Sequence Diagrams

[b-fein]

Is your feature request related to a problem?

I would like to be able to create sequence diagrams in Apollon.

Describe the solution you'd like

No other diagram type has the necessary components to misuse it as sequence diagram. Therefore, a new diagram type for sequence diagrams with its special components should be added.

Challenges

• The arrows can not not only attach to the middle of the activation boxes like in Activity Diagrams, but need to be placed on a specific location. At least the arrows placed at the topmost and bottommost locations, and the order for all incoming/outgoing arrows in between have to be kept when resizing the element.
• Split boxes for alt, opt, each capturing their own elements.
• How should the elements capture other elements?
  • The activation boxes on top of a lifeline.
  • Other activation boxes on top of activation boxes for self-calls.
  • Lifelines/method calls are entering and leaving the boxes for loop, alt, opt, … but other elements like arrows are fully contained within the box. Which elements should move with the box when the box is moved? I.e.,

Describe alternatives you've considered

None, as per description of the solution.

Additional context

The noted challenges seem to someone not familiar with Apollon (i.e., me) like there would be quite some restructuring needed to add sequence diagrams as a new diagram type. Possibly it’s even out-of-scope?