Application won't quit until event loop quits

[caelestis]

I have webview and a function that waits until a page is loaded like this:

QEventLoop loop;
connect(this, SIGNAL(loadFinished(bool)), &loop, SLOT(quit()));
loop.exec();
while (frame->url().toString().compare(page.toString()) != 0) loop.exec();

QEventLoop loop;
connect(this, SIGNAL(loadFinished(bool)), &loop, SLOT(quit()));
loop.exec();
while (frame->url().toString().compare(page.toString()) != 0) loop.exec();

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but if the page is never loaded, and while the event loop is still in exec(), when qApp's quit() is called, the program will hang after the window closed. Shouldn't there be a way to wait for something and allow the application to exit at the same time?

[caelestis]

I think this is an easy question for someone more knowledgeable to answer. There must be some quick solution that I am not seeing.

[boudie]

You don't have to start your own eventloop.
Just connect to the loadFinished signal and do all your testing in that slot.

[caelestis]

Yes, but I need to wait for the page to finish loading so it would be like a blocking function. Right now I have some functions and when I load a web page I need to wait until the program finishes loading the page before I continue to the next step. I need to wait for new pages many times, so splitting my one function that loads many pages into many functions connected to each other is infeasible.

foo () {
load page
wait for page to load
do stuff to the page
load page
wait for page to oad
do stuff
...
}

foo () {
load page
wait for page to load
do stuff to the page
load page
wait for page to oad
do stuff
...
}

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[caelestis]

I still do not have a fix, can someone provide a solution?

[caelestis]

Anyone? Even a small hint?

[ChrisW67]

Some untested thoughts...

You could establish a QSemaphore as a member variable, with an initial count of 0. Create a slot to receive loadFinished() signals and execute QSemaphore::release() to release 1 resource (nothing else required). Between each request and the test (where you are looping now) use QSemaphore::acquire(1), which will block until a loadFinished() is received and a resource is released. You need to ensure a time out will apply if the page never returns.

You could, alternatively, busy wait on a boolean flag set by the loadFinished() receiving slot. Something like

m_finishedFlag = false;
... issue request
while (!m_finishedFlag)
  qApp->processEvents();

m_finishedFlag = false;
... issue request
while (!m_finishedFlag)
  qApp->processEvents();

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