-- Created on: 1992-04-06
-- 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.

package IGESData

    ---Purpose : basic description of an IGES Interface

uses  Standard, MMgt, TCollection, TColStd,
      LibCtl,   Interface, gp, Message
      -- gp for Trsf, used by basic notion Transformation Matrix - Location

is

    class Protocol;

    class IGESModel;

    deferred class IGESEntity;  -- includes directory part
    	-- following classes are used in directory part : effective types of
    	-- LineFont, Transf, etc... MUST inherit them, because of type checking

    	deferred class LineFontEntity;
	deferred class LevelListEntity;
	deferred class TransfEntity;        -- transformation matrix
    	deferred class ViewKindEntity;      -- single view or list of views
	deferred class LabelDisplayEntity;
	deferred class ColorEntity;
	deferred class NameEntity;          -- possible as property
	deferred class SingleParentEntity;  -- possible as associativity

    class UndefinedEntity;
    class FreeFormatEntity;

    class GlobalSection;
    class DefSwitch;

    class DirChecker;

    class IGESReaderData;
    class IGESReaderTool;
    class ParamReader;
    class ParamCursor;
    class DirPart;             -- litteral description
    class IGESType;

    deferred class FileRecognizer  instantiates
    	Recognizer from Interface (IGESType, IGESEntity);

    class IGESWriter;
    class IGESDumper;
    class BasicEditor;

    class ToolLocation;

    deferred class GeneralModule;
    	class DefaultGeneral;
    deferred class ReadWriteModule;
    deferred class SpecificModule;  -- actions specific of IGES (Dump)
    	class DefaultSpecific;
    class FileProtocol;

    class WriterLib   instantiates  Library from LibCtl
    	(IGESEntity, ReadWriteModule, Protocol from IGESData);
    class SpecificLib instantiates  Library from LibCtl
    	(IGESEntity, SpecificModule,  Protocol from IGESData);

  	-- --   Enumerations   -- -- 
    enumeration  Status is 
       	EntityOK, 
    	EntityError, 
    	ReferenceError,
	TypeError;

    enumeration DefType is DefVoid, DefValue,  DefReference,
    	    	    	   DefAny,  ErrorVal,  ErrorRef;
    ---Purpose :  Some fields of an IGES entity may be
-- - Undefined
-- - Defined as a positive integer
-- - Defined as a reference to a specialized entity.
--  A typical example of this kind of variation is color.
-- This enumeration allows you to identify which of the above is the case.
-- The semantics of the terms are as follows:
-- - DefVoid indicates that the item contained in the field is undefined
-- - DefValue indicates that the item is defined as an immediate
--   positive integer value (i.e. not a pointer)
-- - DefReference indicates that the item is defined as an entity
-- - DefAny indicates the item could not be determined
-- - ErrorVal indicates that the item is defined as an integer
--   but its value is incorrect (it could be out of range, for example)
-- - ErrorRef indicates that the item is defined as an entity but
---    is not of the required type.

    enumeration DefList is DefNone, DefOne, DefSeveral, ErrorOne, ErrorSeveral;
    ---Purpose : Some fields of an IGES entity may be
-- - Undefined
-- - Defined as a single item
-- - Defined as a list of items.
--   A typical example, which presents this kind of variation,
-- is a level number.
-- This enumeration allows you to identify which of the above is the case.
-- The semantics of the terms is as follows:
-- - DefNone indicates that the list is empty (there is not
--   even a single item).
-- - DefOne indicates that the list contains a single item.
-- - DefSeveral indicates that the list contains several items.
-- - ErrorOne indicates that the list contains one item, but
--   that this item is incorrect
-- - ErrorSeveral indicates that the list contains several
--   items, but that at least one of them is incorrect.

    enumeration ReadStage is ReadDir, ReadOwn, ReadAssocs, ReadProps, ReadEnd;
    ---Purpose : gives successive stages of reading an entity (see ParamReader)

    	-- --   Instantiations   -- --

    class Array1OfDirPart instantiates Array1 from TCollection (DirPart);

    class Array1OfIGESEntity instantiates Array1 from TCollection (IGESEntity);

    class HArray1OfIGESEntity  instantiates
    	HArray1 from TCollection (IGESEntity,Array1OfIGESEntity); 
	
    	--   General Routines   --
    	-- They encapsulate the general actions required to work with this
    	-- package. While their use is not mandatory, it makes work easier.

    Init;
    ---Purpose : Prepares General dynamic data used for IGESData specifically :
    --           Protocol and Modules, which treat UndefinedEntity

    Protocol  returns Protocol from IGESData;
    ---Purpose : Returns a Protocol from IGESData (avoids to create it)

end IGESData;