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QBasicTimer Class

The QBasicTimer class provides timer events for objects. More...

Header: #include <QBasicTimer>
qmake: QT += core

Public Functions

QBasicTimer()
~QBasicTimer()
bool isActive() const
void start(int msec, QObject *object)
void start(int msec, Qt::TimerType timerType, QObject *obj)
void stop()
int timerId() const

Detailed Description

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 Wiggly example uses QBasicTimer to repaint a widget at regular intervals.

See also QTimer, QTimerEvent, QObject::timerEvent(), Timers, and Wiggly Example.

Member Function Documentation

QBasicTimer::QBasicTimer()

Contructs a basic timer.

See also start().

QBasicTimer::~QBasicTimer()

Destroys the basic timer.

bool QBasicTimer::isActive() const

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

See also start() and stop().

void QBasicTimer::start(int msec, QObject *object)

Starts (or restarts) the timer with a msec milliseconds timeout. The timer will be a Qt::CoarseTimer. See Qt::TimerType for information on the different timer types.

The given object will receive timer events.

See also stop(), isActive(), QObject::timerEvent(), and Qt::CoarseTimer.

void QBasicTimer::start(int msec, Qt::TimerType timerType, QObject *obj)

This is an overloaded function.

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

obj will receive timer events.

See also stop(), isActive(), QObject::timerEvent(), and Qt::TimerType.

void QBasicTimer::stop()

Stops the timer.

See also start() and isActive().

int QBasicTimer::timerId() const

Returns the timer's ID.

See also QTimerEvent::timerId().

© The Qt Company Ltd
Licensed under the GNU Free Documentation License, Version 1.3.
https://doc.qt.io/qt-5.13/qbasictimer.html