Developing a DSL Graphical Notation - Eclipse Modeling Project: A Domain-Specific Language Toolkit - page 72

Table 4-2 Mindmap Topic Mapping

Element Property Value

Mapping

Top Node Reference Containment Feature Map.elements : MapElement

Node Mapping Element Topic -> MapElement

Diagram Node Node Topic (TopicFigure)

Tool Creation Tool Topic

Feature Label Mapping Diagram Label Diagram Label TopicName

Features MapElement.name : EString

Below the Top Node Reference mapping is the Node Mapping for the
Topic class itself. The Topic class, which is a subclass of MapElement , is used
for the node's Element . The Topic node from our mindmap.gmfgraph is used
for the Diagram Node , which we see references the TopicFigure from the
Figure Gallery . Finally, the Node requires a Tool , so we select the Topic
Creation Tool from our palette defined in our mindmap.gmftool model.
Note that the Appearance Style and Context Menu properties are left blank
because GMF has not yet implemented them.
The Topic displays its name using a label, which is defined in the child
Feature Label Mapping element. The Diagram Label property is selected
to the TopicName label in our graphical definition and displays the value of the
Topic 's name:EString attribute. Both the Edit and View Method properties
are set to the default MESSAGE_FORMAT value, meaning that the Java
MessageFormat class provides the underlying implementation for parsing, edit-
ing, and displaying our label. In the case of our Topic label, a single attribute is
displayed, with no other characters required.
With the node mapping complete, let's look at the subtopics link mapping.
In our domain model, Topic s are related to other “sub” Topic s using the
subtopics reference. Simple references such as this are straightforward to map in
GMF because we only need to set our Target Feature property to this refer-
ence in our domain model, as seen in Table 4-3. Our next link mapping discusses
the remaining Domain meta information properties. The Diagram Link
and Tool properties are set as you would expect, to the TopicSubtopics
Connection from our graphical definition, and to the TopicSubtopics
Creation Tool in our tooling definition, respectively.