Back to Qt.io
Contact Us Blog Download Qt

QBasicTimer Class

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

Header: #include <QBasicTimer>
CMake: find_package(Qt6 REQUIRED COMPONENTS Core)
target_link_libraries(mytarget PRIVATE Qt6::Core)
qmake: QT += core

Public Functions

QBasicTimer()
QBasicTimer(QBasicTimer &&other)
~QBasicTimer()
bool isActive() const
(since 6.5) void start(std::chrono::milliseconds duration, QObject *object)
(since 6.5) void start(std::chrono::milliseconds duration, Qt::TimerType timerType, QObject *obj)
void stop()
void swap(QBasicTimer &other)
int timerId() const
QBasicTimer &operator=(QBasicTimer &&other)
void swap(QBasicTimer &lhs, QBasicTimer &rhs)

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().

Objects of this class cannot be copied, but can be moved, so you can maintain a list of basic timers by holding them in container that supports move-only types, e.g. std::vector.

See also QTimer, QTimerEvent, QObject::timerEvent(), Timers, and Affine Transformations.

Member Function Documentation

[constexpr noexcept] QBasicTimer::QBasicTimer()

Constructs a basic timer.

See also start().

[noexcept] QBasicTimer::QBasicTimer(QBasicTimer &&other)

Move-constructs a basic timer from other, which is left inactive.

See also isActive() and swap().

[noexcept] QBasicTimer::~QBasicTimer()

Destroys the basic timer.

[noexcept] bool QBasicTimer::isActive() const

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

See also start() and stop().

[since 6.5] void QBasicTimer::start(std::chrono::milliseconds duration, QObject *object)

Starts (or restarts) the timer with a duration 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.

This function was introduced in Qt 6.5.

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

[since 6.5] void QBasicTimer::start(std::chrono::milliseconds duration, Qt::TimerType timerType, QObject *obj)

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

obj will receive timer events.

This function was introduced in Qt 6.5.

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

void QBasicTimer::stop()

Stops the timer.

See also start() and isActive().

[noexcept] void QBasicTimer::swap(QBasicTimer &other)

Swaps the timer other with this timer. This operation is very fast and never fails.

[noexcept] int QBasicTimer::timerId() const

Returns the timer's ID.

See also QTimerEvent::timerId().

[noexcept] QBasicTimer &QBasicTimer::operator=(QBasicTimer &&other)

Move-assigns other to this basic timer. The timer previously represented by this basic timer is stopped. other is left as inactive.

See also stop(), isActive(), and swap().

Related Non-Members

[noexcept] void swap(QBasicTimer &lhs, QBasicTimer &rhs)

Swaps the timer lhs with rhs. This operation is very fast and never fails.

© 2024 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners. The documentation provided herein is licensed under the terms of the GNU Free Documentation License version 1.3 as published by the Free Software Foundation. Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners.