kanzi::TextShaper Class Reference

TextShaper encapsulates different shaping libraries, used by TextLayouter to perform BiDi layouting, text shaping and glyph substitution. More...

#include <kanzi/core.ui/text/text_shaper.hpp>

Inheritance diagram for kanzi::TextShaper:

Public Member Functions
virtual void	adjustPositions (TextLayouter::IntermediateLayout *layout, const TextLayouter::LineInfo &line) const
	This phase iterates through all layouted glyphs on the line and adjusts the positions based on shaping results.
virtual void	appendTerminator (unsigned int newSize, const TextLayouter::IntermediateLayout *terminator, unsigned int terminatorPosition)
	Updates the internal shaper structures to accommodate a terminator string, which replaces a part of the original text.
virtual void	cleanup ()
	Cleans up data used for shaping a specific text run.
uint8_t	getBaseBiDiLevel () const
	Gets the base bidi-level of the text.
virtual void	insertText (unsigned int location, const TextLayouter::IntermediateLayout *text)
	Updates the internal shaper structures to accommodate another string, which Kanzi inserts in the original text.
virtual vector< TextLayouter::CharacterInfo >	markBidiAndShape (const vector< char32_t > &unicodeText)
	This function performs the following operations.
virtual void	prepareLines (TextLayouter::IntermediateLayout *layout)
	Prepares the internal data structures after line breaking.
virtual void	removeText (unsigned int location, unsigned int length)
	When Kanzi truncates a part of text, updates the internal shaper structures in accordance with the changes to the shaped text during the text layout.
virtual void	reorderLine (TextLayouter::IntermediateLayout *layout, const TextLayouter::LineInfo &line)
	Reorders the text line for the text written right-to-left.
void	setBaseBiDiLevel (uint8_t baseBiDiLevel)
	Sets the base bidi-level of the text.
	TextShaper (const FontRuntime &font)
	Constructor.
virtual	~TextShaper ()
	Destructor.

Protected Member Functions
FontFile &	getFontFile (const FontRuntime &font) const
	Gets the font file that the passed font is currently using.

Protected Attributes
uint8_t	m_baseBiDiLevel
	The base bidi-level.
const FontRuntime &	m_font
	Font object used for shaping.

Detailed Description

TextShaper encapsulates different shaping libraries, used by TextLayouter to perform BiDi layouting, text shaping and glyph substitution.

TextLayouter calls the shaping functions for every text being layouted in the following order:

1. markBidiAndShape() for initial creation of layouting information
2. appendTerminator() for adding terminator (if text is truncated)
3. prepareLines() to prepare shaper internal data structures when line breaks are available
4. reorderLine() for every line to apply right-to-left formatting
5. adjustPositions() for every line to move characters to correct visual positions
6. cleanup() to allow shaper to clean internal data structures

Constructor & Destructor Documentation

TextShaper()

kanzi::TextShaper::TextShaper ( const FontRuntime & font )

explicit

Constructor.

Parameters

font	Font object used for shaping.

~TextShaper()

virtual kanzi::TextShaper::~TextShaper ( )

virtual

Destructor.

Member Function Documentation

markBidiAndShape()

virtual vector< TextLayouter::CharacterInfo > kanzi::TextShaper::markBidiAndShape ( const vector< char32_t > & unicodeText )

virtual

This function performs the following operations.

• Creates tags to indicate which parts of the text are written left-to-right and which right-to-left.
• Performs mirroring of specific character for the text written right-to-left.
• Performs text shaping.

  Parameters

  unicodeText

  Text to shape and mirror.

  Returns

  Layouting information per character.

Reimplemented in kanzi::FreeTypeTextShaper, and kanzi::ItypeTextShaper.

appendTerminator()

virtual void kanzi::TextShaper::appendTerminator ( unsigned int newSize, const TextLayouter::IntermediateLayout * terminator, unsigned int terminatorPosition )

virtual

Updates the internal shaper structures to accommodate a terminator string, which replaces a part of the original text.

Parameters

newSize	Size of text including terminator.
terminator	Pointer to intermediate layout containing terminator.
terminatorPosition	The position in the text buffer at which the terminator would be appended. This is needed for RTL text. For LTR text, the terminator position is always at the right-end of the text.

Reimplemented in kanzi::ItypeTextShaper.

insertText()

virtual void kanzi::TextShaper::insertText ( unsigned int location, const TextLayouter::IntermediateLayout * text )

virtual

Updates the internal shaper structures to accommodate another string, which Kanzi inserts in the original text.

For example, a hyphen.

Parameters

location	Position where the string is inserted.
text	Pointer to intermediate layout containing the text.

Reimplemented in kanzi::ItypeTextShaper.

removeText()

virtual void kanzi::TextShaper::removeText ( unsigned int location, unsigned int length )

virtual

When Kanzi truncates a part of text, updates the internal shaper structures in accordance with the changes to the shaped text during the text layout.

Parameters

location	Position at which the text is removed.
length	Length of the removed text.

Since

Kanzi 3.9.6

Reimplemented in kanzi::ItypeTextShaper.

prepareLines()

virtual void kanzi::TextShaper::prepareLines ( TextLayouter::IntermediateLayout * layout )

virtual

Prepares the internal data structures after line breaking.

Parameters

layout

Pointer to intermediate layout containing the text.

Reimplemented in kanzi::FreeTypeTextShaper.

reorderLine()

virtual void kanzi::TextShaper::reorderLine ( TextLayouter::IntermediateLayout * layout, const TextLayouter::LineInfo & line )

virtual

Reorders the text line for the text written right-to-left.

Parameters

layout	Pointer to intermediate layout containing the text.
line	Information defining the currently processed line.

Reimplemented in kanzi::FreeTypeTextShaper, and kanzi::ItypeTextShaper.

adjustPositions()

virtual void kanzi::TextShaper::adjustPositions ( TextLayouter::IntermediateLayout * layout, const TextLayouter::LineInfo & line ) const

virtual

This phase iterates through all layouted glyphs on the line and adjusts the positions based on shaping results.

Parameters

layout	Pointer to intermediate layout containing the text.
line	Information defining the currently processed line.

Reimplemented in kanzi::ItypeTextShaper.

cleanup()

virtual void kanzi::TextShaper::cleanup ( )

virtual

Cleans up data used for shaping a specific text run.

You need to call this function at the end of every shaping run.

Reimplemented in kanzi::FreeTypeTextShaper, and kanzi::ItypeTextShaper.

setBaseBiDiLevel()

void kanzi::TextShaper::setBaseBiDiLevel

(

uint8_t

baseBiDiLevel

)

Sets the base bidi-level of the text.

The base bidi-level is derived from the first character of strong bidirectional character type, in the provided text. For LTR or direction-neutral text set an even bidi-level, whereas for RTL text set an odd bidi-level.

Since

Kanzi 3.9.0

getBaseBiDiLevel()

uint8_t kanzi::TextShaper::getBaseBiDiLevel

(

)

const

Gets the base bidi-level of the text.

An even bidi-level represents LTR text direction, whereas an odd bidi-level represents RTL text direction.

Since

Kanzi 3.9.0

getFontFile()

FontFile & kanzi::TextShaper::getFontFile ( const FontRuntime & font ) const

protected

Gets the font file that the passed font is currently using.

Parameters

font	Font for which you want to get the font file that the font is currently using.

Returns

Font file that the passed font is currently using.

Member Data Documentation

m_font

const FontRuntime& kanzi::TextShaper::m_font

protected

Font object used for shaping.

m_baseBiDiLevel

uint8_t kanzi::TextShaper::m_baseBiDiLevel

protected

The base bidi-level.

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

• kanzi/core.ui/text/text_shaper.hpp