text: /****************************************************************************
  **
  ** Copyright (C) 2015 The Qt Company Ltd.
  ** Contact: http://www.qt.io/licensing/
  **
  ** This file is part of the Qt Messaging Framework.
  **
  ** $QT_BEGIN_LICENSE:LGPL21$
  ** Commercial License Usage
  ** Licensees holding valid commercial Qt licenses may use this file in
  ** accordance with the commercial license agreement provided with the
  ** Software or, alternatively, in accordance with the terms contained in
  ** a written agreement between you and The Qt Company. For licensing terms
  ** and conditions see http://www.qt.io/terms-conditions. For further
  ** information use the contact form at http://www.qt.io/contact-us.
  **
  ** GNU Lesser General Public License Usage
  ** Alternatively, this file may be used under the terms of the GNU Lesser
  ** General Public License version 2.1 or version 3 as published by the Free
  ** Software Foundation and appearing in the file LICENSE.LGPLv21 and
  ** LICENSE.LGPLv3 included in the packaging of this file. Please review the
  ** following information to ensure the GNU Lesser General Public License
  ** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
  ** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
  **
  ** As a special exception, The Qt Company gives you certain additional
  ** rights. These rights are described in The Qt Company LGPL Exception
  ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
  **
  ** $QT_END_LICENSE$
  **
  ****************************************************************************/
  
  #ifndef QMAILCODEC_H
  #define QMAILCODEC_H
  
  #include "qmailglobal.h"
  #include <QByteArray>
  #include <QDataStream>
  #include <QString>
  #include <QTextStream>
  
  class QMF_EXPORT QMailCodec
  {
  public:
      enum { ChunkCharacters = 8192 };
  
      virtual ~QMailCodec();
  
      virtual QString name() const = 0;
  
      // Stream conversion interface including character translation
      virtual void encode(QDataStream& out, QTextStream& in, const QString& charset = QLatin1String("UTF-8"));
      virtual void decode(QTextStream& out, QDataStream& in, const QString& charset);
  
      // Stream conversion interface
      virtual void encode(QDataStream& out, QDataStream& in);
      virtual void decode(QDataStream& out, QDataStream& in);
  
      // Convenience functions to encapsulate stream processing
      QByteArray encode(const QString& in, const QString& charset = QLatin1String("UTF-8"));
      QString decode(const QByteArray& in, const QString& charset);
  
      QByteArray encode(const QByteArray& in);
      QByteArray decode(const QByteArray& in);
  
      // Static helper functions
      static QTextCodec * codecForName(const QByteArray& charset, bool translateAscii = true);
      static QByteArray bestCompatibleCharset(const QByteArray& charset, bool translateAscii);
      static void copy(QDataStream& out, QDataStream& in);
      static void copy(QTextStream& out, QTextStream& in);
      static QString autoDetectEncoding(const QByteArray& text);
      static QString encodeModifiedUtf7(const QString &text);
      static QString decodeModifiedUtf7(const QString &text);
  
  protected:
      // Helper functions to convert stream chunks
      virtual void encodeChunk(QDataStream& out, const unsigned char* in, int length, bool finalChunk) = 0;
      virtual void decodeChunk(QDataStream& out, const char* in, int length, bool finalChunk) = 0;
  };
  
  class QMF_EXPORT QMailBase64Codec : public QMailCodec
  {
  public:
      enum ContentType { Text, Binary };
  
      QMailBase64Codec(ContentType content, int maximumLineLength = -1);
  
      virtual QString name() const;
  
  protected:
      virtual void encodeChunk(QDataStream& out, const unsigned char* in, int length, bool finalChunk);
      virtual void decodeChunk(QDataStream& out, const char* in, int length, bool finalChunk);
  
  private:
      ContentType _content;
      int _maximumLineLength;
  
      unsigned char _encodeBuffer[3];
      unsigned char* _encodeBufferOut;
      int _encodeLineCharsRemaining;
  
      unsigned char _decodeBuffer[4];
      unsigned char* _decodeBufferOut;
      int _decodePaddingCount;
  
      unsigned char _lastChar;
  };
  
  class QMF_EXPORT QMailQuotedPrintableCodec : public QMailCodec
  {
  public:
      enum ContentType { Text, Binary };
      enum ConformanceType { Rfc2045, Rfc2047 };
  
      QMailQuotedPrintableCodec(ContentType content, ConformanceType conformance, int maximumLineLength = -1);
  
      virtual QString name() const;
  
  protected:
      virtual void encodeChunk(QDataStream& out, const unsigned char* in, int length, bool finalChunk);
      virtual void decodeChunk(QDataStream& out, const char* in, int length, bool finalChunk);
  
  private:
      ContentType _content;
      ConformanceType _conformance;
      int _maximumLineLength;
  
      int _encodeLineCharsRemaining;
      unsigned char _encodeLastChar;
  
      char _decodePrecedingInput;
      unsigned char _decodeLastChar;
  };
  
  class QMF_EXPORT QMailPassThroughCodec : public QMailCodec
  {
      virtual QString name() const;
  
  protected:
      virtual void encodeChunk(QDataStream& out, const unsigned char* in, int length, bool finalChunk);
      virtual void decodeChunk(QDataStream& out, const char* in, int length, bool finalChunk);
  };
  
  class QMF_EXPORT QMailLineEndingCodec : public QMailCodec
  {
      virtual QString name() const;
  
  public:
      QMailLineEndingCodec();
  
  protected:
      virtual void encodeChunk(QDataStream& out, const unsigned char* in, int length, bool finalChunk);
      virtual void decodeChunk(QDataStream& out, const char* in, int length, bool finalChunk);
  
  private:
      unsigned char _lastChar;
  };
  
  #endif
  