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intl/icu/source/common/unicode/ubidi.h

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1 /*
2 ******************************************************************************
3 *
4 * Copyright (C) 1999-2013, International Business Machines
5 * Corporation and others. All Rights Reserved.
6 *
7 ******************************************************************************
8 * file name: ubidi.h
9 * encoding: US-ASCII
10 * tab size: 8 (not used)
11 * indentation:4
12 *
13 * created on: 1999jul27
14 * created by: Markus W. Scherer, updated by Matitiahu Allouche
15 */
16
17 #ifndef UBIDI_H
18 #define UBIDI_H
19
20 #include "unicode/utypes.h"
21 #include "unicode/uchar.h"
22 #include "unicode/localpointer.h"
23
24 /**
25 *\file
26 * \brief C API: Bidi algorithm
27 *
28 * <h2>Bidi algorithm for ICU</h2>
29 *
30 * This is an implementation of the Unicode Bidirectional Algorithm.
31 * The algorithm is defined in the
32 * <a href="http://www.unicode.org/unicode/reports/tr9/">Unicode Standard Annex #9</a>.<p>
33 *
34 * Note: Libraries that perform a bidirectional algorithm and
35 * reorder strings accordingly are sometimes called "Storage Layout Engines".
36 * ICU's Bidi and shaping (u_shapeArabic()) APIs can be used at the core of such
37 * "Storage Layout Engines".
38 *
39 * <h3>General remarks about the API:</h3>
40 *
41 * In functions with an error code parameter,
42 * the <code>pErrorCode</code> pointer must be valid
43 * and the value that it points to must not indicate a failure before
44 * the function call. Otherwise, the function returns immediately.
45 * After the function call, the value indicates success or failure.<p>
46 *
47 * The &quot;limit&quot; of a sequence of characters is the position just after their
48 * last character, i.e., one more than that position.<p>
49 *
50 * Some of the API functions provide access to &quot;runs&quot;.
51 * Such a &quot;run&quot; is defined as a sequence of characters
52 * that are at the same embedding level
53 * after performing the Bidi algorithm.<p>
54 *
55 * @author Markus W. Scherer
56 * @version 1.0
57 *
58 *
59 * <h4> Sample code for the ICU Bidi API </h4>
60 *
61 * <h5>Rendering a paragraph with the ICU Bidi API</h5>
62 *
63 * This is (hypothetical) sample code that illustrates
64 * how the ICU Bidi API could be used to render a paragraph of text.
65 * Rendering code depends highly on the graphics system,
66 * therefore this sample code must make a lot of assumptions,
67 * which may or may not match any existing graphics system's properties.
68 *
69 * <p>The basic assumptions are:</p>
70 * <ul>
71 * <li>Rendering is done from left to right on a horizontal line.</li>
72 * <li>A run of single-style, unidirectional text can be rendered at once.</li>
73 * <li>Such a run of text is passed to the graphics system with
74 * characters (code units) in logical order.</li>
75 * <li>The line-breaking algorithm is very complicated
76 * and Locale-dependent -
77 * and therefore its implementation omitted from this sample code.</li>
78 * </ul>
79 *
80 * <pre>
81 * \code
82 *#include "unicode/ubidi.h"
83 *
84 *typedef enum {
85 * styleNormal=0, styleSelected=1,
86 * styleBold=2, styleItalics=4,
87 * styleSuper=8, styleSub=16
88 *} Style;
89 *
90 *typedef struct { int32_t limit; Style style; } StyleRun;
91 *
92 *int getTextWidth(const UChar *text, int32_t start, int32_t limit,
93 * const StyleRun *styleRuns, int styleRunCount);
94 *
95 * // set *pLimit and *pStyleRunLimit for a line
96 * // from text[start] and from styleRuns[styleRunStart]
97 * // using ubidi_getLogicalRun(para, ...)
98 *void getLineBreak(const UChar *text, int32_t start, int32_t *pLimit,
99 * UBiDi *para,
100 * const StyleRun *styleRuns, int styleRunStart, int *pStyleRunLimit,
101 * int *pLineWidth);
102 *
103 * // render runs on a line sequentially, always from left to right
104 *
105 * // prepare rendering a new line
106 * void startLine(UBiDiDirection textDirection, int lineWidth);
107 *
108 * // render a run of text and advance to the right by the run width
109 * // the text[start..limit-1] is always in logical order
110 * void renderRun(const UChar *text, int32_t start, int32_t limit,
111 * UBiDiDirection textDirection, Style style);
112 *
113 * // We could compute a cross-product
114 * // from the style runs with the directional runs
115 * // and then reorder it.
116 * // Instead, here we iterate over each run type
117 * // and render the intersections -
118 * // with shortcuts in simple (and common) cases.
119 * // renderParagraph() is the main function.
120 *
121 * // render a directional run with
122 * // (possibly) multiple style runs intersecting with it
123 * void renderDirectionalRun(const UChar *text,
124 * int32_t start, int32_t limit,
125 * UBiDiDirection direction,
126 * const StyleRun *styleRuns, int styleRunCount) {
127 * int i;
128 *
129 * // iterate over style runs
130 * if(direction==UBIDI_LTR) {
131 * int styleLimit;
132 *
133 * for(i=0; i<styleRunCount; ++i) {
134 * styleLimit=styleRun[i].limit;
135 * if(start<styleLimit) {
136 * if(styleLimit>limit) { styleLimit=limit; }
137 * renderRun(text, start, styleLimit,
138 * direction, styleRun[i].style);
139 * if(styleLimit==limit) { break; }
140 * start=styleLimit;
141 * }
142 * }
143 * } else {
144 * int styleStart;
145 *
146 * for(i=styleRunCount-1; i>=0; --i) {
147 * if(i>0) {
148 * styleStart=styleRun[i-1].limit;
149 * } else {
150 * styleStart=0;
151 * }
152 * if(limit>=styleStart) {
153 * if(styleStart<start) { styleStart=start; }
154 * renderRun(text, styleStart, limit,
155 * direction, styleRun[i].style);
156 * if(styleStart==start) { break; }
157 * limit=styleStart;
158 * }
159 * }
160 * }
161 * }
162 *
163 * // the line object represents text[start..limit-1]
164 * void renderLine(UBiDi *line, const UChar *text,
165 * int32_t start, int32_t limit,
166 * const StyleRun *styleRuns, int styleRunCount) {
167 * UBiDiDirection direction=ubidi_getDirection(line);
168 * if(direction!=UBIDI_MIXED) {
169 * // unidirectional
170 * if(styleRunCount<=1) {
171 * renderRun(text, start, limit, direction, styleRuns[0].style);
172 * } else {
173 * renderDirectionalRun(text, start, limit,
174 * direction, styleRuns, styleRunCount);
175 * }
176 * } else {
177 * // mixed-directional
178 * int32_t count, i, length;
179 * UBiDiLevel level;
180 *
181 * count=ubidi_countRuns(para, pErrorCode);
182 * if(U_SUCCESS(*pErrorCode)) {
183 * if(styleRunCount<=1) {
184 * Style style=styleRuns[0].style;
185 *
186 * // iterate over directional runs
187 * for(i=0; i<count; ++i) {
188 * direction=ubidi_getVisualRun(para, i, &start, &length);
189 * renderRun(text, start, start+length, direction, style);
190 * }
191 * } else {
192 * int32_t j;
193 *
194 * // iterate over both directional and style runs
195 * for(i=0; i<count; ++i) {
196 * direction=ubidi_getVisualRun(line, i, &start, &length);
197 * renderDirectionalRun(text, start, start+length,
198 * direction, styleRuns, styleRunCount);
199 * }
200 * }
201 * }
202 * }
203 * }
204 *
205 *void renderParagraph(const UChar *text, int32_t length,
206 * UBiDiDirection textDirection,
207 * const StyleRun *styleRuns, int styleRunCount,
208 * int lineWidth,
209 * UErrorCode *pErrorCode) {
210 * UBiDi *para;
211 *
212 * if(pErrorCode==NULL || U_FAILURE(*pErrorCode) || length<=0) {
213 * return;
214 * }
215 *
216 * para=ubidi_openSized(length, 0, pErrorCode);
217 * if(para==NULL) { return; }
218 *
219 * ubidi_setPara(para, text, length,
220 * textDirection ? UBIDI_DEFAULT_RTL : UBIDI_DEFAULT_LTR,
221 * NULL, pErrorCode);
222 * if(U_SUCCESS(*pErrorCode)) {
223 * UBiDiLevel paraLevel=1&ubidi_getParaLevel(para);
224 * StyleRun styleRun={ length, styleNormal };
225 * int width;
226 *
227 * if(styleRuns==NULL || styleRunCount<=0) {
228 * styleRunCount=1;
229 * styleRuns=&styleRun;
230 * }
231 *
232 * // assume styleRuns[styleRunCount-1].limit>=length
233 *
234 * width=getTextWidth(text, 0, length, styleRuns, styleRunCount);
235 * if(width<=lineWidth) {
236 * // everything fits onto one line
237 *
238 * // prepare rendering a new line from either left or right
239 * startLine(paraLevel, width);
240 *
241 * renderLine(para, text, 0, length,
242 * styleRuns, styleRunCount);
243 * } else {
244 * UBiDi *line;
245 *
246 * // we need to render several lines
247 * line=ubidi_openSized(length, 0, pErrorCode);
248 * if(line!=NULL) {
249 * int32_t start=0, limit;
250 * int styleRunStart=0, styleRunLimit;
251 *
252 * for(;;) {
253 * limit=length;
254 * styleRunLimit=styleRunCount;
255 * getLineBreak(text, start, &limit, para,
256 * styleRuns, styleRunStart, &styleRunLimit,
257 * &width);
258 * ubidi_setLine(para, start, limit, line, pErrorCode);
259 * if(U_SUCCESS(*pErrorCode)) {
260 * // prepare rendering a new line
261 * // from either left or right
262 * startLine(paraLevel, width);
263 *
264 * renderLine(line, text, start, limit,
265 * styleRuns+styleRunStart,
266 * styleRunLimit-styleRunStart);
267 * }
268 * if(limit==length) { break; }
269 * start=limit;
270 * styleRunStart=styleRunLimit-1;
271 * if(start>=styleRuns[styleRunStart].limit) {
272 * ++styleRunStart;
273 * }
274 * }
275 *
276 * ubidi_close(line);
277 * }
278 * }
279 * }
280 *
281 * ubidi_close(para);
282 *}
283 *\endcode
284 * </pre>
285 */
286
287 /*DOCXX_TAG*/
288 /*@{*/
289
290 /**
291 * UBiDiLevel is the type of the level values in this
292 * Bidi implementation.
293 * It holds an embedding level and indicates the visual direction
294 * by its bit&nbsp;0 (even/odd value).<p>
295 *
296 * It can also hold non-level values for the
297 * <code>paraLevel</code> and <code>embeddingLevels</code>
298 * arguments of <code>ubidi_setPara()</code>; there:
299 * <ul>
300 * <li>bit&nbsp;7 of an <code>embeddingLevels[]</code>
301 * value indicates whether the using application is
302 * specifying the level of a character to <i>override</i> whatever the
303 * Bidi implementation would resolve it to.</li>
304 * <li><code>paraLevel</code> can be set to the
305 * pseudo-level values <code>UBIDI_DEFAULT_LTR</code>
306 * and <code>UBIDI_DEFAULT_RTL</code>.</li>
307 * </ul>
308 *
309 * @see ubidi_setPara
310 *
311 * <p>The related constants are not real, valid level values.
312 * <code>UBIDI_DEFAULT_XXX</code> can be used to specify
313 * a default for the paragraph level for
314 * when the <code>ubidi_setPara()</code> function
315 * shall determine it but there is no
316 * strongly typed character in the input.<p>
317 *
318 * Note that the value for <code>UBIDI_DEFAULT_LTR</code> is even
319 * and the one for <code>UBIDI_DEFAULT_RTL</code> is odd,
320 * just like with normal LTR and RTL level values -
321 * these special values are designed that way. Also, the implementation
322 * assumes that UBIDI_MAX_EXPLICIT_LEVEL is odd.
323 *
324 * @see UBIDI_DEFAULT_LTR
325 * @see UBIDI_DEFAULT_RTL
326 * @see UBIDI_LEVEL_OVERRIDE
327 * @see UBIDI_MAX_EXPLICIT_LEVEL
328 * @stable ICU 2.0
329 */
330 typedef uint8_t UBiDiLevel;
331
332 /** Paragraph level setting.<p>
333 *
334 * Constant indicating that the base direction depends on the first strong
335 * directional character in the text according to the Unicode Bidirectional
336 * Algorithm. If no strong directional character is present,
337 * then set the paragraph level to 0 (left-to-right).<p>
338 *
339 * If this value is used in conjunction with reordering modes
340 * <code>UBIDI_REORDER_INVERSE_LIKE_DIRECT</code> or
341 * <code>UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL</code>, the text to reorder
342 * is assumed to be visual LTR, and the text after reordering is required
343 * to be the corresponding logical string with appropriate contextual
344 * direction. The direction of the result string will be RTL if either
345 * the righmost or leftmost strong character of the source text is RTL
346 * or Arabic Letter, the direction will be LTR otherwise.<p>
347 *
348 * If reordering option <code>UBIDI_OPTION_INSERT_MARKS</code> is set, an RLM may
349 * be added at the beginning of the result string to ensure round trip
350 * (that the result string, when reordered back to visual, will produce
351 * the original source text).
352 * @see UBIDI_REORDER_INVERSE_LIKE_DIRECT
353 * @see UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL
354 * @stable ICU 2.0
355 */
356 #define UBIDI_DEFAULT_LTR 0xfe
357
358 /** Paragraph level setting.<p>
359 *
360 * Constant indicating that the base direction depends on the first strong
361 * directional character in the text according to the Unicode Bidirectional
362 * Algorithm. If no strong directional character is present,
363 * then set the paragraph level to 1 (right-to-left).<p>
364 *
365 * If this value is used in conjunction with reordering modes
366 * <code>UBIDI_REORDER_INVERSE_LIKE_DIRECT</code> or
367 * <code>UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL</code>, the text to reorder
368 * is assumed to be visual LTR, and the text after reordering is required
369 * to be the corresponding logical string with appropriate contextual
370 * direction. The direction of the result string will be RTL if either
371 * the righmost or leftmost strong character of the source text is RTL
372 * or Arabic Letter, or if the text contains no strong character;
373 * the direction will be LTR otherwise.<p>
374 *
375 * If reordering option <code>UBIDI_OPTION_INSERT_MARKS</code> is set, an RLM may
376 * be added at the beginning of the result string to ensure round trip
377 * (that the result string, when reordered back to visual, will produce
378 * the original source text).
379 * @see UBIDI_REORDER_INVERSE_LIKE_DIRECT
380 * @see UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL
381 * @stable ICU 2.0
382 */
383 #define UBIDI_DEFAULT_RTL 0xff
384
385 /**
386 * Maximum explicit embedding level.
387 * (The maximum resolved level can be up to <code>UBIDI_MAX_EXPLICIT_LEVEL+1</code>).
388 * @stable ICU 2.0
389 */
390 #define UBIDI_MAX_EXPLICIT_LEVEL 125
391
392 /** Bit flag for level input.
393 * Overrides directional properties.
394 * @stable ICU 2.0
395 */
396 #define UBIDI_LEVEL_OVERRIDE 0x80
397
398 /**
399 * Special value which can be returned by the mapping functions when a logical
400 * index has no corresponding visual index or vice-versa. This may happen
401 * for the logical-to-visual mapping of a Bidi control when option
402 * <code>#UBIDI_OPTION_REMOVE_CONTROLS</code> is specified. This can also happen
403 * for the visual-to-logical mapping of a Bidi mark (LRM or RLM) inserted
404 * by option <code>#UBIDI_OPTION_INSERT_MARKS</code>.
405 * @see ubidi_getVisualIndex
406 * @see ubidi_getVisualMap
407 * @see ubidi_getLogicalIndex
408 * @see ubidi_getLogicalMap
409 * @stable ICU 3.6
410 */
411 #define UBIDI_MAP_NOWHERE (-1)
412
413 /**
414 * <code>UBiDiDirection</code> values indicate the text direction.
415 * @stable ICU 2.0
416 */
417 enum UBiDiDirection {
418 /** Left-to-right text. This is a 0 value.
419 * <ul>
420 * <li>As return value for <code>ubidi_getDirection()</code>, it means
421 * that the source string contains no right-to-left characters, or
422 * that the source string is empty and the paragraph level is even.
423 * <li> As return value for <code>ubidi_getBaseDirection()</code>, it
424 * means that the first strong character of the source string has
425 * a left-to-right direction.
426 * </ul>
427 * @stable ICU 2.0
428 */
429 UBIDI_LTR,
430 /** Right-to-left text. This is a 1 value.
431 * <ul>
432 * <li>As return value for <code>ubidi_getDirection()</code>, it means
433 * that the source string contains no left-to-right characters, or
434 * that the source string is empty and the paragraph level is odd.
435 * <li> As return value for <code>ubidi_getBaseDirection()</code>, it
436 * means that the first strong character of the source string has
437 * a right-to-left direction.
438 * </ul>
439 * @stable ICU 2.0
440 */
441 UBIDI_RTL,
442 /** Mixed-directional text.
443 * <p>As return value for <code>ubidi_getDirection()</code>, it means
444 * that the source string contains both left-to-right and
445 * right-to-left characters.
446 * @stable ICU 2.0
447 */
448 UBIDI_MIXED,
449 /** No strongly directional text.
450 * <p>As return value for <code>ubidi_getBaseDirection()</code>, it means
451 * that the source string is missing or empty, or contains neither left-to-right
452 * nor right-to-left characters.
453 * @stable ICU 4.6
454 */
455 UBIDI_NEUTRAL
456 };
457
458 /** @stable ICU 2.0 */
459 typedef enum UBiDiDirection UBiDiDirection;
460
461 /**
462 * Forward declaration of the <code>UBiDi</code> structure for the declaration of
463 * the API functions. Its fields are implementation-specific.<p>
464 * This structure holds information about a paragraph (or multiple paragraphs)
465 * of text with Bidi-algorithm-related details, or about one line of
466 * such a paragraph.<p>
467 * Reordering can be done on a line, or on one or more paragraphs which are
468 * then interpreted each as one single line.
469 * @stable ICU 2.0
470 */
471 struct UBiDi;
472
473 /** @stable ICU 2.0 */
474 typedef struct UBiDi UBiDi;
475
476 /**
477 * Allocate a <code>UBiDi</code> structure.
478 * Such an object is initially empty. It is assigned
479 * the Bidi properties of a piece of text containing one or more paragraphs
480 * by <code>ubidi_setPara()</code>
481 * or the Bidi properties of a line within a paragraph by
482 * <code>ubidi_setLine()</code>.<p>
483 * This object can be reused for as long as it is not deallocated
484 * by calling <code>ubidi_close()</code>.<p>
485 * <code>ubidi_setPara()</code> and <code>ubidi_setLine()</code> will allocate
486 * additional memory for internal structures as necessary.
487 *
488 * @return An empty <code>UBiDi</code> object.
489 * @stable ICU 2.0
490 */
491 U_STABLE UBiDi * U_EXPORT2
492 ubidi_open(void);
493
494 /**
495 * Allocate a <code>UBiDi</code> structure with preallocated memory
496 * for internal structures.
497 * This function provides a <code>UBiDi</code> object like <code>ubidi_open()</code>
498 * with no arguments, but it also preallocates memory for internal structures
499 * according to the sizings supplied by the caller.<p>
500 * Subsequent functions will not allocate any more memory, and are thus
501 * guaranteed not to fail because of lack of memory.<p>
502 * The preallocation can be limited to some of the internal memory
503 * by setting some values to 0 here. That means that if, e.g.,
504 * <code>maxRunCount</code> cannot be reasonably predetermined and should not
505 * be set to <code>maxLength</code> (the only failproof value) to avoid
506 * wasting memory, then <code>maxRunCount</code> could be set to 0 here
507 * and the internal structures that are associated with it will be allocated
508 * on demand, just like with <code>ubidi_open()</code>.
509 *
510 * @param maxLength is the maximum text or line length that internal memory
511 * will be preallocated for. An attempt to associate this object with a
512 * longer text will fail, unless this value is 0, which leaves the allocation
513 * up to the implementation.
514 *
515 * @param maxRunCount is the maximum anticipated number of same-level runs
516 * that internal memory will be preallocated for. An attempt to access
517 * visual runs on an object that was not preallocated for as many runs
518 * as the text was actually resolved to will fail,
519 * unless this value is 0, which leaves the allocation up to the implementation.<br><br>
520 * The number of runs depends on the actual text and maybe anywhere between
521 * 1 and <code>maxLength</code>. It is typically small.
522 *
523 * @param pErrorCode must be a valid pointer to an error code value.
524 *
525 * @return An empty <code>UBiDi</code> object with preallocated memory.
526 * @stable ICU 2.0
527 */
528 U_STABLE UBiDi * U_EXPORT2
529 ubidi_openSized(int32_t maxLength, int32_t maxRunCount, UErrorCode *pErrorCode);
530
531 /**
532 * <code>ubidi_close()</code> must be called to free the memory
533 * associated with a UBiDi object.<p>
534 *
535 * <strong>Important: </strong>
536 * A parent <code>UBiDi</code> object must not be destroyed or reused if
537 * it still has children.
538 * If a <code>UBiDi</code> object has become the <i>child</i>
539 * of another one (its <i>parent</i>) by calling
540 * <code>ubidi_setLine()</code>, then the child object must
541 * be destroyed (closed) or reused (by calling
542 * <code>ubidi_setPara()</code> or <code>ubidi_setLine()</code>)
543 * before the parent object.
544 *
545 * @param pBiDi is a <code>UBiDi</code> object.
546 *
547 * @see ubidi_setPara
548 * @see ubidi_setLine
549 * @stable ICU 2.0
550 */
551 U_STABLE void U_EXPORT2
552 ubidi_close(UBiDi *pBiDi);
553
554 #if U_SHOW_CPLUSPLUS_API
555
556 U_NAMESPACE_BEGIN
557
558 /**
559 * \class LocalUBiDiPointer
560 * "Smart pointer" class, closes a UBiDi via ubidi_close().
561 * For most methods see the LocalPointerBase base class.
562 *
563 * @see LocalPointerBase
564 * @see LocalPointer
565 * @stable ICU 4.4
566 */
567 U_DEFINE_LOCAL_OPEN_POINTER(LocalUBiDiPointer, UBiDi, ubidi_close);
568
569 U_NAMESPACE_END
570
571 #endif
572
573 /**
574 * Modify the operation of the Bidi algorithm such that it
575 * approximates an "inverse Bidi" algorithm. This function
576 * must be called before <code>ubidi_setPara()</code>.
577 *
578 * <p>The normal operation of the Bidi algorithm as described
579 * in the Unicode Technical Report is to take text stored in logical
580 * (keyboard, typing) order and to determine the reordering of it for visual
581 * rendering.
582 * Some legacy systems store text in visual order, and for operations
583 * with standard, Unicode-based algorithms, the text needs to be transformed
584 * to logical order. This is effectively the inverse algorithm of the
585 * described Bidi algorithm. Note that there is no standard algorithm for
586 * this "inverse Bidi" and that the current implementation provides only an
587 * approximation of "inverse Bidi".</p>
588 *
589 * <p>With <code>isInverse</code> set to <code>TRUE</code>,
590 * this function changes the behavior of some of the subsequent functions
591 * in a way that they can be used for the inverse Bidi algorithm.
592 * Specifically, runs of text with numeric characters will be treated in a
593 * special way and may need to be surrounded with LRM characters when they are
594 * written in reordered sequence.</p>
595 *
596 * <p>Output runs should be retrieved using <code>ubidi_getVisualRun()</code>.
597 * Since the actual input for "inverse Bidi" is visually ordered text and
598 * <code>ubidi_getVisualRun()</code> gets the reordered runs, these are actually
599 * the runs of the logically ordered output.</p>
600 *
601 * <p>Calling this function with argument <code>isInverse</code> set to
602 * <code>TRUE</code> is equivalent to calling
603 * <code>ubidi_setReorderingMode</code> with argument
604 * <code>reorderingMode</code>
605 * set to <code>#UBIDI_REORDER_INVERSE_NUMBERS_AS_L</code>.<br>
606 * Calling this function with argument <code>isInverse</code> set to
607 * <code>FALSE</code> is equivalent to calling
608 * <code>ubidi_setReorderingMode</code> with argument
609 * <code>reorderingMode</code>
610 * set to <code>#UBIDI_REORDER_DEFAULT</code>.
611 *
612 * @param pBiDi is a <code>UBiDi</code> object.
613 *
614 * @param isInverse specifies "forward" or "inverse" Bidi operation.
615 *
616 * @see ubidi_setPara
617 * @see ubidi_writeReordered
618 * @see ubidi_setReorderingMode
619 * @stable ICU 2.0
620 */
621 U_STABLE void U_EXPORT2
622 ubidi_setInverse(UBiDi *pBiDi, UBool isInverse);
623
624 /**
625 * Is this Bidi object set to perform the inverse Bidi algorithm?
626 * <p>Note: calling this function after setting the reordering mode with
627 * <code>ubidi_setReorderingMode</code> will return <code>TRUE</code> if the
628 * reordering mode was set to <code>#UBIDI_REORDER_INVERSE_NUMBERS_AS_L</code>,
629 * <code>FALSE</code> for all other values.</p>
630 *
631 * @param pBiDi is a <code>UBiDi</code> object.
632 * @return TRUE if the Bidi object is set to perform the inverse Bidi algorithm
633 * by handling numbers as L.
634 *
635 * @see ubidi_setInverse
636 * @see ubidi_setReorderingMode
637 * @stable ICU 2.0
638 */
639
640 U_STABLE UBool U_EXPORT2
641 ubidi_isInverse(UBiDi *pBiDi);
642
643 /**
644 * Specify whether block separators must be allocated level zero,
645 * so that successive paragraphs will progress from left to right.
646 * This function must be called before <code>ubidi_setPara()</code>.
647 * Paragraph separators (B) may appear in the text. Setting them to level zero
648 * means that all paragraph separators (including one possibly appearing
649 * in the last text position) are kept in the reordered text after the text
650 * that they follow in the source text.
651 * When this feature is not enabled, a paragraph separator at the last
652 * position of the text before reordering will go to the first position
653 * of the reordered text when the paragraph level is odd.
654 *
655 * @param pBiDi is a <code>UBiDi</code> object.
656 *
657 * @param orderParagraphsLTR specifies whether paragraph separators (B) must
658 * receive level 0, so that successive paragraphs progress from left to right.
659 *
660 * @see ubidi_setPara
661 * @stable ICU 3.4
662 */
663 U_STABLE void U_EXPORT2
664 ubidi_orderParagraphsLTR(UBiDi *pBiDi, UBool orderParagraphsLTR);
665
666 /**
667 * Is this Bidi object set to allocate level 0 to block separators so that
668 * successive paragraphs progress from left to right?
669 *
670 * @param pBiDi is a <code>UBiDi</code> object.
671 * @return TRUE if the Bidi object is set to allocate level 0 to block
672 * separators.
673 *
674 * @see ubidi_orderParagraphsLTR
675 * @stable ICU 3.4
676 */
677 U_STABLE UBool U_EXPORT2
678 ubidi_isOrderParagraphsLTR(UBiDi *pBiDi);
679
680 /**
681 * <code>UBiDiReorderingMode</code> values indicate which variant of the Bidi
682 * algorithm to use.
683 *
684 * @see ubidi_setReorderingMode
685 * @stable ICU 3.6
686 */
687 typedef enum UBiDiReorderingMode {
688 /** Regular Logical to Visual Bidi algorithm according to Unicode.
689 * This is a 0 value.
690 * @stable ICU 3.6 */
691 UBIDI_REORDER_DEFAULT = 0,
692 /** Logical to Visual algorithm which handles numbers in a way which
693 * mimicks the behavior of Windows XP.
694 * @stable ICU 3.6 */
695 UBIDI_REORDER_NUMBERS_SPECIAL,
696 /** Logical to Visual algorithm grouping numbers with adjacent R characters
697 * (reversible algorithm).
698 * @stable ICU 3.6 */
699 UBIDI_REORDER_GROUP_NUMBERS_WITH_R,
700 /** Reorder runs only to transform a Logical LTR string to the Logical RTL
701 * string with the same display, or vice-versa.<br>
702 * If this mode is set together with option
703 * <code>#UBIDI_OPTION_INSERT_MARKS</code>, some Bidi controls in the source
704 * text may be removed and other controls may be added to produce the
705 * minimum combination which has the required display.
706 * @stable ICU 3.6 */
707 UBIDI_REORDER_RUNS_ONLY,
708 /** Visual to Logical algorithm which handles numbers like L
709 * (same algorithm as selected by <code>ubidi_setInverse(TRUE)</code>.
710 * @see ubidi_setInverse
711 * @stable ICU 3.6 */
712 UBIDI_REORDER_INVERSE_NUMBERS_AS_L,
713 /** Visual to Logical algorithm equivalent to the regular Logical to Visual
714 * algorithm.
715 * @stable ICU 3.6 */
716 UBIDI_REORDER_INVERSE_LIKE_DIRECT,
717 /** Inverse Bidi (Visual to Logical) algorithm for the
718 * <code>UBIDI_REORDER_NUMBERS_SPECIAL</code> Bidi algorithm.
719 * @stable ICU 3.6 */
720 UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL,
721 /** Number of values for reordering mode.
722 * @stable ICU 3.6 */
723 UBIDI_REORDER_COUNT
724 } UBiDiReorderingMode;
725
726 /**
727 * Modify the operation of the Bidi algorithm such that it implements some
728 * variant to the basic Bidi algorithm or approximates an "inverse Bidi"
729 * algorithm, depending on different values of the "reordering mode".
730 * This function must be called before <code>ubidi_setPara()</code>, and stays
731 * in effect until called again with a different argument.
732 *
733 * <p>The normal operation of the Bidi algorithm as described
734 * in the Unicode Standard Annex #9 is to take text stored in logical
735 * (keyboard, typing) order and to determine how to reorder it for visual
736 * rendering.</p>
737 *
738 * <p>With the reordering mode set to a value other than
739 * <code>#UBIDI_REORDER_DEFAULT</code>, this function changes the behavior of
740 * some of the subsequent functions in a way such that they implement an
741 * inverse Bidi algorithm or some other algorithm variants.</p>
742 *
743 * <p>Some legacy systems store text in visual order, and for operations
744 * with standard, Unicode-based algorithms, the text needs to be transformed
745 * into logical order. This is effectively the inverse algorithm of the
746 * described Bidi algorithm. Note that there is no standard algorithm for
747 * this "inverse Bidi", so a number of variants are implemented here.</p>
748 *
749 * <p>In other cases, it may be desirable to emulate some variant of the
750 * Logical to Visual algorithm (e.g. one used in MS Windows), or perform a
751 * Logical to Logical transformation.</p>
752 *
753 * <ul>
754 * <li>When the reordering mode is set to <code>#UBIDI_REORDER_DEFAULT</code>,
755 * the standard Bidi Logical to Visual algorithm is applied.</li>
756 *
757 * <li>When the reordering mode is set to
758 * <code>#UBIDI_REORDER_NUMBERS_SPECIAL</code>,
759 * the algorithm used to perform Bidi transformations when calling
760 * <code>ubidi_setPara</code> should approximate the algorithm used in
761 * Microsoft Windows XP rather than strictly conform to the Unicode Bidi
762 * algorithm.
763 * <br>
764 * The differences between the basic algorithm and the algorithm addressed
765 * by this option are as follows:
766 * <ul>
767 * <li>Within text at an even embedding level, the sequence "123AB"
768 * (where AB represent R or AL letters) is transformed to "123BA" by the
769 * Unicode algorithm and to "BA123" by the Windows algorithm.</li>
770 * <li>Arabic-Indic numbers (AN) are handled by the Windows algorithm just
771 * like regular numbers (EN).</li>
772 * </ul></li>
773 *
774 * <li>When the reordering mode is set to
775 * <code>#UBIDI_REORDER_GROUP_NUMBERS_WITH_R</code>,
776 * numbers located between LTR text and RTL text are associated with the RTL
777 * text. For instance, an LTR paragraph with content "abc 123 DEF" (where
778 * upper case letters represent RTL characters) will be transformed to
779 * "abc FED 123" (and not "abc 123 FED"), "DEF 123 abc" will be transformed
780 * to "123 FED abc" and "123 FED abc" will be transformed to "DEF 123 abc".
781 * This makes the algorithm reversible and makes it useful when round trip
782 * (from visual to logical and back to visual) must be achieved without
783 * adding LRM characters. However, this is a variation from the standard
784 * Unicode Bidi algorithm.<br>
785 * The source text should not contain Bidi control characters other than LRM
786 * or RLM.</li>
787 *
788 * <li>When the reordering mode is set to
789 * <code>#UBIDI_REORDER_RUNS_ONLY</code>,
790 * a "Logical to Logical" transformation must be performed:
791 * <ul>
792 * <li>If the default text level of the source text (argument <code>paraLevel</code>
793 * in <code>ubidi_setPara</code>) is even, the source text will be handled as
794 * LTR logical text and will be transformed to the RTL logical text which has
795 * the same LTR visual display.</li>
796 * <li>If the default level of the source text is odd, the source text
797 * will be handled as RTL logical text and will be transformed to the
798 * LTR logical text which has the same LTR visual display.</li>
799 * </ul>
800 * This mode may be needed when logical text which is basically Arabic or
801 * Hebrew, with possible included numbers or phrases in English, has to be
802 * displayed as if it had an even embedding level (this can happen if the
803 * displaying application treats all text as if it was basically LTR).
804 * <br>
805 * This mode may also be needed in the reverse case, when logical text which is
806 * basically English, with possible included phrases in Arabic or Hebrew, has to
807 * be displayed as if it had an odd embedding level.
808 * <br>
809 * Both cases could be handled by adding LRE or RLE at the head of the text,
810 * if the display subsystem supports these formatting controls. If it does not,
811 * the problem may be handled by transforming the source text in this mode
812 * before displaying it, so that it will be displayed properly.<br>
813 * The source text should not contain Bidi control characters other than LRM
814 * or RLM.</li>
815 *
816 * <li>When the reordering mode is set to
817 * <code>#UBIDI_REORDER_INVERSE_NUMBERS_AS_L</code>, an "inverse Bidi" algorithm
818 * is applied.
819 * Runs of text with numeric characters will be treated like LTR letters and
820 * may need to be surrounded with LRM characters when they are written in
821 * reordered sequence (the option <code>#UBIDI_INSERT_LRM_FOR_NUMERIC</code> can
822 * be used with function <code>ubidi_writeReordered</code> to this end. This
823 * mode is equivalent to calling <code>ubidi_setInverse()</code> with
824 * argument <code>isInverse</code> set to <code>TRUE</code>.</li>
825 *
826 * <li>When the reordering mode is set to
827 * <code>#UBIDI_REORDER_INVERSE_LIKE_DIRECT</code>, the "direct" Logical to Visual
828 * Bidi algorithm is used as an approximation of an "inverse Bidi" algorithm.
829 * This mode is similar to mode <code>#UBIDI_REORDER_INVERSE_NUMBERS_AS_L</code>
830 * but is closer to the regular Bidi algorithm.
831 * <br>
832 * For example, an LTR paragraph with the content "FED 123 456 CBA" (where
833 * upper case represents RTL characters) will be transformed to
834 * "ABC 456 123 DEF", as opposed to "DEF 123 456 ABC"
835 * with mode <code>UBIDI_REORDER_INVERSE_NUMBERS_AS_L</code>.<br>
836 * When used in conjunction with option
837 * <code>#UBIDI_OPTION_INSERT_MARKS</code>, this mode generally
838 * adds Bidi marks to the output significantly more sparingly than mode
839 * <code>#UBIDI_REORDER_INVERSE_NUMBERS_AS_L</code> with option
840 * <code>#UBIDI_INSERT_LRM_FOR_NUMERIC</code> in calls to
841 * <code>ubidi_writeReordered</code>.</li>
842 *
843 * <li>When the reordering mode is set to
844 * <code>#UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL</code>, the Logical to Visual
845 * Bidi algorithm used in Windows XP is used as an approximation of an "inverse Bidi" algorithm.
846 * <br>
847 * For example, an LTR paragraph with the content "abc FED123" (where
848 * upper case represents RTL characters) will be transformed to "abc 123DEF."</li>
849 * </ul>
850 *
851 * <p>In all the reordering modes specifying an "inverse Bidi" algorithm
852 * (i.e. those with a name starting with <code>UBIDI_REORDER_INVERSE</code>),
853 * output runs should be retrieved using
854 * <code>ubidi_getVisualRun()</code>, and the output text with
855 * <code>ubidi_writeReordered()</code>. The caller should keep in mind that in
856 * "inverse Bidi" modes the input is actually visually ordered text and
857 * reordered output returned by <code>ubidi_getVisualRun()</code> or
858 * <code>ubidi_writeReordered()</code> are actually runs or character string
859 * of logically ordered output.<br>
860 * For all the "inverse Bidi" modes, the source text should not contain
861 * Bidi control characters other than LRM or RLM.</p>
862 *
863 * <p>Note that option <code>#UBIDI_OUTPUT_REVERSE</code> of
864 * <code>ubidi_writeReordered</code> has no useful meaning and should not be
865 * used in conjunction with any value of the reordering mode specifying
866 * "inverse Bidi" or with value <code>UBIDI_REORDER_RUNS_ONLY</code>.
867 *
868 * @param pBiDi is a <code>UBiDi</code> object.
869 * @param reorderingMode specifies the required variant of the Bidi algorithm.
870 *
871 * @see UBiDiReorderingMode
872 * @see ubidi_setInverse
873 * @see ubidi_setPara
874 * @see ubidi_writeReordered
875 * @stable ICU 3.6
876 */
877 U_STABLE void U_EXPORT2
878 ubidi_setReorderingMode(UBiDi *pBiDi, UBiDiReorderingMode reorderingMode);
879
880 /**
881 * What is the requested reordering mode for a given Bidi object?
882 *
883 * @param pBiDi is a <code>UBiDi</code> object.
884 * @return the current reordering mode of the Bidi object
885 * @see ubidi_setReorderingMode
886 * @stable ICU 3.6
887 */
888 U_STABLE UBiDiReorderingMode U_EXPORT2
889 ubidi_getReorderingMode(UBiDi *pBiDi);
890
891 /**
892 * <code>UBiDiReorderingOption</code> values indicate which options are
893 * specified to affect the Bidi algorithm.
894 *
895 * @see ubidi_setReorderingOptions
896 * @stable ICU 3.6
897 */
898 typedef enum UBiDiReorderingOption {
899 /**
900 * option value for <code>ubidi_setReorderingOptions</code>:
901 * disable all the options which can be set with this function
902 * @see ubidi_setReorderingOptions
903 * @stable ICU 3.6
904 */
905 UBIDI_OPTION_DEFAULT = 0,
906
907 /**
908 * option bit for <code>ubidi_setReorderingOptions</code>:
909 * insert Bidi marks (LRM or RLM) when needed to ensure correct result of
910 * a reordering to a Logical order
911 *
912 * <p>This option must be set or reset before calling
913 * <code>ubidi_setPara</code>.</p>
914 *
915 * <p>This option is significant only with reordering modes which generate
916 * a result with Logical order, specifically:</p>
917 * <ul>
918 * <li><code>#UBIDI_REORDER_RUNS_ONLY</code></li>
919 * <li><code>#UBIDI_REORDER_INVERSE_NUMBERS_AS_L</code></li>
920 * <li><code>#UBIDI_REORDER_INVERSE_LIKE_DIRECT</code></li>
921 * <li><code>#UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL</code></li>
922 * </ul>
923 *
924 * <p>If this option is set in conjunction with reordering mode
925 * <code>#UBIDI_REORDER_INVERSE_NUMBERS_AS_L</code> or with calling
926 * <code>ubidi_setInverse(TRUE)</code>, it implies
927 * option <code>#UBIDI_INSERT_LRM_FOR_NUMERIC</code>
928 * in calls to function <code>ubidi_writeReordered()</code>.</p>
929 *
930 * <p>For other reordering modes, a minimum number of LRM or RLM characters
931 * will be added to the source text after reordering it so as to ensure
932 * round trip, i.e. when applying the inverse reordering mode on the
933 * resulting logical text with removal of Bidi marks
934 * (option <code>#UBIDI_OPTION_REMOVE_CONTROLS</code> set before calling
935 * <code>ubidi_setPara()</code> or option <code>#UBIDI_REMOVE_BIDI_CONTROLS</code>
936 * in <code>ubidi_writeReordered</code>), the result will be identical to the
937 * source text in the first transformation.
938 *
939 * <p>This option will be ignored if specified together with option
940 * <code>#UBIDI_OPTION_REMOVE_CONTROLS</code>. It inhibits option
941 * <code>UBIDI_REMOVE_BIDI_CONTROLS</code> in calls to function
942 * <code>ubidi_writeReordered()</code> and it implies option
943 * <code>#UBIDI_INSERT_LRM_FOR_NUMERIC</code> in calls to function
944 * <code>ubidi_writeReordered()</code> if the reordering mode is
945 * <code>#UBIDI_REORDER_INVERSE_NUMBERS_AS_L</code>.</p>
946 *
947 * @see ubidi_setReorderingMode
948 * @see ubidi_setReorderingOptions
949 * @stable ICU 3.6
950 */
951 UBIDI_OPTION_INSERT_MARKS = 1,
952
953 /**
954 * option bit for <code>ubidi_setReorderingOptions</code>:
955 * remove Bidi control characters
956 *
957 * <p>This option must be set or reset before calling
958 * <code>ubidi_setPara</code>.</p>
959 *
960 * <p>This option nullifies option <code>#UBIDI_OPTION_INSERT_MARKS</code>.
961 * It inhibits option <code>#UBIDI_INSERT_LRM_FOR_NUMERIC</code> in calls
962 * to function <code>ubidi_writeReordered()</code> and it implies option
963 * <code>#UBIDI_REMOVE_BIDI_CONTROLS</code> in calls to that function.</p>
964 *
965 * @see ubidi_setReorderingMode
966 * @see ubidi_setReorderingOptions
967 * @stable ICU 3.6
968 */
969 UBIDI_OPTION_REMOVE_CONTROLS = 2,
970
971 /**
972 * option bit for <code>ubidi_setReorderingOptions</code>:
973 * process the output as part of a stream to be continued
974 *
975 * <p>This option must be set or reset before calling
976 * <code>ubidi_setPara</code>.</p>
977 *
978 * <p>This option specifies that the caller is interested in processing large
979 * text object in parts.
980 * The results of the successive calls are expected to be concatenated by the
981 * caller. Only the call for the last part will have this option bit off.</p>
982 *
983 * <p>When this option bit is on, <code>ubidi_setPara()</code> may process
984 * less than the full source text in order to truncate the text at a meaningful
985 * boundary. The caller should call <code>ubidi_getProcessedLength()</code>
986 * immediately after calling <code>ubidi_setPara()</code> in order to
987 * determine how much of the source text has been processed.
988 * Source text beyond that length should be resubmitted in following calls to
989 * <code>ubidi_setPara</code>. The processed length may be less than
990 * the length of the source text if a character preceding the last character of
991 * the source text constitutes a reasonable boundary (like a block separator)
992 * for text to be continued.<br>
993 * If the last character of the source text constitutes a reasonable
994 * boundary, the whole text will be processed at once.<br>
995 * If nowhere in the source text there exists
996 * such a reasonable boundary, the processed length will be zero.<br>
997 * The caller should check for such an occurrence and do one of the following:
998 * <ul><li>submit a larger amount of text with a better chance to include
999 * a reasonable boundary.</li>
1000 * <li>resubmit the same text after turning off option
1001 * <code>UBIDI_OPTION_STREAMING</code>.</li></ul>
1002 * In all cases, this option should be turned off before processing the last
1003 * part of the text.</p>
1004 *
1005 * <p>When the <code>UBIDI_OPTION_STREAMING</code> option is used,
1006 * it is recommended to call <code>ubidi_orderParagraphsLTR()</code> with
1007 * argument <code>orderParagraphsLTR</code> set to <code>TRUE</code> before
1008 * calling <code>ubidi_setPara</code> so that later paragraphs may be
1009 * concatenated to previous paragraphs on the right.</p>
1010 *
1011 * @see ubidi_setReorderingMode
1012 * @see ubidi_setReorderingOptions
1013 * @see ubidi_getProcessedLength
1014 * @see ubidi_orderParagraphsLTR
1015 * @stable ICU 3.6
1016 */
1017 UBIDI_OPTION_STREAMING = 4
1018 } UBiDiReorderingOption;
1019
1020 /**
1021 * Specify which of the reordering options
1022 * should be applied during Bidi transformations.
1023 *
1024 * @param pBiDi is a <code>UBiDi</code> object.
1025 * @param reorderingOptions is a combination of zero or more of the following
1026 * options:
1027 * <code>#UBIDI_OPTION_DEFAULT</code>, <code>#UBIDI_OPTION_INSERT_MARKS</code>,
1028 * <code>#UBIDI_OPTION_REMOVE_CONTROLS</code>, <code>#UBIDI_OPTION_STREAMING</code>.
1029 *
1030 * @see ubidi_getReorderingOptions
1031 * @stable ICU 3.6
1032 */
1033 U_STABLE void U_EXPORT2
1034 ubidi_setReorderingOptions(UBiDi *pBiDi, uint32_t reorderingOptions);
1035
1036 /**
1037 * What are the reordering options applied to a given Bidi object?
1038 *
1039 * @param pBiDi is a <code>UBiDi</code> object.
1040 * @return the current reordering options of the Bidi object
1041 * @see ubidi_setReorderingOptions
1042 * @stable ICU 3.6
1043 */
1044 U_STABLE uint32_t U_EXPORT2
1045 ubidi_getReorderingOptions(UBiDi *pBiDi);
1046
1047 /**
1048 * Set the context before a call to ubidi_setPara().<p>
1049 *
1050 * ubidi_setPara() computes the left-right directionality for a given piece
1051 * of text which is supplied as one of its arguments. Sometimes this piece
1052 * of text (the "main text") should be considered in context, because text
1053 * appearing before ("prologue") and/or after ("epilogue") the main text
1054 * may affect the result of this computation.<p>
1055 *
1056 * This function specifies the prologue and/or the epilogue for the next
1057 * call to ubidi_setPara(). The characters specified as prologue and
1058 * epilogue should not be modified by the calling program until the call
1059 * to ubidi_setPara() has returned. If successive calls to ubidi_setPara()
1060 * all need specification of a context, ubidi_setContext() must be called
1061 * before each call to ubidi_setPara(). In other words, a context is not
1062 * "remembered" after the following successful call to ubidi_setPara().<p>
1063 *
1064 * If a call to ubidi_setPara() specifies UBIDI_DEFAULT_LTR or
1065 * UBIDI_DEFAULT_RTL as paraLevel and is preceded by a call to
1066 * ubidi_setContext() which specifies a prologue, the paragraph level will
1067 * be computed taking in consideration the text in the prologue.<p>
1068 *
1069 * When ubidi_setPara() is called without a previous call to
1070 * ubidi_setContext, the main text is handled as if preceded and followed
1071 * by strong directional characters at the current paragraph level.
1072 * Calling ubidi_setContext() with specification of a prologue will change
1073 * this behavior by handling the main text as if preceded by the last
1074 * strong character appearing in the prologue, if any.
1075 * Calling ubidi_setContext() with specification of an epilogue will change
1076 * the behavior of ubidi_setPara() by handling the main text as if followed
1077 * by the first strong character or digit appearing in the epilogue, if any.<p>
1078 *
1079 * Note 1: if <code>ubidi_setContext</code> is called repeatedly without
1080 * calling <code>ubidi_setPara</code>, the earlier calls have no effect,
1081 * only the last call will be remembered for the next call to
1082 * <code>ubidi_setPara</code>.<p>
1083 *
1084 * Note 2: calling <code>ubidi_setContext(pBiDi, NULL, 0, NULL, 0, &errorCode)</code>
1085 * cancels any previous setting of non-empty prologue or epilogue.
1086 * The next call to <code>ubidi_setPara()</code> will process no
1087 * prologue or epilogue.<p>
1088 *
1089 * Note 3: users must be aware that even after setting the context
1090 * before a call to ubidi_setPara() to perform e.g. a logical to visual
1091 * transformation, the resulting string may not be identical to what it
1092 * would have been if all the text, including prologue and epilogue, had
1093 * been processed together.<br>
1094 * Example (upper case letters represent RTL characters):<br>
1095 * &nbsp;&nbsp;prologue = "<code>abc DE</code>"<br>
1096 * &nbsp;&nbsp;epilogue = none<br>
1097 * &nbsp;&nbsp;main text = "<code>FGH xyz</code>"<br>
1098 * &nbsp;&nbsp;paraLevel = UBIDI_LTR<br>
1099 * &nbsp;&nbsp;display without prologue = "<code>HGF xyz</code>"
1100 * ("HGF" is adjacent to "xyz")<br>
1101 * &nbsp;&nbsp;display with prologue = "<code>abc HGFED xyz</code>"
1102 * ("HGF" is not adjacent to "xyz")<br>
1103 *
1104 * @param pBiDi is a paragraph <code>UBiDi</code> object.
1105 *
1106 * @param prologue is a pointer to the text which precedes the text that
1107 * will be specified in a coming call to ubidi_setPara().
1108 * If there is no prologue to consider, then <code>proLength</code>
1109 * must be zero and this pointer can be NULL.
1110 *
1111 * @param proLength is the length of the prologue; if <code>proLength==-1</code>
1112 * then the prologue must be zero-terminated.
1113 * Otherwise proLength must be >= 0. If <code>proLength==0</code>, it means
1114 * that there is no prologue to consider.
1115 *
1116 * @param epilogue is a pointer to the text which follows the text that
1117 * will be specified in a coming call to ubidi_setPara().
1118 * If there is no epilogue to consider, then <code>epiLength</code>
1119 * must be zero and this pointer can be NULL.
1120 *
1121 * @param epiLength is the length of the epilogue; if <code>epiLength==-1</code>
1122 * then the epilogue must be zero-terminated.
1123 * Otherwise epiLength must be >= 0. If <code>epiLength==0</code>, it means
1124 * that there is no epilogue to consider.
1125 *
1126 * @param pErrorCode must be a valid pointer to an error code value.
1127 *
1128 * @see ubidi_setPara
1129 * @stable ICU 4.8
1130 */
1131 U_STABLE void U_EXPORT2
1132 ubidi_setContext(UBiDi *pBiDi,
1133 const UChar *prologue, int32_t proLength,
1134 const UChar *epilogue, int32_t epiLength,
1135 UErrorCode *pErrorCode);
1136
1137 /**
1138 * Perform the Unicode Bidi algorithm. It is defined in the
1139 * <a href="http://www.unicode.org/unicode/reports/tr9/">Unicode Standard Anned #9</a>,
1140 * version 13,
1141 * also described in The Unicode Standard, Version 4.0 .<p>
1142 *
1143 * This function takes a piece of plain text containing one or more paragraphs,
1144 * with or without externally specified embedding levels from <i>styled</i>
1145 * text and computes the left-right-directionality of each character.<p>
1146 *
1147 * If the entire text is all of the same directionality, then
1148 * the function may not perform all the steps described by the algorithm,
1149 * i.e., some levels may not be the same as if all steps were performed.
1150 * This is not relevant for unidirectional text.<br>
1151 * For example, in pure LTR text with numbers the numbers would get
1152 * a resolved level of 2 higher than the surrounding text according to
1153 * the algorithm. This implementation may set all resolved levels to
1154 * the same value in such a case.<p>
1155 *
1156 * The text can be composed of multiple paragraphs. Occurrence of a block
1157 * separator in the text terminates a paragraph, and whatever comes next starts
1158 * a new paragraph. The exception to this rule is when a Carriage Return (CR)
1159 * is followed by a Line Feed (LF). Both CR and LF are block separators, but
1160 * in that case, the pair of characters is considered as terminating the
1161 * preceding paragraph, and a new paragraph will be started by a character
1162 * coming after the LF.
1163 *
1164 * @param pBiDi A <code>UBiDi</code> object allocated with <code>ubidi_open()</code>
1165 * which will be set to contain the reordering information,
1166 * especially the resolved levels for all the characters in <code>text</code>.
1167 *
1168 * @param text is a pointer to the text that the Bidi algorithm will be performed on.
1169 * This pointer is stored in the UBiDi object and can be retrieved
1170 * with <code>ubidi_getText()</code>.<br>
1171 * <strong>Note:</strong> the text must be (at least) <code>length</code> long.
1172 *
1173 * @param length is the length of the text; if <code>length==-1</code> then
1174 * the text must be zero-terminated.
1175 *
1176 * @param paraLevel specifies the default level for the text;
1177 * it is typically 0 (LTR) or 1 (RTL).
1178 * If the function shall determine the paragraph level from the text,
1179 * then <code>paraLevel</code> can be set to
1180 * either <code>#UBIDI_DEFAULT_LTR</code>
1181 * or <code>#UBIDI_DEFAULT_RTL</code>; if the text contains multiple
1182 * paragraphs, the paragraph level shall be determined separately for
1183 * each paragraph; if a paragraph does not include any strongly typed
1184 * character, then the desired default is used (0 for LTR or 1 for RTL).
1185 * Any other value between 0 and <code>#UBIDI_MAX_EXPLICIT_LEVEL</code>
1186 * is also valid, with odd levels indicating RTL.
1187 *
1188 * @param embeddingLevels (in) may be used to preset the embedding and override levels,
1189 * ignoring characters like LRE and PDF in the text.
1190 * A level overrides the directional property of its corresponding
1191 * (same index) character if the level has the
1192 * <code>#UBIDI_LEVEL_OVERRIDE</code> bit set.<br><br>
1193 * Except for that bit, it must be
1194 * <code>paraLevel<=embeddingLevels[]<=UBIDI_MAX_EXPLICIT_LEVEL</code>,
1195 * with one exception: a level of zero may be specified for a paragraph
1196 * separator even if <code>paraLevel>0</code> when multiple paragraphs
1197 * are submitted in the same call to <code>ubidi_setPara()</code>.<br><br>
1198 * <strong>Caution: </strong>A copy of this pointer, not of the levels,
1199 * will be stored in the <code>UBiDi</code> object;
1200 * the <code>embeddingLevels</code> array must not be
1201 * deallocated before the <code>UBiDi</code> structure is destroyed or reused,
1202 * and the <code>embeddingLevels</code>
1203 * should not be modified to avoid unexpected results on subsequent Bidi operations.
1204 * However, the <code>ubidi_setPara()</code> and
1205 * <code>ubidi_setLine()</code> functions may modify some or all of the levels.<br><br>
1206 * After the <code>UBiDi</code> object is reused or destroyed, the caller
1207 * must take care of the deallocation of the <code>embeddingLevels</code> array.<br><br>
1208 * <strong>Note:</strong> the <code>embeddingLevels</code> array must be
1209 * at least <code>length</code> long.
1210 * This pointer can be <code>NULL</code> if this
1211 * value is not necessary.
1212 *
1213 * @param pErrorCode must be a valid pointer to an error code value.
1214 * @stable ICU 2.0
1215 */
1216 U_STABLE void U_EXPORT2
1217 ubidi_setPara(UBiDi *pBiDi, const UChar *text, int32_t length,
1218 UBiDiLevel paraLevel, UBiDiLevel *embeddingLevels,
1219 UErrorCode *pErrorCode);
1220
1221 /**
1222 * <code>ubidi_setLine()</code> sets a <code>UBiDi</code> to
1223 * contain the reordering information, especially the resolved levels,
1224 * for all the characters in a line of text. This line of text is
1225 * specified by referring to a <code>UBiDi</code> object representing
1226 * this information for a piece of text containing one or more paragraphs,
1227 * and by specifying a range of indexes in this text.<p>
1228 * In the new line object, the indexes will range from 0 to <code>limit-start-1</code>.<p>
1229 *
1230 * This is used after calling <code>ubidi_setPara()</code>
1231 * for a piece of text, and after line-breaking on that text.
1232 * It is not necessary if each paragraph is treated as a single line.<p>
1233 *
1234 * After line-breaking, rules (L1) and (L2) for the treatment of
1235 * trailing WS and for reordering are performed on
1236 * a <code>UBiDi</code> object that represents a line.<p>
1237 *
1238 * <strong>Important: </strong><code>pLineBiDi</code> shares data with
1239 * <code>pParaBiDi</code>.
1240 * You must destroy or reuse <code>pLineBiDi</code> before <code>pParaBiDi</code>.
1241 * In other words, you must destroy or reuse the <code>UBiDi</code> object for a line
1242 * before the object for its parent paragraph.<p>
1243 *
1244 * The text pointer that was stored in <code>pParaBiDi</code> is also copied,
1245 * and <code>start</code> is added to it so that it points to the beginning of the
1246 * line for this object.
1247 *
1248 * @param pParaBiDi is the parent paragraph object. It must have been set
1249 * by a successful call to ubidi_setPara.
1250 *
1251 * @param start is the line's first index into the text.
1252 *
1253 * @param limit is just behind the line's last index into the text
1254 * (its last index +1).<br>
1255 * It must be <code>0<=start<limit<=</code>containing paragraph limit.
1256 * If the specified line crosses a paragraph boundary, the function
1257 * will terminate with error code U_ILLEGAL_ARGUMENT_ERROR.
1258 *
1259 * @param pLineBiDi is the object that will now represent a line of the text.
1260 *
1261 * @param pErrorCode must be a valid pointer to an error code value.
1262 *
1263 * @see ubidi_setPara
1264 * @see ubidi_getProcessedLength
1265 * @stable ICU 2.0
1266 */
1267 U_STABLE void U_EXPORT2
1268 ubidi_setLine(const UBiDi *pParaBiDi,
1269 int32_t start, int32_t limit,
1270 UBiDi *pLineBiDi,
1271 UErrorCode *pErrorCode);
1272
1273 /**
1274 * Get the directionality of the text.
1275 *
1276 * @param pBiDi is the paragraph or line <code>UBiDi</code> object.
1277 *
1278 * @return a value of <code>UBIDI_LTR</code>, <code>UBIDI_RTL</code>
1279 * or <code>UBIDI_MIXED</code>
1280 * that indicates if the entire text
1281 * represented by this object is unidirectional,
1282 * and which direction, or if it is mixed-directional.
1283 * Note - The value <code>UBIDI_NEUTRAL</code> is never returned from this method.
1284 *
1285 * @see UBiDiDirection
1286 * @stable ICU 2.0
1287 */
1288 U_STABLE UBiDiDirection U_EXPORT2
1289 ubidi_getDirection(const UBiDi *pBiDi);
1290
1291 /**
1292 * Gets the base direction of the text provided according
1293 * to the Unicode Bidirectional Algorithm. The base direction
1294 * is derived from the first character in the string with bidirectional
1295 * character type L, R, or AL. If the first such character has type L,
1296 * <code>UBIDI_LTR</code> is returned. If the first such character has
1297 * type R or AL, <code>UBIDI_RTL</code> is returned. If the string does
1298 * not contain any character of these types, then
1299 * <code>UBIDI_NEUTRAL</code> is returned.
1300 *
1301 * This is a lightweight function for use when only the base direction
1302 * is needed and no further bidi processing of the text is needed.
1303 *
1304 * @param text is a pointer to the text whose base
1305 * direction is needed.
1306 * Note: the text must be (at least) @c length long.
1307 *
1308 * @param length is the length of the text;
1309 * if <code>length==-1</code> then the text
1310 * must be zero-terminated.
1311 *
1312 * @return <code>UBIDI_LTR</code>, <code>UBIDI_RTL</code>,
1313 * <code>UBIDI_NEUTRAL</code>
1314 *
1315 * @see UBiDiDirection
1316 * @stable ICU 4.6
1317 */
1318 U_STABLE UBiDiDirection U_EXPORT2
1319 ubidi_getBaseDirection(const UChar *text, int32_t length );
1320
1321 /**
1322 * Get the pointer to the text.
1323 *
1324 * @param pBiDi is the paragraph or line <code>UBiDi</code> object.
1325 *
1326 * @return The pointer to the text that the UBiDi object was created for.
1327 *
1328 * @see ubidi_setPara
1329 * @see ubidi_setLine
1330 * @stable ICU 2.0
1331 */
1332 U_STABLE const UChar * U_EXPORT2
1333 ubidi_getText(const UBiDi *pBiDi);
1334
1335 /**
1336 * Get the length of the text.
1337 *
1338 * @param pBiDi is the paragraph or line <code>UBiDi</code> object.
1339 *
1340 * @return The length of the text that the UBiDi object was created for.
1341 * @stable ICU 2.0
1342 */
1343 U_STABLE int32_t U_EXPORT2
1344 ubidi_getLength(const UBiDi *pBiDi);
1345
1346 /**
1347 * Get the paragraph level of the text.
1348 *
1349 * @param pBiDi is the paragraph or line <code>UBiDi</code> object.
1350 *
1351 * @return The paragraph level. If there are multiple paragraphs, their
1352 * level may vary if the required paraLevel is UBIDI_DEFAULT_LTR or
1353 * UBIDI_DEFAULT_RTL. In that case, the level of the first paragraph
1354 * is returned.
1355 *
1356 * @see UBiDiLevel
1357 * @see ubidi_getParagraph
1358 * @see ubidi_getParagraphByIndex
1359 * @stable ICU 2.0
1360 */
1361 U_STABLE UBiDiLevel U_EXPORT2
1362 ubidi_getParaLevel(const UBiDi *pBiDi);
1363
1364 /**
1365 * Get the number of paragraphs.
1366 *
1367 * @param pBiDi is the paragraph or line <code>UBiDi</code> object.
1368 *
1369 * @return The number of paragraphs.
1370 * @stable ICU 3.4
1371 */
1372 U_STABLE int32_t U_EXPORT2
1373 ubidi_countParagraphs(UBiDi *pBiDi);
1374
1375 /**
1376 * Get a paragraph, given a position within the text.
1377 * This function returns information about a paragraph.<br>
1378 * Note: if the paragraph index is known, it is more efficient to
1379 * retrieve the paragraph information using ubidi_getParagraphByIndex().<p>
1380 *
1381 * @param pBiDi is the paragraph or line <code>UBiDi</code> object.
1382 *
1383 * @param charIndex is the index of a character within the text, in the
1384 * range <code>[0..ubidi_getProcessedLength(pBiDi)-1]</code>.
1385 *
1386 * @param pParaStart will receive the index of the first character of the
1387 * paragraph in the text.
1388 * This pointer can be <code>NULL</code> if this
1389 * value is not necessary.
1390 *
1391 * @param pParaLimit will receive the limit of the paragraph.
1392 * The l-value that you point to here may be the
1393 * same expression (variable) as the one for
1394 * <code>charIndex</code>.
1395 * This pointer can be <code>NULL</code> if this
1396 * value is not necessary.
1397 *
1398 * @param pParaLevel will receive the level of the paragraph.
1399 * This pointer can be <code>NULL</code> if this
1400 * value is not necessary.
1401 *
1402 * @param pErrorCode must be a valid pointer to an error code value.
1403 *
1404 * @return The index of the paragraph containing the specified position.
1405 *
1406 * @see ubidi_getProcessedLength
1407 * @stable ICU 3.4
1408 */
1409 U_STABLE int32_t U_EXPORT2
1410 ubidi_getParagraph(const UBiDi *pBiDi, int32_t charIndex, int32_t *pParaStart,
1411 int32_t *pParaLimit, UBiDiLevel *pParaLevel,
1412 UErrorCode *pErrorCode);
1413
1414 /**
1415 * Get a paragraph, given the index of this paragraph.
1416 *
1417 * This function returns information about a paragraph.<p>
1418 *
1419 * @param pBiDi is the paragraph <code>UBiDi</code> object.
1420 *
1421 * @param paraIndex is the number of the paragraph, in the
1422 * range <code>[0..ubidi_countParagraphs(pBiDi)-1]</code>.
1423 *
1424 * @param pParaStart will receive the index of the first character of the
1425 * paragraph in the text.
1426 * This pointer can be <code>NULL</code> if this
1427 * value is not necessary.
1428 *
1429 * @param pParaLimit will receive the limit of the paragraph.
1430 * This pointer can be <code>NULL</code> if this
1431 * value is not necessary.
1432 *
1433 * @param pParaLevel will receive the level of the paragraph.
1434 * This pointer can be <code>NULL</code> if this
1435 * value is not necessary.
1436 *
1437 * @param pErrorCode must be a valid pointer to an error code value.
1438 *
1439 * @stable ICU 3.4
1440 */
1441 U_STABLE void U_EXPORT2
1442 ubidi_getParagraphByIndex(const UBiDi *pBiDi, int32_t paraIndex,
1443 int32_t *pParaStart, int32_t *pParaLimit,
1444 UBiDiLevel *pParaLevel, UErrorCode *pErrorCode);
1445
1446 /**
1447 * Get the level for one character.
1448 *
1449 * @param pBiDi is the paragraph or line <code>UBiDi</code> object.
1450 *
1451 * @param charIndex the index of a character. It must be in the range
1452 * [0..ubidi_getProcessedLength(pBiDi)].
1453 *
1454 * @return The level for the character at charIndex (0 if charIndex is not
1455 * in the valid range).
1456 *
1457 * @see UBiDiLevel
1458 * @see ubidi_getProcessedLength
1459 * @stable ICU 2.0
1460 */
1461 U_STABLE UBiDiLevel U_EXPORT2
1462 ubidi_getLevelAt(const UBiDi *pBiDi, int32_t charIndex);
1463
1464 /**
1465 * Get an array of levels for each character.<p>
1466 *
1467 * Note that this function may allocate memory under some
1468 * circumstances, unlike <code>ubidi_getLevelAt()</code>.
1469 *
1470 * @param pBiDi is the paragraph or line <code>UBiDi</code> object, whose
1471 * text length must be strictly positive.
1472 *
1473 * @param pErrorCode must be a valid pointer to an error code value.
1474 *
1475 * @return The levels array for the text,
1476 * or <code>NULL</code> if an error occurs.
1477 *
1478 * @see UBiDiLevel
1479 * @see ubidi_getProcessedLength
1480 * @stable ICU 2.0
1481 */
1482 U_STABLE const UBiDiLevel * U_EXPORT2
1483 ubidi_getLevels(UBiDi *pBiDi, UErrorCode *pErrorCode);
1484
1485 /**
1486 * Get a logical run.
1487 * This function returns information about a run and is used
1488 * to retrieve runs in logical order.<p>
1489 * This is especially useful for line-breaking on a paragraph.
1490 *
1491 * @param pBiDi is the paragraph or line <code>UBiDi</code> object.
1492 *
1493 * @param logicalPosition is a logical position within the source text.
1494 *
1495 * @param pLogicalLimit will receive the limit of the corresponding run.
1496 * The l-value that you point to here may be the
1497 * same expression (variable) as the one for
1498 * <code>logicalPosition</code>.
1499 * This pointer can be <code>NULL</code> if this
1500 * value is not necessary.
1501 *
1502 * @param pLevel will receive the level of the corresponding run.
1503 * This pointer can be <code>NULL</code> if this
1504 * value is not necessary.
1505 *
1506 * @see ubidi_getProcessedLength
1507 * @stable ICU 2.0
1508 */
1509 U_STABLE void U_EXPORT2
1510 ubidi_getLogicalRun(const UBiDi *pBiDi, int32_t logicalPosition,
1511 int32_t *pLogicalLimit, UBiDiLevel *pLevel);
1512
1513 /**
1514 * Get the number of runs.
1515 * This function may invoke the actual reordering on the
1516 * <code>UBiDi</code> object, after <code>ubidi_setPara()</code>
1517 * may have resolved only the levels of the text. Therefore,
1518 * <code>ubidi_countRuns()</code> may have to allocate memory,
1519 * and may fail doing so.
1520 *
1521 * @param pBiDi is the paragraph or line <code>UBiDi</code> object.
1522 *
1523 * @param pErrorCode must be a valid pointer to an error code value.
1524 *
1525 * @return The number of runs.
1526 * @stable ICU 2.0
1527 */
1528 U_STABLE int32_t U_EXPORT2
1529 ubidi_countRuns(UBiDi *pBiDi, UErrorCode *pErrorCode);
1530
1531 /**
1532 * Get one run's logical start, length, and directionality,
1533 * which can be 0 for LTR or 1 for RTL.
1534 * In an RTL run, the character at the logical start is
1535 * visually on the right of the displayed run.
1536 * The length is the number of characters in the run.<p>
1537 * <code>ubidi_countRuns()</code> should be called
1538 * before the runs are retrieved.
1539 *
1540 * @param pBiDi is the paragraph or line <code>UBiDi</code> object.
1541 *
1542 * @param runIndex is the number of the run in visual order, in the
1543 * range <code>[0..ubidi_countRuns(pBiDi)-1]</code>.
1544 *
1545 * @param pLogicalStart is the first logical character index in the text.
1546 * The pointer may be <code>NULL</code> if this index is not needed.
1547 *
1548 * @param pLength is the number of characters (at least one) in the run.
1549 * The pointer may be <code>NULL</code> if this is not needed.
1550 *
1551 * @return the directionality of the run,
1552 * <code>UBIDI_LTR==0</code> or <code>UBIDI_RTL==1</code>,
1553 * never <code>UBIDI_MIXED</code>,
1554 * never <code>UBIDI_NEUTRAL</code>.
1555 *
1556 * @see ubidi_countRuns
1557 *
1558 * Example:
1559 * <pre>
1560 * \code
1561 * int32_t i, count=ubidi_countRuns(pBiDi),
1562 * logicalStart, visualIndex=0, length;
1563 * for(i=0; i<count; ++i) {
1564 * if(UBIDI_LTR==ubidi_getVisualRun(pBiDi, i, &logicalStart, &length)) {
1565 * do { // LTR
1566 * show_char(text[logicalStart++], visualIndex++);
1567 * } while(--length>0);
1568 * } else {
1569 * logicalStart+=length; // logicalLimit
1570 * do { // RTL
1571 * show_char(text[--logicalStart], visualIndex++);
1572 * } while(--length>0);
1573 * }
1574 * }
1575 *\endcode
1576 * </pre>
1577 *
1578 * Note that in right-to-left runs, code like this places
1579 * second surrogates before first ones (which is generally a bad idea)
1580 * and combining characters before base characters.
1581 * <p>
1582 * Use of <code>ubidi_writeReordered()</code>, optionally with the
1583 * <code>#UBIDI_KEEP_BASE_COMBINING</code> option, can be considered in order
1584 * to avoid these issues.
1585 * @stable ICU 2.0
1586 */
1587 U_STABLE UBiDiDirection U_EXPORT2
1588 ubidi_getVisualRun(UBiDi *pBiDi, int32_t runIndex,
1589 int32_t *pLogicalStart, int32_t *pLength);
1590
1591 /**
1592 * Get the visual position from a logical text position.
1593 * If such a mapping is used many times on the same
1594 * <code>UBiDi</code> object, then calling
1595 * <code>ubidi_getLogicalMap()</code> is more efficient.<p>
1596 *
1597 * The value returned may be <code>#UBIDI_MAP_NOWHERE</code> if there is no
1598 * visual position because the corresponding text character is a Bidi control
1599 * removed from output by the option <code>#UBIDI_OPTION_REMOVE_CONTROLS</code>.
1600 * <p>
1601 * When the visual output is altered by using options of
1602 * <code>ubidi_writeReordered()</code> such as <code>UBIDI_INSERT_LRM_FOR_NUMERIC</code>,
1603 * <code>UBIDI_KEEP_BASE_COMBINING</code>, <code>UBIDI_OUTPUT_REVERSE</code>,
1604 * <code>UBIDI_REMOVE_BIDI_CONTROLS</code>, the visual position returned may not
1605 * be correct. It is advised to use, when possible, reordering options
1606 * such as <code>UBIDI_OPTION_INSERT_MARKS</code> and <code>UBIDI_OPTION_REMOVE_CONTROLS</code>.
1607 * <p>
1608 * Note that in right-to-left runs, this mapping places
1609 * second surrogates before first ones (which is generally a bad idea)
1610 * and combining characters before base characters.
1611 * Use of <code>ubidi_writeReordered()</code>, optionally with the
1612 * <code>#UBIDI_KEEP_BASE_COMBINING</code> option can be considered instead
1613 * of using the mapping, in order to avoid these issues.
1614 *
1615 * @param pBiDi is the paragraph or line <code>UBiDi</code> object.
1616 *
1617 * @param logicalIndex is the index of a character in the text.
1618 *
1619 * @param pErrorCode must be a valid pointer to an error code value.
1620 *
1621 * @return The visual position of this character.
1622 *
1623 * @see ubidi_getLogicalMap
1624 * @see ubidi_getLogicalIndex
1625 * @see ubidi_getProcessedLength
1626 * @stable ICU 2.0
1627 */
1628 U_STABLE int32_t U_EXPORT2
1629 ubidi_getVisualIndex(UBiDi *pBiDi, int32_t logicalIndex, UErrorCode *pErrorCode);
1630
1631 /**
1632 * Get the logical text position from a visual position.
1633 * If such a mapping is used many times on the same
1634 * <code>UBiDi</code> object, then calling
1635 * <code>ubidi_getVisualMap()</code> is more efficient.<p>
1636 *
1637 * The value returned may be <code>#UBIDI_MAP_NOWHERE</code> if there is no
1638 * logical position because the corresponding text character is a Bidi mark
1639 * inserted in the output by option <code>#UBIDI_OPTION_INSERT_MARKS</code>.
1640 * <p>
1641 * This is the inverse function to <code>ubidi_getVisualIndex()</code>.
1642 * <p>
1643 * When the visual output is altered by using options of
1644 * <code>ubidi_writeReordered()</code> such as <code>UBIDI_INSERT_LRM_FOR_NUMERIC</code>,
1645 * <code>UBIDI_KEEP_BASE_COMBINING</code>, <code>UBIDI_OUTPUT_REVERSE</code>,
1646 * <code>UBIDI_REMOVE_BIDI_CONTROLS</code>, the logical position returned may not
1647 * be correct. It is advised to use, when possible, reordering options
1648 * such as <code>UBIDI_OPTION_INSERT_MARKS</code> and <code>UBIDI_OPTION_REMOVE_CONTROLS</code>.
1649 *
1650 * @param pBiDi is the paragraph or line <code>UBiDi</code> object.
1651 *
1652 * @param visualIndex is the visual position of a character.
1653 *
1654 * @param pErrorCode must be a valid pointer to an error code value.
1655 *
1656 * @return The index of this character in the text.
1657 *
1658 * @see ubidi_getVisualMap
1659 * @see ubidi_getVisualIndex
1660 * @see ubidi_getResultLength
1661 * @stable ICU 2.0
1662 */
1663 U_STABLE int32_t U_EXPORT2
1664 ubidi_getLogicalIndex(UBiDi *pBiDi, int32_t visualIndex, UErrorCode *pErrorCode);
1665
1666 /**
1667 * Get a logical-to-visual index map (array) for the characters in the UBiDi
1668 * (paragraph or line) object.
1669 * <p>
1670 * Some values in the map may be <code>#UBIDI_MAP_NOWHERE</code> if the
1671 * corresponding text characters are Bidi controls removed from the visual
1672 * output by the option <code>#UBIDI_OPTION_REMOVE_CONTROLS</code>.
1673 * <p>
1674 * When the visual output is altered by using options of
1675 * <code>ubidi_writeReordered()</code> such as <code>UBIDI_INSERT_LRM_FOR_NUMERIC</code>,
1676 * <code>UBIDI_KEEP_BASE_COMBINING</code>, <code>UBIDI_OUTPUT_REVERSE</code>,
1677 * <code>UBIDI_REMOVE_BIDI_CONTROLS</code>, the visual positions returned may not
1678 * be correct. It is advised to use, when possible, reordering options
1679 * such as <code>UBIDI_OPTION_INSERT_MARKS</code> and <code>UBIDI_OPTION_REMOVE_CONTROLS</code>.
1680 * <p>
1681 * Note that in right-to-left runs, this mapping places
1682 * second surrogates before first ones (which is generally a bad idea)
1683 * and combining characters before base characters.
1684 * Use of <code>ubidi_writeReordered()</code>, optionally with the
1685 * <code>#UBIDI_KEEP_BASE_COMBINING</code> option can be considered instead
1686 * of using the mapping, in order to avoid these issues.
1687 *
1688 * @param pBiDi is the paragraph or line <code>UBiDi</code> object.
1689 *
1690 * @param indexMap is a pointer to an array of <code>ubidi_getProcessedLength()</code>
1691 * indexes which will reflect the reordering of the characters.
1692 * If option <code>#UBIDI_OPTION_INSERT_MARKS</code> is set, the number
1693 * of elements allocated in <code>indexMap</code> must be no less than
1694 * <code>ubidi_getResultLength()</code>.
1695 * The array does not need to be initialized.<br><br>
1696 * The index map will result in <code>indexMap[logicalIndex]==visualIndex</code>.
1697 *
1698 * @param pErrorCode must be a valid pointer to an error code value.
1699 *
1700 * @see ubidi_getVisualMap
1701 * @see ubidi_getVisualIndex
1702 * @see ubidi_getProcessedLength
1703 * @see ubidi_getResultLength
1704 * @stable ICU 2.0
1705 */
1706 U_STABLE void U_EXPORT2
1707 ubidi_getLogicalMap(UBiDi *pBiDi, int32_t *indexMap, UErrorCode *pErrorCode);
1708
1709 /**
1710 * Get a visual-to-logical index map (array) for the characters in the UBiDi
1711 * (paragraph or line) object.
1712 * <p>
1713 * Some values in the map may be <code>#UBIDI_MAP_NOWHERE</code> if the
1714 * corresponding text characters are Bidi marks inserted in the visual output
1715 * by the option <code>#UBIDI_OPTION_INSERT_MARKS</code>.
1716 * <p>
1717 * When the visual output is altered by using options of
1718 * <code>ubidi_writeReordered()</code> such as <code>UBIDI_INSERT_LRM_FOR_NUMERIC</code>,
1719 * <code>UBIDI_KEEP_BASE_COMBINING</code>, <code>UBIDI_OUTPUT_REVERSE</code>,
1720 * <code>UBIDI_REMOVE_BIDI_CONTROLS</code>, the logical positions returned may not
1721 * be correct. It is advised to use, when possible, reordering options
1722 * such as <code>UBIDI_OPTION_INSERT_MARKS</code> and <code>UBIDI_OPTION_REMOVE_CONTROLS</code>.
1723 *
1724 * @param pBiDi is the paragraph or line <code>UBiDi</code> object.
1725 *
1726 * @param indexMap is a pointer to an array of <code>ubidi_getResultLength()</code>
1727 * indexes which will reflect the reordering of the characters.
1728 * If option <code>#UBIDI_OPTION_REMOVE_CONTROLS</code> is set, the number
1729 * of elements allocated in <code>indexMap</code> must be no less than
1730 * <code>ubidi_getProcessedLength()</code>.
1731 * The array does not need to be initialized.<br><br>
1732 * The index map will result in <code>indexMap[visualIndex]==logicalIndex</code>.
1733 *
1734 * @param pErrorCode must be a valid pointer to an error code value.
1735 *
1736 * @see ubidi_getLogicalMap
1737 * @see ubidi_getLogicalIndex
1738 * @see ubidi_getProcessedLength
1739 * @see ubidi_getResultLength
1740 * @stable ICU 2.0
1741 */
1742 U_STABLE void U_EXPORT2
1743 ubidi_getVisualMap(UBiDi *pBiDi, int32_t *indexMap, UErrorCode *pErrorCode);
1744
1745 /**
1746 * This is a convenience function that does not use a UBiDi object.
1747 * It is intended to be used for when an application has determined the levels
1748 * of objects (character sequences) and just needs to have them reordered (L2).
1749 * This is equivalent to using <code>ubidi_getLogicalMap()</code> on a
1750 * <code>UBiDi</code> object.
1751 *
1752 * @param levels is an array with <code>length</code> levels that have been determined by
1753 * the application.
1754 *
1755 * @param length is the number of levels in the array, or, semantically,
1756 * the number of objects to be reordered.
1757 * It must be <code>length>0</code>.
1758 *
1759 * @param indexMap is a pointer to an array of <code>length</code>
1760 * indexes which will reflect the reordering of the characters.
1761 * The array does not need to be initialized.<p>
1762 * The index map will result in <code>indexMap[logicalIndex]==visualIndex</code>.
1763 * @stable ICU 2.0
1764 */
1765 U_STABLE void U_EXPORT2
1766 ubidi_reorderLogical(const UBiDiLevel *levels, int32_t length, int32_t *indexMap);
1767
1768 /**
1769 * This is a convenience function that does not use a UBiDi object.
1770 * It is intended to be used for when an application has determined the levels
1771 * of objects (character sequences) and just needs to have them reordered (L2).
1772 * This is equivalent to using <code>ubidi_getVisualMap()</code> on a
1773 * <code>UBiDi</code> object.
1774 *
1775 * @param levels is an array with <code>length</code> levels that have been determined by
1776 * the application.
1777 *
1778 * @param length is the number of levels in the array, or, semantically,
1779 * the number of objects to be reordered.
1780 * It must be <code>length>0</code>.
1781 *
1782 * @param indexMap is a pointer to an array of <code>length</code>
1783 * indexes which will reflect the reordering of the characters.
1784 * The array does not need to be initialized.<p>
1785 * The index map will result in <code>indexMap[visualIndex]==logicalIndex</code>.
1786 * @stable ICU 2.0
1787 */
1788 U_STABLE void U_EXPORT2
1789 ubidi_reorderVisual(const UBiDiLevel *levels, int32_t length, int32_t *indexMap);
1790
1791 /**
1792 * Invert an index map.
1793 * The index mapping of the first map is inverted and written to
1794 * the second one.
1795 *
1796 * @param srcMap is an array with <code>length</code> elements
1797 * which defines the original mapping from a source array containing
1798 * <code>length</code> elements to a destination array.
1799 * Some elements of the source array may have no mapping in the
1800 * destination array. In that case, their value will be
1801 * the special value <code>UBIDI_MAP_NOWHERE</code>.
1802 * All elements must be >=0 or equal to <code>UBIDI_MAP_NOWHERE</code>.
1803 * Some elements may have a value >= <code>length</code>, if the
1804 * destination array has more elements than the source array.
1805 * There must be no duplicate indexes (two or more elements with the
1806 * same value except <code>UBIDI_MAP_NOWHERE</code>).
1807 *
1808 * @param destMap is an array with a number of elements equal to 1 + the highest
1809 * value in <code>srcMap</code>.
1810 * <code>destMap</code> will be filled with the inverse mapping.
1811 * If element with index i in <code>srcMap</code> has a value k different
1812 * from <code>UBIDI_MAP_NOWHERE</code>, this means that element i of
1813 * the source array maps to element k in the destination array.
1814 * The inverse map will have value i in its k-th element.
1815 * For all elements of the destination array which do not map to
1816 * an element in the source array, the corresponding element in the
1817 * inverse map will have a value equal to <code>UBIDI_MAP_NOWHERE</code>.
1818 *
1819 * @param length is the length of each array.
1820 * @see UBIDI_MAP_NOWHERE
1821 * @stable ICU 2.0
1822 */
1823 U_STABLE void U_EXPORT2
1824 ubidi_invertMap(const int32_t *srcMap, int32_t *destMap, int32_t length);
1825
1826 /** option flags for ubidi_writeReordered() */
1827
1828 /**
1829 * option bit for ubidi_writeReordered():
1830 * keep combining characters after their base characters in RTL runs
1831 *
1832 * @see ubidi_writeReordered
1833 * @stable ICU 2.0
1834 */
1835 #define UBIDI_KEEP_BASE_COMBINING 1
1836
1837 /**
1838 * option bit for ubidi_writeReordered():
1839 * replace characters with the "mirrored" property in RTL runs
1840 * by their mirror-image mappings
1841 *
1842 * @see ubidi_writeReordered
1843 * @stable ICU 2.0
1844 */
1845 #define UBIDI_DO_MIRRORING 2
1846
1847 /**
1848 * option bit for ubidi_writeReordered():
1849 * surround the run with LRMs if necessary;
1850 * this is part of the approximate "inverse Bidi" algorithm
1851 *
1852 * <p>This option does not imply corresponding adjustment of the index
1853 * mappings.</p>
1854 *
1855 * @see ubidi_setInverse
1856 * @see ubidi_writeReordered
1857 * @stable ICU 2.0
1858 */
1859 #define UBIDI_INSERT_LRM_FOR_NUMERIC 4
1860
1861 /**
1862 * option bit for ubidi_writeReordered():
1863 * remove Bidi control characters
1864 * (this does not affect #UBIDI_INSERT_LRM_FOR_NUMERIC)
1865 *
1866 * <p>This option does not imply corresponding adjustment of the index
1867 * mappings.</p>
1868 *
1869 * @see ubidi_writeReordered
1870 * @stable ICU 2.0
1871 */
1872 #define UBIDI_REMOVE_BIDI_CONTROLS 8
1873
1874 /**
1875 * option bit for ubidi_writeReordered():
1876 * write the output in reverse order
1877 *
1878 * <p>This has the same effect as calling <code>ubidi_writeReordered()</code>
1879 * first without this option, and then calling
1880 * <code>ubidi_writeReverse()</code> without mirroring.
1881 * Doing this in the same step is faster and avoids a temporary buffer.
1882 * An example for using this option is output to a character terminal that
1883 * is designed for RTL scripts and stores text in reverse order.</p>
1884 *
1885 * @see ubidi_writeReordered
1886 * @stable ICU 2.0
1887 */
1888 #define UBIDI_OUTPUT_REVERSE 16
1889
1890 /**
1891 * Get the length of the source text processed by the last call to
1892 * <code>ubidi_setPara()</code>. This length may be different from the length
1893 * of the source text if option <code>#UBIDI_OPTION_STREAMING</code>
1894 * has been set.
1895 * <br>
1896 * Note that whenever the length of the text affects the execution or the
1897 * result of a function, it is the processed length which must be considered,
1898 * except for <code>ubidi_setPara</code> (which receives unprocessed source
1899 * text) and <code>ubidi_getLength</code> (which returns the original length
1900 * of the source text).<br>
1901 * In particular, the processed length is the one to consider in the following
1902 * cases:
1903 * <ul>
1904 * <li>maximum value of the <code>limit</code> argument of
1905 * <code>ubidi_setLine</code></li>
1906 * <li>maximum value of the <code>charIndex</code> argument of
1907 * <code>ubidi_getParagraph</code></li>
1908 * <li>maximum value of the <code>charIndex</code> argument of
1909 * <code>ubidi_getLevelAt</code></li>
1910 * <li>number of elements in the array returned by <code>ubidi_getLevels</code></li>
1911 * <li>maximum value of the <code>logicalStart</code> argument of
1912 * <code>ubidi_getLogicalRun</code></li>
1913 * <li>maximum value of the <code>logicalIndex</code> argument of
1914 * <code>ubidi_getVisualIndex</code></li>
1915 * <li>number of elements filled in the <code>*indexMap</code> argument of
1916 * <code>ubidi_getLogicalMap</code></li>
1917 * <li>length of text processed by <code>ubidi_writeReordered</code></li>
1918 * </ul>
1919 *
1920 * @param pBiDi is the paragraph <code>UBiDi</code> object.
1921 *
1922 * @return The length of the part of the source text processed by
1923 * the last call to <code>ubidi_setPara</code>.
1924 * @see ubidi_setPara
1925 * @see UBIDI_OPTION_STREAMING
1926 * @stable ICU 3.6
1927 */
1928 U_STABLE int32_t U_EXPORT2
1929 ubidi_getProcessedLength(const UBiDi *pBiDi);
1930
1931 /**
1932 * Get the length of the reordered text resulting from the last call to
1933 * <code>ubidi_setPara()</code>. This length may be different from the length
1934 * of the source text if option <code>#UBIDI_OPTION_INSERT_MARKS</code>
1935 * or option <code>#UBIDI_OPTION_REMOVE_CONTROLS</code> has been set.
1936 * <br>
1937 * This resulting length is the one to consider in the following cases:
1938 * <ul>
1939 * <li>maximum value of the <code>visualIndex</code> argument of
1940 * <code>ubidi_getLogicalIndex</code></li>
1941 * <li>number of elements of the <code>*indexMap</code> argument of
1942 * <code>ubidi_getVisualMap</code></li>
1943 * </ul>
1944 * Note that this length stays identical to the source text length if
1945 * Bidi marks are inserted or removed using option bits of
1946 * <code>ubidi_writeReordered</code>, or if option
1947 * <code>#UBIDI_REORDER_INVERSE_NUMBERS_AS_L</code> has been set.
1948 *
1949 * @param pBiDi is the paragraph <code>UBiDi</code> object.
1950 *
1951 * @return The length of the reordered text resulting from
1952 * the last call to <code>ubidi_setPara</code>.
1953 * @see ubidi_setPara
1954 * @see UBIDI_OPTION_INSERT_MARKS
1955 * @see UBIDI_OPTION_REMOVE_CONTROLS
1956 * @stable ICU 3.6
1957 */
1958 U_STABLE int32_t U_EXPORT2
1959 ubidi_getResultLength(const UBiDi *pBiDi);
1960
1961 U_CDECL_BEGIN
1962 /**
1963 * value returned by <code>UBiDiClassCallback</code> callbacks when
1964 * there is no need to override the standard Bidi class for a given code point.
1965 * @see UBiDiClassCallback
1966 * @stable ICU 3.6
1967 */
1968 #define U_BIDI_CLASS_DEFAULT U_CHAR_DIRECTION_COUNT
1969
1970 /**
1971 * Callback type declaration for overriding default Bidi class values with
1972 * custom ones.
1973 * <p>Usually, the function pointer will be propagated to a <code>UBiDi</code>
1974 * object by calling the <code>ubidi_setClassCallback()</code> function;
1975 * then the callback will be invoked by the UBA implementation any time the
1976 * class of a character is to be determined.</p>
1977 *
1978 * @param context is a pointer to the callback private data.
1979 *
1980 * @param c is the code point to get a Bidi class for.
1981 *
1982 * @return The directional property / Bidi class for the given code point
1983 * <code>c</code> if the default class has been overridden, or
1984 * <code>#U_BIDI_CLASS_DEFAULT</code> if the standard Bidi class value
1985 * for <code>c</code> is to be used.
1986 * @see ubidi_setClassCallback
1987 * @see ubidi_getClassCallback
1988 * @stable ICU 3.6
1989 */
1990 typedef UCharDirection U_CALLCONV
1991 UBiDiClassCallback(const void *context, UChar32 c);
1992
1993 U_CDECL_END
1994
1995 /**
1996 * Retrieve the Bidi class for a given code point.
1997 * <p>If a <code>#UBiDiClassCallback</code> callback is defined and returns a
1998 * value other than <code>#U_BIDI_CLASS_DEFAULT</code>, that value is used;
1999 * otherwise the default class determination mechanism is invoked.</p>
2000 *
2001 * @param pBiDi is the paragraph <code>UBiDi</code> object.
2002 *
2003 * @param c is the code point whose Bidi class must be retrieved.
2004 *
2005 * @return The Bidi class for character <code>c</code> based
2006 * on the given <code>pBiDi</code> instance.
2007 * @see UBiDiClassCallback
2008 * @stable ICU 3.6
2009 */
2010 U_STABLE UCharDirection U_EXPORT2
2011 ubidi_getCustomizedClass(UBiDi *pBiDi, UChar32 c);
2012
2013 /**
2014 * Set the callback function and callback data used by the UBA
2015 * implementation for Bidi class determination.
2016 * <p>This may be useful for assigning Bidi classes to PUA characters, or
2017 * for special application needs. For instance, an application may want to
2018 * handle all spaces like L or R characters (according to the base direction)
2019 * when creating the visual ordering of logical lines which are part of a report
2020 * organized in columns: there should not be interaction between adjacent
2021 * cells.<p>
2022 *
2023 * @param pBiDi is the paragraph <code>UBiDi</code> object.
2024 *
2025 * @param newFn is the new callback function pointer.
2026 *
2027 * @param newContext is the new callback context pointer. This can be NULL.
2028 *
2029 * @param oldFn fillin: Returns the old callback function pointer. This can be
2030 * NULL.
2031 *
2032 * @param oldContext fillin: Returns the old callback's context. This can be
2033 * NULL.
2034 *
2035 * @param pErrorCode must be a valid pointer to an error code value.
2036 *
2037 * @see ubidi_getClassCallback
2038 * @stable ICU 3.6
2039 */
2040 U_STABLE void U_EXPORT2
2041 ubidi_setClassCallback(UBiDi *pBiDi, UBiDiClassCallback *newFn,
2042 const void *newContext, UBiDiClassCallback **oldFn,
2043 const void **oldContext, UErrorCode *pErrorCode);
2044
2045 /**
2046 * Get the current callback function used for Bidi class determination.
2047 *
2048 * @param pBiDi is the paragraph <code>UBiDi</code> object.
2049 *
2050 * @param fn fillin: Returns the callback function pointer.
2051 *
2052 * @param context fillin: Returns the callback's private context.
2053 *
2054 * @see ubidi_setClassCallback
2055 * @stable ICU 3.6
2056 */
2057 U_STABLE void U_EXPORT2
2058 ubidi_getClassCallback(UBiDi *pBiDi, UBiDiClassCallback **fn, const void **context);
2059
2060 /**
2061 * Take a <code>UBiDi</code> object containing the reordering
2062 * information for a piece of text (one or more paragraphs) set by
2063 * <code>ubidi_setPara()</code> or for a line of text set by
2064 * <code>ubidi_setLine()</code> and write a reordered string to the
2065 * destination buffer.
2066 *
2067 * This function preserves the integrity of characters with multiple
2068 * code units and (optionally) combining characters.
2069 * Characters in RTL runs can be replaced by mirror-image characters
2070 * in the destination buffer. Note that "real" mirroring has
2071 * to be done in a rendering engine by glyph selection
2072 * and that for many "mirrored" characters there are no
2073 * Unicode characters as mirror-image equivalents.
2074 * There are also options to insert or remove Bidi control
2075 * characters; see the description of the <code>destSize</code>
2076 * and <code>options</code> parameters and of the option bit flags.
2077 *
2078 * @param pBiDi A pointer to a <code>UBiDi</code> object that
2079 * is set by <code>ubidi_setPara()</code> or
2080 * <code>ubidi_setLine()</code> and contains the reordering
2081 * information for the text that it was defined for,
2082 * as well as a pointer to that text.<br><br>
2083 * The text was aliased (only the pointer was stored
2084 * without copying the contents) and must not have been modified
2085 * since the <code>ubidi_setPara()</code> call.
2086 *
2087 * @param dest A pointer to where the reordered text is to be copied.
2088 * The source text and <code>dest[destSize]</code>
2089 * must not overlap.
2090 *
2091 * @param destSize The size of the <code>dest</code> buffer,
2092 * in number of UChars.
2093 * If the <code>UBIDI_INSERT_LRM_FOR_NUMERIC</code>
2094 * option is set, then the destination length could be
2095 * as large as
2096 * <code>ubidi_getLength(pBiDi)+2*ubidi_countRuns(pBiDi)</code>.
2097 * If the <code>UBIDI_REMOVE_BIDI_CONTROLS</code> option
2098 * is set, then the destination length may be less than
2099 * <code>ubidi_getLength(pBiDi)</code>.
2100 * If none of these options is set, then the destination length
2101 * will be exactly <code>ubidi_getProcessedLength(pBiDi)</code>.
2102 *
2103 * @param options A bit set of options for the reordering that control
2104 * how the reordered text is written.
2105 * The options include mirroring the characters on a code
2106 * point basis and inserting LRM characters, which is used
2107 * especially for transforming visually stored text
2108 * to logically stored text (although this is still an
2109 * imperfect implementation of an "inverse Bidi" algorithm
2110 * because it uses the "forward Bidi" algorithm at its core).
2111 * The available options are:
2112 * <code>#UBIDI_DO_MIRRORING</code>,
2113 * <code>#UBIDI_INSERT_LRM_FOR_NUMERIC</code>,
2114 * <code>#UBIDI_KEEP_BASE_COMBINING</code>,
2115 * <code>#UBIDI_OUTPUT_REVERSE</code>,
2116 * <code>#UBIDI_REMOVE_BIDI_CONTROLS</code>
2117 *
2118 * @param pErrorCode must be a valid pointer to an error code value.
2119 *
2120 * @return The length of the output string.
2121 *
2122 * @see ubidi_getProcessedLength
2123 * @stable ICU 2.0
2124 */
2125 U_STABLE int32_t U_EXPORT2
2126 ubidi_writeReordered(UBiDi *pBiDi,
2127 UChar *dest, int32_t destSize,
2128 uint16_t options,
2129 UErrorCode *pErrorCode);
2130
2131 /**
2132 * Reverse a Right-To-Left run of Unicode text.
2133 *
2134 * This function preserves the integrity of characters with multiple
2135 * code units and (optionally) combining characters.
2136 * Characters can be replaced by mirror-image characters
2137 * in the destination buffer. Note that "real" mirroring has
2138 * to be done in a rendering engine by glyph selection
2139 * and that for many "mirrored" characters there are no
2140 * Unicode characters as mirror-image equivalents.
2141 * There are also options to insert or remove Bidi control
2142 * characters.
2143 *
2144 * This function is the implementation for reversing RTL runs as part
2145 * of <code>ubidi_writeReordered()</code>. For detailed descriptions
2146 * of the parameters, see there.
2147 * Since no Bidi controls are inserted here, the output string length
2148 * will never exceed <code>srcLength</code>.
2149 *
2150 * @see ubidi_writeReordered
2151 *
2152 * @param src A pointer to the RTL run text.
2153 *
2154 * @param srcLength The length of the RTL run.
2155 *
2156 * @param dest A pointer to where the reordered text is to be copied.
2157 * <code>src[srcLength]</code> and <code>dest[destSize]</code>
2158 * must not overlap.
2159 *
2160 * @param destSize The size of the <code>dest</code> buffer,
2161 * in number of UChars.
2162 * If the <code>UBIDI_REMOVE_BIDI_CONTROLS</code> option
2163 * is set, then the destination length may be less than
2164 * <code>srcLength</code>.
2165 * If this option is not set, then the destination length
2166 * will be exactly <code>srcLength</code>.
2167 *
2168 * @param options A bit set of options for the reordering that control
2169 * how the reordered text is written.
2170 * See the <code>options</code> parameter in <code>ubidi_writeReordered()</code>.
2171 *
2172 * @param pErrorCode must be a valid pointer to an error code value.
2173 *
2174 * @return The length of the output string.
2175 * @stable ICU 2.0
2176 */
2177 U_STABLE int32_t U_EXPORT2
2178 ubidi_writeReverse(const UChar *src, int32_t srcLength,
2179 UChar *dest, int32_t destSize,
2180 uint16_t options,
2181 UErrorCode *pErrorCode);
2182
2183 /*#define BIDI_SAMPLE_CODE*/
2184 /*@}*/
2185
2186 #endif

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