src/corelib/kernel/qtimer.cpp

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/****************************************************************************
**
** Copyright (C) 1992-2006 Trolltech ASA. All rights reserved.
**
** This file is part of the QtCore module of the Qt Toolkit.
**
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** License version 2.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of
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** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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****************************************************************************/

#include "qtimer.h"
#include "qabstracteventdispatcher.h"
#include "qcoreapplication.h"

static const int INV_TIMER = -1;                // invalid timer id

QTimer::QTimer(QObject *parent)
    : QObject(parent), id(INV_TIMER), inter(0), del(0), single(0), nulltimer(0)
{
}


#ifdef QT3_SUPPORT

QTimer::QTimer(QObject *parent, const char *name)
    : QObject(parent), id(INV_TIMER), single(0), nulltimer(0)
{
    setObjectName(QString::fromAscii(name));
}
#endif

QTimer::~QTimer()
{
    if (id != INV_TIMER)                        // stop running timer
        stop();
}


void QTimer::start()
{
    if (id != INV_TIMER)                        // stop running timer
        stop();
    nulltimer = (!inter && single);
    id = QObject::startTimer(inter);
}

void QTimer::start(int msec)
{
    setInterval(msec);
    start();
}


#ifdef QT3_SUPPORT

int QTimer::start(int msec, bool sshot)
{
    if (id >=0 && nulltimer && !msec && sshot)
        return id;
    stop();
    setInterval(msec);
    setSingleShot(sshot);
    start();
    return timerId();
}
#endif


void QTimer::stop()
{
    if (id != INV_TIMER) {
        QObject::killTimer(id);
        id = INV_TIMER;
    }
}


void QTimer::timerEvent(QTimerEvent *e)
{
    if (e->timerId() == id) {
        if (single)
            stop();
        emit timeout();
    }
}

class QSingleShotTimer : public QObject
{
    Q_OBJECT
    int timerId;
public:
    ~QSingleShotTimer();
    QSingleShotTimer(int msec, QObject *r, const char * m);
signals:
    void timeout();
protected:
    void timerEvent(QTimerEvent *);
};

QSingleShotTimer::QSingleShotTimer(int msec, QObject *receiver, const char *member)
    : QObject(QAbstractEventDispatcher::instance())
{
    connect(this, SIGNAL(timeout()), receiver, member);
    timerId = startTimer(msec);
}

QSingleShotTimer::~QSingleShotTimer()
{
    if (timerId > 0)
        killTimer(timerId);
}

void QSingleShotTimer::timerEvent(QTimerEvent *)
{
    // need to kill the timer _before_ we emit timeout() in case the
    // slot connected to timeout calls processEvents()
    if (timerId > 0)
        killTimer(timerId);
    timerId = -1;
    emit timeout();
    delete this;
}

#include "qtimer.moc"

void QTimer::singleShot(int msec, QObject *receiver, const char *member)
{
    if (receiver && member)
        (void) new QSingleShotTimer(msec, receiver, member);
}

void QTimer::setInterval(int msec)
{
    inter = msec;
    if (id != INV_TIMER) {                        // create new timer
        QObject::killTimer(id);                        // restart timer
        id = QObject::startTimer(msec);
    }
}

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