1 /*
2 * Copyright (c) 2009, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25 /*
26 *******************************************************************************
27 * (C) Copyright IBM Corp. and others, 1996-2009 - All Rights Reserved *
28 * *
29 * The original version of this source code and documentation is copyrighted *
30 * and owned by IBM, These materials are provided under terms of a License *
31 * Agreement between IBM and Sun. This technology is protected by multiple *
32 * US and International patents. This notice and attribution to IBM may not *
33 * to removed. *
34 *******************************************************************************
35 */
36 /* Written by Simon Montagu, Matitiahu Allouche
37 * (ported from C code written by Markus W. Scherer)
38 */
39
40 package sun.text.bidi;
41
42 import java.text.Bidi;
43 import java.util.Arrays;
44
45 public final class BidiLine {
46
47 /*
48 * General remarks about the functions in this file:
49 *
50 * These functions deal with the aspects of potentially mixed-directional
51 * text in a single paragraph or in a line of a single paragraph
52 * which has already been processed according to
53 * the Unicode 3.0 Bidi algorithm as defined in
54 * http://www.unicode.org/unicode/reports/tr9/ , version 13,
55 * also described in The Unicode Standard, Version 4.0.1 .
56 *
57 * This means that there is a Bidi object with a levels
58 * and a dirProps array.
59 * paraLevel and direction are also set.
60 * Only if the length of the text is zero, then levels==dirProps==NULL.
61 *
62 * The overall directionality of the paragraph
63 * or line is used to bypass the reordering steps if possible.
64 * Even purely RTL text does not need reordering there because
65 * the getLogical/VisualIndex() methods can compute the
66 * index on the fly in such a case.
67 *
68 * The implementation of the access to same-level-runs and of the reordering
69 * do attempt to provide better performance and less memory usage compared to
70 * a direct implementation of especially rule (L2) with an array of
71 * one (32-bit) integer per text character.
72 *
73 * Here, the levels array is scanned as soon as necessary, and a vector of
74 * same-level-runs is created. Reordering then is done on this vector.
75 * For each run of text positions that were resolved to the same level,
76 * only 8 bytes are stored: the first text position of the run and the visual
77 * position behind the run after reordering.
78 * One sign bit is used to hold the directionality of the run.
79 * This is inefficient if there are many very short runs. If the average run
80 * length is <2, then this uses more memory.
81 *
82 * In a further attempt to save memory, the levels array is never changed
83 * after all the resolution rules (Xn, Wn, Nn, In).
84 * Many methods have to consider the field trailingWSStart:
85 * if it is less than length, then there is an implicit trailing run
86 * at the paraLevel,
87 * which is not reflected in the levels array.
88 * This allows a line Bidi object to use the same levels array as
89 * its paragraph parent object.
90 *
91 * When a Bidi object is created for a line of a paragraph, then the
92 * paragraph's levels and dirProps arrays are reused by way of setting
93 * a pointer into them, not by copying. This again saves memory and forbids to
94 * change the now shared levels for (L1).
95 */
96
97 /* handle trailing WS (L1) -------------------------------------------------- */
98
99 /*
100 * setTrailingWSStart() sets the start index for a trailing
101 * run of WS in the line. This is necessary because we do not modify
102 * the paragraph's levels array that we just point into.
103 * Using trailingWSStart is another form of performing (L1).
104 *
105 * To make subsequent operations easier, we also include the run
106 * before the WS if it is at the paraLevel - we merge the two here.
107 *
108 * This method is called only from setLine(), so paraLevel is
109 * set correctly for the line even when contextual multiple paragraphs.
110 */
111
112 static void setTrailingWSStart(BidiBase bidiBase)
113 {
114 byte[] dirProps = bidiBase.dirProps;
115 byte[] levels = bidiBase.levels;
116 int start = bidiBase.length;
117 byte paraLevel = bidiBase.paraLevel;
118
119 /* If the line is terminated by a block separator, all preceding WS etc...
120 are already set to paragraph level.
121 Setting trailingWSStart to pBidi->length will avoid changing the
122 level of B chars from 0 to paraLevel in getLevels when
123 orderParagraphsLTR==TRUE
124 */
125 if (BidiBase.NoContextRTL(dirProps[start - 1]) == BidiBase.B) {
126 bidiBase.trailingWSStart = start; /* currently == bidiBase.length */
127 return;
128 }
129 /* go backwards across all WS, BN, explicit codes */
130 while (start > 0 &&
131 (BidiBase.DirPropFlagNC(dirProps[start - 1]) & BidiBase.MASK_WS) != 0) {
132 --start;
133 }
134
135 /* if the WS run can be merged with the previous run then do so here */
136 while (start > 0 && levels[start - 1] == paraLevel) {
137 --start;
138 }
139
140 bidiBase.trailingWSStart=start;
141 }
142
143 public static Bidi setLine(Bidi bidi, BidiBase paraBidi,
144 Bidi newBidi, BidiBase newBidiBase,
145 int start, int limit) {
146 int length;
147
148 BidiBase lineBidi = newBidiBase;
149
150 /* set the values in lineBidi from its paraBidi parent */
151 /* class members are already initialized to 0 */
152 // lineBidi.paraBidi = null; /* mark unfinished setLine */
153 // lineBidi.flags = 0;
154 // lineBidi.controlCount = 0;
155
156 length = lineBidi.length = lineBidi.originalLength =
157 lineBidi.resultLength = limit - start;
158
159 lineBidi.text = new char[length];
160 System.arraycopy(paraBidi.text, start, lineBidi.text, 0, length);
161 lineBidi.paraLevel = paraBidi.GetParaLevelAt(start);
162 lineBidi.paraCount = paraBidi.paraCount;
163 lineBidi.runs = new BidiRun[0];
164 if (paraBidi.controlCount > 0) {
165 int j;
166 for (j = start; j < limit; j++) {
167 if (BidiBase.IsBidiControlChar(paraBidi.text[j])) {
168 lineBidi.controlCount++;
169 }
170 }
171 lineBidi.resultLength -= lineBidi.controlCount;
172 }
173 /* copy proper subset of DirProps */
174 lineBidi.getDirPropsMemory(length);
175 lineBidi.dirProps = lineBidi.dirPropsMemory;
176 System.arraycopy(paraBidi.dirProps, start, lineBidi.dirProps, 0,
177 length);
178 /* copy proper subset of Levels */
179 lineBidi.getLevelsMemory(length);
180 lineBidi.levels = lineBidi.levelsMemory;
181 System.arraycopy(paraBidi.levels, start, lineBidi.levels, 0,
182 length);
183 lineBidi.runCount = -1;
184
185 if (paraBidi.direction != BidiBase.MIXED) {
186 /* the parent is already trivial */
187 lineBidi.direction = paraBidi.direction;
188
189 /*
190 * The parent's levels are all either
191 * implicitly or explicitly ==paraLevel;
192 * do the same here.
193 */
194 if (paraBidi.trailingWSStart <= start) {
195 lineBidi.trailingWSStart = 0;
196 } else if (paraBidi.trailingWSStart < limit) {
197 lineBidi.trailingWSStart = paraBidi.trailingWSStart - start;
198 } else {
199 lineBidi.trailingWSStart = length;
200 }
201 } else {
202 byte[] levels = lineBidi.levels;
203 int i, trailingWSStart;
204 byte level;
205
206 setTrailingWSStart(lineBidi);
207 trailingWSStart = lineBidi.trailingWSStart;
208
209 /* recalculate lineBidi.direction */
210 if (trailingWSStart == 0) {
211 /* all levels are at paraLevel */
212 lineBidi.direction = (byte)(lineBidi.paraLevel & 1);
213 } else {
214 /* get the level of the first character */
215 level = (byte)(levels[0] & 1);
216
217 /* if there is anything of a different level, then the line
218 is mixed */
219 if (trailingWSStart < length &&
220 (lineBidi.paraLevel & 1) != level) {
221 /* the trailing WS is at paraLevel, which differs from
222 levels[0] */
223 lineBidi.direction = BidiBase.MIXED;
224 } else {
225 /* see if levels[1..trailingWSStart-1] have the same
226 direction as levels[0] and paraLevel */
227 for (i = 1; ; i++) {
228 if (i == trailingWSStart) {
229 /* the direction values match those in level */
230 lineBidi.direction = level;
231 break;
232 } else if ((levels[i] & 1) != level) {
233 lineBidi.direction = BidiBase.MIXED;
234 break;
235 }
236 }
237 }
238 }
239
240 switch(lineBidi.direction) {
241 case Bidi.DIRECTION_LEFT_TO_RIGHT:
242 /* make sure paraLevel is even */
243 lineBidi.paraLevel = (byte)
244 ((lineBidi.paraLevel + 1) & ~1);
245
246 /* all levels are implicitly at paraLevel (important for
247 getLevels()) */
248 lineBidi.trailingWSStart = 0;
249 break;
250 case Bidi.DIRECTION_RIGHT_TO_LEFT:
251 /* make sure paraLevel is odd */
252 lineBidi.paraLevel |= 1;
253
254 /* all levels are implicitly at paraLevel (important for
255 getLevels()) */
256 lineBidi.trailingWSStart = 0;
257 break;
258 default:
259 break;
260 }
261 }
262
263 newBidiBase.paraBidi = paraBidi; /* mark successful setLine */
264 return newBidi;
265 }
266
267 static byte getLevelAt(BidiBase bidiBase, int charIndex)
268 {
269 /* return paraLevel if in the trailing WS run, otherwise the real level */
270 if (bidiBase.direction != BidiBase.MIXED || charIndex >= bidiBase.trailingWSStart) {
271 return bidiBase.GetParaLevelAt(charIndex);
272 } else {
273 return bidiBase.levels[charIndex];
274 }
275 }
276
277 static byte[] getLevels(BidiBase bidiBase)
278 {
279 int start = bidiBase.trailingWSStart;
280 int length = bidiBase.length;
281
282 if (start != length) {
283 /* the current levels array does not reflect the WS run */
284 /*
285 * After the previous if(), we know that the levels array
286 * has an implicit trailing WS run and therefore does not fully
287 * reflect itself all the levels.
288 * This must be a Bidi object for a line, and
289 * we need to create a new levels array.
290 */
291 /* bidiBase.paraLevel is ok even if contextual multiple paragraphs,
292 since bidiBase is a line object */
293 Arrays.fill(bidiBase.levels, start, length, bidiBase.paraLevel);
294
295 /* this new levels array is set for the line and reflects the WS run */
296 bidiBase.trailingWSStart = length;
297 }
298 if (length < bidiBase.levels.length) {
299 byte[] levels = new byte[length];
300 System.arraycopy(bidiBase.levels, 0, levels, 0, length);
301 return levels;
302 }
303 return bidiBase.levels;
304 }
305
306 static BidiRun getLogicalRun(BidiBase bidiBase, int logicalPosition)
307 {
308 /* this is done based on runs rather than on levels since levels have
309 a special interpretation when REORDER_RUNS_ONLY
310 */
311 BidiRun newRun = new BidiRun(), iRun;
312 getRuns(bidiBase);
313 int runCount = bidiBase.runCount;
314 int visualStart = 0, logicalLimit = 0;
315 iRun = bidiBase.runs[0];
316
317 for (int i = 0; i < runCount; i++) {
318 iRun = bidiBase.runs[i];
319 logicalLimit = iRun.start + iRun.limit - visualStart;
320 if ((logicalPosition >= iRun.start) &&
321 (logicalPosition < logicalLimit)) {
322 break;
323 }
324 visualStart = iRun.limit;
325 }
326 newRun.start = iRun.start;
327 newRun.limit = logicalLimit;
328 newRun.level = iRun.level;
329 return newRun;
330 }
331
332 /* in trivial cases there is only one trivial run; called by getRuns() */
333 private static void getSingleRun(BidiBase bidiBase, byte level) {
334 /* simple, single-run case */
335 bidiBase.runs = bidiBase.simpleRuns;
336 bidiBase.runCount = 1;
337
338 /* fill and reorder the single run */
339 bidiBase.runs[0] = new BidiRun(0, bidiBase.length, level);
340 }
341
342 /* reorder the runs array (L2) ---------------------------------------------- */
343
344 /*
345 * Reorder the same-level runs in the runs array.
346 * Here, runCount>1 and maxLevel>=minLevel>=paraLevel.
347 * All the visualStart fields=logical start before reordering.
348 * The "odd" bits are not set yet.
349 *
350 * Reordering with this data structure lends itself to some handy shortcuts:
351 *
352 * Since each run is moved but not modified, and since at the initial maxLevel
353 * each sequence of same-level runs consists of only one run each, we
354 * don't need to do anything there and can predecrement maxLevel.
355 * In many simple cases, the reordering is thus done entirely in the
356 * index mapping.
357 * Also, reordering occurs only down to the lowest odd level that occurs,
358 * which is minLevel|1. However, if the lowest level itself is odd, then
359 * in the last reordering the sequence of the runs at this level or higher
360 * will be all runs, and we don't need the elaborate loop to search for them.
361 * This is covered by ++minLevel instead of minLevel|=1 followed
362 * by an extra reorder-all after the reorder-some loop.
363 * About a trailing WS run:
364 * Such a run would need special treatment because its level is not
365 * reflected in levels[] if this is not a paragraph object.
366 * Instead, all characters from trailingWSStart on are implicitly at
367 * paraLevel.
368 * However, for all maxLevel>paraLevel, this run will never be reordered
369 * and does not need to be taken into account. maxLevel==paraLevel is only reordered
370 * if minLevel==paraLevel is odd, which is done in the extra segment.
371 * This means that for the main reordering loop we don't need to consider
372 * this run and can --runCount. If it is later part of the all-runs
373 * reordering, then runCount is adjusted accordingly.
374 */
375 private static void reorderLine(BidiBase bidiBase, byte minLevel, byte maxLevel) {
376
377 /* nothing to do? */
378 if (maxLevel<=(minLevel|1)) {
379 return;
380 }
381
382 BidiRun[] runs;
383 BidiRun tempRun;
384 byte[] levels;
385 int firstRun, endRun, limitRun, runCount;
386
387 /*
388 * Reorder only down to the lowest odd level
389 * and reorder at an odd minLevel in a separate, simpler loop.
390 * See comments above for why minLevel is always incremented.
391 */
392 ++minLevel;
393
394 runs = bidiBase.runs;
395 levels = bidiBase.levels;
396 runCount = bidiBase.runCount;
397
398 /* do not include the WS run at paraLevel<=old minLevel except in the simple loop */
399 if (bidiBase.trailingWSStart < bidiBase.length) {
400 --runCount;
401 }
402
403 while (--maxLevel >= minLevel) {
404 firstRun = 0;
405
406 /* loop for all sequences of runs */
407 for ( ; ; ) {
408 /* look for a sequence of runs that are all at >=maxLevel */
409 /* look for the first run of such a sequence */
410 while (firstRun < runCount && levels[runs[firstRun].start] < maxLevel) {
411 ++firstRun;
412 }
413 if (firstRun >= runCount) {
414 break; /* no more such runs */
415 }
416
417 /* look for the limit run of such a sequence (the run behind it) */
418 for (limitRun = firstRun; ++limitRun < runCount &&
419 levels[runs[limitRun].start]>=maxLevel; ) {}
420
421 /* Swap the entire sequence of runs from firstRun to limitRun-1. */
422 endRun = limitRun - 1;
423 while (firstRun < endRun) {
424 tempRun = runs[firstRun];
425 runs[firstRun] = runs[endRun];
426 runs[endRun] = tempRun;
427 ++firstRun;
428 --endRun;
429 }
430
431 if (limitRun == runCount) {
432 break; /* no more such runs */
433 } else {
434 firstRun = limitRun + 1;
435 }
436 }
437 }
438
439 /* now do maxLevel==old minLevel (==odd!), see above */
440 if ((minLevel & 1) == 0) {
441 firstRun = 0;
442
443 /* include the trailing WS run in this complete reordering */
444 if (bidiBase.trailingWSStart == bidiBase.length) {
445 --runCount;
446 }
447
448 /* Swap the entire sequence of all runs. (endRun==runCount) */
449 while (firstRun < runCount) {
450 tempRun = runs[firstRun];
451 runs[firstRun] = runs[runCount];
452 runs[runCount] = tempRun;
453 ++firstRun;
454 --runCount;
455 }
456 }
457 }
458
459 /* compute the runs array --------------------------------------------------- */
460
461 static int getRunFromLogicalIndex(BidiBase bidiBase, int logicalIndex) {
462 BidiRun[] runs = bidiBase.runs;
463 int runCount = bidiBase.runCount, visualStart = 0, i, length, logicalStart;
464
465 for (i = 0; i < runCount; i++) {
466 length = runs[i].limit - visualStart;
467 logicalStart = runs[i].start;
468 if ((logicalIndex >= logicalStart) && (logicalIndex < (logicalStart+length))) {
469 return i;
470 }
471 visualStart += length;
472 }
473 /* we should never get here */
474 throw new IllegalStateException("Internal ICU error in getRunFromLogicalIndex");
475 }
476
477 /*
478 * Compute the runs array from the levels array.
479 * After getRuns() returns true, runCount is guaranteed to be >0
480 * and the runs are reordered.
481 * Odd-level runs have visualStart on their visual right edge and
482 * they progress visually to the left.
483 * If option OPTION_INSERT_MARKS is set, insertRemove will contain the
484 * sum of appropriate LRM/RLM_BEFORE/AFTER flags.
485 * If option OPTION_REMOVE_CONTROLS is set, insertRemove will contain the
486 * negative number of BiDi control characters within this run.
487 */
488 static void getRuns(BidiBase bidiBase) {
489 /*
490 * This method returns immediately if the runs are already set. This
491 * includes the case of length==0 (handled in setPara)..
492 */
493 if (bidiBase.runCount >= 0) {
494 return;
495 }
496 if (bidiBase.direction != BidiBase.MIXED) {
497 /* simple, single-run case - this covers length==0 */
498 /* bidiBase.paraLevel is ok even for contextual multiple paragraphs */
499 getSingleRun(bidiBase, bidiBase.paraLevel);
500 } else /* BidiBase.MIXED, length>0 */ {
501 /* mixed directionality */
502 int length = bidiBase.length, limit;
503 byte[] levels = bidiBase.levels;
504 int i, runCount;
505 byte level = BidiBase.INTERNAL_LEVEL_DEFAULT_LTR; /* initialize with no valid level */
506 /*
507 * If there are WS characters at the end of the line
508 * and the run preceding them has a level different from
509 * paraLevel, then they will form their own run at paraLevel (L1).
510 * Count them separately.
511 * We need some special treatment for this in order to not
512 * modify the levels array which a line Bidi object shares
513 * with its paragraph parent and its other line siblings.
514 * In other words, for the trailing WS, it may be
515 * levels[]!=paraLevel but we have to treat it like it were so.
516 */
517 limit = bidiBase.trailingWSStart;
518 /* count the runs, there is at least one non-WS run, and limit>0 */
519 runCount = 0;
520 for (i = 0; i < limit; ++i) {
521 /* increment runCount at the start of each run */
522 if (levels[i] != level) {
523 ++runCount;
524 level = levels[i];
525 }
526 }
527
528 /*
529 * We don't need to see if the last run can be merged with a trailing
530 * WS run because setTrailingWSStart() would have done that.
531 */
532 if (runCount == 1 && limit == length) {
533 /* There is only one non-WS run and no trailing WS-run. */
534 getSingleRun(bidiBase, levels[0]);
535 } else /* runCount>1 || limit<length */ {
536 /* allocate and set the runs */
537 BidiRun[] runs;
538 int runIndex, start;
539 byte minLevel = BidiBase.MAX_EXPLICIT_LEVEL + 1;
540 byte maxLevel=0;
541
542 /* now, count a (non-mergeable) WS run */
543 if (limit < length) {
544 ++runCount;
545 }
546
547 /* runCount > 1 */
548 bidiBase.getRunsMemory(runCount);
549 runs = bidiBase.runsMemory;
550
551 /* set the runs */
552 /* FOOD FOR THOUGHT: this could be optimized, e.g.:
553 * 464->444, 484->444, 575->555, 595->555
554 * However, that would take longer. Check also how it would
555 * interact with BiDi control removal and inserting Marks.
556 */
557 runIndex = 0;
558
559 /* search for the run limits and initialize visualLimit values with the run lengths */
560 i = 0;
561 do {
562 /* prepare this run */
563 start = i;
564 level = levels[i];
565 if (level < minLevel) {
566 minLevel = level;
567 }
568 if (level > maxLevel) {
569 maxLevel = level;
570 }
571
572 /* look for the run limit */
573 while (++i < limit && levels[i] == level) {}
574
575 /* i is another run limit */
576 runs[runIndex] = new BidiRun(start, i - start, level);
577 ++runIndex;
578 } while (i < limit);
579
580 if (limit < length) {
581 /* there is a separate WS run */
582 runs[runIndex] = new BidiRun(limit, length - limit, bidiBase.paraLevel);
583 /* For the trailing WS run, bidiBase.paraLevel is ok even
584 if contextual multiple paragraphs. */
585 if (bidiBase.paraLevel < minLevel) {
586 minLevel = bidiBase.paraLevel;
587 }
588 }
589
590 /* set the object fields */
591 bidiBase.runs = runs;
592 bidiBase.runCount = runCount;
593
594 reorderLine(bidiBase, minLevel, maxLevel);
595
596 /* now add the direction flags and adjust the visualLimit's to be just that */
597 /* this loop will also handle the trailing WS run */
598 limit = 0;
599 for (i = 0; i < runCount; ++i) {
600 runs[i].level = levels[runs[i].start];
601 limit = (runs[i].limit += limit);
602 }
603
604 /* Set the embedding level for the trailing WS run. */
605 /* For a RTL paragraph, it will be the *first* run in visual order. */
606 /* For the trailing WS run, bidiBase.paraLevel is ok even if
607 contextual multiple paragraphs. */
608 if (runIndex < runCount) {
609 int trailingRun = ((bidiBase.paraLevel & 1) != 0)? 0 : runIndex;
610 runs[trailingRun].level = bidiBase.paraLevel;
611 }
612 }
613 }
614
615 /* handle insert LRM/RLM BEFORE/AFTER run */
616 if (bidiBase.insertPoints.size > 0) {
617 BidiBase.Point point;
618 int runIndex, ip;
619 for (ip = 0; ip < bidiBase.insertPoints.size; ip++) {
620 point = bidiBase.insertPoints.points[ip];
621 runIndex = getRunFromLogicalIndex(bidiBase, point.pos);
622 bidiBase.runs[runIndex].insertRemove |= point.flag;
623 }
624 }
625
626 /* handle remove BiDi control characters */
627 if (bidiBase.controlCount > 0) {
628 int runIndex, ic;
629 char c;
630 for (ic = 0; ic < bidiBase.length; ic++) {
631 c = bidiBase.text[ic];
632 if (BidiBase.IsBidiControlChar(c)) {
633 runIndex = getRunFromLogicalIndex(bidiBase, ic);
634 bidiBase.runs[runIndex].insertRemove--;
635 }
636 }
637 }
638 }
639
640 static int[] prepareReorder(byte[] levels, byte[] pMinLevel, byte[] pMaxLevel)
641 {
642 int start;
643 byte level, minLevel, maxLevel;
644
645 if (levels == null || levels.length <= 0) {
646 return null;
647 }
648
649 /* determine minLevel and maxLevel */
650 minLevel = BidiBase.MAX_EXPLICIT_LEVEL + 1;
651 maxLevel = 0;
652 for (start = levels.length; start>0; ) {
653 level = levels[--start];
654 if (level > BidiBase.MAX_EXPLICIT_LEVEL + 1) {
655 return null;
656 }
657 if (level < minLevel) {
658 minLevel = level;
659 }
660 if (level > maxLevel) {
661 maxLevel = level;
662 }
663 }
664 pMinLevel[0] = minLevel;
665 pMaxLevel[0] = maxLevel;
666
667 /* initialize the index map */
668 int[] indexMap = new int[levels.length];
669 for (start = levels.length; start > 0; ) {
670 --start;
671 indexMap[start] = start;
672 }
673
674 return indexMap;
675 }
676
677 static int[] reorderVisual(byte[] levels)
678 {
679 byte[] aMinLevel = new byte[1];
680 byte[] aMaxLevel = new byte[1];
681 int start, end, limit, temp;
682 byte minLevel, maxLevel;
683
684 int[] indexMap = prepareReorder(levels, aMinLevel, aMaxLevel);
685 if (indexMap == null) {
686 return null;
687 }
688
689 minLevel = aMinLevel[0];
690 maxLevel = aMaxLevel[0];
691
692 /* nothing to do? */
693 if (minLevel == maxLevel && (minLevel & 1) == 0) {
694 return indexMap;
695 }
696
697 /* reorder only down to the lowest odd level */
698 minLevel |= 1;
699
700 /* loop maxLevel..minLevel */
701 do {
702 start = 0;
703
704 /* loop for all sequences of levels to reorder at the current maxLevel */
705 for ( ; ; ) {
706 /* look for a sequence of levels that are all at >=maxLevel */
707 /* look for the first index of such a sequence */
708 while (start < levels.length && levels[start] < maxLevel) {
709 ++start;
710 }
711 if (start >= levels.length) {
712 break; /* no more such runs */
713 }
714
715 /* look for the limit of such a sequence (the index behind it) */
716 for (limit = start; ++limit < levels.length && levels[limit] >= maxLevel; ) {}
717
718 /*
719 * Swap the entire interval of indexes from start to limit-1.
720 * We don't need to swap the levels for the purpose of this
721 * algorithm: the sequence of levels that we look at does not
722 * move anyway.
723 */
724 end = limit - 1;
725 while (start < end) {
726 temp = indexMap[start];
727 indexMap[start] = indexMap[end];
728 indexMap[end] = temp;
729
730 ++start;
731 --end;
732 }
733
734 if (limit == levels.length) {
735 break; /* no more such sequences */
736 } else {
737 start = limit + 1;
738 }
739 }
740 } while (--maxLevel >= minLevel);
741
742 return indexMap;
743 }
744
745 static int[] getVisualMap(BidiBase bidiBase)
746 {
747 /* fill a visual-to-logical index map using the runs[] */
748 BidiRun[] runs = bidiBase.runs;
749 int logicalStart, visualStart, visualLimit;
750 int allocLength = bidiBase.length > bidiBase.resultLength ? bidiBase.length
751 : bidiBase.resultLength;
752 int[] indexMap = new int[allocLength];
753
754 visualStart = 0;
755 int idx = 0;
756 for (int j = 0; j < bidiBase.runCount; ++j) {
757 logicalStart = runs[j].start;
758 visualLimit = runs[j].limit;
759 if (runs[j].isEvenRun()) {
760 do { /* LTR */
761 indexMap[idx++] = logicalStart++;
762 } while (++visualStart < visualLimit);
763 } else {
764 logicalStart += visualLimit - visualStart; /* logicalLimit */
765 do { /* RTL */
766 indexMap[idx++] = --logicalStart;
767 } while (++visualStart < visualLimit);
768 }
769 /* visualStart==visualLimit; */
770 }
771
772 if (bidiBase.insertPoints.size > 0) {
773 int markFound = 0, runCount = bidiBase.runCount;
774 int insertRemove, i, j, k;
775 runs = bidiBase.runs;
776 /* count all inserted marks */
777 for (i = 0; i < runCount; i++) {
778 insertRemove = runs[i].insertRemove;
779 if ((insertRemove & (BidiBase.LRM_BEFORE|BidiBase.RLM_BEFORE)) > 0) {
780 markFound++;
781 }
782 if ((insertRemove & (BidiBase.LRM_AFTER|BidiBase.RLM_AFTER)) > 0) {
783 markFound++;
784 }
785 }
786 /* move back indexes by number of preceding marks */
787 k = bidiBase.resultLength;
788 for (i = runCount - 1; i >= 0 && markFound > 0; i--) {
789 insertRemove = runs[i].insertRemove;
790 if ((insertRemove & (BidiBase.LRM_AFTER|BidiBase.RLM_AFTER)) > 0) {
791 indexMap[--k] = BidiBase.MAP_NOWHERE;
792 markFound--;
793 }
794 visualStart = i > 0 ? runs[i-1].limit : 0;
795 for (j = runs[i].limit - 1; j >= visualStart && markFound > 0; j--) {
796 indexMap[--k] = indexMap[j];
797 }
798 if ((insertRemove & (BidiBase.LRM_BEFORE|BidiBase.RLM_BEFORE)) > 0) {
799 indexMap[--k] = BidiBase.MAP_NOWHERE;
800 markFound--;
801 }
802 }
803 }
804 else if (bidiBase.controlCount > 0) {
805 int runCount = bidiBase.runCount, logicalEnd;
806 int insertRemove, length, i, j, k, m;
807 char uchar;
808 boolean evenRun;
809 runs = bidiBase.runs;
810 visualStart = 0;
811 /* move forward indexes by number of preceding controls */
812 k = 0;
813 for (i = 0; i < runCount; i++, visualStart += length) {
814 length = runs[i].limit - visualStart;
815 insertRemove = runs[i].insertRemove;
816 /* if no control found yet, nothing to do in this run */
817 if ((insertRemove == 0) && (k == visualStart)) {
818 k += length;
819 continue;
820 }
821 /* if no control in this run */
822 if (insertRemove == 0) {
823 visualLimit = runs[i].limit;
824 for (j = visualStart; j < visualLimit; j++) {
825 indexMap[k++] = indexMap[j];
826 }
827 continue;
828 }
829 logicalStart = runs[i].start;
830 evenRun = runs[i].isEvenRun();
831 logicalEnd = logicalStart + length - 1;
832 for (j = 0; j < length; j++) {
833 m = evenRun ? logicalStart + j : logicalEnd - j;
834 uchar = bidiBase.text[m];
835 if (!BidiBase.IsBidiControlChar(uchar)) {
836 indexMap[k++] = m;
837 }
838 }
839 }
840 }
841 if (allocLength == bidiBase.resultLength) {
842 return indexMap;
843 }
844 int[] newMap = new int[bidiBase.resultLength];
845 System.arraycopy(indexMap, 0, newMap, 0, bidiBase.resultLength);
846 return newMap;
847 }
848
849 }