Exiv2::ExifKey Class Reference

Concrete keys for Exif metadata and access to Exif tag reference data. More...

#include <tags.hpp>

Inheritance diagram for Exiv2::ExifKey:

Public Types
using	UniquePtr = std::unique_ptr< ExifKey >
	Shortcut for an ExifKey auto pointer.
Public Types inherited from Exiv2::Key
using	UniquePtr = std::unique_ptr< Key >
	Shortcut for a Key auto pointer.

Public Member Functions
Creators
	ExifKey (const std::string &key)
	Constructor to create an Exif key from a key string.
	ExifKey (uint16_t tag, const std::string &groupName)
	Constructor to create an Exif key from the tag number and group name.
	ExifKey (const TagInfo &ti)
	Constructor to create an Exif key from a TagInfo instance.
	ExifKey (const ExifKey &rhs)
	Copy constructor.
	~ExifKey () override
	Destructor.
Manipulators
ExifKey &	operator= (const ExifKey &rhs)
	Assignment operator.
void	setIdx (int idx) const
	Set the index.
Public Member Functions inherited from Exiv2::Key
virtual	~Key ()=default
	Destructor.
	Key (Key &&)=delete
Key &	operator= (Key &&)=delete
UniquePtr	clone () const
	Return an auto-pointer to a copy of itself (deep copy). The caller owns this copy and the auto-pointer ensures that it will be deleted.
std::ostream &	write (std::ostream &os) const
	Write the key to an output stream. You do not usually have to use this function; it is used for the implementation of the output operator for Key, operator<<(std::ostream &os, const Key &key).

Accessors
std::string	key () const override
	Return the key of the metadatum as a string. The key is of the form 'familyName.groupName.tagName'. Note however that the key is not necessarily unique, e.g., an ExifData may contain multiple metadata with the same key.
const char *	familyName () const override
	Return an identifier for the type of metadata (the first part of the key)
std::string	groupName () const override
	Return the name of the group (the second part of the key)
IfdId	ifdId () const
	Return the IFD id. (Do not use, this is meant for library internal use.)
std::string	tagName () const override
	Return the name of the tag (which is also the third part of the key)
uint16_t	tag () const override
	Return the tag number.
std::string	tagLabel () const override
	Return a label for the tag.
std::string	tagDesc () const override
	Return a description for the tag.
TypeId	defaultTypeId () const
	Return the default type id for this tag.
UniquePtr	clone () const
int	idx () const
	Return the index (unique id of this key within the original Exif data, 0 if not set)

Additional Inherited Members
Protected Member Functions inherited from Exiv2::Key
	Key (const Key &)=default
Key &	operator= (const Key &)=default
	Assignment operator. Protected so that it can only be used by subclasses but not directly.

Detailed Description

Concrete keys for Exif metadata and access to Exif tag reference data.

Examples

addmoddel.cpp, and mrwthumb.cpp.

Constructor & Destructor Documentation

ExifKey() [1/3]

Exiv2::ExifKey::ExifKey ( const std::string &  key )

explicit

Constructor to create an Exif key from a key string.

Parameters

key	The key string.

Exceptions

Error

if the first part of the key is not 'Exif' or the remaining parts of the key cannot be parsed and converted to a group name and tag name.

ExifKey() [2/3]

Exiv2::ExifKey::ExifKey	(	uint16_t	tag,
		const std::string &	groupName
	)

Constructor to create an Exif key from the tag number and group name.

Parameters

tag	The tag value
groupName	The name of the group, i.e., the second part of the Exif key.

Exceptions

Error

if the key cannot be constructed from the tag number and group name.

ExifKey() [3/3]

Exiv2::ExifKey::ExifKey ( const TagInfo &  ti )

explicit

Constructor to create an Exif key from a TagInfo instance.

Parameters

ti	The TagInfo instance

Exceptions

Error

if the key cannot be constructed from the tag number and group name.

Member Function Documentation

familyName()

const char * Exiv2::ExifKey::familyName ( ) const

overridevirtual

Return an identifier for the type of metadata (the first part of the key)

Implements Exiv2::Key.

groupName()

std::string Exiv2::ExifKey::groupName ( ) const

overridevirtual

Return the name of the group (the second part of the key)

Implements Exiv2::Key.

key()

std::string Exiv2::ExifKey::key ( ) const

overridevirtual

Return the key of the metadatum as a string. The key is of the form 'familyName.groupName.tagName'. Note however that the key is not necessarily unique, e.g., an ExifData may contain multiple metadata with the same key.

Implements Exiv2::Key.

tag()

uint16_t Exiv2::ExifKey::tag ( ) const

overridevirtual

Return the tag number.

Implements Exiv2::Key.

tagDesc()

std::string Exiv2::ExifKey::tagDesc ( ) const

overridevirtual

Return a description for the tag.

Implements Exiv2::Key.

tagLabel()

std::string Exiv2::ExifKey::tagLabel ( ) const

overridevirtual

Return a label for the tag.

Implements Exiv2::Key.

tagName()

std::string Exiv2::ExifKey::tagName ( ) const

overridevirtual

Return the name of the tag (which is also the third part of the key)

Implements Exiv2::Key.

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

• tags.hpp