A new event dispatch strategy to eliminate dispatch “glue”

In statically typed object-oriented languages such as Java, GUI event handling is traditionally handled through listener interfaces or similar types of polymorphic delegation. In the case of events that pass information about their source to the handling method, the programmer is required to perform runtime type checks to determine the true types of the components involved. This produces poorly designed code that contains a second layer of hand-written type-based dispatch before events can actually be handled. In this paper we present an alternative approach that builds this second dispatch layer into the underlying framework. The approach uses run-time reflection and overload resolution to automatically distinguish events based on method argument types, and to implicitly bind them to the event publishers. This approach combines the type safety of a statically typed language with the run-time flexibility of modern dynamic languages and enhances the readability of event handling code.