pngchunk_int.hpp

// SPDX-License-Identifier: GPL-2.0-or-later
 
#ifndef PNGCHUNK_INT_HPP_
#define PNGCHUNK_INT_HPP_
 
// *****************************************************************************
// included header files
#include "pngimage.hpp"
#include "types.hpp"
 
// *****************************************************************************
// namespace extensions
namespace Exiv2::Internal {
// *****************************************************************************
// class definitions

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

  static void decodeIHDRChunk(const DataBuf& data, uint32_t* outWidth, uint32_t* 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, size_t keysize, TxtChunkType type);

  static void parseChunkContent(Image* pImage, const byte* key, size_t 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 Exiv2::Internal
 
#endif  // #ifndef PNGCHUNK_INT_HPP_