Workflow of Creating Diagram Editors. The components and models used during GMF-based development are shown in Figure 2.3. Create GMF Project Develop Domain Model *.ecore Develop Graphical Definition Develop Mapping Model *.gmfmap Create Generator Model *.gmfgen Generate Diagram Plugin *.gmfgraph Develop Tooling Definition *.gmftool Figure 2.3 Workflow of using GMF for creating Diagram Editors, as shown in [14] As shown in this diagram, upon creating a GMF Project, we have to develop three different parts of the system. The Domain Model is the core of the system; it is actually the ecore model of the EMF. The two other parts, the Graphical Definition and the Tooling Definition, are the two parts of the GEF analyzed in the previous subsection. Given the domain model, GMF creates initial files for these two parts that have to be edited in order to provide the necessary information for the diagram editor. Upon creating the EMF and GEF parts, the most difficult step of this procedure is to develop the Mapping Model. This is, however, the main facility provided by GMF. Using the framework, the mapping model is created semi-automatically. Of course, the developer has to be very careful about the mapping provided by the system. Generally, simple objects and relations of the meta-model are safely automated. However, any slightly complex object (e.g. an edge with a label) is usually not correctly mapped. The Generator Model is the final model that has to be created. The model is initiated by the framework according to the mapping model. In short, the generator model is the mapping model including options for generating the plugin. Thus, any configurations such as file extensions of the plugin, context menus, etc. have to be defined in this model. The final step is to generate the diagram plugin. Although this is easily accomplished, any other improvements have to be made on generated code so the models of the GMF should be carefully designed.
