CODEWITHSUNDEEP
c++qtqmlqt-quickqt4.8
Dorin Botan
Dorin Botan

Reputation: 1378

Processing mouse wheel events in Qt4.8

In Qt5 it can be done in QML like this.

MouseArea {
    onWheel: {
        if (wheel.modifiers & Qt.ControlModifier) {
            adjustZoom(wheel.angleDelta.y / 120);
        }
    }
}

How to achieve the same in Qt4.8?

Upvotes: 0

Views: 712

Answers (1)

Dorin Botan
Dorin Botan

Reputation: 1378

Looks like I'm reinventing the bicycle but here is how it works for now.

I have a new QWidget that catches the wheelEvent and sends a new signal.

void WheelEventCarrier::wheelEvent(QWheelEvent *event)
{
    emit sendWheelEvent(event->delta()/120);
}

I define a new signal in QML and process it ibid.

signal wheelEvent(int delta)

onWheelEvent:
{
    if(delta > 0)
        tag_meas_mod.zoomIn(true);
    else
        tag_meas_mod.zoomOut(true);
}

I wrap my widget around all my UI and connect the two signals.

WheelEventCarrier carrier;
UI.setParent(&carrier);

QObject::connect(&carrier,
                     SIGNAL(sendWheelEvent(int)),
                     viewer.rootObject(),
                     SIGNAL(wheelEvent(int)));

carrier.show();

Hope you can point me to a better solution.

Upvotes: 1

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