Contents

• Public Types
• Public Functions
• Detailed Description

Detailed Description

TheQTextBoundaryFinder class provides a way of finding Unicode text boundaries in a string.

QTextBoundaryFinder allows to find Unicode text boundaries in a string, similar to the Unicode text boundary specification (see http://www.unicode.org/reports/tr29/tr29-11.html).

QTextBoundaryFinder can operate on aQString in four possible modes depending on the value ofBoundaryType.

Units of Unicode characters that make up what the user thinks of as a character or basic unit of the language are here called Grapheme clusters. The two unicode characters 'A' + diaeresis do for example form one grapheme cluster as the user thinks of them as one character, yet it is in this case represented by two unicode code points.

Word boundaries are there to locate the start and end of what a language considers to be a word.

Line break boundaries give possible places where a line break might happen and sentence boundaries will show the beginning and end of whole sentences.

The first position in a string is always a valid boundary and refers to the position before the first character. The last position at the length of the string is also valid and refers to the position after the last character.

Member Type Documentation

enum QTextBoundaryFinder::BoundaryReason
flags QTextBoundaryFinder::BoundaryReasons

The BoundaryReasons type is a typedef forQFlags<BoundaryReason>. It stores an OR combination of BoundaryReason values.

enum QTextBoundaryFinder::BoundaryType

Member Function Documentation

QTextBoundaryFinder::QTextBoundaryFinder()

Constructs an invalidQTextBoundaryFinder object.

QTextBoundaryFinder::QTextBoundaryFinder(constQTextBoundaryFinder & other)

Copies theQTextBoundaryFinder object,other.

QTextBoundaryFinder::QTextBoundaryFinder(BoundaryType type, constQString & string)

Creates aQTextBoundaryFinder object oftype operating onstring.

QTextBoundaryFinder::QTextBoundaryFinder(BoundaryType type, constQChar * chars,int length,unsignedchar * buffer = 0,int bufferSize = 0)

Creates aQTextBoundaryFinder object oftype operating onchars withlength.

buffer is an optional working buffer of sizebufferSize you can pass to theQTextBoundaryFinder. If the buffer is large enough to hold the working data required, it will use this instead of allocating its own buffer.

Warning:QTextBoundaryFinder does not create a copy ofchars. It is the application programmer's responsibility to ensure the array is allocated for as long as theQTextBoundaryFinder object stays alive. The same applies tobuffer.

QTextBoundaryFinder::~QTextBoundaryFinder()

Destructs theQTextBoundaryFinder object.

BoundaryReasons QTextBoundaryFinder::boundaryReasons() const

Returns the reasons for the boundary finder to have chosen the current position as a boundary.

bool QTextBoundaryFinder::isAtBoundary() const

Returns true if the object'sposition() is currently at a valid text boundary.

bool QTextBoundaryFinder::isValid() const

Returns true if the text boundary finder is valid; otherwise returns false. A defaultQTextBoundaryFinder is invalid.

int QTextBoundaryFinder::position() const

Returns the current position of theQTextBoundaryFinder.

The range is from 0 (the beginning of the string) to the length of the string inclusive.

See alsosetPosition().

void QTextBoundaryFinder::setPosition(int position)

Sets the current position of theQTextBoundaryFinder toposition.

Ifposition is out of bounds, it will be bound to only valid positions. In this case, valid positions are from 0 to the length of the string inclusive.

See alsoposition().

QString QTextBoundaryFinder::string() const

Returns the string theQTextBoundaryFinder object operates on.

void QTextBoundaryFinder::toEnd()

Moves the finder to the end of the string. This is equivalent tosetPosition(string.length()).

See alsosetPosition() andposition().

int QTextBoundaryFinder::toNextBoundary()

Moves theQTextBoundaryFinder to the next boundary position and returns that position.

Returns -1 if there is no next boundary.

int QTextBoundaryFinder::toPreviousBoundary()

Moves theQTextBoundaryFinder to the previous boundary position and returns that position.

Returns -1 if there is no previous boundary.

void QTextBoundaryFinder::toStart()

Moves the finder to the start of the string. This is equivalent tosetPosition(0).

See alsosetPosition() andposition().

BoundaryType QTextBoundaryFinder::type() const

Returns the type of theQTextBoundaryFinder.

QTextBoundaryFinder & QTextBoundaryFinder::operator=(constQTextBoundaryFinder & other)

Assigns the object,other, to anotherQTextBoundaryFinder object.