QChart horizontal only zoom?

[martonmiklos]

I am working on a digital waveform display where only the horizontal zooming makes sense. Is there any way to restrict the zoom to the horizontal scale. I have seen the
zoomIn(const QRectF &) member, but I would like to avoid the continous rectangle calculation.

[martonmiklos]

For the posterity:

void ZoomableChartView::wheelEvent(QWheelEvent *event)
{
    if (event->angleDelta().y() > 0) {
        zoomX(2, event->pos().x() - chart()->plotArea().x());
        qWarning() << chart()->plotArea();
    } else if (event->angleDelta().y() < 0) {
        zoomX(0.9, event->pos().x() - chart()->plotArea().x());
    }
}

void ZoomableChartView::zoomX(qreal factor, qreal xcenter)
{
    QRectF rect = chart()->plotArea();
    qreal widthOriginal = rect.width();
    rect.setWidth(widthOriginal / factor);
    qreal centerScale = (xcenter / widthOriginal);

    qreal leftOffset = (xcenter - (rect.width() * centerScale) );

    rect.moveLeft(rect.x() + leftOffset);
    chart()->zoomIn(rect);
}