-- Created on: 1992-12-02
-- Created by: Christian CAILLET
-- Copyright (c) 1992-1999 Matra Datavision
-- Copyright (c) 1999-2014 OPEN CASCADE SAS
--
-- This file is part of Open CASCADE Technology software library.
--
-- This library is free software; you can redistribute it and/or modify it under
-- the terms of the GNU Lesser General Public License version 2.1 as published
-- by the Free Software Foundation, with special exception defined in the file
-- OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
-- distribution for complete text of the license and disclaimer of any warranty.
--
-- Alternatively, this file may be used under the terms of Open CASCADE
-- commercial license or contractual agreement.

class SelectRootComps  from IFSelect  inherits SelectExtract

    ---Purpose : A SelectRootComps sorts the Entities which are part of Strong
    --           Componants, local roots of a set of Entities : they can be
    --           Single Componants (containing one Entity) or Cycles
    --           This class gives a more secure result than SelectRoots (which
    --           considers only Single Componants) but is longer to work : it
    --           can be used when there can be or there are cycles in a Model
    --           For each cycle, one Entity is given arbitrarily
    --           Reject works as for SelectRoots : Strong Componants defined in
    --           the input list which are not local roots are given

uses AsciiString from TCollection, InterfaceModel, EntityIterator, Graph

is

    Create returns SelectRootComps;
    ---Purpose : Creates a SelectRootComps

    RootResult (me; G : Graph) returns EntityIterator  is redefined;
    ---Purpose : Returns the list of local root strong componants, by one
    --           Entity par componant. It is redefined for a purpose of
    --           effeciency : calling a Sort routine for each Entity would
    --           cost more ressource than to work in once using a Map
    --           RootResult takes in account the Direct status

    HasUniqueResult (me) returns Boolean  is redefined protected;
    ---Purpose : Returns True, RootResult assuring uniqueness

    Sort (me; rank : Integer; ent : Transient; model : InterfaceModel)
    	returns Boolean;
    ---Purpose : Returns always True, because RootResult has done work

    ExtractLabel (me) returns AsciiString from TCollection;
    ---Purpose : Returns a text defining the criterium : "Local Root Componants"

end SelectRootComps;