ICU 58.2  58.2
Data Structures | Public Member Functions | Static Public Member Functions
icu::ParagraphLayout Class Reference

ParagraphLayout. More...

#include <ParagraphLayout.h>

Inheritance diagram for icu::ParagraphLayout:
icu::UObject icu::UMemory

Data Structures

class  Line
 This class represents a single line of text in a ParagraphLayout. More...
 
class  VisualRun
 This object represents a single visual run in a line of text in a paragraph. More...
 

Public Member Functions

 ParagraphLayout (const LEUnicode chars[], le_int32 count, const FontRuns *fontRuns, const ValueRuns *levelRuns, const ValueRuns *scriptRuns, const LocaleRuns *localeRuns, UBiDiLevel paragraphLevel, le_bool vertical, LEErrorCode &status)
 Construct a ParagraphLayout object for a styled paragraph. More...
 
 ~ParagraphLayout ()
 The destructor. More...
 
UBiDiLevel getParagraphLevel ()
 Return the resolved paragraph level. More...
 
UBiDiDirection getTextDirection ()
 Return the directionality of the text in the paragraph. More...
 
virtual le_int32 getAscent () const
 Return the max ascent value for all the fonts in the paragraph. More...
 
virtual le_int32 getDescent () const
 Return the max descent value for all the fonts in the paragraph. More...
 
virtual le_int32 getLeading () const
 Return the max leading value for all the fonts in the paragraph. More...
 
void reflow ()
 Reset line breaking to start from the beginning of the paragraph. More...
 
le_bool isDone () const
 Convenience method for determining if paragraph layout processing is complete ( i.e. More...
 
LinenextLine (float width)
 Return a ParagraphLayout::Line object which represents next line in the paragraph. More...
 
virtual UClassID getDynamicClassID () const
 ICU "poor man's RTTI", returns a UClassID for the actual class. More...
 
- Public Member Functions inherited from icu::UObject
virtual ~UObject ()
 Destructor. More...
 

Static Public Member Functions

static le_bool isComplex (const LEUnicode chars[], le_int32 count)
 Examine the given text and determine if it contains characters in any script which requires complex processing to be rendered correctly. More...
 
static UClassID getStaticClassID ()
 ICU "poor man's RTTI", returns a UClassID for this class. More...
 

Detailed Description

ParagraphLayout.

The ParagraphLayout object will analyze the text into runs of text in the same font, script and direction, and will create a LayoutEngine object for each run. The LayoutEngine will transform the characters into glyph codes in visual order.

Clients can use this to break a paragraph into lines, and to display the glyphs in each line.

Note that icu::LayoutEngine is deprecated, but this class is not. You may use this class with the HarfBuzz icu-le-hb wrapper, see http://www.freedesktop.org/wiki/Software/HarfBuzz/

See http://userguide.icu-project.org/layoutengine for special build instructions.

See also
icu::LayoutEngine

Definition at line 53 of file ParagraphLayout.h.

Constructor & Destructor Documentation

icu::ParagraphLayout::ParagraphLayout ( const LEUnicode  chars[],
le_int32  count,
const FontRuns fontRuns,
const ValueRuns levelRuns,
const ValueRuns scriptRuns,
const LocaleRuns localeRuns,
UBiDiLevel  paragraphLevel,
le_bool  vertical,
LEErrorCode &  status 
)

Construct a ParagraphLayout object for a styled paragraph.

The paragraph is specified as runs of text all in the same font. An LEFontInstance object and a limit offset are specified for each font run. The limit offset is the offset of the character immediately after the font run.

Clients can optionally specify directional runs and / or script runs. If these aren't specified they will be computed.

If any errors are encountered during construction, status will be set, and the object will be set to be empty.

Parameters
charsis an array of the characters in the paragraph
countis the number of characters in the paragraph.
fontRunsa pointer to a FontRuns object representing the font runs.
levelRunsis a pointer to a ValueRuns object representing the directional levels. If this pointer in NULL the levels will be determined by running the Unicde Bidi algorithm.
scriptRunsis a pointer to a ValueRuns object representing script runs. If this pointer in NULL the script runs will be determined using the Unicode code points.
localeRunsis a pointer to a LocaleRuns object representing locale runs. The Locale objects are used to determind the language of the text. If this pointer is NULL the default locale will be used for all of the text.
paragraphLevelis the directionality of the paragraph, as in the UBiDi object.
verticalis TRUE if the paragraph should be set vertically.
statuswill be set to any error code encountered during construction.
See also
ubidi.h
LEFontInstance.h
LayoutEngine.h
RunArrays.h
Stable:
ICU 2.8
icu::ParagraphLayout::~ParagraphLayout ( )

The destructor.

Virtual so that it works correctly with sublcasses.

Stable:
ICU 3.2

Member Function Documentation

virtual le_int32 icu::ParagraphLayout::getAscent ( ) const
virtual

Return the max ascent value for all the fonts in the paragraph.

Returns
the ascent value.
Stable:
ICU 3.2
virtual le_int32 icu::ParagraphLayout::getDescent ( ) const
virtual

Return the max descent value for all the fonts in the paragraph.

Returns
the decent value.
Stable:
ICU 3.2
virtual UClassID icu::ParagraphLayout::getDynamicClassID ( void  ) const
inlinevirtual

ICU "poor man's RTTI", returns a UClassID for the actual class.

Stable:
ICU 3.2

Reimplemented from icu::UObject.

Definition at line 555 of file ParagraphLayout.h.

virtual le_int32 icu::ParagraphLayout::getLeading ( ) const
virtual

Return the max leading value for all the fonts in the paragraph.

Returns
the leading value.
Stable:
ICU 3.2
UBiDiLevel icu::ParagraphLayout::getParagraphLevel ( )
inline

Return the resolved paragraph level.

This is useful for those cases where the bidi analysis has determined the level based on the first strong character in the paragraph.

Returns
the resolved paragraph level.
Stable:
ICU 3.2

Definition at line 650 of file ParagraphLayout.h.

References ubidi_getParaLevel().

static UClassID icu::ParagraphLayout::getStaticClassID ( void  )
inlinestatic

ICU "poor man's RTTI", returns a UClassID for this class.

Stable:
ICU 3.2

Definition at line 548 of file ParagraphLayout.h.

UBiDiDirection icu::ParagraphLayout::getTextDirection ( )
inline

Return the directionality of the text in the paragraph.

Returns
UBIDI_LTR if the text is all left to right, UBIDI_RTL if the text is all right to left, or UBIDI_MIXED if the text has mixed direction.
Stable:
ICU 3.2

Definition at line 655 of file ParagraphLayout.h.

References ubidi_getDirection().

static le_bool icu::ParagraphLayout::isComplex ( const LEUnicode  chars[],
le_int32  count 
)
static

Examine the given text and determine if it contains characters in any script which requires complex processing to be rendered correctly.

Parameters
charsis an array of the characters in the paragraph
countis the number of characters in the paragraph.
Returns
TRUE if any of the text requires complex processing.
Stable:
ICU 3.2
le_bool icu::ParagraphLayout::isDone ( ) const
inline

Convenience method for determining if paragraph layout processing is complete ( i.e.

there are no more lines left to process. )

Returns
true if there are no more lines to be processed
Internal:
Do not use. This API is for internal use only.
Line* icu::ParagraphLayout::nextLine ( float  width)

Return a ParagraphLayout::Line object which represents next line in the paragraph.

The width of the line is specified each time so that it can be varied to support arbitrary paragraph shapes.

Parameters
widthis the width of the line. If width is less than or equal to zero, a ParagraphLayout::Line object representing the rest of the paragraph will be returned.
Returns
a ParagraphLayout::Line object which represents the line. The caller is responsible for deleting the object. Returns NULL if there are no more lines in the paragraph.
See also
ParagraphLayout::Line
Stable:
ICU 3.2
void icu::ParagraphLayout::reflow ( )
inline

Reset line breaking to start from the beginning of the paragraph.

Stable:
ICU 3.2

Definition at line 660 of file ParagraphLayout.h.

References NULL.


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