A layout abstraction for user-system interface

Abstract

The strict separation of the functionality of a system from the user-system interface is considered as a reasonable design principle. One promising way to enforce the separation is to supply the system designer with a "user interface toolkit", a set of integrated software tools for implementing the user-system interface. The difficulty resides in determining the "right" abstractions to be implemented by the toolkit. So far, there is no satisfactory answer to this problem, only propositions. Little has been proposed for object-oriented I/O as a toolkit facility. Yet, applications are currently bound to express I/O in terms of low level abstractions. As a result, they are in charge of tasks that are irrelevant to their functionality. In this paper, we propose the Box as a mechanism to permit applications to handle I/O in terms of their own abstractions and to be relieved from irrelevant tasks. The box mechanism has been implemented and integrated in a user interface toolkit.