/****************************************************************************
**
** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the QtGui module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Digia.  For licensing terms and
** conditions see http://qt.digia.com/licensing.  For further information
** use the contact form at http://qt.digia.com/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Digia gives you certain additional
** rights.  These rights are described in the Digia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
**
** $QT_END_LICENSE$
**
****************************************************************************/

/****************************************************************************
**
** Copyright (c) 2007-2008, Apple, Inc.
**
** All rights reserved.
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are met:
**
**   * Redistributions of source code must retain the above copyright notice,
**     this list of conditions and the following disclaimer.
**
**   * Redistributions in binary form must reproduce the above copyright notice,
**     this list of conditions and the following disclaimer in the documentation
**     and/or other materials provided with the distribution.
**
**   * Neither the name of Apple, Inc. nor the names of its contributors
**     may be used to endorse or promote products derived from this software
**     without specific prior written permission.
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
** CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
** EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
** PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
** PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
** LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
** NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
** SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
**
****************************************************************************/

#include "qplatformdefs.h"
#include "private/qt_mac_p.h"
#include "qeventdispatcher_mac_p.h"
#include "qapplication.h"
#include "qevent.h"
#include "qdialog.h"
#include "qhash.h"
#include "qsocketnotifier.h"
#include "private/qwidget_p.h"
#include "private/qthread_p.h"
#include "private/qapplication_p.h"

#include <private/qcocoaapplication_mac_p.h>
#include "private/qt_cocoa_helpers_mac_p.h"

#ifndef QT_NO_THREAD
#  include "qmutex.h"
#endif

QT_BEGIN_NAMESPACE

QT_USE_NAMESPACE

/*****************************************************************************
  Externals
 *****************************************************************************/
extern void qt_event_request_timer(MacTimerInfo *); //qapplication_mac.cpp
extern MacTimerInfo *qt_event_get_timer(EventRef); //qapplication_mac.cpp
extern void qt_event_request_select(QEventDispatcherMac *); //qapplication_mac.cpp
extern void qt_event_request_updates(); //qapplication_mac.cpp
extern OSWindowRef qt_mac_window_for(const QWidget *); //qwidget_mac.cpp
extern bool qt_is_gui_used; //qapplication.cpp
extern bool qt_sendSpontaneousEvent(QObject*, QEvent*); // qapplication.cpp
extern bool qt_mac_is_macsheet(const QWidget *); //qwidget_mac.cpp

static inline CFRunLoopRef mainRunLoop()
{
#ifndef QT_MAC_USE_COCOA
    return reinterpret_cast<CFRunLoopRef>(const_cast<void *>(GetCFRunLoopFromEventLoop(GetMainEventLoop())));
#else
    return CFRunLoopGetMain();
#endif
}

/*****************************************************************************
  Timers stuff
 *****************************************************************************/

/* timer call back */
void QEventDispatcherMacPrivate::activateTimer(CFRunLoopTimerRef, void *info)
{
    int timerID =
#ifdef Q_OS_MAC64
    qint64(info);
#else
    int(info);
#endif

    MacTimerInfo *tmr;
    tmr = macTimerHash.value(timerID);
    if (tmr == 0 || tmr->pending == true)
        return; // Can't send another timer event if it's pending.


    if (blockSendPostedEvents) {
        QCoreApplication::postEvent(tmr->obj, new QTimerEvent(tmr->id));
    } else {
        tmr->pending = true;
        QTimerEvent e(tmr->id);
        qt_sendSpontaneousEvent(tmr->obj, &e);
        // Get the value again in case the timer gets unregistered during the sendEvent.
        tmr = macTimerHash.value(timerID);
        if (tmr != 0)
            tmr->pending = false;
    }

}

void QEventDispatcherMac::registerTimer(int timerId, int interval, QObject *obj)
{
#ifndef QT_NO_DEBUG
    if (timerId < 1 || interval < 0 || !obj) {
        qWarning("QEventDispatcherMac::registerTimer: invalid arguments");
        return;
    } else if (obj->thread() != thread() || thread() != QThread::currentThread()) {
        qWarning("QObject::startTimer: timers cannot be started from another thread");
        return;
    }
#endif

    MacTimerInfo *t = new MacTimerInfo();
    t->id = timerId;
    t->interval = interval;
    t->obj = obj;
    t->runLoopTimer = 0;
    t->pending = false;

    CFAbsoluteTime fireDate = CFAbsoluteTimeGetCurrent();
    CFTimeInterval cfinterval = qMax(CFTimeInterval(interval) / 1000, 0.0000001);
    fireDate += cfinterval;
    QEventDispatcherMacPrivate::macTimerHash.insert(timerId, t);
    CFRunLoopTimerContext info = { 0, (void *)timerId, 0, 0, 0 };
    t->runLoopTimer = CFRunLoopTimerCreate(0, fireDate, cfinterval, 0, 0,
                                           QEventDispatcherMacPrivate::activateTimer, &info);
    if (t->runLoopTimer == 0) {
        qFatal("QEventDispatcherMac::registerTimer: Cannot create timer");
    }
    CFRunLoopAddTimer(mainRunLoop(), t->runLoopTimer, kCFRunLoopCommonModes);
}

bool QEventDispatcherMac::unregisterTimer(int identifier)
{
#ifndef QT_NO_DEBUG
    if (identifier < 1) {
        qWarning("QEventDispatcherMac::unregisterTimer: invalid argument");
        return false;
    } else if (thread() != QThread::currentThread()) {
        qWarning("QObject::killTimer: timers cannot be stopped from another thread");
        return false;
    }
#endif
    if (identifier <= 0)
        return false;                                // not init'd or invalid timer

    MacTimerInfo *timerInfo = QEventDispatcherMacPrivate::macTimerHash.take(identifier);
    if (timerInfo == 0)
        return false;

    if (!QObjectPrivate::get(timerInfo->obj)->inThreadChangeEvent)
        QAbstractEventDispatcherPrivate::releaseTimerId(identifier);
    CFRunLoopTimerInvalidate(timerInfo->runLoopTimer);
    CFRelease(timerInfo->runLoopTimer);
    delete timerInfo;

    return true;
}

bool QEventDispatcherMac::unregisterTimers(QObject *obj)
{
#ifndef QT_NO_DEBUG
    if (!obj) {
        qWarning("QEventDispatcherMac::unregisterTimers: invalid argument");
        return false;
    } else if (obj->thread() != thread() || thread() != QThread::currentThread()) {
        qWarning("QObject::killTimers: timers cannot be stopped from another thread");
        return false;
    }
#endif

    MacTimerHash::iterator it = QEventDispatcherMacPrivate::macTimerHash.begin();
    while (it != QEventDispatcherMacPrivate::macTimerHash.end()) {
        MacTimerInfo *timerInfo = it.value();
        if (timerInfo->obj != obj) {
            ++it;
        } else {
            if (!QObjectPrivate::get(timerInfo->obj)->inThreadChangeEvent)
                QAbstractEventDispatcherPrivate::releaseTimerId(timerInfo->id);
            CFRunLoopTimerInvalidate(timerInfo->runLoopTimer);
            CFRelease(timerInfo->runLoopTimer);
            delete timerInfo;
            it = QEventDispatcherMacPrivate::macTimerHash.erase(it);
        }
    }
    return true;
}

QList<QEventDispatcherMac::TimerInfo>
QEventDispatcherMac::registeredTimers(QObject *object) const
{
    if (!object) {
        qWarning("QEventDispatcherMac:registeredTimers: invalid argument");
        return QList<TimerInfo>();
    }

    QList<TimerInfo> list;

    MacTimerHash::const_iterator it = QEventDispatcherMacPrivate::macTimerHash.constBegin();
    while (it != QEventDispatcherMacPrivate::macTimerHash.constEnd()) {
        MacTimerInfo *t = it.value();
        if (t->obj == object)
            list << TimerInfo(t->id, t->interval);
        ++it;
    }
    return list;
}

/**************************************************************************
    Socket Notifiers
 *************************************************************************/
void qt_mac_socket_callback(CFSocketRef s, CFSocketCallBackType callbackType, CFDataRef,
                            const void *,  void *info) {
    QEventDispatcherMacPrivate *const eventDispatcher
                                    = static_cast<QEventDispatcherMacPrivate *>(info);
    int nativeSocket = CFSocketGetNative(s);
    MacSocketInfo *socketInfo = eventDispatcher->macSockets.value(nativeSocket);
    QEvent notifierEvent(QEvent::SockAct);

    // There is a race condition that happen where we disable the notifier and
    // the kernel still has a notification to pass on. We then get this
    // notification after we've successfully disabled the CFSocket, but our Qt
    // notifier is now gone. The upshot is we have to check the notifier
    // everytime.
    if (callbackType == kCFSocketReadCallBack) {
        if (socketInfo->readNotifier)
            QApplication::sendEvent(socketInfo->readNotifier, &notifierEvent);
    } else if (callbackType == kCFSocketWriteCallBack) {
        if (socketInfo->writeNotifier)
            QApplication::sendEvent(socketInfo->writeNotifier, &notifierEvent);
    }
}

/*
    Adds a loop source for the given socket to the current run loop.
*/
CFRunLoopSourceRef qt_mac_add_socket_to_runloop(const CFSocketRef socket)
{
    CFRunLoopSourceRef loopSource = CFSocketCreateRunLoopSource(kCFAllocatorDefault, socket, 0);
    if (!loopSource)
        return 0;

    CFRunLoopAddSource(mainRunLoop(), loopSource, kCFRunLoopCommonModes);
    return loopSource;
}

/*
    Removes the loop source for the given socket from the current run loop.
*/
void qt_mac_remove_socket_from_runloop(const CFSocketRef socket, CFRunLoopSourceRef runloop)
{
    Q_ASSERT(runloop);
    CFRunLoopRemoveSource(mainRunLoop(), runloop, kCFRunLoopCommonModes);
    CFSocketDisableCallBacks(socket, kCFSocketReadCallBack);
    CFSocketDisableCallBacks(socket, kCFSocketWriteCallBack);
    CFRunLoopSourceInvalidate(runloop);
}

/*
    Register a QSocketNotifier with the mac event system by creating a CFSocket with
    with a read/write callback.

    Qt has separate socket notifiers for reading and writing, but on the mac there is
    a limitation of one CFSocket object for each native socket.
*/
void QEventDispatcherMac::registerSocketNotifier(QSocketNotifier *notifier)
{
    Q_ASSERT(notifier);
    int nativeSocket = notifier->socket();
    int type = notifier->type();
#ifndef QT_NO_DEBUG
    if (nativeSocket < 0 || nativeSocket > FD_SETSIZE) {
        qWarning("QSocketNotifier: Internal error");
        return;
    } else if (notifier->thread() != thread()
               || thread() != QThread::currentThread()) {
        qWarning("QSocketNotifier: socket notifiers cannot be enabled from another thread");
        return;
    }
#endif

    Q_D(QEventDispatcherMac);

    if (type == QSocketNotifier::Exception) {
        qWarning("QSocketNotifier::Exception is not supported on Mac OS X");
        return;
    }

    // Check if we have a CFSocket for the native socket, create one if not.
    MacSocketInfo *socketInfo = d->macSockets.value(nativeSocket);
    if (!socketInfo) {
        socketInfo = new MacSocketInfo();

        // Create CFSocket, specify that we want both read and write callbacks (the callbacks
        // are enabled/disabled later on).
        const int callbackTypes = kCFSocketReadCallBack | kCFSocketWriteCallBack;
        CFSocketContext context = {0, d, 0, 0, 0};
        socketInfo->socket = CFSocketCreateWithNative(kCFAllocatorDefault, nativeSocket, callbackTypes, qt_mac_socket_callback, &context);
        if (CFSocketIsValid(socketInfo->socket) == false) {
            qWarning("QEventDispatcherMac::registerSocketNotifier: Failed to create CFSocket");
            return;
        }

        CFOptionFlags flags = CFSocketGetSocketFlags(socketInfo->socket);
        flags |= kCFSocketAutomaticallyReenableWriteCallBack; //QSocketNotifier stays enabled after a write
        flags &= ~kCFSocketCloseOnInvalidate; //QSocketNotifier doesn't close the socket upon destruction/invalidation
        CFSocketSetSocketFlags(socketInfo->socket, flags);

        // Add CFSocket to runloop.
        if(!(socketInfo->runloop = qt_mac_add_socket_to_runloop(socketInfo->socket))) {
            qWarning("QEventDispatcherMac::registerSocketNotifier: Failed to add CFSocket to runloop");
            CFSocketInvalidate(socketInfo->socket);
            CFRelease(socketInfo->socket);
            return;
        }

        // Disable both callback types by default. This must be done after
        // we add the CFSocket to the runloop, or else these calls will have
        // no effect.
        CFSocketDisableCallBacks(socketInfo->socket, kCFSocketReadCallBack);
        CFSocketDisableCallBacks(socketInfo->socket, kCFSocketWriteCallBack);

        d->macSockets.insert(nativeSocket, socketInfo);
    }

    // Increment read/write counters and select enable callbacks if necessary.
    if (type == QSocketNotifier::Read) {
        Q_ASSERT(socketInfo->readNotifier == 0);
        socketInfo->readNotifier = notifier;
        CFSocketEnableCallBacks(socketInfo->socket, kCFSocketReadCallBack);
    } else if (type == QSocketNotifier::Write) {
        Q_ASSERT(socketInfo->writeNotifier == 0);
        socketInfo->writeNotifier = notifier;
        CFSocketEnableCallBacks(socketInfo->socket, kCFSocketWriteCallBack);
    }
}

/*
    Unregister QSocketNotifer. The CFSocket correspoding to this notifier is
    removed from the runloop of this is the last notifier that users
    that CFSocket.
*/
void QEventDispatcherMac::unregisterSocketNotifier(QSocketNotifier *notifier)
{
    Q_ASSERT(notifier);
    int nativeSocket = notifier->socket();
    int type = notifier->type();
#ifndef QT_NO_DEBUG
    if (nativeSocket < 0 || nativeSocket > FD_SETSIZE) {
        qWarning("QSocketNotifier: Internal error");
        return;
    } else if (notifier->thread() != thread() || thread() != QThread::currentThread()) {
        qWarning("QSocketNotifier: socket notifiers cannot be disabled from another thread");
        return;
    }
#endif

    Q_D(QEventDispatcherMac);

    if (type == QSocketNotifier::Exception) {
        qWarning("QSocketNotifier::Exception is not supported on Mac OS X");
        return;
    }
    MacSocketInfo *socketInfo = d->macSockets.value(nativeSocket);
    if (!socketInfo) {
        qWarning("QEventDispatcherMac::unregisterSocketNotifier: Tried to unregister a not registered notifier");
        return;
    }

    // Decrement read/write counters and disable callbacks if necessary.
    if (type == QSocketNotifier::Read) {
        Q_ASSERT(notifier == socketInfo->readNotifier);
        socketInfo->readNotifier = 0;
        CFSocketDisableCallBacks(socketInfo->socket, kCFSocketReadCallBack);
    } else if (type == QSocketNotifier::Write) {
        Q_ASSERT(notifier == socketInfo->writeNotifier);
        socketInfo->writeNotifier = 0;
        CFSocketDisableCallBacks(socketInfo->socket, kCFSocketWriteCallBack);
    }

    // Remove CFSocket from runloop if this was the last QSocketNotifier.
    if (socketInfo->readNotifier == 0 && socketInfo->writeNotifier == 0) {
        if (CFSocketIsValid(socketInfo->socket))
            qt_mac_remove_socket_from_runloop(socketInfo->socket, socketInfo->runloop);
        CFRunLoopSourceInvalidate(socketInfo->runloop);
        CFRelease(socketInfo->runloop);
        CFSocketInvalidate(socketInfo->socket);
        CFRelease(socketInfo->socket);
        delete socketInfo;
        d->macSockets.remove(nativeSocket);
    }
}

bool QEventDispatcherMac::hasPendingEvents()
{
    extern uint qGlobalPostedEventsCount();
    return qGlobalPostedEventsCount() || (qt_is_gui_used && GetNumEventsInQueue(GetMainEventQueue()));
}


static bool qt_mac_send_event(QEventLoop::ProcessEventsFlags, OSEventRef event, OSWindowRef pt)
{
#ifndef QT_MAC_USE_COCOA
    if(pt && SendEventToWindow(event, pt) != eventNotHandledErr)
        return true;
    return !SendEventToEventTarget(event, GetEventDispatcherTarget());
#else // QT_MAC_USE_COCOA
    if (pt)
        [pt sendEvent:event];
    else
        [NSApp sendEvent:event];
    return true;
#endif
}

#ifdef QT_MAC_USE_COCOA
static bool IsMouseOrKeyEvent( NSEvent* event )
{
    bool    result    = false;
    
    switch( [event type] )
    {
        case NSLeftMouseDown:              
        case NSLeftMouseUp:      
        case NSRightMouseDown:   
        case NSRightMouseUp:     
        case NSMouseMoved:                // ??
        case NSLeftMouseDragged: 
        case NSRightMouseDragged:
        case NSMouseEntered:     
        case NSMouseExited:      
        case NSKeyDown:          
        case NSKeyUp:            
        case NSFlagsChanged:            // key modifiers changed?
        case NSCursorUpdate:            // ??
        case NSScrollWheel:      
        case NSTabletPoint:      
        case NSTabletProximity:  
        case NSOtherMouseDown:   
        case NSOtherMouseUp:     
        case NSOtherMouseDragged:
#ifndef QT_NO_GESTURES
#if MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_6
        case NSEventTypeGesture: // touch events
        case NSEventTypeMagnify:
        case NSEventTypeSwipe:
        case NSEventTypeRotate:
        case NSEventTypeBeginGesture:
        case NSEventTypeEndGesture:
#endif
#endif // QT_NO_GESTURES
            result    = true;
        break;

        default:
        break;
    }
    return result;
}
#endif

static inline void qt_mac_waitForMoreEvents()
{
#ifndef QT_MAC_USE_COCOA
    while (CFRunLoopRunInMode(kCFRunLoopDefaultMode, 1.0e20, true) == kCFRunLoopRunTimedOut) ;
#else
    // If no event exist in the cocoa event que, wait
    // (and free up cpu time) until at least one event occur.
    // This implementation is a bit on the edge, but seems to
    // work fine:
    NSEvent* event = [NSApp nextEventMatchingMask:NSAnyEventMask
        untilDate:[NSDate distantFuture]
        inMode:NSDefaultRunLoopMode
        dequeue:YES];
    if (event)
        [NSApp postEvent:event atStart:YES];
#endif
}

#ifdef QT_MAC_USE_COCOA
static inline void qt_mac_waitForMoreModalSessionEvents()
{
    // If no event exist in the cocoa event que, wait
    // (and free up cpu time) until at least one event occur.
    // This implementation is a bit on the edge, but seems to
    // work fine:
    NSEvent* event = [NSApp nextEventMatchingMask:NSAnyEventMask
        untilDate:[NSDate distantFuture]
        inMode:NSModalPanelRunLoopMode
        dequeue:YES];
    if (event)
        [NSApp postEvent:event atStart:YES];
}
#endif

bool QEventDispatcherMac::processEvents(QEventLoop::ProcessEventsFlags flags)
{
    Q_D(QEventDispatcherMac);
    d->interrupt = false;

#ifdef QT_MAC_USE_COCOA
    bool interruptLater = false;
    QtMacInterruptDispatcherHelp::cancelInterruptLater();
#endif

    // In case we end up recursing while we now process events, make sure
    // that we send remaining posted Qt events before this call returns:
    wakeUp();
    emit awake();

    bool excludeUserEvents = flags & QEventLoop::ExcludeUserInputEvents;
    bool retVal = false;
    forever {
        if (d->interrupt)
            break;

#ifdef QT_MAC_USE_COCOA
        QMacCocoaAutoReleasePool pool;
        NSEvent* event = 0;

        // First, send all previously excluded input events, if any:
        if (!excludeUserEvents) {
            while (!d->queuedUserInputEvents.isEmpty()) {
                event = static_cast<NSEvent *>(d->queuedUserInputEvents.takeFirst());
                if (!filterEvent(event)) {
                    qt_mac_send_event(flags, event, 0);
                    retVal = true;
                }
                [event release];
            }
        }

        // If Qt is used as a plugin, or as an extension in a native cocoa
        // application, we should not run or stop NSApplication; This will be
        // done from the application itself. And if processEvents is called
        // manually (rather than from a QEventLoop), we cannot enter a tight
        // loop and block this call, but instead we need to return after one flush.
        // Finally, if we are to exclude user input events, we cannot call [NSApp run]
        // as we then loose control over which events gets dispatched:
        const bool canExec_3rdParty = d->nsAppRunCalledByQt || ![NSApp isRunning];
        const bool canExec_Qt = !excludeUserEvents &&
                (flags & QEventLoop::DialogExec || flags & QEventLoop::EventLoopExec) ;

        if (canExec_Qt && canExec_3rdParty) {
            // We can use exec-mode, meaning that we can stay in a tight loop until
            // interrupted. This is mostly an optimization, but it allow us to use
            // [NSApp run], which is the normal code path for cocoa applications.
            if (NSModalSession session = d->currentModalSession()) {
                QBoolBlocker execGuard(d->currentExecIsNSAppRun, false);
                while ([NSApp runModalSession:session] == NSRunContinuesResponse && !d->interrupt)
                    qt_mac_waitForMoreModalSessionEvents();

                if (!d->interrupt && session == d->currentModalSessionCached) {
                    // Someone called [NSApp stopModal:] from outside the event
                    // dispatcher (e.g to stop a native dialog). But that call wrongly stopped
                    // 'session' as well. As a result, we need to restart all internal sessions:
                    d->temporarilyStopAllModalSessions();
                }
            } else {
                d->nsAppRunCalledByQt = true;
                QBoolBlocker execGuard(d->currentExecIsNSAppRun, true);
                [NSApp run];
            }
            retVal = true;
        } else {
            // We cannot block the thread (and run in a tight loop).
            // Instead we will process all current pending events and return.
            d->ensureNSAppInitialized();
            if (NSModalSession session = d->currentModalSession()) {
                // INVARIANT: a modal window is executing.
                if (!excludeUserEvents) {
                    // Since we can dispatch all kinds of events, we choose
                    // to use cocoa's native way of running modal sessions:
                    if (flags & QEventLoop::WaitForMoreEvents)
                        qt_mac_waitForMoreModalSessionEvents();
                    NSInteger status = [NSApp runModalSession:session];
                    if (status != NSRunContinuesResponse && session == d->currentModalSessionCached) {
                        // INVARIANT: Someone called [NSApp stopModal:] from outside the event
                        // dispatcher (e.g to stop a native dialog). But that call wrongly stopped
                        // 'session' as well. As a result, we need to restart all internal sessions:
                        d->temporarilyStopAllModalSessions();
                    }
                    retVal = true;
                } else do {
                    // Dispatch all non-user events (but que non-user events up for later). In
                    // this case, we need more control over which events gets dispatched, and
                    // cannot use [NSApp runModalSession:session]:
                    event = [NSApp nextEventMatchingMask:NSAnyEventMask
                    untilDate:nil
                    inMode:NSModalPanelRunLoopMode
                    dequeue: YES];

                    if (event) {
                        if (IsMouseOrKeyEvent(event)) {
                            [event retain];
                            d->queuedUserInputEvents.append(event);
                            continue;
                        }
                        if (!filterEvent(event) && qt_mac_send_event(flags, event, 0))
                            retVal = true;
                    }
                } while (!d->interrupt && event != nil);
            } else do {
                // INVARIANT: No modal window is executing.
                event = [NSApp nextEventMatchingMask:NSAnyEventMask
                untilDate:nil
                inMode:NSDefaultRunLoopMode
                dequeue: YES];

                if (event) {
                    if (flags & QEventLoop::ExcludeUserInputEvents) {
                        if (IsMouseOrKeyEvent(event)) {
                            [event retain];
                            d->queuedUserInputEvents.append(event);
                            continue;
                        }
                    }
                    if (!filterEvent(event) && qt_mac_send_event(flags, event, 0))
                        retVal = true;
                }
            } while (!d->interrupt && event != nil);

            // Be sure to flush the Qt posted events when not using exec mode
            // (exec mode will always do this call from the event loop source):
            if (!d->interrupt)
                QCoreApplicationPrivate::sendPostedEvents(0, 0, d->threadData);

            // Since the window that holds modality might have changed while processing
            // events, we we need to interrupt when we return back the previous process
            // event recursion to ensure that we spin the correct modal session.
            // We do the interruptLater at the end of the function to ensure that we don't
            // disturb the 'wait for more events' below (as deleteLater will post an event):
            interruptLater = true;
        }
#else
        do {
            EventRef event;
            if (!(flags & QEventLoop::ExcludeUserInputEvents)
                    && !d->queuedUserInputEvents.isEmpty()) {
                // process a pending user input event
                event = static_cast<EventRef>(d->queuedUserInputEvents.takeFirst());
            } else {
                OSStatus err = ReceiveNextEvent(0,0, kEventDurationNoWait, true, &event);
                if(err != noErr)
                    continue;
                // else
                if (flags & QEventLoop::ExcludeUserInputEvents) {
                    UInt32 ekind = GetEventKind(event),
                           eclass = GetEventClass(event);
                    switch(eclass) {
                        case kEventClassQt:
                            if(ekind != kEventQtRequestContext)
                                break;
                            // fall through
                        case kEventClassMouse:
                        case kEventClassKeyboard:
                            d->queuedUserInputEvents.append(event);
                            continue;
                    }
                }
            }

            if (!filterEvent(&event) && qt_mac_send_event(flags, event, 0))
                retVal = true;
            ReleaseEvent(event);
        } while(!d->interrupt && GetNumEventsInQueue(GetMainEventQueue()) > 0);

#endif

        bool canWait = (d->threadData->canWait
                && !retVal
                && !d->interrupt
                && (flags & QEventLoop::WaitForMoreEvents));
        if (canWait) {
            // INVARIANT: We haven't processed any events yet. And we're told
            // to stay inside this function until at least one event is processed.
            qt_mac_waitForMoreEvents();
            flags &= ~QEventLoop::WaitForMoreEvents;
        } else {
            // Done with event processing for now.
            // Leave the function:
            break;
        }
    }

    // If we're interrupted, we need to interrupt the _current_
    // recursion as well to check if it is  still supposed to be
    // executing. This way we wind down the stack until we land
    // on a recursion that again calls processEvents (typically
    // from QEventLoop), and set interrupt to false:
    if (d->interrupt)
        interrupt();

#ifdef QT_MAC_USE_COCOA
    if (interruptLater)
        QtMacInterruptDispatcherHelp::interruptLater();
#endif

    return retVal;
}

void QEventDispatcherMac::wakeUp()
{
    Q_D(QEventDispatcherMac);
    d->serialNumber.ref();
    CFRunLoopSourceSignal(d->postedEventsSource);
    CFRunLoopWakeUp(mainRunLoop());
}

void QEventDispatcherMac::flush()
{
    if(qApp) {
        QWidgetList tlws = QApplication::topLevelWidgets();
        for(int i = 0; i < tlws.size(); i++) {
            QWidget *tlw = tlws.at(i);
            if(tlw->isVisible())
                macWindowFlush(qt_mac_window_for(tlw));
        }
    }
}

/*****************************************************************************
  QEventDispatcherMac Implementation
 *****************************************************************************/
MacTimerHash QEventDispatcherMacPrivate::macTimerHash;
bool QEventDispatcherMacPrivate::blockSendPostedEvents = false;
bool QEventDispatcherMacPrivate::interrupt = false;

#ifdef QT_MAC_USE_COCOA
QStack<QCocoaModalSessionInfo> QEventDispatcherMacPrivate::cocoaModalSessionStack;
bool QEventDispatcherMacPrivate::currentExecIsNSAppRun = false;
bool QEventDispatcherMacPrivate::nsAppRunCalledByQt = false;
bool QEventDispatcherMacPrivate::cleanupModalSessionsNeeded = false;
NSModalSession QEventDispatcherMacPrivate::currentModalSessionCached = 0;

void QEventDispatcherMacPrivate::ensureNSAppInitialized()
{
    // Some elements in Cocoa require NSApplication to be running before
    // they get fully initialized, in particular the menu bar. This
    // function is intended for cases where a dialog is told to execute before
    // QApplication::exec is called, or the application spins the events loop
    // manually rather than calling QApplication:exec.
    // The function makes sure that NSApplication starts running, but stops
    // it again as soon as the send posted events callback is called. That way
    // we let Cocoa finish the initialization it seems to need. We'll only
    // apply this trick at most once for any application, and we avoid doing it
    // for the common case where main just starts QApplication::exec.
    if (nsAppRunCalledByQt || [NSApp isRunning])
        return;
    nsAppRunCalledByQt = true;
    QBoolBlocker block1(interrupt, true);
    QBoolBlocker block2(currentExecIsNSAppRun, true);
    [NSApp run];
}

void QEventDispatcherMacPrivate::temporarilyStopAllModalSessions()
{
    // Flush, and Stop, all created modal session, and as
    // such, make them pending again. The next call to
    // currentModalSession will recreate them again. The
    // reason to stop all session like this is that otherwise
    // a call [NSApp stop] would not stop NSApp, but rather
    // the current modal session. So if we need to stop NSApp
    // we need to stop all the modal session first. To avoid changing
    // the stacking order of the windows while doing so, we put
    // up a block that is used in QCocoaWindow and QCocoaPanel:
    int stackSize = cocoaModalSessionStack.size();
    for (int i=0; i<stackSize; ++i) {
        QCocoaModalSessionInfo &info = cocoaModalSessionStack[i];
        if (info.session) {
            [NSApp endModalSession:info.session];
            info.session = 0;
        }
    }
    currentModalSessionCached = 0;
}

NSModalSession QEventDispatcherMacPrivate::currentModalSession()
{
    // If we have one or more modal windows, this function will create
    // a session for each of those, and return the one for the top.
    if (currentModalSessionCached)
        return currentModalSessionCached;

    if (cocoaModalSessionStack.isEmpty())
        return 0;

    int sessionCount = cocoaModalSessionStack.size();
    for (int i=0; i<sessionCount; ++i) {
        QCocoaModalSessionInfo &info = cocoaModalSessionStack[i];
        if (!info.widget)
            continue;
        if (info.widget->testAttribute(Qt::WA_DontShowOnScreen))
            continue;
        if (!info.session) {
            QMacCocoaAutoReleasePool pool;
            NSWindow *window = qt_mac_window_for(info.widget);
            if (!window)
                continue;

            ensureNSAppInitialized();
            QBoolBlocker block1(blockSendPostedEvents, true);
            info.nswindow = window;
            [(NSWindow*) info.nswindow retain];
            int levelBeforeEnterModal = [window level];
            info.session = [NSApp beginModalSessionForWindow:window];
            // Make sure we don't stack the window lower that it was before
            // entering modal, in case it e.g. had the stays-on-top flag set:
            if (levelBeforeEnterModal > [window level])
                [window setLevel:levelBeforeEnterModal];
        }
        currentModalSessionCached = info.session;
        cleanupModalSessionsNeeded = false;
    }
    return currentModalSessionCached;
}

static void setChildrenWorksWhenModal(QWidget *widget, bool worksWhenModal)
{
    // For NSPanels (but not NSWindows, sadly), we can set the flag
    // worksWhenModal, so that they are active even when they are not modal. 
    QList<QDialog *> dialogs = widget->findChildren<QDialog *>();
    for (int i=0; i<dialogs.size(); ++i){
        NSWindow *window = qt_mac_window_for(dialogs[i]);
        if (window && [window isKindOfClass:[NSPanel class]]) {
            [static_cast<NSPanel *>(window) setWorksWhenModal:worksWhenModal];
            if (worksWhenModal && [window isVisible]){
                [window orderFront:window];
            }
        }
    }
}

void QEventDispatcherMacPrivate::updateChildrenWorksWhenModal()
{
    // Make the dialog children of the widget
    // active. And make the dialog children of
    // the previous modal dialog unactive again:
    QMacCocoaAutoReleasePool pool;
    int size = cocoaModalSessionStack.size();
    if (size > 0){
        if (QWidget *prevModal = cocoaModalSessionStack[size-1].widget)
            setChildrenWorksWhenModal(prevModal, true);
        if (size > 1){
            if (QWidget *prevModal = cocoaModalSessionStack[size-2].widget)
                setChildrenWorksWhenModal(prevModal, false);
        }
    }
}

void QEventDispatcherMacPrivate::cleanupModalSessions()
{
    // Go through the list of modal sessions, and end those
    // that no longer has a widget assosiated; no widget means
    // the the session has logically ended. The reason we wait like
    // this to actually end the sessions for real (rather than at the
    // point they were marked as stopped), is that ending a session
    // when no other session runs below it on the stack will make cocoa
    // drop some events on the floor. 
    QMacCocoaAutoReleasePool pool;
    int stackSize = cocoaModalSessionStack.size();

    for (int i=stackSize-1; i>=0; --i) {
        QCocoaModalSessionInfo &info = cocoaModalSessionStack[i];
        if (info.widget) {
            // This session has a widget, and is therefore not marked
            // as stopped. So just make it current. There might still be other
            // stopped sessions on the stack, but those will be stopped on
            // a later "cleanup" call.
            currentModalSessionCached = info.session;
            break;
        }
        cocoaModalSessionStack.remove(i);
        currentModalSessionCached = 0;
        if (info.session) {
            [NSApp endModalSession:info.session];
            [(NSWindow *)info.nswindow release];
        }
    }

    updateChildrenWorksWhenModal();
    cleanupModalSessionsNeeded = false;
}

void QEventDispatcherMacPrivate::beginModalSession(QWidget *widget)
{
    // Add a new, empty (null), NSModalSession to the stack.
    // It will become active the next time QEventDispatcher::processEvents is called.
    // A QCocoaModalSessionInfo is considered pending to become active if the widget pointer 
    // is non-zero, and the session pointer is zero (it will become active upon a call to
    // currentModalSession). A QCocoaModalSessionInfo is considered pending to be stopped if
    // the widget pointer is zero, and the session pointer is non-zero (it will be fully
    // stopped in cleanupModalSessions()).
    QCocoaModalSessionInfo info = {widget, 0, 0};
    cocoaModalSessionStack.push(info);
    updateChildrenWorksWhenModal();
    currentModalSessionCached = 0;
}

void QEventDispatcherMacPrivate::endModalSession(QWidget *widget)
{
    // Mark all sessions attached to widget as pending to be stopped. We do this
    // by setting the widget pointer to zero, but leave the session pointer.
    // We don't tell cocoa to stop any sessions just yet, because cocoa only understands
    // when we stop the _current_ modal session (which is the session on top of
    // the stack, and might not belong to 'widget'). 
    int stackSize = cocoaModalSessionStack.size();
    for (int i=stackSize-1; i>=0; --i) {
        QCocoaModalSessionInfo &info = cocoaModalSessionStack[i];
        if (info.widget == widget) {
            info.widget = 0;
            if (i == stackSize-1) {
                // The top sessions ended. Interrupt the event dispatcher
                // to start spinning the correct session immidiatly: 
                currentModalSessionCached = 0;
                cleanupModalSessionsNeeded = true;
                QEventDispatcherMac::instance()->interrupt();
            }
        }
    }
}

#endif

QEventDispatcherMacPrivate::QEventDispatcherMacPrivate()
{
}

QEventDispatcherMac::QEventDispatcherMac(QObject *parent)
    : QAbstractEventDispatcher(*new QEventDispatcherMacPrivate, parent)
{
    Q_D(QEventDispatcherMac);
    CFRunLoopSourceContext context;
    bzero(&context, sizeof(CFRunLoopSourceContext));
    context.info = d;
    context.equal = QEventDispatcherMacPrivate::postedEventSourceEqualCallback;
    context.perform = QEventDispatcherMacPrivate::postedEventsSourcePerformCallback;
    d->postedEventsSource = CFRunLoopSourceCreate(0, 0, &context);
    Q_ASSERT(d->postedEventsSource);
    CFRunLoopAddSource(mainRunLoop(), d->postedEventsSource, kCFRunLoopCommonModes);

    CFRunLoopObserverContext observerContext;
    bzero(&observerContext, sizeof(CFRunLoopObserverContext));
    observerContext.info = this;
    d->waitingObserver = CFRunLoopObserverCreate(kCFAllocatorDefault,
                                                 kCFRunLoopBeforeWaiting | kCFRunLoopAfterWaiting,
                                                 true, 0,
                                                 QEventDispatcherMacPrivate::waitingObserverCallback,
                                                 &observerContext);
    CFRunLoopAddObserver(mainRunLoop(), d->waitingObserver, kCFRunLoopCommonModes);

    /* The first cycle in the loop adds the source and the events of the source
       are not processed.
       We use an observer to process the posted events for the first
       execution of the loop. */
    CFRunLoopObserverContext firstTimeObserverContext;
    bzero(&firstTimeObserverContext, sizeof(CFRunLoopObserverContext));
    firstTimeObserverContext.info = d;
    d->firstTimeObserver = CFRunLoopObserverCreate(kCFAllocatorDefault,
                                                   kCFRunLoopEntry,
                                                   /* repeats = */ false,
                                                   0,
                                                   QEventDispatcherMacPrivate::firstLoopEntry,
                                                   &firstTimeObserverContext);
    CFRunLoopAddObserver(mainRunLoop(), d->firstTimeObserver, kCFRunLoopCommonModes);
}

void QEventDispatcherMacPrivate::waitingObserverCallback(CFRunLoopObserverRef,
                                                          CFRunLoopActivity activity, void *info)
{
    if (activity == kCFRunLoopBeforeWaiting)
        emit static_cast<QEventDispatcherMac*>(info)->aboutToBlock();
    else
        emit static_cast<QEventDispatcherMac*>(info)->awake();
}

Boolean QEventDispatcherMacPrivate::postedEventSourceEqualCallback(const void *info1, const void *info2)
{
    return info1 == info2;
}

inline static void processPostedEvents(QEventDispatcherMacPrivate *const d, const bool blockSendPostedEvents)
{
    if (blockSendPostedEvents) {
        // We're told to not send posted events (because the event dispatcher
        // is currently working on setting up the correct session to run). But
        // we still need to make sure that we don't fall asleep until pending events
        // are sendt, so we just signal this need, and return:
        CFRunLoopSourceSignal(d->postedEventsSource);
        return;
    }

#ifdef QT_MAC_USE_COCOA
    if (d->cleanupModalSessionsNeeded)
        d->cleanupModalSessions();
#endif

    if (d->interrupt) {
#ifdef QT_MAC_USE_COCOA
        if (d->currentExecIsNSAppRun) {
            // The event dispatcher has been interrupted. But since
            // [NSApplication run] is running the event loop, we
            // delayed stopping it until now (to let cocoa process 
            // pending cocoa events first).
            if (d->currentModalSessionCached)
                d->temporarilyStopAllModalSessions();
            [NSApp stop:NSApp];
            d->cancelWaitForMoreEvents();
        }
#endif
        return;
    }

    if (!d->threadData->canWait || (d->serialNumber != d->lastSerial)) {
        d->lastSerial = d->serialNumber;
        QApplicationPrivate::sendPostedEvents(0, 0, d->threadData);
    }
}

void QEventDispatcherMacPrivate::firstLoopEntry(CFRunLoopObserverRef ref,
                                                CFRunLoopActivity activity,
                                                void *info)
{
    Q_UNUSED(ref);
    Q_UNUSED(activity);
#ifdef QT_MAC_USE_COCOA
    QApplicationPrivate::qt_initAfterNSAppStarted();
#endif
    processPostedEvents(static_cast<QEventDispatcherMacPrivate *>(info), blockSendPostedEvents);
}

void QEventDispatcherMacPrivate::postedEventsSourcePerformCallback(void *info)
{
    processPostedEvents(static_cast<QEventDispatcherMacPrivate *>(info), blockSendPostedEvents);
}

#ifdef QT_MAC_USE_COCOA
void QEventDispatcherMacPrivate::cancelWaitForMoreEvents()
{
    // In case the event dispatcher is waiting for more
    // events somewhere, we post a dummy event to wake it up:
    QMacCocoaAutoReleasePool pool;
    [NSApp postEvent:[NSEvent otherEventWithType:NSApplicationDefined location:NSZeroPoint
        modifierFlags:0 timestamp:0. windowNumber:0 context:0
        subtype:QtCocoaEventSubTypeWakeup data1:0 data2:0] atStart:NO];
}
#endif

void QEventDispatcherMac::interrupt()
{
    Q_D(QEventDispatcherMac);
    d->interrupt = true;
    wakeUp();

#ifndef QT_MAC_USE_COCOA
    CFRunLoopStop(mainRunLoop());
#else
    // We do nothing more here than setting d->interrupt = true, and
    // poke the event loop if it is sleeping. Actually stopping
    // NSApp, or the current modal session, is done inside the send
    // posted events callback. We do this to ensure that all current pending
    // cocoa events gets delivered before we stop. Otherwise, if we now stop
    // the last event loop recursion, cocoa will just drop pending posted
    // events on the floor before we get a chance to reestablish a new session.
    d->cancelWaitForMoreEvents();
#endif
}

QEventDispatcherMac::~QEventDispatcherMac()
{
    Q_D(QEventDispatcherMac);
    //timer cleanup
    MacTimerHash::iterator it = QEventDispatcherMacPrivate::macTimerHash.begin();
    while (it != QEventDispatcherMacPrivate::macTimerHash.end()) {
        MacTimerInfo *t = it.value();
        if (t->runLoopTimer) {
            CFRunLoopTimerInvalidate(t->runLoopTimer);
            CFRelease(t->runLoopTimer);
        }
        delete t;
        ++it;
    }
    QEventDispatcherMacPrivate::macTimerHash.clear();

    // Remove CFSockets from the runloop.
    for (MacSocketHash::ConstIterator it = d->macSockets.constBegin(); it != d->macSockets.constEnd(); ++it) {
        MacSocketInfo *socketInfo = (*it);
        if (CFSocketIsValid(socketInfo->socket)) {
            qt_mac_remove_socket_from_runloop(socketInfo->socket, socketInfo->runloop);
            CFRunLoopSourceInvalidate(socketInfo->runloop);
            CFRelease(socketInfo->runloop);
            CFSocketInvalidate(socketInfo->socket);
            CFRelease(socketInfo->socket);
        }
    }
    CFRunLoopRemoveSource(mainRunLoop(), d->postedEventsSource, kCFRunLoopCommonModes);
    CFRelease(d->postedEventsSource);

    CFRunLoopObserverInvalidate(d->waitingObserver);
    CFRelease(d->waitingObserver);

    CFRunLoopObserverInvalidate(d->firstTimeObserver);
    CFRelease(d->firstTimeObserver);
}

#ifdef QT_MAC_USE_COCOA

QtMacInterruptDispatcherHelp* QtMacInterruptDispatcherHelp::instance = 0;

QtMacInterruptDispatcherHelp::QtMacInterruptDispatcherHelp() : cancelled(false)
{
    // The whole point of this class is that we enable a way to interrupt
    // the event dispatcher when returning back to a lower recursion level
    // than where interruptLater was called. This is needed to detect if
    // [NSApp run] should still be running at the recursion level it is at.
    // Since the interrupt is canceled if processEvents is called before
    // this object gets deleted, we also avoid interrupting unnecessary.
    deleteLater();
}

QtMacInterruptDispatcherHelp::~QtMacInterruptDispatcherHelp()
{
    if (cancelled)
        return;
    instance = 0;
    QEventDispatcherMac::instance()->interrupt();
}

void QtMacInterruptDispatcherHelp::cancelInterruptLater()
{
    if (!instance)
        return;
    instance->cancelled = true;
    delete instance;
    instance = 0;
}

void QtMacInterruptDispatcherHelp::interruptLater()
{
    cancelInterruptLater();
    instance = new QtMacInterruptDispatcherHelp;
}

#endif

QT_END_NAMESPACE