-- Created on: 2002-02-22
-- Created by: Andrey BETENEV
-- Copyright (c) 2002-2014 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 ProgressSentry from Message 

    ---Purpose: This class is a tool allowing to manage opening/closing 
    --          scopes in the ProgressIndicator in convenient and safe way.
    --
    --          Its main features are:
    --          - Set all parameters for the current scale on the given 
    --            ProgressIndicator and open a new scope at one line
    --          - Iterator-like interface to opening next scopes and
    --            check for user break
    --          - Automatic scope closing in destructor
    --          - Safe for NULL ProgressIndicator (just does nothing)

uses
    HAsciiString from TCollection,
    ProgressIndicator from Message

is

    Create (PI: ProgressIndicator from Message; name: CString; 
            min, max, step: Real; isInf: Boolean = Standard_False;
    	    newScopeSpan: Real = 0.0);
    Create (PI: ProgressIndicator from Message; name: HAsciiString from TCollection; 
            min, max, step: Real; isInf: Boolean = Standard_False;
    	    newScopeSpan: Real = 0.0);
        ---Purpose: Creates an instance of ProgressSentry attaching it to
	--          the specified ProgressIndicator, selects parameters of
	--          the current scale, and opens a new scope with specified
	--          span (equal to step by default)

    Relieve (me: in out);
    	---C++: inline
    	---C++: alias ~
    	---Purpose: Moves progress indicator to the end of the current scale
        --          and relieves sentry from its duty. Methods other than Show() 
	--          will do nothing after this one is called.
	
    Next (me; name: CString = 0);
    	---C++: inline
    Next (me; span: Real; name: CString = 0); 
    	---C++: inline
    Next (me; span: Real; name: HAsciiString from TCollection); 
    	---C++: inline
    	---Purpose: Closes current scope and opens next one 
	--          with either specified or default span

    More (me) returns Boolean;
    	---C++: inline
	---Purpose: Returns False if ProgressIndicator signals UserBreak

    Show (me);
    	---C++: inline
	---Purpose: Forces update of progress indicator display

fields

    myProgress: ProgressIndicator from Message; 
    myActive: Boolean; -- True if ProgressIndicator is non-Null and scope is opened

end ProgressSentry;