Can a QGraphicsScene's mousePressEvent & mouseReleaseEvent be running simultaneously?

[blooglet]

That's not true, who told you that?

In Qt Creator's debugger, I can see how many threads are associated with the program. On several occasions, I saw that about 4 threads were running even though I hadn't used QThreads anywhere in my code. I sort of assumed that Qt programs always created multiple threads.

[wysota]

The word 'always' has a very specific meaning that is much different from the word 'sometimes'. It is almost important what the threads do.