1929 treating groups as artifacts

[timonlazarviadee]

Proposed Changes

This pull request addresses the following issue: bpmn-io/bpmn-js#1929

It improves the handling of artifacts placed within swimminglanes in BPMN diagrams.

• When an artifact is positioned within a single swimminglane, it now correctly sticks to that lane.
• When an artifact overlaps multiple swimminglanes, it will not be assigned to any lane, ensuring consistent and predictable behavior.

Examples
Artifact sticking to the swimminglane:
https://github.com/user-attachments/assets/d3361f0d-3e17-4fab-976f-9e0612f59069

Artifact does not stick to any swimminglane:
https://github.com/user-attachments/assets/737d6b8f-ea43-40c5-ac6f-639e78119f29

Checklist

To ensure you provided everything we need to look at your PR:

• Brief textual description of the changes present
• Visual demo attached
• Steps to try out present, i.e. using the @bpmn-io/sr tool
• Related issue linked via Closes {LINK_TO_ISSUE} or Related to {LINK_TO_ISSUE}

[philippfromme]

The group also moves when it's not contained in the participant:

I would the fix to also work for artifacts like labels:

Besides, I was wondering if we want to implement it this way. Shouldn't the artifacts be moved to the appropriate parent when created/moved as mentioned here: #1929 (comment) This is not what the pull request implements. 🤔

[timonlazarviadee]

The group also moves when it's not contained in the participant:

I would the fix to also work for artifacts like labels:

Besides, I was wondering if we want to implement it this way. Shouldn't the artifacts be moved to the appropriate parent when created/moved as mentioned here: #1929 (comment) This is not what the pull request implements. 🤔

[timonlazarviadee]

Basically, I tried to attach the artifacts to the process, but they did not remain consistent. Furthermore, there was no direct way to evaluate them (in terms of size and coordinates). Therefore, I recommended attaching the artifacts in DiagramJs to the shape.move.start event. If there is another place where artifacts and their respective attributes can be evaluated, please let me know.

[timonlazarviadee]

I understood the comment https://github.com/bpmn-io/bpmn-js/issues/1929#issuecomment-1630818863 to mean that the group is included if it overlaps. It seems that what is meant here is that the group should be enclosed by the Group. Am I understanding this correctly?

[philippfromme]

I understood the comment https://github.com/bpmn-io/bpmn-js/issues/1929#issuecomment-1630818863 to mean that the group is included if it overlaps. It seems that what is meant here is that the group should be enclosed by the Group. Am I understanding this correctly?

This is something we can discuss. In my opinion, if it's not clearly inside a container it should not move. 🤔