>I have implemented the observer pattern previously with the lists maintained internally by the objects involved, so removing the need to inherit from a particular class is a great improvement
That is what interfaces were made for. Create an interface for receiving a type of broadcast notification, and support it in the object types that you want to be able to receive such. Your notifier's lists of different types of listeners can become a single list of interfaces, and hence your notifier can broadcast to the interface methods without worrying about what types of objects it is dealing with, requiring them to inherit from particular ancestors, or having to do TMethod casts (which provide little flexibility anyway since target method parameters still have to conform to those of the broadcaster). Cheers, Carl _______________________________________________ Delphi mailing list [email protected] http://ns3.123.co.nz/mailman/listinfo/delphi
