Using QNetworkAccessManager::authenticationRequired with own input widget / asynchronously

Question

I'm currently developing a browser with Qt which has a vim-like input bar:

This is basically just a QHBoxLayout with a QLineEdit and some QLabels in it.

Now I'd like to handle HTTP authentication. The usual thing I see in other projects is opening a modal QDialog and then calling exec() on it inside the slot connected to the authenticationRequired signal.

Now I'd like to use the same statusbar to ask the user for authentication information, i.e. displaying some prompt and then using the QLineEdit to enter the information.

My problem is the authenticationRequired slot blocks, I can't simply continue to run in the mainloop and continue the request with authentication information added when the user is done.

I've thought about two solutions:

• Implementing some function which gets the values from the statusbar while calling QCoreApplication::processEvents while there's no reply from the user yet. However I'm not sure if that's a good idea, and if the application will hog a lot of CPU until I'm back to the real eventloop.

• Somehow saving and aborting the request, asking the user for authentication, and then re-creating the request as soon as the authentication information is added. But it seems I can't simply clone a QNetworkReply and then call abort() on the original reply and resume it later.

Looking at how QDialog::exec() is implemented it seems they create a new QEventLoop with an undocumented value of QEventLoop::DialogExec passed. I wonder if I could do the same, but then I'm not sure how I'd quit the event loop once the user input is there.

Which of these ideas sounds like the most sane one?

Answer 1

You can just use a QEventLoop without any special undocumented values. Instead you'll have something like:

QEventLoop loop;
connect(editBox, SIGNAL(finishedEditing()), &loop, SLOT(quit()));
loop.exec();

And that will start a new event loop that blocks, waiting for your input (without hogging as much cpu as processEvents)