Bug 355641

Description Robert Brodt 2011-08-24 06:09:43 EDT

To reproduce the problem, create a new diagram with two pools, and then create two message links between these two pools. Both links will be created in the same location, connecting the central points of the two pools.

This obviously does not permit the use of collaboration diagrams between two abstract participants. It also causes problems where one abstract participant (pool) is being connected to send/receive tasks in another pool, as the links all converge on a point on the abstract participant.


Brian Fitzpatrick added a comment - 27/Jun/11 4:18 PM

The workaround in this case is to do the following:

1. Use the Select tool in the palette.
2. Select the top-most Message Flow connection in the diagram.
3. Locate the center-most circular handle on the connection line.
4. Click and drag that handle to the right, left, top, or bottom to change the path slightly.

You can now select both Message Flows and affect their positions and properties independently.

Do we need a different solution than this?


Gary Brown added a comment - 28/Jun/11 4:07 AM

The problem with this approach is that the arrow heads for each message flow end up pointing left or right at the centre of the destination pool.


Brian Fitzpatrick added a comment - 28/Jun/11 11:36 AM

Gary, I'm afraid I don't quite understand why that's a problem. No matter what solution we choose I expect it's going to require the line to bend and the endpoints be slightly off-center. I don't believe this makes it unreadable or unintelligible at all.


Robert (Bob) Brodt added a comment - 28/Jun/11 11:52 AM

Gary, if you get a chance can you look at this again? I think what happened is that Innar fixed this since you reported the issue. Check out https://github.com/imeikas/BPMN2-Editor-for-Eclipse/commit/74c9c818ee32b43478724dbdd0075166f33c41cb

The Send/Receive connections are now anchored to their respective tasks and Message Flows between pools are anchored at the edges of the pools, so the arrow heads/tails are visible. I think we can live with this unless we want to implement an auto layout policy for message flows between pools so that each line is evenly spaced along the edges of the pool figure.

I vote for pushing this off as a cosmetic change and provide the "line bending" technique as a workaround.


Gary Brown added a comment - 29/Jun/11 4:27 AM - edited

I build savara from the codehoop update site, so assume that I am picking this change up.

Not sure an autolayout would work, as in general one end of the message flow will be a task, and the other end a pool. The ideal approach would be to enable the user to manually place the anchor point on the pool boundary.

I don't mind making this a lower priority, with the line bending technique as an interim workaround, however the colloboration diagrams will become more important to jBPM when it starts handling send/receive messages, and at that point I think users will find it a pain to have to keep bending lines to get the correct visual representation.