/* ******************************************************************************* * * Copyright (C) 1999, International Business Machines * Corporation and others. All Rights Reserved. * ******************************************************************************* * file name: ubidi.h * encoding: US-ASCII * tab size: 8 (not used) * indentation:4 * * created on: 1999jul27 * created by: Markus W. Scherer */ #ifndef UBIDI_H #define UBIDI_H #include "utypes.h" #include "uchar.h" /* * javadoc-style comments are intended to be transformed into HTML * using DOC++ - see * http://www.zib.de/Visual/software/doc++/index.html . * * The HTML documentation is created with * doc++ -H ubidi.h * * The following #define trick allows us to do it all in one file * and still be able to compile it. */ #define DOCXX_TAG #define BIDI_SAMPLE_CODE /** * @name BIDI algorithm for ICU * *
* *
pErrorCode
pointer must be valid
* and the value that it points to must not indicate a failure before
* the function call. Otherwise, the function returns immediately.
* After the function call, the value indicates success or failure.
*
* The limit
of a sequence of characters is the position just after their
* last character, i.e., one more than that position.
*
* Some of the API functions provide access to runs
.
* Such a run
is defined as a sequence of characters
* that are at the same embedding level
* after performing the BIDI algorithm.
* * @author Markus W. Scherer * @version 1.0 */ DOCXX_TAG /*@{*/ /** * UBiDiLevel is the type of the level values in this * BiDi implementation. * It holds an embedding level and indicates the visual direction * by its bit 0 (even/odd value).
*
* It can also hold non-level values for the
* paraLevel
and embeddingLevels
* arguments of ubidi_setPara()
; there:
*
embeddingLevels[]
* value indicates whether the using application is
* specifying the level of a character to override whatever the
* BiDi implementation would resolve it to.paraLevel
can be set to the
* pesudo-level values UBIDI_DEFAULT_LTR
* and UBIDI_DEFAULT_RTL
.The related constants are not real, valid level values.
* UBIDI_DEFAULT_XXX
can be used to specify
* a default for the paragraph level for
* when the ubidi_setPara()
function
* shall determine it but there is no
* strongly typed character in the input.
*
* Note that the value for UBIDI_DEFAULT_LTR
is even
* and the one for UBIDI_DEFAULT_RTL
is odd,
* just like with normal LTR and RTL level values -
* these special values are designed that way. Also, the implementation
* assumes that UBIDI_MAX_EXPLICIT_LEVEL is odd.
*
* @see UBIDI_DEFAULT_LTR
* @see UBIDI_DEFAULT_RTL
* @see UBIDI_LEVEL_OVERRIDE
* @see UBIDI_MAX_EXPLICIT_LEVEL
*/
typedef uint8_t UBiDiLevel;
/** Paragraph level setting.
* If there is no strong character, then set the paragraph level to 0 (left-to-right).
*/
#define UBIDI_DEFAULT_LTR 0xfe
/** Paragraph level setting.
* If there is no strong character, then set the paragraph level to 1 (right-to-left).
*/
#define UBIDI_DEFAULT_RTL 0xff
/**
* Maximum explicit embedding level.
* (The maximum resolved level can be up to UBIDI_MAX_EXPLICIT_LEVEL+1
).
*
*/
#define UBIDI_MAX_EXPLICIT_LEVEL 61
/** Bit flag for level input.
* Overrides directional properties.
*/
#define UBIDI_LEVEL_OVERRIDE 0x80
/**
* @memo UBiDiDirection
values indicate the text direction.
*/
enum UBiDiDirection {
/** @memo All left-to-right text. This is a 0 value. */
UBIDI_LTR,
/** @memo All right-to-left text. This is a 1 value. */
UBIDI_RTL,
/** @memo Mixed-directional text. */
UBIDI_MIXED
};
typedef enum UBiDiDirection UBiDiDirection;
/**
* Forward declaration of the UBiDi
structure for the declaration of
* the API functions. Its fields are implementation-specific.
* This structure holds information about a paragraph of text * with BiDi-algorithm-related details, or about one line of * such a paragraph.
* Reordering can be done on a line, or on a paragraph which is
* then interpreted as one single line.
*/
struct UBiDi;
typedef struct UBiDi UBiDi;
/**
* Allocate a UBiDi
structure.
* Such an object is initially empty. It is assigned
* the BiDi properties of a paragraph by ubidi_setPara()
* or the BiDi properties of a line of a paragraph by
* ubidi_getLine()
.
* This object can be reused for as long as it is not deallocated
* by calling ubidi_close()
.
* ubidi_set()
will allocate additional memory for
* internal structures as necessary.
*
* @return An empty UBiDi
object.
*/
U_CAPI UBiDi * U_EXPORT2
ubidi_open(void);
/**
* Allocate a UBiDi
structure with preallocated memory
* for internal structures.
* This function provides a UBiDi
object like ubidi_open()
* with no arguments, but it also preallocates memory for internal structures
* according to the sizings supplied by the caller.
* Subsequent functions will not allocate any more memory, and are thus * guaranteed not to fail because of lack of memory.
* The preallocation can be limited to some of the internal memory
* by setting some values to 0 here. That means that if, e.g.,
* maxRunCount
cannot be reasonably predetermined and should not
* be set to maxLength
(the only failproof value) to avoid
* wasting memory, then maxRunCount
could be set to 0 here
* and the internal structures that are associated with it will be allocated
* on demand, just like with ubidi_open()
.
*
* @param maxLength is the maximum paragraph or line length that internal memory
* will be preallocated for. An attempt to associate this object with a
* longer text will fail, unless this value is 0, which leaves the allocation
* up to the implementation.
*
* @param maxRunCount is the maximum anticipated number of same-level runs
* that internal memory will be preallocated for. An attempt to access
* visual runs on an object that was not preallocated for as many runs
* as the text was actually resolved to will fail,
* unless this value is 0, which leaves the allocation up to the implementation.
* The number of runs depends on the actual text and maybe anywhere between
* 1 and maxLength
. It is typically small.
*
* @param pErrorCode must be a valid pointer to an error code value,
* which must not indicate a failure before the function call.
*
* @return An empty UBiDi
object with preallocated memory.
*/
U_CAPI UBiDi * U_EXPORT2
ubidi_openSized(UTextOffset maxLength, UTextOffset maxRunCount, UErrorCode *pErrorCode);
/**
* ubidi_close()
must be called to free the memory
* associated with a UBiDi object.
*
* Important:
* If a UBiDi
object is the child
* of another one (its parent
), after calling
* ubidi_setLine()
, then the child object must
* be destroyed (closed) or reused (by calling
* ubidi_setPara()
or ubidi_setLine()
)
* before the parent object.
*
* @param pBiDi is a UBiDi
object.
*
* @see ubidi_setPara
* @see ubidi_setLine
*/
U_CAPI void U_EXPORT2
ubidi_close(UBiDi *pBiDi);
/**
* Perform the Unicode BiDi algorithm. It is defined in the
* Unicode Technical Report 9,
* version 5,
* also described in The Unicode Standard, Version 3.0 .
*
* This function takes a single plain text paragraph with or without
* externally specified embedding levels from styled
text
* and computes the left-right-directionality of each character.
*
* If the entire paragraph consists of text of only one direction, then
* the function may not perform all the steps described by the algorithm,
* i.e., some levels may not be the same as if all steps were performed.
* This is not relevant for unidirectional text.
* For example, in pure LTR text with numbers the numbers would get
* a resolved level of 2 higher than the surrounding text according to
* the algorithm. This implementation may set all resolved levels to
* the same value in such a case.
*
* The text must be externally split into separate paragraphs (rule P1).
* Paragraph separators (B) should appear at most at the very end.
*
* @param pBiDi A UBiDi
object allocated with ubidi_open()
* which will be set to contain the reordering information,
* especially the resolved levels for all the characters in text
.
*
* @param text is a pointer to the single-paragraph text that the
* BiDi algorithm will be performed on
* (step (P1) of the algorithm is performed externally).
* The text must be (at least) length
long.
*
* @param length is the length of the text; if length==-1
then
* the text must be zero-terminated.
*
* @param paraLevel specifies the default level for the paragraph;
* it is typically 0 (LTR) or 1 (RTL).
* If the function shall determine the paragraph level from the text,
* then paraLevel
can be set to
* either UBIDI_DEFAULT_LTR
* or UBIDI_DEFAULT_RTL
;
* if there is no strongly typed character, then
* the desired default is used (0 for LTR or 1 for RTL).
* Any other value between 0 and UBIDI_MAX_EXPLICIT_LEVEL
is also valid,
* with odd levels indicating RTL.
*
* @param embeddingLevels (in) may be used to preset the embedding and override levels,
* ignoring characters like LRE and PDF in the text.
* A level overrides the directional property of its corresponding
* (same index) character if the level has the
* UBIDI_LEVEL_OVERRIDE
bit set.
* Except for that bit, it must be
* paraLevel<=embeddingLevels[]<=UBIDI_MAX_EXPLICIT_LEVEL
.
* Caution: A copy of this pointer, not of the levels,
* will be stored in the UBiDi
object;
* the embeddingLevels
array must not be
* deallocated before the UBiDi
structure is destroyed or reused,
* and the embeddingLevels
* should not be modified to avoid unexpected results on subsequent BiDi operations.
* However, the ubidi_setPara()
and
* ubidi_setLine()
functions may modify some or all of the levels.
* After the UBiDi
object is reused or destroyed, the caller
* must take care of the deallocation of the embeddingLevels
array.
* The embeddingLevels
array must be
* at least length
long.
*
* @param pErrorCode must be a valid pointer to an error code value,
* which must not indicate a failure before the function call.
*/
U_CAPI void U_EXPORT2
ubidi_setPara(UBiDi *pBiDi, const UChar *text, UTextOffset length,
UBiDiLevel paraLevel, UBiDiLevel *embeddingLevels,
UErrorCode *pErrorCode);
/**
* ubidi_getLine()
sets a UBiDi
to
* contain the reordering information, especially the resolved levels,
* for all the characters in a line of text. This line of text is
* specified by referring to a UBiDi
object representing
* this information for a paragraph of text, and by specifying
* a range of indexes in this paragraph.
* In the new line object, the indexes will range from 0 to limit-start
.
*
* This is used after calling ubidi_setPara()
* for a paragraph, and after line-breaking on that paragraph.
* It is not necessary if the paragraph is treated as a single line.
*
* After line-breaking, rules (L1) and (L2) for the treatment of
* trailing WS and for reordering are performed on
* a UBiDi
object that represents a line.
*
* Important: pLineBiDi
shares data with
* pParaBiDi
.
* You must destroy or reuse pLineBiDi
before pParaBiDi
.
* In other words, you must destroy or reuse the UBiDi
object for a line
* before the object for its parent paragraph.
*
* @param pParaBiDi is the parent paragraph object.
*
* @param start is the line's first index into the paragraph text.
*
* @param limit is just behind the line's last index into the paragraph text
* (its last index +1).
* It must be 0<=start<=limit<=
paragraph length.
*
* @param pLineBiDi is the object that will now represent a line of the paragraph.
*
* @param pErrorCode must be a valid pointer to an error code value,
* which must not indicate a failure before the function call.
*
* @see ubidi_setPara
*/
U_CAPI void U_EXPORT2
ubidi_setLine(const UBiDi *pParaBiDi,
UTextOffset start, UTextOffset limit,
UBiDi *pLineBiDi,
UErrorCode *pErrorCode);
/**
* Get the directionality of the text.
*
* @param pBiDi is the paragraph or line UBiDi
object.
*
* @return A UBIDI_XXX
value that indicates if the entire text
* represented by this object is unidirectional,
* and which direction, or if it is mixed-directional.
*
* @see UBiDiDirection
*/
U_CAPI UBiDiDirection U_EXPORT2
ubidi_getDirection(const UBiDi *pBiDi);
/**
* Get the length of the text.
*
* @param pBiDi is the paragraph or line UBiDi
object.
*
* @return The length of the text that the UBiDi object was created for.
*/
U_CAPI UTextOffset U_EXPORT2
ubidi_getLength(const UBiDi *pBiDi);
/**
* Get the paragraph level of the text.
*
* @param pBiDi is the paragraph or line UBiDi
object.
*
* @return The paragraph level.
*
* @see UBiDiLevel
*/
U_CAPI UBiDiLevel U_EXPORT2
ubidi_getParaLevel(const UBiDi *pBiDi);
/**
* Get the level for one character.
*
* @param pBiDi is the paragraph or line UBiDi
object.
*
* @param charIndex the index of a character.
*
* @return The level for the character at charIndex.
*
* @see UBiDiLevel
*/
U_CAPI UBiDiLevel U_EXPORT2
ubidi_getLevelAt(const UBiDi *pBiDi, UTextOffset charIndex);
/**
* Get an array of levels for each character.
*
* Note that this function may allocate memory under some
* circumstances, unlike ubidi_getLevelAt()
.
*
* @param pBiDi is the paragraph or line UBiDi
object.
*
* @param pErrorCode must be a valid pointer to an error code value,
* which must not indicate a failure before the function call.
*
* @return The levels array for the text,
* or NULL
if an error occurs.
*
* @see UBiDiLevel
*/
U_CAPI const UBiDiLevel * U_EXPORT2
ubidi_getLevels(UBiDi *pBiDi, UErrorCode *pErrorCode);
/**
* Get a logical run.
* This function returns information about a run and is used
* to retrieve runs in logical order.
* This is especially useful for line-breaking on a paragraph.
*
* @param pBiDi is the paragraph or line UBiDi
object.
*
* @param logicalStart is the first character of the run.
*
* @param pLogicalLimit will receive the limit of the run.
* The l-value that you point to here may be the
* same expression (variable) as the one for
* logicalStart
.
* This pointer can be NULL
if this
* value is not necessary.
*
* @param pLevel will receive the level of the run.
* This pointer can be NULL
if this
* value is not necessary.
*/
U_CAPI void U_EXPORT2
ubidi_getLogicalRun(const UBiDi *pBiDi, UTextOffset logicalStart,
UTextOffset *pLogicalLimit, UBiDiLevel *pLevel);
/**
* Get the number of runs.
* This function may invoke the actual reordering on the
* UBiDi
object, after ubidi_setPara()
* may have resolved only the levels of the text. Therefore,
* ubidi_countRuns()
may have to allocate memory,
* and may fail doing so.
*
* @param pBiDi is the paragraph or line UBiDi
object.
*
* @param pErrorCode must be a valid pointer to an error code value,
* which must not indicate a failure before the function call.
*
* @return The number of runs.
*/
U_CAPI UTextOffset U_EXPORT2
ubidi_countRuns(UBiDi *pBiDi, UErrorCode *pErrorCode);
/**
* Get one run's logical start, length, and directionality,
* which can be 0 for LTR or 1 for RTL.
* In an RTL run, the character at the logical start is
* visually on the right of the displayed run.
* The length is the number of characters in the run.
* ubidi_countRuns()
should be called
* before the runs are retrieved.
*
* @param pBiDi is the paragraph or line UBiDi
object.
*
* @param runIndex is the number of the run in visual order, in the
* range [0..ubidi_countRuns(pBiDi)-1]
.
*
* @param pLogicalStart is the first logical character index in the text.
* The pointer may be NULL
if this index is not needed.
*
* @param pLength is the number of characters (at least one) in the run.
* The pointer may be NULL
if this is not needed.
*
* @return the directionality of the run,
* UBIDI_LTR==0
or UBIDI_RTL==1
,
* never UBIDI_MIXED
.
*
* @see ubidi_countRuns
*
* Example:
*
* UTextOffset i, count=ubidi_countRuns(pBiDi), * logicalStart, visualIndex=0, length; * for(i=0; i<count; ++i) { * if(UBIDI_LTR==ubidi_getVisualRun(pBiDi, i, &logicalStart, &length)) { * do { // LTR * show_char(text[logicalStart++], visualIndex++); * } while(--length>0); * } else { * logicalStart+=length; // logicalLimit * do { // RTL * show_char(text[--logicalStart], visualIndex++); * } while(--length>0); * } * } ** * Note that in right-to-left runs, code like this places * modifier letters before base characters and second surrogates * before first ones. */ U_CAPI UBiDiDirection U_EXPORT2 ubidi_getVisualRun(UBiDi *pBiDi, UTextOffset runIndex, UTextOffset *pLogicalStart, UTextOffset *pLength); /** * Get the visual position from a logical text position. * If such a mapping is used many times on the same *
UBiDi
object, then calling
* ubidi_getLogicalMap()
is more efficient.
*
* Note that in right-to-left runs, this mapping places
* modifier letters before base characters and second surrogates
* before first ones.
*
* @param pBiDi is the paragraph or line UBiDi
object.
*
* @param logicalIndex is the index of a character in the text.
*
* @param pErrorCode must be a valid pointer to an error code value,
* which must not indicate a failure before the function call.
*
* @return The visual position of this character.
*
* @see ubidi_getLogicalMap
* @see ubidi_getLogicalIndex
*/
U_CAPI UTextOffset U_EXPORT2
ubidi_getVisualIndex(UBiDi *pBiDi, UTextOffset logicalIndex, UErrorCode *pErrorCode);
/**
* Get the logical text position from a visual position.
* If such a mapping is used many times on the same
* UBiDi
object, then calling
* ubidi_getVisualMap()
is more efficient.
*
* This is the inverse function to ubidi_getVisualIndex()
.
*
* @param pBiDi is the paragraph or line UBiDi
object.
*
* @param visualIndex is the visual position of a character.
*
* @param pErrorCode must be a valid pointer to an error code value,
* which must not indicate a failure before the function call.
*
* @return The index of this character in the text.
*
* @see ubidi_getVisualMap
* @see ubidi_getVisualIndex
*/
U_CAPI UTextOffset U_EXPORT2
ubidi_getLogicalIndex(UBiDi *pBiDi, UTextOffset visualIndex, UErrorCode *pErrorCode);
/**
* Get a logical-to-visual index map (array) for the characters in the UBiDi
* (paragraph or line) object.
*
* @param pBiDi is the paragraph or line UBiDi
object.
*
* @param indexMap is a pointer to an array of ubidi_getLength()
* indexes which will reflect the reordering of the characters.
* The array does not need to be initialized.
* The index map will result in indexMap[logicalIndex]==visualIndex
.
*
* @param pErrorCode must be a valid pointer to an error code value,
* which must not indicate a failure before the function call.
*
* @see ubidi_getVisualMap
* @see ubidi_getVisualIndex
*/
U_CAPI void U_EXPORT2
ubidi_getLogicalMap(UBiDi *pBiDi, UTextOffset *indexMap, UErrorCode *pErrorCode);
/**
* Get a visual-to-logical index map (array) for the characters in the UBiDi
* (paragraph or line) object.
*
* @param pBiDi is the paragraph or line UBiDi
object.
*
* @param indexMap is a pointer to an array of ubidi_getLength()
* indexes which will reflect the reordering of the characters.
* The array does not need to be initialized.
* The index map will result in indexMap[visualIndex]==logicalIndex
.
*
* @param pErrorCode must be a valid pointer to an error code value,
* which must not indicate a failure before the function call.
*
* @see ubidi_getLogicalMap
* @see ubidi_getLogicalIndex
*/
U_CAPI void U_EXPORT2
ubidi_getVisualMap(UBiDi *pBiDi, UTextOffset *indexMap, UErrorCode *pErrorCode);
/**
* This is a convenience function that does not use a UBiDi object.
* It is intended to be used for when an application has determined the levels
* of objects (character sequences) and just needs to have them reordered (L2).
* This is equivalent to using ubidi_getLogicalMap
on a
* UBiDi
object.
*
* @param levels is an array with length
levels that have been determined by
* the application.
*
* @param length is the number of levels in the array, or, semantically,
* the number of objects to be reordered.
* It must be length>0
.
*
* @param indexMap is a pointer to an array of length
* indexes which will reflect the reordering of the characters.
* The array does not need to be initialized.
* The index map will result in indexMap[logicalIndex]==visualIndex
.
*/
U_CAPI void U_EXPORT2
ubidi_reorderLogical(const UBiDiLevel *levels, UTextOffset length, UTextOffset *indexMap);
/**
* This is a convenience function that does not use a UBiDi object.
* It is intended to be used for when an application has determined the levels
* of objects (character sequences) and just needs to have them reordered (L2).
* This is equivalent to using ubidi_getVisualMap
on a
* UBiDi
object.
*
* @param levels is an array with length
levels that have been determined by
* the application.
*
* @param length is the number of levels in the array, or, semantically,
* the number of objects to be reordered.
* It must be length>0
.
*
* @param indexMap is a pointer to an array of length
* indexes which will reflect the reordering of the characters.
* The array does not need to be initialized.
* The index map will result in indexMap[visualIndex]==logicalIndex
.
*/
U_CAPI void U_EXPORT2
ubidi_reorderVisual(const UBiDiLevel *levels, UTextOffset length, UTextOffset *indexMap);
/**
* Invert an index map.
* The one-to-one index mapping of the first map is inverted and written to
* the second one.
*
* @param srcMap is an array with length
indexes
* which define the original mapping.
*
* @param destMap is an array with length
indexes
* which will be filled with the inverse mapping.
*
* @param length is the length of each array.
*/
U_CAPI void U_EXPORT2
ubidi_invertMap(const UTextOffset *srcMap, UTextOffset *destMap, UTextOffset length);
/**
* @name Sample code for the ICU BIDI API
*
*
The basic assumptions are:
** #include "ubidi.h" * * typedef enum { * styleNormal=0, styleSelected=1, * styleBold=2, styleItalics=4, * styleSuper=8, styleSub=16 * } Style; * * typedef struct { UTextOffset limit; Style style; } StyleRun; * * int getTextWidth(const UChar *text, UTextOffset start, UTextOffset limit, * const StyleRun *styleRuns, int styleRunCount); * * // set *pLimit and *pStyleRunLimit for a line * // from text[start] and from styleRuns[styleRunStart] * // using ubidi_getLogicalRun(para, ...) * void getLineBreak(const UChar *text, UTextOffset start, UTextOffset *pLimit, * UBiDi *para, * const StyleRun *styleRuns, int styleRunStart, int *pStyleRunLimit, * int *pLineWidth); * * // render runs on a line sequentially, always from left to right * * // prepare rendering a new line * void startLine(UBiDiDirection textDirection, int lineWidth); * * // render a run of text and advance to the right by the run width * // the text[start..limit-1] is always in logical order * void renderRun(const UChar *text, UTextOffset start, UTextOffset limit, * UBiDiDirection textDirection, Style style); * * // We could compute a cross-product * // from the style runs with the directional runs * // and then reorder it. * // Instead, here we iterate over each run type * // and render the intersections - * // with shortcuts in simple (and common) cases. * // renderParagraph() is the main function. * * // render a directional run with * // (possibly) multiple style runs intersecting with it * void renderDirectionalRun(const UChar *text, * UTextOffset start, UTextOffset limit, * UBiDiDirection direction, * const StyleRun *styleRuns, int styleRunCount) { * int i; * * // iterate over style runs * if(direction==UBIDI_LTR) { * int styleLimit; * * for(i=0; i<styleRunCount; ++i) { * styleLimit=styleRun[i].limit; * if(start<styleLimit) { * if(styleLimit>limit) { styleLimit=limit; } * renderRun(text, start, styleLimit, * direction, styleRun[i].style); * if(styleLimit==limit) { break; } * start=styleLimit; * } * } * } else { * int styleStart; * * for(i=styleRunCount-1; i>=0; --i) { * if(i>0) { * styleStart=styleRun[i-1].limit; * } else { * styleStart=0; * } * if(limit>=styleStart) { * if(styleStart<start) { styleStart=start; } * renderRun(text, styleStart, limit, * direction, styleRun[i].style); * if(styleStart==start) { break; } * limit=styleStart; * } * } * } * } * * // the line object represents text[start..limit-1] * void renderLine(UBiDi *line, const UChar *text, * UTextOffset start, UTextOffset limit, * const StyleRun *styleRuns, int styleRunCount) { * UBiDiDirection direction=ubidi_getDirection(line); * if(direction!=UBIDI_MIXED) { * // unidirectional * if(styleRunCount<=1) { * renderRun(text, start, limit, direction, styleRuns[0].style); * } else { * renderDirectionalRun(text, start, limit, * direction, styleRuns, styleRunCount); * } * } else { * // mixed-directional * UTextOffset count, i, length; * UBiDiLevel level; * * count=ubidi_countRuns(para, pErrorCode); * if(U_SUCCESS(*pErrorCode)) { * if(styleRunCount<=1) { * Style style=styleRuns[0].style; * * // iterate over directional runs * for(i=0; i<count; ++i) { * direction=ubidi_getVisualRun(para, i, &start, &length); * renderRun(text, start, start+length, direction, style); * } * } else { * UTextOffset j; * * // iterate over both directional and style runs * for(i=0; i<count; ++i) { * direction=ubidi_getVisualRun(line, i, &start, &length); * renderDirectionalRun(text, start, start+length, * direction, styleRuns, styleRunCount); * } * } * } * } * } * * void renderParagraph(const UChar *text, UTextOffset length, * UBiDiDirection textDirection, * const StyleRun *styleRuns, int styleRunCount, * int lineWidth, * UErrorCode *pErrorCode) { * UBiDi *para; * * if(pErrorCode==NULL || U_FAILURE(*pErrorCode) || length<=0) { * return; * } * * para=ubidi_openSized(length, 0, pErrorCode); * if(para==NULL) { return; } * * ubidi_setPara(para, text, length, * textDirection ? UBIDI_DEFAULT_RTL : UBIDI_DEFAULT_LTR, * NULL, pErrorCode); * if(U_SUCCESS(*pErrorCode)) { * UBiDiLevel paraLevel=1&ubidi_getParaLevel(para); * StyleRun styleRun={ length, styleNormal }; * int width; * * if(styleRuns==NULL || styleRunCount<=0) { * styleRunCount=1; * styleRuns=&styleRun; * } * * // assume styleRuns[styleRunCount-1].limit>=length * * width=getTextWidth(text, 0, length, styleRuns, styleRunCount); * if(width<=lineWidth) { * // everything fits onto one line * * // prepare rendering a new line from either left or right * startLine(paraLevel, width); * * renderLine(para, text, 0, length, * styleRuns, styleRunCount); * } else { * UBiDi *line; * * // we need to render several lines * line=ubidi_openSized(length, 0, pErrorCode); * if(line!=NULL) { * UTextOffset start=0, limit; * int styleRunStart=0, styleRunLimit; * * for(;;) { * limit=length; * styleRunLimit=styleRunCount; * getLineBreak(text, start, &limit, para, * styleRuns, styleRunStart, &styleRunLimit, * &width); * ubidi_setLine(para, start, limit, line, pErrorCode); * if(U_SUCCESS(*pErrorCode)) { * // prepare rendering a new line * // from either left or right * startLine(paraLevel, width); * * renderLine(line, text, start, limit, * styleRuns+styleRunStart, * styleRunLimit-styleRunStart); * } * if(limit==length) { break; } * start=limit; * styleRunStart=styleRunLimit-1; * if(start>=styleRuns[styleRunStart].limit) { * ++styleRunStart; * } * } * * ubidi_close(line); * } * } * } * * ubidi_close(para); * } **/ BIDI_SAMPLE_CODE /*@{*/ /*@}*/ /*@}*/ #endif