exiv2/include/exiv2/tiffimage.hpp

// SPDX-License-Identifier: GPL-2.0-or-later

#ifndef TIFFIMAGE_HPP_
#define TIFFIMAGE_HPP_

// *****************************************************************************
#include "exiv2lib_export.h"

// included header files
#include "image.hpp"

// *****************************************************************************
// namespace extensions
namespace Exiv2 {
// *****************************************************************************
// class definitions

/*!
  @brief Class to access TIFF images. Exif metadata is
      supported directly, IPTC is read from the Exif data, if present.
 */
class EXIV2API TiffImage : public Image {
 public:
  //! @name Creators
  //@{
  /*!
    @brief Constructor that can either open an existing TIFF image or create
        a new image from scratch. If a new image is to be created, any
        existing data is overwritten. Since the constructor can not return
        a result, callers should check the good() method after object
        construction to determine success or failure.
    @param io An auto-pointer that owns a BasicIo instance used for
        reading and writing image metadata. \b Important: The constructor
        takes ownership of the passed in BasicIo instance through the
        auto-pointer. Callers should not continue to use the BasicIo
        instance after it is passed to this method.  Use the Image::io()
        method to get a temporary reference.
    @param create Specifies if an existing image should be read (false)
        or if a new file should be created (true).
   */
  TiffImage(BasicIo::UniquePtr io, bool create);
  //@}

  //! @name Manipulators
  //@{
  void readMetadata() override;
  void writeMetadata() override;

  /*!
    @brief Print out the structure of image file.
    @throw Error if reading of the file fails or the image data is
          not valid (does not look like data of the specific image type).
    @warning This function is not thread safe and intended for exiv2 -p{S|R} as a file debugging aid
   */
  void printStructure(std::ostream& out, PrintStructureOption option, size_t depth) override;

  /*!
    @brief Not supported. TIFF format does not contain a comment.
        Calling this function will throw an Error(ErrorCode::kerInvalidSettingForImage).
   */
  void setComment(const std::string&) override;
  //@}

  //! @name Accessors
  //@{
  std::string mimeType() const override;
  uint32_t pixelWidth() const override;
  uint32_t pixelHeight() const override;
  //@}

 private:
  //! @name Accessors
  //@{
  //! Return the group name of the group with the primary image.
  std::string primaryGroup() const;
  //@}

  // DATA
  mutable std::string primaryGroup_;        //!< The primary group
  mutable std::string mimeType_;            //!< The MIME type
  mutable uint32_t pixelWidthPrimary_{0};   //!< Width of the primary image in pixels
  mutable uint32_t pixelHeightPrimary_{0};  //!< Height of the primary image in pixels

};  // class TiffImage

/*!
  @brief Stateless parser class for data in TIFF format. Images use this
         class to decode and encode TIFF data. It is a wrapper of the
         internal class Internal::TiffParserWorker.
 */
class EXIV2API TiffParser {
 public:
  /*!
    @brief Decode metadata from a buffer \em pData of length \em size
           with data in TIFF format to the provided metadata containers.

    @param exifData Exif metadata container.
    @param iptcData IPTC metadata container.
    @param xmpData  XMP metadata container.
    @param pData    Pointer to the data buffer. Must point to data in TIFF
                    format; no checks are performed.
    @param size     Length of the data buffer.

    @return Byte order in which the data is encoded.
  */
  static ByteOrder decode(ExifData& exifData, IptcData& iptcData, XmpData& xmpData, const byte* pData, size_t size);
  /*!
    @brief Encode metadata from the provided metadata to TIFF format.

    The original binary image in the memory block \em pData, \em size is
    parsed and updated in-place if possible ("non-intrusive" writing).
    If that is not possible (e.g., if new tags were added), the entire
    TIFF structure is re-written to the \em io instance ("intrusive" writing).<br>
    The return value indicates which write method was used. If it is
    \c wmNonIntrusive, the original memory \em pData, \em size contains
    the result and nothing is written to \em io. If the return value is
    \c wmIntrusive, a new TIFF structure was created and written to
    \em io. The memory block \em pData, \em size may be partly updated
    in this case and should not be used anymore.

    @note If there is no metadata to encode, i.e., all metadata
          containers are empty, then the return value is \c wmIntrusive
          and nothing is written to \em io, i.e., no TIFF header is written.

    @param io        IO instance to write the binary image to in case of
                     "intrusive" writing. Nothing is written to \em io in
                     the case of "non-intrusive" writing.
    @param pData     Pointer to the binary image data buffer. Must
                     point to data in TIFF format; no checks are
                     performed. Will be modified if "non-intrusive"
                     writing is possible.
    @param size      Length of the data buffer.
    @param byteOrder Byte order to use.
    @param exifData  Exif metadata container.
    @param iptcData  IPTC metadata container.
    @param xmpData   XMP metadata container.

    @return Write method used.
  */
  static WriteMethod encode(BasicIo& io, const byte* pData, size_t size, ByteOrder byteOrder, ExifData& exifData,
                            IptcData& iptcData, XmpData& xmpData);

};  // class TiffParser

// *****************************************************************************
// template, inline and free functions

// These could be static private functions on Image subclasses but then
// ImageFactory needs to be made a friend.
/*!
  @brief Create a new TiffImage instance and return an auto-pointer to it.
         Caller owns the returned object and the auto-pointer ensures that
         it will be deleted.
 */
EXIV2API Image::UniquePtr newTiffInstance(BasicIo::UniquePtr io, bool create);

//! Check if the file iIo is a TIFF image.
EXIV2API bool isTiffType(BasicIo& iIo, bool advance);

}  // namespace Exiv2

#endif  // #ifndef TIFFIMAGE_HPP_