QStringDecoder Class Reference

The QStringDecoder class provides a state-based decoder for text. \reentrant. More...

#include <qstringconverter.h>

Inheritance diagram for QStringDecoder:

Collaboration diagram for QStringDecoder:

Classes
struct	EncodedData

Public Member Functions
QSTRINGCONVERTER_CONSTEXPR	QStringDecoder (Encoding encoding, Flags flags=Flag::Default)
QSTRINGCONVERTER_CONSTEXPR	QStringDecoder ()
	QStringDecoder (const char *name, Flags f=Flag::Default)
Q_WEAK_OVERLOAD EncodedData< const QByteArray & >	operator() (const QByteArray &ba)
EncodedData< QByteArrayView >	operator() (QByteArrayView ba)
Q_WEAK_OVERLOAD EncodedData< const QByteArray & >	decode (const QByteArray &ba)
EncodedData< QByteArrayView >	decode (QByteArrayView ba)
qsizetype	requiredSpace (qsizetype inputLength) const
QChar *	appendToBuffer (QChar *out, QByteArrayView ba)
Public Member Functions inherited from QStringConverter
bool	isValid () const
void	resetState ()
bool	hasError () const
const char *	name () const

Protected Member Functions
QSTRINGCONVERTER_CONSTEXPR	QStringDecoder (const Interface *i)
Protected Member Functions inherited from QStringConverter
QSTRINGCONVERTER_CONSTEXPR	QStringConverter ()
QSTRINGCONVERTER_CONSTEXPR	QStringConverter (Encoding encoding, Flags f)
QSTRINGCONVERTER_CONSTEXPR	QStringConverter (const Interface *i)
Q_CORE_EXPORT	QStringConverter (const char *name, Flags f)

Additional Inherited Members
Public Types inherited from QStringConverter
enum	Encoding {   Utf8 , Utf16 , Utf16LE , Utf16BE ,   Utf32 , Utf32LE , Utf32BE , Latin1 ,   System , LastEncoding = System }
Public Types inherited from QStringConverterBase
enum class	Flag {   Default = 0 , Stateless = 0x1 , ConvertInvalidToNull = 0x2 , WriteBom = 0x4 ,   ConvertInitialBom = 0x8 }
Static Public Member Functions inherited from QStringConverter
static Q_CORE_EXPORT std::optional< Encoding >	encodingForName (const char *name)
static Q_CORE_EXPORT const char *	nameForEncoding (Encoding e)
static Q_CORE_EXPORT std::optional< Encoding >	encodingForData (QByteArrayView data, char16_t expectedFirstCharacter=0)
static Q_CORE_EXPORT std::optional< Encoding >	encodingForHtml (QByteArrayView data)
Protected Attributes inherited from QStringConverter
const Interface *	iface
State	state

Detailed Description

The QStringDecoder class provides a state-based decoder for text. \reentrant.

\inmodule QtCore

A text decoder converts text an encoded text format that uses a specific encoding into Qt's internal representation.

Converting encoded data into a QString can be achieved using the following code:

The decoder remembers any state that is required between calls, so converting data received in chunks, for example, when receiving it over a network, is just as easy, by calling the decoder whenever new data is available:

The QStringDecoder object maintains state between chunks and therefore works correctly even if chunks are split in the middle of a multi-byte character sequence.

QStringDecoder objects can't be copied because of their internal state, but can be moved.

See also

QStringConverter, QStringEncoder

Definition at line 251 of file qstringconverter.h.

Constructor & Destructor Documentation

QStringDecoder() [1/4]

constexpr QStringDecoder::QStringDecoder ( const Interface *  i )

inlineprotected

Definition at line 254 of file qstringconverter.h.

QStringDecoder() [2/4]

constexpr QStringDecoder::QStringDecoder ( Encoding  encoding, Flags  flags = Flag::Default  )

inline

Creates an decoder object using encoding and flags.

Definition at line 258 of file qstringconverter.h.

QStringDecoder() [3/4]

constexpr QStringDecoder::QStringDecoder ( )

inline

Default constructs an decoder. The default decoder is not valid, and can't be used for converting text.

Definition at line 261 of file qstringconverter.h.

QStringDecoder() [4/4]

constexpr QStringDecoder::QStringDecoder ( const char *  name, Flags  flags = Flag::Default  )

inline

Creates an decoder object using name and flags. If name is not the name of a known encoding an invalid converter will get created.

See also

isValid()

Definition at line 264 of file qstringconverter.h.

Member Function Documentation

appendToBuffer()

QChar * QStringDecoder::appendToBuffer ( QChar *  out, QByteArrayView  in  )

inline

Decodes the sequence of bytes viewed by in and writes the decoded result into the buffer starting at out. Returns a pointer to the end of data written.

out needs to be large enough to be able to hold all the decoded data. Use \l{requiredSpace} to determine the maximum size requirements to decode an encoded data buffer of in.size() bytes.

See also

requiredSpace

Definition at line 295 of file qstringconverter.h.

decode() [1/2]

QString QStringDecoder::decode ( const QByteArray &  ba )

inline

Definition at line 287 of file qstringconverter.h.

decode() [2/2]

QString QStringDecoder::decode ( QByteArrayView  ba )

inline

Converts ba and returns the data as a QString.

Definition at line 289 of file qstringconverter.h.

operator()() [1/2]

QString QStringDecoder::operator() ( const QByteArray &  ba )

inline

Definition at line 282 of file qstringconverter.h.

operator()() [2/2]

QString QStringDecoder::operator() ( QByteArrayView  ba )

inline

Definition at line 284 of file qstringconverter.h.

requiredSpace()

qsizetype QStringDecoder::requiredSpace ( qsizetype  inputLength ) const

inline

Returns the maximum amount of UTF-16 code units required to be able to process inputLength encoded data.

See also

appendToBuffer

Definition at line 293 of file qstringconverter.h.

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

• src/corelib/text/qstringconverter.h
• src/corelib/text/qstringconverter.cpp