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Recursive Diagram Editors [message #806334]

Fri, 24 February 2012 16:04

Eclipse User

Hello GMF experts!

I'm new to GMF and I have a question on creating a diagram editor with the following model.

For example:

1. Diagram Root -> contains Record and RecordGroup
2. A Record has Elements.
3. A RecordGroup has Elements.
4. An Element(abstract) can be a DataElement or a GroupElement.
5. In my ecore, the DataElement is the "leaf" whereas the GroupElement has reference to the RecordGroup but the relationship is not a containment (i.e. containment=false).

GOAL:
My goal is to create a graphical editor that represents the Record in a box that has elements in separate boxes (can be a DataElement or GroupElement). For DataElement, since this is a leaf, I don't have problems. But if it is a GroupElement, I must be able to put another box inside which represents the RecordGroup which in turn can contain Elements and so on...

In my gmfmap file, the top node is Record and I have 2 ChildReferences (DataElement & GroupElement) I added another ChildReference to GroupElement pointing to RecordGroup but GMF won't let me and returns this error.

"... 'Containment Feature' must be owned by 'Domain Meta Element' or its super type of this reference parent Node Mapping mapping.gmfmap /<some package..>/model..."

Is there a way to get around this problem? Or is it really the limitation of GMF to only have a recursive heirarchy using objects having containment references in a model.

Appreciate the help! Smile

Re: Recursive Diagram Editors [message #808326 is a reply to message #806334]

Mon, 27 February 2012 11:59

Eclipse User

Hello,

I recently answered in details why GMF asks for matching containment in this thread.

I guess that the same 3 (actually 2 for right now) alternatives are applicable to your use case - in brief, you may either ignore the warning and fix the compilation problems, or implement the derive references that follows graphical containment and use those derived refs for GMF-map input model.

Hope that helps,
Regards,
Michael "Borlander" Golubev
at Montages Think Tank, Prague, Czech Republic
Montages AG, Zürich, Switzerland

Re: Recursive Diagram Editors [message #808416 is a reply to message #808326]

Mon, 27 February 2012 14:10

Eclipse User

Thanks Michael for the response! Smile

I'm thinking to go with alternative #1... but also I'm interesed to know how to do alternative #2.

Do you have an refernces/examples on how to do alternative #2?

Sorry again, as I'm quite new to all of this.

Thanks!

Re: Recursive Diagram Editors [message #808489 is a reply to message #808416]

Mon, 27 February 2012 16:02

Eclipse User

Well, what I meant as an alternative 2 is just:

a) Answer the question "for given GroupElement how can I find the only corresponding RecordGroup which actually contains the Element's that shuld be shown at the diagram inside the GroupElement' node"
b) Add the

derived ref Element[*] diagramElements;

into the class GroupElement
c) In the EMF-generated code implement your answer for a) into the GroupElementImpl#getDiagramElements().
Note that if your logic is just "choose or create some RecordGroup and use its elements" than you may just return the results of the RecordGroup#getElements by reference, it will ensure that adding some element into this list will put the Element into some correct place.
d) use this new derived feature for diagram definition
As I have already mentioned, you will have the warning about non-containment on step d) anyway, because we can't define derived containments in the EMF.

Regards,
Michael

Re: Recursive Diagram Editors [message #808518 is a reply to message #808489]

Mon, 27 February 2012 16:46

Eclipse User

Ok, I will try that! Thanks again!

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