Exiv2::ImageFactory Class Reference

Returns an Image instance of the specified type. More...

#include <image.hpp>

Static Public Member Functions

static BasicIo::UniquePtr createIo (const std::string &path, bool useCurl=true)
 Create the appropriate class type implemented BasicIo based on the protocol of the input. More...
 
static Image::UniquePtr open (const std::string &path, bool useCurl=true)
 Create an Image subclass of the appropriate type by reading the specified file. Image type is derived from the file contents. More...
 
static Image::UniquePtr open (const byte *data, size_t size)
 Create an Image subclass of the appropriate type by reading the provided memory. Image type is derived from the memory contents. More...
 
static Image::UniquePtr open (BasicIo::UniquePtr io)
 Create an Image subclass of the appropriate type by reading the provided BasicIo instance. Image type is derived from the data provided by io. The passed in io instance is (re)opened by this method. More...
 
static Image::UniquePtr create (ImageType type, const std::string &path)
 Create an Image subclass of the requested type by creating a new image file. If the file already exists, it will be overwritten. More...
 
static Image::UniquePtr create (ImageType type)
 Create an Image subclass of the requested type by creating a new image in memory. More...
 
static Image::UniquePtr create (ImageType type, BasicIo::UniquePtr io)
 Create an Image subclass of the requested type by writing a new image to a BasicIo instance. If the BasicIo instance already contains data, it will be overwritten. More...
 
static ImageType getType (const std::string &path)
 Returns the image type of the provided file. More...
 
static ImageType getType (const byte *data, size_t size)
 Returns the image type of the provided data buffer. More...
 
static ImageType getType (BasicIo &io)
 Returns the image type of data provided by a BasicIo instance. The passed in io instance is (re)opened by this method. More...
 
static AccessMode checkMode (ImageType type, MetadataId metadataId)
 Returns the access mode or supported metadata functions for an image type and a metadata type. More...
 
static bool checkType (ImageType type, BasicIo &io, bool advance)
 Determine if the content of io is an image of type. More...
 

Friends

bool Image::good () const
 

Detailed Description

Returns an Image instance of the specified type.

The factory is implemented as a static class.

Member Function Documentation

◆ checkMode()

static AccessMode Exiv2::ImageFactory::checkMode ( ImageType  type,
MetadataId  metadataId 
)
static

Returns the access mode or supported metadata functions for an image type and a metadata type.

Parameters
typeThe image type.
metadataIdThe metadata identifier.
Returns
Access mode for the requested image type and metadata identifier.
Exceptions
Error(kerUnsupportedImageType)if the image type is not supported.

◆ checkType()

static bool Exiv2::ImageFactory::checkType ( ImageType  type,
BasicIo io,
bool  advance 
)
static

Determine if the content of io is an image of type.

The advance flag determines if the read position in the stream is moved (see below). This applies only if the type matches and the function returns true. If the type does not match, the stream position is not changed. However, if reading from the stream fails, the stream position is undefined. Consult the stream state to obtain more information in this case.

Parameters
typeType of the image.
ioBasicIo instance to read from.
advanceFlag indicating whether the position of the io should be advanced by the number of characters read to analyse the data (true) or left at its original position (false). This applies only if the type matches.
Returns
true if the data matches the type of this class;
false if the data does not match

◆ create() [1/3]

static Image::UniquePtr Exiv2::ImageFactory::create ( ImageType  type)
static

Create an Image subclass of the requested type by creating a new image in memory.

Parameters
typeType of the image to be created.
Returns
An auto-pointer that owns an Image instance of the requested type.
Exceptions
ErrorIf the image type is not supported

◆ create() [2/3]

static Image::UniquePtr Exiv2::ImageFactory::create ( ImageType  type,
BasicIo::UniquePtr  io 
)
static

Create an Image subclass of the requested type by writing a new image to a BasicIo instance. If the BasicIo instance already contains data, it will be overwritten.

Parameters
typeType of the image to be created.
ioAn auto-pointer that owns a BasicIo instance that will be written to when creating a new image.
Note
This method 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.
Returns
An auto-pointer that owns an Image instance of the requested type. If the image type is not supported, the pointer is 0.

◆ create() [3/3]

static Image::UniquePtr Exiv2::ImageFactory::create ( ImageType  type,
const std::string &  path 
)
static

Create an Image subclass of the requested type by creating a new image file. If the file already exists, it will be overwritten.

Parameters
typeType of the image to be created.
pathImage file to create. File extension is ignored.
Returns
An auto-pointer that owns an Image instance of the requested type.
Exceptions
ErrorIf the image type is not supported.

◆ createIo()

static BasicIo::UniquePtr Exiv2::ImageFactory::createIo ( const std::string &  path,
bool  useCurl = true 
)
static

Create the appropriate class type implemented BasicIo based on the protocol of the input.

"-" path implies the data from stdin and it is handled by StdinIo. Http path can be handled by either HttpIo or CurlIo. Https, ftp paths are handled by CurlIo. Ssh, sftp paths are handled by SshIo. Others are handled by FileIo.

Parameters
pathImage file.
useCurlIndicate whether the libcurl is used or not. If it's true, http is handled by CurlIo. Otherwise it is handled by HttpIo.
Returns
An auto-pointer that owns an BasicIo instance.
Exceptions
ErrorIf the file is not found or it is unable to connect to the server to read the remote file.

◆ getType() [1/3]

static ImageType Exiv2::ImageFactory::getType ( BasicIo io)
static

Returns the image type of data provided by a BasicIo instance. The passed in io instance is (re)opened by this method.

Parameters
ioA BasicIo instance that provides image data. The contents of the image data are tested to determine the type.
Returns
Image type or Image::none if the type is not recognized.

◆ getType() [2/3]

static ImageType Exiv2::ImageFactory::getType ( const byte data,
size_t  size 
)
static

Returns the image type of the provided data buffer.

Parameters
dataPointer to a data buffer containing an image. The contents of the memory are tested to determine the image type.
sizeNumber of bytes pointed to by data.
Returns
Image type or Image::none if the type is not recognized.

◆ getType() [3/3]

static ImageType Exiv2::ImageFactory::getType ( const std::string &  path)
static

Returns the image type of the provided file.

Parameters
pathImage file. The contents of the file are tested to determine the image type. File extension is ignored.
Returns
Image type or Image::none if the type is not recognized.

◆ open() [1/3]

static Image::UniquePtr Exiv2::ImageFactory::open ( BasicIo::UniquePtr  io)
static

Create an Image subclass of the appropriate type by reading the provided BasicIo instance. Image type is derived from the data provided by io. The passed in io instance is (re)opened by this method.

Parameters
ioAn auto-pointer that owns a BasicIo instance that provides image data. The contents of the image data are tested to determine the type.
Note
This method 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.
Returns
An auto-pointer that owns an Image instance whose type matches that of the io data. If no image type could be determined, the pointer is 0.
Exceptions
ErrorIf opening the BasicIo fails

◆ open() [2/3]

static Image::UniquePtr Exiv2::ImageFactory::open ( const byte data,
size_t  size 
)
static

Create an Image subclass of the appropriate type by reading the provided memory. Image type is derived from the memory contents.

Parameters
dataPointer to a data buffer containing an image. The contents of the memory are tested to determine the image type.
sizeNumber of bytes pointed to by data.
Returns
An auto-pointer that owns an Image instance whose type matches that of the data buffer.
Exceptions
ErrorIf the memory contains data of an unknown image type.

◆ open() [3/3]

static Image::UniquePtr Exiv2::ImageFactory::open ( const std::string &  path,
bool  useCurl = true 
)
static

Create an Image subclass of the appropriate type by reading the specified file. Image type is derived from the file contents.

Parameters
pathImage file. The contents of the file are tested to determine the image type. File extension is ignored.
useCurlIndicate whether the libcurl is used or not. If it's true, http is handled by CurlIo. Otherwise it is handled by HttpIo.
Returns
An auto-pointer that owns an Image instance whose type matches that of the file.
Exceptions
ErrorIf opening the file fails or it contains data of an unknown image type.
Examples
addmoddel.cpp, exifcomment.cpp, exifdata.cpp, exifprint.cpp, exifvalue.cpp, geotag.cpp, iptceasy.cpp, iptcprint.cpp, metacopy.cpp, mrwthumb.cpp, and xmpprint.cpp.

The documentation for this class was generated from the following file: