custom ELK layouting in Node.

[we-wake-act21]

I am trying to implement custom ELK Layouting for Node GLSP-server. I have configured layoutKind = ServerLayoutKind.AUTOMATIC; in the DiagramConfiguration. The values for GNode {position, size} are updated by my custom layouter but the final values that are sent back to the GLSP-client are the default values.

initial values

values after layouting

values sent back to client

this is happening because the root objects that is being modified by the layouter and the one sent back to the client are different

[tortmayr]

Hi @we-wake-act21,

thanks for raising this issue. I had a look the current implementation and it looks there is a bigger underlying problem with the implementation of server-side layouting. In its current design sever-side layouting (with our without elk) seems only to work for diagram languages that directly use the GModel as source model. However, most real-world applications use some sort of custom source model. This is currently not well supported. There is no way to apply the layout changes computed by ELK to the underlying source model.

We have to look into this and provide a better solution. I have created #1173 to track this.