Node Shape issue when updating diagram using UpdateModelAction

[sathya-1994]

I am using GLSP vscode extension(https://github.com/eclipse-glsp/glsp-vscode-integration) + GLSP server.

I am building graph using GModel (org.eclipse.glsp.graph.GGraph > org.eclipse.glsp.graph.impl.GNodeImpl > org.eclipse.glsp.graph.impl.GLabelImpl).

Screenshot:

When name of node is edited in the text file, we are triggering update model action(org.eclipse.glsp.server.features.core.model.UpdateModelAction.UpdateModelAction(GModelRoot, boolean)). We are generating new graph object(GGraph) and updating root element using UpdateModelAction.

Name will be updated in the diagram but node shape will not be retained .Ids of node and labels are same for both Graphs.
Screenshot: Node name changed from new to new1 in the text editor

If we perform layout operation on graph (alt + l) above layout issue will be fixed.

Steps to reproduce the issue:
We are triggering diagram update from xtext(sync between diagram and text editor). But we can reproduce this issue with below steps without xtext.

1. In org.eclipse.glsp.server.features.core.model.JsonFileGModelLoader class use below code to generate simple node(loadSourceModel() method) instead of generating graph object from gson parser.

    GGraph graph = new GGraphImpl();
    graph.setId(DefaultTypes.GRAPH + Integer.toString(0));
    graph.setType(DefaultTypes.GRAPH);
    GNodeImpl gNode = new GNodeImpl();
    gNode.setParent(graph);
    gNode.setId("node");
    gNode.setType("node");
    gNode.getCssClasses().add("node");
    gNode.setLayout(GConstants.Layout.VBOX);
    GDimensionImpl d = new GDimensionImpl();
    d.setWidth(50);
    d.setHeight(50);
    gNode.setSize(d);
   

2. org.eclipse.glsp.server.features.modelsourcewatcher.FileWatcher.notifyClient(ClientNotification) here call update action with below code.
   GGraph graph = new GGraphImpl();
   graph.setId(DefaultTypes.GRAPH + Integer.toString(0));
   graph.setType(DefaultTypes.GRAPH);
   GNodeImpl gNode = new GNodeImpl();
   gNode.setParent(graph);
   gNode.setId("node");
   gNode.setType("node");
   gNode.getCssClasses().add("node");
   gNode.setLayout(GConstants.Layout.VBOX);
   GDimensionImpl d = new GDimensionImpl();
   d.setWidth(50);
   d.setHeight(50);
   gNode.setSize(d);
   GLabelImpl gLabel = new GLabelImpl();
   gLabel.setId("label");
   gLabel.setText("new1");
   gLabel.setType(DefaultTypes.LABEL);
   gLabel.setParent(gNode);
   actionDispatcher.dispatch(clientNotification.clientId, new UpdateModelAction(graph));

3. Open the file on which you created graph in a text editor of vscode and press cltl + s (save operation).

4. Whenever save operation is performed on the file on which we generated graph, we are triggering update model action on the diagram.

[tortmayr]

Hi @sathya-1994
Short answer: To fix this issue you need to dispatch a RequestBoundsAction instead of an UpdateModelAction.
Explanation: The bounds (i.e size & width) of some components (e.g. labels) can not be computed on server-side because their actual size depends on how they are displayed & styled on client side. Therefore and update cycle in GLSP consists of the following flow:

1. Server sends a RequestBoundsAction to the client
2. Client computes the bounds (using sprotty's hidden rendering phase) and sends a ComputedBoundsAction to the server
3. The client applies the received bound, optionally post-processes the model and then sends the UpdateModelAction to the client.

Steps 2 & 3 are automated, so all you have to do is send a RequestBoundsAction if you want to trigger a model update.

FYI: We provide the ModelSubmissionHandler convenience class that can be used to trigger server-side updates.

[sathya-1994]

Thank you @tortmayr ,

I used RequestBoundsAction instead of UpdateModelAction and it fixed current issue.
Also I am using ModelSubmissionHandler to trigger server side updates.