How to use signals and slots in Slicer 3d?

Support
5

This example works for me:

class C(qt.QObject):
    received = qt.Signal(object)
    def __init__(self):
        super(C, self).__init__(None)
    def process(self, msg):
        self.received.emit(msg)

class D(qt.QObject):
    def __init__(self, sender):
        super(D, self).__init__(None)
        sender.received.connect(self.process)
    def process(self, msg):
        print("Processed this: "+repr(msg))

c = C()
d = D(c)
m = {'h': {'t': 's'}, 'c': {'e': 'i'}}

c.process(m)

(taken from these discussions: Custom Signal/Slots with PythonQt - #6 by ihnorton and PythonQt / Discussion / Help: Segmentation fault after emiting a signal)

However, normally there is no need to create Qt-based Python classes and define new signals and slots, as you can communicate via MRML nodes and VTK event observations:

What is your use case? What would you like to achieve with the custom signals/slots?