//! [0]
void MyWidget::wheelEvent(QWheelEvent *event)
{
    int numDegrees = event->delta() / 8;
    int numSteps = numDegrees / 15;

    if (event->orientation() == Qt::Horizontal) {
        scrollHorizontally(numSteps);
    } else {
        scrollVertically(numSteps);
    }
    event->accept();
}
//! [0]