Using the PAC-Amodeus model and design patterns to make interactive an existing object-oriented kernel

The paper presents an efficient way to provide a graphical interactive visualisation to a noninteractive existing object oriented application. Assuming that the initial application uses an `Abstract Factory´ pattern (GoF87) in order to create new objects, our aim is achieved by using the PAC-Amodeus model and extending the existing objects to create intermediate components, using object oriented techniques: inheritance, polymorphism and dynamic binding, using the `Proxy´ pattern (GoF207). Although our field of interest is physical and behavioural simulation, the techniques developed in the paper can be applied to any non-interactive object oriented existing kernel. We present a complete simulation example `Bugs life´ to illustrate the use of our method. Finally we point out the limits of our approach, and we suggest new directions for further work