The QGlyphRun class provides direct access to the internal glyphs in a font. More...

Public Typedefs
using	GlyphRunFlags = QFlags< GlyphRunFlag >

Public Types
enum	GlyphRunFlag

Public Methods
	QGlyphRun ()

	QGlyphRun (const QGlyphRun &other)

	~QGlyphRun ()

QRectF	boundingRect () const

void	clear ()

GlyphRunFlags	flags () const

QVector< quint32 >	glyphIndexes () const

bool	isEmpty () const

bool	isRightToLeft () const

bool	operator!= (const QGlyphRun &other) const

QGlyphRun &	operator= (const QGlyphRun &other)

QGlyphRun &	operator= (QGlyphRun &&other)

bool	operator== (const QGlyphRun &other) const

bool	overline () const

QVector< QPointF >	positions () const

QRawFont	rawFont () const

void	setBoundingRect (const QRectF &boundingRect)

void	setFlag (GlyphRunFlag flag, bool enabled=true)

void	setFlags (GlyphRunFlags flags)

void	setGlyphIndexes (const QVector< quint32 > &glyphIndexes)

void	setOverline (bool overline)

void	setPositions (const QVector< QPointF > &positions)

void	setRawData (const quint32 glyphIndexArray, const QPointF glyphPositionArray, int size)

void	setRawFont (const QRawFont &rawFont)

void	setRightToLeft (bool rightToLeft)

void	setStrikeOut (bool strikeOut)

void	setUnderline (bool underline)

bool	strikeOut () const

void	swap (QGlyphRun &other)

bool	underline () const

Friends
class	QTextLine

Detailed Description

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

When CopperSpice 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 the QFont 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 to have low-level control over which glyphs in a specific font are drawn. This can occur in applications which use an external font engine and text shaper together with CopperSpice. 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 the selected font actually contains the provided glyph indexes.

QTextLayout::glyphRuns() or QTextFragment::glyphRuns() can be used to convert unicode encoded text into a list of QGlyphRun objects, and QPainter::drawGlyphRun() can be used to draw the glyphs.

Note: QRawFont is considered local to the thread in which it is constructed. This in turn means that a new QRawFont will have to be created and set on the QGlyphRun if it is moved to a different thread. If the QGlyphRun contains a reference to a QRawFont from a different thread than the current, it will not be possible to draw the glyphs using a QPainter, as the QRawFont is considered invalid and inaccessible in this case.

See also: setGlyphIndexes(), setPositions()

Member Typedef Documentation

QGlyphRun::GlyphRunFlags

Typedef for QFlags<GlyphRunFlag>. Refer to QGlyphRun::GlyphRunFlag for documentation.

Member Enumeration Documentation

enum QGlyphRun::GlyphRunFlag

This enum describes flags that alter the way the run of glyphs might be presented or behave in a visual layout. The layout which generates the glyph runs can set these flags based on relevant internal data, to retain information needed to present the text as intended by the user of the layout.

Constant	Value	Description
`QGlyphRun::Overline`	`0x01`	glyphs should be visualized together with an overline
`QGlyphRun::Underline`	`0x02`	glyphs should be visualized together with an underline
`QGlyphRun::StrikeOut`	`0x04`	glyphs should be struck out visually
`QGlyphRun::RightToLeft`	`0x08`	glyphs are ordered right to left, this can affect the positioning of other screen elements that are relative to the glyph run, such as an inline text object
`QGlyphRun::SplitLigature`	`0x10`	Indicates that the glyph run splits a ligature glyph. This means that a ligature glyph is included in the run, but the characters represented by it corresponds only to part of that ligature. The glyph run's boundingRect() function can in this case be used to retrieve the area covered by glyphs that correspond to the characters represented by the glyph run. When visualizing the glyphs, care needs to be taken to clip to this bounding rect to ensure that only the corresponding part of the ligature is painted. In particular, this can be the case when retrieving a glyph run from a QTextLayout for a specific character range, e.g. when retrieving the selected area of a QTextLayout.

Constructor & Destructor Documentation

QGlyphRun::QGlyphRun ( )

Constructs an empty QGlyphRun object.

QGlyphRun::QGlyphRun ( const QGlyphRun & other )

Constructs a QGlyphRun object which is a copy of other.

QGlyphRun::~QGlyphRun ( )

Destroys the QGlyphRun.

Method Documentation

QRectF QGlyphRun::boundingRect ( ) const

Returns the smallest rectangle that contains all glyphs in this QGlyphRun. If a bounding rect has been set using setBoundingRect(), then this will be returned. Otherwise the bounding rect will be calculated based on the font metrics of the glyphs in the glyph run.

See also: setBoundingRect()

void QGlyphRun::clear ( )

Clears all data in the QGlyphRun object.

GlyphRunFlags QGlyphRun::flags ( ) const

Returns the flags set for this QGlyphRun.

See also: setFlags(), setFlag(), setFlag()

QVector< quint32 > QGlyphRun::glyphIndexes ( ) const

Returns the glyph indexes for this QGlyphRun object.

See also: setGlyphIndexes(), setPositions()

bool QGlyphRun::isEmpty ( ) const

Returns true if the QGlyphRun does not contain any glyphs.

bool QGlyphRun::isRightToLeft ( ) const

Returns true if this QGlyphRun contains glyphs that are painted from the right to the left.

See also: setRightToLeft(), flags()

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

inline

Compares other to this QGlyphRun 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= ( const QGlyphRun & other )

Copy assigns from other and returns a reference to this object.

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

inline

Move assigns from other and returns a reference to this object.

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

Compares other to this QGlyphRun object. Returns true if the list of glyph indexes, the list of positions and the font are all equal, otherwise returns false.

bool QGlyphRun::overline ( ) const

Returns true if this QGlyphRun should be painted with an overline decoration.

See also: setOverline()

QVector< QPointF > QGlyphRun::positions ( ) const

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

See also: setPositions()

QRawFont QGlyphRun::rawFont ( ) const

Returns the font selected for this QGlyphRun object.

See also: setRawFont()

void QGlyphRun::setBoundingRect ( const QRectF & boundingRect )

Sets the bounding rect of the glyphs in this QGlyphRun to be boundingRect. This rectangle will be returned by boundingRect() unless it is empty, in which case the bounding rectangle of the glyphs in the glyph run will be returned instead.

Note: Unless you are implementing text shaping, you should not have to use this function. It is used specifically when the QGlyphRun should represent an area which is smaller than the area of the glyphs it contains. This could happen e.g. if the glyph run is retrieved by calling QTextLayout::glyphRuns() and the specified range only includes part of a ligature (where two or more characters are combined to a single glyph.) When this is the case, the bounding rect should only include the appropriate part of the ligature glyph, based on a calculation of the average width of the characters in the ligature.

In order to support such a case (an example is selections which should be drawn with a different color than the main text color), it is necessary to clip the painting mechanism to the rectangle returned from boundingRect() to avoid drawing the entire ligature glyph.

See also: boundingRect()

void QGlyphRun::setFlag	(	QGlyphRun::GlyphRunFlag	flag,
		bool	enabled = `true`
	)

If enabled is true, then flag is enabled, otherwise, it is disabled.

See also: flags(), setFlags()

void QGlyphRun::setFlags ( QGlyphRun::GlyphRunFlags flags )

Sets the flags of this QGlyphRun to flags.

See also: setFlag(), flags()

void QGlyphRun::setGlyphIndexes ( const QVector< quint32 > & glyphIndexes )

Set the glyph indexes for this QGlyphRun object to glyphIndexes. The glyph indexes must be valid for the selected font.

See also: glyphIndexes()

void QGlyphRun::setOverline ( bool overline )

Indicates that this QGlyphRun should be painted with an overline decoration if overline is true. Otherwise the QGlyphRun should be painted with no overline decoration.

See also: overline()

void QGlyphRun::setPositions ( const QVector< QPointF > & positions )

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

See also: positions()

void QGlyphRun::setRawData	(	const quint32 *	glyphIndexArray,
		const QPointF *	glyphPositionArray,
		int	size
	)

Sets the glyph indexes and positions of this QGlyphRun to use the first size elements in the arrays glyphIndexArray and glyphPositionArray. The data is not copied. The caller must guarantee that the arrays are not deleted as long as this QGlyphRun and any copies of it exists.

See also: setGlyphIndexes(), setPositions()

void QGlyphRun::setRawFont ( const QRawFont & rawFont )

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

See also: rawFont(), setGlyphIndexes()

void QGlyphRun::setRightToLeft ( bool rightToLeft )

Indicates that this QGlyphRun contains glyphs that should be ordered from the right to left if rightToLeft is true. Otherwise the order of the glyphs is assumed to be left to right.

See also: isRightToLeft(), setFlag(), setFlags()

void QGlyphRun::setStrikeOut ( bool strikeOut )

Indicates that this QGlyphRun should be painted with an strike out decoration if strikeOut is true. Otherwise the QGlyphRun should be painted with no strike out decoration.

See also: strikeOut()

void QGlyphRun::setUnderline ( bool underline )

Indicates that this QGlyphRun should be painted with an underline decoration if underline is true. Otherwise the QGlyphRun should be painted with no underline decoration.

See also: underline()

bool QGlyphRun::strikeOut ( ) const

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

See also: setStrikeOut()

void QGlyphRun::swap ( QGlyphRun & other )

inline

Swaps this glyph run instance with other. This function is very fast and never fails.

bool QGlyphRun::underline ( ) const

Returns true if this QGlyphRun should be painted with an underline decoration.

See also: setUnderline()

Public Typedefs

Public Types

Public Methods

Friends

Detailed Description

Member Typedef Documentation

Member Enumeration Documentation

Constructor & Destructor Documentation

Method Documentation