Add containment support with Sirius dedicated UI
Add the notion of container reference in the ecore and the textual grammar
use this notion in the Any AssetType of the building domain
Add support in Sirius for this containment:
- Containment links are displayed as nested boxes
- Creation in an Asset : add a container link (looks for the first compatible
container referencewhen creating the link) - Delete Asset : remove all related links (containment and non containment, so the model can be serialized)
- Drag'n drop : from the diagram to Asset, from Asset to Diagram, from Asset to Asset
- added icon in the palette
- updated building example (small reception)
Closes #243 (closed)
Current limitation: the AssetType must explicitly extend the Any AssetType
