qtbase/src/corelib/kernel/qbasictimer.cpp

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#include "qbasictimer.h"
#include "qabstracteventdispatcher.h"

QT_BEGIN_NAMESPACE

/*!
    \class QBasicTimer
    \brief The QBasicTimer class provides timer events for objects.

    \ingroup events

    This is a fast, lightweight, and low-level class used by Qt
    internally. We recommend using the higher-level QTimer class
    rather than this class if you want to use timers in your
    applications. Note that this timer is a repeating timer that
    will send subsequent timer events unless the stop() function is called.

    To use this class, create a QBasicTimer, and call its start()
    function with a timeout interval and with a pointer to a QObject
    subclass. When the timer times out it will send a timer event to
    the QObject subclass. The timer can be stopped at any time using
    stop(). isActive() returns true for a timer that is running;
    i.e. it has been started, has not reached the timeout time, and
    has not been stopped. The timer's ID can be retrieved using
    timerId().

    The \l{widgets/wiggly}{Wiggly} example uses QBasicTimer to repaint
    a widget at regular intervals.

    \sa QTimer, QTimerEvent, QObject::timerEvent(), Timers, {Wiggly Example}
*/


/*!
    \fn QBasicTimer::QBasicTimer()

    Contructs a basic timer.

    \sa start()
*/
/*!
    \fn QBasicTimer::~QBasicTimer()

    Destroys the basic timer.
*/

/*!
    \fn bool QBasicTimer::isActive() const

    Returns true if the timer is running and has not been stopped; otherwise
    returns false.

    \sa start() stop()
*/

/*!
    \fn int QBasicTimer::timerId() const

    Returns the timer's ID.

    \sa QTimerEvent::timerId()
*/

/*!
    \fn void QBasicTimer::start(int msec, QObject *object)

    Starts (or restarts) the timer with a \a msec milliseconds
    timeout.

    The given \a object will receive timer events.

    \sa stop() isActive() QObject::timerEvent()
 */
void QBasicTimer::start(int msec, QObject *obj)
{
   stop();
   if (obj)
       id = obj->startTimer(msec);
}

/*!
    \overload

    Starts (or restarts) the timer with a \a msec milliseconds timeout and the
    given \a timerType. See Qt::TimerType for information on the different
    timer types.

    The given \a object will receive timer events.

    \sa stop() isActive() QObject::timerEvent() Qt::TimerType
 */
void QBasicTimer::start(int msec, Qt::TimerType timerType, QObject *obj)
{
    stop();
    if (obj)
        id = obj->startTimer(msec, timerType);
}

/*!
    Stops the timer.

    \sa start() isActive()
*/
void QBasicTimer::stop()
{
    if (id) {
        QAbstractEventDispatcher *eventDispatcher = QAbstractEventDispatcher::instance();
        if (eventDispatcher)
            eventDispatcher->unregisterTimer(id);
    }
    id = 0;
}

QT_END_NAMESPACE