I'm updating an existing BOOPSI gadget to support the OM_NOTIFY method on the GA_Selected attribute. The idea is that the gadget (a checkbox kind) can act as a "master" gadget that sets the value of its subordinate gadgets. Thus, when the master's GA_Selected is set to TRUE/FALSE, the subordinate gadgets will receive an OM_NOTIFY to set their value to that of the master. For this to work, the master checkbox adds the subordinate checkboxes to its broadcast list via OM_ADDMEMBER.
In the "rkrmmodelclass.c" example in the Amiga Dev Wiki, the actual execution of the OM_NOTIFY method is delegated to the superclass (model.class), which informs the gadgets on the rkrmmodel.class's broadcast list.
OK, that's the model class kind. But what I'm not sure about is how gadgetclass subclasses are supposed to act. Should the OM_NOTIFY be handled by my checkbox gadget, or should I pass it on to gadgetclass by calling IDoSuperMethod()?