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 import sun.awt.AppContext;
  38 
  39 import java.util.ArrayList;
  40 import java.util.List;
  41 import sun.util.logging.PlatformLogger;
  42 
  43 import sun.awt.dnd.SunDragSourceContextPeer;
  44 import sun.awt.EventQueueDelegate;
  45 
  46 /**
  47  * EventDispatchThread is a package-private AWT class which takes
  48  * events off the EventQueue and dispatches them to the appropriate
  49  * AWT components.
  50  *
  51  * The Thread starts a "permanent" event pump with a call to
  52  * pumpEvents(Conditional) in its run() method. Event handlers can choose to
  53  * block this event pump at any time, but should start a new pump (<b>not</b>
  54  * a new EventDispatchThread) by again calling pumpEvents(Conditional). This
  55  * secondary event pump will exit automatically as soon as the Condtional
  56  * evaluate()s to false and an additional Event is pumped and dispatched.
  57  *
  58  * @author Tom Ball
  59  * @author Amy Fowler
  60  * @author Fred Ecks
  61  * @author David Mendenhall
  62  *
  63  * @since 1.1
  64  */
  65 class EventDispatchThread extends Thread {
  66 
  67     private static final PlatformLogger eventLog = PlatformLogger.getLogger("java.awt.event.EventDispatchThread");
  68 
  69     private EventQueue theQueue;
  70     private boolean doDispatch = true;
  71     private volatile boolean shutdown = false;
  72 
  73     private static final int ANY_EVENT = -1;
  74 
  75     private ArrayList<EventFilter> eventFilters = new ArrayList<EventFilter>();
  76 
  77     EventDispatchThread(ThreadGroup group, String name, EventQueue queue) {
  78         super(group, name);
  79         setEventQueue(queue);
  80     }
  81 
  82     /*
  83      * Must be called on EDT only, that's why no synchronization
  84      */
  85     public void stopDispatching() {
  86         doDispatch = false;
  87     }
  88 
  89     public void interrupt() {
  90         shutdown = true;
  91         super.interrupt();
  92     }
  93 
  94     public void run() {
  95         while (true) {
  96             try {
  97                 pumpEvents(new Conditional() {
  98                     public boolean evaluate() {
  99                         return true;
 100                     }
 101                 });
 102             } finally {
 103                 if(getEventQueue().detachDispatchThread(this, shutdown)) {
 104                     break;
 105                 }
 106             }
 107         }
 108     }
 109 
 110     void pumpEvents(Conditional cond) {
 111         pumpEvents(ANY_EVENT, cond);
 112     }
 113 
 114     void pumpEventsForHierarchy(Conditional cond, Component modalComponent) {
 115         pumpEventsForHierarchy(ANY_EVENT, cond, modalComponent);
 116     }
 117 
 118     void pumpEvents(int id, Conditional cond) {
 119         pumpEventsForHierarchy(id, cond, null);
 120     }
 121 
 122     void pumpEventsForHierarchy(int id, Conditional cond, Component modalComponent) {
 123         pumpEventsForFilter(id, cond, new HierarchyEventFilter(modalComponent));
 124     }
 125 
 126     void pumpEventsForFilter(Conditional cond, EventFilter filter) {
 127         pumpEventsForFilter(ANY_EVENT, cond, filter);
 128     }
 129 
 130     void pumpEventsForFilter(int id, Conditional cond, EventFilter filter) {
 131         addEventFilter(filter);
 132         doDispatch = true;
 133         shutdown |= isInterrupted();
 134         while (doDispatch && !shutdown && cond.evaluate()) {
 135             pumpOneEventForFilters(id);
 136         }
 137         removeEventFilter(filter);
 138     }
 139 
 140     void addEventFilter(EventFilter filter) {
 141         if (eventLog.isLoggable(PlatformLogger.FINEST)) {
 142             eventLog.finest("adding the event filter: " + filter);
 143         }
 144         synchronized (eventFilters) {
 145             if (!eventFilters.contains(filter)) {
 146                 if (filter instanceof ModalEventFilter) {
 147                     ModalEventFilter newFilter = (ModalEventFilter)filter;
 148                     int k = 0;
 149                     for (k = 0; k < eventFilters.size(); k++) {
 150                         EventFilter f = eventFilters.get(k);
 151                         if (f instanceof ModalEventFilter) {
 152                             ModalEventFilter cf = (ModalEventFilter)f;
 153                             if (cf.compareTo(newFilter) > 0) {
 154                                 break;
 155                             }
 156                         }
 157                     }
 158                     eventFilters.add(k, filter);
 159                 } else {
 160                     eventFilters.add(filter);
 161                 }
 162             }
 163         }
 164     }
 165 
 166     void removeEventFilter(EventFilter filter) {
 167         if (eventLog.isLoggable(PlatformLogger.FINEST)) {
 168             eventLog.finest("removing the event filter: " + filter);
 169         }
 170         synchronized (eventFilters) {
 171             eventFilters.remove(filter);
 172         }
 173     }
 174 
 175     void pumpOneEventForFilters(int id) {
 176         AWTEvent event = null;
 177         boolean eventOK = false;
 178         try {
 179             EventQueue eq = null;
 180             EventQueueDelegate.Delegate delegate = null;
 181             do {
 182                 // EventQueue may change during the dispatching
 183                 eq = getEventQueue();
 184                 delegate = EventQueueDelegate.getDelegate();
 185 
 186                 if (delegate != null && id == ANY_EVENT) {
 187                     event = delegate.getNextEvent(eq);
 188                 } else {
 189                     event = (id == ANY_EVENT) ? eq.getNextEvent() : eq.getNextEvent(id);
 190                 }
 191 
 192                 eventOK = true;
 193                 synchronized (eventFilters) {
 194                     for (int i = eventFilters.size() - 1; i >= 0; i--) {
 195                         EventFilter f = eventFilters.get(i);
 196                         EventFilter.FilterAction accept = f.acceptEvent(event);
 197                         if (accept == EventFilter.FilterAction.REJECT) {
 198                             eventOK = false;
 199                             break;
 200                         } else if (accept == EventFilter.FilterAction.ACCEPT_IMMEDIATELY) {
 201                             break;
 202                         }
 203                     }
 204                 }
 205                 eventOK = eventOK && SunDragSourceContextPeer.checkEvent(event);
 206                 if (!eventOK) {
 207                     event.consume();
 208                 }
 209             }
 210             while (eventOK == false);
 211 
 212             if (eventLog.isLoggable(PlatformLogger.FINEST)) {
 213                 eventLog.finest("Dispatching: " + event);
 214             }
 215 
 216             Object handle = null;
 217             if (delegate != null) {
 218                 handle = delegate.beforeDispatch(event);
 219             }
 220             eq.dispatchEvent(event);
 221             if (delegate != null) {
 222                 delegate.afterDispatch(event, handle);
 223             }
 224         }
 225         catch (ThreadDeath death) {
 226             shutdown = true;
 227             throw death;
 228         }
 229         catch (InterruptedException interruptedException) {
 230             shutdown = true; // AppContext.dispose() interrupts all
 231                              // Threads in the AppContext
 232         }
 233         catch (Throwable e) {
 234             processException(e);
 235         }
 236     }
 237 
 238     private void processException(Throwable e) {
 239         if (eventLog.isLoggable(PlatformLogger.FINE)) {
 240             eventLog.fine("Processing exception: " + e);
 241         }
 242         getUncaughtExceptionHandler().uncaughtException(this, e);
 243     }
 244 
 245     public synchronized EventQueue getEventQueue() {
 246         return theQueue;
 247     }
 248     public synchronized void setEventQueue(EventQueue eq) {
 249         theQueue = eq;
 250     }
 251 
 252     private static class HierarchyEventFilter implements EventFilter {
 253         private Component modalComponent;
 254         public HierarchyEventFilter(Component modalComponent) {
 255             this.modalComponent = modalComponent;
 256         }
 257         public FilterAction acceptEvent(AWTEvent event) {
 258             if (modalComponent != null) {
 259                 int eventID = event.getID();
 260                 boolean mouseEvent = (eventID >= MouseEvent.MOUSE_FIRST) &&
 261                                      (eventID <= MouseEvent.MOUSE_LAST);
 262                 boolean actionEvent = (eventID >= ActionEvent.ACTION_FIRST) &&
 263                                       (eventID <= ActionEvent.ACTION_LAST);
 264                 boolean windowClosingEvent = (eventID == WindowEvent.WINDOW_CLOSING);
 265                 /*
 266                  * filter out MouseEvent and ActionEvent that's outside
 267                  * the modalComponent hierarchy.
 268                  * KeyEvent is handled by using enqueueKeyEvent
 269                  * in Dialog.show
 270                  */
 271                 if (Component.isInstanceOf(modalComponent, "javax.swing.JInternalFrame")) {
 272                     /*
 273                      * Modal internal frames are handled separately. If event is
 274                      * for some component from another heavyweight than modalComp,
 275                      * it is accepted. If heavyweight is the same - we still accept
 276                      * event and perform further filtering in LightweightDispatcher
 277                      */
 278                     return windowClosingEvent ? FilterAction.REJECT : FilterAction.ACCEPT;
 279                 }
 280                 if (mouseEvent || actionEvent || windowClosingEvent) {
 281                     Object o = event.getSource();
 282                     if (o instanceof sun.awt.ModalExclude) {
 283                         // Exclude this object from modality and
 284                         // continue to pump it's events.
 285                         return FilterAction.ACCEPT;
 286                     } else if (o instanceof Component) {
 287                         Component c = (Component) o;
 288                         // 5.0u3 modal exclusion
 289                         boolean modalExcluded = false;
 290                         if (modalComponent instanceof Container) {
 291                             while (c != modalComponent && c != null) {
 292                                 if ((c instanceof Window) &&
 293                                     (sun.awt.SunToolkit.isModalExcluded((Window)c))) {
 294                                     // Exclude this window and all its children from
 295                                     //  modality and continue to pump it's events.
 296                                     modalExcluded = true;
 297                                     break;
 298                                 }
 299                                 c = c.getParent();
 300                             }
 301                         }
 302                         if (!modalExcluded && (c != modalComponent)) {
 303                             return FilterAction.REJECT;
 304                         }
 305                     }
 306                 }
 307             }
 308             return FilterAction.ACCEPT;
 309         }
 310     }
 311 }