pngchunk_int.hpp

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// ***************************************************************** -*- C++ -*-
/*
 * Copyright (C) 2004-2018 Exiv2 authors
 * This program is part of the Exiv2 distribution.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, 5th Floor, Boston, MA 02110-1301 USA.
 */
 /*
  File:    pngchunk.cpp
 */

#ifndef PNGCHUNK_INT_HPP_
#define PNGCHUNK_INT_HPP_

// *****************************************************************************
// included header files
#include "types.hpp"
#include "pngimage.hpp"

// + standard includes
#include <iosfwd>
#include <cassert>
#include <cstdarg>

// *****************************************************************************
// namespace extensions
namespace Exiv2 {

// *****************************************************************************
// class declarations
    class Image;

    namespace Internal {

// *****************************************************************************
// class definitions

    class PngChunk {
    public:
        enum TxtChunkType {
            tEXt_Chunk = 0,
            zTXt_Chunk = 1,
            iTXt_Chunk = 2
        };

    public:
        static void decodeIHDRChunk(const DataBuf& data,
                                    int*           outWidth,
                                    int*           outHeight);

        static void decodeTXTChunk(Image*         pImage,
                                   const DataBuf& data,
                                   TxtChunkType   type);

        static DataBuf decodeTXTChunk(const DataBuf& data,
                                     TxtChunkType   type);


        static DataBuf keyTXTChunk(const DataBuf& data, bool stripHeader=false);

        static std::string makeMetadataChunk(const std::string& metadata,
                                                   MetadataId   type);

    private:
        static DataBuf parseTXTChunk(const DataBuf& data,
                                     int            keysize,
                                     TxtChunkType   type);

        static void parseChunkContent(      Image*  pImage,
                                      const byte*   key,
                                            long    keySize,
                                      const DataBuf arr);

        static std::string makeAsciiTxtChunk(const std::string& keyword,
                                             const std::string& text,
                                             bool               compress);

        static std::string makeUtf8TxtChunk(const std::string& keyword,
                                            const std::string& text,
                                            bool               compress);

        static void zlibUncompress(const byte*  compressedText,
                                   unsigned int compressedTextSize,
                                   DataBuf&     arr);

        static std::string zlibCompress(const std::string& text);

        static DataBuf readRawProfile(const DataBuf& text,bool iTXt);

        static std::string writeRawProfile(const std::string& profileData,
                                           const char*        profileType);

        friend class Exiv2::PngImage;

    }; // class PngChunk

}}                                      // namespace Internal, Exiv2

#endif                                  // #ifndef PNGCHUNK_INT_HPP_