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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.

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