I have a huge application which is written in qt3. It contains a lot of UI, thread(s), QSocketDevice(s), queue(s), canvas

I know it is time to move on to QT4. Since our application is huge, how do I start?

I read the QT document which showing how to do porting. But, not much help. When I add qt3support in project file and compile it, there are too many errors. Besides, if i want to get ride of QT3 (without qt3support), how to do it?

Thanks.