Activity Parameter without border

[tomte]

Hello,

I link from an Activity Diagram "MainAD" to an existing Activity sub-diagram "SubAD":

Activity Diagram "MainAD":
- Partition "Who"
- - Composite Element "Pointer"
- - - "Param1"
- - - "Param2"
- - - "ReturnParam"
- - ...
- ...

Activity sub-diagram "SubAD":
- in "InParam1"
- in "InParam2"
- Partition "Who"
- - Action "DoIt1"
- - Activity "SubActivity1"
- - Action "DoIt2"
- - ...
- ...
- out "OutParam"

First I learned: The linking Composite Element "Pointer" must be an Activity, not an Action:
I set the focus on the element "Pointer" > RightClick > NewDiagram > SelectCompositeDiagram
(This menu option "NewDiagram" is offered by Activity elements only, not by Action elements.)
The "eyeglass" icon appeared on the Composite Element "Pointer". And by clicking it the drilldown worked, ok.

Obviously "Param1" is to be passed to "InParam1" and "OutParam" in "SubAD" is to be bound to "ReturnParam" in "MainAD".

But how to show "InParam1", "InParam2" and "OutParam" on diagram "SubAD"?:

The only way was creating an (dummy) Activity "SubA", widening its border so nearly the whole print page was included, and then adding "InParam1", "InParam2" and "OutParam" to that huge border.

But the problem is: By adding this border-activity the diagram becomes instable. Trying to catch "DoIt1" and "DoIt2" with the mouse shifts the whole Activity instead (even after Z-Order > Send-Back).

A workaround might be: adding the border-activity at last an then set the focus on the (dummy) Activity "SubA" > Z-Order > Send-ToBottom.

Do you know a more stable way to show "InParam1", "InParam2" and "OutParam" on diagram "SubAD"?
I.e. without a (dummy) Activity "SubA"?

Thank you in advance - tomte

2015-10-25, Sparx EA 12.0.1215