How do i send a signal with parameters from QML to cpp code

maxpayne

Hi,

I would appreciate some hints to this problem that I'm facing. I am creating dynamic components and would like to send some data back to the cpp code.

(this is just pseudo code)
in main.qml :

@Rectangle {
id: container

    MyComponent {
             id: mycomp
         }

}
@
in "MyComponent.qml"

@Item {
id: myitem

var component = Qt.createComponent("Wheel.qml"); //dynamic objects...
 var object = component.createObject(myitem);

}@

finally "Wheel.qml"

@ Rectangle {
id:myWheel
Component.onCompleted: {
//SEND SOME DATA (x,y) TO CPP CODE
}
}@

potential cpp code:
@view->setSource(QUrl("qrc:/QML/main.qml"));
QGraphicsObject *object = view->rootObject();
??@

I am not sure how the how to send data as a signal from wheel component to cpp code. Any ideas?

Aleskey78

"Using QML Bindings in C++ Applications":http://doc.trolltech.com/4.7-snapshot/qtbinding.html#calling-functions

maxpayne

Thanks!

Actually, it was this document that helped:

http://doc.qt.nokia.com/latest/qml-extending-types.html#connecting-signals-to-methods-and-other-signals

For dynamic objects use the connect call...

So in "Wheel.qml"
@Rectangle {
id:myWheel
Component.onCompleted: {
//SEND SOME DATA (x,y) TO CPP CODE
mySignal(x,y)
}
}@

in “MyComponent.qml”

@
//the syntax is interesting here..you simply connect the signals but don't specify the arguments..
object.mySignal.connect(myitem.anothersignal); @

finally in cpp:

@QGraphicsObject *object = view->rootObject();
QObject::connect(object,SIGNAL(anothersignal(int,int)),this, SLOT(executeKClosure(int,int)));
@

Aleskey78

no cpp detected..., only JS

maxpayne

I've updated my reply...the js code is crucial to propagate the data to the cpp code.