How to emit signal through a few class objects in Qt?

Question

I have a few classes: Class A - highest class, Class B and Class C which are initialized in Class A constructor. In Class B constructor is initialized Class B1 and in Class C constructor is initialized Class C1. C1 object and B1 object does not see each other.

Every time I need to send signal from C1 class to B1 class, I connecting C1 and C, C and B, finally, B and B1. So every time my programm emitting a signal in C1 class object, it is sending to C class object then to B and then to B1. (On image) Is it a right Qt Way? Or there is a better way to do that?

Answer 1

You could add to class C an interface which returns C1 and a similar interface to class B, too. Then after creating classes C and B, class A could ask C1 and B1 and connect C1's signal to B1's slot.

Or, if you have lots of these kind of cases and you definitely don't want to expose classes C1 and B1 to A, you could create your own signaling mechanism. Some kind of "post office" where classes could register as receivers and to where classes could send messages. In this case, class B1 would register as a receiver and class C1 would send messages. C1 and B1 would know nothing about each other. The post office class would send C1's message to B1. This kind of "post office" class could also be implemented using Qt's signals and slots.