Connect QML signal to C++11 lambda slot (Qt 5)

Question

Connecting a QML signal to a regular C++ slot is easy:

// QML
Rectangle { signal foo(); }

// C++ old-style
QObject::connect(some_qml_container, SIGNAL(foo()         


        

Answer 1

Lambdas etc only work with new syntax. If you can't find a way to give QML signal as a pointer, then I think it is not directly possible.

If so, you have a workaround: create a dummy signal-routing QObject subclass, which only has signals, one for every QML signal you need to route. Then connect QML signals to corresponding signals of an instance of this dummy class, using the old connect syntax.

Now you have C++ signals you can use with the new syntax, and connect to lambdas.

The class could also have a helper method, to automate connections from QML to signals of the class, which would utilize QMetaObject reflection mechanisms and a suitable signal naming scheme, using same principle as QMetaObject::connectSlotsByName uses. Alternatively you can just hard-code the QML-router signal connections but still hide them inside a method of the router class.

Untested...