-- Created on: 1992-05-18
-- Created by: Stephan GARNAUD (ARM)
-- 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 Error from OSD

   ---Purpose: Accurate management of OSD specific errors.

--  Each method can be error tested with object.Failed().
--  To manage an occuring error, just use object.Perror(); 
--
--  It is possible to reset the error counter to zero.
--  To do this use the 'Reset' method .


--  Only 4 methods are usable for programmer :
--      Failed   to see whether an error occured or not.
--      Value    to get system independent error code.
--               (See annexe for a complete list of error code).
--      Reset    to reset error code to zero (no error).
--      Perror   to raise OSDError and print a self explanatory error
--               message. This message says why an error occurs and
--               explains what to do to correct it.

uses
  WhoAmI, AsciiString from TCollection

raises
  OSDError 

is
 Create returns Error;
   ---Purpose: Initializes Error to be without any Error.
   --          This is only used by OSD, not by programmer.
   ---Level: Public

 Perror (me : in out)
   ---Purpose: Raises OSD_Error with accurate error message.
   raises OSDError is static;
   ---Level: Public

 SetValue (me : in out; Errcode : Integer; From : Integer; Message : AsciiString) is static;
   ---Purpose: Instantiates error
   --          This is only used by OSD methods to instantiates an error code.
   --          No description is done for the programmer.
   ---Level: Public

 Error (me) returns Integer is static;
   ---Purpose: Returns an accurate error code.
   --          To test these values, you must include "OSD_ErrorList.hxx"
   ---Level: Public


 Failed (me) returns Boolean is static;
   ---Purpose: Returns TRUE if an error occurs
   --          This is a way to test if a system call succeeded or not.
   ---Level: Public

 Reset (me : in out) is static;
   ---Purpose: Resets error counter to zero
   --          This allows the user to ignore an error (WARNING).
   ---Level: Public

fields
   myMessage : AsciiString;   -- Internal error message
   myErrno   : Integer;  -- UNIX/VMS error used by OSD only
   myCode    : WhoAmI;   -- Accuracy code in error for OSD only
   extCode   : Integer;  -- Error type decoded for user
end Error from OSD;