From my experience QThread class can be somewhat confusing to use. Mostly due to how they work, not because they are hard, so here is a short explanation what and how to use threads in qT.
In the first place why to use threads? Threads are useful for heavy duty or computation expensive tasks that cause GUI to freeze. In example video compression takes a long time and is very CPU intensive. If that task is run on the same thread as you main GUI, in main application thread, program don’t receive events and operating system mark it as non responsive. Of course, if application is well written, after video compression GUI “unfreeze” and program works fine after that. This behaviour is not expected, because user don’t rally know if program works correctly or not. Read the rest of this entry »