Sticking Nodes together

Question

Hello,

Is it possible to glue nodes permanently together?

My example: 

So the Systems and their belonging interfaces should stick togheter, like they are one node. So I'm able to draw the edges from one specific interface to another specific one.

Is this possible?

Thanks in advance! 

Answer 1

It's not possible to create such combined nodes but you can achieve the same appearance by adding multiple labels to a node. The label size should be set to 'Fit node width' and, of course, the border color to black. I suppose that the exact alignment will be a bit tricky, though.

Answer 2

But then I won't be able to draw the edges from one interface to a specific other?

Comments

Well, yes and no. When an edge is selected, you can move its end points to any location, either interactively by dragging the black square end markers or by specifying a port location in the properties view. Thus, you can move the ends of an edge to the area of its corresponding label.

On the other hand, this does not create a logical connection between the label and the edge, therefore, automatic layout will not maintain these assignments.

There is a mostly undocumented, advanced feature called Port Constraints in 'Tools -> Constraints' which can make it work for some layout algorithms, anyway. Please let me know if you need help on this.

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I have some difficulties figuring out how to add multiple labels and align them from top to bottom of the node. It seems that the Port Constrains feature works well.
Thanks for your help.

Btw: My intention is to write a little script which will transform dependencies, which are currently saved in some excel sheets, into a graphml file. The layout algorithmus would finish the job.