Qt 5.11 | Qt Core | C++ Classes | QBasicTimer

Qt 5.11.3 Reference Documentation

# QBasicTimer Class

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

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

- List of all members, including inherited members

## 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

The QBasicTimer class provides timer events for objects.

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().