J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1996-2007 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package java.awt; |
| 27 | |
| 28 | import java.awt.event.InputEvent; |
| 29 | import java.awt.event.MouseEvent; |
| 30 | import java.awt.event.ActionEvent; |
| 31 | import java.awt.event.WindowEvent; |
| 32 | import java.lang.reflect.Method; |
| 33 | import java.security.AccessController; |
| 34 | import sun.security.action.GetPropertyAction; |
| 35 | import sun.awt.AWTAutoShutdown; |
| 36 | import sun.awt.SunToolkit; |
| 37 | |
| 38 | import java.util.Vector; |
| 39 | import java.util.logging.*; |
| 40 | |
| 41 | import sun.awt.dnd.SunDragSourceContextPeer; |
| 42 | |
| 43 | /** |
| 44 | * EventDispatchThread is a package-private AWT class which takes |
| 45 | * events off the EventQueue and dispatches them to the appropriate |
| 46 | * AWT components. |
| 47 | * |
| 48 | * The Thread starts a "permanent" event pump with a call to |
| 49 | * pumpEvents(Conditional) in its run() method. Event handlers can choose to |
| 50 | * block this event pump at any time, but should start a new pump (<b>not</b> |
| 51 | * a new EventDispatchThread) by again calling pumpEvents(Conditional). This |
| 52 | * secondary event pump will exit automatically as soon as the Condtional |
| 53 | * evaluate()s to false and an additional Event is pumped and dispatched. |
| 54 | * |
| 55 | * @author Tom Ball |
| 56 | * @author Amy Fowler |
| 57 | * @author Fred Ecks |
| 58 | * @author David Mendenhall |
| 59 | * |
| 60 | * @since 1.1 |
| 61 | */ |
| 62 | class EventDispatchThread extends Thread { |
| 63 | private static final Logger eventLog = Logger.getLogger("java.awt.event.EventDispatchThread"); |
| 64 | |
| 65 | private EventQueue theQueue; |
| 66 | private boolean doDispatch = true; |
| 67 | private static final int ANY_EVENT = -1; |
| 68 | |
| 69 | private Vector<EventFilter> eventFilters = new Vector<EventFilter>(); |
| 70 | // used in handleException |
| 71 | private int modalFiltersCount = 0; |
| 72 | |
| 73 | EventDispatchThread(ThreadGroup group, String name, EventQueue queue) { |
| 74 | super(group, name); |
| 75 | theQueue = queue; |
| 76 | } |
| 77 | |
| 78 | void stopDispatchingImpl(boolean wait) { |
| 79 | // Note: We stop dispatching via a flag rather than using |
| 80 | // Thread.interrupt() because we can't guarantee that the wait() |
| 81 | // we interrupt will be EventQueue.getNextEvent()'s. -fredx 8-11-98 |
| 82 | |
| 83 | StopDispatchEvent stopEvent = new StopDispatchEvent(); |
| 84 | |
| 85 | // wait for the dispatcher to complete |
| 86 | if (Thread.currentThread() != this) { |
| 87 | |
| 88 | // fix 4122683, 4128923 |
| 89 | // Post an empty event to ensure getNextEvent is unblocked |
| 90 | // |
| 91 | // We have to use postEventPrivate instead of postEvent because |
| 92 | // EventQueue.pop calls EventDispatchThread.stopDispatching. |
| 93 | // Calling SunToolkit.flushPendingEvents in this case could |
| 94 | // lead to deadlock. |
| 95 | theQueue.postEventPrivate(stopEvent); |
| 96 | |
| 97 | if (wait) { |
| 98 | try { |
| 99 | join(); |
| 100 | } catch(InterruptedException e) { |
| 101 | } |
| 102 | } |
| 103 | } else { |
| 104 | stopEvent.dispatch(); |
| 105 | } |
| 106 | synchronized (theQueue) { |
| 107 | if (theQueue.getDispatchThread() == this) { |
| 108 | theQueue.detachDispatchThread(); |
| 109 | } |
| 110 | } |
| 111 | } |
| 112 | |
| 113 | public void stopDispatching() { |
| 114 | stopDispatchingImpl(true); |
| 115 | } |
| 116 | |
| 117 | public void stopDispatchingLater() { |
| 118 | stopDispatchingImpl(false); |
| 119 | } |
| 120 | |
| 121 | class StopDispatchEvent extends AWTEvent implements ActiveEvent { |
| 122 | /* |
| 123 | * serialVersionUID |
| 124 | */ |
| 125 | static final long serialVersionUID = -3692158172100730735L; |
| 126 | |
| 127 | public StopDispatchEvent() { |
| 128 | super(EventDispatchThread.this,0); |
| 129 | } |
| 130 | |
| 131 | public void dispatch() { |
| 132 | doDispatch = false; |
| 133 | } |
| 134 | } |
| 135 | |
| 136 | public void run() { |
| 137 | try { |
| 138 | pumpEvents(new Conditional() { |
| 139 | public boolean evaluate() { |
| 140 | return true; |
| 141 | } |
| 142 | }); |
| 143 | } finally { |
| 144 | /* |
| 145 | * This synchronized block is to secure that the event dispatch |
| 146 | * thread won't die in the middle of posting a new event to the |
| 147 | * associated event queue. It is important because we notify |
| 148 | * that the event dispatch thread is busy after posting a new event |
| 149 | * to its queue, so the EventQueue.dispatchThread reference must |
| 150 | * be valid at that point. |
| 151 | */ |
| 152 | synchronized (theQueue) { |
| 153 | if (theQueue.getDispatchThread() == this) { |
| 154 | theQueue.detachDispatchThread(); |
| 155 | } |
| 156 | /* |
| 157 | * Event dispatch thread dies in case of an uncaught exception. |
| 158 | * A new event dispatch thread for this queue will be started |
| 159 | * only if a new event is posted to it. In case if no more |
| 160 | * events are posted after this thread died all events that |
| 161 | * currently are in the queue will never be dispatched. |
| 162 | */ |
| 163 | /* |
| 164 | * Fix for 4648733. Check both the associated java event |
| 165 | * queue and the PostEventQueue. |
| 166 | */ |
| 167 | if (theQueue.peekEvent() != null || |
| 168 | !SunToolkit.isPostEventQueueEmpty()) { |
| 169 | theQueue.initDispatchThread(); |
| 170 | } |
| 171 | AWTAutoShutdown.getInstance().notifyThreadFree(this); |
| 172 | } |
| 173 | } |
| 174 | } |
| 175 | |
| 176 | void pumpEvents(Conditional cond) { |
| 177 | pumpEvents(ANY_EVENT, cond); |
| 178 | } |
| 179 | |
| 180 | void pumpEventsForHierarchy(Conditional cond, Component modalComponent) { |
| 181 | pumpEventsForHierarchy(ANY_EVENT, cond, modalComponent); |
| 182 | } |
| 183 | |
| 184 | void pumpEvents(int id, Conditional cond) { |
| 185 | pumpEventsForHierarchy(id, cond, null); |
| 186 | } |
| 187 | |
| 188 | void pumpEventsForHierarchy(int id, Conditional cond, Component modalComponent) |
| 189 | { |
| 190 | pumpEventsForFilter(id, cond, new HierarchyEventFilter(modalComponent)); |
| 191 | } |
| 192 | |
| 193 | void pumpEventsForFilter(Conditional cond, EventFilter filter) { |
| 194 | pumpEventsForFilter(ANY_EVENT, cond, filter); |
| 195 | } |
| 196 | |
| 197 | void pumpEventsForFilter(int id, Conditional cond, EventFilter filter) { |
| 198 | addEventFilter(filter); |
| 199 | while (doDispatch && cond.evaluate()) { |
| 200 | if (isInterrupted() || !pumpOneEventForFilters(id)) { |
| 201 | doDispatch = false; |
| 202 | } |
| 203 | } |
| 204 | removeEventFilter(filter); |
| 205 | } |
| 206 | |
| 207 | void addEventFilter(EventFilter filter) { |
| 208 | synchronized (eventFilters) { |
| 209 | if (!eventFilters.contains(filter)) { |
| 210 | if (filter instanceof ModalEventFilter) { |
| 211 | ModalEventFilter newFilter = (ModalEventFilter)filter; |
| 212 | int k = 0; |
| 213 | for (k = 0; k < eventFilters.size(); k++) { |
| 214 | EventFilter f = eventFilters.get(k); |
| 215 | if (f instanceof ModalEventFilter) { |
| 216 | ModalEventFilter cf = (ModalEventFilter)f; |
| 217 | if (cf.compareTo(newFilter) > 0) { |
| 218 | break; |
| 219 | } |
| 220 | } |
| 221 | } |
| 222 | eventFilters.add(k, filter); |
| 223 | modalFiltersCount++; |
| 224 | } else { |
| 225 | eventFilters.add(filter); |
| 226 | } |
| 227 | } |
| 228 | } |
| 229 | } |
| 230 | |
| 231 | void removeEventFilter(EventFilter filter) { |
| 232 | synchronized (eventFilters) { |
| 233 | if (eventFilters.contains(filter)) { |
| 234 | if (filter instanceof ModalEventFilter) { |
| 235 | modalFiltersCount--; |
| 236 | } |
| 237 | eventFilters.remove(filter); |
| 238 | } |
| 239 | } |
| 240 | } |
| 241 | |
| 242 | boolean pumpOneEventForFilters(int id) { |
| 243 | try { |
| 244 | AWTEvent event; |
| 245 | boolean eventOK; |
| 246 | do { |
| 247 | event = (id == ANY_EVENT) |
| 248 | ? theQueue.getNextEvent() |
| 249 | : theQueue.getNextEvent(id); |
| 250 | |
| 251 | eventOK = true; |
| 252 | synchronized (eventFilters) { |
| 253 | for (int i = eventFilters.size() - 1; i >= 0; i--) { |
| 254 | EventFilter f = eventFilters.get(i); |
| 255 | EventFilter.FilterAction accept = f.acceptEvent(event); |
| 256 | if (accept == EventFilter.FilterAction.REJECT) { |
| 257 | eventOK = false; |
| 258 | break; |
| 259 | } else if (accept == EventFilter.FilterAction.ACCEPT_IMMEDIATELY) { |
| 260 | break; |
| 261 | } |
| 262 | } |
| 263 | } |
| 264 | eventOK = eventOK && SunDragSourceContextPeer.checkEvent(event); |
| 265 | if (!eventOK) { |
| 266 | event.consume(); |
| 267 | } |
| 268 | } |
| 269 | while (eventOK == false); |
| 270 | |
| 271 | if (eventLog.isLoggable(Level.FINEST)) { |
| 272 | eventLog.log(Level.FINEST, "Dispatching: " + event); |
| 273 | } |
| 274 | |
| 275 | theQueue.dispatchEvent(event); |
| 276 | return true; |
| 277 | } |
| 278 | catch (ThreadDeath death) { |
| 279 | return false; |
| 280 | |
| 281 | } |
| 282 | catch (InterruptedException interruptedException) { |
| 283 | return false; // AppContext.dispose() interrupts all |
| 284 | // Threads in the AppContext |
| 285 | |
| 286 | } |
| 287 | // Can get and throw only unchecked exceptions |
| 288 | catch (RuntimeException e) { |
| 289 | processException(e, modalFiltersCount > 0); |
| 290 | } catch (Error e) { |
| 291 | processException(e, modalFiltersCount > 0); |
| 292 | } |
| 293 | return true; |
| 294 | } |
| 295 | |
| 296 | private void processException(Throwable e, boolean isModal) { |
| 297 | if (eventLog.isLoggable(Level.FINE)) { |
| 298 | eventLog.log(Level.FINE, "Processing exception: " + e + |
| 299 | ", isModal = " + isModal); |
| 300 | } |
| 301 | if (!handleException(e)) { |
| 302 | // See bug ID 4499199. |
| 303 | // If we are in a modal dialog, we cannot throw |
| 304 | // an exception for the ThreadGroup to handle (as added |
| 305 | // in RFE 4063022). If we did, the message pump of |
| 306 | // the modal dialog would be interrupted. |
| 307 | // We instead choose to handle the exception ourselves. |
| 308 | // It may be useful to add either a runtime flag or API |
| 309 | // later if someone would like to instead dispose the |
| 310 | // dialog and allow the thread group to handle it. |
| 311 | if (isModal) { |
| 312 | System.err.println( |
| 313 | "Exception occurred during event dispatching:"); |
| 314 | e.printStackTrace(); |
| 315 | } else if (e instanceof RuntimeException) { |
| 316 | throw (RuntimeException)e; |
| 317 | } else if (e instanceof Error) { |
| 318 | throw (Error)e; |
| 319 | } |
| 320 | } |
| 321 | } |
| 322 | |
| 323 | private static final String handlerPropName = "sun.awt.exception.handler"; |
| 324 | private static String handlerClassName = null; |
| 325 | private static String NO_HANDLER = new String(); |
| 326 | |
| 327 | /** |
| 328 | * Handles an exception thrown in the event-dispatch thread. |
| 329 | * |
| 330 | * <p> If the system property "sun.awt.exception.handler" is defined, then |
| 331 | * when this method is invoked it will attempt to do the following: |
| 332 | * |
| 333 | * <ol> |
| 334 | * <li> Load the class named by the value of that property, using the |
| 335 | * current thread's context class loader, |
| 336 | * <li> Instantiate that class using its zero-argument constructor, |
| 337 | * <li> Find the resulting handler object's <tt>public void handle</tt> |
| 338 | * method, which should take a single argument of type |
| 339 | * <tt>Throwable</tt>, and |
| 340 | * <li> Invoke the handler's <tt>handle</tt> method, passing it the |
| 341 | * <tt>thrown</tt> argument that was passed to this method. |
| 342 | * </ol> |
| 343 | * |
| 344 | * If any of the first three steps fail then this method will return |
| 345 | * <tt>false</tt> and all following invocations of this method will return |
| 346 | * <tt>false</tt> immediately. An exception thrown by the handler object's |
| 347 | * <tt>handle</tt> will be caught, and will cause this method to return |
| 348 | * <tt>false</tt>. If the handler's <tt>handle</tt> method is successfully |
| 349 | * invoked, then this method will return <tt>true</tt>. This method will |
| 350 | * never throw any sort of exception. |
| 351 | * |
| 352 | * <p> <i>Note:</i> This method is a temporary hack to work around the |
| 353 | * absence of a real API that provides the ability to replace the |
| 354 | * event-dispatch thread. The magic "sun.awt.exception.handler" property |
| 355 | * <i>will be removed</i> in a future release. |
| 356 | * |
| 357 | * @param thrown The Throwable that was thrown in the event-dispatch |
| 358 | * thread |
| 359 | * |
| 360 | * @return <tt>false</tt> if any of the above steps failed, otherwise |
| 361 | * <tt>true</tt> |
| 362 | */ |
| 363 | private boolean handleException(Throwable thrown) { |
| 364 | |
| 365 | try { |
| 366 | |
| 367 | if (handlerClassName == NO_HANDLER) { |
| 368 | return false; /* Already tried, and failed */ |
| 369 | } |
| 370 | |
| 371 | /* Look up the class name */ |
| 372 | if (handlerClassName == null) { |
| 373 | handlerClassName = ((String) AccessController.doPrivileged( |
| 374 | new GetPropertyAction(handlerPropName))); |
| 375 | if (handlerClassName == null) { |
| 376 | handlerClassName = NO_HANDLER; /* Do not try this again */ |
| 377 | return false; |
| 378 | } |
| 379 | } |
| 380 | |
| 381 | /* Load the class, instantiate it, and find its handle method */ |
| 382 | Method m; |
| 383 | Object h; |
| 384 | try { |
| 385 | ClassLoader cl = Thread.currentThread().getContextClassLoader(); |
| 386 | Class c = Class.forName(handlerClassName, true, cl); |
| 387 | m = c.getMethod("handle", new Class[] { Throwable.class }); |
| 388 | h = c.newInstance(); |
| 389 | } catch (Throwable x) { |
| 390 | handlerClassName = NO_HANDLER; /* Do not try this again */ |
| 391 | return false; |
| 392 | } |
| 393 | |
| 394 | /* Finally, invoke the handler */ |
| 395 | m.invoke(h, new Object[] { thrown }); |
| 396 | |
| 397 | } catch (Throwable x) { |
| 398 | return false; |
| 399 | } |
| 400 | |
| 401 | return true; |
| 402 | } |
| 403 | |
| 404 | boolean isDispatching(EventQueue eq) { |
| 405 | return theQueue.equals(eq); |
| 406 | } |
| 407 | |
| 408 | EventQueue getEventQueue() { return theQueue; } |
| 409 | |
| 410 | private static class HierarchyEventFilter implements EventFilter { |
| 411 | private Component modalComponent; |
| 412 | public HierarchyEventFilter(Component modalComponent) { |
| 413 | this.modalComponent = modalComponent; |
| 414 | } |
| 415 | public FilterAction acceptEvent(AWTEvent event) { |
| 416 | if (modalComponent != null) { |
| 417 | int eventID = event.getID(); |
| 418 | boolean mouseEvent = (eventID >= MouseEvent.MOUSE_FIRST) && |
| 419 | (eventID <= MouseEvent.MOUSE_LAST); |
| 420 | boolean actionEvent = (eventID >= ActionEvent.ACTION_FIRST) && |
| 421 | (eventID <= ActionEvent.ACTION_LAST); |
| 422 | boolean windowClosingEvent = (eventID == WindowEvent.WINDOW_CLOSING); |
| 423 | /* |
| 424 | * filter out MouseEvent and ActionEvent that's outside |
| 425 | * the modalComponent hierarchy. |
| 426 | * KeyEvent is handled by using enqueueKeyEvent |
| 427 | * in Dialog.show |
| 428 | */ |
| 429 | if (Component.isInstanceOf(modalComponent, "javax.swing.JInternalFrame")) { |
| 430 | /* |
| 431 | * Modal internal frames are handled separately. If event is |
| 432 | * for some component from another heavyweight than modalComp, |
| 433 | * it is accepted. If heavyweight is the same - we still accept |
| 434 | * event and perform further filtering in LightweightDispatcher |
| 435 | */ |
| 436 | return windowClosingEvent ? FilterAction.REJECT : FilterAction.ACCEPT; |
| 437 | } |
| 438 | if (mouseEvent || actionEvent || windowClosingEvent) { |
| 439 | Object o = event.getSource(); |
| 440 | if (o instanceof sun.awt.ModalExclude) { |
| 441 | // Exclude this object from modality and |
| 442 | // continue to pump it's events. |
| 443 | return FilterAction.ACCEPT; |
| 444 | } else if (o instanceof Component) { |
| 445 | Component c = (Component) o; |
| 446 | // 5.0u3 modal exclusion |
| 447 | boolean modalExcluded = false; |
| 448 | if (modalComponent instanceof Container) { |
| 449 | while (c != modalComponent && c != null) { |
| 450 | if ((c instanceof Window) && |
| 451 | (sun.awt.SunToolkit.isModalExcluded((Window)c))) { |
| 452 | // Exclude this window and all its children from |
| 453 | // modality and continue to pump it's events. |
| 454 | modalExcluded = true; |
| 455 | break; |
| 456 | } |
| 457 | c = c.getParent(); |
| 458 | } |
| 459 | } |
| 460 | if (!modalExcluded && (c != modalComponent)) { |
| 461 | return FilterAction.REJECT; |
| 462 | } |
| 463 | } |
| 464 | } |
| 465 | } |
| 466 | return FilterAction.ACCEPT; |
| 467 | } |
| 468 | } |
| 469 | } |