Problem With QTest::qSleep()

[Percipient]

Inside a loop that is filling a listWidget with potentially millions of items I want to check if a cancel button has been pressed:

@void TextBox::on_fillButton_clicked() {
QStringList lines;
for (int i=0; i < 100000; i++) {
if (i % 1000 == 0) {
QTest::qWait(0);
if (actionCancelled) {
actionCancelled = false;
return;
}
}
std::ostringstream ostr;
ostr << "line " << i;
lines << ostr.str().c_str();
}

ui->listWidget->addItems(lines);

}@

My hope was that the call to QTest::qWait() would allow the click on the Cancel button to be detected and its slot method called:

@void TextBox::on_cancelButton_clicked() {
actionCancelled = true;
}@

But it won't run because QTest::qWait() is implemented using QTest::qSleep(), and it seems to be an undefined reference:

@undefined reference to `QTest::qSleep(int)'@

Looking in qtestcase.h I see that QTest::qSleep() is defined like this:

@Q_TESTLIB_EXPORT void qSleep(int ms);@

Poking around the web I see that QTest::qSleep() is implemented on Windows using its Sleep function, so maybe the association between QTest::qSleep() and the Windows Sleep function is failing to be made, somehow.

So I guess the questions are:

If it's pilot error, what am I doing wrong?

If it's a problem with my installation, how do I fix it?

If I'm approaching this the wrong way, what approach should I take?

--Percy

[lgeyer]

"QCoreApplication::processEvents()":http://qt-project.org/doc/qt-4.8/qcoreapplication.html#processEvents is what you are looking for.

If you want to use functionality of the QtTest library you will have to add <code>QT += testlib</code> to your <code>.pro</code> file.