facade::png::ZText Class Reference

A compressed text chunk. More...

#include <png.hpp>

Inheritance diagram for facade::png::ZText:

Public Member Functions
	ZText ()
	ZText (std::string keyword, std::string text)
	ZText (const Text &other)
bool	has_keyword () const
	Check if this ztXt chunk has a keyword set.
std::string	keyword () const
	The keyword value, if present.
void	set_keyword (std::string keyword, bool validate=true)
	Set the keyword of this zTXt chunk, with the option to validate the value given.
std::uint8_t	compression_method () const
	Return the compression method used for this zTXt chunk.
void	set_compression_method (std::uint8_t compression_method)
	Set the compression method for this zTXt chunk.
bool	has_text () const
	Check if the given zTXt chunk has a text value.
std::string	text () const
	Get the text data from this zTXt chunk.
void	set_text (std::string text)
	Set the text data for this `zTXt chunk.
Public Member Functions inherited from facade::png::ChunkVec
	ChunkVec (const ChunkTag tag)
	ChunkVec (const ChunkTag tag, const void *ptr, std::size_t size)
	ChunkVec (const ChunkTag tag, const std::vector< std::uint8_t > &data)
	ChunkVec (const ChunkVec &other)
bool	operator== (const ChunkVec &other) const
std::size_t	length () const
	Return the length of this chunk's data.
ChunkTag &	tag ()
	Return the chunk tag reference associated with this chunk.
const ChunkTag &	tag () const
	Return a const chunk tag reference associated with this chunk.
std::vector< std::uint8_t > &	data ()
	Return the chunk data reference associated with this chunk.
const std::vector< std::uint8_t > &	data () const
	Return const chunk data reference associated with this chunk.
void	set_data (std::vector< std::uint8_t > &data)
	Set the chunk data for this chunk.
std::uint32_t	crc () const
	Calculate the CRC value of this chunk.
std::pair< std::vector< std::uint8_t >, ChunkPtr >	to_chunk_ptr () const
	Convert this ChunkVec to a facade::png::ChunkPtr.
template<typename T >
T &	upcast ()
	Create a reference to a higher-level ChunkVec object, such as facade::png::Header.
template<typename T >
const T &	upcast () const
	Create a const reference to a higher-level ChunkVec object, such as facade::png::Header.
ChunkVec &	as_chunk_vec ()
	Interpret this ChunkVec derivative as a ChunkVec object.
const ChunkVec &	as_chunk_vec () const
	Interpret this ChunkVec derivative as a const ChunkVec object.

Protected Member Functions
std::optional< std::size_t >	null_terminator () const
	Get the null terminator, if present, separating the keyword from the text value.
std::size_t	text_offset () const
	Return the offset to the underlying text data.

Detailed Description

A compressed text chunk.

Constructor & Destructor Documentation

ZText() [1/3]

facade::png::ZText::ZText ( )

inline

ZText() [2/3]

facade::png::ZText::ZText ( std::string  keyword, std::string  text  )

inline

ZText() [3/3]

facade::png::ZText::ZText ( const Text &  other )

inline

Member Function Documentation

compression_method()

std::uint8_t ZText::compression_method

(

)

const

Return the compression method used for this zTXt chunk.

has_keyword()

bool ZText::has_keyword

(

)

const

Check if this ztXt chunk has a keyword set.

Returns

True if a keyword is present, false otherwise.

has_text()

bool ZText::has_text

(

)

const

Check if the given zTXt chunk has a text value.

Returns

True if text data is present, false otherwise.

keyword()

std::string ZText::keyword

(

)

const

The keyword value, if present.

Returns

A std::string representation of the keyword.

Exceptions

facade::exception::NoKeyword

null_terminator()

std::optional< std::size_t > ZText::null_terminator ( ) const

protected

Get the null terminator, if present, separating the keyword from the text value.

Returns

std::nullopt if no null terminator is present, the offset to the null terminator otherwise.

set_compression_method()

void ZText::set_compression_method

(

std::uint8_t

compression_method

)

Set the compression method for this zTXt chunk.

The only valid method is 0.

set_keyword()

void ZText::set_keyword	(	std::string	keyword,
		bool	validate = true
	)

Set the keyword of this zTXt chunk, with the option to validate the value given.

Parameters

keyword	The keyword string to set.
validate	Validate with an exception if the keyword is too long. Default is true.

Exceptions

facade::exception::KeywordTooLong

set_text()

void ZText::set_text

(

std::string

text

)

Set the text data for this `zTXt chunk.

text()

std::string ZText::text

(

)

const

Get the text data from this zTXt chunk.

text_offset()

std::size_t ZText::text_offset ( ) const

protected

Return the offset to the underlying text data.

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

• include/facade/png.hpp
• src/png.cpp