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Issue 18836004: Move ICU headers from public/{common,i18n} to source/{common,i18n} (Closed) Base URL: https://chromium.googlesource.com/chromium/deps/icu46.git@master
Patch Set: same as ps #3. retry uploading Created 7 years, 5 months ago
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1 /*
2 ******************************************************************************
3 *
4 * Copyright (C) 1999-2010, 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 *pStyleRun Limit,
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 ma y
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 ma y
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</co de>).
388 * @stable ICU 2.0
389 */
390 #define UBIDI_MAX_EXPLICIT_LEVEL 61
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 * @draft 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 o f
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()</c ode>
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 alloca tion
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 implemen tation.<br><br>
520 * The number of runs depends on the actual text and maybe anywhere betwe en
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 sourc e
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</c ode>
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 Visu al
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 Visua l
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."</l i>
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 th e
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 larg e
979 * text object in parts.
980 * The results of the successive calls are expected to be concatenated by th e
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 meaning ful
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 t o
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 followin g:
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</co de>.
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 * Perform the Unicode Bidi algorithm. It is defined in the
1049 * <a href="http://www.unicode.org/unicode/reports/tr9/">Unicode Standard Anned #9</a>,
1050 * version 13,
1051 * also described in The Unicode Standard, Version 4.0 .<p>
1052 *
1053 * This function takes a piece of plain text containing one or more paragraphs,
1054 * with or without externally specified embedding levels from <i>styled</i>
1055 * text and computes the left-right-directionality of each character.<p>
1056 *
1057 * If the entire text is all of the same directionality, then
1058 * the function may not perform all the steps described by the algorithm,
1059 * i.e., some levels may not be the same as if all steps were performed.
1060 * This is not relevant for unidirectional text.<br>
1061 * For example, in pure LTR text with numbers the numbers would get
1062 * a resolved level of 2 higher than the surrounding text according to
1063 * the algorithm. This implementation may set all resolved levels to
1064 * the same value in such a case.<p>
1065 *
1066 * The text can be composed of multiple paragraphs. Occurrence of a block
1067 * separator in the text terminates a paragraph, and whatever comes next starts
1068 * a new paragraph. The exception to this rule is when a Carriage Return (CR)
1069 * is followed by a Line Feed (LF). Both CR and LF are block separators, but
1070 * in that case, the pair of characters is considered as terminating the
1071 * preceding paragraph, and a new paragraph will be started by a character
1072 * coming after the LF.
1073 *
1074 * @param pBiDi A <code>UBiDi</code> object allocated with <code>ubidi_open()</c ode>
1075 * which will be set to contain the reordering information,
1076 * especially the resolved levels for all the characters in <code>text</c ode>.
1077 *
1078 * @param text is a pointer to the text that the Bidi algorithm will be performe d on.
1079 * This pointer is stored in the UBiDi object and can be retrieved
1080 * with <code>ubidi_getText()</code>.<br>
1081 * <strong>Note:</strong> the text must be (at least) <code>length</code> long.
1082 *
1083 * @param length is the length of the text; if <code>length==-1</code> then
1084 * the text must be zero-terminated.
1085 *
1086 * @param paraLevel specifies the default level for the text;
1087 * it is typically 0 (LTR) or 1 (RTL).
1088 * If the function shall determine the paragraph level from the text,
1089 * then <code>paraLevel</code> can be set to
1090 * either <code>#UBIDI_DEFAULT_LTR</code>
1091 * or <code>#UBIDI_DEFAULT_RTL</code>; if the text contains multiple
1092 * paragraphs, the paragraph level shall be determined separately for
1093 * each paragraph; if a paragraph does not include any strongly typed
1094 * character, then the desired default is used (0 for LTR or 1 for RTL).
1095 * Any other value between 0 and <code>#UBIDI_MAX_EXPLICIT_LEVEL</code>
1096 * is also valid, with odd levels indicating RTL.
1097 *
1098 * @param embeddingLevels (in) may be used to preset the embedding and override levels,
1099 * ignoring characters like LRE and PDF in the text.
1100 * A level overrides the directional property of its corresponding
1101 * (same index) character if the level has the
1102 * <code>#UBIDI_LEVEL_OVERRIDE</code> bit set.<br><br>
1103 * Except for that bit, it must be
1104 * <code>paraLevel<=embeddingLevels[]<=UBIDI_MAX_EXPLICIT_LEVEL</code>,
1105 * with one exception: a level of zero may be specified for a paragraph
1106 * separator even if <code>paraLevel>0</code> when multiple paragraphs
1107 * are submitted in the same call to <code>ubidi_setPara()</code>.<br><br >
1108 * <strong>Caution: </strong>A copy of this pointer, not of the levels,
1109 * will be stored in the <code>UBiDi</code> object;
1110 * the <code>embeddingLevels</code> array must not be
1111 * deallocated before the <code>UBiDi</code> structure is destroyed or re used,
1112 * and the <code>embeddingLevels</code>
1113 * should not be modified to avoid unexpected results on subsequent Bidi operations.
1114 * However, the <code>ubidi_setPara()</code> and
1115 * <code>ubidi_setLine()</code> functions may modify some or all of the l evels.<br><br>
1116 * After the <code>UBiDi</code> object is reused or destroyed, the caller
1117 * must take care of the deallocation of the <code>embeddingLevels</code> array.<br><br>
1118 * <strong>Note:</strong> the <code>embeddingLevels</code> array must be
1119 * at least <code>length</code> long.
1120 * This pointer can be <code>NULL</code> if this
1121 * value is not necessary.
1122 *
1123 * @param pErrorCode must be a valid pointer to an error code value.
1124 * @stable ICU 2.0
1125 */
1126 U_STABLE void U_EXPORT2
1127 ubidi_setPara(UBiDi *pBiDi, const UChar *text, int32_t length,
1128 UBiDiLevel paraLevel, UBiDiLevel *embeddingLevels,
1129 UErrorCode *pErrorCode);
1130
1131 /**
1132 * <code>ubidi_setLine()</code> sets a <code>UBiDi</code> to
1133 * contain the reordering information, especially the resolved levels,
1134 * for all the characters in a line of text. This line of text is
1135 * specified by referring to a <code>UBiDi</code> object representing
1136 * this information for a piece of text containing one or more paragraphs,
1137 * and by specifying a range of indexes in this text.<p>
1138 * In the new line object, the indexes will range from 0 to <code>limit-start-1< /code>.<p>
1139 *
1140 * This is used after calling <code>ubidi_setPara()</code>
1141 * for a piece of text, and after line-breaking on that text.
1142 * It is not necessary if each paragraph is treated as a single line.<p>
1143 *
1144 * After line-breaking, rules (L1) and (L2) for the treatment of
1145 * trailing WS and for reordering are performed on
1146 * a <code>UBiDi</code> object that represents a line.<p>
1147 *
1148 * <strong>Important: </strong><code>pLineBiDi</code> shares data with
1149 * <code>pParaBiDi</code>.
1150 * You must destroy or reuse <code>pLineBiDi</code> before <code>pParaBiDi</code >.
1151 * In other words, you must destroy or reuse the <code>UBiDi</code> object for a line
1152 * before the object for its parent paragraph.<p>
1153 *
1154 * The text pointer that was stored in <code>pParaBiDi</code> is also copied,
1155 * and <code>start</code> is added to it so that it points to the beginning of t he
1156 * line for this object.
1157 *
1158 * @param pParaBiDi is the parent paragraph object. It must have been set
1159 * by a successful call to ubidi_setPara.
1160 *
1161 * @param start is the line's first index into the text.
1162 *
1163 * @param limit is just behind the line's last index into the text
1164 * (its last index +1).<br>
1165 * It must be <code>0<=start<limit<=</code>containing paragraph limit.
1166 * If the specified line crosses a paragraph boundary, the function
1167 * will terminate with error code U_ILLEGAL_ARGUMENT_ERROR.
1168 *
1169 * @param pLineBiDi is the object that will now represent a line of the text.
1170 *
1171 * @param pErrorCode must be a valid pointer to an error code value.
1172 *
1173 * @see ubidi_setPara
1174 * @see ubidi_getProcessedLength
1175 * @stable ICU 2.0
1176 */
1177 U_STABLE void U_EXPORT2
1178 ubidi_setLine(const UBiDi *pParaBiDi,
1179 int32_t start, int32_t limit,
1180 UBiDi *pLineBiDi,
1181 UErrorCode *pErrorCode);
1182
1183 /**
1184 * Get the directionality of the text.
1185 *
1186 * @param pBiDi is the paragraph or line <code>UBiDi</code> object.
1187 *
1188 * @return a value of <code>UBIDI_LTR</code>, <code>UBIDI_RTL</code>
1189 * or <code>UBIDI_MIXED</code>
1190 * that indicates if the entire text
1191 * represented by this object is unidirectional,
1192 * and which direction, or if it is mixed-directional.
1193 * Note - The value <code>UBIDI_NEUTRAL</code> is never returned from this meth od.
1194 *
1195 * @see UBiDiDirection
1196 * @stable ICU 2.0
1197 */
1198 U_STABLE UBiDiDirection U_EXPORT2
1199 ubidi_getDirection(const UBiDi *pBiDi);
1200
1201 /**
1202 * Gets the base direction of the text provided according
1203 * to the Unicode Bidirectional Algorithm. The base direction
1204 * is derived from the first character in the string with bidirectional
1205 * character type L, R, or AL. If the first such character has type L,
1206 * <code>UBIDI_LTR</code> is returned. If the first such character has
1207 * type R or AL, <code>UBIDI_RTL</code> is returned. If the string does
1208 * not contain any character of these types, then
1209 * <code>UBIDI_NEUTRAL</code> is returned.
1210 *
1211 * This is a lightweight function for use when only the base direction
1212 * is needed and no further bidi processing of the text is needed.
1213 *
1214 * @param text is a pointer to the text whose base
1215 * direction is needed.
1216 * Note: the text must be (at least) @c length long.
1217 *
1218 * @param length is the length of the text;
1219 * if <code>length==-1</code> then the text
1220 * must be zero-terminated.
1221 *
1222 * @return <code>UBIDI_LTR</code>, <code>UBIDI_RTL</code>,
1223 * <code>UBIDI_NEUTRAL</code>
1224 *
1225 * @see UBiDiDirection
1226 * @draft ICU 4.6
1227 */
1228 U_DRAFT UBiDiDirection U_EXPORT2
1229 ubidi_getBaseDirection(const UChar *text, int32_t length );
1230
1231 /**
1232 * Get the pointer to the text.
1233 *
1234 * @param pBiDi is the paragraph or line <code>UBiDi</code> object.
1235 *
1236 * @return The pointer to the text that the UBiDi object was created for.
1237 *
1238 * @see ubidi_setPara
1239 * @see ubidi_setLine
1240 * @stable ICU 2.0
1241 */
1242 U_STABLE const UChar * U_EXPORT2
1243 ubidi_getText(const UBiDi *pBiDi);
1244
1245 /**
1246 * Get the length of the text.
1247 *
1248 * @param pBiDi is the paragraph or line <code>UBiDi</code> object.
1249 *
1250 * @return The length of the text that the UBiDi object was created for.
1251 * @stable ICU 2.0
1252 */
1253 U_STABLE int32_t U_EXPORT2
1254 ubidi_getLength(const UBiDi *pBiDi);
1255
1256 /**
1257 * Get the paragraph level of the text.
1258 *
1259 * @param pBiDi is the paragraph or line <code>UBiDi</code> object.
1260 *
1261 * @return The paragraph level. If there are multiple paragraphs, their
1262 * level may vary if the required paraLevel is UBIDI_DEFAULT_LTR or
1263 * UBIDI_DEFAULT_RTL. In that case, the level of the first paragraph
1264 * is returned.
1265 *
1266 * @see UBiDiLevel
1267 * @see ubidi_getParagraph
1268 * @see ubidi_getParagraphByIndex
1269 * @stable ICU 2.0
1270 */
1271 U_STABLE UBiDiLevel U_EXPORT2
1272 ubidi_getParaLevel(const UBiDi *pBiDi);
1273
1274 /**
1275 * Get the number of paragraphs.
1276 *
1277 * @param pBiDi is the paragraph or line <code>UBiDi</code> object.
1278 *
1279 * @return The number of paragraphs.
1280 * @stable ICU 3.4
1281 */
1282 U_STABLE int32_t U_EXPORT2
1283 ubidi_countParagraphs(UBiDi *pBiDi);
1284
1285 /**
1286 * Get a paragraph, given a position within the text.
1287 * This function returns information about a paragraph.<br>
1288 * Note: if the paragraph index is known, it is more efficient to
1289 * retrieve the paragraph information using ubidi_getParagraphByIndex().<p>
1290 *
1291 * @param pBiDi is the paragraph or line <code>UBiDi</code> object.
1292 *
1293 * @param charIndex is the index of a character within the text, in the
1294 * range <code>[0..ubidi_getProcessedLength(pBiDi)-1]</code>.
1295 *
1296 * @param pParaStart will receive the index of the first character of the
1297 * paragraph in the text.
1298 * This pointer can be <code>NULL</code> if this
1299 * value is not necessary.
1300 *
1301 * @param pParaLimit will receive the limit of the paragraph.
1302 * The l-value that you point to here may be the
1303 * same expression (variable) as the one for
1304 * <code>charIndex</code>.
1305 * This pointer can be <code>NULL</code> if this
1306 * value is not necessary.
1307 *
1308 * @param pParaLevel will receive the level of the paragraph.
1309 * This pointer can be <code>NULL</code> if this
1310 * value is not necessary.
1311 *
1312 * @param pErrorCode must be a valid pointer to an error code value.
1313 *
1314 * @return The index of the paragraph containing the specified position.
1315 *
1316 * @see ubidi_getProcessedLength
1317 * @stable ICU 3.4
1318 */
1319 U_STABLE int32_t U_EXPORT2
1320 ubidi_getParagraph(const UBiDi *pBiDi, int32_t charIndex, int32_t *pParaStart,
1321 int32_t *pParaLimit, UBiDiLevel *pParaLevel,
1322 UErrorCode *pErrorCode);
1323
1324 /**
1325 * Get a paragraph, given the index of this paragraph.
1326 *
1327 * This function returns information about a paragraph.<p>
1328 *
1329 * @param pBiDi is the paragraph <code>UBiDi</code> object.
1330 *
1331 * @param paraIndex is the number of the paragraph, in the
1332 * range <code>[0..ubidi_countParagraphs(pBiDi)-1]</code>.
1333 *
1334 * @param pParaStart will receive the index of the first character of the
1335 * paragraph in the text.
1336 * This pointer can be <code>NULL</code> if this
1337 * value is not necessary.
1338 *
1339 * @param pParaLimit will receive the limit of the paragraph.
1340 * This pointer can be <code>NULL</code> if this
1341 * value is not necessary.
1342 *
1343 * @param pParaLevel will receive the level of the paragraph.
1344 * This pointer can be <code>NULL</code> if this
1345 * value is not necessary.
1346 *
1347 * @param pErrorCode must be a valid pointer to an error code value.
1348 *
1349 * @stable ICU 3.4
1350 */
1351 U_STABLE void U_EXPORT2
1352 ubidi_getParagraphByIndex(const UBiDi *pBiDi, int32_t paraIndex,
1353 int32_t *pParaStart, int32_t *pParaLimit,
1354 UBiDiLevel *pParaLevel, UErrorCode *pErrorCode);
1355
1356 /**
1357 * Get the level for one character.
1358 *
1359 * @param pBiDi is the paragraph or line <code>UBiDi</code> object.
1360 *
1361 * @param charIndex the index of a character. It must be in the range
1362 * [0..ubidi_getProcessedLength(pBiDi)].
1363 *
1364 * @return The level for the character at charIndex (0 if charIndex is not
1365 * in the valid range).
1366 *
1367 * @see UBiDiLevel
1368 * @see ubidi_getProcessedLength
1369 * @stable ICU 2.0
1370 */
1371 U_STABLE UBiDiLevel U_EXPORT2
1372 ubidi_getLevelAt(const UBiDi *pBiDi, int32_t charIndex);
1373
1374 /**
1375 * Get an array of levels for each character.<p>
1376 *
1377 * Note that this function may allocate memory under some
1378 * circumstances, unlike <code>ubidi_getLevelAt()</code>.
1379 *
1380 * @param pBiDi is the paragraph or line <code>UBiDi</code> object, whose
1381 * text length must be strictly positive.
1382 *
1383 * @param pErrorCode must be a valid pointer to an error code value.
1384 *
1385 * @return The levels array for the text,
1386 * or <code>NULL</code> if an error occurs.
1387 *
1388 * @see UBiDiLevel
1389 * @see ubidi_getProcessedLength
1390 * @stable ICU 2.0
1391 */
1392 U_STABLE const UBiDiLevel * U_EXPORT2
1393 ubidi_getLevels(UBiDi *pBiDi, UErrorCode *pErrorCode);
1394
1395 /**
1396 * Get a logical run.
1397 * This function returns information about a run and is used
1398 * to retrieve runs in logical order.<p>
1399 * This is especially useful for line-breaking on a paragraph.
1400 *
1401 * @param pBiDi is the paragraph or line <code>UBiDi</code> object.
1402 *
1403 * @param logicalPosition is a logical position within the source text.
1404 *
1405 * @param pLogicalLimit will receive the limit of the corresponding run.
1406 * The l-value that you point to here may be the
1407 * same expression (variable) as the one for
1408 * <code>logicalPosition</code>.
1409 * This pointer can be <code>NULL</code> if this
1410 * value is not necessary.
1411 *
1412 * @param pLevel will receive the level of the corresponding run.
1413 * This pointer can be <code>NULL</code> if this
1414 * value is not necessary.
1415 *
1416 * @see ubidi_getProcessedLength
1417 * @stable ICU 2.0
1418 */
1419 U_STABLE void U_EXPORT2
1420 ubidi_getLogicalRun(const UBiDi *pBiDi, int32_t logicalPosition,
1421 int32_t *pLogicalLimit, UBiDiLevel *pLevel);
1422
1423 /**
1424 * Get the number of runs.
1425 * This function may invoke the actual reordering on the
1426 * <code>UBiDi</code> object, after <code>ubidi_setPara()</code>
1427 * may have resolved only the levels of the text. Therefore,
1428 * <code>ubidi_countRuns()</code> may have to allocate memory,
1429 * and may fail doing so.
1430 *
1431 * @param pBiDi is the paragraph or line <code>UBiDi</code> object.
1432 *
1433 * @param pErrorCode must be a valid pointer to an error code value.
1434 *
1435 * @return The number of runs.
1436 * @stable ICU 2.0
1437 */
1438 U_STABLE int32_t U_EXPORT2
1439 ubidi_countRuns(UBiDi *pBiDi, UErrorCode *pErrorCode);
1440
1441 /**
1442 * Get one run's logical start, length, and directionality,
1443 * which can be 0 for LTR or 1 for RTL.
1444 * In an RTL run, the character at the logical start is
1445 * visually on the right of the displayed run.
1446 * The length is the number of characters in the run.<p>
1447 * <code>ubidi_countRuns()</code> should be called
1448 * before the runs are retrieved.
1449 *
1450 * @param pBiDi is the paragraph or line <code>UBiDi</code> object.
1451 *
1452 * @param runIndex is the number of the run in visual order, in the
1453 * range <code>[0..ubidi_countRuns(pBiDi)-1]</code>.
1454 *
1455 * @param pLogicalStart is the first logical character index in the text.
1456 * The pointer may be <code>NULL</code> if this index is not needed.
1457 *
1458 * @param pLength is the number of characters (at least one) in the run.
1459 * The pointer may be <code>NULL</code> if this is not needed.
1460 *
1461 * @return the directionality of the run,
1462 * <code>UBIDI_LTR==0</code> or <code>UBIDI_RTL==1</code>,
1463 * never <code>UBIDI_MIXED</code>,
1464 * never <code>UBIDI_NEUTRAL</code>.
1465 *
1466 * @see ubidi_countRuns
1467 *
1468 * Example:
1469 * <pre>
1470 * \code
1471 * int32_t i, count=ubidi_countRuns(pBiDi),
1472 * logicalStart, visualIndex=0, length;
1473 * for(i=0; i<count; ++i) {
1474 * if(UBIDI_LTR==ubidi_getVisualRun(pBiDi, i, &logicalStart, &length)) {
1475 * do { // LTR
1476 * show_char(text[logicalStart++], visualIndex++);
1477 * } while(--length>0);
1478 * } else {
1479 * logicalStart+=length; // logicalLimit
1480 * do { // RTL
1481 * show_char(text[--logicalStart], visualIndex++);
1482 * } while(--length>0);
1483 * }
1484 * }
1485 *\endcode
1486 * </pre>
1487 *
1488 * Note that in right-to-left runs, code like this places
1489 * second surrogates before first ones (which is generally a bad idea)
1490 * and combining characters before base characters.
1491 * <p>
1492 * Use of <code>ubidi_writeReordered()</code>, optionally with the
1493 * <code>#UBIDI_KEEP_BASE_COMBINING</code> option, can be considered in order
1494 * to avoid these issues.
1495 * @stable ICU 2.0
1496 */
1497 U_STABLE UBiDiDirection U_EXPORT2
1498 ubidi_getVisualRun(UBiDi *pBiDi, int32_t runIndex,
1499 int32_t *pLogicalStart, int32_t *pLength);
1500
1501 /**
1502 * Get the visual position from a logical text position.
1503 * If such a mapping is used many times on the same
1504 * <code>UBiDi</code> object, then calling
1505 * <code>ubidi_getLogicalMap()</code> is more efficient.<p>
1506 *
1507 * The value returned may be <code>#UBIDI_MAP_NOWHERE</code> if there is no
1508 * visual position because the corresponding text character is a Bidi control
1509 * removed from output by the option <code>#UBIDI_OPTION_REMOVE_CONTROLS</code>.
1510 * <p>
1511 * When the visual output is altered by using options of
1512 * <code>ubidi_writeReordered()</code> such as <code>UBIDI_INSERT_LRM_FOR_NUMERI C</code>,
1513 * <code>UBIDI_KEEP_BASE_COMBINING</code>, <code>UBIDI_OUTPUT_REVERSE</code>,
1514 * <code>UBIDI_REMOVE_BIDI_CONTROLS</code>, the visual position returned may not
1515 * be correct. It is advised to use, when possible, reordering options
1516 * such as <code>UBIDI_OPTION_INSERT_MARKS</code> and <code>UBIDI_OPTION_REMOVE_ CONTROLS</code>.
1517 * <p>
1518 * Note that in right-to-left runs, this mapping places
1519 * second surrogates before first ones (which is generally a bad idea)
1520 * and combining characters before base characters.
1521 * Use of <code>ubidi_writeReordered()</code>, optionally with the
1522 * <code>#UBIDI_KEEP_BASE_COMBINING</code> option can be considered instead
1523 * of using the mapping, in order to avoid these issues.
1524 *
1525 * @param pBiDi is the paragraph or line <code>UBiDi</code> object.
1526 *
1527 * @param logicalIndex is the index of a character in the text.
1528 *
1529 * @param pErrorCode must be a valid pointer to an error code value.
1530 *
1531 * @return The visual position of this character.
1532 *
1533 * @see ubidi_getLogicalMap
1534 * @see ubidi_getLogicalIndex
1535 * @see ubidi_getProcessedLength
1536 * @stable ICU 2.0
1537 */
1538 U_STABLE int32_t U_EXPORT2
1539 ubidi_getVisualIndex(UBiDi *pBiDi, int32_t logicalIndex, UErrorCode *pErrorCode) ;
1540
1541 /**
1542 * Get the logical text position from a visual position.
1543 * If such a mapping is used many times on the same
1544 * <code>UBiDi</code> object, then calling
1545 * <code>ubidi_getVisualMap()</code> is more efficient.<p>
1546 *
1547 * The value returned may be <code>#UBIDI_MAP_NOWHERE</code> if there is no
1548 * logical position because the corresponding text character is a Bidi mark
1549 * inserted in the output by option <code>#UBIDI_OPTION_INSERT_MARKS</code>.
1550 * <p>
1551 * This is the inverse function to <code>ubidi_getVisualIndex()</code>.
1552 * <p>
1553 * When the visual output is altered by using options of
1554 * <code>ubidi_writeReordered()</code> such as <code>UBIDI_INSERT_LRM_FOR_NUMERI C</code>,
1555 * <code>UBIDI_KEEP_BASE_COMBINING</code>, <code>UBIDI_OUTPUT_REVERSE</code>,
1556 * <code>UBIDI_REMOVE_BIDI_CONTROLS</code>, the logical position returned may no t
1557 * be correct. It is advised to use, when possible, reordering options
1558 * such as <code>UBIDI_OPTION_INSERT_MARKS</code> and <code>UBIDI_OPTION_REMOVE_ CONTROLS</code>.
1559 *
1560 * @param pBiDi is the paragraph or line <code>UBiDi</code> object.
1561 *
1562 * @param visualIndex is the visual position of a character.
1563 *
1564 * @param pErrorCode must be a valid pointer to an error code value.
1565 *
1566 * @return The index of this character in the text.
1567 *
1568 * @see ubidi_getVisualMap
1569 * @see ubidi_getVisualIndex
1570 * @see ubidi_getResultLength
1571 * @stable ICU 2.0
1572 */
1573 U_STABLE int32_t U_EXPORT2
1574 ubidi_getLogicalIndex(UBiDi *pBiDi, int32_t visualIndex, UErrorCode *pErrorCode) ;
1575
1576 /**
1577 * Get a logical-to-visual index map (array) for the characters in the UBiDi
1578 * (paragraph or line) object.
1579 * <p>
1580 * Some values in the map may be <code>#UBIDI_MAP_NOWHERE</code> if the
1581 * corresponding text characters are Bidi controls removed from the visual
1582 * output by the option <code>#UBIDI_OPTION_REMOVE_CONTROLS</code>.
1583 * <p>
1584 * When the visual output is altered by using options of
1585 * <code>ubidi_writeReordered()</code> such as <code>UBIDI_INSERT_LRM_FOR_NUMERI C</code>,
1586 * <code>UBIDI_KEEP_BASE_COMBINING</code>, <code>UBIDI_OUTPUT_REVERSE</code>,
1587 * <code>UBIDI_REMOVE_BIDI_CONTROLS</code>, the visual positions returned may no t
1588 * be correct. It is advised to use, when possible, reordering options
1589 * such as <code>UBIDI_OPTION_INSERT_MARKS</code> and <code>UBIDI_OPTION_REMOVE_ CONTROLS</code>.
1590 * <p>
1591 * Note that in right-to-left runs, this mapping places
1592 * second surrogates before first ones (which is generally a bad idea)
1593 * and combining characters before base characters.
1594 * Use of <code>ubidi_writeReordered()</code>, optionally with the
1595 * <code>#UBIDI_KEEP_BASE_COMBINING</code> option can be considered instead
1596 * of using the mapping, in order to avoid these issues.
1597 *
1598 * @param pBiDi is the paragraph or line <code>UBiDi</code> object.
1599 *
1600 * @param indexMap is a pointer to an array of <code>ubidi_getProcessedLength()< /code>
1601 * indexes which will reflect the reordering of the characters.
1602 * If option <code>#UBIDI_OPTION_INSERT_MARKS</code> is set, the number
1603 * of elements allocated in <code>indexMap</code> must be no less than
1604 * <code>ubidi_getResultLength()</code>.
1605 * The array does not need to be initialized.<br><br>
1606 * The index map will result in <code>indexMap[logicalIndex]==visualIndex </code>.
1607 *
1608 * @param pErrorCode must be a valid pointer to an error code value.
1609 *
1610 * @see ubidi_getVisualMap
1611 * @see ubidi_getVisualIndex
1612 * @see ubidi_getProcessedLength
1613 * @see ubidi_getResultLength
1614 * @stable ICU 2.0
1615 */
1616 U_STABLE void U_EXPORT2
1617 ubidi_getLogicalMap(UBiDi *pBiDi, int32_t *indexMap, UErrorCode *pErrorCode);
1618
1619 /**
1620 * Get a visual-to-logical index map (array) for the characters in the UBiDi
1621 * (paragraph or line) object.
1622 * <p>
1623 * Some values in the map may be <code>#UBIDI_MAP_NOWHERE</code> if the
1624 * corresponding text characters are Bidi marks inserted in the visual output
1625 * by the option <code>#UBIDI_OPTION_INSERT_MARKS</code>.
1626 * <p>
1627 * When the visual output is altered by using options of
1628 * <code>ubidi_writeReordered()</code> such as <code>UBIDI_INSERT_LRM_FOR_NUMERI C</code>,
1629 * <code>UBIDI_KEEP_BASE_COMBINING</code>, <code>UBIDI_OUTPUT_REVERSE</code>,
1630 * <code>UBIDI_REMOVE_BIDI_CONTROLS</code>, the logical positions returned may n ot
1631 * be correct. It is advised to use, when possible, reordering options
1632 * such as <code>UBIDI_OPTION_INSERT_MARKS</code> and <code>UBIDI_OPTION_REMOVE_ CONTROLS</code>.
1633 *
1634 * @param pBiDi is the paragraph or line <code>UBiDi</code> object.
1635 *
1636 * @param indexMap is a pointer to an array of <code>ubidi_getResultLength()</co de>
1637 * indexes which will reflect the reordering of the characters.
1638 * If option <code>#UBIDI_OPTION_REMOVE_CONTROLS</code> is set, the numbe r
1639 * of elements allocated in <code>indexMap</code> must be no less than
1640 * <code>ubidi_getProcessedLength()</code>.
1641 * The array does not need to be initialized.<br><br>
1642 * The index map will result in <code>indexMap[visualIndex]==logicalIndex </code>.
1643 *
1644 * @param pErrorCode must be a valid pointer to an error code value.
1645 *
1646 * @see ubidi_getLogicalMap
1647 * @see ubidi_getLogicalIndex
1648 * @see ubidi_getProcessedLength
1649 * @see ubidi_getResultLength
1650 * @stable ICU 2.0
1651 */
1652 U_STABLE void U_EXPORT2
1653 ubidi_getVisualMap(UBiDi *pBiDi, int32_t *indexMap, UErrorCode *pErrorCode);
1654
1655 /**
1656 * This is a convenience function that does not use a UBiDi object.
1657 * It is intended to be used for when an application has determined the levels
1658 * of objects (character sequences) and just needs to have them reordered (L2).
1659 * This is equivalent to using <code>ubidi_getLogicalMap()</code> on a
1660 * <code>UBiDi</code> object.
1661 *
1662 * @param levels is an array with <code>length</code> levels that have been dete rmined by
1663 * the application.
1664 *
1665 * @param length is the number of levels in the array, or, semantically,
1666 * the number of objects to be reordered.
1667 * It must be <code>length>0</code>.
1668 *
1669 * @param indexMap is a pointer to an array of <code>length</code>
1670 * indexes which will reflect the reordering of the characters.
1671 * The array does not need to be initialized.<p>
1672 * The index map will result in <code>indexMap[logicalIndex]==visualIndex </code>.
1673 * @stable ICU 2.0
1674 */
1675 U_STABLE void U_EXPORT2
1676 ubidi_reorderLogical(const UBiDiLevel *levels, int32_t length, int32_t *indexMap );
1677
1678 /**
1679 * This is a convenience function that does not use a UBiDi object.
1680 * It is intended to be used for when an application has determined the levels
1681 * of objects (character sequences) and just needs to have them reordered (L2).
1682 * This is equivalent to using <code>ubidi_getVisualMap()</code> on a
1683 * <code>UBiDi</code> object.
1684 *
1685 * @param levels is an array with <code>length</code> levels that have been dete rmined by
1686 * the application.
1687 *
1688 * @param length is the number of levels in the array, or, semantically,
1689 * the number of objects to be reordered.
1690 * It must be <code>length>0</code>.
1691 *
1692 * @param indexMap is a pointer to an array of <code>length</code>
1693 * indexes which will reflect the reordering of the characters.
1694 * The array does not need to be initialized.<p>
1695 * The index map will result in <code>indexMap[visualIndex]==logicalIndex </code>.
1696 * @stable ICU 2.0
1697 */
1698 U_STABLE void U_EXPORT2
1699 ubidi_reorderVisual(const UBiDiLevel *levels, int32_t length, int32_t *indexMap) ;
1700
1701 /**
1702 * Invert an index map.
1703 * The index mapping of the first map is inverted and written to
1704 * the second one.
1705 *
1706 * @param srcMap is an array with <code>length</code> elements
1707 * which defines the original mapping from a source array containing
1708 * <code>length</code> elements to a destination array.
1709 * Some elements of the source array may have no mapping in the
1710 * destination array. In that case, their value will be
1711 * the special value <code>UBIDI_MAP_NOWHERE</code>.
1712 * All elements must be >=0 or equal to <code>UBIDI_MAP_NOWHERE</code>.
1713 * Some elements may have a value >= <code>length</code>, if the
1714 * destination array has more elements than the source array.
1715 * There must be no duplicate indexes (two or more elements with the
1716 * same value except <code>UBIDI_MAP_NOWHERE</code>).
1717 *
1718 * @param destMap is an array with a number of elements equal to 1 + the highest
1719 * value in <code>srcMap</code>.
1720 * <code>destMap</code> will be filled with the inverse mapping.
1721 * If element with index i in <code>srcMap</code> has a value k different
1722 * from <code>UBIDI_MAP_NOWHERE</code>, this means that element i of
1723 * the source array maps to element k in the destination array.
1724 * The inverse map will have value i in its k-th element.
1725 * For all elements of the destination array which do not map to
1726 * an element in the source array, the corresponding element in the
1727 * inverse map will have a value equal to <code>UBIDI_MAP_NOWHERE</code>.
1728 *
1729 * @param length is the length of each array.
1730 * @see UBIDI_MAP_NOWHERE
1731 * @stable ICU 2.0
1732 */
1733 U_STABLE void U_EXPORT2
1734 ubidi_invertMap(const int32_t *srcMap, int32_t *destMap, int32_t length);
1735
1736 /** option flags for ubidi_writeReordered() */
1737
1738 /**
1739 * option bit for ubidi_writeReordered():
1740 * keep combining characters after their base characters in RTL runs
1741 *
1742 * @see ubidi_writeReordered
1743 * @stable ICU 2.0
1744 */
1745 #define UBIDI_KEEP_BASE_COMBINING 1
1746
1747 /**
1748 * option bit for ubidi_writeReordered():
1749 * replace characters with the "mirrored" property in RTL runs
1750 * by their mirror-image mappings
1751 *
1752 * @see ubidi_writeReordered
1753 * @stable ICU 2.0
1754 */
1755 #define UBIDI_DO_MIRRORING 2
1756
1757 /**
1758 * option bit for ubidi_writeReordered():
1759 * surround the run with LRMs if necessary;
1760 * this is part of the approximate "inverse Bidi" algorithm
1761 *
1762 * <p>This option does not imply corresponding adjustment of the index
1763 * mappings.</p>
1764 *
1765 * @see ubidi_setInverse
1766 * @see ubidi_writeReordered
1767 * @stable ICU 2.0
1768 */
1769 #define UBIDI_INSERT_LRM_FOR_NUMERIC 4
1770
1771 /**
1772 * option bit for ubidi_writeReordered():
1773 * remove Bidi control characters
1774 * (this does not affect #UBIDI_INSERT_LRM_FOR_NUMERIC)
1775 *
1776 * <p>This option does not imply corresponding adjustment of the index
1777 * mappings.</p>
1778 *
1779 * @see ubidi_writeReordered
1780 * @stable ICU 2.0
1781 */
1782 #define UBIDI_REMOVE_BIDI_CONTROLS 8
1783
1784 /**
1785 * option bit for ubidi_writeReordered():
1786 * write the output in reverse order
1787 *
1788 * <p>This has the same effect as calling <code>ubidi_writeReordered()</code>
1789 * first without this option, and then calling
1790 * <code>ubidi_writeReverse()</code> without mirroring.
1791 * Doing this in the same step is faster and avoids a temporary buffer.
1792 * An example for using this option is output to a character terminal that
1793 * is designed for RTL scripts and stores text in reverse order.</p>
1794 *
1795 * @see ubidi_writeReordered
1796 * @stable ICU 2.0
1797 */
1798 #define UBIDI_OUTPUT_REVERSE 16
1799
1800 /**
1801 * Get the length of the source text processed by the last call to
1802 * <code>ubidi_setPara()</code>. This length may be different from the length
1803 * of the source text if option <code>#UBIDI_OPTION_STREAMING</code>
1804 * has been set.
1805 * <br>
1806 * Note that whenever the length of the text affects the execution or the
1807 * result of a function, it is the processed length which must be considered,
1808 * except for <code>ubidi_setPara</code> (which receives unprocessed source
1809 * text) and <code>ubidi_getLength</code> (which returns the original length
1810 * of the source text).<br>
1811 * In particular, the processed length is the one to consider in the following
1812 * cases:
1813 * <ul>
1814 * <li>maximum value of the <code>limit</code> argument of
1815 * <code>ubidi_setLine</code></li>
1816 * <li>maximum value of the <code>charIndex</code> argument of
1817 * <code>ubidi_getParagraph</code></li>
1818 * <li>maximum value of the <code>charIndex</code> argument of
1819 * <code>ubidi_getLevelAt</code></li>
1820 * <li>number of elements in the array returned by <code>ubidi_getLevels</code>< /li>
1821 * <li>maximum value of the <code>logicalStart</code> argument of
1822 * <code>ubidi_getLogicalRun</code></li>
1823 * <li>maximum value of the <code>logicalIndex</code> argument of
1824 * <code>ubidi_getVisualIndex</code></li>
1825 * <li>number of elements filled in the <code>*indexMap</code> argument of
1826 * <code>ubidi_getLogicalMap</code></li>
1827 * <li>length of text processed by <code>ubidi_writeReordered</code></li>
1828 * </ul>
1829 *
1830 * @param pBiDi is the paragraph <code>UBiDi</code> object.
1831 *
1832 * @return The length of the part of the source text processed by
1833 * the last call to <code>ubidi_setPara</code>.
1834 * @see ubidi_setPara
1835 * @see UBIDI_OPTION_STREAMING
1836 * @stable ICU 3.6
1837 */
1838 U_STABLE int32_t U_EXPORT2
1839 ubidi_getProcessedLength(const UBiDi *pBiDi);
1840
1841 /**
1842 * Get the length of the reordered text resulting from the last call to
1843 * <code>ubidi_setPara()</code>. This length may be different from the length
1844 * of the source text if option <code>#UBIDI_OPTION_INSERT_MARKS</code>
1845 * or option <code>#UBIDI_OPTION_REMOVE_CONTROLS</code> has been set.
1846 * <br>
1847 * This resulting length is the one to consider in the following cases:
1848 * <ul>
1849 * <li>maximum value of the <code>visualIndex</code> argument of
1850 * <code>ubidi_getLogicalIndex</code></li>
1851 * <li>number of elements of the <code>*indexMap</code> argument of
1852 * <code>ubidi_getVisualMap</code></li>
1853 * </ul>
1854 * Note that this length stays identical to the source text length if
1855 * Bidi marks are inserted or removed using option bits of
1856 * <code>ubidi_writeReordered</code>, or if option
1857 * <code>#UBIDI_REORDER_INVERSE_NUMBERS_AS_L</code> has been set.
1858 *
1859 * @param pBiDi is the paragraph <code>UBiDi</code> object.
1860 *
1861 * @return The length of the reordered text resulting from
1862 * the last call to <code>ubidi_setPara</code>.
1863 * @see ubidi_setPara
1864 * @see UBIDI_OPTION_INSERT_MARKS
1865 * @see UBIDI_OPTION_REMOVE_CONTROLS
1866 * @stable ICU 3.6
1867 */
1868 U_STABLE int32_t U_EXPORT2
1869 ubidi_getResultLength(const UBiDi *pBiDi);
1870
1871 U_CDECL_BEGIN
1872 /**
1873 * value returned by <code>UBiDiClassCallback</code> callbacks when
1874 * there is no need to override the standard Bidi class for a given code point.
1875 * @see UBiDiClassCallback
1876 * @stable ICU 3.6
1877 */
1878 #define U_BIDI_CLASS_DEFAULT U_CHAR_DIRECTION_COUNT
1879
1880 /**
1881 * Callback type declaration for overriding default Bidi class values with
1882 * custom ones.
1883 * <p>Usually, the function pointer will be propagated to a <code>UBiDi</code>
1884 * object by calling the <code>ubidi_setClassCallback()</code> function;
1885 * then the callback will be invoked by the UBA implementation any time the
1886 * class of a character is to be determined.</p>
1887 *
1888 * @param context is a pointer to the callback private data.
1889 *
1890 * @param c is the code point to get a Bidi class for.
1891 *
1892 * @return The directional property / Bidi class for the given code point
1893 * <code>c</code> if the default class has been overridden, or
1894 * <code>#U_BIDI_CLASS_DEFAULT</code> if the standard Bidi class value
1895 * for <code>c</code> is to be used.
1896 * @see ubidi_setClassCallback
1897 * @see ubidi_getClassCallback
1898 * @stable ICU 3.6
1899 */
1900 typedef UCharDirection U_CALLCONV
1901 UBiDiClassCallback(const void *context, UChar32 c);
1902
1903 U_CDECL_END
1904
1905 /**
1906 * Retrieve the Bidi class for a given code point.
1907 * <p>If a <code>#UBiDiClassCallback</code> callback is defined and returns a
1908 * value other than <code>#U_BIDI_CLASS_DEFAULT</code>, that value is used;
1909 * otherwise the default class determination mechanism is invoked.</p>
1910 *
1911 * @param pBiDi is the paragraph <code>UBiDi</code> object.
1912 *
1913 * @param c is the code point whose Bidi class must be retrieved.
1914 *
1915 * @return The Bidi class for character <code>c</code> based
1916 * on the given <code>pBiDi</code> instance.
1917 * @see UBiDiClassCallback
1918 * @stable ICU 3.6
1919 */
1920 U_STABLE UCharDirection U_EXPORT2
1921 ubidi_getCustomizedClass(UBiDi *pBiDi, UChar32 c);
1922
1923 /**
1924 * Set the callback function and callback data used by the UBA
1925 * implementation for Bidi class determination.
1926 * <p>This may be useful for assigning Bidi classes to PUA characters, or
1927 * for special application needs. For instance, an application may want to
1928 * handle all spaces like L or R characters (according to the base direction)
1929 * when creating the visual ordering of logical lines which are part of a report
1930 * organized in columns: there should not be interaction between adjacent
1931 * cells.<p>
1932 *
1933 * @param pBiDi is the paragraph <code>UBiDi</code> object.
1934 *
1935 * @param newFn is the new callback function pointer.
1936 *
1937 * @param newContext is the new callback context pointer. This can be NULL.
1938 *
1939 * @param oldFn fillin: Returns the old callback function pointer. This can be
1940 * NULL.
1941 *
1942 * @param oldContext fillin: Returns the old callback's context. This can be
1943 * NULL.
1944 *
1945 * @param pErrorCode must be a valid pointer to an error code value.
1946 *
1947 * @see ubidi_getClassCallback
1948 * @stable ICU 3.6
1949 */
1950 U_STABLE void U_EXPORT2
1951 ubidi_setClassCallback(UBiDi *pBiDi, UBiDiClassCallback *newFn,
1952 const void *newContext, UBiDiClassCallback **oldFn,
1953 const void **oldContext, UErrorCode *pErrorCode);
1954
1955 /**
1956 * Get the current callback function used for Bidi class determination.
1957 *
1958 * @param pBiDi is the paragraph <code>UBiDi</code> object.
1959 *
1960 * @param fn fillin: Returns the callback function pointer.
1961 *
1962 * @param context fillin: Returns the callback's private context.
1963 *
1964 * @see ubidi_setClassCallback
1965 * @stable ICU 3.6
1966 */
1967 U_STABLE void U_EXPORT2
1968 ubidi_getClassCallback(UBiDi *pBiDi, UBiDiClassCallback **fn, const void **conte xt);
1969
1970 /**
1971 * Take a <code>UBiDi</code> object containing the reordering
1972 * information for a piece of text (one or more paragraphs) set by
1973 * <code>ubidi_setPara()</code> or for a line of text set by
1974 * <code>ubidi_setLine()</code> and write a reordered string to the
1975 * destination buffer.
1976 *
1977 * This function preserves the integrity of characters with multiple
1978 * code units and (optionally) combining characters.
1979 * Characters in RTL runs can be replaced by mirror-image characters
1980 * in the destination buffer. Note that "real" mirroring has
1981 * to be done in a rendering engine by glyph selection
1982 * and that for many "mirrored" characters there are no
1983 * Unicode characters as mirror-image equivalents.
1984 * There are also options to insert or remove Bidi control
1985 * characters; see the description of the <code>destSize</code>
1986 * and <code>options</code> parameters and of the option bit flags.
1987 *
1988 * @param pBiDi A pointer to a <code>UBiDi</code> object that
1989 * is set by <code>ubidi_setPara()</code> or
1990 * <code>ubidi_setLine()</code> and contains the reordering
1991 * information for the text that it was defined for,
1992 * as well as a pointer to that text.<br><br>
1993 * The text was aliased (only the pointer was stored
1994 * without copying the contents) and must not have been modified
1995 * since the <code>ubidi_setPara()</code> call.
1996 *
1997 * @param dest A pointer to where the reordered text is to be copied.
1998 * The source text and <code>dest[destSize]</code>
1999 * must not overlap.
2000 *
2001 * @param destSize The size of the <code>dest</code> buffer,
2002 * in number of UChars.
2003 * If the <code>UBIDI_INSERT_LRM_FOR_NUMERIC</code>
2004 * option is set, then the destination length could be
2005 * as large as
2006 * <code>ubidi_getLength(pBiDi)+2*ubidi_countRuns(pBiDi)</code>.
2007 * If the <code>UBIDI_REMOVE_BIDI_CONTROLS</code> option
2008 * is set, then the destination length may be less than
2009 * <code>ubidi_getLength(pBiDi)</code>.
2010 * If none of these options is set, then the destination length
2011 * will be exactly <code>ubidi_getProcessedLength(pBiDi)</code>.
2012 *
2013 * @param options A bit set of options for the reordering that control
2014 * how the reordered text is written.
2015 * The options include mirroring the characters on a code
2016 * point basis and inserting LRM characters, which is used
2017 * especially for transforming visually stored text
2018 * to logically stored text (although this is still an
2019 * imperfect implementation of an "inverse Bidi" algorithm
2020 * because it uses the "forward Bidi" algorithm at its core).
2021 * The available options are:
2022 * <code>#UBIDI_DO_MIRRORING</code>,
2023 * <code>#UBIDI_INSERT_LRM_FOR_NUMERIC</code>,
2024 * <code>#UBIDI_KEEP_BASE_COMBINING</code>,
2025 * <code>#UBIDI_OUTPUT_REVERSE</code>,
2026 * <code>#UBIDI_REMOVE_BIDI_CONTROLS</code>
2027 *
2028 * @param pErrorCode must be a valid pointer to an error code value.
2029 *
2030 * @return The length of the output string.
2031 *
2032 * @see ubidi_getProcessedLength
2033 * @stable ICU 2.0
2034 */
2035 U_STABLE int32_t U_EXPORT2
2036 ubidi_writeReordered(UBiDi *pBiDi,
2037 UChar *dest, int32_t destSize,
2038 uint16_t options,
2039 UErrorCode *pErrorCode);
2040
2041 /**
2042 * Reverse a Right-To-Left run of Unicode text.
2043 *
2044 * This function preserves the integrity of characters with multiple
2045 * code units and (optionally) combining characters.
2046 * Characters can be replaced by mirror-image characters
2047 * in the destination buffer. Note that "real" mirroring has
2048 * to be done in a rendering engine by glyph selection
2049 * and that for many "mirrored" characters there are no
2050 * Unicode characters as mirror-image equivalents.
2051 * There are also options to insert or remove Bidi control
2052 * characters.
2053 *
2054 * This function is the implementation for reversing RTL runs as part
2055 * of <code>ubidi_writeReordered()</code>. For detailed descriptions
2056 * of the parameters, see there.
2057 * Since no Bidi controls are inserted here, the output string length
2058 * will never exceed <code>srcLength</code>.
2059 *
2060 * @see ubidi_writeReordered
2061 *
2062 * @param src A pointer to the RTL run text.
2063 *
2064 * @param srcLength The length of the RTL run.
2065 *
2066 * @param dest A pointer to where the reordered text is to be copied.
2067 * <code>src[srcLength]</code> and <code>dest[destSize]</code>
2068 * must not overlap.
2069 *
2070 * @param destSize The size of the <code>dest</code> buffer,
2071 * in number of UChars.
2072 * If the <code>UBIDI_REMOVE_BIDI_CONTROLS</code> option
2073 * is set, then the destination length may be less than
2074 * <code>srcLength</code>.
2075 * If this option is not set, then the destination length
2076 * will be exactly <code>srcLength</code>.
2077 *
2078 * @param options A bit set of options for the reordering that control
2079 * how the reordered text is written.
2080 * See the <code>options</code> parameter in <code>ubidi_writeReo rdered()</code>.
2081 *
2082 * @param pErrorCode must be a valid pointer to an error code value.
2083 *
2084 * @return The length of the output string.
2085 * @stable ICU 2.0
2086 */
2087 U_STABLE int32_t U_EXPORT2
2088 ubidi_writeReverse(const UChar *src, int32_t srcLength,
2089 UChar *dest, int32_t destSize,
2090 uint16_t options,
2091 UErrorCode *pErrorCode);
2092
2093 /*#define BIDI_SAMPLE_CODE*/
2094 /*@}*/
2095
2096 #endif
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