-- File:	SelectEntityNumber.cdl
-- Created:	Wed Nov 18 17:26:53 1992
-- Author:	Christian CAILLET
--		<cky@topsn2>
---Copyright:	 Matra Datavision 1992


class SelectEntityNumber  from IFSelect  inherits SelectBase

    ---Purpose : A SelectEntityNumber gets in an InterfaceModel (through a
    --           Graph), the Entity which has a specified Number (its rank of
    --           adding into the Model) : there can be zero (if none) or one.
    --           The Number is not directly defined as an Integer, but as a
    --           Parameter, which can be externally controled

uses AsciiString from TCollection, EntityIterator, Graph, IntParam

is

    Create  returns mutable SelectEntityNumber;
    ---Purpose : Creates a SelectEntityNumber, initially with no specified Number

    SetNumber (me : mutable; num : mutable IntParam);
    ---Purpose : Sets Entity Number to be taken (initially, none is set : 0)

    Number (me) returns mutable IntParam;
    ---Purpose : Returns specified Number (as a Parameter)

    RootResult (me; G : Graph) returns EntityIterator;
    ---Purpose : Returns the list of selected entities : the Entity having the
    --           specified Number (this result assures naturally uniqueness)

    Label (me) returns AsciiString from TCollection;
    ---Purpose : Returns a text defining the criterium : "Entity Number ..."

fields

    thenum : IntParam;

end SelectEntityNumber;