* * Note: Libraries that perform a bidirectional algorithm and * reorder strings accordingly are sometimes called "Storage Layout Engines". * ICU's Bidi and shaping (u_shapeArabic()) APIs can be used at the core of such * "Storage Layout Engines". * *
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 * * *
The basic assumptions are:
*
* \code
*#include "unicode/ubidi.h"
*
*typedef enum {
* styleNormal=0, styleSelected=1,
* styleBold=2, styleItalics=4,
* styleSuper=8, styleSub=16
*} Style;
*
*typedef struct { int32_t limit; Style style; } StyleRun;
*
*int getTextWidth(const UChar *text, int32_t start, int32_t 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, int32_t start, int32_t *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, int32_t start, int32_t 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,
* int32_t start, int32_t limit,
* UBiDiDirection direction,
* const StyleRun *styleRuns, int styleRunCount) {
* int i;
*
* // iterate over style runs
* if(direction==UBIDI_LTR) {
* int styleLimit;
*
* for(i=0; ilimit) { 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=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) {
* int32_t 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);
*}
*\endcode
*
*/
/*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
* pseudo-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.
*
* Note: The numeric values of the related constants will not change:
* They are tied to the use of 7-bit byte values (plus the override bit)
* and of the UBiDiLevel=uint8_t data type in this API.
*
* @see UBIDI_DEFAULT_LTR
* @see UBIDI_DEFAULT_RTL
* @see UBIDI_LEVEL_OVERRIDE
* @see UBIDI_MAX_EXPLICIT_LEVEL
* @stable ICU 2.0
*/
typedef uint8_t UBiDiLevel;
/** Paragraph level setting.
* * Constant indicating that the base direction depends on the first strong * directional character in the text according to the Unicode Bidirectional * Algorithm. If no strong directional character is present, * then set the paragraph level to 0 (left-to-right).
*
* If this value is used in conjunction with reordering modes
* UBIDI_REORDER_INVERSE_LIKE_DIRECT or
* UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL, the text to reorder
* is assumed to be visual LTR, and the text after reordering is required
* to be the corresponding logical string with appropriate contextual
* direction. The direction of the result string will be RTL if either
* the righmost or leftmost strong character of the source text is RTL
* or Arabic Letter, the direction will be LTR otherwise.
*
* If reordering option UBIDI_OPTION_INSERT_MARKS is set, an RLM may
* be added at the beginning of the result string to ensure round trip
* (that the result string, when reordered back to visual, will produce
* the original source text).
* @see UBIDI_REORDER_INVERSE_LIKE_DIRECT
* @see UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL
* @stable ICU 2.0
*/
#define UBIDI_DEFAULT_LTR 0xfe
/** Paragraph level setting.
* * Constant indicating that the base direction depends on the first strong * directional character in the text according to the Unicode Bidirectional * Algorithm. If no strong directional character is present, * then set the paragraph level to 1 (right-to-left).
*
* If this value is used in conjunction with reordering modes
* UBIDI_REORDER_INVERSE_LIKE_DIRECT or
* UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL, the text to reorder
* is assumed to be visual LTR, and the text after reordering is required
* to be the corresponding logical string with appropriate contextual
* direction. The direction of the result string will be RTL if either
* the righmost or leftmost strong character of the source text is RTL
* or Arabic Letter, or if the text contains no strong character;
* the direction will be LTR otherwise.
*
* If reordering option UBIDI_OPTION_INSERT_MARKS is set, an RLM may
* be added at the beginning of the result string to ensure round trip
* (that the result string, when reordered back to visual, will produce
* the original source text).
* @see UBIDI_REORDER_INVERSE_LIKE_DIRECT
* @see UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL
* @stable ICU 2.0
*/
#define UBIDI_DEFAULT_RTL 0xff
/**
* Maximum explicit embedding level.
* Same as the max_depth value in the
* Unicode Bidirectional Algorithm.
* (The maximum resolved level can be up to UBIDI_MAX_EXPLICIT_LEVEL+1).
* @stable ICU 2.0
*/
#define UBIDI_MAX_EXPLICIT_LEVEL 125
/** Bit flag for level input.
* Overrides directional properties.
* @stable ICU 2.0
*/
#define UBIDI_LEVEL_OVERRIDE 0x80
/**
* Special value which can be returned by the mapping functions when a logical
* index has no corresponding visual index or vice-versa. This may happen
* for the logical-to-visual mapping of a Bidi control when option
* #UBIDI_OPTION_REMOVE_CONTROLS is specified. This can also happen
* for the visual-to-logical mapping of a Bidi mark (LRM or RLM) inserted
* by option #UBIDI_OPTION_INSERT_MARKS.
* @see ubidi_getVisualIndex
* @see ubidi_getVisualMap
* @see ubidi_getLogicalIndex
* @see ubidi_getLogicalMap
* @stable ICU 3.6
*/
#define UBIDI_MAP_NOWHERE (-1)
/**
* UBiDiDirection values indicate the text direction.
* @stable ICU 2.0
*/
enum UBiDiDirection {
/** Left-to-right text. This is a 0 value.
*
ubidi_getDirection(), it means
* that the source string contains no right-to-left characters, or
* that the source string is empty and the paragraph level is even.
* ubidi_getBaseDirection(), it
* means that the first strong character of the source string has
* a left-to-right direction.
* ubidi_getDirection(), it means
* that the source string contains no left-to-right characters, or
* that the source string is empty and the paragraph level is odd.
* ubidi_getBaseDirection(), it
* means that the first strong character of the source string has
* a right-to-left direction.
* As return value for ubidi_getDirection(), it means
* that the source string contains both left-to-right and
* right-to-left characters.
* @stable ICU 2.0
*/
UBIDI_MIXED,
/** No strongly directional text.
*
As return value for ubidi_getBaseDirection(), it means
* that the source string is missing or empty, or contains neither left-to-right
* nor right-to-left characters.
* @stable ICU 4.6
*/
UBIDI_NEUTRAL
};
/** @stable ICU 2.0 */
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 (or multiple paragraphs) * of text with Bidi-algorithm-related details, or about one line of * such a paragraph.
* Reordering can be done on a line, or on one or more paragraphs which are
* then interpreted each as one single line.
* @stable ICU 2.0
*/
struct UBiDi;
/** @stable ICU 2.0 */
typedef struct UBiDi UBiDi;
/**
* Allocate a UBiDi structure.
* Such an object is initially empty. It is assigned
* the Bidi properties of a piece of text containing one or more paragraphs
* by ubidi_setPara()
* or the Bidi properties of a line within a paragraph by
* ubidi_setLine().
* This object can be reused for as long as it is not deallocated
* by calling ubidi_close().
* ubidi_setPara() and ubidi_setLine() will allocate
* additional memory for internal structures as necessary.
*
* @return An empty UBiDi object.
* @stable ICU 2.0
*/
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 text 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.
*
* @return An empty UBiDi object with preallocated memory.
* @stable ICU 2.0
*/
U_CAPI UBiDi * U_EXPORT2
ubidi_openSized(int32_t maxLength, int32_t maxRunCount, UErrorCode *pErrorCode);
/**
* ubidi_close() must be called to free the memory
* associated with a UBiDi object.
*
* Important:
* A parent UBiDi object must not be destroyed or reused if
* it still has children.
* If a UBiDi object has become the child
* of another one (its parent) by 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
* @stable ICU 2.0
*/
U_CAPI void U_EXPORT2
ubidi_close(UBiDi *pBiDi);
#if U_SHOW_CPLUSPLUS_API
U_NAMESPACE_BEGIN
/**
* \class LocalUBiDiPointer
* "Smart pointer" class, closes a UBiDi via ubidi_close().
* For most methods see the LocalPointerBase base class.
*
* @see LocalPointerBase
* @see LocalPointer
* @stable ICU 4.4
*/
U_DEFINE_LOCAL_OPEN_POINTER(LocalUBiDiPointer, UBiDi, ubidi_close);
U_NAMESPACE_END
#endif
/**
* Modify the operation of the Bidi algorithm such that it
* approximates an "inverse Bidi" algorithm. This function
* must be called before ubidi_setPara().
*
*
The normal operation of the Bidi algorithm as described * in the Unicode Technical Report is to take text stored in logical * (keyboard, typing) order and to determine the reordering of it for visual * rendering. * Some legacy systems store text in visual order, and for operations * with standard, Unicode-based algorithms, the text needs to be transformed * to logical order. This is effectively the inverse algorithm of the * described Bidi algorithm. Note that there is no standard algorithm for * this "inverse Bidi" and that the current implementation provides only an * approximation of "inverse Bidi".
* *With isInverse set to true,
* this function changes the behavior of some of the subsequent functions
* in a way that they can be used for the inverse Bidi algorithm.
* Specifically, runs of text with numeric characters will be treated in a
* special way and may need to be surrounded with LRM characters when they are
* written in reordered sequence.
Output runs should be retrieved using ubidi_getVisualRun().
* Since the actual input for "inverse Bidi" is visually ordered text and
* ubidi_getVisualRun() gets the reordered runs, these are actually
* the runs of the logically ordered output.
Calling this function with argument isInverse set to
* true is equivalent to calling
* ubidi_setReorderingMode with argument
* reorderingMode
* set to #UBIDI_REORDER_INVERSE_NUMBERS_AS_L.
* Calling this function with argument isInverse set to
* false is equivalent to calling
* ubidi_setReorderingMode with argument
* reorderingMode
* set to #UBIDI_REORDER_DEFAULT.
*
* @param pBiDi is a UBiDi object.
*
* @param isInverse specifies "forward" or "inverse" Bidi operation.
*
* @see ubidi_setPara
* @see ubidi_writeReordered
* @see ubidi_setReorderingMode
* @stable ICU 2.0
*/
U_CAPI void U_EXPORT2
ubidi_setInverse(UBiDi *pBiDi, UBool isInverse);
/**
* Is this Bidi object set to perform the inverse Bidi algorithm?
*
Note: calling this function after setting the reordering mode with
* ubidi_setReorderingMode will return true if the
* reordering mode was set to #UBIDI_REORDER_INVERSE_NUMBERS_AS_L,
* false for all other values.
UBiDi object.
* @return true if the Bidi object is set to perform the inverse Bidi algorithm
* by handling numbers as L.
*
* @see ubidi_setInverse
* @see ubidi_setReorderingMode
* @stable ICU 2.0
*/
U_CAPI UBool U_EXPORT2
ubidi_isInverse(UBiDi *pBiDi);
/**
* Specify whether block separators must be allocated level zero,
* so that successive paragraphs will progress from left to right.
* This function must be called before ubidi_setPara().
* Paragraph separators (B) may appear in the text. Setting them to level zero
* means that all paragraph separators (including one possibly appearing
* in the last text position) are kept in the reordered text after the text
* that they follow in the source text.
* When this feature is not enabled, a paragraph separator at the last
* position of the text before reordering will go to the first position
* of the reordered text when the paragraph level is odd.
*
* @param pBiDi is a UBiDi object.
*
* @param orderParagraphsLTR specifies whether paragraph separators (B) must
* receive level 0, so that successive paragraphs progress from left to right.
*
* @see ubidi_setPara
* @stable ICU 3.4
*/
U_CAPI void U_EXPORT2
ubidi_orderParagraphsLTR(UBiDi *pBiDi, UBool orderParagraphsLTR);
/**
* Is this Bidi object set to allocate level 0 to block separators so that
* successive paragraphs progress from left to right?
*
* @param pBiDi is a UBiDi object.
* @return true if the Bidi object is set to allocate level 0 to block
* separators.
*
* @see ubidi_orderParagraphsLTR
* @stable ICU 3.4
*/
U_CAPI UBool U_EXPORT2
ubidi_isOrderParagraphsLTR(UBiDi *pBiDi);
/**
* UBiDiReorderingMode values indicate which variant of the Bidi
* algorithm to use.
*
* @see ubidi_setReorderingMode
* @stable ICU 3.6
*/
typedef enum UBiDiReorderingMode {
/** Regular Logical to Visual Bidi algorithm according to Unicode.
* This is a 0 value.
* @stable ICU 3.6 */
UBIDI_REORDER_DEFAULT = 0,
/** Logical to Visual algorithm which handles numbers in a way which
* mimics the behavior of Windows XP.
* @stable ICU 3.6 */
UBIDI_REORDER_NUMBERS_SPECIAL,
/** Logical to Visual algorithm grouping numbers with adjacent R characters
* (reversible algorithm).
* @stable ICU 3.6 */
UBIDI_REORDER_GROUP_NUMBERS_WITH_R,
/** Reorder runs only to transform a Logical LTR string to the Logical RTL
* string with the same display, or vice-versa.#UBIDI_OPTION_INSERT_MARKS, some Bidi controls in the source
* text may be removed and other controls may be added to produce the
* minimum combination which has the required display.
* @stable ICU 3.6 */
UBIDI_REORDER_RUNS_ONLY,
/** Visual to Logical algorithm which handles numbers like L
* (same algorithm as selected by ubidi_setInverse(true).
* @see ubidi_setInverse
* @stable ICU 3.6 */
UBIDI_REORDER_INVERSE_NUMBERS_AS_L,
/** Visual to Logical algorithm equivalent to the regular Logical to Visual
* algorithm.
* @stable ICU 3.6 */
UBIDI_REORDER_INVERSE_LIKE_DIRECT,
/** Inverse Bidi (Visual to Logical) algorithm for the
* UBIDI_REORDER_NUMBERS_SPECIAL Bidi algorithm.
* @stable ICU 3.6 */
UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL,
#ifndef U_HIDE_DEPRECATED_API
/**
* Number of values for reordering mode.
* @deprecated ICU 58 The numeric value may change over time, see ICU ticket #12420.
*/
UBIDI_REORDER_COUNT
#endif // U_HIDE_DEPRECATED_API
} UBiDiReorderingMode;
/**
* Modify the operation of the Bidi algorithm such that it implements some
* variant to the basic Bidi algorithm or approximates an "inverse Bidi"
* algorithm, depending on different values of the "reordering mode".
* This function must be called before ubidi_setPara(), and stays
* in effect until called again with a different argument.
*
* The normal operation of the Bidi algorithm as described * in the Unicode Standard Annex #9 is to take text stored in logical * (keyboard, typing) order and to determine how to reorder it for visual * rendering.
* *With the reordering mode set to a value other than
* #UBIDI_REORDER_DEFAULT, this function changes the behavior of
* some of the subsequent functions in a way such that they implement an
* inverse Bidi algorithm or some other algorithm variants.
Some legacy systems store text in visual order, and for operations * with standard, Unicode-based algorithms, the text needs to be transformed * into logical order. This is effectively the inverse algorithm of the * described Bidi algorithm. Note that there is no standard algorithm for * this "inverse Bidi", so a number of variants are implemented here.
* *In other cases, it may be desirable to emulate some variant of the * Logical to Visual algorithm (e.g. one used in MS Windows), or perform a * Logical to Logical transformation.
* *#UBIDI_REORDER_DEFAULT,
* the standard Bidi Logical to Visual algorithm is applied.#UBIDI_REORDER_NUMBERS_SPECIAL,
* the algorithm used to perform Bidi transformations when calling
* ubidi_setPara should approximate the algorithm used in
* Microsoft Windows XP rather than strictly conform to the Unicode Bidi
* algorithm.
* #UBIDI_REORDER_GROUP_NUMBERS_WITH_R,
* numbers located between LTR text and RTL text are associated with the RTL
* text. For instance, an LTR paragraph with content "abc 123 DEF" (where
* upper case letters represent RTL characters) will be transformed to
* "abc FED 123" (and not "abc 123 FED"), "DEF 123 abc" will be transformed
* to "123 FED abc" and "123 FED abc" will be transformed to "DEF 123 abc".
* This makes the algorithm reversible and makes it useful when round trip
* (from visual to logical and back to visual) must be achieved without
* adding LRM characters. However, this is a variation from the standard
* Unicode Bidi algorithm.#UBIDI_REORDER_RUNS_ONLY,
* a "Logical to Logical" transformation must be performed:
* paraLevel
* in ubidi_setPara) is even, the source text will be handled as
* LTR logical text and will be transformed to the RTL logical text which has
* the same LTR visual display.#UBIDI_REORDER_INVERSE_NUMBERS_AS_L, an "inverse Bidi" algorithm
* is applied.
* Runs of text with numeric characters will be treated like LTR letters and
* may need to be surrounded with LRM characters when they are written in
* reordered sequence (the option #UBIDI_INSERT_LRM_FOR_NUMERIC can
* be used with function ubidi_writeReordered to this end. This
* mode is equivalent to calling ubidi_setInverse() with
* argument isInverse set to true.#UBIDI_REORDER_INVERSE_LIKE_DIRECT, the "direct" Logical to Visual
* Bidi algorithm is used as an approximation of an "inverse Bidi" algorithm.
* This mode is similar to mode #UBIDI_REORDER_INVERSE_NUMBERS_AS_L
* but is closer to the regular Bidi algorithm.
* UBIDI_REORDER_INVERSE_NUMBERS_AS_L.#UBIDI_OPTION_INSERT_MARKS, this mode generally
* adds Bidi marks to the output significantly more sparingly than mode
* #UBIDI_REORDER_INVERSE_NUMBERS_AS_L with option
* #UBIDI_INSERT_LRM_FOR_NUMERIC in calls to
* ubidi_writeReordered.#UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL, the Logical to Visual
* Bidi algorithm used in Windows XP is used as an approximation of an "inverse Bidi" algorithm.
* In all the reordering modes specifying an "inverse Bidi" algorithm
* (i.e. those with a name starting with UBIDI_REORDER_INVERSE),
* output runs should be retrieved using
* ubidi_getVisualRun(), and the output text with
* ubidi_writeReordered(). The caller should keep in mind that in
* "inverse Bidi" modes the input is actually visually ordered text and
* reordered output returned by ubidi_getVisualRun() or
* ubidi_writeReordered() are actually runs or character string
* of logically ordered output.
* For all the "inverse Bidi" modes, the source text should not contain
* Bidi control characters other than LRM or RLM.
Note that option #UBIDI_OUTPUT_REVERSE of
* ubidi_writeReordered has no useful meaning and should not be
* used in conjunction with any value of the reordering mode specifying
* "inverse Bidi" or with value UBIDI_REORDER_RUNS_ONLY.
*
* @param pBiDi is a UBiDi object.
* @param reorderingMode specifies the required variant of the Bidi algorithm.
*
* @see UBiDiReorderingMode
* @see ubidi_setInverse
* @see ubidi_setPara
* @see ubidi_writeReordered
* @stable ICU 3.6
*/
U_CAPI void U_EXPORT2
ubidi_setReorderingMode(UBiDi *pBiDi, UBiDiReorderingMode reorderingMode);
/**
* What is the requested reordering mode for a given Bidi object?
*
* @param pBiDi is a UBiDi object.
* @return the current reordering mode of the Bidi object
* @see ubidi_setReorderingMode
* @stable ICU 3.6
*/
U_CAPI UBiDiReorderingMode U_EXPORT2
ubidi_getReorderingMode(UBiDi *pBiDi);
/**
* UBiDiReorderingOption values indicate which options are
* specified to affect the Bidi algorithm.
*
* @see ubidi_setReorderingOptions
* @stable ICU 3.6
*/
typedef enum UBiDiReorderingOption {
/**
* option value for ubidi_setReorderingOptions:
* disable all the options which can be set with this function
* @see ubidi_setReorderingOptions
* @stable ICU 3.6
*/
UBIDI_OPTION_DEFAULT = 0,
/**
* option bit for ubidi_setReorderingOptions:
* insert Bidi marks (LRM or RLM) when needed to ensure correct result of
* a reordering to a Logical order
*
*
This option must be set or reset before calling
* ubidi_setPara.
This option is significant only with reordering modes which generate * a result with Logical order, specifically:
*#UBIDI_REORDER_RUNS_ONLY#UBIDI_REORDER_INVERSE_NUMBERS_AS_L#UBIDI_REORDER_INVERSE_LIKE_DIRECT#UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIALIf this option is set in conjunction with reordering mode
* #UBIDI_REORDER_INVERSE_NUMBERS_AS_L or with calling
* ubidi_setInverse(true), it implies
* option #UBIDI_INSERT_LRM_FOR_NUMERIC
* in calls to function ubidi_writeReordered().
For other reordering modes, a minimum number of LRM or RLM characters
* will be added to the source text after reordering it so as to ensure
* round trip, i.e. when applying the inverse reordering mode on the
* resulting logical text with removal of Bidi marks
* (option #UBIDI_OPTION_REMOVE_CONTROLS set before calling
* ubidi_setPara() or option #UBIDI_REMOVE_BIDI_CONTROLS
* in ubidi_writeReordered), the result will be identical to the
* source text in the first transformation.
*
*
This option will be ignored if specified together with option
* #UBIDI_OPTION_REMOVE_CONTROLS. It inhibits option
* UBIDI_REMOVE_BIDI_CONTROLS in calls to function
* ubidi_writeReordered() and it implies option
* #UBIDI_INSERT_LRM_FOR_NUMERIC in calls to function
* ubidi_writeReordered() if the reordering mode is
* #UBIDI_REORDER_INVERSE_NUMBERS_AS_L.
ubidi_setReorderingOptions:
* remove Bidi control characters
*
* This option must be set or reset before calling
* ubidi_setPara.
This option nullifies option #UBIDI_OPTION_INSERT_MARKS.
* It inhibits option #UBIDI_INSERT_LRM_FOR_NUMERIC in calls
* to function ubidi_writeReordered() and it implies option
* #UBIDI_REMOVE_BIDI_CONTROLS in calls to that function.
ubidi_setReorderingOptions:
* process the output as part of a stream to be continued
*
* This option must be set or reset before calling
* ubidi_setPara.
This option specifies that the caller is interested in processing large * text object in parts. * The results of the successive calls are expected to be concatenated by the * caller. Only the call for the last part will have this option bit off.
* *When this option bit is on, ubidi_setPara() may process
* less than the full source text in order to truncate the text at a meaningful
* boundary. The caller should call ubidi_getProcessedLength()
* immediately after calling ubidi_setPara() in order to
* determine how much of the source text has been processed.
* Source text beyond that length should be resubmitted in following calls to
* ubidi_setPara. The processed length may be less than
* the length of the source text if a character preceding the last character of
* the source text constitutes a reasonable boundary (like a block separator)
* for text to be continued.
* If the last character of the source text constitutes a reasonable
* boundary, the whole text will be processed at once.
* If nowhere in the source text there exists
* such a reasonable boundary, the processed length will be zero.
* The caller should check for such an occurrence and do one of the following:
*
UBIDI_OPTION_STREAMING.When the UBIDI_OPTION_STREAMING option is used,
* it is recommended to call ubidi_orderParagraphsLTR() with
* argument orderParagraphsLTR set to true before
* calling ubidi_setPara so that later paragraphs may be
* concatenated to previous paragraphs on the right.
UBiDi object.
* @param reorderingOptions is a combination of zero or more of the following
* options:
* #UBIDI_OPTION_DEFAULT, #UBIDI_OPTION_INSERT_MARKS,
* #UBIDI_OPTION_REMOVE_CONTROLS, #UBIDI_OPTION_STREAMING.
*
* @see ubidi_getReorderingOptions
* @stable ICU 3.6
*/
U_CAPI void U_EXPORT2
ubidi_setReorderingOptions(UBiDi *pBiDi, uint32_t reorderingOptions);
/**
* What are the reordering options applied to a given Bidi object?
*
* @param pBiDi is a UBiDi object.
* @return the current reordering options of the Bidi object
* @see ubidi_setReorderingOptions
* @stable ICU 3.6
*/
U_CAPI uint32_t U_EXPORT2
ubidi_getReorderingOptions(UBiDi *pBiDi);
/**
* Set the context before a call to ubidi_setPara().* * ubidi_setPara() computes the left-right directionality for a given piece * of text which is supplied as one of its arguments. Sometimes this piece * of text (the "main text") should be considered in context, because text * appearing before ("prologue") and/or after ("epilogue") the main text * may affect the result of this computation.
* * This function specifies the prologue and/or the epilogue for the next * call to ubidi_setPara(). The characters specified as prologue and * epilogue should not be modified by the calling program until the call * to ubidi_setPara() has returned. If successive calls to ubidi_setPara() * all need specification of a context, ubidi_setContext() must be called * before each call to ubidi_setPara(). In other words, a context is not * "remembered" after the following successful call to ubidi_setPara().
* * If a call to ubidi_setPara() specifies UBIDI_DEFAULT_LTR or * UBIDI_DEFAULT_RTL as paraLevel and is preceded by a call to * ubidi_setContext() which specifies a prologue, the paragraph level will * be computed taking in consideration the text in the prologue.
* * When ubidi_setPara() is called without a previous call to * ubidi_setContext, the main text is handled as if preceded and followed * by strong directional characters at the current paragraph level. * Calling ubidi_setContext() with specification of a prologue will change * this behavior by handling the main text as if preceded by the last * strong character appearing in the prologue, if any. * Calling ubidi_setContext() with specification of an epilogue will change * the behavior of ubidi_setPara() by handling the main text as if followed * by the first strong character or digit appearing in the epilogue, if any.
*
* Note 1: if ubidi_setContext is called repeatedly without
* calling ubidi_setPara, the earlier calls have no effect,
* only the last call will be remembered for the next call to
* ubidi_setPara.
*
* Note 2: calling ubidi_setContext(pBiDi, NULL, 0, NULL, 0, &errorCode)
* cancels any previous setting of non-empty prologue or epilogue.
* The next call to ubidi_setPara() will process no
* prologue or epilogue.
*
* Note 3: users must be aware that even after setting the context
* before a call to ubidi_setPara() to perform e.g. a logical to visual
* transformation, the resulting string may not be identical to what it
* would have been if all the text, including prologue and epilogue, had
* been processed together.
* Example (upper case letters represent RTL characters):
* prologue = "abc DE"
* epilogue = none
* main text = "FGH xyz"
* paraLevel = UBIDI_LTR
* display without prologue = "HGF xyz"
* ("HGF" is adjacent to "xyz")
* display with prologue = "abc HGFED xyz"
* ("HGF" is not adjacent to "xyz")
*
* @param pBiDi is a paragraph UBiDi object.
*
* @param prologue is a pointer to the text which precedes the text that
* will be specified in a coming call to ubidi_setPara().
* If there is no prologue to consider, then proLength
* must be zero and this pointer can be NULL.
*
* @param proLength is the length of the prologue; if proLength==-1
* then the prologue must be zero-terminated.
* Otherwise proLength must be >= 0. If proLength==0, it means
* that there is no prologue to consider.
*
* @param epilogue is a pointer to the text which follows the text that
* will be specified in a coming call to ubidi_setPara().
* If there is no epilogue to consider, then epiLength
* must be zero and this pointer can be NULL.
*
* @param epiLength is the length of the epilogue; if epiLength==-1
* then the epilogue must be zero-terminated.
* Otherwise epiLength must be >= 0. If epiLength==0, it means
* that there is no epilogue to consider.
*
* @param pErrorCode must be a valid pointer to an error code value.
*
* @see ubidi_setPara
* @stable ICU 4.8
*/
U_CAPI void U_EXPORT2
ubidi_setContext(UBiDi *pBiDi,
const UChar *prologue, int32_t proLength,
const UChar *epilogue, int32_t epiLength,
UErrorCode *pErrorCode);
/**
* Perform the Unicode Bidi algorithm. It is defined in the
* Unicode Standard Annex #9,
* version 13,
* also described in The Unicode Standard, Version 4.0 .
* * This function takes a piece of plain text containing one or more paragraphs, * with or without externally specified embedding levels from styled * text and computes the left-right-directionality of each character.
*
* If the entire text is all of the same directionality, 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 can be composed of multiple paragraphs. Occurrence of a block
* separator in the text terminates a paragraph, and whatever comes next starts
* a new paragraph. The exception to this rule is when a Carriage Return (CR)
* is followed by a Line Feed (LF). Both CR and LF are block separators, but
* in that case, the pair of characters is considered as terminating the
* preceding paragraph, and a new paragraph will be started by a character
* coming after the LF.
*
* @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 text that the Bidi algorithm will be performed on.
* This pointer is stored in the UBiDi object and can be retrieved
* with ubidi_getText().
* Note: 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 text;
* 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 the text contains multiple
* paragraphs, the paragraph level shall be determined separately for
* each paragraph; if a paragraph does not include any 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.
* Aside from that bit, it must be
* paraLevel<=embeddingLevels[]<=UBIDI_MAX_EXPLICIT_LEVEL,
* except that level 0 is always allowed.
* Level 0 for a paragraph separator prevents reordering of paragraphs;
* this only works reliably if #UBIDI_LEVEL_OVERRIDE
* is also set for paragraph separators.
* Level 0 for other characters is treated as a wildcard
* and is lifted up to the resolved level of the surrounding paragraph.
* 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.
* Note: the embeddingLevels array must be
* at least length long.
* This pointer can be NULL if this
* value is not necessary.
*
* @param pErrorCode must be a valid pointer to an error code value.
* @stable ICU 2.0
*/
U_CAPI void U_EXPORT2
ubidi_setPara(UBiDi *pBiDi, const UChar *text, int32_t length,
UBiDiLevel paraLevel, UBiDiLevel *embeddingLevels,
UErrorCode *pErrorCode);
/**
* ubidi_setLine() 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 piece of text containing one or more paragraphs,
* and by specifying a range of indexes in this text.
* In the new line object, the indexes will range from 0 to limit-start-1.
*
* This is used after calling ubidi_setPara()
* for a piece of text, and after line-breaking on that text.
* It is not necessary if each 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.
*
* The text pointer that was stored in
*
* @param pBiDi is the paragraph or line
*
* @param pBiDi is the paragraph
*
* Note that this function may allocate memory under some
* circumstances, unlike
* This is especially useful for line-breaking on a paragraph.
*
* @param pBiDi is the paragraph or line
*
* Use of
*
* The value returned may be
* When the visual output is altered by using options of
*
* Note that in right-to-left runs, this mapping places
* second surrogates before first ones (which is generally a bad idea)
* and combining characters before base characters.
* Use of
*
* The value returned may be
* This is the inverse function to
* When the visual output is altered by using options of
*
* Some values in the map may be
* When the visual output is altered by using options of
*
* Note that in right-to-left runs, this mapping places
* second surrogates before first ones (which is generally a bad idea)
* and combining characters before base characters.
* Use of
* Some values in the map may be
* When the visual output is altered by using options of
*
* The index map will result in
* The index map will result in This option does not imply corresponding adjustment of the index
* mappings. This option does not imply corresponding adjustment of the index
* mappings. This has the same effect as calling Usually, the function pointer will be propagated to a If a This may be useful for assigning Bidi classes to PUA characters, or
* for special application needs. For instance, an application may want to
* handle all spaces like L or R characters (according to the base direction)
* when creating the visual ordering of logical lines which are part of a report
* organized in columns: there should not be interaction between adjacent
* cells.
*
* @param pBiDi is the paragraph pParaBiDi is also copied,
* and start is added to it so that it points to the beginning of the
* line for this object.
*
* @param pParaBiDi is the parent paragraph object. It must have been set
* by a successful call to ubidi_setPara.
*
* @param start is the line's first index into the text.
*
* @param limit is just behind the line's last index into the text
* (its last index +1).
* It must be 0<=startUBiDi object.
*
* @return a value of UBIDI_LTR, UBIDI_RTL
* or UBIDI_MIXED
* that indicates if the entire text
* represented by this object is unidirectional,
* and which direction, or if it is mixed-directional.
* Note - The value UBIDI_NEUTRAL is never returned from this method.
*
* @see UBiDiDirection
* @stable ICU 2.0
*/
U_CAPI UBiDiDirection U_EXPORT2
ubidi_getDirection(const UBiDi *pBiDi);
/**
* Gets the base direction of the text provided according
* to the Unicode Bidirectional Algorithm. The base direction
* is derived from the first character in the string with bidirectional
* character type L, R, or AL. If the first such character has type L,
* UBIDI_LTR is returned. If the first such character has
* type R or AL, UBIDI_RTL is returned. If the string does
* not contain any character of these types, then
* UBIDI_NEUTRAL is returned.
*
* This is a lightweight function for use when only the base direction
* is needed and no further bidi processing of the text is needed.
*
* @param text is a pointer to the text whose base
* direction is needed.
* Note: the text must be (at least) @c length long.
*
* @param length is the length of the text;
* if length==-1 then the text
* must be zero-terminated.
*
* @return UBIDI_LTR, UBIDI_RTL,
* UBIDI_NEUTRAL
*
* @see UBiDiDirection
* @stable ICU 4.6
*/
U_CAPI UBiDiDirection U_EXPORT2
ubidi_getBaseDirection(const UChar *text, int32_t length );
/**
* Get the pointer to the text.
*
* @param pBiDi is the paragraph or line UBiDi object.
*
* @return The pointer to the text that the UBiDi object was created for.
*
* @see ubidi_setPara
* @see ubidi_setLine
* @stable ICU 2.0
*/
U_CAPI const UChar * U_EXPORT2
ubidi_getText(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.
* @stable ICU 2.0
*/
U_CAPI int32_t 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. If there are multiple paragraphs, their
* level may vary if the required paraLevel is UBIDI_DEFAULT_LTR or
* UBIDI_DEFAULT_RTL. In that case, the level of the first paragraph
* is returned.
*
* @see UBiDiLevel
* @see ubidi_getParagraph
* @see ubidi_getParagraphByIndex
* @stable ICU 2.0
*/
U_CAPI UBiDiLevel U_EXPORT2
ubidi_getParaLevel(const UBiDi *pBiDi);
/**
* Get the number of paragraphs.
*
* @param pBiDi is the paragraph or line UBiDi object.
*
* @return The number of paragraphs.
* @stable ICU 3.4
*/
U_CAPI int32_t U_EXPORT2
ubidi_countParagraphs(UBiDi *pBiDi);
/**
* Get a paragraph, given a position within the text.
* This function returns information about a paragraph.
* Note: if the paragraph index is known, it is more efficient to
* retrieve the paragraph information using ubidi_getParagraphByIndex().UBiDi object.
*
* @param charIndex is the index of a character within the text, in the
* range [0..ubidi_getProcessedLength(pBiDi)-1].
*
* @param pParaStart will receive the index of the first character of the
* paragraph in the text.
* This pointer can be NULL if this
* value is not necessary.
*
* @param pParaLimit will receive the limit of the paragraph.
* The l-value that you point to here may be the
* same expression (variable) as the one for
* charIndex.
* This pointer can be NULL if this
* value is not necessary.
*
* @param pParaLevel will receive the level of the paragraph.
* This pointer can be NULL if this
* value is not necessary.
*
* @param pErrorCode must be a valid pointer to an error code value.
*
* @return The index of the paragraph containing the specified position.
*
* @see ubidi_getProcessedLength
* @stable ICU 3.4
*/
U_CAPI int32_t U_EXPORT2
ubidi_getParagraph(const UBiDi *pBiDi, int32_t charIndex, int32_t *pParaStart,
int32_t *pParaLimit, UBiDiLevel *pParaLevel,
UErrorCode *pErrorCode);
/**
* Get a paragraph, given the index of this paragraph.
*
* This function returns information about a paragraph.UBiDi object.
*
* @param paraIndex is the number of the paragraph, in the
* range [0..ubidi_countParagraphs(pBiDi)-1].
*
* @param pParaStart will receive the index of the first character of the
* paragraph in the text.
* This pointer can be NULL if this
* value is not necessary.
*
* @param pParaLimit will receive the limit of the paragraph.
* This pointer can be NULL if this
* value is not necessary.
*
* @param pParaLevel will receive the level of the paragraph.
* This pointer can be NULL if this
* value is not necessary.
*
* @param pErrorCode must be a valid pointer to an error code value.
*
* @stable ICU 3.4
*/
U_CAPI void U_EXPORT2
ubidi_getParagraphByIndex(const UBiDi *pBiDi, int32_t paraIndex,
int32_t *pParaStart, int32_t *pParaLimit,
UBiDiLevel *pParaLevel, UErrorCode *pErrorCode);
/**
* Get the level for one character.
*
* @param pBiDi is the paragraph or line UBiDi object.
*
* @param charIndex the index of a character. It must be in the range
* [0..ubidi_getProcessedLength(pBiDi)].
*
* @return The level for the character at charIndex (0 if charIndex is not
* in the valid range).
*
* @see UBiDiLevel
* @see ubidi_getProcessedLength
* @stable ICU 2.0
*/
U_CAPI UBiDiLevel U_EXPORT2
ubidi_getLevelAt(const UBiDi *pBiDi, int32_t charIndex);
/**
* Get an array of levels for each character.ubidi_getLevelAt().
*
* @param pBiDi is the paragraph or line UBiDi object, whose
* text length must be strictly positive.
*
* @param pErrorCode must be a valid pointer to an error code value.
*
* @return The levels array for the text,
* or NULL if an error occurs.
*
* @see UBiDiLevel
* @see ubidi_getProcessedLength
* @stable ICU 2.0
*/
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.UBiDi object.
*
* @param logicalPosition is a logical position within the source text.
*
* @param pLogicalLimit will receive the limit of the corresponding run.
* The l-value that you point to here may be the
* same expression (variable) as the one for
* logicalPosition.
* This pointer can be NULL if this
* value is not necessary.
*
* @param pLevel will receive the level of the corresponding run.
* This pointer can be NULL if this
* value is not necessary.
*
* @see ubidi_getProcessedLength
* @stable ICU 2.0
*/
U_CAPI void U_EXPORT2
ubidi_getLogicalRun(const UBiDi *pBiDi, int32_t logicalPosition,
int32_t *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.
*
* @return The number of runs.
* @stable ICU 2.0
*/
U_CAPI int32_t 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,
* never UBIDI_NEUTRAL.
*
* @see ubidi_countRuns
*
* Example:
*
* \code
* int32_t i, count=ubidi_countRuns(pBiDi),
* logicalStart, visualIndex=0, length;
* for(i=0; i
*
* Note that in right-to-left runs, code like this places
* second surrogates before first ones (which is generally a bad idea)
* and combining characters before base characters.
* ubidi_writeReordered(), optionally with the
* #UBIDI_KEEP_BASE_COMBINING option, can be considered in order
* to avoid these issues.
* @stable ICU 2.0
*/
U_CAPI UBiDiDirection U_EXPORT2
ubidi_getVisualRun(UBiDi *pBiDi, int32_t runIndex,
int32_t *pLogicalStart, int32_t *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.#UBIDI_MAP_NOWHERE if there is no
* visual position because the corresponding text character is a Bidi control
* removed from output by the option #UBIDI_OPTION_REMOVE_CONTROLS.
* ubidi_writeReordered() such as UBIDI_INSERT_LRM_FOR_NUMERIC,
* UBIDI_KEEP_BASE_COMBINING, UBIDI_OUTPUT_REVERSE,
* UBIDI_REMOVE_BIDI_CONTROLS, the visual position returned may not
* be correct. It is advised to use, when possible, reordering options
* such as UBIDI_OPTION_INSERT_MARKS and UBIDI_OPTION_REMOVE_CONTROLS.
* ubidi_writeReordered(), optionally with the
* #UBIDI_KEEP_BASE_COMBINING option can be considered instead
* of using the mapping, in order to avoid these issues.
*
* @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.
*
* @return The visual position of this character.
*
* @see ubidi_getLogicalMap
* @see ubidi_getLogicalIndex
* @see ubidi_getProcessedLength
* @stable ICU 2.0
*/
U_CAPI int32_t U_EXPORT2
ubidi_getVisualIndex(UBiDi *pBiDi, int32_t 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.#UBIDI_MAP_NOWHERE if there is no
* logical position because the corresponding text character is a Bidi mark
* inserted in the output by option #UBIDI_OPTION_INSERT_MARKS.
* ubidi_getVisualIndex().
* ubidi_writeReordered() such as UBIDI_INSERT_LRM_FOR_NUMERIC,
* UBIDI_KEEP_BASE_COMBINING, UBIDI_OUTPUT_REVERSE,
* UBIDI_REMOVE_BIDI_CONTROLS, the logical position returned may not
* be correct. It is advised to use, when possible, reordering options
* such as UBIDI_OPTION_INSERT_MARKS and UBIDI_OPTION_REMOVE_CONTROLS.
*
* @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.
*
* @return The index of this character in the text.
*
* @see ubidi_getVisualMap
* @see ubidi_getVisualIndex
* @see ubidi_getResultLength
* @stable ICU 2.0
*/
U_CAPI int32_t U_EXPORT2
ubidi_getLogicalIndex(UBiDi *pBiDi, int32_t visualIndex, UErrorCode *pErrorCode);
/**
* Get a logical-to-visual index map (array) for the characters in the UBiDi
* (paragraph or line) object.
* #UBIDI_MAP_NOWHERE if the
* corresponding text characters are Bidi controls removed from the visual
* output by the option #UBIDI_OPTION_REMOVE_CONTROLS.
* ubidi_writeReordered() such as UBIDI_INSERT_LRM_FOR_NUMERIC,
* UBIDI_KEEP_BASE_COMBINING, UBIDI_OUTPUT_REVERSE,
* UBIDI_REMOVE_BIDI_CONTROLS, the visual positions returned may not
* be correct. It is advised to use, when possible, reordering options
* such as UBIDI_OPTION_INSERT_MARKS and UBIDI_OPTION_REMOVE_CONTROLS.
* ubidi_writeReordered(), optionally with the
* #UBIDI_KEEP_BASE_COMBINING option can be considered instead
* of using the mapping, in order to avoid these issues.
*
* @param pBiDi is the paragraph or line UBiDi object.
*
* @param indexMap is a pointer to an array of ubidi_getProcessedLength()
* indexes which will reflect the reordering of the characters.
* If option #UBIDI_OPTION_INSERT_MARKS is set, the number
* of elements allocated in indexMap must be no less than
* ubidi_getResultLength().
* 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.
*
* @see ubidi_getVisualMap
* @see ubidi_getVisualIndex
* @see ubidi_getProcessedLength
* @see ubidi_getResultLength
* @stable ICU 2.0
*/
U_CAPI void U_EXPORT2
ubidi_getLogicalMap(UBiDi *pBiDi, int32_t *indexMap, UErrorCode *pErrorCode);
/**
* Get a visual-to-logical index map (array) for the characters in the UBiDi
* (paragraph or line) object.
* #UBIDI_MAP_NOWHERE if the
* corresponding text characters are Bidi marks inserted in the visual output
* by the option #UBIDI_OPTION_INSERT_MARKS.
* ubidi_writeReordered() such as UBIDI_INSERT_LRM_FOR_NUMERIC,
* UBIDI_KEEP_BASE_COMBINING, UBIDI_OUTPUT_REVERSE,
* UBIDI_REMOVE_BIDI_CONTROLS, the logical positions returned may not
* be correct. It is advised to use, when possible, reordering options
* such as UBIDI_OPTION_INSERT_MARKS and UBIDI_OPTION_REMOVE_CONTROLS.
*
* @param pBiDi is the paragraph or line UBiDi object.
*
* @param indexMap is a pointer to an array of ubidi_getResultLength()
* indexes which will reflect the reordering of the characters.
* If option #UBIDI_OPTION_REMOVE_CONTROLS is set, the number
* of elements allocated in indexMap must be no less than
* ubidi_getProcessedLength().
* 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.
*
* @see ubidi_getLogicalMap
* @see ubidi_getLogicalIndex
* @see ubidi_getProcessedLength
* @see ubidi_getResultLength
* @stable ICU 2.0
*/
U_CAPI void U_EXPORT2
ubidi_getVisualMap(UBiDi *pBiDi, int32_t *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.indexMap[logicalIndex]==visualIndex.
* @stable ICU 2.0
*/
U_CAPI void U_EXPORT2
ubidi_reorderLogical(const UBiDiLevel *levels, int32_t length, int32_t *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.indexMap[visualIndex]==logicalIndex.
* @stable ICU 2.0
*/
U_CAPI void U_EXPORT2
ubidi_reorderVisual(const UBiDiLevel *levels, int32_t length, int32_t *indexMap);
/**
* Invert an index map.
* The index mapping of the first map is inverted and written to
* the second one.
*
* @param srcMap is an array with length elements
* which defines the original mapping from a source array containing
* length elements to a destination array.
* Some elements of the source array may have no mapping in the
* destination array. In that case, their value will be
* the special value UBIDI_MAP_NOWHERE.
* All elements must be >=0 or equal to UBIDI_MAP_NOWHERE.
* Some elements may have a value >= length, if the
* destination array has more elements than the source array.
* There must be no duplicate indexes (two or more elements with the
* same value except UBIDI_MAP_NOWHERE).
*
* @param destMap is an array with a number of elements equal to 1 + the highest
* value in srcMap.
* destMap will be filled with the inverse mapping.
* If element with index i in srcMap has a value k different
* from UBIDI_MAP_NOWHERE, this means that element i of
* the source array maps to element k in the destination array.
* The inverse map will have value i in its k-th element.
* For all elements of the destination array which do not map to
* an element in the source array, the corresponding element in the
* inverse map will have a value equal to UBIDI_MAP_NOWHERE.
*
* @param length is the length of each array.
* @see UBIDI_MAP_NOWHERE
* @stable ICU 2.0
*/
U_CAPI void U_EXPORT2
ubidi_invertMap(const int32_t *srcMap, int32_t *destMap, int32_t length);
/** option flags for ubidi_writeReordered() */
/**
* option bit for ubidi_writeReordered():
* keep combining characters after their base characters in RTL runs
*
* @see ubidi_writeReordered
* @stable ICU 2.0
*/
#define UBIDI_KEEP_BASE_COMBINING 1
/**
* option bit for ubidi_writeReordered():
* replace characters with the "mirrored" property in RTL runs
* by their mirror-image mappings
*
* @see ubidi_writeReordered
* @stable ICU 2.0
*/
#define UBIDI_DO_MIRRORING 2
/**
* option bit for ubidi_writeReordered():
* surround the run with LRMs if necessary;
* this is part of the approximate "inverse Bidi" algorithm
*
* ubidi_writeReordered()
* first without this option, and then calling
* ubidi_writeReverse() without mirroring.
* Doing this in the same step is faster and avoids a temporary buffer.
* An example for using this option is output to a character terminal that
* is designed for RTL scripts and stores text in reverse order.ubidi_setPara(). This length may be different from the length
* of the source text if option #UBIDI_OPTION_STREAMING
* has been set.
*
* Note that whenever the length of the text affects the execution or the
* result of a function, it is the processed length which must be considered,
* except for ubidi_setPara (which receives unprocessed source
* text) and ubidi_getLength (which returns the original length
* of the source text).
* In particular, the processed length is the one to consider in the following
* cases:
*
*
*
* @param pBiDi is the paragraph limit argument of
* ubidi_setLinecharIndex argument of
* ubidi_getParagraphcharIndex argument of
* ubidi_getLevelAtubidi_getLevelslogicalStart argument of
* ubidi_getLogicalRunlogicalIndex argument of
* ubidi_getVisualIndex*indexMap argument of
* ubidi_getLogicalMapubidi_writeReorderedUBiDi object.
*
* @return The length of the part of the source text processed by
* the last call to ubidi_setPara.
* @see ubidi_setPara
* @see UBIDI_OPTION_STREAMING
* @stable ICU 3.6
*/
U_CAPI int32_t U_EXPORT2
ubidi_getProcessedLength(const UBiDi *pBiDi);
/**
* Get the length of the reordered text resulting from the last call to
* ubidi_setPara(). This length may be different from the length
* of the source text if option #UBIDI_OPTION_INSERT_MARKS
* or option #UBIDI_OPTION_REMOVE_CONTROLS has been set.
*
* This resulting length is the one to consider in the following cases:
*
*
* Note that this length stays identical to the source text length if
* Bidi marks are inserted or removed using option bits of
* visualIndex argument of
* ubidi_getLogicalIndex*indexMap argument of
* ubidi_getVisualMapubidi_writeReordered, or if option
* #UBIDI_REORDER_INVERSE_NUMBERS_AS_L has been set.
*
* @param pBiDi is the paragraph UBiDi object.
*
* @return The length of the reordered text resulting from
* the last call to ubidi_setPara.
* @see ubidi_setPara
* @see UBIDI_OPTION_INSERT_MARKS
* @see UBIDI_OPTION_REMOVE_CONTROLS
* @stable ICU 3.6
*/
U_CAPI int32_t U_EXPORT2
ubidi_getResultLength(const UBiDi *pBiDi);
U_CDECL_BEGIN
#ifndef U_HIDE_DEPRECATED_API
/**
* Value returned by UBiDiClassCallback callbacks when
* there is no need to override the standard Bidi class for a given code point.
*
* This constant is deprecated; use u_getIntPropertyMaxValue(UCHAR_BIDI_CLASS)+1 instead.
*
* @see UBiDiClassCallback
* @deprecated ICU 58 The numeric value may change over time, see ICU ticket #12420.
*/
#define U_BIDI_CLASS_DEFAULT U_CHAR_DIRECTION_COUNT
#endif // U_HIDE_DEPRECATED_API
/**
* Callback type declaration for overriding default Bidi class values with
* custom ones.
* UBiDi
* object by calling the ubidi_setClassCallback() function;
* then the callback will be invoked by the UBA implementation any time the
* class of a character is to be determined.c if the default class has been overridden, or
* u_getIntPropertyMaxValue(UCHAR_BIDI_CLASS)+1
* if the standard Bidi class value for c is to be used.
* @see ubidi_setClassCallback
* @see ubidi_getClassCallback
* @stable ICU 3.6
*/
typedef UCharDirection U_CALLCONV
UBiDiClassCallback(const void *context, UChar32 c);
U_CDECL_END
/**
* Retrieve the Bidi class for a given code point.
* #UBiDiClassCallback callback is defined and returns a
* value other than u_getIntPropertyMaxValue(UCHAR_BIDI_CLASS)+1,
* that value is used; otherwise the default class determination mechanism is invoked.UBiDi object.
*
* @param c is the code point whose Bidi class must be retrieved.
*
* @return The Bidi class for character c based
* on the given pBiDi instance.
* @see UBiDiClassCallback
* @stable ICU 3.6
*/
U_CAPI UCharDirection U_EXPORT2
ubidi_getCustomizedClass(UBiDi *pBiDi, UChar32 c);
/**
* Set the callback function and callback data used by the UBA
* implementation for Bidi class determination.
* UBiDi object.
*
* @param newFn is the new callback function pointer.
*
* @param newContext is the new callback context pointer. This can be NULL.
*
* @param oldFn fillin: Returns the old callback function pointer. This can be
* NULL.
*
* @param oldContext fillin: Returns the old callback's context. This can be
* NULL.
*
* @param pErrorCode must be a valid pointer to an error code value.
*
* @see ubidi_getClassCallback
* @stable ICU 3.6
*/
U_CAPI void U_EXPORT2
ubidi_setClassCallback(UBiDi *pBiDi, UBiDiClassCallback *newFn,
const void *newContext, UBiDiClassCallback **oldFn,
const void **oldContext, UErrorCode *pErrorCode);
/**
* Get the current callback function used for Bidi class determination.
*
* @param pBiDi is the paragraph UBiDi object.
*
* @param fn fillin: Returns the callback function pointer.
*
* @param context fillin: Returns the callback's private context.
*
* @see ubidi_setClassCallback
* @stable ICU 3.6
*/
U_CAPI void U_EXPORT2
ubidi_getClassCallback(UBiDi *pBiDi, UBiDiClassCallback **fn, const void **context);
/**
* Take a UBiDi object containing the reordering
* information for a piece of text (one or more paragraphs) set by
* ubidi_setPara() or for a line of text set by
* ubidi_setLine() and write a reordered string to the
* destination buffer.
*
* This function preserves the integrity of characters with multiple
* code units and (optionally) combining characters.
* Characters in RTL runs can be replaced by mirror-image characters
* in the destination buffer. Note that "real" mirroring has
* to be done in a rendering engine by glyph selection
* and that for many "mirrored" characters there are no
* Unicode characters as mirror-image equivalents.
* There are also options to insert or remove Bidi control
* characters; see the description of the destSize
* and options parameters and of the option bit flags.
*
* @param pBiDi A pointer to a UBiDi object that
* is set by ubidi_setPara() or
* ubidi_setLine() and contains the reordering
* information for the text that it was defined for,
* as well as a pointer to that text.
* The text was aliased (only the pointer was stored
* without copying the contents) and must not have been modified
* since the ubidi_setPara() call.
*
* @param dest A pointer to where the reordered text is to be copied.
* The source text and dest[destSize]
* must not overlap.
*
* @param destSize The size of the dest buffer,
* in number of UChars.
* If the UBIDI_INSERT_LRM_FOR_NUMERIC
* option is set, then the destination length could be
* as large as
* ubidi_getLength(pBiDi)+2*ubidi_countRuns(pBiDi).
* If the UBIDI_REMOVE_BIDI_CONTROLS option
* is set, then the destination length may be less than
* ubidi_getLength(pBiDi).
* If none of these options is set, then the destination length
* will be exactly ubidi_getProcessedLength(pBiDi).
*
* @param options A bit set of options for the reordering that control
* how the reordered text is written.
* The options include mirroring the characters on a code
* point basis and inserting LRM characters, which is used
* especially for transforming visually stored text
* to logically stored text (although this is still an
* imperfect implementation of an "inverse Bidi" algorithm
* because it uses the "forward Bidi" algorithm at its core).
* The available options are:
* #UBIDI_DO_MIRRORING,
* #UBIDI_INSERT_LRM_FOR_NUMERIC,
* #UBIDI_KEEP_BASE_COMBINING,
* #UBIDI_OUTPUT_REVERSE,
* #UBIDI_REMOVE_BIDI_CONTROLS
*
* @param pErrorCode must be a valid pointer to an error code value.
*
* @return The length of the output string.
*
* @see ubidi_getProcessedLength
* @stable ICU 2.0
*/
U_CAPI int32_t U_EXPORT2
ubidi_writeReordered(UBiDi *pBiDi,
UChar *dest, int32_t destSize,
uint16_t options,
UErrorCode *pErrorCode);
/**
* Reverse a Right-To-Left run of Unicode text.
*
* This function preserves the integrity of characters with multiple
* code units and (optionally) combining characters.
* Characters can be replaced by mirror-image characters
* in the destination buffer. Note that "real" mirroring has
* to be done in a rendering engine by glyph selection
* and that for many "mirrored" characters there are no
* Unicode characters as mirror-image equivalents.
* There are also options to insert or remove Bidi control
* characters.
*
* This function is the implementation for reversing RTL runs as part
* of ubidi_writeReordered(). For detailed descriptions
* of the parameters, see there.
* Since no Bidi controls are inserted here, the output string length
* will never exceed srcLength.
*
* @see ubidi_writeReordered
*
* @param src A pointer to the RTL run text.
*
* @param srcLength The length of the RTL run.
*
* @param dest A pointer to where the reordered text is to be copied.
* src[srcLength] and dest[destSize]
* must not overlap.
*
* @param destSize The size of the dest buffer,
* in number of UChars.
* If the UBIDI_REMOVE_BIDI_CONTROLS option
* is set, then the destination length may be less than
* srcLength.
* If this option is not set, then the destination length
* will be exactly srcLength.
*
* @param options A bit set of options for the reordering that control
* how the reordered text is written.
* See the options parameter in ubidi_writeReordered().
*
* @param pErrorCode must be a valid pointer to an error code value.
*
* @return The length of the output string.
* @stable ICU 2.0
*/
U_CAPI int32_t U_EXPORT2
ubidi_writeReverse(const UChar *src, int32_t srcLength,
UChar *dest, int32_t destSize,
uint16_t options,
UErrorCode *pErrorCode);
/*#define BIDI_SAMPLE_CODE*/
/*@}*/
#endif