 public void windowDeactivated(WindowEvent e) {
407 ((WindowListener)a).windowDeactivated(e);
408 ((WindowListener)b).windowDeactivated(e);
409 }
410
411 /**
412 * Handles the windowStateChanged event by invoking the
413 * windowStateChanged methods on listener-a and listener-b.
414 * @param e the window event
415 * @since 1.4
416 */
417 public void windowStateChanged(WindowEvent e) {
418 ((WindowStateListener)a).windowStateChanged(e);
419 ((WindowStateListener)b).windowStateChanged(e);
420 }
421
422
423 /**
424 * Handles the windowGainedFocus event by invoking the windowGainedFocus
425 * methods on listener-a and listener-b.
426 * @param e the window event
427 * @since 1.4
428 */
429 public void windowGainedFocus(WindowEvent e) {
430 ((WindowFocusListener)a).windowGainedFocus(e);
431 ((WindowFocusListener)b).windowGainedFocus(e);
432 }
433
434 /**
435 * Handles the windowLostFocus event by invoking the windowLostFocus
436 * methods on listener-a and listener-b.
437 * @param e the window event
438 * @since 1.4
439 */
440 public void windowLostFocus(WindowEvent e) {
441 ((WindowFocusListener)a).windowLostFocus(e);
442 ((WindowFocusListener)b).windowLostFocus(e);
443 }
444
445 /**
446 * Handles the actionPerformed event by invoking the
447 * actionPerformed methods on listener-a and listener-b.
448 * @param e the action event
449 */
450 public void actionPerformed(ActionEvent e) {
451 ((ActionListener)a).actionPerformed(e);
452 ((ActionListener)b).actionPerformed(e);
453 }
454
455 /**
456 * Handles the itemStateChanged event by invoking the
457 * itemStateChanged methods on listener-a and listener-b.
458 * @param e the item event
459 */
460 public void itemStateChanged(ItemEvent e) {
461 ((ItemListener)a).itemStateChanged(e);
462 ((ItemListener)b).itemStateChanged(e);
463 }
464
465 /**
466 * Handles the adjustmentValueChanged event by invoking the
467 * adjustmentValueChanged methods on listener-a and listener-b.
468 * @param e the adjustment event
469 */
470 public void adjustmentValueChanged(AdjustmentEvent e) {
471 ((AdjustmentListener)a).adjustmentValueChanged(e);
472 ((AdjustmentListener)b).adjustmentValueChanged(e);
473 }
474 public void textValueChanged(TextEvent e) {
475 ((TextListener)a).textValueChanged(e);
476 ((TextListener)b).textValueChanged(e);
477 }
478
479 /**
480 * Handles the inputMethodTextChanged event by invoking the
481 * inputMethodTextChanged methods on listener-a and listener-b.
482 * @param e the item event
483 */
484 public void inputMethodTextChanged(InputMethodEvent e) {
485 ((InputMethodListener)a).inputMethodTextChanged(e);
486 ((InputMethodListener)b).inputMethodTextChanged(e);
487 }
488
489 /**
490 * Handles the caretPositionChanged event by invoking the
491 * caretPositionChanged methods on listener-a and listener-b.
492 * @param e the item event
493 */
494 public void caretPositionChanged(InputMethodEvent e) {
495 ((InputMethodListener)a).caretPositionChanged(e);
496 ((InputMethodListener)b).caretPositionChanged(e);
497 }
498
499 /**
500 * Handles the hierarchyChanged event by invoking the
501 * hierarchyChanged methods on listener-a and listener-b.
502 * @param e the item event
503 * @since 1.3
504 */
505 public void hierarchyChanged(HierarchyEvent e) {
506 ((HierarchyListener)a).hierarchyChanged(e);
507 ((HierarchyListener)b).hierarchyChanged(e);
508 }
509
510 /**
511 * Handles the ancestorMoved event by invoking the
512 * ancestorMoved methods on listener-a and listener-b.
513 * @param e the item event
514 * @since 1.3
515 */
516 public void ancestorMoved(HierarchyEvent e) {
517 ((HierarchyBoundsListener)a).ancestorMoved(e);
518 ((HierarchyBoundsListener)b).ancestorMoved(e);
519 }
520
521 /**
522 * Handles the ancestorResized event by invoking the
523 * ancestorResized methods on listener-a and listener-b.
524 * @param e the item event
525 * @since 1.3
526 */
527 public void ancestorResized(HierarchyEvent e) {
528 ((HierarchyBoundsListener)a).ancestorResized(e);
529 ((HierarchyBoundsListener)b).ancestorResized(e);
530 }
531
532 /**
533 * Handles the mouseWheelMoved event by invoking the
534 * mouseWheelMoved methods on listener-a and listener-b.
535 * @param e the mouse event
536 * @since 1.4
537 */
538 public void mouseWheelMoved(MouseWheelEvent e) {
539 ((MouseWheelListener)a).mouseWheelMoved(e);
540 ((MouseWheelListener)b).mouseWheelMoved(e);
541 }
542
543 /**
544 * Adds component-listener-a with component-listener-b and
545 * returns the resulting multicast listener.
546 * @param a component-listener-a
547 * @param b component-listener-b
548 * @return the resulting listener
549 */
550 public static ComponentListener add(ComponentListener a, ComponentListener b) {
551 return (ComponentListener)addInternal(a, b);
552 }
553
554 /**
555 * Adds container-listener-a with container-listener-b and
556 * returns the resulting multicast listener.
557 * @param a container-listener-a
558 * @param b container-listener-b
559 * @return the resulting listener
560 */
561 public static ContainerListener add(ContainerListener a, ContainerListener b) {
562 return (ContainerListener)addInternal(a, b);
563 }
564
565 /**
566 * Adds focus-listener-a with focus-listener-b and
567 * returns the resulting multicast listener.
568 * @param a focus-listener-a
569 * @param b focus-listener-b
570 * @return the resulting listener
571 */
572 public static FocusListener add(FocusListener a, FocusListener b) {
573 return (FocusListener)addInternal(a, b);
574 }
575
576 /**
577 * Adds key-listener-a with key-listener-b and
578 * returns the resulting multicast listener.
579 * @param a key-listener-a
580 * @param b key-listener-b
581 * @return the resulting listener
582 */
583 public static KeyListener add(KeyListener a, KeyListener b) {
584 return (KeyListener)addInternal(a, b);
585 }
586
587 /**
588 * Adds mouse-listener-a with mouse-listener-b and
589 * returns the resulting multicast listener.
590 * @param a mouse-listener-a
591 * @param b mouse-listener-b
592 * @return the resulting listener
593 */
594 public static MouseListener add(MouseListener a, MouseListener b) {
595 return (MouseListener)addInternal(a, b);
596 }
597
598 /**
599 * Adds mouse-motion-listener-a with mouse-motion-listener-b and
600 * returns the resulting multicast listener.
601 * @param a mouse-motion-listener-a
602 * @param b mouse-motion-listener-b
603 * @return the resulting listener
604 */
605 public static MouseMotionListener add(MouseMotionListener a, MouseMotionListener b) {
606 return (MouseMotionListener)addInternal(a, b);
607 }
608
609 /**
610 * Adds window-listener-a with window-listener-b and
611 * returns the resulting multicast listener.
612 * @param a window-listener-a
613 * @param b window-listener-b
614 * @return the resulting listener
615 */
616 public static WindowListener add(WindowListener a, WindowListener b) {
617 return (WindowListener)addInternal(a, b);
618 }
619
620 /**
621 * Adds window-state-listener-a with window-state-listener-b
622 * and returns the resulting multicast listener.
623 * @param a window-state-listener-a
624 * @param b window-state-listener-b
625 * @return the resulting listener
626 * @since 1.4
627 */
628 @SuppressWarnings("overloads")
629 public static WindowStateListener add(WindowStateListener a,
630 WindowStateListener b) {
631 return (WindowStateListener)addInternal(a, b);
632 }
633
634 /**
635 * Adds window-focus-listener-a with window-focus-listener-b
636 * and returns the resulting multicast listener.
637 * @param a window-focus-listener-a
638 * @param b window-focus-listener-b
639 * @return the resulting listener
640 * @since 1.4
641 */
642 public static WindowFocusListener add(WindowFocusListener a,
643 WindowFocusListener b) {
644 return (WindowFocusListener)addInternal(a, b);
645 }
646
647 /**
648 * Adds action-listener-a with action-listener-b and
649 * returns the resulting multicast listener.
650 * @param a action-listener-a
651 * @param b action-listener-b
652 * @return the resulting listener
653 */
654 @SuppressWarnings("overloads")
655 public static ActionListener add(ActionListener a, ActionListener b) {
656 return (ActionListener)addInternal(a, b);
657 }
658
659 /**
660 * Adds item-listener-a with item-listener-b and
661 * returns the resulting multicast listener.
662 * @param a item-listener-a
663 * @param b item-listener-b
664 * @return the resulting listener
665 */
666 @SuppressWarnings("overloads")
667 public static ItemListener add(ItemListener a, ItemListener b) {
668 return (ItemListener)addInternal(a, b);
669 }
670
671 /**
672 * Adds adjustment-listener-a with adjustment-listener-b and
673 * returns the resulting multicast listener.
674 * @param a adjustment-listener-a
675 * @param b adjustment-listener-b
676 * @return the resulting listener
677 */
678 @SuppressWarnings("overloads")
679 public static AdjustmentListener add(AdjustmentListener a, AdjustmentListener b) {
680 return (AdjustmentListener)addInternal(a, b);
681 }
682
683 /**
684 * Adds text-listener-a with text-listener-b and
685 * returns the resulting multicast listener.
686 *
687 * @param a text-listener-a
688 * @param b text-listener-b
689 * @return the resulting listener
690 */
691 @SuppressWarnings("overloads")
692 public static TextListener add(TextListener a, TextListener b) {
693 return (TextListener)addInternal(a, b);
694 }
695
696 /**
697 * Adds input-method-listener-a with input-method-listener-b and
698 * returns the resulting multicast listener.
699 * @param a input-method-listener-a
700 * @param b input-method-listener-b
701 * @return the resulting listener
702 */
703 public static InputMethodListener add(InputMethodListener a, InputMethodListener b) {
704 return (InputMethodListener)addInternal(a, b);
705 }
706
707 /**
708 * Adds hierarchy-listener-a with hierarchy-listener-b and
709 * returns the resulting multicast listener.
710 * @param a hierarchy-listener-a
711 * @param b hierarchy-listener-b
712 * @return the resulting listener
713 * @since 1.3
714 */
715 @SuppressWarnings("overloads")
716 public static HierarchyListener add(HierarchyListener a, HierarchyListener b) {
717 return (HierarchyListener)addInternal(a, b);
718 }
719
720 /**
721 * Adds hierarchy-bounds-listener-a with hierarchy-bounds-listener-b and
722 * returns the resulting multicast listener.
723 * @param a hierarchy-bounds-listener-a
724 * @param b hierarchy-bounds-listener-b
725 * @return the resulting listener
726 * @since 1.3
727 */
728 public static HierarchyBoundsListener add(HierarchyBoundsListener a, HierarchyBoundsListener b) {
729 return (HierarchyBoundsListener)addInternal(a, b);
730 }
731
732 /**
733 * Adds mouse-wheel-listener-a with mouse-wheel-listener-b and
734 * returns the resulting multicast listener.
735 * @param a mouse-wheel-listener-a
736 * @param b mouse-wheel-listener-b
737 * @return the resulting listener
738 * @since 1.4
739 */
740 @SuppressWarnings("overloads")
741 public static MouseWheelListener add(MouseWheelListener a,
742 MouseWheelListener b) {
743 return (MouseWheelListener)addInternal(a, b);
744 }
745
746 /**
747 * Removes the old component-listener from component-listener-l and
748 * returns the resulting multicast listener.
749 * @param l component-listener-l
750 * @param oldl the component-listener being removed
751 * @return the resulting listener
752 */
753 public static ComponentListener remove(ComponentListener l, ComponentListener oldl) {
754 return (ComponentListener) removeInternal(l, oldl);
755 }
756
757 /**
758 * Removes the old container-listener from container-listener-l and
759 * returns the resulting multicast listener.
760 * @param l container-listener-l
761 * @param oldl the container-listener being removed
762 * @return the resulting listener
763 */
764 public static ContainerListener remove(ContainerListener l, ContainerListener oldl) {
765 return (ContainerListener) removeInternal(l, oldl);
766 }
767
768 /**
769 * Removes the old focus-listener from focus-listener-l and
770 * returns the resulting multicast listener.
771 * @param l focus-listener-l
772 * @param oldl the focus-listener being removed
773 * @return the resulting listener
774 */
775 public static FocusListener remove(FocusListener l, FocusListener oldl) {
776 return (FocusListener) removeInternal(l, oldl);
777 }
778
779 /**
780 * Removes the old key-listener from key-listener-l and
781 * returns the resulting multicast listener.
782 * @param l key-listener-l
783 * @param oldl the key-listener being removed
784 * @return the resulting listener
785 */
786 public static KeyListener remove(KeyListener l, KeyListener oldl) {
787 return (KeyListener) removeInternal(l, oldl);
788 }
789
790 /**
791 * Removes the old mouse-listener from mouse-listener-l and
792 * returns the resulting multicast listener.
793 * @param l mouse-listener-l
794 * @param oldl the mouse-listener being removed
795 * @return the resulting listener
796 */
797 public static MouseListener remove(MouseListener l, MouseListener oldl) {
798 return (MouseListener) removeInternal(l, oldl);
799 }
800
801 /**
802 * Removes the old mouse-motion-listener from mouse-motion-listener-l
803 * and returns the resulting multicast listener.
804 * @param l mouse-motion-listener-l
805 * @param oldl the mouse-motion-listener being removed
806 * @return the resulting listener
807 */
808 public static MouseMotionListener remove(MouseMotionListener l, MouseMotionListener oldl) {
809 return (MouseMotionListener) removeInternal(l, oldl);
810 }
811
812 /**
813 * Removes the old window-listener from window-listener-l and
814 * returns the resulting multicast listener.
815 * @param l window-listener-l
816 * @param oldl the window-listener being removed
817 * @return the resulting listener
818 */
819 public static WindowListener remove(WindowListener l, WindowListener oldl) {
820 return (WindowListener) removeInternal(l, oldl);
821 }
822
823 /**
824 * Removes the old window-state-listener from window-state-listener-l
825 * and returns the resulting multicast listener.
826 * @param l window-state-listener-l
827 * @param oldl the window-state-listener being removed
828 * @return the resulting listener
829 * @since 1.4
830 */
831 @SuppressWarnings("overloads")
832 public static WindowStateListener remove(WindowStateListener l,
833 WindowStateListener oldl) {
834 return (WindowStateListener) removeInternal(l, oldl);
835 }
836
837 /**
838 * Removes the old window-focus-listener from window-focus-listener-l
839 * and returns the resulting multicast listener.
840 * @param l window-focus-listener-l
841 * @param oldl the window-focus-listener being removed
842 * @return the resulting listener
843 * @since 1.4
844 */
845 public static WindowFocusListener remove(WindowFocusListener l,
846 WindowFocusListener oldl) {
847 return (WindowFocusListener) removeInternal(l, oldl);
848 }
849
850 /**
851 * Removes the old action-listener from action-listener-l and
852 * returns the resulting multicast listener.
853 * @param l action-listener-l
854 * @param oldl the action-listener being removed
855 * @return the resulting listener
856 */
857 @SuppressWarnings("overloads")
858 public static ActionListener remove(ActionListener l, ActionListener oldl) {
859 return (ActionListener) removeInternal(l, oldl);
860 }
861
862 /**
863 * Removes the old item-listener from item-listener-l and
864 * returns the resulting multicast listener.
865 * @param l item-listener-l
866 * @param oldl the item-listener being removed
867 * @return the resulting listener
868 */
869 @SuppressWarnings("overloads")
870 public static ItemListener remove(ItemListener l, ItemListener oldl) {
871 return (ItemListener) removeInternal(l, oldl);
872 }
873
874 /**
875 * Removes the old adjustment-listener from adjustment-listener-l and
876 * returns the resulting multicast listener.
877 * @param l adjustment-listener-l
878 * @param oldl the adjustment-listener being removed
879 * @return the resulting listener
880 */
881 @SuppressWarnings("overloads")
882 public static AdjustmentListener remove(AdjustmentListener l, AdjustmentListener oldl) {
883 return (AdjustmentListener) removeInternal(l, oldl);
884 }
885
886 /**
887 * Removes the old text-listener from text-listener-l and
888 * returns the resulting multicast listener.
889 *
890 * @param l text-listener-l
891 * @param oldl the text-listener being removed
892 * @return the resulting listener
893 */
894 @SuppressWarnings("overloads")
895 public static TextListener remove(TextListener l, TextListener oldl) {
896 return (TextListener) removeInternal(l, oldl);
897 }
898
899 /**
900 * Removes the old input-method-listener from input-method-listener-l and
901 * returns the resulting multicast listener.
902 * @param l input-method-listener-l
903 * @param oldl the input-method-listener being removed
904 * @return the resulting listener
905 */
906 public static InputMethodListener remove(InputMethodListener l, InputMethodListener oldl) {
907 return (InputMethodListener) removeInternal(l, oldl);
908 }
909
910 /**
911 * Removes the old hierarchy-listener from hierarchy-listener-l and
912 * returns the resulting multicast listener.
913 * @param l hierarchy-listener-l
914 * @param oldl the hierarchy-listener being removed
915 * @return the resulting listener
916 * @since 1.3
917 */
918 @SuppressWarnings("overloads")
919 public static HierarchyListener remove(HierarchyListener l, HierarchyListener oldl) {
920 return (HierarchyListener) removeInternal(l, oldl);
921 }
922
923 /**
924 * Removes the old hierarchy-bounds-listener from
925 * hierarchy-bounds-listener-l and returns the resulting multicast
926 * listener.
927 * @param l hierarchy-bounds-listener-l
928 * @param oldl the hierarchy-bounds-listener being removed
929 * @return the resulting listener
930 * @since 1.3
931 */
932 public static HierarchyBoundsListener remove(HierarchyBoundsListener l, HierarchyBoundsListener oldl) {
933 return (HierarchyBoundsListener) removeInternal(l, oldl);
934 }
935
936 /**
937 * Removes the old mouse-wheel-listener from mouse-wheel-listener-l
938 * and returns the resulting multicast listener.
939 * @param l mouse-wheel-listener-l
940 * @param oldl the mouse-wheel-listener being removed
941 * @return the resulting listener
942 * @since 1.4
943 */
944 @SuppressWarnings("overloads")
945 public static MouseWheelListener remove(MouseWheelListener l,
946 MouseWheelListener oldl) {
947 return (MouseWheelListener) removeInternal(l, oldl);
948 }
949
950 /**
951 * Returns the resulting multicast listener from adding listener-a
952 * and listener-b together.
953 * If listener-a is null, it returns listener-b;
954 * If listener-b is null, it returns listener-a
955 * If neither are null, then it creates and returns
956 * a new AWTEventMulticaster instance which chains a with b.
957 * @param a event listener-a
958 * @param b event listener-b
959 * @return the resulting listener
960 */
961 protected static EventListener addInternal(EventListener a, EventListener b) {
962 if (a == null) return b;
963 if (b == null) return a;
964 return new AWTEventMulticaster(a, b);
965 }
966
967 /**
968 * Returns the resulting multicast listener after removing the
969 * old listener from listener-l.
970 * If listener-l equals the old listener OR listener-l is null,
971 * returns null.
972 * Else if listener-l is an instance of AWTEventMulticaster,
973 * then it removes the old listener from it.
974 * Else, returns listener l.
975 * @param l the listener being removed from
976 * @param oldl the listener being removed
977 * @return the resulting listener
978 */
979 protected static EventListener removeInternal(EventListener l, EventListener oldl) {
980 if (l == oldl || l == null) {
981 return null;
982 } else if (l instanceof AWTEventMulticaster) {
983 return ((AWTEventMulticaster)l).remove(oldl);
984 } else {
985 return l; // it's not here
986 }
987 }
988
989
990 /**
991 * Serialization support. Saves all Serializable listeners
992 * to a serialization stream.
993 *
994 * @param s the stream to save to
995 * @param k a prefix stream to put before each serializable listener
996 * @throws IOException if serialization fails
997 */
998 protected void saveInternal(ObjectOutputStream s, String k) throws IOException {
999 if (a instanceof AWTEventMulticaster) {
1000 ((AWTEventMulticaster)a).saveInternal(s, k);
1001 }
1002 else if (a instanceof Serializable) {
1003 s.writeObject(k);
1004 s.writeObject(a);
1005 }
1006
1007 if (b instanceof AWTEventMulticaster) {
1008 ((AWTEventMulticaster)b).saveInternal(s, k);
1009 }
1010 else if (b instanceof Serializable) {
1011 s.writeObject(k);
1012 s.writeObject(b);
1013 }
1014 }
1015
1016 /**
1017 * Saves a Serializable listener chain to a serialization stream.
1018 *
1019 * @param s the stream to save to
1020 * @param k a prefix stream to put before each serializable listener
1021 * @param l the listener chain to save
1022 * @throws IOException if serialization fails
1023 */
1024 protected static void save(ObjectOutputStream s, String k, EventListener l) throws IOException {
1025 if (l == null) {
1026 return;
1027 }
1028 else if (l instanceof AWTEventMulticaster) {
1029 ((AWTEventMulticaster)l).saveInternal(s, k);
1030 }
1031 else if (l instanceof Serializable) {
1032 s.writeObject(k);
1033 s.writeObject(l);
1034 }
1035 }
1036
1037 /*
1038 * Recursive method which returns a count of the number of listeners in
1039 * EventListener, handling the (common) case of l actually being an
1040 * AWTEventMulticaster. Additionally, only listeners of type listenerType
1041 * are counted. Method modified to fix bug 4513402. -bchristi
1042 */
1043 private static int getListenerCount(EventListener l, Class<?> listenerType) {
1044 if (l instanceof AWTEventMulticaster) {
1045 AWTEventMulticaster mc = (AWTEventMulticaster)l;
1046 return getListenerCount(mc.a, listenerType) +
1047 getListenerCount(mc.b, listenerType);
1048 }
1049 else {
1050 // Only count listeners of correct type
1051 return listenerType.isInstance(l) ? 1 : 0;
1052 }
1053 }
1054
1055 /*
1056 * Recursive method which populates EventListener array a with EventListeners
1057 * from l. l is usually an AWTEventMulticaster. Bug 4513402 revealed that
1058 * if l differed in type from the element type of a, an ArrayStoreException
1059 * would occur. Now l is only inserted into a if it's of the appropriate
1060 * type. -bchristi
1061 */
1062 private static int populateListenerArray(EventListener[] a, EventListener l, int index) {
1063 if (l instanceof AWTEventMulticaster) {
1064 AWTEventMulticaster mc = (AWTEventMulticaster)l;
1065 int lhs = populateListenerArray(a, mc.a, index);
1066 return populateListenerArray(a, mc.b, lhs);
1067 }
1068 else if (a.getClass().getComponentType().isInstance(l)) {
1069 a[index] = l;
1070 return index + 1;
1071 }
1072 // Skip nulls, instances of wrong class
1073 else {
1074 return index;
1075 }
1076 }
1077
1078 /**
1079 * Returns an array of all the objects chained as
1080 * <code><em>Foo</em>Listener</code>s by the specified
1081 * <code>java.util.EventListener</code>.
1082 * <code><em>Foo</em>Listener</code>s are chained by the
1083 * <code>AWTEventMulticaster</code> using the
1084 * <code>add<em>Foo</em>Listener</code> method.
1085 * If a <code>null</code> listener is specified, this method returns an
1086 * empty array. If the specified listener is not an instance of
1087 * <code>AWTEventMulticaster</code>, this method returns an array which
1088 * contains only the specified listener. If no such listeners are chained,
1089 * this method returns an empty array.
1090 *
1091 * @param l the specified <code>java.util.EventListener</code>
1092 * @param listenerType the type of listeners requested; this parameter
1093 * should specify an interface that descends from
1094 * <code>java.util.EventListener</code>
1095 * @return an array of all objects chained as
1096 * <code><em>Foo</em>Listener</code>s by the specified multicast
1097 * listener, or an empty array if no such listeners have been
1098 * chained by the specified multicast listener
1099 * @exception NullPointerException if the specified
1100 * {@code listenertype} parameter is {@code null}
1101 * @exception ClassCastException if <code>listenerType</code>
1102 * doesn't specify a class or interface that implements
1103 * <code>java.util.EventListener</code>
1104 *
1105 * @since 1.4
1106 */
1107 @SuppressWarnings("unchecked")
1108 public static <T extends EventListener> T[]
1109 getListeners(EventListener l, Class<T> listenerType)
1110 {
1111 if (listenerType == null) {
1112 throw new NullPointerException ("Listener type should not be null");
1113 }
1114
1115 int n = getListenerCount(l, listenerType);
1116 T[] result = (T[])Array.newInstance(listenerType, n);
1117 populateListenerArray(result, l, 0);
1118 return result;
1119 }
1120 }