Contrary to my original intention of working this week on code generation and the sample application, I have been doing some improvements in the graphical visualization of UML models in EclipseGraphviz. EclipseGraphviz (a spin-off of the TextUML Toolkit) is an open source component (EPL) that integrates Graphviz into Eclipse, and among other things, can generate UML class diagrams from Eclipse UML2 models on the fly.
After fixing a couple of bugs, I decided to add a preference page to give some level of control over the way the diagrams are laid out. Here is what it looks like:
You can now turn on or off several adornments such as association end names, multiplicities and membership. For example, this diagram was rendered using the options shown above:
Whereas the following one was rendered for the same model while having only the “Create constraints for association navigability” option checked:
As you can see, enabling constraints based on association navigability can significantly alter the diagram layout. One good reason for enabling that option is to avoid diagrams that grow too much horizontally (as Graphviz will put all nodes of the same rank on the same row), but I personally prefer the former layout.
Side note: I considered dropping the graphical visualization feature altogether for 1.0, as I see it as just a nice to have, and am not totally happy with the quality of the diagrams generated by Graphviz. But every bit of feedback I got for the TextUML Toolkit was that the graphical visualization was really nice, so I changed my mind. But unless serious bugs are found in this area, I have no plans of touching the EclipseGraphviz code again until after I complete the 30-day challenge.
Side note #2: I expanded the FAQ to cover the issue of notation choice and the role of EclipseGraphviz in the TextUML Toolkit.
