Building error on enum of the QgsMapToolIentfy Class

Question

I am working on a project in c++/QT4.8.5 based on the api c++ 2.8.2 of QGis It is a stand alone application

I had to get information of a layer by clicking on it in the canvas

So I decide to use the class QgsMapToolIdentify ( i saw some sample in the book building mapping application with Qgis from Erik Westra )

here is my code :

mIdentify =new QgsMapToolIdentify(mpMapCanvas);
QList <struct IdentifyResult *> lResultList;

lResultList = mIdentify->identify(lCoord.x(),lCoord.y(), TopDownStopAtFirst, VectorLayer);

but when I want to build it i have an error on the enum value TopDownStopAtFirst and VectorLayer

the error message :

src/IHM/mainwindow.cpp:174:83: error: ‘VectorLayer’ was not declared in this scope lResultList = mIdentify->identify(lCoord.x(),lCoord.y(), TopDownStopAtFirst, VectorLayer);

and the same message for the TopDownStopAtFirst

I have included the header qgsmaptoolidentfy.h in main.cpp.

Answer 1

You have to specify the parent class name of the enum when using it outside its scope.

lResultList = mIdentify->identify(lCoord.x(),lCoord.y(), QgsMapToolIdentify::TopDownStopAtFirst, QgsMapToolIdentify::VectorLayer);

But this is really more of a general C++ issue than GIS specific. If you run into more of these, please ask them on https://stackoverflow.com/ .

Answer 2

in fact there is another error here is the code working :

mIdentify =new QgsMapToolIdentify(mpMapCanvas);
mIdentify->activate();
QList < QgsMapToolIdentify::IdentifyResult > lResultList;
lResultList.append(mIdentify->identify(lCoord.x(),lCoord.y(),QgsMapToolIdentify::TopDownStopAtFirst, QgsMapToolIdentify::VectorLayer));

qDebug() << "size identify Qlist =" << lResultList.size();

the qdebug show the number of element in the qlist each time the function has been called. In my application, the function is called when a subfunction is activated and then when I left click on the map i have a result