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

This is a line drawn from a face on a Node outward. The terminator on the Node face is the root and the terminator on the other side of the line is the vine. Both terminators are generally referred to as the Stem ends.

A Stem may be decorated on either, both or neither end. A decoration consists of a graphic symbol such as an arrow or a circle or a fixed text Label such as the UML 0..1 multiplicity text. A graphic symbol may be combined with a text Decoration such as the Shlaer-Mellor open arrow head and c conditionality Label combination.

Identifiers

  1. ID + Connector Each Stem is uniquely numbered local to its Connector. The ID attribute is added since this is a -M association class which means that multiple instances of Stem may correspond to the same Connector–Stem Type pair.

  2. ID + Connector + Node + Face (superid) Super identifier is provided so that Anchored Stem subclass can enforce a constraint on Stem placement to avoid coincident Stems (see Anchored Stem).

  3. Node + Face + Root end Now two Stems may share the same Root end position on a Node Face. Same coincident Stem constraint as supported by identifier #2 above, but enforced at the point when the coordinates are resolved.

Attributes

ID

Distinguishes one Stem from another within the same Connector.

Type: Stem ID, based on Nominal

Face

The side of the Node where the Stem is anchored.

Type: Node Face :: [ Top | Bottom | Right | Left ]

Root end

The point on the attached Node face where the Stem root is anchored.

images/connector-subsystem/10_stem.png

Type: Position

Vine end

The point where the Stem vine ends away from the attached Node. See figure in Root end description.

Type: Position