/*=========================================================================

Program:   Visualization Toolkit
Module:    vtkTextCodec.h

Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
All rights reserved.
See Copyright.txt or http://www.kitware.com/Copyright.htm for details.

This software is distributed WITHOUT ANY WARRANTY; without even
the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE.  See the above copyright notice for more information.

=========================================================================*/
/*-------------------------------------------------------------------------
  Copyright 2008 Sandia Corporation.
  Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
  the U.S. Government retains certain rights in this software.
-------------------------------------------------------------------------*/
// .NAME vtkTextCodec - Virtual class to act as an interface for all text codecs
//
// .SECTION Description
// A virtual class interface for codecs that readers/writers can rely on
//
// .SECTION Thanks
// Thanks to Tim Shed from Sandia National Laboratories for his work
// on the concepts and to Marcus Hanwell and Jeff Baumes of Kitware for
// keeping me out of the weeds
//
// .SECTION See Also
// vtkTextCodecFactory
//

#ifndef __vtkTextCodec_h
#define __vtkTextCodec_h

#include "vtkObject.h"
#include "vtkUnicodeString.h" // for the value type and for function return.

class VTK_IO_EXPORT vtkTextCodec : public vtkObject
{
public:
  vtkTypeMacro(vtkTextCodec, vtkObject);

  // Description:
  // The name this codec goes by - should match the string the factory will take
  // to create it
  virtual const char* Name();
  void PrintSelf(ostream& os, vtkIndent indent);

  virtual bool CanHandle(const char* NameString);

  // Description:
  // is the given sample valid for this codec?  The stream will not be advanced.
  virtual bool IsValid(istream& InputStream);

  // Description:
  // a base class that any output iterators need to derive from to use the first
  // signature of to_unicode.  Templates will not allow the vtable to
  // re-reference to the correct class so even though we only need the interface
  // we have to use derivation.
  class OutputIterator
  {
  public:
    virtual OutputIterator& operator++(int) = 0;
    virtual OutputIterator& operator*() = 0;
    virtual OutputIterator& operator=(const vtkUnicodeString::value_type value) = 0;

    OutputIterator() {}    virtual ~OutputIterator() {}

  private:
    OutputIterator(const OutputIterator&); // Not implemented
    const OutputIterator& operator=(const OutputIterator&); // Not Implemented
  };

  // Description:
  // Iterate through the sequence represented by the stream assigning the result
  // to the output iterator.  The stream will be advanced to its end so
  // subsequent use would need to reset it.
  virtual void ToUnicode(istream& InputStream,
                         vtkTextCodec::OutputIterator& output) = 0;

  // Description:
  // convinience method to take data from the stream and put it into a
  // vtkUnicodeString.
  vtkUnicodeString ToUnicode(istream & inputStream);

  // Description:
  // Return the next code point from the sequence represented by the stream
  // advancing the stream through however many places needed to assemble that
  // code point.
  virtual vtkUnicodeString::value_type NextUnicode(istream& inputStream) = 0;

//BTX
protected:
  vtkTextCodec();
  ~vtkTextCodec();

private:
  vtkTextCodec(const vtkTextCodec &); // Not implemented.
  void operator=(const vtkTextCodec &); // Not implemented.

//ETX
};

#endif