-- File:	SelectModelRoots.cdl
-- Created:	Tue Nov 17 18:52:56 1992
-- Author:	Christian CAILLET
--		<cky@topsn2>
---Copyright:	 Matra Datavision 1992


class SelectModelRoots  from IFSelect  inherits SelectBase

    ---Purpose : A SelectModelRoots gets all the Root Entities of an
    --           InterfaceModel. Remember that a "Root Entity" is defined as
    --           having no Sharing Entity (if there is a Loop between Entities,
    --           none of them can be a "Root").

uses AsciiString from TCollection, EntityIterator, Graph

is

    Create  returns mutable SelectModelRoots;
    ---Purpose : Creates a SelectModelRoot

    RootResult (me; G : Graph) returns EntityIterator;
    ---Purpose : Returns the list of selected entities : the Roots of the Model
    --           (note that this result assures naturally uniqueness)

    Label (me) returns AsciiString from TCollection;
    ---Purpose : Returns a text defining the criterium : "Model Roots"

end SelectModelRoots;