TR-191: Towards Decomposable, Reusable Smalltalk Windows

Abstract

In Smalltalk, complex windows consisting of a large number of panes are often difficult to write and to modify. The present approach to window design tends to create very large models responsible for the application dependent behaviour of the entire window. Subparts of the windows cannot be extracted and allowed to retain any degree of their former behaviour.

We have expanded the model-view-controller (MVC) paradigm to allow for a more composite approach to window creation. We introduce “managers” to coordinate the communication between models and their views. Using these managers, individual panes or groups of panes can be given encapsulated behaviour that is highly independent of the context of their use, allowing them to be reused in a variety of applications. Decomposition makes window design both easier and faster.