QTimer
Module | Core |
---|---|
Include |
|
CMake |
|
QMake |
|
QTimer timer;
timer.start(1s);
co_await timer;
The QCoro frameworks allows co_await
ing on QTimer object. The
co-awaiting coroutine is suspended, until the timer finishes, that is until
QTimer::timeout()
signal is emitted.
The timer must be active. If the timer is not active (not started yet or already
finished) the co_await
expression will return immediately.
To make it work, include QCoroTimer
in your implementation.
#include <QCoroTimer>
#include <chrono>
using namespace std::chrono_literals;
QCoro::Task<> MyClass::pretendWork() {
// Creates and starts a QTimer that will tick every second
QTimer timer;
timer.setInterval(1s);
timer.start();
for (int i = 1; i <= 100; ++i) {
// Wait for the timer to tick
co_await timer;
// Update the progress bar value
mProgressBar->setValue(i);
// And repeat...
}
// ... until the for loop finishes.
}
QCoro::sleepFor()
A simple coroutine that will suspend for the specified time duration. Can be quite useful especially in unit-tests.
template<typename Rep, typename Period>
QCoro::Task<> QCoro::sleepFor(const std::chrono::duration<Rep, Period> &timeout);
QCoro::sleepUntil()
A simple coroutine that will suspend until the specified point in time. Can be useful for scheduling tasks.
template<typename Clock, typename Duration>
QCoro::Task< QCoro::sleepUntil(const std::chrono::time_point<Clock, Duration> &when);
Example:
const auto now = std::chrono::system_clock::now();
const auto tomorrow_time = std::chrono::system_clock::to_time_t(now + 86400s);
std::tm *gt = std::gmtime(&tomorrow_time);
gt.tm_hour = 0;
gt.tm_min = 0;
gt.tm_sec = 0;
const auto tomorrow_midnight = std::mktime(>);
co_await QCoro::sleepUntil(std::chrono::system_clock::from_time_t(tomorrow_midnight));