Waypoints for reactions like AX + BY -> AY + BX

[ariutta]

@AlexanderPico and I discussed an idea for Interactions as described in the "pathvisiojs and PathVisio-Java Coordination" Google Doc. To better handle reactions of the type AX + BY -> AY + BX, we could add special GPML Anchors or Waypoints. If this change is part of GPML2017a, it might mean a Point could have a GraphId.

[ariutta]

Does this belong in this repo, or the PathVisio-Java repo?

[egonw]

I like to get Ryan's comment too, as he is coordinating the Maastricht interaction work. See also #15

[ariutta]

See also our Discussions Points doc

[mkutmon]

Point can already have a graphId - it's optional at the moment but I guess from a GPML point of view this is already possible. Implementing this in the GUI is another story... Not sure how we would do that. And not sure if it should be in 2017a discussion. We just need to make sure that whatever we would want to have in the GPML to represent those type of interactions actually is possible. So if having a graphId on a point that can be referenced in another Point is enough.

[AlexanderPico]

Anders and I has a productive discussion about this tricky issue (after a lot of coffee) and worked out some really nice features. Then we worked back to what's needed for GPML2017a to support these. We need:

• New element: AnchorGroup, with Anchor attributes (Position, Shape) and AnchorGroupId
• New attribute for Anchors: AnchorGroupRef

[mkutmon]

@AlexanderPico @ariutta we will plan another meeting about GPML2021. it would be great if we all could have another look at this issue before the meeting. we are stuck with what to do about this.