@xumuk As said earlier it is a limitation. But if you still need it you should have a look at the 2nd and 3rd paragraph in the link which I posted earlier. Basically you will have to do this:
QQuickWidget *wd = new QQuickWidget(this);
wd->setAttribute(Qt::WA_AlwaysStackOnTop);
wd->setClearColor(Qt::transparent);
//and the opacity can be set in QML istelf for eg. for a Rectangle
Rectangle {
width: 300
height: 300
color: "green"
opacity: 0.5
}
If you load this QML in the QQuickWIdget and put a QWidget in background it should be visible.
