/*

 * Copyright 1996-2008 Sun Microsystems, Inc.  All Rights Reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package java.awt;

import java.awt.event.InputEvent;

import java.awt.event.MouseEvent;

import java.awt.event.ActionEvent;

import java.awt.event.WindowEvent;

import java.lang.reflect.Method;

import java.security.AccessController;

import sun.security.action.GetPropertyAction;

import sun.awt.AWTAutoShutdown;

import sun.awt.SunToolkit;

import java.util.Vector;

import sun.util.logging.PlatformLogger;

import sun.awt.dnd.SunDragSourceContextPeer;

import sun.awt.EventQueueDelegate;

/**

 * EventDispatchThread is a package-private AWT class which takes

 * events off the EventQueue and dispatches them to the appropriate

 * AWT components.

 *

 * The Thread starts a "permanent" event pump with a call to

 * pumpEvents(Conditional) in its run() method. Event handlers can choose to

 * block this event pump at any time, but should start a new pump (<b>not</b>

 * a new EventDispatchThread) by again calling pumpEvents(Conditional). This

 * secondary event pump will exit automatically as soon as the Condtional

 * evaluate()s to false and an additional Event is pumped and dispatched.

 *

 * @author Tom Ball

 * @author Amy Fowler

 * @author Fred Ecks

 * @author David Mendenhall

 *

 * @since 1.1

 */

class EventDispatchThread extends Thread {

    private static final PlatformLogger eventLog = PlatformLogger.getLogger("java.awt.event.EventDispatchThread");

    private EventQueue theQueue;

    private boolean doDispatch = true;

    private static final int ANY_EVENT = -1;

    private Vector<EventFilter> eventFilters = new Vector<EventFilter>();

    // used in handleException

    private int modalFiltersCount = 0;

    EventDispatchThread(ThreadGroup group, String name, EventQueue queue) {

        super(group, name);

        theQueue = queue;

    }

    void stopDispatchingImpl(boolean wait) {

        // Note: We stop dispatching via a flag rather than using

        // Thread.interrupt() because we can't guarantee that the wait()

        // we interrupt will be EventQueue.getNextEvent()'s.  -fredx 8-11-98

        StopDispatchEvent stopEvent = new StopDispatchEvent();

        // wait for the dispatcher to complete

        if (Thread.currentThread() != this) {

            // fix 4122683, 4128923

            // Post an empty event to ensure getNextEvent is unblocked

            //

            // We have to use postEventPrivate instead of postEvent because

            // EventQueue.pop calls EventDispatchThread.stopDispatching.

            // Calling SunToolkit.flushPendingEvents in this case could

            // lead to deadlock.

            theQueue.postEventPrivate(stopEvent);

            if (wait) {

                try {

                    join();

                } catch(InterruptedException e) {

                }

            }

        } else {

            stopEvent.dispatch();

        }

        theQueue.detachDispatchThread(this, false);

    }

    public void stopDispatching() {

        stopDispatchingImpl(true);

    }

    public void stopDispatchingLater() {

        stopDispatchingImpl(false);

    }

    class StopDispatchEvent extends AWTEvent implements ActiveEvent {

        /*

         * serialVersionUID

         */

        static final long serialVersionUID = -3692158172100730735L;

        public StopDispatchEvent() {

            super(EventDispatchThread.this,0);

        }

        public void dispatch() {

            doDispatch = false;

        }

    }

    public void run() {

        try {

            pumpEvents(new Conditional() {

                public boolean evaluate() {

                    return true;

                }

            });

        } finally {

            theQueue.detachDispatchThread(this, true);

        }

    }

    void pumpEvents(Conditional cond) {

        pumpEvents(ANY_EVENT, cond);

    }

    void pumpEventsForHierarchy(Conditional cond, Component modalComponent) {

        pumpEventsForHierarchy(ANY_EVENT, cond, modalComponent);

    }

    void pumpEvents(int id, Conditional cond) {

        pumpEventsForHierarchy(id, cond, null);

    }

    void pumpEventsForHierarchy(int id, Conditional cond, Component modalComponent)

    {

        pumpEventsForFilter(id, cond, new HierarchyEventFilter(modalComponent));

    }

    void pumpEventsForFilter(Conditional cond, EventFilter filter) {

        pumpEventsForFilter(ANY_EVENT, cond, filter);

    }

    void pumpEventsForFilter(int id, Conditional cond, EventFilter filter) {

        addEventFilter(filter);

        while (doDispatch && cond.evaluate()) {

            if (isInterrupted() || !pumpOneEventForFilters(id)) {

                doDispatch = false;

            }

        }

        removeEventFilter(filter);

    }

    void addEventFilter(EventFilter filter) {

        synchronized (eventFilters) {

            if (!eventFilters.contains(filter)) {

                if (filter instanceof ModalEventFilter) {

                    ModalEventFilter newFilter = (ModalEventFilter)filter;

                    int k = 0;

                    for (k = 0; k < eventFilters.size(); k++) {

                        EventFilter f = eventFilters.get(k);

                        if (f instanceof ModalEventFilter) {

                            ModalEventFilter cf = (ModalEventFilter)f;

                            if (cf.compareTo(newFilter) > 0) {

                                break;

                            }

                        }

                    }

                    eventFilters.add(k, filter);

                    modalFiltersCount++;

                } else {

                    eventFilters.add(filter);

                }

            }

        }

    }

    void removeEventFilter(EventFilter filter) {

        synchronized (eventFilters) {

            if (eventFilters.contains(filter)) {

                if (filter instanceof ModalEventFilter) {

                    modalFiltersCount--;

                }

                eventFilters.remove(filter);

            }

        }

    }

    boolean pumpOneEventForFilters(int id) {

        try {

            AWTEvent event;

            boolean eventOK;

            EventQueueDelegate.Delegate delegate =

                EventQueueDelegate.getDelegate();

            do {

                if (delegate != null && id == ANY_EVENT) {

                    event = delegate.getNextEvent(theQueue);

                } else {

                    event = (id == ANY_EVENT)

                        ? theQueue.getNextEvent()

                        : theQueue.getNextEvent(id);

                }

                eventOK = true;

                synchronized (eventFilters) {

                    for (int i = eventFilters.size() - 1; i >= 0; i--) {

                        EventFilter f = eventFilters.get(i);

                        EventFilter.FilterAction accept = f.acceptEvent(event);

                        if (accept == EventFilter.FilterAction.REJECT) {

                            eventOK = false;

                            break;

                        } else if (accept == EventFilter.FilterAction.ACCEPT_IMMEDIATELY) {

                            break;

                        }

                    }

                }

                eventOK = eventOK && SunDragSourceContextPeer.checkEvent(event);

                if (!eventOK) {

                    event.consume();

                }

            }

            while (eventOK == false);

            if (eventLog.isLoggable(PlatformLogger.FINEST)) {

                eventLog.finest("Dispatching: " + event);

            }

            Object handle = null;

            if (delegate != null) {

                handle = delegate.beforeDispatch(event);

            }

            theQueue.dispatchEvent(event);

            if (delegate != null) {

                delegate.afterDispatch(event, handle);

            }

            return true;

        }

        catch (ThreadDeath death) {

            return false;

        }

        catch (InterruptedException interruptedException) {

            return false; // AppContext.dispose() interrupts all

                          // Threads in the AppContext

        }

        // Can get and throw only unchecked exceptions

        catch (RuntimeException e) {

            processException(e);

        } catch (Error e) {

            processException(e);

        }

        return true;

    }

    private void processException(Throwable e) {

        if (eventLog.isLoggable(PlatformLogger.FINE)) {

            eventLog.fine("Processing exception: " + e);

        }

        getUncaughtExceptionHandler().uncaughtException(this, e);

        // don't rethrow the exception to avoid EDT recreation

    }

    boolean isDispatching(EventQueue eq) {

        return theQueue.equals(eq);

    }

    EventQueue getEventQueue() { return theQueue; }

    private static class HierarchyEventFilter implements EventFilter {

        private Component modalComponent;

        public HierarchyEventFilter(Component modalComponent) {

            this.modalComponent = modalComponent;

        }

        public FilterAction acceptEvent(AWTEvent event) {

            if (modalComponent != null) {

                int eventID = event.getID();

                boolean mouseEvent = (eventID >= MouseEvent.MOUSE_FIRST) &&

                                     (eventID <= MouseEvent.MOUSE_LAST);

                boolean actionEvent = (eventID >= ActionEvent.ACTION_FIRST) &&

                                      (eventID <= ActionEvent.ACTION_LAST);

                boolean windowClosingEvent = (eventID == WindowEvent.WINDOW_CLOSING);

                /*

                 * filter out MouseEvent and ActionEvent that's outside

                 * the modalComponent hierarchy.

                 * KeyEvent is handled by using enqueueKeyEvent

                 * in Dialog.show

                 */

                if (Component.isInstanceOf(modalComponent, "javax.swing.JInternalFrame")) {

                    /*

                     * Modal internal frames are handled separately. If event is

                     * for some component from another heavyweight than modalComp,

                     * it is accepted. If heavyweight is the same - we still accept

                     * event and perform further filtering in LightweightDispatcher

                     */

                    return windowClosingEvent ? FilterAction.REJECT : FilterAction.ACCEPT;

                }

                if (mouseEvent || actionEvent || windowClosingEvent) {

                    Object o = event.getSource();

                    if (o instanceof sun.awt.ModalExclude) {

                        // Exclude this object from modality and

                        // continue to pump it's events.

                        return FilterAction.ACCEPT;

                    } else if (o instanceof Component) {

                        Component c = (Component) o;

                        // 5.0u3 modal exclusion

                        boolean modalExcluded = false;

                        if (modalComponent instanceof Container) {

                            while (c != modalComponent && c != null) {

                                if ((c instanceof Window) &&

                                    (sun.awt.SunToolkit.isModalExcluded((Window)c))) {

                                    // Exclude this window and all its children from

                                    //  modality and continue to pump it's events.

                                    modalExcluded = true;

                                    break;

                                }

                                c = c.getParent();

                            }

                        }

                        if (!modalExcluded && (c != modalComponent)) {

                            return FilterAction.REJECT;

                        }

                    }

                }

            }

            return FilterAction.ACCEPT;

        }

    }

}