zoom

void MainWindow::wheelEvent(QWheelEvent *event)
{
    qDebug() << "MyWidget::wheelEvent() INIT";
    int numDegrees = event->delta() / 8;
    int numSteps = numDegrees / 15;

    if (event->orientation() == Qt::Horizontal) {
        qDebug() << "MyWidget::wheelEvent() numSteps: " << numSteps;
    } else {
        qDebug() << "MyWidget::wheelEvent() numSteps: " << numSteps;
    }
    zoom = zoom + numSteps;
    qDebug() << "MyWidget::wheelEvent() zoom: " << zoom;
    ui->widget->zoomView(zoom);
    event->accept();
}