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39
40#ifndef QTESTSUPPORT_CORE_H
41#define QTESTSUPPORT_CORE_H
42
43#include <QtCore/qcoreapplication.h>
44#include <QtCore/qdeadlinetimer.h>
45#include <QtCore/qthread.h>
46
47QT_BEGIN_NAMESPACE
48
49namespace QTest {
50
51Q_CORE_EXPORT void qSleep(int ms);
52
53template <typename Functor>
54[[nodiscard]] static bool qWaitFor(Functor predicate, int timeout = 5000)
55{
56 // We should not spin the event loop in case the predicate is already true,
57 // otherwise we might send new events that invalidate the predicate.
58 if (predicate())
59 return true;
60
61 // qWait() is expected to spin the event loop, even when called with a small
62 // timeout like 1ms, so we we can't use a simple while-loop here based on
63 // the deadline timer not having timed out. Use do-while instead.
64
65 int remaining = timeout;
66 QDeadlineTimer deadline(remaining, Qt::PreciseTimer);
67
68 do {
69 // We explicitly do not pass the remaining time to processEvents, as
70 // that would keep spinning processEvents for the whole duration if
71 // new events were posted as part of processing events, and we need
72 // to return back to this function to check the predicate between
73 // each pass of processEvents. Our own timer will take care of the
74 // timeout.
75 QCoreApplication::processEvents(QEventLoop::AllEvents);
76 QCoreApplication::sendPostedEvents(nullptr, QEvent::DeferredDelete);
77
78 if (predicate())
79 return true;
80
81 remaining = int(deadline.remainingTime());
82 if (remaining > 0)
83 qSleep(qMin(10, remaining));
84 remaining = int(deadline.remainingTime());
85 } while (remaining > 0);
86
87 return predicate(); // Last chance
88}
89
90Q_CORE_EXPORT void qWait(int ms);
91
92} // namespace QTest
93
94QT_END_NAMESPACE
95
96#endif
97