/******************************************************************************** Copyright (C) 1992-2006 Trolltech ASA. All rights reserved.**** This file is part of the QtCore module of the Qt Toolkit.**** This file may be used under the terms of the GNU General Public** License version 2.0 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 GNU** General Public Licensing requirements will be met:** http://www.trolltech.com/products/qt/opensource.html**** If you are unsure which license is appropriate for your use, please** review the following information:** http://www.trolltech.com/products/qt/licensing.html or contact the** sales department at sales@trolltech.com.**** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.******************************************************************************/#include "qeventloop.h"#include "qabstracteventdispatcher.h"#include "qcoreapplication.h"#include "qdatetime.h"#include "qobject_p.h"#include <private/qthread_p.h>class QEventLoopPrivate : public QObjectPrivate{    Q_DECLARE_PUBLIC(QEventLoop)public:    inline QEventLoopPrivate()        : exit(true), inExec(false), returnCode(-1)    { }    bool exit, inExec;    int returnCode;};/*!    \class QEventLoop    \brief The QEventLoop class provides a means of entering and leaving an event loop.    At any time, you can create a QEventLoop object and call exec()    on it to start a local event loop. From within the event loop,    calling exit() will force exec() to return.    \sa QAbstractEventDispatcher*//*!    \enum QEventLoop::ProcessEventsFlag    This enum controls the types of events processed by the    processEvents() functions.    \value AllEvents All events are processed    \value ExcludeUserInputEvents Do not process user input events,    such as ButtonPress and KeyPress. Note that the events are not    discarded; they will be delivered the next time processEvents() is    called without the ExcludeUserInputEvents flag.    \value ExcludeSocketNotifiers Do not process socket notifier    events. Note that the events are not discarded; they will be    delivered the next time processEvents() is called without the    ExcludeSocketNotifiers flag.    \value WaitForMoreEvents Wait for events if no pending events are    available.    \value DeferredDeletion Allow objects to be queued for deletion    at a later time.    \value X11ExcludeTimers    \omitvalue ExcludeUserInput    \omitvalue WaitForMore    \sa processEvents()*//*!    Constructs an event loop object with the given \a parent.*/QEventLoop::QEventLoop(QObject *parent)    : QObject(*new QEventLoopPrivate, parent){    Q_D(QEventLoop);    if (!QCoreApplication::instance()) {        qWarning("QEventLoop: Cannot be used without QApplication");    } else if (!d->threadData->eventDispatcher) {        QThreadPrivate::createEventDispatcher(d->threadData);    }}/*!    Destroys the event loop object.*/QEventLoop::~QEventLoop(){ }/*!    Processes pending events that match \a flags until there are no    more events to process. Returns true if pending events were handled;    otherwise returns false.    This function is especially useful if you have a long running    operation and want to show its progress without allowing user    input; i.e. by using the \l ExcludeUserInputEvents flag.    This function is simply a wrapper for    QAbstractEventDispatcher::processEvents(). See the documentation    for that function for details.*/bool QEventLoop::processEvents(ProcessEventsFlags flags){    Q_D(QEventLoop);    if (!d->threadData->eventDispatcher)        return false;    return d->threadData->eventDispatcher->processEvents(flags);}/*!    Enters the main event loop and waits until exit() is called.    Returns the value that was passed to exit().    If \a flags are specified, only events of the types allowed by    the \a flags will be processed.    It is necessary to call this function to start event handling. The    main event loop receives events from the window system and    dispatches these to the application widgets.    Generally speaking, no user interaction can take place before    calling exec(). As a special case, modal widgets like QMessageBox    can be used before calling exec(), because modal widgets     use their own local event loop.    To make your application perform idle processing (i.e. executing a    special function whenever there are no pending events), use a    QTimer with 0 timeout. More sophisticated idle processing schemes    can be achieved using processEvents().    \sa QApplication::quit(), exit(), processEvents()*/int QEventLoop::exec(ProcessEventsFlags flags){    Q_D(QEventLoop);    if (d->threadData->quitNow)        return -1;    if (d->inExec) {        qWarning("QEventLoop::exec: instance %p has already called exec()", this);        return -1;    }    d->inExec = true;    d->exit = false;    d->threadData->eventLoops.push(this);#if defined(QT_NO_EXCEPTIONS)    while (!d->exit)        processEvents(flags | WaitForMoreEvents | ProcessEventsFlag(QEventLoop::DeferredDeletion));#else    try {        while (!d->exit)            processEvents(flags | WaitForMoreEvents | ProcessEventsFlag(QEventLoop::DeferredDeletion));    } catch (...) {        qWarning("Qt has caught an exception thrown from an event handler. Throwing\n"                 "exceptions from an event handler is not supported in Qt. You must\n"                 "reimplement QApplication::notify() and catch all exceptions there.\n");        throw;    }#endif    QEventLoop *eventLoop = d->threadData->eventLoops.pop();    Q_ASSERT_X(eventLoop == this, "QEventLoop::exec()", "internal error");    Q_UNUSED(eventLoop); // --release warning    d->inExec = false;    return d->returnCode;}/*!    Process pending events that match \a flags for a maximum of \a    maxTime milliseconds, or until there are no more events to    process, whichever is shorter.    This function is especially useful if you have a long running    operation and want to show its progress without allowing user    input, i.e. by using the \l ExcludeUserInputEvents flag.    \bold{Notes:}    \list    \o This function does not process events continuously; it       returns after all available events are processed.    \o Specifying the \l WaitForMoreEvents flag makes no sense       and will be ignored.    \endlist*/void QEventLoop::processEvents(ProcessEventsFlags flags, int maxTime){    Q_D(QEventLoop);    if (!d->threadData->eventDispatcher)        return;    QTime start;    start.start();    while (processEvents(flags & ~WaitForMoreEvents)) {        if (start.elapsed() > maxTime)            break;    }}/*!    Tells the event loop to exit with a return code.    After this function has been called, the event loop returns from    the call to exec(). The exec() function returns \a returnCode.    By convention, a \a returnCode of 0 means success, and any non-zero    value indicates an error.    Note that unlike the C library function of the same name, this    function \e does return to the caller -- it is event processing that    stops.    \sa QCoreApplication::quit(), quit(), exec()*/void QEventLoop::exit(int returnCode){    Q_D(QEventLoop);    if (!d->threadData->eventDispatcher)        return;    d->returnCode = returnCode;    d->exit = true;    d->threadData->eventDispatcher->interrupt();}/*!    Returns true if the event loop is running; otherwise returns    false. The event loop is considered running from the time when    exec() is called until exit() is called.    \sa exec() exit() */bool QEventLoop::isRunning() const{    Q_D(const QEventLoop);    return !d->exit;}/*!    Wakes up the event loop.    \sa QAbstractEventDispatcher::wakeUp()*/void QEventLoop::wakeUp(){    Q_D(QEventLoop);    if (!d->threadData->eventDispatcher)        return;    d->threadData->eventDispatcher->wakeUp();}/*!    Tells the event loop to exit normally.    Same as exit(0).    \sa QCoreApplication::quit(), exit()*/void QEventLoop::quit(){ exit(0); }