End-user composition of graphical user interfaces by composite pattern

Abstract

We present ComPat, an open source visual editor enabling end users to compose graphical user interfaces based on the composite pattern, a common software engineering design pattern: any widget or group of widgets is treated the same way as a single instance of the same type of widget. ComPat exploits a grid of rows and columns, where each cell, regulated by layout constraints, is populated either by direct import of widgets from a palette or by pattern application. In order to compose graphical user interfaces, any portion could be cut, copied, pasted, and treated as a single object thanks to the composite pattern, thus facilitating reusability. Any portion becomes a pattern that can be applied either by direct instantiation or by rewriting. ComPat automatically generates a Java Swing graphical user interface corresponding to the composition and stores its definition in a User Interface Description Language based on a XML Schema.