Graphical animation of object-oriented software designs (abstract)

We have built an extension to a prototype CASE tool calledESPEX, that makes it possible to execute graphically WassermansObject-Oriented Structured Design (OOSD) notation. The tool itselfis implemented in the Smalltalk 80 programming environment. Thetool contains a window-based menu-driven graph editor and anintegrated graph simulator with animation support. Animation meansthat the movements of data items and messages between objects arevisualized on a workstation display. We have implemented simulation for object instances. We areusing moving tokens with data values attached on top of them.Tokens flow from objects to other objects, carrying the essentialdata with them. The moving tokens indicate clearly the active partsof the model, while the data values also make it possible tovisualize the actual computations that take place in the objects.Another advantage of moving tokens is that it is possible to attachtime stamps to tokens. With the help of the time stamps it ispossible to simulate experimenting with animation techniques fordynamic creation and deletion of objects. We model objects hierarchically, so that an object can becomposed of other lower level objects. At the lowest level objectsare described with predicate/transition Petri nets, and thecomputations with IPTBS Meta-IV, Smalltalk-80, or C. The work presented demonstrates that it is possible and feasibleto animate object-oriented design notation using a token movingapproach. However, there is still much work to be done on theanimation of dynamic instantiations and deletion of objects. Webelieve that graphical animation tools are the enabling technologyfor teamwork and for conceptual communication in the futureconcurrent engineering working environments. The work presented in this demo was carried out in the IPTESproject. IPTBS is partially funded by the European Communitiesunder the ESPRIT programme.