I need to exec() a QApplication in a thread that is not main (my GUIs must be plugins that can be dynamically loaded and unloaded at runtime, so I have no access to the main thread). Does anyone know of a (relatively) painless way to hack around Qt's restriction against starting QApplication outside of main?
I'm developing in Linux with Qt4 in C++ using gcc4.3.4.
If you are using QThread then you already have normal Qt event loop and can just run exec() inside QThread::run() function. While you can't work with GUI objects outside of the main thread you still can interact with them through queued signal/slot connections. Maybe you can try to store pointer to the main thread QThread object and call QObject::moveToThread() to move your GUI objects to the main thread instead of moving QApplication into another thread.
I think it's not really good idea to try to go against toolkit with different kind of hacks and kluges.