The depth slider jumps 3 ticks when using mouse wheel

[EtlamGit]

You are creating the QSlider(Qt::Horizontal) in labelledslider.cpp

But you are not implementing an own event handler to monitor QWheelEvent. Therefore the slider implements the automatic mouse scroll wheel handling, which is 3 ticks for most people. Inside that handler you have to divide event->data by 120 to get the correct value.