I have some trouble understanding how to use the "open sub-diagram" action (from the context menu) with sub activities. I am almost convinced it's a bug, but maybe I am just not understanding how to use it correctly.
1. I create two activity diagrams under "Model", lets name them FooActivity and BarActivity (with FooActivityDiagram and BarActivityDiagram as owned elements under them)
2. I open FooActivityDiagram and drag BarActivity from the model explorer onto the canvas (BarActivity appears as an action with the little o-o icon on the canvas. In the properties I can see it has "subjectivity: BarActivity". In the model explorer I can see the action is owned by BarActivity
3. I right click the action view in the canvas and select "Open Sub-Diagram" from the context menu
Expected behaviour: It should take me to BarActivityDiagram
Actual Behaviour: Message pops up "No sub-diagram in the selected element"
Is it a bug? Am I doing something wrong here?
Note as a workaround I kind of can make it work if I create an action from the toolbox (instead of dragging the BarActivity from the model explorer) and then later making BarActivity an owned element of this new action (and manually selecting BarActivity as the subjectivity of that action). But this seems oddly cumbersome.