QGraphicsSceneWheelEvent::delta being called when mouse wheel isn't used
I have a performance problem with a Qt widget application. Intel VTune Amplifier suggests the issue is with QGraphicsSceneWheelEvent::delta() being called along with QTimeLine::setCurveShape.
The application is reasonably simple. It receives data on a socket and creates a new row in a QAbstractTableModel if/when needed. Each cell could be coloured based on its content. I control this using a data() override within qstandarditrem. However, if remove my colouring etc and simple display text I'm still getting a performance hit ~ 20-60% Cpu.
So I'm interested to know why the QGraphicsWheelEvent::delta() method is being called when I'm not using the mouse at all. Also why/where is a QTimeLine::setCurveShape being called as I'm not directly calling this within my code?
I'm going to start a new thread as the subject is wrong. After configuring Intel VTune so it pointed at the Qt src directory it pointed me in the right direction.