// Copyright (C) 2016 and later: Unicode, Inc. and others. // License & terms of use: http://www.unicode.org/copyright.html /* ****************************************************************************** * * Copyright (C) 1999-2013, 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, updated by Matitiahu Allouche */ #ifndef UBIDI_H #define UBIDI_H #include "unicode/utypes.h" #include "unicode/uchar.h" #include "unicode/localpointer.h" /** *\file * \brief C API: Bidi algorithm * *

Bidi algorithm for ICU

* * This is an implementation of the Unicode Bidirectional Algorithm. * The algorithm is defined in the * Unicode Standard Annex #9.

* * 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". * *

General remarks about the API:

* * In functions with an error code parameter, * the 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 * * *

Sample code for the ICU Bidi API

* *
Rendering a paragraph with the ICU Bidi API
* * This is (hypothetical) sample code that illustrates * how the ICU Bidi API could be used to render a paragraph of text. * Rendering code depends highly on the graphics system, * therefore this sample code must make a lot of assumptions, * which may or may not match any existing graphics system's properties. * *

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: *

* * @see ubidi_setPara * *

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 * @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. * (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. *

* @stable ICU 2.0 */ UBIDI_LTR, /** Right-to-left text. This is a 1 value. * * @stable ICU 2.0 */ UBIDI_RTL, /** Mixed-directional text. *

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_STABLE 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_STABLE 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_STABLE 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_STABLE 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.

* * @param pBiDi is a 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_STABLE 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_STABLE 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_STABLE 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 * mimicks 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.
* If this mode is set together with option * #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.

* * * *

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_STABLE 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_STABLE 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:

* * *

If 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.

* * @see ubidi_setReorderingMode * @see ubidi_setReorderingOptions * @stable ICU 3.6 */ UBIDI_OPTION_INSERT_MARKS = 1, /** * option bit for 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.

* * @see ubidi_setReorderingMode * @see ubidi_setReorderingOptions * @stable ICU 3.6 */ UBIDI_OPTION_REMOVE_CONTROLS = 2, /** * option bit for 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: *

* In all cases, this option should be turned off before processing the last * part of the text.

* *

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.

* * @see ubidi_setReorderingMode * @see ubidi_setReorderingOptions * @see ubidi_getProcessedLength * @see ubidi_orderParagraphsLTR * @stable ICU 3.6 */ UBIDI_OPTION_STREAMING = 4 } UBiDiReorderingOption; /** * Specify which of the reordering options * should be applied during Bidi transformations. * * @param pBiDi is a 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_STABLE 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_STABLE 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_STABLE 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 Anned #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.

* Except for that bit, it must be * paraLevel<=embeddingLevels[]<=UBIDI_MAX_EXPLICIT_LEVEL, * with one exception: a level of zero may be specified for a paragraph * separator even if paraLevel>0 when multiple paragraphs * are submitted in the same call to ubidi_setPara().

* 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_STABLE 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 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<=startcontaining paragraph limit. * If the specified line crosses a paragraph boundary, the function * will terminate with error code U_ILLEGAL_ARGUMENT_ERROR. * * @param pLineBiDi is the object that will now represent a line of the text. * * @param pErrorCode must be a valid pointer to an error code value. * * @see ubidi_setPara * @see ubidi_getProcessedLength * @stable ICU 2.0 */ U_STABLE void U_EXPORT2 ubidi_setLine(const UBiDi *pParaBiDi, int32_t start, int32_t limit, UBiDi *pLineBiDi, UErrorCode *pErrorCode); /** * Get the directionality of the text. * * @param pBiDi is the paragraph or line UBiDi 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_STABLE 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_STABLE 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_STABLE 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_STABLE 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_STABLE 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_STABLE 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().

* * @param pBiDi is the paragraph or line 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_STABLE 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.

* * @param pBiDi is the 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_STABLE 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_STABLE UBiDiLevel U_EXPORT2 ubidi_getLevelAt(const UBiDi *pBiDi, int32_t 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, 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_STABLE 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 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_STABLE 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_STABLE 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; i0);
 *     } else {
 *         logicalStart+=length;  // logicalLimit
 *         do { // RTL
 *             show_char(text[--logicalStart], visualIndex++);
 *         } while(--length>0);
 *     }
 * }
 *\endcode
 * 
* * 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. *

* Use of ubidi_writeReordered(), optionally with the * #UBIDI_KEEP_BASE_COMBINING option, can be considered in order * to avoid these issues. * @stable ICU 2.0 */ U_STABLE 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.

* * The value returned may be #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. *

* When the visual output is altered by using options of * 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. *

* 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 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_STABLE 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.

* * The value returned may be #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. *

* This is the inverse function to ubidi_getVisualIndex(). *

* When the visual output is altered by using options of * 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_STABLE 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. *

* Some values in the map may be #UBIDI_MAP_NOWHERE if the * corresponding text characters are Bidi controls removed from the visual * output by the option #UBIDI_OPTION_REMOVE_CONTROLS. *

* When the visual output is altered by using options of * 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. *

* 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 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_STABLE 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. *

* Some values in the map may be #UBIDI_MAP_NOWHERE if the * corresponding text characters are Bidi marks inserted in the visual output * by the option #UBIDI_OPTION_INSERT_MARKS. *

* When the visual output is altered by using options of * 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_STABLE 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.

* The index map will result in indexMap[logicalIndex]==visualIndex. * @stable ICU 2.0 */ U_STABLE 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.

* The index map will result in indexMap[visualIndex]==logicalIndex. * @stable ICU 2.0 */ U_STABLE 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_STABLE 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 * *

This option does not imply corresponding adjustment of the index * mappings.

* * @see ubidi_setInverse * @see ubidi_writeReordered * @stable ICU 2.0 */ #define UBIDI_INSERT_LRM_FOR_NUMERIC 4 /** * option bit for ubidi_writeReordered(): * remove Bidi control characters * (this does not affect #UBIDI_INSERT_LRM_FOR_NUMERIC) * *

This option does not imply corresponding adjustment of the index * mappings.

* * @see ubidi_writeReordered * @stable ICU 2.0 */ #define UBIDI_REMOVE_BIDI_CONTROLS 8 /** * option bit for ubidi_writeReordered(): * write the output in reverse order * *

This has the same effect as calling 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.

* * @see ubidi_writeReordered * @stable ICU 2.0 */ #define UBIDI_OUTPUT_REVERSE 16 /** * Get the length of the source text processed by the last call to * 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 UBiDi 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_STABLE 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 * ubidi_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_STABLE 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. *

Usually, the function pointer will be propagated to a 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.

* * @param context is a pointer to the callback private data. * * @param c is the code point to get a Bidi class for. * * @return The directional property / Bidi class for the given code point * c if the default class has been overridden, or * #U_BIDI_CLASS_DEFAULT=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. *

If a #UBiDiClassCallback callback is defined and returns a * value other than #U_BIDI_CLASS_DEFAULT=u_getIntPropertyMaxValue(UCHAR_BIDI_CLASS)+1, * that value is used; otherwise the default class determination mechanism is invoked.

* * @param pBiDi is the paragraph 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_STABLE 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. *

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 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_STABLE 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_STABLE 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_STABLE 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_STABLE 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