1 /* 2 * Copyright (c) 1996, 2017, 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.*; 29 30 import java.awt.peer.ComponentPeer; 31 32 import java.lang.ref.WeakReference; 33 import java.lang.reflect.InvocationTargetException; 34 35 import java.security.AccessController; 36 import java.security.PrivilegedAction; 37 38 import java.util.EmptyStackException; 39 40 import sun.awt.*; 41 import sun.awt.dnd.SunDropTargetEvent; 42 import sun.util.logging.PlatformLogger; 43 44 import java.util.concurrent.locks.Condition; 45 import java.util.concurrent.locks.Lock; 46 import java.util.concurrent.atomic.AtomicInteger; 47 48 import java.security.AccessControlContext; 49 50 import jdk.internal.misc.SharedSecrets; 51 import jdk.internal.misc.JavaSecurityAccess; 52 53 /** 54 * {@code EventQueue} is a platform-independent class 55 * that queues events, both from the underlying peer classes 56 * and from trusted application classes. 57 * <p> 58 * It encapsulates asynchronous event dispatch machinery which 59 * extracts events from the queue and dispatches them by calling 60 * {@link #dispatchEvent(AWTEvent) dispatchEvent(AWTEvent)} method 61 * on this {@code EventQueue} with the event to be dispatched 62 * as an argument. The particular behavior of this machinery is 63 * implementation-dependent. The only requirements are that events 64 * which were actually enqueued to this queue (note that events 65 * being posted to the {@code EventQueue} can be coalesced) 66 * are dispatched: 67 * <dl> 68 * <dt> Sequentially. 69 * <dd> That is, it is not permitted that several events from 70 * this queue are dispatched simultaneously. 71 * <dt> In the same order as they are enqueued. 72 * <dd> That is, if {@code AWTEvent} A is enqueued 73 * to the {@code EventQueue} before 74 * {@code AWTEvent} B then event B will not be 75 * dispatched before event A. 76 * </dl> 77 * <p> 78 * Some browsers partition applets in different code bases into 79 * separate contexts, and establish walls between these contexts. 80 * In such a scenario, there will be one {@code EventQueue} 81 * per context. Other browsers place all applets into the same 82 * context, implying that there will be only a single, global 83 * {@code EventQueue} for all applets. This behavior is 84 * implementation-dependent. Consult your browser's documentation 85 * for more information. 86 * <p> 87 * For information on the threading issues of the event dispatch 88 * machinery, see <a href="doc-files/AWTThreadIssues.html#Autoshutdown" 89 * >AWT Threading Issues</a>. 90 * 91 * @author Thomas Ball 92 * @author Fred Ecks 93 * @author David Mendenhall 94 * 95 * @since 1.1 96 */ 97 public class EventQueue { 98 private static final AtomicInteger threadInitNumber = new AtomicInteger(0); 99 100 private static final int LOW_PRIORITY = 0; 101 private static final int NORM_PRIORITY = 1; 102 private static final int HIGH_PRIORITY = 2; 103 private static final int ULTIMATE_PRIORITY = 3; 104 105 private static final int NUM_PRIORITIES = ULTIMATE_PRIORITY + 1; 106 107 /* 108 * We maintain one Queue for each priority that the EventQueue supports. 109 * That is, the EventQueue object is actually implemented as 110 * NUM_PRIORITIES queues and all Events on a particular internal Queue 111 * have identical priority. Events are pulled off the EventQueue starting 112 * with the Queue of highest priority. We progress in decreasing order 113 * across all Queues. 114 */ 115 private Queue[] queues = new Queue[NUM_PRIORITIES]; 116 117 /* 118 * The next EventQueue on the stack, or null if this EventQueue is 119 * on the top of the stack. If nextQueue is non-null, requests to post 120 * an event are forwarded to nextQueue. 121 */ 122 private EventQueue nextQueue; 123 124 /* 125 * The previous EventQueue on the stack, or null if this is the 126 * "base" EventQueue. 127 */ 128 private EventQueue previousQueue; 129 130 /* 131 * A single lock to synchronize the push()/pop() and related operations with 132 * all the EventQueues from the AppContext. Synchronization on any particular 133 * event queue(s) is not enough: we should lock the whole stack. 134 */ 135 private final Lock pushPopLock; 136 private final Condition pushPopCond; 137 138 /* 139 * Dummy runnable to wake up EDT from getNextEvent() after 140 push/pop is performed 141 */ 142 private static final Runnable dummyRunnable = new Runnable() { 143 public void run() { 144 } 145 }; 146 147 private EventDispatchThread dispatchThread; 148 149 private final ThreadGroup threadGroup = 150 Thread.currentThread().getThreadGroup(); 151 private final ClassLoader classLoader = 152 Thread.currentThread().getContextClassLoader(); 153 154 /* 155 * The time stamp of the last dispatched InputEvent or ActionEvent. 156 */ 157 private long mostRecentEventTime = System.currentTimeMillis(); 158 159 /* 160 * The time stamp of the last KeyEvent . 161 */ 162 private long mostRecentKeyEventTime = System.currentTimeMillis(); 163 164 /** 165 * The modifiers field of the current event, if the current event is an 166 * InputEvent or ActionEvent. 167 */ 168 private WeakReference<AWTEvent> currentEvent; 169 170 /* 171 * Non-zero if a thread is waiting in getNextEvent(int) for an event of 172 * a particular ID to be posted to the queue. 173 */ 174 private volatile int waitForID; 175 176 /* 177 * AppContext corresponding to the queue. 178 */ 179 private final AppContext appContext; 180 181 private final String name = "AWT-EventQueue-" + threadInitNumber.getAndIncrement(); 182 183 private FwDispatcher fwDispatcher; 184 185 private static volatile PlatformLogger eventLog; 186 187 private static final PlatformLogger getEventLog() { 188 if(eventLog == null) { 189 eventLog = PlatformLogger.getLogger("java.awt.event.EventQueue"); 190 } 191 return eventLog; 192 } 193 194 static { 195 AWTAccessor.setEventQueueAccessor( 196 new AWTAccessor.EventQueueAccessor() { 197 public Thread getDispatchThread(EventQueue eventQueue) { 198 return eventQueue.getDispatchThread(); 199 } 200 public boolean isDispatchThreadImpl(EventQueue eventQueue) { 201 return eventQueue.isDispatchThreadImpl(); 202 } 203 public void removeSourceEvents(EventQueue eventQueue, 204 Object source, 205 boolean removeAllEvents) 206 { 207 eventQueue.removeSourceEvents(source, removeAllEvents); 208 } 209 public boolean noEvents(EventQueue eventQueue) { 210 return eventQueue.noEvents(); 211 } 212 public void wakeup(EventQueue eventQueue, boolean isShutdown) { 213 eventQueue.wakeup(isShutdown); 214 } 215 public void invokeAndWait(Object source, Runnable r) 216 throws InterruptedException, InvocationTargetException 217 { 218 EventQueue.invokeAndWait(source, r); 219 } 220 public void setFwDispatcher(EventQueue eventQueue, 221 FwDispatcher dispatcher) { 222 eventQueue.setFwDispatcher(dispatcher); 223 } 224 225 @Override 226 public long getMostRecentEventTime(EventQueue eventQueue) { 227 return eventQueue.getMostRecentEventTimeImpl(); 228 } 229 }); 230 } 231 232 /** 233 * Initializes a new instance of {@code EventQueue}. 234 */ 235 public EventQueue() { 236 for (int i = 0; i < NUM_PRIORITIES; i++) { 237 queues[i] = new Queue(); 238 } 239 /* 240 * NOTE: if you ever have to start the associated event dispatch 241 * thread at this point, be aware of the following problem: 242 * If this EventQueue instance is created in 243 * SunToolkit.createNewAppContext() the started dispatch thread 244 * may call AppContext.getAppContext() before createNewAppContext() 245 * completes thus causing mess in thread group to appcontext mapping. 246 */ 247 248 appContext = AppContext.getAppContext(); 249 pushPopLock = (Lock)appContext.get(AppContext.EVENT_QUEUE_LOCK_KEY); 250 pushPopCond = (Condition)appContext.get(AppContext.EVENT_QUEUE_COND_KEY); 251 } 252 253 /** 254 * Posts a 1.1-style event to the {@code EventQueue}. 255 * If there is an existing event on the queue with the same ID 256 * and event source, the source {@code Component}'s 257 * {@code coalesceEvents} method will be called. 258 * 259 * @param theEvent an instance of {@code java.awt.AWTEvent}, 260 * or a subclass of it 261 * @throws NullPointerException if {@code theEvent} is {@code null} 262 */ 263 public void postEvent(AWTEvent theEvent) { 264 SunToolkit.flushPendingEvents(appContext); 265 postEventPrivate(theEvent); 266 } 267 268 /** 269 * Posts a 1.1-style event to the {@code EventQueue}. 270 * If there is an existing event on the queue with the same ID 271 * and event source, the source {@code Component}'s 272 * {@code coalesceEvents} method will be called. 273 * 274 * @param theEvent an instance of {@code java.awt.AWTEvent}, 275 * or a subclass of it 276 */ 277 private final void postEventPrivate(AWTEvent theEvent) { 278 theEvent.isPosted = true; 279 pushPopLock.lock(); 280 try { 281 if (nextQueue != null) { 282 // Forward the event to the top of EventQueue stack 283 nextQueue.postEventPrivate(theEvent); 284 return; 285 } 286 if (dispatchThread == null) { 287 if (theEvent.getSource() == AWTAutoShutdown.getInstance()) { 288 return; 289 } else { 290 initDispatchThread(); 291 } 292 } 293 postEvent(theEvent, getPriority(theEvent)); 294 } finally { 295 pushPopLock.unlock(); 296 } 297 } 298 299 private static int getPriority(AWTEvent theEvent) { 300 if (theEvent instanceof PeerEvent) { 301 PeerEvent peerEvent = (PeerEvent)theEvent; 302 if ((peerEvent.getFlags() & PeerEvent.ULTIMATE_PRIORITY_EVENT) != 0) { 303 return ULTIMATE_PRIORITY; 304 } 305 if ((peerEvent.getFlags() & PeerEvent.PRIORITY_EVENT) != 0) { 306 return HIGH_PRIORITY; 307 } 308 if ((peerEvent.getFlags() & PeerEvent.LOW_PRIORITY_EVENT) != 0) { 309 return LOW_PRIORITY; 310 } 311 } 312 int id = theEvent.getID(); 313 if ((id >= PaintEvent.PAINT_FIRST) && (id <= PaintEvent.PAINT_LAST)) { 314 return LOW_PRIORITY; 315 } 316 return NORM_PRIORITY; 317 } 318 319 /** 320 * Posts the event to the internal Queue of specified priority, 321 * coalescing as appropriate. 322 * 323 * @param theEvent an instance of {@code java.awt.AWTEvent}, 324 * or a subclass of it 325 * @param priority the desired priority of the event 326 */ 327 private void postEvent(AWTEvent theEvent, int priority) { 328 if (coalesceEvent(theEvent, priority)) { 329 return; 330 } 331 332 EventQueueItem newItem = new EventQueueItem(theEvent); 333 334 cacheEQItem(newItem); 335 336 boolean notifyID = (theEvent.getID() == this.waitForID); 337 338 if (queues[priority].head == null) { 339 boolean shouldNotify = noEvents(); 340 queues[priority].head = queues[priority].tail = newItem; 341 342 if (shouldNotify) { 343 if (theEvent.getSource() != AWTAutoShutdown.getInstance()) { 344 AWTAutoShutdown.getInstance().notifyThreadBusy(dispatchThread); 345 } 346 pushPopCond.signalAll(); 347 } else if (notifyID) { 348 pushPopCond.signalAll(); 349 } 350 } else { 351 // The event was not coalesced or has non-Component source. 352 // Insert it at the end of the appropriate Queue. 353 queues[priority].tail.next = newItem; 354 queues[priority].tail = newItem; 355 if (notifyID) { 356 pushPopCond.signalAll(); 357 } 358 } 359 } 360 361 private boolean coalescePaintEvent(PaintEvent e) { 362 ComponentPeer sourcePeer = ((Component)e.getSource()).peer; 363 if (sourcePeer != null) { 364 sourcePeer.coalescePaintEvent(e); 365 } 366 EventQueueItem[] cache = ((Component)e.getSource()).eventCache; 367 if (cache == null) { 368 return false; 369 } 370 int index = eventToCacheIndex(e); 371 372 if (index != -1 && cache[index] != null) { 373 PaintEvent merged = mergePaintEvents(e, (PaintEvent)cache[index].event); 374 if (merged != null) { 375 cache[index].event = merged; 376 return true; 377 } 378 } 379 return false; 380 } 381 382 private PaintEvent mergePaintEvents(PaintEvent a, PaintEvent b) { 383 Rectangle aRect = a.getUpdateRect(); 384 Rectangle bRect = b.getUpdateRect(); 385 if (bRect.contains(aRect)) { 386 return b; 387 } 388 if (aRect.contains(bRect)) { 389 return a; 390 } 391 return null; 392 } 393 394 private boolean coalesceMouseEvent(MouseEvent e) { 395 EventQueueItem[] cache = ((Component)e.getSource()).eventCache; 396 if (cache == null) { 397 return false; 398 } 399 int index = eventToCacheIndex(e); 400 if (index != -1 && cache[index] != null) { 401 cache[index].event = e; 402 return true; 403 } 404 return false; 405 } 406 407 private boolean coalescePeerEvent(PeerEvent e) { 408 EventQueueItem[] cache = ((Component)e.getSource()).eventCache; 409 if (cache == null) { 410 return false; 411 } 412 int index = eventToCacheIndex(e); 413 if (index != -1 && cache[index] != null) { 414 e = e.coalesceEvents((PeerEvent)cache[index].event); 415 if (e != null) { 416 cache[index].event = e; 417 return true; 418 } else { 419 cache[index] = null; 420 } 421 } 422 return false; 423 } 424 425 /* 426 * Should avoid of calling this method by any means 427 * as it's working time is dependant on EQ length. 428 * In the worst case this method alone can slow down the entire application 429 * 10 times by stalling the Event processing. 430 * Only here by backward compatibility reasons. 431 */ 432 private boolean coalesceOtherEvent(AWTEvent e, int priority) { 433 int id = e.getID(); 434 Component source = (Component)e.getSource(); 435 for (EventQueueItem entry = queues[priority].head; 436 entry != null; entry = entry.next) 437 { 438 // Give Component.coalesceEvents a chance 439 if (entry.event.getSource() == source && entry.event.getID() == id) { 440 AWTEvent coalescedEvent = source.coalesceEvents( 441 entry.event, e); 442 if (coalescedEvent != null) { 443 entry.event = coalescedEvent; 444 return true; 445 } 446 } 447 } 448 return false; 449 } 450 451 private boolean coalesceEvent(AWTEvent e, int priority) { 452 if (!(e.getSource() instanceof Component)) { 453 return false; 454 } 455 if (e instanceof PeerEvent) { 456 return coalescePeerEvent((PeerEvent)e); 457 } 458 // The worst case 459 if (((Component)e.getSource()).isCoalescingEnabled() 460 && coalesceOtherEvent(e, priority)) 461 { 462 return true; 463 } 464 if (e instanceof PaintEvent) { 465 return coalescePaintEvent((PaintEvent)e); 466 } 467 if (e instanceof MouseEvent) { 468 return coalesceMouseEvent((MouseEvent)e); 469 } 470 return false; 471 } 472 473 private void cacheEQItem(EventQueueItem entry) { 474 int index = eventToCacheIndex(entry.event); 475 if (index != -1 && entry.event.getSource() instanceof Component) { 476 Component source = (Component)entry.event.getSource(); 477 if (source.eventCache == null) { 478 source.eventCache = new EventQueueItem[CACHE_LENGTH]; 479 } 480 source.eventCache[index] = entry; 481 } 482 } 483 484 private void uncacheEQItem(EventQueueItem entry) { 485 int index = eventToCacheIndex(entry.event); 486 if (index != -1 && entry.event.getSource() instanceof Component) { 487 Component source = (Component)entry.event.getSource(); 488 if (source.eventCache == null) { 489 return; 490 } 491 source.eventCache[index] = null; 492 } 493 } 494 495 private static final int PAINT = 0; 496 private static final int UPDATE = 1; 497 private static final int MOVE = 2; 498 private static final int DRAG = 3; 499 private static final int PEER = 4; 500 private static final int CACHE_LENGTH = 5; 501 502 private static int eventToCacheIndex(AWTEvent e) { 503 switch(e.getID()) { 504 case PaintEvent.PAINT: 505 return PAINT; 506 case PaintEvent.UPDATE: 507 return UPDATE; 508 case MouseEvent.MOUSE_MOVED: 509 return MOVE; 510 case MouseEvent.MOUSE_DRAGGED: 511 // Return -1 for SunDropTargetEvent since they are usually synchronous 512 // and we don't want to skip them by coalescing with MouseEvent or other drag events 513 return e instanceof SunDropTargetEvent ? -1 : DRAG; 514 default: 515 return e instanceof PeerEvent ? PEER : -1; 516 } 517 } 518 519 /** 520 * Returns whether an event is pending on any of the separate 521 * Queues. 522 * @return whether an event is pending on any of the separate Queues 523 */ 524 private boolean noEvents() { 525 for (int i = 0; i < NUM_PRIORITIES; i++) { 526 if (queues[i].head != null) { 527 return false; 528 } 529 } 530 531 return true; 532 } 533 534 /** 535 * Removes an event from the {@code EventQueue} and 536 * returns it. This method will block until an event has 537 * been posted by another thread. 538 * @return the next {@code AWTEvent} 539 * @exception InterruptedException 540 * if any thread has interrupted this thread 541 */ 542 public AWTEvent getNextEvent() throws InterruptedException { 543 do { 544 /* 545 * SunToolkit.flushPendingEvents must be called outside 546 * of the synchronized block to avoid deadlock when 547 * event queues are nested with push()/pop(). 548 */ 549 SunToolkit.flushPendingEvents(appContext); 550 pushPopLock.lock(); 551 try { 552 AWTEvent event = getNextEventPrivate(); 553 if (event != null) { 554 return event; 555 } 556 AWTAutoShutdown.getInstance().notifyThreadFree(dispatchThread); 557 pushPopCond.await(); 558 } finally { 559 pushPopLock.unlock(); 560 } 561 } while(true); 562 } 563 564 /* 565 * Must be called under the lock. Doesn't call flushPendingEvents() 566 */ 567 AWTEvent getNextEventPrivate() throws InterruptedException { 568 for (int i = NUM_PRIORITIES - 1; i >= 0; i--) { 569 if (queues[i].head != null) { 570 EventQueueItem entry = queues[i].head; 571 queues[i].head = entry.next; 572 if (entry.next == null) { 573 queues[i].tail = null; 574 } 575 uncacheEQItem(entry); 576 return entry.event; 577 } 578 } 579 return null; 580 } 581 582 AWTEvent getNextEvent(int id) throws InterruptedException { 583 do { 584 /* 585 * SunToolkit.flushPendingEvents must be called outside 586 * of the synchronized block to avoid deadlock when 587 * event queues are nested with push()/pop(). 588 */ 589 SunToolkit.flushPendingEvents(appContext); 590 pushPopLock.lock(); 591 try { 592 for (int i = 0; i < NUM_PRIORITIES; i++) { 593 for (EventQueueItem entry = queues[i].head, prev = null; 594 entry != null; prev = entry, entry = entry.next) 595 { 596 if (entry.event.getID() == id) { 597 if (prev == null) { 598 queues[i].head = entry.next; 599 } else { 600 prev.next = entry.next; 601 } 602 if (queues[i].tail == entry) { 603 queues[i].tail = prev; 604 } 605 uncacheEQItem(entry); 606 return entry.event; 607 } 608 } 609 } 610 waitForID = id; 611 pushPopCond.await(); 612 waitForID = 0; 613 } finally { 614 pushPopLock.unlock(); 615 } 616 } while(true); 617 } 618 619 /** 620 * Returns the first event on the {@code EventQueue} 621 * without removing it. 622 * @return the first event 623 */ 624 public AWTEvent peekEvent() { 625 pushPopLock.lock(); 626 try { 627 for (int i = NUM_PRIORITIES - 1; i >= 0; i--) { 628 if (queues[i].head != null) { 629 return queues[i].head.event; 630 } 631 } 632 } finally { 633 pushPopLock.unlock(); 634 } 635 636 return null; 637 } 638 639 /** 640 * Returns the first event with the specified id, if any. 641 * @param id the id of the type of event desired 642 * @return the first event of the specified id or {@code null} 643 * if there is no such event 644 */ 645 public AWTEvent peekEvent(int id) { 646 pushPopLock.lock(); 647 try { 648 for (int i = NUM_PRIORITIES - 1; i >= 0; i--) { 649 EventQueueItem q = queues[i].head; 650 for (; q != null; q = q.next) { 651 if (q.event.getID() == id) { 652 return q.event; 653 } 654 } 655 } 656 } finally { 657 pushPopLock.unlock(); 658 } 659 660 return null; 661 } 662 663 private static final JavaSecurityAccess javaSecurityAccess = 664 SharedSecrets.getJavaSecurityAccess(); 665 666 /** 667 * Dispatches an event. The manner in which the event is 668 * dispatched depends upon the type of the event and the 669 * type of the event's source object: 670 * 671 * <table class="striped"> 672 * <caption>Event types, source types, and dispatch methods</caption> 673 * <thead> 674 * <tr> 675 * <th>Event Type</th> 676 * <th>Source Type</th> 677 * <th>Dispatched To</th> 678 * </tr> 679 * </thead> 680 * <tbody> 681 * <tr> 682 * <td>ActiveEvent</td> 683 * <td>Any</td> 684 * <td>event.dispatch()</td> 685 * </tr> 686 * <tr> 687 * <td>Other</td> 688 * <td>Component</td> 689 * <td>source.dispatchEvent(AWTEvent)</td> 690 * </tr> 691 * <tr> 692 * <td>Other</td> 693 * <td>MenuComponent</td> 694 * <td>source.dispatchEvent(AWTEvent)</td> 695 * </tr> 696 * <tr> 697 * <td>Other</td> 698 * <td>Other</td> 699 * <td>No action (ignored)</td> 700 * </tr> 701 * </tbody> 702 * </table> 703 * 704 * @param event an instance of {@code java.awt.AWTEvent}, 705 * or a subclass of it 706 * @throws NullPointerException if {@code event} is {@code null} 707 * @since 1.2 708 */ 709 protected void dispatchEvent(final AWTEvent event) { 710 final Object src = event.getSource(); 711 final PrivilegedAction<Void> action = new PrivilegedAction<Void>() { 712 public Void run() { 713 // In case fwDispatcher is installed and we're already on the 714 // dispatch thread (e.g. performing DefaultKeyboardFocusManager.sendMessage), 715 // dispatch the event straight away. 716 if (fwDispatcher == null || isDispatchThreadImpl()) { 717 dispatchEventImpl(event, src); 718 } else { 719 fwDispatcher.scheduleDispatch(new Runnable() { 720 @Override 721 public void run() { 722 dispatchEventImpl(event, src); 723 } 724 }); 725 } 726 return null; 727 } 728 }; 729 730 final AccessControlContext stack = AccessController.getContext(); 731 final AccessControlContext srcAcc = getAccessControlContextFrom(src); 732 final AccessControlContext eventAcc = event.getAccessControlContext(); 733 if (srcAcc == null) { 734 javaSecurityAccess.doIntersectionPrivilege(action, stack, eventAcc); 735 } else { 736 javaSecurityAccess.doIntersectionPrivilege( 737 new PrivilegedAction<Void>() { 738 public Void run() { 739 javaSecurityAccess.doIntersectionPrivilege(action, eventAcc); 740 return null; 741 } 742 }, stack, srcAcc); 743 } 744 } 745 746 private static AccessControlContext getAccessControlContextFrom(Object src) { 747 return src instanceof Component ? 748 ((Component)src).getAccessControlContext() : 749 src instanceof MenuComponent ? 750 ((MenuComponent)src).getAccessControlContext() : 751 src instanceof TrayIcon ? 752 ((TrayIcon)src).getAccessControlContext() : 753 null; 754 } 755 756 /** 757 * Called from dispatchEvent() under a correct AccessControlContext 758 */ 759 private void dispatchEventImpl(final AWTEvent event, final Object src) { 760 event.isPosted = true; 761 if (event instanceof ActiveEvent) { 762 // This could become the sole method of dispatching in time. 763 setCurrentEventAndMostRecentTimeImpl(event); 764 ((ActiveEvent)event).dispatch(); 765 } else if (src instanceof Component) { 766 ((Component)src).dispatchEvent(event); 767 event.dispatched(); 768 } else if (src instanceof MenuComponent) { 769 ((MenuComponent)src).dispatchEvent(event); 770 } else if (src instanceof TrayIcon) { 771 ((TrayIcon)src).dispatchEvent(event); 772 } else if (src instanceof AWTAutoShutdown) { 773 if (noEvents()) { 774 dispatchThread.stopDispatching(); 775 } 776 } else { 777 if (getEventLog().isLoggable(PlatformLogger.Level.FINE)) { 778 getEventLog().fine("Unable to dispatch event: " + event); 779 } 780 } 781 } 782 783 /** 784 * Returns the timestamp of the most recent event that had a timestamp, and 785 * that was dispatched from the {@code EventQueue} associated with the 786 * calling thread. If an event with a timestamp is currently being 787 * dispatched, its timestamp will be returned. If no events have yet 788 * been dispatched, the EventQueue's initialization time will be 789 * returned instead.In the current version of 790 * the JDK, only {@code InputEvent}s, 791 * {@code ActionEvent}s, and {@code InvocationEvent}s have 792 * timestamps; however, future versions of the JDK may add timestamps to 793 * additional event types. Note that this method should only be invoked 794 * from an application's {@link #isDispatchThread event dispatching thread}. 795 * If this method is 796 * invoked from another thread, the current system time (as reported by 797 * {@code System.currentTimeMillis()}) will be returned instead. 798 * 799 * @return the timestamp of the last {@code InputEvent}, 800 * {@code ActionEvent}, or {@code InvocationEvent} to be 801 * dispatched, or {@code System.currentTimeMillis()} if this 802 * method is invoked on a thread other than an event dispatching 803 * thread 804 * @see java.awt.event.InputEvent#getWhen 805 * @see java.awt.event.ActionEvent#getWhen 806 * @see java.awt.event.InvocationEvent#getWhen 807 * @see #isDispatchThread 808 * 809 * @since 1.4 810 */ 811 public static long getMostRecentEventTime() { 812 return Toolkit.getEventQueue().getMostRecentEventTimeImpl(); 813 } 814 private long getMostRecentEventTimeImpl() { 815 pushPopLock.lock(); 816 try { 817 return (Thread.currentThread() == dispatchThread) 818 ? mostRecentEventTime 819 : System.currentTimeMillis(); 820 } finally { 821 pushPopLock.unlock(); 822 } 823 } 824 825 /** 826 * @return most recent event time on all threads. 827 */ 828 long getMostRecentEventTimeEx() { 829 pushPopLock.lock(); 830 try { 831 return mostRecentEventTime; 832 } finally { 833 pushPopLock.unlock(); 834 } 835 } 836 837 /** 838 * Returns the event currently being dispatched by the 839 * {@code EventQueue} associated with the calling thread. This is 840 * useful if a method needs access to the event, but was not designed to 841 * receive a reference to it as an argument. Note that this method should 842 * only be invoked from an application's event dispatching thread. If this 843 * method is invoked from another thread, null will be returned. 844 * 845 * @return the event currently being dispatched, or null if this method is 846 * invoked on a thread other than an event dispatching thread 847 * @since 1.4 848 */ 849 public static AWTEvent getCurrentEvent() { 850 return Toolkit.getEventQueue().getCurrentEventImpl(); 851 } 852 private AWTEvent getCurrentEventImpl() { 853 pushPopLock.lock(); 854 try { 855 return (Thread.currentThread() == dispatchThread) 856 ? currentEvent.get() 857 : null; 858 } finally { 859 pushPopLock.unlock(); 860 } 861 } 862 863 /** 864 * Replaces the existing {@code EventQueue} with the specified one. 865 * Any pending events are transferred to the new {@code EventQueue} 866 * for processing by it. 867 * 868 * @param newEventQueue an {@code EventQueue} 869 * (or subclass thereof) instance to be use 870 * @see java.awt.EventQueue#pop 871 * @throws NullPointerException if {@code newEventQueue} is {@code null} 872 * @since 1.2 873 */ 874 public void push(EventQueue newEventQueue) { 875 if (getEventLog().isLoggable(PlatformLogger.Level.FINE)) { 876 getEventLog().fine("EventQueue.push(" + newEventQueue + ")"); 877 } 878 879 pushPopLock.lock(); 880 try { 881 EventQueue topQueue = this; 882 while (topQueue.nextQueue != null) { 883 topQueue = topQueue.nextQueue; 884 } 885 if (topQueue.fwDispatcher != null) { 886 throw new RuntimeException("push() to queue with fwDispatcher"); 887 } 888 if ((topQueue.dispatchThread != null) && 889 (topQueue.dispatchThread.getEventQueue() == this)) 890 { 891 newEventQueue.dispatchThread = topQueue.dispatchThread; 892 topQueue.dispatchThread.setEventQueue(newEventQueue); 893 } 894 895 // Transfer all events forward to new EventQueue. 896 while (topQueue.peekEvent() != null) { 897 try { 898 // Use getNextEventPrivate() as it doesn't call flushPendingEvents() 899 newEventQueue.postEventPrivate(topQueue.getNextEventPrivate()); 900 } catch (InterruptedException ie) { 901 if (getEventLog().isLoggable(PlatformLogger.Level.FINE)) { 902 getEventLog().fine("Interrupted push", ie); 903 } 904 } 905 } 906 907 if (topQueue.dispatchThread != null) { 908 // Wake up EDT waiting in getNextEvent(), so it can 909 // pick up a new EventQueue. Post the waking event before 910 // topQueue.nextQueue is assigned, otherwise the event would 911 // go newEventQueue 912 topQueue.postEventPrivate(new InvocationEvent(topQueue, dummyRunnable)); 913 } 914 915 newEventQueue.previousQueue = topQueue; 916 topQueue.nextQueue = newEventQueue; 917 918 if (appContext.get(AppContext.EVENT_QUEUE_KEY) == topQueue) { 919 appContext.put(AppContext.EVENT_QUEUE_KEY, newEventQueue); 920 } 921 922 pushPopCond.signalAll(); 923 } finally { 924 pushPopLock.unlock(); 925 } 926 } 927 928 /** 929 * Stops dispatching events using this {@code EventQueue}. 930 * Any pending events are transferred to the previous 931 * {@code EventQueue} for processing. 932 * <p> 933 * Warning: To avoid deadlock, do not declare this method 934 * synchronized in a subclass. 935 * 936 * @exception EmptyStackException if no previous push was made 937 * on this {@code EventQueue} 938 * @see java.awt.EventQueue#push 939 * @since 1.2 940 */ 941 protected void pop() throws EmptyStackException { 942 if (getEventLog().isLoggable(PlatformLogger.Level.FINE)) { 943 getEventLog().fine("EventQueue.pop(" + this + ")"); 944 } 945 946 pushPopLock.lock(); 947 try { 948 EventQueue topQueue = this; 949 while (topQueue.nextQueue != null) { 950 topQueue = topQueue.nextQueue; 951 } 952 EventQueue prevQueue = topQueue.previousQueue; 953 if (prevQueue == null) { 954 throw new EmptyStackException(); 955 } 956 957 topQueue.previousQueue = null; 958 prevQueue.nextQueue = null; 959 960 // Transfer all events back to previous EventQueue. 961 while (topQueue.peekEvent() != null) { 962 try { 963 prevQueue.postEventPrivate(topQueue.getNextEventPrivate()); 964 } catch (InterruptedException ie) { 965 if (getEventLog().isLoggable(PlatformLogger.Level.FINE)) { 966 getEventLog().fine("Interrupted pop", ie); 967 } 968 } 969 } 970 971 if ((topQueue.dispatchThread != null) && 972 (topQueue.dispatchThread.getEventQueue() == this)) 973 { 974 prevQueue.dispatchThread = topQueue.dispatchThread; 975 topQueue.dispatchThread.setEventQueue(prevQueue); 976 } 977 978 if (appContext.get(AppContext.EVENT_QUEUE_KEY) == this) { 979 appContext.put(AppContext.EVENT_QUEUE_KEY, prevQueue); 980 } 981 982 // Wake up EDT waiting in getNextEvent(), so it can 983 // pick up a new EventQueue 984 topQueue.postEventPrivate(new InvocationEvent(topQueue, dummyRunnable)); 985 986 pushPopCond.signalAll(); 987 } finally { 988 pushPopLock.unlock(); 989 } 990 } 991 992 /** 993 * Creates a new {@code secondary loop} associated with this 994 * event queue. Use the {@link SecondaryLoop#enter} and 995 * {@link SecondaryLoop#exit} methods to start and stop the 996 * event loop and dispatch the events from this queue. 997 * 998 * @return secondaryLoop A new secondary loop object, which can 999 * be used to launch a new nested event 1000 * loop and dispatch events from this queue 1001 * 1002 * @see SecondaryLoop#enter 1003 * @see SecondaryLoop#exit 1004 * 1005 * @since 1.7 1006 */ 1007 public SecondaryLoop createSecondaryLoop() { 1008 return createSecondaryLoop(null, null, 0); 1009 } 1010 1011 SecondaryLoop createSecondaryLoop(Conditional cond, EventFilter filter, long interval) { 1012 pushPopLock.lock(); 1013 try { 1014 if (nextQueue != null) { 1015 // Forward the request to the top of EventQueue stack 1016 return nextQueue.createSecondaryLoop(cond, filter, interval); 1017 } 1018 if (fwDispatcher != null) { 1019 return fwDispatcher.createSecondaryLoop(); 1020 } 1021 if (dispatchThread == null) { 1022 initDispatchThread(); 1023 } 1024 return new WaitDispatchSupport(dispatchThread, cond, filter, interval); 1025 } finally { 1026 pushPopLock.unlock(); 1027 } 1028 } 1029 1030 /** 1031 * Returns true if the calling thread is 1032 * {@link Toolkit#getSystemEventQueue the current AWT EventQueue}'s 1033 * dispatch thread. Use this method to ensure that a particular 1034 * task is being executed (or not being) there. 1035 * <p> 1036 * Note: use the {@link #invokeLater} or {@link #invokeAndWait} 1037 * methods to execute a task in 1038 * {@link Toolkit#getSystemEventQueue the current AWT EventQueue}'s 1039 * dispatch thread. 1040 * 1041 * @return true if running in 1042 * {@link Toolkit#getSystemEventQueue the current AWT EventQueue}'s 1043 * dispatch thread 1044 * @see #invokeLater 1045 * @see #invokeAndWait 1046 * @see Toolkit#getSystemEventQueue 1047 * @since 1.2 1048 */ 1049 public static boolean isDispatchThread() { 1050 EventQueue eq = Toolkit.getEventQueue(); 1051 return eq.isDispatchThreadImpl(); 1052 } 1053 1054 final boolean isDispatchThreadImpl() { 1055 EventQueue eq = this; 1056 pushPopLock.lock(); 1057 try { 1058 EventQueue next = eq.nextQueue; 1059 while (next != null) { 1060 eq = next; 1061 next = eq.nextQueue; 1062 } 1063 if (eq.fwDispatcher != null) { 1064 return eq.fwDispatcher.isDispatchThread(); 1065 } 1066 return (Thread.currentThread() == eq.dispatchThread); 1067 } finally { 1068 pushPopLock.unlock(); 1069 } 1070 } 1071 1072 final void initDispatchThread() { 1073 pushPopLock.lock(); 1074 try { 1075 if (dispatchThread == null && !threadGroup.isDestroyed() && !appContext.isDisposed()) { 1076 dispatchThread = AccessController.doPrivileged( 1077 new PrivilegedAction<EventDispatchThread>() { 1078 public EventDispatchThread run() { 1079 EventDispatchThread t = 1080 new EventDispatchThread(threadGroup, 1081 name, 1082 EventQueue.this); 1083 t.setContextClassLoader(classLoader); 1084 t.setPriority(Thread.NORM_PRIORITY + 1); 1085 t.setDaemon(false); 1086 AWTAutoShutdown.getInstance().notifyThreadBusy(t); 1087 return t; 1088 } 1089 } 1090 ); 1091 dispatchThread.start(); 1092 } 1093 } finally { 1094 pushPopLock.unlock(); 1095 } 1096 } 1097 1098 final void detachDispatchThread(EventDispatchThread edt) { 1099 /* 1100 * Minimize discard possibility for non-posted events 1101 */ 1102 SunToolkit.flushPendingEvents(appContext); 1103 /* 1104 * This synchronized block is to secure that the event dispatch 1105 * thread won't die in the middle of posting a new event to the 1106 * associated event queue. It is important because we notify 1107 * that the event dispatch thread is busy after posting a new event 1108 * to its queue, so the EventQueue.dispatchThread reference must 1109 * be valid at that point. 1110 */ 1111 pushPopLock.lock(); 1112 try { 1113 if (edt == dispatchThread) { 1114 dispatchThread = null; 1115 } 1116 AWTAutoShutdown.getInstance().notifyThreadFree(edt); 1117 /* 1118 * Event was posted after EDT events pumping had stopped, so start 1119 * another EDT to handle this event 1120 */ 1121 if (peekEvent() != null) { 1122 initDispatchThread(); 1123 } 1124 } finally { 1125 pushPopLock.unlock(); 1126 } 1127 } 1128 1129 /* 1130 * Gets the {@code EventDispatchThread} for this 1131 * {@code EventQueue}. 1132 * @return the event dispatch thread associated with this event queue 1133 * or {@code null} if this event queue doesn't have a 1134 * working thread associated with it 1135 * @see java.awt.EventQueue#initDispatchThread 1136 * @see java.awt.EventQueue#detachDispatchThread 1137 */ 1138 final EventDispatchThread getDispatchThread() { 1139 pushPopLock.lock(); 1140 try { 1141 return dispatchThread; 1142 } finally { 1143 pushPopLock.unlock(); 1144 } 1145 } 1146 1147 /* 1148 * Removes any pending events for the specified source object. 1149 * If removeAllEvents parameter is {@code true} then all 1150 * events for the specified source object are removed, if it 1151 * is {@code false} then {@code SequencedEvent}, {@code SentEvent}, 1152 * {@code FocusEvent}, {@code WindowEvent}, {@code KeyEvent}, 1153 * and {@code InputMethodEvent} are kept in the queue, but all other 1154 * events are removed. 1155 * 1156 * This method is normally called by the source's 1157 * {@code removeNotify} method. 1158 */ 1159 final void removeSourceEvents(Object source, boolean removeAllEvents) { 1160 SunToolkit.flushPendingEvents(appContext); 1161 pushPopLock.lock(); 1162 try { 1163 for (int i = 0; i < NUM_PRIORITIES; i++) { 1164 EventQueueItem entry = queues[i].head; 1165 EventQueueItem prev = null; 1166 while (entry != null) { 1167 if ((entry.event.getSource() == source) 1168 && (removeAllEvents 1169 || ! (entry.event instanceof SequencedEvent 1170 || entry.event instanceof SentEvent 1171 || entry.event instanceof FocusEvent 1172 || entry.event instanceof WindowEvent 1173 || entry.event instanceof KeyEvent 1174 || entry.event instanceof InputMethodEvent))) 1175 { 1176 if (entry.event instanceof SequencedEvent) { 1177 ((SequencedEvent)entry.event).dispose(); 1178 } 1179 if (entry.event instanceof SentEvent) { 1180 ((SentEvent)entry.event).dispose(); 1181 } 1182 if (entry.event instanceof InvocationEvent) { 1183 AWTAccessor.getInvocationEventAccessor() 1184 .dispose((InvocationEvent)entry.event); 1185 } 1186 if (prev == null) { 1187 queues[i].head = entry.next; 1188 } else { 1189 prev.next = entry.next; 1190 } 1191 uncacheEQItem(entry); 1192 } else { 1193 prev = entry; 1194 } 1195 entry = entry.next; 1196 } 1197 queues[i].tail = prev; 1198 } 1199 } finally { 1200 pushPopLock.unlock(); 1201 } 1202 } 1203 1204 synchronized long getMostRecentKeyEventTime() { 1205 pushPopLock.lock(); 1206 try { 1207 return mostRecentKeyEventTime; 1208 } finally { 1209 pushPopLock.unlock(); 1210 } 1211 } 1212 1213 static void setCurrentEventAndMostRecentTime(AWTEvent e) { 1214 Toolkit.getEventQueue().setCurrentEventAndMostRecentTimeImpl(e); 1215 } 1216 private void setCurrentEventAndMostRecentTimeImpl(AWTEvent e) { 1217 pushPopLock.lock(); 1218 try { 1219 if (Thread.currentThread() != dispatchThread) { 1220 return; 1221 } 1222 1223 currentEvent = new WeakReference<>(e); 1224 1225 // This series of 'instanceof' checks should be replaced with a 1226 // polymorphic type (for example, an interface which declares a 1227 // getWhen() method). However, this would require us to make such 1228 // a type public, or to place it in sun.awt. Both of these approaches 1229 // have been frowned upon. So for now, we hack. 1230 // 1231 // In tiger, we will probably give timestamps to all events, so this 1232 // will no longer be an issue. 1233 long mostRecentEventTime2 = Long.MIN_VALUE; 1234 if (e instanceof InputEvent) { 1235 InputEvent ie = (InputEvent)e; 1236 mostRecentEventTime2 = ie.getWhen(); 1237 if (e instanceof KeyEvent) { 1238 mostRecentKeyEventTime = ie.getWhen(); 1239 } 1240 } else if (e instanceof InputMethodEvent) { 1241 InputMethodEvent ime = (InputMethodEvent)e; 1242 mostRecentEventTime2 = ime.getWhen(); 1243 } else if (e instanceof ActionEvent) { 1244 ActionEvent ae = (ActionEvent)e; 1245 mostRecentEventTime2 = ae.getWhen(); 1246 } else if (e instanceof InvocationEvent) { 1247 InvocationEvent ie = (InvocationEvent)e; 1248 mostRecentEventTime2 = ie.getWhen(); 1249 } 1250 mostRecentEventTime = Math.max(mostRecentEventTime, mostRecentEventTime2); 1251 } finally { 1252 pushPopLock.unlock(); 1253 } 1254 } 1255 1256 /** 1257 * Causes {@code runnable} to have its {@code run} 1258 * method called in the {@link #isDispatchThread dispatch thread} of 1259 * {@link Toolkit#getSystemEventQueue the system EventQueue}. 1260 * This will happen after all pending events are processed. 1261 * 1262 * @param runnable the {@code Runnable} whose {@code run} 1263 * method should be executed 1264 * asynchronously in the 1265 * {@link #isDispatchThread event dispatch thread} 1266 * of {@link Toolkit#getSystemEventQueue the system EventQueue} 1267 * @see #invokeAndWait 1268 * @see Toolkit#getSystemEventQueue 1269 * @see #isDispatchThread 1270 * @since 1.2 1271 */ 1272 public static void invokeLater(Runnable runnable) { 1273 Toolkit.getEventQueue().postEvent( 1274 new InvocationEvent(Toolkit.getDefaultToolkit(), runnable)); 1275 } 1276 1277 /** 1278 * Causes {@code runnable} to have its {@code run} 1279 * method called in the {@link #isDispatchThread dispatch thread} of 1280 * {@link Toolkit#getSystemEventQueue the system EventQueue}. 1281 * This will happen after all pending events are processed. 1282 * The call blocks until this has happened. This method 1283 * will throw an Error if called from the 1284 * {@link #isDispatchThread event dispatcher thread}. 1285 * 1286 * @param runnable the {@code Runnable} whose {@code run} 1287 * method should be executed 1288 * synchronously in the 1289 * {@link #isDispatchThread event dispatch thread} 1290 * of {@link Toolkit#getSystemEventQueue the system EventQueue} 1291 * @exception InterruptedException if any thread has 1292 * interrupted this thread 1293 * @exception InvocationTargetException if an throwable is thrown 1294 * when running {@code runnable} 1295 * @see #invokeLater 1296 * @see Toolkit#getSystemEventQueue 1297 * @see #isDispatchThread 1298 * @since 1.2 1299 */ 1300 public static void invokeAndWait(Runnable runnable) 1301 throws InterruptedException, InvocationTargetException 1302 { 1303 invokeAndWait(Toolkit.getDefaultToolkit(), runnable); 1304 } 1305 1306 static void invokeAndWait(Object source, Runnable runnable) 1307 throws InterruptedException, InvocationTargetException 1308 { 1309 if (EventQueue.isDispatchThread()) { 1310 throw new Error("Cannot call invokeAndWait from the event dispatcher thread"); 1311 } 1312 1313 class AWTInvocationLock {} 1314 Object lock = new AWTInvocationLock(); 1315 1316 InvocationEvent event = 1317 new InvocationEvent(source, runnable, lock, true); 1318 1319 synchronized (lock) { 1320 Toolkit.getEventQueue().postEvent(event); 1321 while (!event.isDispatched()) { 1322 lock.wait(); 1323 } 1324 } 1325 1326 Throwable eventThrowable = event.getThrowable(); 1327 if (eventThrowable != null) { 1328 throw new InvocationTargetException(eventThrowable); 1329 } 1330 } 1331 1332 /* 1333 * Called from PostEventQueue.postEvent to notify that a new event 1334 * appeared. First it proceeds to the EventQueue on the top of the 1335 * stack, then notifies the associated dispatch thread if it exists 1336 * or starts a new one otherwise. 1337 */ 1338 private void wakeup(boolean isShutdown) { 1339 pushPopLock.lock(); 1340 try { 1341 if (nextQueue != null) { 1342 // Forward call to the top of EventQueue stack. 1343 nextQueue.wakeup(isShutdown); 1344 } else if (dispatchThread != null) { 1345 pushPopCond.signalAll(); 1346 } else if (!isShutdown) { 1347 initDispatchThread(); 1348 } 1349 } finally { 1350 pushPopLock.unlock(); 1351 } 1352 } 1353 1354 // The method is used by AWTAccessor for javafx/AWT single threaded mode. 1355 private void setFwDispatcher(FwDispatcher dispatcher) { 1356 if (nextQueue != null) { 1357 nextQueue.setFwDispatcher(dispatcher); 1358 } else { 1359 fwDispatcher = dispatcher; 1360 } 1361 } 1362 } 1363 1364 /** 1365 * The Queue object holds pointers to the beginning and end of one internal 1366 * queue. An EventQueue object is composed of multiple internal Queues, one 1367 * for each priority supported by the EventQueue. All Events on a particular 1368 * internal Queue have identical priority. 1369 */ 1370 class Queue { 1371 EventQueueItem head; 1372 EventQueueItem tail; 1373 }