Hide parent nodes in Xtext Outline View

Question

I'm working on an Xtext parser, and have run into an issue: With the IDE plugin for Eclipse, specifically the Outline view, it tends to show <unnamed> nodes, which I don't want to display.

Currently, the nodes are as so:

• SourceFile (simply the name of the file that I'm currently using)
  • TopLevelStatement
    • Declare
      • StructDeclaration
        • StructCreator
          • name=Identifier - Same identifier as below.
      • ClassDeclaration
        • ClassCreator
          • name=Identifier - Same identifier as below.
    • Identifier
      • ID (the terminal that comes with Xtext)

With all the mess above, if I do something such as:

class TestClass {}
struct TestStruct {}

I would expect:

• SourceFile
  • TestClass
  • TestStruct

But what I really get, is this:

• SourceFile
  • <unnamed>
    • <unnamed>
      • <unnamed>
        • <unnamed>
          • TestClass
  • <unnamed>
    • <unnamed>
      • <unnamed>
        • <unnamed>
          • TestStruct

I really just want to hide every <unnamed> node in my Xtext project, as it would be beneficial to every case where I don't want something to appear, however if not possible, I simply want the specific nodes above to be hidden. I've tried the documentation, but can't seem to find any information as towards hiding a specific node, especially when it has multiple types of children.

Here is my grammar code:

SourceFile:
    (statements+=TopLevelStatement)*
;

TopLevelStatement:
    statement=(Declaration)
;

Declaration:
    declare=(StructDeclaration|ClassDeclaration)
;

StructDeclaration:
    declare=StructCreator '{' '}' ';'?
;

ClassDeclaration:
    declare=ClassCreator '{' '}' ';'?
;

StructCreator:
    'struct' id=Identifier
;

ClassCreator:
    'class' id=Identifier
;

Identifier:
    ID
;

You may look at the above code and ask why I don't merge the class and struct creators into one, but I can't. I'm going to have a few more rules for both the class and struct, which I haven't added, as they don't contribute to the problem.

Answer 1

In the first place i dont understand this wired object structure you create. is there any reason to do this the way you do it?

Step one: implement label provider

class MyDslLabelProvider extends DefaultEObjectLabelProvider {

    @Inject
    new(AdapterFactoryLabelProvider delegate) {
        super(delegate);
    }
    // xtext does reflective polymorphic dispatch on params
    def text(StructCreator ele) {
        ele.id
    }

    def text(ClassCreator ele) {
        ele.id
    }

}

Step two: Implement Outline Tree Provider

class MyDslOutlineTreeProvider extends DefaultOutlineTreeProvider {

    // xtext does reflective polymorphic dispatch on params
    def protected _createChildren(IOutlineNode parentNode, SourceFile modelElement) {
            for (s : modelElement.statements) {
                val firstDecl = s.statement?.declare
                if (firstDecl instanceof StructDeclaration) {
                    val secondDecl = firstDecl.declare
                    if (secondDecl !== null) {
                        createNode(parentNode, secondDecl)
                    }
                } else if (firstDecl instanceof ClassDeclaration) {
                    val secondDecl = firstDecl.declare
                    if (secondDecl !== null) {
                        createNode(parentNode, secondDecl)
                    }
                }

            }
    }

}

Alternative 0: Change Grammar and Naming Conventions

SourceFile:
    (statements+=TopLevelStatement)*
;

TopLevelStatement:
    Declaration
;

Declaration:
    StructDeclaration|ClassDeclaration
;

StructDeclaration:
    'struct' name=Identifier '{' '}' ';'?
;

ClassDeclaration:
    'class' name=Identifier '{' '}' ';'?
;

Identifier:
    ID
;