R30 - modelint/flatland-model-diagram-editor GitHub Wiki

R30 / 1:1c

Diagram is rendered using exactly one Diagram Notation

Diagram Notation renders zero or one Diagram

---

When a Diagram is created, there may be a choice of multiple Notations that it can be displayed in. A class diagram, for example, could be displayed as Starr, xUML or Shlaer-Mellor notation. Each potential Diagram would mean the same thing, but the drawn notation would be different in each case.

A Diagram can use only a Notation that is defined for its Diagram Type. Since a Diagram Type must be supported by at least one Notation, there will always be at least one possible choice.

Only one Diagram is rendered at a time. This means that while, in theory, the same Diagram Notation could render multiple Diagrams and certainly does over time, during the runtime of the draw engine, a given Diagram Notation either is or isn’t the one that determines the look of a Diagram, thus the 1c multiplicity in this association.