/*
 * CDE - Common Desktop Environment
 *
 * Copyright (c) 1993-2012, The Open Group. All rights reserved.
 *
 * These libraries and programs are free software; you can
 * redistribute them and/or modify them under the terms of the GNU
 * Lesser General Public License as published by the Free Software
 * Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 * These libraries and programs are distributed in the hope that
 * they will be useful, but WITHOUT ANY WARRANTY; without even the
 * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 * PURPOSE. See the GNU Lesser General Public License for more
 * details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with these librararies and programs; if not, write
 * to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
 * Floor, Boston, MA 02110-1301 USA
 */
/* $XConsortium: CodingSystem.h /main/1 1996/07/29 16:48:04 cde-hp $ */
// Copyright (c) 1994 James Clark
// See the file COPYING for copying permission.

#ifndef CodingSystem_INCLUDED
#define CodingSystem_INCLUDED 1

#ifdef __GNUG__
#pragma interface
#endif

#ifndef SP_API
#define SP_API
#endif

#include "types.h"
#include "Boolean.h"
#include "StringC.h"

#include <stddef.h>

#if defined(linux)
#include <streambuf>
using namespace std;
#else
class streambuf;
#endif

#ifdef SP_NAMESPACE
namespace SP_NAMESPACE {
#endif

class SP_API Decoder {
public:
  Decoder(unsigned minBytesPerChar = 1);
  virtual ~Decoder();
  virtual size_t decode(Char *, const char *, size_t, const char **) = 0;
  virtual Boolean convertOffset(unsigned long &offset) const;
  // Decoder assumes that for every decoded Char there must be at least
  // minBytesPerChar bytes
  unsigned minBytesPerChar() const;
protected:
  unsigned minBytesPerChar_;
};


class SP_API Encoder {
public:
  class SP_API Handler {
  public:
    virtual void handleUnencodable(Char, streambuf *) = 0;
  };
  Encoder();
  virtual ~Encoder();
  virtual void output(const Char *, size_t, streambuf *) = 0;
  // This outputs a byte order mark with Unicode.
  virtual void startFile(streambuf *);
  virtual void output(Char *, size_t, streambuf *);
  void setUnencodableHandler(Handler *);
protected:
  void handleUnencodable(Char, streambuf *);
private:
  Handler *unencodableHandler_;
};

class SP_API InputCodingSystem {
public:
  virtual ~InputCodingSystem();
  virtual Decoder *makeDecoder() const = 0;
  StringC convertIn(const char *) const;
  virtual Boolean isIdentity() const;
};

class SP_API OutputCodingSystem {
public:
  virtual ~OutputCodingSystem();
  virtual Encoder *makeEncoder() const = 0;
  virtual unsigned fixedBytesPerChar() const;
  String<char> convertOut(const StringC &) const;
};

class SP_API CodingSystem : public InputCodingSystem, public OutputCodingSystem {
};

inline
unsigned Decoder::minBytesPerChar() const
{
  return minBytesPerChar_;
}

inline
void Encoder::handleUnencodable(Char c, streambuf *sbufp)
{
  if (unencodableHandler_)
    unencodableHandler_->handleUnencodable(c, sbufp);
}

inline
void Encoder::setUnencodableHandler(Handler *handler)
{
  unencodableHandler_ = handler;
}

#ifdef SP_NAMESPACE
}
#endif

#endif /* not CodingSystem_INCLUDED */