1 /*
   2  * Copyright (c) 1996, 2010, 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.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 sun.util.logging.PlatformLogger;
  40 
  41 import sun.awt.dnd.SunDragSourceContextPeer;
  42 import sun.awt.EventQueueDelegate;
  43 
  44 /**
  45  * EventDispatchThread is a package-private AWT class which takes
  46  * events off the EventQueue and dispatches them to the appropriate
  47  * AWT components.
  48  *
  49  * The Thread starts a "permanent" event pump with a call to
  50  * pumpEvents(Conditional) in its run() method. Event handlers can choose to
  51  * block this event pump at any time, but should start a new pump (<b>not</b>
  52  * a new EventDispatchThread) by again calling pumpEvents(Conditional). This
  53  * secondary event pump will exit automatically as soon as the Condtional
  54  * evaluate()s to false and an additional Event is pumped and dispatched.
  55  *
  56  * @author Tom Ball
  57  * @author Amy Fowler
  58  * @author Fred Ecks
  59  * @author David Mendenhall
  60  *
  61  * @since 1.1
  62  */
  63 class EventDispatchThread extends Thread {
  64 
  65     private static final PlatformLogger eventLog = PlatformLogger.getLogger("java.awt.event.EventDispatchThread");
  66 
  67     private EventQueue theQueue;
  68     private boolean doDispatch = true;
  69     private boolean threadDeathCaught = false;
  70 
  71     private static final int ANY_EVENT = -1;
  72 
  73     private Vector<EventFilter> eventFilters = new Vector<EventFilter>();
  74 
  75     EventDispatchThread(ThreadGroup group, String name, EventQueue queue) {
  76         super(group, name);
  77         setEventQueue(queue);
  78     }
  79 
  80     /*
  81      * Must be called on EDT only, that's why no synchronization
  82      */
  83     public void stopDispatching() {
  84         doDispatch = false;
  85     }
  86 
  87     public void run() {
  88         while (true) {
  89             try {
  90                 pumpEvents(new Conditional() {
  91                     public boolean evaluate() {
  92                         return true;
  93                     }
  94                 });
  95             } finally {
  96                 EventQueue eq = getEventQueue();
  97                 if (eq.detachDispatchThread(this) || threadDeathCaught) {
  98                     break;
  99                 }
 100             }
 101         }
 102     }
 103 
 104     void pumpEvents(Conditional cond) {
 105         pumpEvents(ANY_EVENT, cond);
 106     }
 107 
 108     void pumpEventsForHierarchy(Conditional cond, Component modalComponent) {
 109         pumpEventsForHierarchy(ANY_EVENT, cond, modalComponent);
 110     }
 111 
 112     void pumpEvents(int id, Conditional cond) {
 113         pumpEventsForHierarchy(id, cond, null);
 114     }
 115 
 116     void pumpEventsForHierarchy(int id, Conditional cond, Component modalComponent) {
 117         pumpEventsForFilter(id, cond, new HierarchyEventFilter(modalComponent));
 118     }
 119 
 120     void pumpEventsForFilter(Conditional cond, EventFilter filter) {
 121         pumpEventsForFilter(ANY_EVENT, cond, filter);
 122     }
 123 
 124     void pumpEventsForFilter(int id, Conditional cond, EventFilter filter) {
 125         addEventFilter(filter);
 126         doDispatch = true;
 127         while (doDispatch && cond.evaluate()) {
 128             if (isInterrupted() || !pumpOneEventForFilters(id)) {
 129                 doDispatch = false;
 130             }
 131         }
 132         removeEventFilter(filter);
 133     }
 134 
 135     void addEventFilter(EventFilter filter) {
 136         eventLog.finest("adding the event filter: " + filter);
 137         synchronized (eventFilters) {
 138             if (!eventFilters.contains(filter)) {
 139                 if (filter instanceof ModalEventFilter) {
 140                     ModalEventFilter newFilter = (ModalEventFilter)filter;
 141                     int k = 0;
 142                     for (k = 0; k < eventFilters.size(); k++) {
 143                         EventFilter f = eventFilters.get(k);
 144                         if (f instanceof ModalEventFilter) {
 145                             ModalEventFilter cf = (ModalEventFilter)f;
 146                             if (cf.compareTo(newFilter) > 0) {
 147                                 break;
 148                             }
 149                         }
 150                     }
 151                     eventFilters.add(k, filter);
 152                 } else {
 153                     eventFilters.add(filter);
 154                 }
 155             }
 156         }
 157     }
 158 
 159     void removeEventFilter(EventFilter filter) {
 160         eventLog.finest("removing the event filter: " + filter);
 161         synchronized (eventFilters) {
 162             eventFilters.remove(filter);
 163         }
 164     }
 165 
 166     boolean pumpOneEventForFilters(int id) {
 167         AWTEvent event = null;
 168         boolean eventOK = false;
 169         try {
 170             EventQueue eq = null;
 171             EventQueueDelegate.Delegate delegate = null;
 172             do {
 173                 // EventQueue may change during the dispatching
 174                 eq = getEventQueue();
 175                 delegate = EventQueueDelegate.getDelegate();
 176 
 177                 if (delegate != null && id == ANY_EVENT) {
 178                     event = delegate.getNextEvent(eq);
 179                 } else {
 180                     event = (id == ANY_EVENT) ? eq.getNextEvent() : eq.getNextEvent(id);
 181                 }
 182 
 183                 eventOK = true;
 184                 synchronized (eventFilters) {
 185                     for (int i = eventFilters.size() - 1; i >= 0; i--) {
 186                         EventFilter f = eventFilters.get(i);
 187                         EventFilter.FilterAction accept = f.acceptEvent(event);
 188                         if (accept == EventFilter.FilterAction.REJECT) {
 189                             eventOK = false;
 190                             break;
 191                         } else if (accept == EventFilter.FilterAction.ACCEPT_IMMEDIATELY) {
 192                             break;
 193                         }
 194                     }
 195                 }
 196                 eventOK = eventOK && SunDragSourceContextPeer.checkEvent(event);
 197                 if (!eventOK) {
 198                     event.consume();
 199                 }
 200             }
 201             while (eventOK == false);
 202 
 203             if (eventLog.isLoggable(PlatformLogger.FINEST)) {
 204                 eventLog.finest("Dispatching: " + event);
 205             }
 206 
 207             Object handle = null;
 208             if (delegate != null) {
 209                 handle = delegate.beforeDispatch(event);
 210             }
 211             eq.dispatchEvent(event);
 212             if (delegate != null) {
 213                 delegate.afterDispatch(event, handle);
 214             }
 215 
 216             return true;
 217         }
 218         catch (ThreadDeath death) {
 219             threadDeathCaught = true;
 220             return false;
 221 
 222         }
 223         catch (InterruptedException interruptedException) {
 224             return false; // AppContext.dispose() interrupts all
 225                           // Threads in the AppContext
 226 
 227         }
 228         catch (Throwable e) {
 229             processException(e);
 230         }
 231 
 232         return true;
 233     }
 234 
 235     private void processException(Throwable e) {
 236         if (eventLog.isLoggable(PlatformLogger.FINE)) {
 237             eventLog.fine("Processing exception: " + e);
 238         }
 239         getUncaughtExceptionHandler().uncaughtException(this, e);
 240     }
 241 
 242     public synchronized EventQueue getEventQueue() {
 243         return theQueue;
 244     }
 245     public synchronized void setEventQueue(EventQueue eq) {
 246         theQueue = eq;
 247     }
 248 
 249     private static class HierarchyEventFilter implements EventFilter {
 250         private Component modalComponent;
 251         public HierarchyEventFilter(Component modalComponent) {
 252             this.modalComponent = modalComponent;
 253         }
 254         public FilterAction acceptEvent(AWTEvent event) {
 255             if (modalComponent != null) {
 256                 int eventID = event.getID();
 257                 boolean mouseEvent = (eventID >= MouseEvent.MOUSE_FIRST) &&
 258                                      (eventID <= MouseEvent.MOUSE_LAST);
 259                 boolean actionEvent = (eventID >= ActionEvent.ACTION_FIRST) &&
 260                                       (eventID <= ActionEvent.ACTION_LAST);
 261                 boolean windowClosingEvent = (eventID == WindowEvent.WINDOW_CLOSING);
 262                 /*
 263                  * filter out MouseEvent and ActionEvent that's outside
 264                  * the modalComponent hierarchy.
 265                  * KeyEvent is handled by using enqueueKeyEvent
 266                  * in Dialog.show
 267                  */
 268                 if (Component.isInstanceOf(modalComponent, "javax.swing.JInternalFrame")) {
 269                     /*
 270                      * Modal internal frames are handled separately. If event is
 271                      * for some component from another heavyweight than modalComp,
 272                      * it is accepted. If heavyweight is the same - we still accept
 273                      * event and perform further filtering in LightweightDispatcher
 274                      */
 275                     return windowClosingEvent ? FilterAction.REJECT : FilterAction.ACCEPT;
 276                 }
 277                 if (mouseEvent || actionEvent || windowClosingEvent) {
 278                     Object o = event.getSource();
 279                     if (o instanceof sun.awt.ModalExclude) {
 280                         // Exclude this object from modality and
 281                         // continue to pump it's events.
 282                         return FilterAction.ACCEPT;
 283                     } else if (o instanceof Component) {
 284                         Component c = (Component) o;
 285                         // 5.0u3 modal exclusion
 286                         boolean modalExcluded = false;
 287                         if (modalComponent instanceof Container) {
 288                             while (c != modalComponent && c != null) {
 289                                 if ((c instanceof Window) &&
 290                                     (sun.awt.SunToolkit.isModalExcluded((Window)c))) {
 291                                     // Exclude this window and all its children from
 292                                     //  modality and continue to pump it's events.
 293                                     modalExcluded = true;
 294                                     break;
 295                                 }
 296                                 c = c.getParent();
 297                             }
 298                         }
 299                         if (!modalExcluded && (c != modalComponent)) {
 300                             return FilterAction.REJECT;
 301                         }
 302                     }
 303                 }
 304             }
 305             return FilterAction.ACCEPT;
 306         }
 307     }
 308 }