Contents

• Public Functions
• Detailed Description

Detailed Description

TheQGlyphRun class provides direct access to the internal glyphs in a font.

When Qt displays a string of text encoded in Unicode, it will first convert the Unicode points into a list of glyph indexes and a list of positions based on one or more fonts. The Unicode representation of the text and theQFont object will in this case serve as a convenient abstraction that hides the details of what actually takes place when displaying the text on-screen. For instance, by the time the text actually reaches the screen, it may be represented by a set of fonts in addition to the one specified by the user, e.g. in case the originally selected font did not support all the writing systems contained in the text.

Under certain circumstances, it can be useful as an application developer to have more low-level control over which glyphs in a specific font are drawn to the screen. This could for instance be the case in applications that use an external font engine and text shaper together with Qt.QGlyphRun provides an interface to the raw data needed to get text on the screen. It contains a list of glyph indexes, a position for each glyph and a font.

It is the user's responsibility to ensure that the selected font actually contains the provided glyph indexes.

QTextLayout::glyphRuns() orQTextFragment::glyphRuns() can be used to convert unicode encoded text into a list ofQGlyphRun objects, andQPainter::drawGlyphRun() can be used to draw the glyphs.

Note:Please note thatQRawFont is considered local to the thread in which it is constructed. This in turn means that a newQRawFont will have to be created and set on theQGlyphRun if it is moved to a different thread. If theQGlyphRun contains a reference to aQRawFont from a different thread than the current, it will not be possible to draw the glyphs using aQPainter, as theQRawFont is considered invalid and inaccessible in this case.

Member Function Documentation

QGlyphRun::QGlyphRun()

Constructs an emptyQGlyphRun object.

QGlyphRun::QGlyphRun(constQGlyphRun & other)

Constructs aQGlyphRun object which is a copy ofother.

QGlyphRun::~QGlyphRun()

Destroys theQGlyphRun.

void QGlyphRun::clear()

Clears all data in theQGlyphRun object.

QVector<quint32> QGlyphRun::glyphIndexes() const

Returns the glyph indexes for thisQGlyphRun object.

See alsosetGlyphIndexes() andsetPositions().

bool QGlyphRun::overline() const

Returns true if thisQGlyphRun should be painted with an overline decoration.

See alsosetOverline().

QVector<QPointF> QGlyphRun::positions() const

Returns the position of the edge of the baseline for each glyph in this set of glyph indexes.

See alsosetPositions().

QRawFont QGlyphRun::rawFont() const

Returns the font selected for thisQGlyphRun object.

See alsosetRawFont().

void QGlyphRun::setGlyphIndexes(constQVector<quint32> & glyphIndexes)

Set the glyph indexes for thisQGlyphRun object toglyphIndexes. The glyph indexes must be valid for the selected font.

See alsoglyphIndexes().

void QGlyphRun::setOverline(bool overline)

Indicates that thisQGlyphRun should be painted with an overline decoration ifoverline is true. Otherwise theQGlyphRun should be painted with no overline decoration.

See alsooverline().

void QGlyphRun::setPositions(constQVector<QPointF> & positions)

Sets the positions of the edge of the baseline for each glyph in this set of glyph indexes topositions.

See alsopositions().

void QGlyphRun::setRawData(constquint32 * glyphIndexArray, constQPointF * glyphPositionArray,int size)

Sets the glyph indexes and positions of thisQGlyphRun to use the firstsize elements in the arraysglyphIndexArray andglyphPositionArray. The data isnot copied. The caller must guarantee that the arrays are not deleted as long as thisQGlyphRun and any copies of it exists.

See alsosetGlyphIndexes() andsetPositions().

void QGlyphRun::setRawFont(constQRawFont & rawFont)

Sets the font specified byrawFont to be the font used to look up the glyph indexes.

See alsorawFont() andsetGlyphIndexes().

void QGlyphRun::setStrikeOut(bool strikeOut)

Indicates that thisQGlyphRun should be painted with an strike out decoration ifstrikeOut is true. Otherwise theQGlyphRun should be painted with no strike out decoration.

See alsostrikeOut().

void QGlyphRun::setUnderline(bool underline)

Indicates that thisQGlyphRun should be painted with an underline decoration ifunderline is true. Otherwise theQGlyphRun should be painted with no underline decoration.

See alsounderline().

bool QGlyphRun::strikeOut() const

Returns true if thisQGlyphRun should be painted with a strike out decoration.

See alsosetStrikeOut().

bool QGlyphRun::underline() const

Returns true if thisQGlyphRun should be painted with an underline decoration.

See alsosetUnderline().

bool QGlyphRun::operator!=(constQGlyphRun & other) const

Comparesother to thisQGlyphRun object. Returns true if any of the list of glyph indexes, the list of positions or the font are different, otherwise returns false.

QGlyphRun & QGlyphRun::operator=(constQGlyphRun & other)

Assignsother to thisQGlyphRun object.

bool QGlyphRun::operator==(constQGlyphRun & other) const

Comparesother to thisQGlyphRun object. Returns true if the list of glyph indexes, the list of positions and the font are all equal, otherwise returns false.