Design and Implementation of an Editor for Active Object/Behavior Diagrams

This thesis presents the design and the implementation of an editor for modeling Active Object/behavior Diagrams (AOBD editor). AOBD is a graphical language for the conceptual design of active object-oriented databases. It consists of Object/Behavior Diagrams, of Situation Diagrams, and of Activation Diagrams. AOBD supports the design of object structures as well as the design of objects? passive and active behavior. The AOBD editor is implemented in the programming environment VisualWorks, which uses Smalltalk-80 as scripting language, using the DoME (Domain Modeling Environment) toolset for the construction of graphical editors. The object-oriented database system GemStone and the BOSS (Binary Object Streaming Service) mechanism of VisualWorks are used to store diagrams either in a database or into a file. The AOBD editor?s basic architecture consists of three layers. Object on layer 1 the DoME Layer, are used for displaying and manipulating the objects representing the conceptual database schema. Since object on the DoME layer are disposed whenever a diagram is closed, objects on layer 2, the Graphical Layer, store their position, their size, and their appearance. Whenever a diagram is opened, persistent object of the graphical layer are used to create DoME object. Object on layer 3, the Semantic Layer, represent the conceptual database schema, which is created incrementally by drawing the diagrams. The AOBD editor maintains consistency throughout the diagrams by a restrictive user interface that allows only valid graphical operations and by the lexical analysis of textual expressions.