Compartment is meant to be a subview. Text compartment is really a label,
it doesn't have expand/collapse functionality, hence it has to be
implemented manually.
There is an option that requires the least amount of work though. Create a
compartment view (Node + DrawerStyle, possibly DescriptionStyle if
labels's text doesn't come from the semantics). Editpart of the
compartment will have a TextCompartmentEditPart as a child.
TextCompartmentEditPart will point to the compartment as its model.
Another option is decorating the compartment view with the label view.
Hopr this helps.