jpgimage.hpp

// SPDX-License-Identifier: GPL-2.0-or-later
 
#ifndef JPGIMAGE_HPP_
#define JPGIMAGE_HPP_
 
#include "exiv2lib_export.h"
 
// included header files
#include "error.hpp"
#include "image.hpp"
 
// *****************************************************************************
// namespace extensions
namespace Exiv2 {
// *****************************************************************************
// class definitions
 
class EXIV2API JpegBase : public Image {
 public:
 
  void readMetadata() override;
  void writeMetadata() override;
  void printStructure(std::ostream& out, PrintStructureOption option, size_t depth) override;
 
 protected:
 
 
  JpegBase(ImageType type, BasicIo::UniquePtr io, bool create, const byte initData[], size_t dataSize);
 
 
 
  virtual bool isThisType(BasicIo& iIo, bool advance) const = 0;
 
 
 
  virtual int writeHeader(BasicIo& oIo) const = 0;
 
  int num_color_components_{-1};      
  std::string sof_encoding_process_;  
 
 private:
 
 
  int initImage(const byte initData[], size_t dataSize);
  void doWriteMetadata(BasicIo& outIo);
 
 
 
  [[nodiscard]] byte advanceToMarker(ErrorCode err) const;
 
  DataBuf readNextSegment(byte marker);
};
 
class EXIV2API JpegImage : public JpegBase {
  friend EXIV2API bool isJpegType(BasicIo& iIo, bool advance);
 
 public:
 
 
  JpegImage(BasicIo::UniquePtr io, bool create);
 
  [[nodiscard]] std::string mimeType() const override;
  [[nodiscard]] int numColorComponents() const {
    return num_color_components_;
  }
  [[nodiscard]] std::string encodingProcess() const {
    return sof_encoding_process_;
  }
 
 protected:
 
  bool isThisType(BasicIo& iIo, bool advance) const override;
 
 
  int writeHeader(BasicIo& outIo) const override;
 
 private:
  // Constant data
  static const byte blank_[];  
};
 
class EXIV2API ExvImage : public JpegBase {
  friend EXIV2API bool isExvType(BasicIo& iIo, bool advance);
 
 public:
 
 
  ExvImage(BasicIo::UniquePtr io, bool create);
 
  [[nodiscard]] std::string mimeType() const override;
 
 protected:
 
  bool isThisType(BasicIo& iIo, bool advance) const override;
 
  int writeHeader(BasicIo& outIo) const override;
 
 private:
  // Constant data
  static constexpr char exiv2Id_[] = "Exiv2";                                          // EXV identifier
  static constexpr byte blank_[] = {0xff, 0x01, 'E', 'x', 'i', 'v', '2', 0xff, 0xd9};  // Minimal exiv2 file
 
};  // class ExvImage
 
// *****************************************************************************
// template, inline and free functions
 
// These could be static private functions on Image subclasses but then
// ImageFactory needs to be made a friend.
EXIV2API Image::UniquePtr newJpegInstance(BasicIo::UniquePtr io, bool create);
EXIV2API bool isJpegType(BasicIo& iIo, bool advance);
EXIV2API Image::UniquePtr newExvInstance(BasicIo::UniquePtr io, bool create);
EXIV2API bool isExvType(BasicIo& iIo, bool advance);
 
}  // namespace Exiv2
 
#endif  // #ifndef JPGIMAGE_HPP_