This article consists only of a collection of slides from the author's conference presentation.

This paper describes an approach to object-oriented interface design that goes beyond mere object decomposition. In our user interface management system we use logic and filters to declaratively specify and control a space of ways that objects may be composed to create interfaces. A filter is a package of constraints and associated typed objects that express the relationship of data and representation objects.Conceptually our system is completely based on constraints. Filters provide the high bandwidth constraints to maintain the components of the direct-manipulation interface while the logic forms the low bandwidth constraints to combine and provide communication between these components. The use of Horn-clause logic to compose separate interface objects facilitates both the distribution of computation onto multiple processors and the generation of multiple views of data. Intelligent backtracking implemented in the logic allows for user- and system-initiated undo operations to correct errors and/or try alternative approaches to a problem. We illustrate the power and flexibility of this approach by describing a floor layout and design system.