Chapter 9 TRANSFORMATIONAL DEVELOPMENT OF USER INTERFACESWITH GRAPH TRANS- FORMATIONS Quentin Limbourg and Jean Vanderdonckt IAG – School of Management, Université catholique de Louvain, Place des Doyens 1 – B-1348 Louvain-la-Neuve (Belgium) {limbourg,vanderdonckt}@isys.ucl.ac.be URL : http://www.isys.ucl.ac.be/bchi/members/{qli,jva} Tel : +32 10/47 {83 84, 85 25} – Fax : +32 10/47 83 24 Abstract In software engineering transformational development aims at developing software systems by transforming a coarse-grained specification to final code (or to a detailed specification) through a sequence of small transformation steps. Transformational development is known to bring benefits such as: cor- rectness-preserving of the development cycle, explicit mappings between de- velopment steps, reusability and reversibility of transformations. No piece of literature provides a systematic formal system applying transformational de- velopment to user interface engineering. To fill this gap, a methodology, called TOMATO, is described in three facets: 1) A development cycle is defined to outline possible transformations. 2) A language for supporting the methodol- ogy is presented relying on graph transformations, a mathematical system for expressing specifications and transformation rules. 3) A tool implementation, using a visual syntax, is illustrated. Keywords: Forward engineering, Graph grammar, Graph theory, Mapping problem, Pro- gram transformation, Reverse engineering, Transformational approach. 1. INTRODUCTION A state of the art [18] in the field of engineering methods of user inter- face shows that no method provides an integrated view of the abstractions needed to build a user interface along with an explicit mechanism to manipu- late these abstractions throughout a development cycle. More specifically, there is no general logical mechanism to incorporate and manipulate design knowledge in user interface creation tools [2,13] nor any system for relating 107 R. Jacob et al. (eds.), Computer-Aided Design of User Interfaces IV, 107–120. © 2005 Kluwer Academic Publishers. Printed in the Netherlands.