1 /*
2 * Copyright (c) 2009, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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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
37 /* FOOD FOR THOUGHT: currently the reordering modes are a mixture of
38 * algorithm for direct BiDi, algorithm for inverse Bidi and the bizarre
39 * concept of RUNS_ONLY which is a double operation.
40 * It could be advantageous to divide this into 3 concepts:
41 * a) Operation: direct / inverse / RUNS_ONLY
42 * b) Direct algorithm: default / NUMBERS_SPECIAL / GROUP_NUMBERS_WITH_L
43 * c) Inverse algorithm: default / INVERSE_LIKE_DIRECT / NUMBERS_SPECIAL
44 * This would allow combinations not possible today like RUNS_ONLY with
45 * NUMBERS_SPECIAL.
46 * Also allow to set INSERT_MARKS for the direct step of RUNS_ONLY and
47 * REMOVE_CONTROLS for the inverse step.
48 * Not all combinations would be supported, and probably not all do make sense.
49 * This would need to document which ones are supported and what are the
50 * fallbacks for unsupported combinations.
51 */
52
53 package sun.text.bidi;
54
55 import java.io.IOException;
56 import java.lang.reflect.Array;
57 import java.text.AttributedCharacterIterator;
58 import java.text.Bidi;
59 import java.util.Arrays;
60 import java.util.MissingResourceException;
61 import sun.misc.JavaAWTFontAccess;
62 import sun.misc.SharedSecrets;
63 import sun.text.normalizer.UBiDiProps;
64 import sun.text.normalizer.UCharacter;
65 import sun.text.normalizer.UTF16;
66
67 /**
68 *
69 * <h2>Bidi algorithm for ICU</h2>
70 *
71 * This is an implementation of the Unicode Bidirectional algorithm. The
72 * algorithm is defined in the <a
73 * href="http://www.unicode.org/unicode/reports/tr9/">Unicode Standard Annex #9</a>,
74 * version 13, also described in The Unicode Standard, Version 4.0 .
75 * <p>
76 *
77 * Note: Libraries that perform a bidirectional algorithm and reorder strings
78 * accordingly are sometimes called "Storage Layout Engines". ICU's Bidi and
79 * shaping (ArabicShaping) classes can be used at the core of such "Storage
80 * Layout Engines".
81 *
82 * <h3>General remarks about the API:</h3>
83 *
84 * The "limit" of a sequence of characters is the position just after
85 * their last character, i.e., one more than that position.
86 * <p>
87 *
88 * Some of the API methods provide access to "runs". Such a
89 * "run" is defined as a sequence of characters that are at the same
90 * embedding level after performing the Bidi algorithm.
91 * <p>
92 *
93 * <h3>Basic concept: paragraph</h3>
94 * A piece of text can be divided into several paragraphs by characters
95 * with the Bidi class <code>Block Separator</code>. For handling of
96 * paragraphs, see:
97 * <ul>
98 * <li>{@link #countParagraphs}
99 * <li>{@link #getParaLevel}
100 * <li>{@link #getParagraph}
101 * <li>{@link #getParagraphByIndex}
102 * </ul>
103 *
104 * <h3>Basic concept: text direction</h3>
105 * The direction of a piece of text may be:
106 * <ul>
107 * <li>{@link #LTR}
108 * <li>{@link #RTL}
109 * <li>{@link #MIXED}
110 * </ul>
111 *
112 * <h3>Basic concept: levels</h3>
113 *
114 * Levels in this API represent embedding levels according to the Unicode
115 * Bidirectional Algorithm.
116 * Their low-order bit (even/odd value) indicates the visual direction.<p>
117 *
118 * Levels can be abstract values when used for the
119 * <code>paraLevel</code> and <code>embeddingLevels</code>
120 * arguments of <code>setPara()</code>; there:
121 * <ul>
122 * <li>the high-order bit of an <code>embeddingLevels[]</code>
123 * value indicates whether the using application is
124 * specifying the level of a character to <i>override</i> whatever the
125 * Bidi implementation would resolve it to.</li>
126 * <li><code>paraLevel</code> can be set to the
127 * pseudo-level values <code>LEVEL_DEFAULT_LTR</code>
128 * and <code>LEVEL_DEFAULT_RTL</code>.</li>
129 * </ul>
130 *
131 * <p>The related constants are not real, valid level values.
132 * <code>DEFAULT_XXX</code> can be used to specify
133 * a default for the paragraph level for
134 * when the <code>setPara()</code> method
135 * shall determine it but there is no
136 * strongly typed character in the input.<p>
137 *
138 * Note that the value for <code>LEVEL_DEFAULT_LTR</code> is even
139 * and the one for <code>LEVEL_DEFAULT_RTL</code> is odd,
140 * just like with normal LTR and RTL level values -
141 * these special values are designed that way. Also, the implementation
142 * assumes that MAX_EXPLICIT_LEVEL is odd.
143 *
144 * <ul><b>See Also:</b>
145 * <li>{@link #LEVEL_DEFAULT_LTR}
146 * <li>{@link #LEVEL_DEFAULT_RTL}
147 * <li>{@link #LEVEL_OVERRIDE}
148 * <li>{@link #MAX_EXPLICIT_LEVEL}
149 * <li>{@link #setPara}
150 * </ul>
151 *
152 * <h3>Basic concept: Reordering Mode</h3>
153 * Reordering mode values indicate which variant of the Bidi algorithm to
154 * use.
155 *
156 * <ul><b>See Also:</b>
157 * <li>{@link #setReorderingMode}
158 * <li>{@link #REORDER_DEFAULT}
159 * <li>{@link #REORDER_NUMBERS_SPECIAL}
160 * <li>{@link #REORDER_GROUP_NUMBERS_WITH_R}
161 * <li>{@link #REORDER_RUNS_ONLY}
162 * <li>{@link #REORDER_INVERSE_NUMBERS_AS_L}
163 * <li>{@link #REORDER_INVERSE_LIKE_DIRECT}
164 * <li>{@link #REORDER_INVERSE_FOR_NUMBERS_SPECIAL}
165 * </ul>
166 *
167 * <h3>Basic concept: Reordering Options</h3>
168 * Reordering options can be applied during Bidi text transformations.
169 * <ul><b>See Also:</b>
170 * <li>{@link #setReorderingOptions}
171 * <li>{@link #OPTION_DEFAULT}
172 * <li>{@link #OPTION_INSERT_MARKS}
173 * <li>{@link #OPTION_REMOVE_CONTROLS}
174 * <li>{@link #OPTION_STREAMING}
175 * </ul>
176 *
177 *
178 * @author Simon Montagu, Matitiahu Allouche (ported from C code written by Markus W. Scherer)
179 * @stable ICU 3.8
180 *
181 *
182 * <h4> Sample code for the ICU Bidi API </h4>
183 *
184 * <h5>Rendering a paragraph with the ICU Bidi API</h5>
185 *
186 * This is (hypothetical) sample code that illustrates how the ICU Bidi API
187 * could be used to render a paragraph of text. Rendering code depends highly on
188 * the graphics system, therefore this sample code must make a lot of
189 * assumptions, which may or may not match any existing graphics system's
190 * properties.
191 *
192 * <p>
193 * The basic assumptions are:
194 * </p>
195 * <ul>
196 * <li>Rendering is done from left to right on a horizontal line.</li>
197 * <li>A run of single-style, unidirectional text can be rendered at once.
198 * </li>
199 * <li>Such a run of text is passed to the graphics system with characters
200 * (code units) in logical order.</li>
201 * <li>The line-breaking algorithm is very complicated and Locale-dependent -
202 * and therefore its implementation omitted from this sample code.</li>
203 * </ul>
204 *
205 * <pre>
206 *
207 * package com.ibm.icu.dev.test.bidi;
208 *
209 * import com.ibm.icu.text.Bidi;
210 * import com.ibm.icu.text.BidiRun;
211 *
212 * public class Sample {
213 *
214 * static final int styleNormal = 0;
215 * static final int styleSelected = 1;
216 * static final int styleBold = 2;
217 * static final int styleItalics = 4;
218 * static final int styleSuper=8;
219 * static final int styleSub = 16;
220 *
221 * static class StyleRun {
222 * int limit;
223 * int style;
224 *
225 * public StyleRun(int limit, int style) {
226 * this.limit = limit;
227 * this.style = style;
228 * }
229 * }
230 *
231 * static class Bounds {
232 * int start;
233 * int limit;
234 *
235 * public Bounds(int start, int limit) {
236 * this.start = start;
237 * this.limit = limit;
238 * }
239 * }
240 *
241 * static int getTextWidth(String text, int start, int limit,
242 * StyleRun[] styleRuns, int styleRunCount) {
243 * // simplistic way to compute the width
244 * return limit - start;
245 * }
246 *
247 * // set limit and StyleRun limit for a line
248 * // from text[start] and from styleRuns[styleRunStart]
249 * // using Bidi.getLogicalRun(...)
250 * // returns line width
251 * static int getLineBreak(String text, Bounds line, Bidi para,
252 * StyleRun styleRuns[], Bounds styleRun) {
253 * // dummy return
254 * return 0;
255 * }
256 *
257 * // render runs on a line sequentially, always from left to right
258 *
259 * // prepare rendering a new line
260 * static void startLine(byte textDirection, int lineWidth) {
261 * System.out.println();
262 * }
263 *
264 * // render a run of text and advance to the right by the run width
265 * // the text[start..limit-1] is always in logical order
266 * static void renderRun(String text, int start, int limit,
267 * byte textDirection, int style) {
268 * }
269 *
270 * // We could compute a cross-product
271 * // from the style runs with the directional runs
272 * // and then reorder it.
273 * // Instead, here we iterate over each run type
274 * // and render the intersections -
275 * // with shortcuts in simple (and common) cases.
276 * // renderParagraph() is the main function.
277 *
278 * // render a directional run with
279 * // (possibly) multiple style runs intersecting with it
280 * static void renderDirectionalRun(String text, int start, int limit,
281 * byte direction, StyleRun styleRuns[],
282 * int styleRunCount) {
283 * int i;
284 *
285 * // iterate over style runs
286 * if (direction == Bidi.LTR) {
287 * int styleLimit;
288 * for (i = 0; i < styleRunCount; ++i) {
289 * styleLimit = styleRuns[i].limit;
290 * if (start < styleLimit) {
291 * if (styleLimit > limit) {
292 * styleLimit = limit;
293 * }
294 * renderRun(text, start, styleLimit,
295 * direction, styleRuns[i].style);
296 * if (styleLimit == limit) {
297 * break;
298 * }
299 * start = styleLimit;
300 * }
301 * }
302 * } else {
303 * int styleStart;
304 *
305 * for (i = styleRunCount-1; i >= 0; --i) {
306 * if (i > 0) {
307 * styleStart = styleRuns[i-1].limit;
308 * } else {
309 * styleStart = 0;
310 * }
311 * if (limit >= styleStart) {
312 * if (styleStart < start) {
313 * styleStart = start;
314 * }
315 * renderRun(text, styleStart, limit, direction,
316 * styleRuns[i].style);
317 * if (styleStart == start) {
318 * break;
319 * }
320 * limit = styleStart;
321 * }
322 * }
323 * }
324 * }
325 *
326 * // the line object represents text[start..limit-1]
327 * static void renderLine(Bidi line, String text, int start, int limit,
328 * StyleRun styleRuns[], int styleRunCount) {
329 * byte direction = line.getDirection();
330 * if (direction != Bidi.MIXED) {
331 * // unidirectional
332 * if (styleRunCount <= 1) {
333 * renderRun(text, start, limit, direction, styleRuns[0].style);
334 * } else {
335 * renderDirectionalRun(text, start, limit, direction,
336 * styleRuns, styleRunCount);
337 * }
338 * } else {
339 * // mixed-directional
340 * int count, i;
341 * BidiRun run;
342 *
343 * try {
344 * count = line.countRuns();
345 * } catch (IllegalStateException e) {
346 * e.printStackTrace();
347 * return;
348 * }
349 * if (styleRunCount <= 1) {
350 * int style = styleRuns[0].style;
351 *
352 * // iterate over directional runs
353 * for (i = 0; i < count; ++i) {
354 * run = line.getVisualRun(i);
355 * renderRun(text, run.getStart(), run.getLimit(),
356 * run.getDirection(), style);
357 * }
358 * } else {
359 * // iterate over both directional and style runs
360 * for (i = 0; i < count; ++i) {
361 * run = line.getVisualRun(i);
362 * renderDirectionalRun(text, run.getStart(),
363 * run.getLimit(), run.getDirection(),
364 * styleRuns, styleRunCount);
365 * }
366 * }
367 * }
368 * }
369 *
370 * static void renderParagraph(String text, byte textDirection,
371 * StyleRun styleRuns[], int styleRunCount,
372 * int lineWidth) {
373 * int length = text.length();
374 * Bidi para = new Bidi();
375 * try {
376 * para.setPara(text,
377 * textDirection != 0 ? Bidi.LEVEL_DEFAULT_RTL
378 * : Bidi.LEVEL_DEFAULT_LTR,
379 * null);
380 * } catch (Exception e) {
381 * e.printStackTrace();
382 * return;
383 * }
384 * byte paraLevel = (byte)(1 & para.getParaLevel());
385 * StyleRun styleRun = new StyleRun(length, styleNormal);
386 *
387 * if (styleRuns == null || styleRunCount <= 0) {
388 * styleRuns = new StyleRun[1];
389 * styleRunCount = 1;
390 * styleRuns[0] = styleRun;
391 * }
392 * // assume styleRuns[styleRunCount-1].limit>=length
393 *
394 * int width = getTextWidth(text, 0, length, styleRuns, styleRunCount);
395 * if (width <= lineWidth) {
396 * // everything fits onto one line
397 *
398 * // prepare rendering a new line from either left or right
399 * startLine(paraLevel, width);
400 *
401 * renderLine(para, text, 0, length, styleRuns, styleRunCount);
402 * } else {
403 * // we need to render several lines
404 * Bidi line = new Bidi(length, 0);
405 * int start = 0, limit;
406 * int styleRunStart = 0, styleRunLimit;
407 *
408 * for (;;) {
409 * limit = length;
410 * styleRunLimit = styleRunCount;
411 * width = getLineBreak(text, new Bounds(start, limit),
412 * para, styleRuns,
413 * new Bounds(styleRunStart, styleRunLimit));
414 * try {
415 * line = para.setLine(start, limit);
416 * } catch (Exception e) {
417 * e.printStackTrace();
418 * return;
419 * }
420 * // prepare rendering a new line
421 * // from either left or right
422 * startLine(paraLevel, width);
423 *
424 * if (styleRunStart > 0) {
425 * int newRunCount = styleRuns.length - styleRunStart;
426 * StyleRun[] newRuns = new StyleRun[newRunCount];
427 * System.arraycopy(styleRuns, styleRunStart, newRuns, 0,
428 * newRunCount);
429 * renderLine(line, text, start, limit, newRuns,
430 * styleRunLimit - styleRunStart);
431 * } else {
432 * renderLine(line, text, start, limit, styleRuns,
433 * styleRunLimit - styleRunStart);
434 * }
435 * if (limit == length) {
436 * break;
437 * }
438 * start = limit;
439 * styleRunStart = styleRunLimit - 1;
440 * if (start >= styleRuns[styleRunStart].limit) {
441 * ++styleRunStart;
442 * }
443 * }
444 * }
445 * }
446 *
447 * public static void main(String[] args)
448 * {
449 * renderParagraph("Some Latin text...", Bidi.LTR, null, 0, 80);
450 * renderParagraph("Some Hebrew text...", Bidi.RTL, null, 0, 60);
451 * }
452 * }
453 *
454 * </pre>
455 */
456
457 public class BidiBase {
458
459 class Point {
460 int pos; /* position in text */
461 int flag; /* flag for LRM/RLM, before/after */
462 }
463
464 class InsertPoints {
465 int size;
466 int confirmed;
467 Point[] points = new Point[0];
468 }
469
470 /** Paragraph level setting<p>
471 *
472 * Constant indicating that the base direction depends on the first strong
473 * directional character in the text according to the Unicode Bidirectional
474 * Algorithm. If no strong directional character is present,
475 * then set the paragraph level to 0 (left-to-right).<p>
476 *
477 * If this value is used in conjunction with reordering modes
478 * <code>REORDER_INVERSE_LIKE_DIRECT</code> or
479 * <code>REORDER_INVERSE_FOR_NUMBERS_SPECIAL</code>, the text to reorder
480 * is assumed to be visual LTR, and the text after reordering is required
481 * to be the corresponding logical string with appropriate contextual
482 * direction. The direction of the result string will be RTL if either
483 * the righmost or leftmost strong character of the source text is RTL
484 * or Arabic Letter, the direction will be LTR otherwise.<p>
485 *
486 * If reordering option <code>OPTION_INSERT_MARKS</code> is set, an RLM may
487 * be added at the beginning of the result string to ensure round trip
488 * (that the result string, when reordered back to visual, will produce
489 * the original source text).
490 * @see #REORDER_INVERSE_LIKE_DIRECT
491 * @see #REORDER_INVERSE_FOR_NUMBERS_SPECIAL
492 * @stable ICU 3.8
493 */
494 public static final byte INTERNAL_LEVEL_DEFAULT_LTR = (byte)0x7e;
495
496 /** Paragraph level setting<p>
497 *
498 * Constant indicating that the base direction depends on the first strong
499 * directional character in the text according to the Unicode Bidirectional
500 * Algorithm. If no strong directional character is present,
501 * then set the paragraph level to 1 (right-to-left).<p>
502 *
503 * If this value is used in conjunction with reordering modes
504 * <code>REORDER_INVERSE_LIKE_DIRECT</code> or
505 * <code>REORDER_INVERSE_FOR_NUMBERS_SPECIAL</code>, the text to reorder
506 * is assumed to be visual LTR, and the text after reordering is required
507 * to be the corresponding logical string with appropriate contextual
508 * direction. The direction of the result string will be RTL if either
509 * the righmost or leftmost strong character of the source text is RTL
510 * or Arabic Letter, or if the text contains no strong character;
511 * the direction will be LTR otherwise.<p>
512 *
513 * If reordering option <code>OPTION_INSERT_MARKS</code> is set, an RLM may
514 * be added at the beginning of the result string to ensure round trip
515 * (that the result string, when reordered back to visual, will produce
516 * the original source text).
517 * @see #REORDER_INVERSE_LIKE_DIRECT
518 * @see #REORDER_INVERSE_FOR_NUMBERS_SPECIAL
519 * @stable ICU 3.8
520 */
521 public static final byte INTERNAL_LEVEL_DEFAULT_RTL = (byte)0x7f;
522
523 /**
524 * Maximum explicit embedding level.
525 * (The maximum resolved level can be up to <code>MAX_EXPLICIT_LEVEL+1</code>).
526 * @stable ICU 3.8
527 */
528 public static final byte MAX_EXPLICIT_LEVEL = 61;
529
530 /**
531 * Bit flag for level input.
532 * Overrides directional properties.
533 * @stable ICU 3.8
534 */
535 public static final byte INTERNAL_LEVEL_OVERRIDE = (byte)0x80;
536
537 /**
538 * Special value which can be returned by the mapping methods when a
539 * logical index has no corresponding visual index or vice-versa. This may
540 * happen for the logical-to-visual mapping of a Bidi control when option
541 * <code>OPTION_REMOVE_CONTROLS</code> is
542 * specified. This can also happen for the visual-to-logical mapping of a
543 * Bidi mark (LRM or RLM) inserted by option
544 * <code>OPTION_INSERT_MARKS</code>.
545 * @see #getVisualIndex
546 * @see #getVisualMap
547 * @see #getLogicalIndex
548 * @see #getLogicalMap
549 * @see #OPTION_INSERT_MARKS
550 * @see #OPTION_REMOVE_CONTROLS
551 * @stable ICU 3.8
552 */
553 public static final int MAP_NOWHERE = -1;
554
555 /**
556 * Mixed-directional text.
557 * @stable ICU 3.8
558 */
559 public static final byte MIXED = 2;
560
561 /**
562 * option bit for writeReordered():
563 * replace characters with the "mirrored" property in RTL runs
564 * by their mirror-image mappings
565 *
566 * @see #writeReordered
567 * @stable ICU 3.8
568 */
569 public static final short DO_MIRRORING = 2;
570
571 /** Reordering mode: Regular Logical to Visual Bidi algorithm according to Unicode.
572 * @see #setReorderingMode
573 * @stable ICU 3.8
574 */
575 private static final short REORDER_DEFAULT = 0;
576
577 /** Reordering mode: Logical to Visual algorithm which handles numbers in
578 * a way which mimicks the behavior of Windows XP.
579 * @see #setReorderingMode
580 * @stable ICU 3.8
581 */
582 private static final short REORDER_NUMBERS_SPECIAL = 1;
583
584 /** Reordering mode: Logical to Visual algorithm grouping numbers with
585 * adjacent R characters (reversible algorithm).
586 * @see #setReorderingMode
587 * @stable ICU 3.8
588 */
589 private static final short REORDER_GROUP_NUMBERS_WITH_R = 2;
590
591 /** Reordering mode: Reorder runs only to transform a Logical LTR string
592 * to the logical RTL string with the same display, or vice-versa.<br>
593 * If this mode is set together with option
594 * <code>OPTION_INSERT_MARKS</code>, some Bidi controls in the source
595 * text may be removed and other controls may be added to produce the
596 * minimum combination which has the required display.
597 * @see #OPTION_INSERT_MARKS
598 * @see #setReorderingMode
599 * @stable ICU 3.8
600 */
601 private static final short REORDER_RUNS_ONLY = 3;
602
603 /** Reordering mode: Visual to Logical algorithm which handles numbers
604 * like L (same algorithm as selected by <code>setInverse(true)</code>.
605 * @see #setInverse
606 * @see #setReorderingMode
607 * @stable ICU 3.8
608 */
609 private static final short REORDER_INVERSE_NUMBERS_AS_L = 4;
610
611 /** Reordering mode: Visual to Logical algorithm equivalent to the regular
612 * Logical to Visual algorithm.
613 * @see #setReorderingMode
614 * @stable ICU 3.8
615 */
616 private static final short REORDER_INVERSE_LIKE_DIRECT = 5;
617
618 /** Reordering mode: Inverse Bidi (Visual to Logical) algorithm for the
619 * <code>REORDER_NUMBERS_SPECIAL</code> Bidi algorithm.
620 * @see #setReorderingMode
621 * @stable ICU 3.8
622 */
623 private static final short REORDER_INVERSE_FOR_NUMBERS_SPECIAL = 6;
624
625 /* Reordering mode values must be ordered so that all the regular logical to
626 * visual modes come first, and all inverse Bidi modes come last.
627 */
628 private static final short REORDER_LAST_LOGICAL_TO_VISUAL =
629 REORDER_NUMBERS_SPECIAL;
630
631 /**
632 * Option bit for <code>setReorderingOptions</code>:
633 * insert Bidi marks (LRM or RLM) when needed to ensure correct result of
634 * a reordering to a Logical order
635 *
636 * <p>This option must be set or reset before calling
637 * <code>setPara</code>.</p>
638 *
639 * <p>This option is significant only with reordering modes which generate
640 * a result with Logical order, specifically.</p>
641 * <ul>
642 * <li><code>REORDER_RUNS_ONLY</code></li>
643 * <li><code>REORDER_INVERSE_NUMBERS_AS_L</code></li>
644 * <li><code>REORDER_INVERSE_LIKE_DIRECT</code></li>
645 * <li><code>REORDER_INVERSE_FOR_NUMBERS_SPECIAL</code></li>
646 * </ul>
647 *
648 * <p>If this option is set in conjunction with reordering mode
649 * <code>REORDER_INVERSE_NUMBERS_AS_L</code> or with calling
650 * <code>setInverse(true)</code>, it implies option
651 * <code>INSERT_LRM_FOR_NUMERIC</code> in calls to method
652 * <code>writeReordered()</code>.</p>
653 *
654 * <p>For other reordering modes, a minimum number of LRM or RLM characters
655 * will be added to the source text after reordering it so as to ensure
656 * round trip, i.e. when applying the inverse reordering mode on the
657 * resulting logical text with removal of Bidi marks
658 * (option <code>OPTION_REMOVE_CONTROLS</code> set before calling
659 * <code>setPara()</code> or option
660 * <code>REMOVE_BIDI_CONTROLS</code> in
661 * <code>writeReordered</code>), the result will be identical to the
662 * source text in the first transformation.
663 *
664 * <p>This option will be ignored if specified together with option
665 * <code>OPTION_REMOVE_CONTROLS</code>. It inhibits option
666 * <code>REMOVE_BIDI_CONTROLS</code> in calls to method
667 * <code>writeReordered()</code> and it implies option
668 * <code>INSERT_LRM_FOR_NUMERIC</code> in calls to method
669 * <code>writeReordered()</code> if the reordering mode is
670 * <code>REORDER_INVERSE_NUMBERS_AS_L</code>.</p>
671 *
672 * @see #setReorderingMode
673 * @see #setReorderingOptions
674 * @see #INSERT_LRM_FOR_NUMERIC
675 * @see #REMOVE_BIDI_CONTROLS
676 * @see #OPTION_REMOVE_CONTROLS
677 * @see #REORDER_RUNS_ONLY
678 * @see #REORDER_INVERSE_NUMBERS_AS_L
679 * @see #REORDER_INVERSE_LIKE_DIRECT
680 * @see #REORDER_INVERSE_FOR_NUMBERS_SPECIAL
681 * @stable ICU 3.8
682 */
683 private static final int OPTION_INSERT_MARKS = 1;
684
685 /**
686 * Option bit for <code>setReorderingOptions</code>:
687 * remove Bidi control characters
688 *
689 * <p>This option must be set or reset before calling
690 * <code>setPara</code>.</p>
691 *
692 * <p>This option nullifies option
693 * <code>OPTION_INSERT_MARKS</code>. It inhibits option
694 * <code>INSERT_LRM_FOR_NUMERIC</code> in calls to method
695 * <code>writeReordered()</code> and it implies option
696 * <code>REMOVE_BIDI_CONTROLS</code> in calls to that method.</p>
697 *
698 * @see #setReorderingMode
699 * @see #setReorderingOptions
700 * @see #OPTION_INSERT_MARKS
701 * @see #INSERT_LRM_FOR_NUMERIC
702 * @see #REMOVE_BIDI_CONTROLS
703 * @stable ICU 3.8
704 */
705 private static final int OPTION_REMOVE_CONTROLS = 2;
706
707 /**
708 * Option bit for <code>setReorderingOptions</code>:
709 * process the output as part of a stream to be continued
710 *
711 * <p>This option must be set or reset before calling
712 * <code>setPara</code>.</p>
713 *
714 * <p>This option specifies that the caller is interested in processing
715 * large text object in parts. The results of the successive calls are
716 * expected to be concatenated by the caller. Only the call for the last
717 * part will have this option bit off.</p>
718 *
719 * <p>When this option bit is on, <code>setPara()</code> may process
720 * less than the full source text in order to truncate the text at a
721 * meaningful boundary. The caller should call
722 * <code>getProcessedLength()</code> immediately after calling
723 * <code>setPara()</code> in order to determine how much of the source
724 * text has been processed. Source text beyond that length should be
725 * resubmitted in following calls to <code>setPara</code>. The
726 * processed length may be less than the length of the source text if a
727 * character preceding the last character of the source text constitutes a
728 * reasonable boundary (like a block separator) for text to be continued.<br>
729 * If the last character of the source text constitutes a reasonable
730 * boundary, the whole text will be processed at once.<br>
731 * If nowhere in the source text there exists
732 * such a reasonable boundary, the processed length will be zero.<br>
733 * The caller should check for such an occurrence and do one of the following:
734 * <ul><li>submit a larger amount of text with a better chance to include
735 * a reasonable boundary.</li>
736 * <li>resubmit the same text after turning off option
737 * <code>OPTION_STREAMING</code>.</li></ul>
738 * In all cases, this option should be turned off before processing the last
739 * part of the text.</p>
740 *
741 * <p>When the <code>OPTION_STREAMING</code> option is used, it is
742 * recommended to call <code>orderParagraphsLTR()</code> with argument
743 * <code>orderParagraphsLTR</code> set to <code>true</code> before calling
744 * <code>setPara()</code> so that later paragraphs may be concatenated to
745 * previous paragraphs on the right.
746 * </p>
747 *
748 * @see #setReorderingMode
749 * @see #setReorderingOptions
750 * @see #getProcessedLength
751 * @see #orderParagraphsLTR
752 * @stable ICU 3.8
753 */
754 private static final int OPTION_STREAMING = 4;
755
756 /*
757 * Comparing the description of the Bidi algorithm with this implementation
758 * is easier with the same names for the Bidi types in the code as there.
759 * See UCharacterDirection
760 */
761 private static final byte L = 0;
762 private static final byte R = 1;
763 private static final byte EN = 2;
764 private static final byte ES = 3;
765 private static final byte ET = 4;
766 private static final byte AN = 5;
767 private static final byte CS = 6;
768 static final byte B = 7;
769 private static final byte S = 8;
770 private static final byte WS = 9;
771 private static final byte ON = 10;
772 private static final byte LRE = 11;
773 private static final byte LRO = 12;
774 private static final byte AL = 13;
775 private static final byte RLE = 14;
776 private static final byte RLO = 15;
777 private static final byte PDF = 16;
778 private static final byte NSM = 17;
779 private static final byte BN = 18;
780
781 private static final int MASK_R_AL = (1 << R | 1 << AL);
782
783 private static final char CR = '\r';
784 private static final char LF = '\n';
785
786 static final int LRM_BEFORE = 1;
787 static final int LRM_AFTER = 2;
788 static final int RLM_BEFORE = 4;
789 static final int RLM_AFTER = 8;
790
791 /*
792 * reference to parent paragraph object (reference to self if this object is
793 * a paragraph object); set to null in a newly opened object; set to a
794 * real value after a successful execution of setPara or setLine
795 */
796 BidiBase paraBidi;
797
798 final UBiDiProps bdp;
799
800 /* character array representing the current text */
801 char[] text;
802
803 /* length of the current text */
804 int originalLength;
805
806 /* if the option OPTION_STREAMING is set, this is the length of
807 * text actually processed by <code>setPara</code>, which may be shorter
808 * than the original length. Otherwise, it is identical to the original
809 * length.
810 */
811 public int length;
812
813 /* if option OPTION_REMOVE_CONTROLS is set, and/or Bidi
814 * marks are allowed to be inserted in one of the reordering modes, the
815 * length of the result string may be different from the processed length.
816 */
817 int resultLength;
818
819 /* indicators for whether memory may be allocated after construction */
820 boolean mayAllocateText;
821 boolean mayAllocateRuns;
822
823 /* arrays with one value per text-character */
824 byte[] dirPropsMemory = new byte[1];
825 byte[] levelsMemory = new byte[1];
826 byte[] dirProps;
827 byte[] levels;
828
829 /* must block separators receive level 0? */
830 boolean orderParagraphsLTR;
831
832 /* the paragraph level */
833 byte paraLevel;
834
835 /* original paraLevel when contextual */
836 /* must be one of DEFAULT_xxx or 0 if not contextual */
837 byte defaultParaLevel;
838
839 /* the following is set in setPara, used in processPropertySeq */
840
841 ImpTabPair impTabPair; /* reference to levels state table pair */
842
843 /* the overall paragraph or line directionality*/
844 byte direction;
845
846 /* flags is a bit set for which directional properties are in the text */
847 int flags;
848
849 /* lastArabicPos is index to the last AL in the text, -1 if none */
850 int lastArabicPos;
851
852 /* characters after trailingWSStart are WS and are */
853 /* implicitly at the paraLevel (rule (L1)) - levels may not reflect that */
854 int trailingWSStart;
855
856 /* fields for paragraph handling */
857 int paraCount; /* set in getDirProps() */
858 int[] parasMemory = new int[1];
859 int[] paras; /* limits of paragraphs, filled in
860 ResolveExplicitLevels() or CheckExplicitLevels() */
861
862 /* for single paragraph text, we only need a tiny array of paras (no allocation) */
863 int[] simpleParas = {0};
864
865 /* fields for line reordering */
866 int runCount; /* ==-1: runs not set up yet */
867 BidiRun[] runsMemory = new BidiRun[0];
868 BidiRun[] runs;
869
870 /* for non-mixed text, we only need a tiny array of runs (no allocation) */
871 BidiRun[] simpleRuns = {new BidiRun()};
872
873 /* mapping of runs in logical order to visual order */
874 int[] logicalToVisualRunsMap;
875
876 /* flag to indicate that the map has been updated */
877 boolean isGoodLogicalToVisualRunsMap;
878
879 /* for inverse Bidi with insertion of directional marks */
880 InsertPoints insertPoints = new InsertPoints();
881
882 /* for option OPTION_REMOVE_CONTROLS */
883 int controlCount;
884
885 /*
886 * Sometimes, bit values are more appropriate
887 * to deal with directionality properties.
888 * Abbreviations in these method names refer to names
889 * used in the Bidi algorithm.
890 */
891 static int DirPropFlag(byte dir) {
892 return (1 << dir);
893 }
894
895 /*
896 * The following bit is ORed to the property of characters in paragraphs
897 * with contextual RTL direction when paraLevel is contextual.
898 */
899 static final byte CONTEXT_RTL_SHIFT = 6;
900 static final byte CONTEXT_RTL = (byte)(1<<CONTEXT_RTL_SHIFT); // 0x40
901 static byte NoContextRTL(byte dir)
902 {
903 return (byte)(dir & ~CONTEXT_RTL);
904 }
905
906 /*
907 * The following is a variant of DirProp.DirPropFlag() which ignores the
908 * CONTEXT_RTL bit.
909 */
910 static int DirPropFlagNC(byte dir) {
911 return (1<<(dir & ~CONTEXT_RTL));
912 }
913
914 static final int DirPropFlagMultiRuns = DirPropFlag((byte)31);
915
916 /* to avoid some conditional statements, use tiny constant arrays */
917 static final int DirPropFlagLR[] = { DirPropFlag(L), DirPropFlag(R) };
918 static final int DirPropFlagE[] = { DirPropFlag(LRE), DirPropFlag(RLE) };
919 static final int DirPropFlagO[] = { DirPropFlag(LRO), DirPropFlag(RLO) };
920
921 static final int DirPropFlagLR(byte level) { return DirPropFlagLR[level & 1]; }
922 static final int DirPropFlagE(byte level) { return DirPropFlagE[level & 1]; }
923 static final int DirPropFlagO(byte level) { return DirPropFlagO[level & 1]; }
924
925 /*
926 * are there any characters that are LTR?
927 */
928 static final int MASK_LTR =
929 DirPropFlag(L)|DirPropFlag(EN)|DirPropFlag(AN)|DirPropFlag(LRE)|DirPropFlag(LRO);
930
931 /*
932 * are there any characters that are RTL?
933 */
934 static final int MASK_RTL = DirPropFlag(R)|DirPropFlag(AL)|DirPropFlag(RLE)|DirPropFlag(RLO);
935
936 /* explicit embedding codes */
937 private static final int MASK_LRX = DirPropFlag(LRE)|DirPropFlag(LRO);
938 private static final int MASK_RLX = DirPropFlag(RLE)|DirPropFlag(RLO);
939 private static final int MASK_EXPLICIT = MASK_LRX|MASK_RLX|DirPropFlag(PDF);
940 private static final int MASK_BN_EXPLICIT = DirPropFlag(BN)|MASK_EXPLICIT;
941
942 /* paragraph and segment separators */
943 private static final int MASK_B_S = DirPropFlag(B)|DirPropFlag(S);
944
945 /* all types that are counted as White Space or Neutral in some steps */
946 static final int MASK_WS = MASK_B_S|DirPropFlag(WS)|MASK_BN_EXPLICIT;
947 private static final int MASK_N = DirPropFlag(ON)|MASK_WS;
948
949 /* types that are neutrals or could becomes neutrals in (Wn) */
950 private static final int MASK_POSSIBLE_N = DirPropFlag(CS)|DirPropFlag(ES)|DirPropFlag(ET)|MASK_N;
951
952 /*
953 * These types may be changed to "e",
954 * the embedding type (L or R) of the run,
955 * in the Bidi algorithm (N2)
956 */
957 static final int MASK_EMBEDDING = DirPropFlag(NSM)|MASK_POSSIBLE_N;
958
959 /*
960 * the dirProp's L and R are defined to 0 and 1 values in UCharacterDirection.java
961 */
962 private static byte GetLRFromLevel(byte level)
963 {
964 return (byte)(level & 1);
965 }
966
967 private static boolean IsDefaultLevel(byte level)
968 {
969 return ((level & INTERNAL_LEVEL_DEFAULT_LTR) == INTERNAL_LEVEL_DEFAULT_LTR);
970 }
971
972 byte GetParaLevelAt(int index)
973 {
974 return (defaultParaLevel != 0) ?
975 (byte)(dirProps[index]>>CONTEXT_RTL_SHIFT) : paraLevel;
976 }
977
978 static boolean IsBidiControlChar(int c)
979 {
980 /* check for range 0x200c to 0x200f (ZWNJ, ZWJ, LRM, RLM) or
981 0x202a to 0x202e (LRE, RLE, PDF, LRO, RLO) */
982 return (((c & 0xfffffffc) == 0x200c) || ((c >= 0x202a) && (c <= 0x202e)));
983 }
984
985 public void verifyValidPara()
986 {
987 if (this != this.paraBidi) {
988 throw new IllegalStateException("");
989 }
990 }
991
992 public void verifyValidParaOrLine()
993 {
994 BidiBase para = this.paraBidi;
995 /* verify Para */
996 if (this == para) {
997 return;
998 }
999 /* verify Line */
1000 if ((para == null) || (para != para.paraBidi)) {
1001 throw new IllegalStateException();
1002 }
1003 }
1004
1005 public void verifyRange(int index, int start, int limit)
1006 {
1007 if (index < start || index >= limit) {
1008 throw new IllegalArgumentException("Value " + index +
1009 " is out of range " + start + " to " + limit);
1010 }
1011 }
1012
1013 public void verifyIndex(int index, int start, int limit)
1014 {
1015 if (index < start || index >= limit) {
1016 throw new ArrayIndexOutOfBoundsException("Index " + index +
1017 " is out of range " + start + " to " + limit);
1018 }
1019 }
1020
1021 /**
1022 * Allocate a <code>Bidi</code> object with preallocated memory
1023 * for internal structures.
1024 * This method provides a <code>Bidi</code> object like the default constructor
1025 * but it also preallocates memory for internal structures
1026 * according to the sizings supplied by the caller.<p>
1027 * The preallocation can be limited to some of the internal memory
1028 * by setting some values to 0 here. That means that if, e.g.,
1029 * <code>maxRunCount</code> cannot be reasonably predetermined and should not
1030 * be set to <code>maxLength</code> (the only failproof value) to avoid
1031 * wasting memory, then <code>maxRunCount</code> could be set to 0 here
1032 * and the internal structures that are associated with it will be allocated
1033 * on demand, just like with the default constructor.
1034 *
1035 * @param maxLength is the maximum text or line length that internal memory
1036 * will be preallocated for. An attempt to associate this object with a
1037 * longer text will fail, unless this value is 0, which leaves the allocation
1038 * up to the implementation.
1039 *
1040 * @param maxRunCount is the maximum anticipated number of same-level runs
1041 * that internal memory will be preallocated for. An attempt to access
1042 * visual runs on an object that was not preallocated for as many runs
1043 * as the text was actually resolved to will fail,
1044 * unless this value is 0, which leaves the allocation up to the implementation.<br><br>
1045 * The number of runs depends on the actual text and maybe anywhere between
1046 * 1 and <code>maxLength</code>. It is typically small.
1047 *
1048 * @throws IllegalArgumentException if maxLength or maxRunCount is less than 0
1049 * @stable ICU 3.8
1050 */
1051 public BidiBase(int maxLength, int maxRunCount)
1052 {
1053 /* check the argument values */
1054 if (maxLength < 0 || maxRunCount < 0) {
1055 throw new IllegalArgumentException();
1056 }
1057
1058 /* reset the object, all reference variables null, all flags false,
1059 all sizes 0.
1060 In fact, we don't need to do anything, since class members are
1061 initialized as zero when an instance is created.
1062 */
1063 /*
1064 mayAllocateText = false;
1065 mayAllocateRuns = false;
1066 orderParagraphsLTR = false;
1067 paraCount = 0;
1068 runCount = 0;
1069 trailingWSStart = 0;
1070 flags = 0;
1071 paraLevel = 0;
1072 defaultParaLevel = 0;
1073 direction = 0;
1074 */
1075 /* get Bidi properties */
1076 try {
1077 bdp = UBiDiProps.getSingleton();
1078 }
1079 catch (IOException e) {
1080 throw new MissingResourceException(e.getMessage(), "(BidiProps)", "");
1081 }
1082
1083 /* allocate memory for arrays as requested */
1084 if (maxLength > 0) {
1085 getInitialDirPropsMemory(maxLength);
1086 getInitialLevelsMemory(maxLength);
1087 } else {
1088 mayAllocateText = true;
1089 }
1090
1091 if (maxRunCount > 0) {
1092 // if maxRunCount == 1, use simpleRuns[]
1093 if (maxRunCount > 1) {
1094 getInitialRunsMemory(maxRunCount);
1095 }
1096 } else {
1097 mayAllocateRuns = true;
1098 }
1099 }
1100
1101 /*
1102 * We are allowed to allocate memory if object==null or
1103 * mayAllocate==true for each array that we need.
1104 *
1105 * Assume sizeNeeded>0.
1106 * If object != null, then assume size > 0.
1107 */
1108 private Object getMemory(String label, Object array, Class<?> arrayClass,
1109 boolean mayAllocate, int sizeNeeded)
1110 {
1111 int len = Array.getLength(array);
1112
1113 /* we have at least enough memory and must not allocate */
1114 if (sizeNeeded == len) {
1115 return array;
1116 }
1117 if (!mayAllocate) {
1118 /* we must not allocate */
1119 if (sizeNeeded <= len) {
1120 return array;
1121 }
1122 throw new OutOfMemoryError("Failed to allocate memory for "
1123 + label);
1124 }
1125 /* we may try to grow or shrink */
1126 /* FOOD FOR THOUGHT: when shrinking it should be possible to avoid
1127 the allocation altogether and rely on this.length */
1128 try {
1129 return Array.newInstance(arrayClass, sizeNeeded);
1130 } catch (Exception e) {
1131 throw new OutOfMemoryError("Failed to allocate memory for "
1132 + label);
1133 }
1134 }
1135
1136 /* helper methods for each allocated array */
1137 private void getDirPropsMemory(boolean mayAllocate, int len)
1138 {
1139 Object array = getMemory("DirProps", dirPropsMemory, Byte.TYPE, mayAllocate, len);
1140 dirPropsMemory = (byte[]) array;
1141 }
1142
1143 void getDirPropsMemory(int len)
1144 {
1145 getDirPropsMemory(mayAllocateText, len);
1146 }
1147
1148 private void getLevelsMemory(boolean mayAllocate, int len)
1149 {
1150 Object array = getMemory("Levels", levelsMemory, Byte.TYPE, mayAllocate, len);
1151 levelsMemory = (byte[]) array;
1152 }
1153
1154 void getLevelsMemory(int len)
1155 {
1156 getLevelsMemory(mayAllocateText, len);
1157 }
1158
1159 private void getRunsMemory(boolean mayAllocate, int len)
1160 {
1161 Object array = getMemory("Runs", runsMemory, BidiRun.class, mayAllocate, len);
1162 runsMemory = (BidiRun[]) array;
1163 }
1164
1165 void getRunsMemory(int len)
1166 {
1167 getRunsMemory(mayAllocateRuns, len);
1168 }
1169
1170 /* additional methods used by constructor - always allow allocation */
1171 private void getInitialDirPropsMemory(int len)
1172 {
1173 getDirPropsMemory(true, len);
1174 }
1175
1176 private void getInitialLevelsMemory(int len)
1177 {
1178 getLevelsMemory(true, len);
1179 }
1180
1181 private void getInitialParasMemory(int len)
1182 {
1183 Object array = getMemory("Paras", parasMemory, Integer.TYPE, true, len);
1184 parasMemory = (int[]) array;
1185 }
1186
1187 private void getInitialRunsMemory(int len)
1188 {
1189 getRunsMemory(true, len);
1190 }
1191
1192 /* perform (P2)..(P3) ------------------------------------------------------- */
1193
1194 private void getDirProps()
1195 {
1196 int i = 0, i0, i1;
1197 flags = 0; /* collect all directionalities in the text */
1198 int uchar;
1199 byte dirProp;
1200 byte paraDirDefault = 0; /* initialize to avoid compiler warnings */
1201 boolean isDefaultLevel = IsDefaultLevel(paraLevel);
1202 /* for inverse Bidi, the default para level is set to RTL if there is a
1203 strong R or AL character at either end of the text */
1204 lastArabicPos = -1;
1205 controlCount = 0;
1206
1207 final int NOT_CONTEXTUAL = 0; /* 0: not contextual paraLevel */
1208 final int LOOKING_FOR_STRONG = 1; /* 1: looking for first strong char */
1209 final int FOUND_STRONG_CHAR = 2; /* 2: found first strong char */
1210
1211 int state;
1212 int paraStart = 0; /* index of first char in paragraph */
1213 byte paraDir; /* == CONTEXT_RTL within paragraphs
1214 starting with strong R char */
1215 byte lastStrongDir=0; /* for default level & inverse Bidi */
1216 int lastStrongLTR=0; /* for STREAMING option */
1217
1218 if (isDefaultLevel) {
1219 paraDirDefault = ((paraLevel & 1) != 0) ? CONTEXT_RTL : 0;
1220 paraDir = paraDirDefault;
1221 lastStrongDir = paraDirDefault;
1222 state = LOOKING_FOR_STRONG;
1223 } else {
1224 state = NOT_CONTEXTUAL;
1225 paraDir = 0;
1226 }
1227 /* count paragraphs and determine the paragraph level (P2..P3) */
1228 /*
1229 * see comment on constant fields:
1230 * the LEVEL_DEFAULT_XXX values are designed so that
1231 * their low-order bit alone yields the intended default
1232 */
1233
1234 for (i = 0; i < originalLength; /* i is incremented in the loop */) {
1235 i0 = i; /* index of first code unit */
1236 uchar = UTF16.charAt(text, 0, originalLength, i);
1237 i += Character.charCount(uchar);
1238 i1 = i - 1; /* index of last code unit, gets the directional property */
1239
1240 dirProp = (byte)bdp.getClass(uchar);
1241
1242 flags |= DirPropFlag(dirProp);
1243 dirProps[i1] = (byte)(dirProp | paraDir);
1244 if (i1 > i0) { /* set previous code units' properties to BN */
1245 flags |= DirPropFlag(BN);
1246 do {
1247 dirProps[--i1] = (byte)(BN | paraDir);
1248 } while (i1 > i0);
1249 }
1250 if (state == LOOKING_FOR_STRONG) {
1251 if (dirProp == L) {
1252 state = FOUND_STRONG_CHAR;
1253 if (paraDir != 0) {
1254 paraDir = 0;
1255 for (i1 = paraStart; i1 < i; i1++) {
1256 dirProps[i1] &= ~CONTEXT_RTL;
1257 }
1258 }
1259 continue;
1260 }
1261 if (dirProp == R || dirProp == AL) {
1262 state = FOUND_STRONG_CHAR;
1263 if (paraDir == 0) {
1264 paraDir = CONTEXT_RTL;
1265 for (i1 = paraStart; i1 < i; i1++) {
1266 dirProps[i1] |= CONTEXT_RTL;
1267 }
1268 }
1269 continue;
1270 }
1271 }
1272 if (dirProp == L) {
1273 lastStrongDir = 0;
1274 lastStrongLTR = i; /* i is index to next character */
1275 }
1276 else if (dirProp == R) {
1277 lastStrongDir = CONTEXT_RTL;
1278 }
1279 else if (dirProp == AL) {
1280 lastStrongDir = CONTEXT_RTL;
1281 lastArabicPos = i-1;
1282 }
1283 else if (dirProp == B) {
1284 if (i < originalLength) { /* B not last char in text */
1285 if (!((uchar == (int)CR) && (text[i] == (int)LF))) {
1286 paraCount++;
1287 }
1288 if (isDefaultLevel) {
1289 state=LOOKING_FOR_STRONG;
1290 paraStart = i; /* i is index to next character */
1291 paraDir = paraDirDefault;
1292 lastStrongDir = paraDirDefault;
1293 }
1294 }
1295 }
1296 }
1297 if (isDefaultLevel) {
1298 paraLevel = GetParaLevelAt(0);
1299 }
1300
1301 /* The following line does nothing new for contextual paraLevel, but is
1302 needed for absolute paraLevel. */
1303 flags |= DirPropFlagLR(paraLevel);
1304
1305 if (orderParagraphsLTR && (flags & DirPropFlag(B)) != 0) {
1306 flags |= DirPropFlag(L);
1307 }
1308 }
1309
1310 /* perform (X1)..(X9) ------------------------------------------------------- */
1311
1312 /* determine if the text is mixed-directional or single-directional */
1313 private byte directionFromFlags() {
1314 /* if the text contains AN and neutrals, then some neutrals may become RTL */
1315 if (!((flags & MASK_RTL) != 0 ||
1316 ((flags & DirPropFlag(AN)) != 0 &&
1317 (flags & MASK_POSSIBLE_N) != 0))) {
1318 return Bidi.DIRECTION_LEFT_TO_RIGHT;
1319 } else if ((flags & MASK_LTR) == 0) {
1320 return Bidi.DIRECTION_RIGHT_TO_LEFT;
1321 } else {
1322 return MIXED;
1323 }
1324 }
1325
1326 /*
1327 * Resolve the explicit levels as specified by explicit embedding codes.
1328 * Recalculate the flags to have them reflect the real properties
1329 * after taking the explicit embeddings into account.
1330 *
1331 * The Bidi algorithm is designed to result in the same behavior whether embedding
1332 * levels are externally specified (from "styled text", supposedly the preferred
1333 * method) or set by explicit embedding codes (LRx, RLx, PDF) in the plain text.
1334 * That is why (X9) instructs to remove all explicit codes (and BN).
1335 * However, in a real implementation, this removal of these codes and their index
1336 * positions in the plain text is undesirable since it would result in
1337 * reallocated, reindexed text.
1338 * Instead, this implementation leaves the codes in there and just ignores them
1339 * in the subsequent processing.
1340 * In order to get the same reordering behavior, positions with a BN or an
1341 * explicit embedding code just get the same level assigned as the last "real"
1342 * character.
1343 *
1344 * Some implementations, not this one, then overwrite some of these
1345 * directionality properties at "real" same-level-run boundaries by
1346 * L or R codes so that the resolution of weak types can be performed on the
1347 * entire paragraph at once instead of having to parse it once more and
1348 * perform that resolution on same-level-runs.
1349 * This limits the scope of the implicit rules in effectively
1350 * the same way as the run limits.
1351 *
1352 * Instead, this implementation does not modify these codes.
1353 * On one hand, the paragraph has to be scanned for same-level-runs, but
1354 * on the other hand, this saves another loop to reset these codes,
1355 * or saves making and modifying a copy of dirProps[].
1356 *
1357 *
1358 * Note that (Pn) and (Xn) changed significantly from version 4 of the Bidi algorithm.
1359 *
1360 *
1361 * Handling the stack of explicit levels (Xn):
1362 *
1363 * With the Bidi stack of explicit levels,
1364 * as pushed with each LRE, RLE, LRO, and RLO and popped with each PDF,
1365 * the explicit level must never exceed MAX_EXPLICIT_LEVEL==61.
1366 *
1367 * In order to have a correct push-pop semantics even in the case of overflows,
1368 * there are two overflow counters:
1369 * - countOver60 is incremented with each LRx at level 60
1370 * - from level 60, one RLx increases the level to 61
1371 * - countOver61 is incremented with each LRx and RLx at level 61
1372 *
1373 * Popping levels with PDF must work in the opposite order so that level 61
1374 * is correct at the correct point. Underflows (too many PDFs) must be checked.
1375 *
1376 * This implementation assumes that MAX_EXPLICIT_LEVEL is odd.
1377 */
1378 private byte resolveExplicitLevels() {
1379 int i = 0;
1380 byte dirProp;
1381 byte level = GetParaLevelAt(0);
1382
1383 byte dirct;
1384 int paraIndex = 0;
1385
1386 /* determine if the text is mixed-directional or single-directional */
1387 dirct = directionFromFlags();
1388
1389 /* we may not need to resolve any explicit levels, but for multiple
1390 paragraphs we want to loop on all chars to set the para boundaries */
1391 if ((dirct != MIXED) && (paraCount == 1)) {
1392 /* not mixed directionality: levels don't matter - trailingWSStart will be 0 */
1393 } else if ((paraCount == 1) &&
1394 ((flags & MASK_EXPLICIT) == 0)) {
1395 /* mixed, but all characters are at the same embedding level */
1396 /* or we are in "inverse Bidi" */
1397 /* and we don't have contextual multiple paragraphs with some B char */
1398 /* set all levels to the paragraph level */
1399 for (i = 0; i < length; ++i) {
1400 levels[i] = level;
1401 }
1402 } else {
1403 /* continue to perform (Xn) */
1404
1405 /* (X1) level is set for all codes, embeddingLevel keeps track of the push/pop operations */
1406 /* both variables may carry the LEVEL_OVERRIDE flag to indicate the override status */
1407 byte embeddingLevel = level;
1408 byte newLevel;
1409 byte stackTop = 0;
1410
1411 byte[] stack = new byte[MAX_EXPLICIT_LEVEL]; /* we never push anything >=MAX_EXPLICIT_LEVEL */
1412 int countOver60 = 0;
1413 int countOver61 = 0; /* count overflows of explicit levels */
1414
1415 /* recalculate the flags */
1416 flags = 0;
1417
1418 for (i = 0; i < length; ++i) {
1419 dirProp = NoContextRTL(dirProps[i]);
1420 switch(dirProp) {
1421 case LRE:
1422 case LRO:
1423 /* (X3, X5) */
1424 newLevel = (byte)((embeddingLevel+2) & ~(INTERNAL_LEVEL_OVERRIDE | 1)); /* least greater even level */
1425 if (newLevel <= MAX_EXPLICIT_LEVEL) {
1426 stack[stackTop] = embeddingLevel;
1427 ++stackTop;
1428 embeddingLevel = newLevel;
1429 if (dirProp == LRO) {
1430 embeddingLevel |= INTERNAL_LEVEL_OVERRIDE;
1431 }
1432 /* we don't need to set LEVEL_OVERRIDE off for LRE
1433 since this has already been done for newLevel which is
1434 the source for embeddingLevel.
1435 */
1436 } else if ((embeddingLevel & ~INTERNAL_LEVEL_OVERRIDE) == MAX_EXPLICIT_LEVEL) {
1437 ++countOver61;
1438 } else /* (embeddingLevel & ~INTERNAL_LEVEL_OVERRIDE) == MAX_EXPLICIT_LEVEL-1 */ {
1439 ++countOver60;
1440 }
1441 flags |= DirPropFlag(BN);
1442 break;
1443 case RLE:
1444 case RLO:
1445 /* (X2, X4) */
1446 newLevel=(byte)(((embeddingLevel & ~INTERNAL_LEVEL_OVERRIDE) + 1) | 1); /* least greater odd level */
1447 if (newLevel<=MAX_EXPLICIT_LEVEL) {
1448 stack[stackTop] = embeddingLevel;
1449 ++stackTop;
1450 embeddingLevel = newLevel;
1451 if (dirProp == RLO) {
1452 embeddingLevel |= INTERNAL_LEVEL_OVERRIDE;
1453 }
1454 /* we don't need to set LEVEL_OVERRIDE off for RLE
1455 since this has already been done for newLevel which is
1456 the source for embeddingLevel.
1457 */
1458 } else {
1459 ++countOver61;
1460 }
1461 flags |= DirPropFlag(BN);
1462 break;
1463 case PDF:
1464 /* (X7) */
1465 /* handle all the overflow cases first */
1466 if (countOver61 > 0) {
1467 --countOver61;
1468 } else if (countOver60 > 0 && (embeddingLevel & ~INTERNAL_LEVEL_OVERRIDE) != MAX_EXPLICIT_LEVEL) {
1469 /* handle LRx overflows from level 60 */
1470 --countOver60;
1471 } else if (stackTop > 0) {
1472 /* this is the pop operation; it also pops level 61 while countOver60>0 */
1473 --stackTop;
1474 embeddingLevel = stack[stackTop];
1475 /* } else { (underflow) */
1476 }
1477 flags |= DirPropFlag(BN);
1478 break;
1479 case B:
1480 stackTop = 0;
1481 countOver60 = 0;
1482 countOver61 = 0;
1483 level = GetParaLevelAt(i);
1484 if ((i + 1) < length) {
1485 embeddingLevel = GetParaLevelAt(i+1);
1486 if (!((text[i] == CR) && (text[i + 1] == LF))) {
1487 paras[paraIndex++] = i+1;
1488 }
1489 }
1490 flags |= DirPropFlag(B);
1491 break;
1492 case BN:
1493 /* BN, LRE, RLE, and PDF are supposed to be removed (X9) */
1494 /* they will get their levels set correctly in adjustWSLevels() */
1495 flags |= DirPropFlag(BN);
1496 break;
1497 default:
1498 /* all other types get the "real" level */
1499 if (level != embeddingLevel) {
1500 level = embeddingLevel;
1501 if ((level & INTERNAL_LEVEL_OVERRIDE) != 0) {
1502 flags |= DirPropFlagO(level) | DirPropFlagMultiRuns;
1503 } else {
1504 flags |= DirPropFlagE(level) | DirPropFlagMultiRuns;
1505 }
1506 }
1507 if ((level & INTERNAL_LEVEL_OVERRIDE) == 0) {
1508 flags |= DirPropFlag(dirProp);
1509 }
1510 break;
1511 }
1512
1513 /*
1514 * We need to set reasonable levels even on BN codes and
1515 * explicit codes because we will later look at same-level runs (X10).
1516 */
1517 levels[i] = level;
1518 }
1519 if ((flags & MASK_EMBEDDING) != 0) {
1520 flags |= DirPropFlagLR(paraLevel);
1521 }
1522 if (orderParagraphsLTR && (flags & DirPropFlag(B)) != 0) {
1523 flags |= DirPropFlag(L);
1524 }
1525
1526 /* subsequently, ignore the explicit codes and BN (X9) */
1527
1528 /* again, determine if the text is mixed-directional or single-directional */
1529 dirct = directionFromFlags();
1530 }
1531
1532 return dirct;
1533 }
1534
1535 /*
1536 * Use a pre-specified embedding levels array:
1537 *
1538 * Adjust the directional properties for overrides (->LEVEL_OVERRIDE),
1539 * ignore all explicit codes (X9),
1540 * and check all the preset levels.
1541 *
1542 * Recalculate the flags to have them reflect the real properties
1543 * after taking the explicit embeddings into account.
1544 */
1545 private byte checkExplicitLevels() {
1546 byte dirProp;
1547 int i;
1548 this.flags = 0; /* collect all directionalities in the text */
1549 byte level;
1550 int paraIndex = 0;
1551
1552 for (i = 0; i < length; ++i) {
1553 if (levels[i] == 0) {
1554 levels[i] = paraLevel;
1555 }
1556 if (MAX_EXPLICIT_LEVEL < (levels[i]&0x7f)) {
1557 if ((levels[i] & INTERNAL_LEVEL_OVERRIDE) != 0) {
1558 levels[i] = (byte)(paraLevel|INTERNAL_LEVEL_OVERRIDE);
1559 } else {
1560 levels[i] = paraLevel;
1561 }
1562 }
1563 level = levels[i];
1564 dirProp = NoContextRTL(dirProps[i]);
1565 if ((level & INTERNAL_LEVEL_OVERRIDE) != 0) {
1566 /* keep the override flag in levels[i] but adjust the flags */
1567 level &= ~INTERNAL_LEVEL_OVERRIDE; /* make the range check below simpler */
1568 flags |= DirPropFlagO(level);
1569 } else {
1570 /* set the flags */
1571 flags |= DirPropFlagE(level) | DirPropFlag(dirProp);
1572 }
1573
1574 if ((level < GetParaLevelAt(i) &&
1575 !((0 == level) && (dirProp == B))) ||
1576 (MAX_EXPLICIT_LEVEL <level)) {
1577 /* level out of bounds */
1578 throw new IllegalArgumentException("level " + level +
1579 " out of bounds at index " + i);
1580 }
1581 if ((dirProp == B) && ((i + 1) < length)) {
1582 if (!((text[i] == CR) && (text[i + 1] == LF))) {
1583 paras[paraIndex++] = i + 1;
1584 }
1585 }
1586 }
1587 if ((flags&MASK_EMBEDDING) != 0) {
1588 flags |= DirPropFlagLR(paraLevel);
1589 }
1590
1591 /* determine if the text is mixed-directional or single-directional */
1592 return directionFromFlags();
1593 }
1594
1595 /*********************************************************************/
1596 /* The Properties state machine table */
1597 /*********************************************************************/
1598 /* */
1599 /* All table cells are 8 bits: */
1600 /* bits 0..4: next state */
1601 /* bits 5..7: action to perform (if > 0) */
1602 /* */
1603 /* Cells may be of format "n" where n represents the next state */
1604 /* (except for the rightmost column). */
1605 /* Cells may also be of format "_(x,y)" where x represents an action */
1606 /* to perform and y represents the next state. */
1607 /* */
1608 /*********************************************************************/
1609 /* Definitions and type for properties state tables */
1610 /*********************************************************************/
1611 private static final int IMPTABPROPS_COLUMNS = 14;
1612 private static final int IMPTABPROPS_RES = IMPTABPROPS_COLUMNS - 1;
1613 private static short GetStateProps(short cell) {
1614 return (short)(cell & 0x1f);
1615 }
1616 private static short GetActionProps(short cell) {
1617 return (short)(cell >> 5);
1618 }
1619
1620 private static final short groupProp[] = /* dirProp regrouped */
1621 {
1622 /* L R EN ES ET AN CS B S WS ON LRE LRO AL RLE RLO PDF NSM BN */
1623 0, 1, 2, 7, 8, 3, 9, 6, 5, 4, 4, 10, 10, 12, 10, 10, 10, 11, 10
1624 };
1625 private static final short _L = 0;
1626 private static final short _R = 1;
1627 private static final short _EN = 2;
1628 private static final short _AN = 3;
1629 private static final short _ON = 4;
1630 private static final short _S = 5;
1631 private static final short _B = 6; /* reduced dirProp */
1632
1633 /*********************************************************************/
1634 /* */
1635 /* PROPERTIES STATE TABLE */
1636 /* */
1637 /* In table impTabProps, */
1638 /* - the ON column regroups ON and WS */
1639 /* - the BN column regroups BN, LRE, RLE, LRO, RLO, PDF */
1640 /* - the Res column is the reduced property assigned to a run */
1641 /* */
1642 /* Action 1: process current run1, init new run1 */
1643 /* 2: init new run2 */
1644 /* 3: process run1, process run2, init new run1 */
1645 /* 4: process run1, set run1=run2, init new run2 */
1646 /* */
1647 /* Notes: */
1648 /* 1) This table is used in resolveImplicitLevels(). */
1649 /* 2) This table triggers actions when there is a change in the Bidi*/
1650 /* property of incoming characters (action 1). */
1651 /* 3) Most such property sequences are processed immediately (in */
1652 /* fact, passed to processPropertySeq(). */
1653 /* 4) However, numbers are assembled as one sequence. This means */
1654 /* that undefined situations (like CS following digits, until */
1655 /* it is known if the next char will be a digit) are held until */
1656 /* following chars define them. */
1657 /* Example: digits followed by CS, then comes another CS or ON; */
1658 /* the digits will be processed, then the CS assigned */
1659 /* as the start of an ON sequence (action 3). */
1660 /* 5) There are cases where more than one sequence must be */
1661 /* processed, for instance digits followed by CS followed by L: */
1662 /* the digits must be processed as one sequence, and the CS */
1663 /* must be processed as an ON sequence, all this before starting */
1664 /* assembling chars for the opening L sequence. */
1665 /* */
1666 /* */
1667 private static final short impTabProps[][] =
1668 {
1669 /* L, R, EN, AN, ON, S, B, ES, ET, CS, BN, NSM, AL, Res */
1670 /* 0 Init */ { 1, 2, 4, 5, 7, 15, 17, 7, 9, 7, 0, 7, 3, _ON },
1671 /* 1 L */ { 1, 32+2, 32+4, 32+5, 32+7, 32+15, 32+17, 32+7, 32+9, 32+7, 1, 1, 32+3, _L },
1672 /* 2 R */ { 32+1, 2, 32+4, 32+5, 32+7, 32+15, 32+17, 32+7, 32+9, 32+7, 2, 2, 32+3, _R },
1673 /* 3 AL */ { 32+1, 32+2, 32+6, 32+6, 32+8, 32+16, 32+17, 32+8, 32+8, 32+8, 3, 3, 3, _R },
1674 /* 4 EN */ { 32+1, 32+2, 4, 32+5, 32+7, 32+15, 32+17, 64+10, 11, 64+10, 4, 4, 32+3, _EN },
1675 /* 5 AN */ { 32+1, 32+2, 32+4, 5, 32+7, 32+15, 32+17, 32+7, 32+9, 64+12, 5, 5, 32+3, _AN },
1676 /* 6 AL:EN/AN */ { 32+1, 32+2, 6, 6, 32+8, 32+16, 32+17, 32+8, 32+8, 64+13, 6, 6, 32+3, _AN },
1677 /* 7 ON */ { 32+1, 32+2, 32+4, 32+5, 7, 32+15, 32+17, 7, 64+14, 7, 7, 7, 32+3, _ON },
1678 /* 8 AL:ON */ { 32+1, 32+2, 32+6, 32+6, 8, 32+16, 32+17, 8, 8, 8, 8, 8, 32+3, _ON },
1679 /* 9 ET */ { 32+1, 32+2, 4, 32+5, 7, 32+15, 32+17, 7, 9, 7, 9, 9, 32+3, _ON },
1680 /*10 EN+ES/CS */ { 96+1, 96+2, 4, 96+5, 128+7, 96+15, 96+17, 128+7,128+14, 128+7, 10, 128+7, 96+3, _EN },
1681 /*11 EN+ET */ { 32+1, 32+2, 4, 32+5, 32+7, 32+15, 32+17, 32+7, 11, 32+7, 11, 11, 32+3, _EN },
1682 /*12 AN+CS */ { 96+1, 96+2, 96+4, 5, 128+7, 96+15, 96+17, 128+7,128+14, 128+7, 12, 128+7, 96+3, _AN },
1683 /*13 AL:EN/AN+CS */ { 96+1, 96+2, 6, 6, 128+8, 96+16, 96+17, 128+8, 128+8, 128+8, 13, 128+8, 96+3, _AN },
1684 /*14 ON+ET */ { 32+1, 32+2, 128+4, 32+5, 7, 32+15, 32+17, 7, 14, 7, 14, 14, 32+3, _ON },
1685 /*15 S */ { 32+1, 32+2, 32+4, 32+5, 32+7, 15, 32+17, 32+7, 32+9, 32+7, 15, 32+7, 32+3, _S },
1686 /*16 AL:S */ { 32+1, 32+2, 32+6, 32+6, 32+8, 16, 32+17, 32+8, 32+8, 32+8, 16, 32+8, 32+3, _S },
1687 /*17 B */ { 32+1, 32+2, 32+4, 32+5, 32+7, 32+15, 17, 32+7, 32+9, 32+7, 17, 32+7, 32+3, _B }
1688 };
1689
1690 /*********************************************************************/
1691 /* The levels state machine tables */
1692 /*********************************************************************/
1693 /* */
1694 /* All table cells are 8 bits: */
1695 /* bits 0..3: next state */
1696 /* bits 4..7: action to perform (if > 0) */
1697 /* */
1698 /* Cells may be of format "n" where n represents the next state */
1699 /* (except for the rightmost column). */
1700 /* Cells may also be of format "_(x,y)" where x represents an action */
1701 /* to perform and y represents the next state. */
1702 /* */
1703 /* This format limits each table to 16 states each and to 15 actions.*/
1704 /* */
1705 /*********************************************************************/
1706 /* Definitions and type for levels state tables */
1707 /*********************************************************************/
1708 private static final int IMPTABLEVELS_COLUMNS = _B + 2;
1709 private static final int IMPTABLEVELS_RES = IMPTABLEVELS_COLUMNS - 1;
1710 private static short GetState(byte cell) { return (short)(cell & 0x0f); }
1711 private static short GetAction(byte cell) { return (short)(cell >> 4); }
1712
1713 private static class ImpTabPair {
1714 byte[][][] imptab;
1715 short[][] impact;
1716
1717 ImpTabPair(byte[][] table1, byte[][] table2,
1718 short[] act1, short[] act2) {
1719 imptab = new byte[][][] {table1, table2};
1720 impact = new short[][] {act1, act2};
1721 }
1722 }
1723
1724 /*********************************************************************/
1725 /* */
1726 /* LEVELS STATE TABLES */
1727 /* */
1728 /* In all levels state tables, */
1729 /* - state 0 is the initial state */
1730 /* - the Res column is the increment to add to the text level */
1731 /* for this property sequence. */
1732 /* */
1733 /* The impact arrays for each table of a pair map the local action */
1734 /* numbers of the table to the total list of actions. For instance, */
1735 /* action 2 in a given table corresponds to the action number which */
1736 /* appears in entry [2] of the impact array for that table. */
1737 /* The first entry of all impact arrays must be 0. */
1738 /* */
1739 /* Action 1: init conditional sequence */
1740 /* 2: prepend conditional sequence to current sequence */
1741 /* 3: set ON sequence to new level - 1 */
1742 /* 4: init EN/AN/ON sequence */
1743 /* 5: fix EN/AN/ON sequence followed by R */
1744 /* 6: set previous level sequence to level 2 */
1745 /* */
1746 /* Notes: */
1747 /* 1) These tables are used in processPropertySeq(). The input */
1748 /* is property sequences as determined by resolveImplicitLevels. */
1749 /* 2) Most such property sequences are processed immediately */
1750 /* (levels are assigned). */
1751 /* 3) However, some sequences cannot be assigned a final level till */
1752 /* one or more following sequences are received. For instance, */
1753 /* ON following an R sequence within an even-level paragraph. */
1754 /* If the following sequence is R, the ON sequence will be */
1755 /* assigned basic run level+1, and so will the R sequence. */
1756 /* 4) S is generally handled like ON, since its level will be fixed */
1757 /* to paragraph level in adjustWSLevels(). */
1758 /* */
1759
1760 private static final byte impTabL_DEFAULT[][] = /* Even paragraph level */
1761 /* In this table, conditional sequences receive the higher possible level
1762 until proven otherwise.
1763 */
1764 {
1765 /* L, R, EN, AN, ON, S, B, Res */
1766 /* 0 : init */ { 0, 1, 0, 2, 0, 0, 0, 0 },
1767 /* 1 : R */ { 0, 1, 3, 3, 0x14, 0x14, 0, 1 },
1768 /* 2 : AN */ { 0, 1, 0, 2, 0x15, 0x15, 0, 2 },
1769 /* 3 : R+EN/AN */ { 0, 1, 3, 3, 0x14, 0x14, 0, 2 },
1770 /* 4 : R+ON */ { 0x20, 1, 3, 3, 4, 4, 0x20, 1 },
1771 /* 5 : AN+ON */ { 0x20, 1, 0x20, 2, 5, 5, 0x20, 1 }
1772 };
1773
1774 private static final byte impTabR_DEFAULT[][] = /* Odd paragraph level */
1775 /* In this table, conditional sequences receive the lower possible level
1776 until proven otherwise.
1777 */
1778 {
1779 /* L, R, EN, AN, ON, S, B, Res */
1780 /* 0 : init */ { 1, 0, 2, 2, 0, 0, 0, 0 },
1781 /* 1 : L */ { 1, 0, 1, 3, 0x14, 0x14, 0, 1 },
1782 /* 2 : EN/AN */ { 1, 0, 2, 2, 0, 0, 0, 1 },
1783 /* 3 : L+AN */ { 1, 0, 1, 3, 5, 5, 0, 1 },
1784 /* 4 : L+ON */ { 0x21, 0, 0x21, 3, 4, 4, 0, 0 },
1785 /* 5 : L+AN+ON */ { 1, 0, 1, 3, 5, 5, 0, 0 }
1786 };
1787
1788 private static final short[] impAct0 = {0,1,2,3,4,5,6};
1789
1790 private static final ImpTabPair impTab_DEFAULT = new ImpTabPair(
1791 impTabL_DEFAULT, impTabR_DEFAULT, impAct0, impAct0);
1792
1793 private static final byte impTabL_NUMBERS_SPECIAL[][] = { /* Even paragraph level */
1794 /* In this table, conditional sequences receive the higher possible
1795 level until proven otherwise.
1796 */
1797 /* L, R, EN, AN, ON, S, B, Res */
1798 /* 0 : init */ { 0, 2, 1, 1, 0, 0, 0, 0 },
1799 /* 1 : L+EN/AN */ { 0, 2, 1, 1, 0, 0, 0, 2 },
1800 /* 2 : R */ { 0, 2, 4, 4, 0x13, 0, 0, 1 },
1801 /* 3 : R+ON */ { 0x20, 2, 4, 4, 3, 3, 0x20, 1 },
1802 /* 4 : R+EN/AN */ { 0, 2, 4, 4, 0x13, 0x13, 0, 2 }
1803 };
1804 private static final ImpTabPair impTab_NUMBERS_SPECIAL = new ImpTabPair(
1805 impTabL_NUMBERS_SPECIAL, impTabR_DEFAULT, impAct0, impAct0);
1806
1807 private static final byte impTabL_GROUP_NUMBERS_WITH_R[][] = {
1808 /* In this table, EN/AN+ON sequences receive levels as if associated with R
1809 until proven that there is L or sor/eor on both sides. AN is handled like EN.
1810 */
1811 /* L, R, EN, AN, ON, S, B, Res */
1812 /* 0 init */ { 0, 3, 0x11, 0x11, 0, 0, 0, 0 },
1813 /* 1 EN/AN */ { 0x20, 3, 1, 1, 2, 0x20, 0x20, 2 },
1814 /* 2 EN/AN+ON */ { 0x20, 3, 1, 1, 2, 0x20, 0x20, 1 },
1815 /* 3 R */ { 0, 3, 5, 5, 0x14, 0, 0, 1 },
1816 /* 4 R+ON */ { 0x20, 3, 5, 5, 4, 0x20, 0x20, 1 },
1817 /* 5 R+EN/AN */ { 0, 3, 5, 5, 0x14, 0, 0, 2 }
1818 };
1819 private static final byte impTabR_GROUP_NUMBERS_WITH_R[][] = {
1820 /* In this table, EN/AN+ON sequences receive levels as if associated with R
1821 until proven that there is L on both sides. AN is handled like EN.
1822 */
1823 /* L, R, EN, AN, ON, S, B, Res */
1824 /* 0 init */ { 2, 0, 1, 1, 0, 0, 0, 0 },
1825 /* 1 EN/AN */ { 2, 0, 1, 1, 0, 0, 0, 1 },
1826 /* 2 L */ { 2, 0, 0x14, 0x14, 0x13, 0, 0, 1 },
1827 /* 3 L+ON */ { 0x22, 0, 4, 4, 3, 0, 0, 0 },
1828 /* 4 L+EN/AN */ { 0x22, 0, 4, 4, 3, 0, 0, 1 }
1829 };
1830 private static final ImpTabPair impTab_GROUP_NUMBERS_WITH_R = new
1831 ImpTabPair(impTabL_GROUP_NUMBERS_WITH_R,
1832 impTabR_GROUP_NUMBERS_WITH_R, impAct0, impAct0);
1833
1834 private static final byte impTabL_INVERSE_NUMBERS_AS_L[][] = {
1835 /* This table is identical to the Default LTR table except that EN and AN
1836 are handled like L.
1837 */
1838 /* L, R, EN, AN, ON, S, B, Res */
1839 /* 0 : init */ { 0, 1, 0, 0, 0, 0, 0, 0 },
1840 /* 1 : R */ { 0, 1, 0, 0, 0x14, 0x14, 0, 1 },
1841 /* 2 : AN */ { 0, 1, 0, 0, 0x15, 0x15, 0, 2 },
1842 /* 3 : R+EN/AN */ { 0, 1, 0, 0, 0x14, 0x14, 0, 2 },
1843 /* 4 : R+ON */ { 0x20, 1, 0x20, 0x20, 4, 4, 0x20, 1 },
1844 /* 5 : AN+ON */ { 0x20, 1, 0x20, 0x20, 5, 5, 0x20, 1 }
1845 };
1846 private static final byte impTabR_INVERSE_NUMBERS_AS_L[][] = {
1847 /* This table is identical to the Default RTL table except that EN and AN
1848 are handled like L.
1849 */
1850 /* L, R, EN, AN, ON, S, B, Res */
1851 /* 0 : init */ { 1, 0, 1, 1, 0, 0, 0, 0 },
1852 /* 1 : L */ { 1, 0, 1, 1, 0x14, 0x14, 0, 1 },
1853 /* 2 : EN/AN */ { 1, 0, 1, 1, 0, 0, 0, 1 },
1854 /* 3 : L+AN */ { 1, 0, 1, 1, 5, 5, 0, 1 },
1855 /* 4 : L+ON */ { 0x21, 0, 0x21, 0x21, 4, 4, 0, 0 },
1856 /* 5 : L+AN+ON */ { 1, 0, 1, 1, 5, 5, 0, 0 }
1857 };
1858 private static final ImpTabPair impTab_INVERSE_NUMBERS_AS_L = new ImpTabPair
1859 (impTabL_INVERSE_NUMBERS_AS_L, impTabR_INVERSE_NUMBERS_AS_L,
1860 impAct0, impAct0);
1861
1862 private static final byte impTabR_INVERSE_LIKE_DIRECT[][] = { /* Odd paragraph level */
1863 /* In this table, conditional sequences receive the lower possible level
1864 until proven otherwise.
1865 */
1866 /* L, R, EN, AN, ON, S, B, Res */
1867 /* 0 : init */ { 1, 0, 2, 2, 0, 0, 0, 0 },
1868 /* 1 : L */ { 1, 0, 1, 2, 0x13, 0x13, 0, 1 },
1869 /* 2 : EN/AN */ { 1, 0, 2, 2, 0, 0, 0, 1 },
1870 /* 3 : L+ON */ { 0x21, 0x30, 6, 4, 3, 3, 0x30, 0 },
1871 /* 4 : L+ON+AN */ { 0x21, 0x30, 6, 4, 5, 5, 0x30, 3 },
1872 /* 5 : L+AN+ON */ { 0x21, 0x30, 6, 4, 5, 5, 0x30, 2 },
1873 /* 6 : L+ON+EN */ { 0x21, 0x30, 6, 4, 3, 3, 0x30, 1 }
1874 };
1875 private static final short[] impAct1 = {0,1,11,12};
1876 private static final ImpTabPair impTab_INVERSE_LIKE_DIRECT = new ImpTabPair(
1877 impTabL_DEFAULT, impTabR_INVERSE_LIKE_DIRECT, impAct0, impAct1);
1878
1879 private static final byte impTabL_INVERSE_LIKE_DIRECT_WITH_MARKS[][] = {
1880 /* The case handled in this table is (visually): R EN L
1881 */
1882 /* L, R, EN, AN, ON, S, B, Res */
1883 /* 0 : init */ { 0, 0x63, 0, 1, 0, 0, 0, 0 },
1884 /* 1 : L+AN */ { 0, 0x63, 0, 1, 0x12, 0x30, 0, 4 },
1885 /* 2 : L+AN+ON */ { 0x20, 0x63, 0x20, 1, 2, 0x30, 0x20, 3 },
1886 /* 3 : R */ { 0, 0x63, 0x55, 0x56, 0x14, 0x30, 0, 3 },
1887 /* 4 : R+ON */ { 0x30, 0x43, 0x55, 0x56, 4, 0x30, 0x30, 3 },
1888 /* 5 : R+EN */ { 0x30, 0x43, 5, 0x56, 0x14, 0x30, 0x30, 4 },
1889 /* 6 : R+AN */ { 0x30, 0x43, 0x55, 6, 0x14, 0x30, 0x30, 4 }
1890 };
1891 private static final byte impTabR_INVERSE_LIKE_DIRECT_WITH_MARKS[][] = {
1892 /* The cases handled in this table are (visually): R EN L
1893 R L AN L
1894 */
1895 /* L, R, EN, AN, ON, S, B, Res */
1896 /* 0 : init */ { 0x13, 0, 1, 1, 0, 0, 0, 0 },
1897 /* 1 : R+EN/AN */ { 0x23, 0, 1, 1, 2, 0x40, 0, 1 },
1898 /* 2 : R+EN/AN+ON */ { 0x23, 0, 1, 1, 2, 0x40, 0, 0 },
1899 /* 3 : L */ { 3 , 0, 3, 0x36, 0x14, 0x40, 0, 1 },
1900 /* 4 : L+ON */ { 0x53, 0x40, 5, 0x36, 4, 0x40, 0x40, 0 },
1901 /* 5 : L+ON+EN */ { 0x53, 0x40, 5, 0x36, 4, 0x40, 0x40, 1 },
1902 /* 6 : L+AN */ { 0x53, 0x40, 6, 6, 4, 0x40, 0x40, 3 }
1903 };
1904 private static final short impAct2[] = {0,1,7,8,9,10};
1905 private static final ImpTabPair impTab_INVERSE_LIKE_DIRECT_WITH_MARKS =
1906 new ImpTabPair(impTabL_INVERSE_LIKE_DIRECT_WITH_MARKS,
1907 impTabR_INVERSE_LIKE_DIRECT_WITH_MARKS, impAct0, impAct2);
1908
1909 private static final ImpTabPair impTab_INVERSE_FOR_NUMBERS_SPECIAL = new ImpTabPair(
1910 impTabL_NUMBERS_SPECIAL, impTabR_INVERSE_LIKE_DIRECT, impAct0, impAct1);
1911
1912 private static final byte impTabL_INVERSE_FOR_NUMBERS_SPECIAL_WITH_MARKS[][] = {
1913 /* The case handled in this table is (visually): R EN L
1914 */
1915 /* L, R, EN, AN, ON, S, B, Res */
1916 /* 0 : init */ { 0, 0x62, 1, 1, 0, 0, 0, 0 },
1917 /* 1 : L+EN/AN */ { 0, 0x62, 1, 1, 0, 0x30, 0, 4 },
1918 /* 2 : R */ { 0, 0x62, 0x54, 0x54, 0x13, 0x30, 0, 3 },
1919 /* 3 : R+ON */ { 0x30, 0x42, 0x54, 0x54, 3, 0x30, 0x30, 3 },
1920 /* 4 : R+EN/AN */ { 0x30, 0x42, 4, 4, 0x13, 0x30, 0x30, 4 }
1921 };
1922 private static final ImpTabPair impTab_INVERSE_FOR_NUMBERS_SPECIAL_WITH_MARKS = new
1923 ImpTabPair(impTabL_INVERSE_FOR_NUMBERS_SPECIAL_WITH_MARKS,
1924 impTabR_INVERSE_LIKE_DIRECT_WITH_MARKS, impAct0, impAct2);
1925
1926 private class LevState {
1927 byte[][] impTab; /* level table pointer */
1928 short[] impAct; /* action map array */
1929 int startON; /* start of ON sequence */
1930 int startL2EN; /* start of level 2 sequence */
1931 int lastStrongRTL; /* index of last found R or AL */
1932 short state; /* current state */
1933 byte runLevel; /* run level before implicit solving */
1934 }
1935
1936 /*------------------------------------------------------------------------*/
1937
1938 static final int FIRSTALLOC = 10;
1939 /*
1940 * param pos: position where to insert
1941 * param flag: one of LRM_BEFORE, LRM_AFTER, RLM_BEFORE, RLM_AFTER
1942 */
1943 private void addPoint(int pos, int flag)
1944 {
1945 Point point = new Point();
1946
1947 int len = insertPoints.points.length;
1948 if (len == 0) {
1949 insertPoints.points = new Point[FIRSTALLOC];
1950 len = FIRSTALLOC;
1951 }
1952 if (insertPoints.size >= len) { /* no room for new point */
1953 Point[] savePoints = insertPoints.points;
1954 insertPoints.points = new Point[len * 2];
1955 System.arraycopy(savePoints, 0, insertPoints.points, 0, len);
1956 }
1957 point.pos = pos;
1958 point.flag = flag;
1959 insertPoints.points[insertPoints.size] = point;
1960 insertPoints.size++;
1961 }
1962
1963 /* perform rules (Wn), (Nn), and (In) on a run of the text ------------------ */
1964
1965 /*
1966 * This implementation of the (Wn) rules applies all rules in one pass.
1967 * In order to do so, it needs a look-ahead of typically 1 character
1968 * (except for W5: sequences of ET) and keeps track of changes
1969 * in a rule Wp that affect a later Wq (p<q).
1970 *
1971 * The (Nn) and (In) rules are also performed in that same single loop,
1972 * but effectively one iteration behind for white space.
1973 *
1974 * Since all implicit rules are performed in one step, it is not necessary
1975 * to actually store the intermediate directional properties in dirProps[].
1976 */
1977
1978 private void processPropertySeq(LevState levState, short _prop,
1979 int start, int limit) {
1980 byte cell;
1981 byte[][] impTab = levState.impTab;
1982 short[] impAct = levState.impAct;
1983 short oldStateSeq,actionSeq;
1984 byte level, addLevel;
1985 int start0, k;
1986
1987 start0 = start; /* save original start position */
1988 oldStateSeq = levState.state;
1989 cell = impTab[oldStateSeq][_prop];
1990 levState.state = GetState(cell); /* isolate the new state */
1991 actionSeq = impAct[GetAction(cell)]; /* isolate the action */
1992 addLevel = impTab[levState.state][IMPTABLEVELS_RES];
1993
1994 if (actionSeq != 0) {
1995 switch (actionSeq) {
1996 case 1: /* init ON seq */
1997 levState.startON = start0;
1998 break;
1999
2000 case 2: /* prepend ON seq to current seq */
2001 start = levState.startON;
2002 break;
2003
2004 case 3: /* L or S after possible relevant EN/AN */
2005 /* check if we had EN after R/AL */
2006 if (levState.startL2EN >= 0) {
2007 addPoint(levState.startL2EN, LRM_BEFORE);
2008 }
2009 levState.startL2EN = -1; /* not within previous if since could also be -2 */
2010 /* check if we had any relevant EN/AN after R/AL */
2011 if ((insertPoints.points.length == 0) ||
2012 (insertPoints.size <= insertPoints.confirmed)) {
2013 /* nothing, just clean up */
2014 levState.lastStrongRTL = -1;
2015 /* check if we have a pending conditional segment */
2016 level = impTab[oldStateSeq][IMPTABLEVELS_RES];
2017 if ((level & 1) != 0 && levState.startON > 0) { /* after ON */
2018 start = levState.startON; /* reset to basic run level */
2019 }
2020 if (_prop == _S) { /* add LRM before S */
2021 addPoint(start0, LRM_BEFORE);
2022 insertPoints.confirmed = insertPoints.size;
2023 }
2024 break;
2025 }
2026 /* reset previous RTL cont to level for LTR text */
2027 for (k = levState.lastStrongRTL + 1; k < start0; k++) {
2028 /* reset odd level, leave runLevel+2 as is */
2029 levels[k] = (byte)((levels[k] - 2) & ~1);
2030 }
2031 /* mark insert points as confirmed */
2032 insertPoints.confirmed = insertPoints.size;
2033 levState.lastStrongRTL = -1;
2034 if (_prop == _S) { /* add LRM before S */
2035 addPoint(start0, LRM_BEFORE);
2036 insertPoints.confirmed = insertPoints.size;
2037 }
2038 break;
2039
2040 case 4: /* R/AL after possible relevant EN/AN */
2041 /* just clean up */
2042 if (insertPoints.points.length > 0)
2043 /* remove all non confirmed insert points */
2044 insertPoints.size = insertPoints.confirmed;
2045 levState.startON = -1;
2046 levState.startL2EN = -1;
2047 levState.lastStrongRTL = limit - 1;
2048 break;
2049
2050 case 5: /* EN/AN after R/AL + possible cont */
2051 /* check for real AN */
2052 if ((_prop == _AN) && (NoContextRTL(dirProps[start0]) == AN)) {
2053 /* real AN */
2054 if (levState.startL2EN == -1) { /* if no relevant EN already found */
2055 /* just note the righmost digit as a strong RTL */
2056 levState.lastStrongRTL = limit - 1;
2057 break;
2058 }
2059 if (levState.startL2EN >= 0) { /* after EN, no AN */
2060 addPoint(levState.startL2EN, LRM_BEFORE);
2061 levState.startL2EN = -2;
2062 }
2063 /* note AN */
2064 addPoint(start0, LRM_BEFORE);
2065 break;
2066 }
2067 /* if first EN/AN after R/AL */
2068 if (levState.startL2EN == -1) {
2069 levState.startL2EN = start0;
2070 }
2071 break;
2072
2073 case 6: /* note location of latest R/AL */
2074 levState.lastStrongRTL = limit - 1;
2075 levState.startON = -1;
2076 break;
2077
2078 case 7: /* L after R+ON/EN/AN */
2079 /* include possible adjacent number on the left */
2080 for (k = start0-1; k >= 0 && ((levels[k] & 1) == 0); k--) {
2081 }
2082 if (k >= 0) {
2083 addPoint(k, RLM_BEFORE); /* add RLM before */
2084 insertPoints.confirmed = insertPoints.size; /* confirm it */
2085 }
2086 levState.startON = start0;
2087 break;
2088
2089 case 8: /* AN after L */
2090 /* AN numbers between L text on both sides may be trouble. */
2091 /* tentatively bracket with LRMs; will be confirmed if followed by L */
2092 addPoint(start0, LRM_BEFORE); /* add LRM before */
2093 addPoint(start0, LRM_AFTER); /* add LRM after */
2094 break;
2095
2096 case 9: /* R after L+ON/EN/AN */
2097 /* false alert, infirm LRMs around previous AN */
2098 insertPoints.size=insertPoints.confirmed;
2099 if (_prop == _S) { /* add RLM before S */
2100 addPoint(start0, RLM_BEFORE);
2101 insertPoints.confirmed = insertPoints.size;
2102 }
2103 break;
2104
2105 case 10: /* L after L+ON/AN */
2106 level = (byte)(levState.runLevel + addLevel);
2107 for (k=levState.startON; k < start0; k++) {
2108 if (levels[k] < level) {
2109 levels[k] = level;
2110 }
2111 }
2112 insertPoints.confirmed = insertPoints.size; /* confirm inserts */
2113 levState.startON = start0;
2114 break;
2115
2116 case 11: /* L after L+ON+EN/AN/ON */
2117 level = levState.runLevel;
2118 for (k = start0-1; k >= levState.startON; k--) {
2119 if (levels[k] == level+3) {
2120 while (levels[k] == level+3) {
2121 levels[k--] -= 2;
2122 }
2123 while (levels[k] == level) {
2124 k--;
2125 }
2126 }
2127 if (levels[k] == level+2) {
2128 levels[k] = level;
2129 continue;
2130 }
2131 levels[k] = (byte)(level+1);
2132 }
2133 break;
2134
2135 case 12: /* R after L+ON+EN/AN/ON */
2136 level = (byte)(levState.runLevel+1);
2137 for (k = start0-1; k >= levState.startON; k--) {
2138 if (levels[k] > level) {
2139 levels[k] -= 2;
2140 }
2141 }
2142 break;
2143
2144 default: /* we should never get here */
2145 throw new IllegalStateException("Internal ICU error in processPropertySeq");
2146 }
2147 }
2148 if ((addLevel) != 0 || (start < start0)) {
2149 level = (byte)(levState.runLevel + addLevel);
2150 for (k = start; k < limit; k++) {
2151 levels[k] = level;
2152 }
2153 }
2154 }
2155
2156 private void resolveImplicitLevels(int start, int limit, short sor, short eor)
2157 {
2158 LevState levState = new LevState();
2159 int i, start1, start2;
2160 short oldStateImp, stateImp, actionImp;
2161 short gprop, resProp, cell;
2162 short nextStrongProp = R;
2163 int nextStrongPos = -1;
2164
2165
2166 /* check for RTL inverse Bidi mode */
2167 /* FOOD FOR THOUGHT: in case of RTL inverse Bidi, it would make sense to
2168 * loop on the text characters from end to start.
2169 * This would need a different properties state table (at least different
2170 * actions) and different levels state tables (maybe very similar to the
2171 * LTR corresponding ones.
2172 */
2173 /* initialize for levels state table */
2174 levState.startL2EN = -1; /* used for INVERSE_LIKE_DIRECT_WITH_MARKS */
2175 levState.lastStrongRTL = -1; /* used for INVERSE_LIKE_DIRECT_WITH_MARKS */
2176 levState.state = 0;
2177 levState.runLevel = levels[start];
2178 levState.impTab = impTabPair.imptab[levState.runLevel & 1];
2179 levState.impAct = impTabPair.impact[levState.runLevel & 1];
2180 processPropertySeq(levState, sor, start, start);
2181 /* initialize for property state table */
2182 if (dirProps[start] == NSM) {
2183 stateImp = (short)(1 + sor);
2184 } else {
2185 stateImp = 0;
2186 }
2187 start1 = start;
2188 start2 = 0;
2189
2190 for (i = start; i <= limit; i++) {
2191 if (i >= limit) {
2192 gprop = eor;
2193 } else {
2194 short prop, prop1;
2195 prop = NoContextRTL(dirProps[i]);
2196 gprop = groupProp[prop];
2197 }
2198 oldStateImp = stateImp;
2199 cell = impTabProps[oldStateImp][gprop];
2200 stateImp = GetStateProps(cell); /* isolate the new state */
2201 actionImp = GetActionProps(cell); /* isolate the action */
2202 if ((i == limit) && (actionImp == 0)) {
2203 /* there is an unprocessed sequence if its property == eor */
2204 actionImp = 1; /* process the last sequence */
2205 }
2206 if (actionImp != 0) {
2207 resProp = impTabProps[oldStateImp][IMPTABPROPS_RES];
2208 switch (actionImp) {
2209 case 1: /* process current seq1, init new seq1 */
2210 processPropertySeq(levState, resProp, start1, i);
2211 start1 = i;
2212 break;
2213 case 2: /* init new seq2 */
2214 start2 = i;
2215 break;
2216 case 3: /* process seq1, process seq2, init new seq1 */
2217 processPropertySeq(levState, resProp, start1, start2);
2218 processPropertySeq(levState, _ON, start2, i);
2219 start1 = i;
2220 break;
2221 case 4: /* process seq1, set seq1=seq2, init new seq2 */
2222 processPropertySeq(levState, resProp, start1, start2);
2223 start1 = start2;
2224 start2 = i;
2225 break;
2226 default: /* we should never get here */
2227 throw new IllegalStateException("Internal ICU error in resolveImplicitLevels");
2228 }
2229 }
2230 }
2231 /* flush possible pending sequence, e.g. ON */
2232 processPropertySeq(levState, eor, limit, limit);
2233 }
2234
2235 /* perform (L1) and (X9) ---------------------------------------------------- */
2236
2237 /*
2238 * Reset the embedding levels for some non-graphic characters (L1).
2239 * This method also sets appropriate levels for BN, and
2240 * explicit embedding types that are supposed to have been removed
2241 * from the paragraph in (X9).
2242 */
2243 private void adjustWSLevels() {
2244 int i;
2245
2246 if ((flags & MASK_WS) != 0) {
2247 int flag;
2248 i = trailingWSStart;
2249 while (i > 0) {
2250 /* reset a sequence of WS/BN before eop and B/S to the paragraph paraLevel */
2251 while (i > 0 && ((flag = DirPropFlagNC(dirProps[--i])) & MASK_WS) != 0) {
2252 if (orderParagraphsLTR && (flag & DirPropFlag(B)) != 0) {
2253 levels[i] = 0;
2254 } else {
2255 levels[i] = GetParaLevelAt(i);
2256 }
2257 }
2258
2259 /* reset BN to the next character's paraLevel until B/S, which restarts above loop */
2260 /* here, i+1 is guaranteed to be <length */
2261 while (i > 0) {
2262 flag = DirPropFlagNC(dirProps[--i]);
2263 if ((flag & MASK_BN_EXPLICIT) != 0) {
2264 levels[i] = levels[i + 1];
2265 } else if (orderParagraphsLTR && (flag & DirPropFlag(B)) != 0) {
2266 levels[i] = 0;
2267 break;
2268 } else if ((flag & MASK_B_S) != 0){
2269 levels[i] = GetParaLevelAt(i);
2270 break;
2271 }
2272 }
2273 }
2274 }
2275 }
2276
2277 private int Bidi_Min(int x, int y) {
2278 return x < y ? x : y;
2279 }
2280
2281 private int Bidi_Abs(int x) {
2282 return x >= 0 ? x : -x;
2283 }
2284
2285 /**
2286 * Perform the Unicode Bidi algorithm. It is defined in the
2287 * <a href="http://www.unicode.org/unicode/reports/tr9/">Unicode Standard Annex #9</a>,
2288 * version 13,
2289 * also described in The Unicode Standard, Version 4.0 .<p>
2290 *
2291 * This method takes a piece of plain text containing one or more paragraphs,
2292 * with or without externally specified embedding levels from <i>styled</i>
2293 * text and computes the left-right-directionality of each character.<p>
2294 *
2295 * If the entire text is all of the same directionality, then
2296 * the method may not perform all the steps described by the algorithm,
2297 * i.e., some levels may not be the same as if all steps were performed.
2298 * This is not relevant for unidirectional text.<br>
2299 * For example, in pure LTR text with numbers the numbers would get
2300 * a resolved level of 2 higher than the surrounding text according to
2301 * the algorithm. This implementation may set all resolved levels to
2302 * the same value in such a case.<p>
2303 *
2304 * The text can be composed of multiple paragraphs. Occurrence of a block
2305 * separator in the text terminates a paragraph, and whatever comes next starts
2306 * a new paragraph. The exception to this rule is when a Carriage Return (CR)
2307 * is followed by a Line Feed (LF). Both CR and LF are block separators, but
2308 * in that case, the pair of characters is considered as terminating the
2309 * preceding paragraph, and a new paragraph will be started by a character
2310 * coming after the LF.
2311 *
2312 * Although the text is passed here as a <code>String</code>, it is
2313 * stored internally as an array of characters. Therefore the
2314 * documentation will refer to indexes of the characters in the text.
2315 *
2316 * @param text contains the text that the Bidi algorithm will be performed
2317 * on. This text can be retrieved with <code>getText()</code> or
2318 * <code>getTextAsString</code>.<br>
2319 *
2320 * @param paraLevel specifies the default level for the text;
2321 * it is typically 0 (LTR) or 1 (RTL).
2322 * If the method shall determine the paragraph level from the text,
2323 * then <code>paraLevel</code> can be set to
2324 * either <code>LEVEL_DEFAULT_LTR</code>
2325 * or <code>LEVEL_DEFAULT_RTL</code>; if the text contains multiple
2326 * paragraphs, the paragraph level shall be determined separately for
2327 * each paragraph; if a paragraph does not include any strongly typed
2328 * character, then the desired default is used (0 for LTR or 1 for RTL).
2329 * Any other value between 0 and <code>MAX_EXPLICIT_LEVEL</code>
2330 * is also valid, with odd levels indicating RTL.
2331 *
2332 * @param embeddingLevels (in) may be used to preset the embedding and override levels,
2333 * ignoring characters like LRE and PDF in the text.
2334 * A level overrides the directional property of its corresponding
2335 * (same index) character if the level has the
2336 * <code>LEVEL_OVERRIDE</code> bit set.<br><br>
2337 * Except for that bit, it must be
2338 * <code>paraLevel<=embeddingLevels[]<=MAX_EXPLICIT_LEVEL</code>,
2339 * with one exception: a level of zero may be specified for a
2340 * paragraph separator even if <code>paraLevel>0</code> when multiple
2341 * paragraphs are submitted in the same call to <code>setPara()</code>.<br><br>
2342 * <strong>Caution: </strong>A reference to this array, not a copy
2343 * of the levels, will be stored in the <code>Bidi</code> object;
2344 * the <code>embeddingLevels</code>
2345 * should not be modified to avoid unexpected results on subsequent
2346 * Bidi operations. However, the <code>setPara()</code> and
2347 * <code>setLine()</code> methods may modify some or all of the
2348 * levels.<br><br>
2349 * <strong>Note:</strong> the <code>embeddingLevels</code> array must
2350 * have one entry for each character in <code>text</code>.
2351 *
2352 * @throws IllegalArgumentException if the values in embeddingLevels are
2353 * not within the allowed range
2354 *
2355 * @see #LEVEL_DEFAULT_LTR
2356 * @see #LEVEL_DEFAULT_RTL
2357 * @see #LEVEL_OVERRIDE
2358 * @see #MAX_EXPLICIT_LEVEL
2359 * @stable ICU 3.8
2360 */
2361 void setPara(String text, byte paraLevel, byte[] embeddingLevels)
2362 {
2363 if (text == null) {
2364 setPara(new char[0], paraLevel, embeddingLevels);
2365 } else {
2366 setPara(text.toCharArray(), paraLevel, embeddingLevels);
2367 }
2368 }
2369
2370 /**
2371 * Perform the Unicode Bidi algorithm. It is defined in the
2372 * <a href="http://www.unicode.org/unicode/reports/tr9/">Unicode Standard Annex #9</a>,
2373 * version 13,
2374 * also described in The Unicode Standard, Version 4.0 .<p>
2375 *
2376 * This method takes a piece of plain text containing one or more paragraphs,
2377 * with or without externally specified embedding levels from <i>styled</i>
2378 * text and computes the left-right-directionality of each character.<p>
2379 *
2380 * If the entire text is all of the same directionality, then
2381 * the method may not perform all the steps described by the algorithm,
2382 * i.e., some levels may not be the same as if all steps were performed.
2383 * This is not relevant for unidirectional text.<br>
2384 * For example, in pure LTR text with numbers the numbers would get
2385 * a resolved level of 2 higher than the surrounding text according to
2386 * the algorithm. This implementation may set all resolved levels to
2387 * the same value in such a case.<p>
2388 *
2389 * The text can be composed of multiple paragraphs. Occurrence of a block
2390 * separator in the text terminates a paragraph, and whatever comes next starts
2391 * a new paragraph. The exception to this rule is when a Carriage Return (CR)
2392 * is followed by a Line Feed (LF). Both CR and LF are block separators, but
2393 * in that case, the pair of characters is considered as terminating the
2394 * preceding paragraph, and a new paragraph will be started by a character
2395 * coming after the LF.
2396 *
2397 * The text is stored internally as an array of characters. Therefore the
2398 * documentation will refer to indexes of the characters in the text.
2399 *
2400 * @param chars contains the text that the Bidi algorithm will be performed
2401 * on. This text can be retrieved with <code>getText()</code> or
2402 * <code>getTextAsString</code>.<br>
2403 *
2404 * @param paraLevel specifies the default level for the text;
2405 * it is typically 0 (LTR) or 1 (RTL).
2406 * If the method shall determine the paragraph level from the text,
2407 * then <code>paraLevel</code> can be set to
2408 * either <code>LEVEL_DEFAULT_LTR</code>
2409 * or <code>LEVEL_DEFAULT_RTL</code>; if the text contains multiple
2410 * paragraphs, the paragraph level shall be determined separately for
2411 * each paragraph; if a paragraph does not include any strongly typed
2412 * character, then the desired default is used (0 for LTR or 1 for RTL).
2413 * Any other value between 0 and <code>MAX_EXPLICIT_LEVEL</code>
2414 * is also valid, with odd levels indicating RTL.
2415 *
2416 * @param embeddingLevels (in) may be used to preset the embedding and
2417 * override levels, ignoring characters like LRE and PDF in the text.
2418 * A level overrides the directional property of its corresponding
2419 * (same index) character if the level has the
2420 * <code>LEVEL_OVERRIDE</code> bit set.<br><br>
2421 * Except for that bit, it must be
2422 * <code>paraLevel<=embeddingLevels[]<=MAX_EXPLICIT_LEVEL</code>,
2423 * with one exception: a level of zero may be specified for a
2424 * paragraph separator even if <code>paraLevel>0</code> when multiple
2425 * paragraphs are submitted in the same call to <code>setPara()</code>.<br><br>
2426 * <strong>Caution: </strong>A reference to this array, not a copy
2427 * of the levels, will be stored in the <code>Bidi</code> object;
2428 * the <code>embeddingLevels</code>
2429 * should not be modified to avoid unexpected results on subsequent
2430 * Bidi operations. However, the <code>setPara()</code> and
2431 * <code>setLine()</code> methods may modify some or all of the
2432 * levels.<br><br>
2433 * <strong>Note:</strong> the <code>embeddingLevels</code> array must
2434 * have one entry for each character in <code>text</code>.
2435 *
2436 * @throws IllegalArgumentException if the values in embeddingLevels are
2437 * not within the allowed range
2438 *
2439 * @see #LEVEL_DEFAULT_LTR
2440 * @see #LEVEL_DEFAULT_RTL
2441 * @see #LEVEL_OVERRIDE
2442 * @see #MAX_EXPLICIT_LEVEL
2443 * @stable ICU 3.8
2444 */
2445 public void setPara(char[] chars, byte paraLevel, byte[] embeddingLevels)
2446 {
2447 /* check the argument values */
2448 if (paraLevel < INTERNAL_LEVEL_DEFAULT_LTR) {
2449 verifyRange(paraLevel, 0, MAX_EXPLICIT_LEVEL + 1);
2450 }
2451 if (chars == null) {
2452 chars = new char[0];
2453 }
2454
2455 /* initialize the Bidi object */
2456 this.paraBidi = null; /* mark unfinished setPara */
2457 this.text = chars;
2458 this.length = this.originalLength = this.resultLength = text.length;
2459 this.paraLevel = paraLevel;
2460 this.direction = Bidi.DIRECTION_LEFT_TO_RIGHT;
2461 this.paraCount = 1;
2462
2463 /* Allocate zero-length arrays instead of setting to null here; then
2464 * checks for null in various places can be eliminated.
2465 */
2466 dirProps = new byte[0];
2467 levels = new byte[0];
2468 runs = new BidiRun[0];
2469 isGoodLogicalToVisualRunsMap = false;
2470 insertPoints.size = 0; /* clean up from last call */
2471 insertPoints.confirmed = 0; /* clean up from last call */
2472
2473 /*
2474 * Save the original paraLevel if contextual; otherwise, set to 0.
2475 */
2476 if (IsDefaultLevel(paraLevel)) {
2477 defaultParaLevel = paraLevel;
2478 } else {
2479 defaultParaLevel = 0;
2480 }
2481
2482 if (length == 0) {
2483 /*
2484 * For an empty paragraph, create a Bidi object with the paraLevel and
2485 * the flags and the direction set but without allocating zero-length arrays.
2486 * There is nothing more to do.
2487 */
2488 if (IsDefaultLevel(paraLevel)) {
2489 this.paraLevel &= 1;
2490 defaultParaLevel = 0;
2491 }
2492 if ((this.paraLevel & 1) != 0) {
2493 flags = DirPropFlag(R);
2494 direction = Bidi.DIRECTION_RIGHT_TO_LEFT;
2495 } else {
2496 flags = DirPropFlag(L);
2497 direction = Bidi.DIRECTION_LEFT_TO_RIGHT;
2498 }
2499
2500 runCount = 0;
2501 paraCount = 0;
2502 paraBidi = this; /* mark successful setPara */
2503 return;
2504 }
2505
2506 runCount = -1;
2507
2508 /*
2509 * Get the directional properties,
2510 * the flags bit-set, and
2511 * determine the paragraph level if necessary.
2512 */
2513 getDirPropsMemory(length);
2514 dirProps = dirPropsMemory;
2515 getDirProps();
2516
2517 /* the processed length may have changed if OPTION_STREAMING is set */
2518 trailingWSStart = length; /* the levels[] will reflect the WS run */
2519
2520 /* allocate paras memory */
2521 if (paraCount > 1) {
2522 getInitialParasMemory(paraCount);
2523 paras = parasMemory;
2524 paras[paraCount - 1] = length;
2525 } else {
2526 /* initialize paras for single paragraph */
2527 paras = simpleParas;
2528 simpleParas[0] = length;
2529 }
2530
2531 /* are explicit levels specified? */
2532 if (embeddingLevels == null) {
2533 /* no: determine explicit levels according to the (Xn) rules */
2534 getLevelsMemory(length);
2535 levels = levelsMemory;
2536 direction = resolveExplicitLevels();
2537 } else {
2538 /* set BN for all explicit codes, check that all levels are 0 or paraLevel..MAX_EXPLICIT_LEVEL */
2539 levels = embeddingLevels;
2540 direction = checkExplicitLevels();
2541 }
2542
2543 /*
2544 * The steps after (X9) in the Bidi algorithm are performed only if
2545 * the paragraph text has mixed directionality!
2546 */
2547 switch (direction) {
2548 case Bidi.DIRECTION_LEFT_TO_RIGHT:
2549 /* make sure paraLevel is even */
2550 paraLevel = (byte)((paraLevel + 1) & ~1);
2551
2552 /* all levels are implicitly at paraLevel (important for getLevels()) */
2553 trailingWSStart = 0;
2554 break;
2555 case Bidi.DIRECTION_RIGHT_TO_LEFT:
2556 /* make sure paraLevel is odd */
2557 paraLevel |= 1;
2558
2559 /* all levels are implicitly at paraLevel (important for getLevels()) */
2560 trailingWSStart = 0;
2561 break;
2562 default:
2563 this.impTabPair = impTab_DEFAULT;
2564
2565 /*
2566 * If there are no external levels specified and there
2567 * are no significant explicit level codes in the text,
2568 * then we can treat the entire paragraph as one run.
2569 * Otherwise, we need to perform the following rules on runs of
2570 * the text with the same embedding levels. (X10)
2571 * "Significant" explicit level codes are ones that actually
2572 * affect non-BN characters.
2573 * Examples for "insignificant" ones are empty embeddings
2574 * LRE-PDF, LRE-RLE-PDF-PDF, etc.
2575 */
2576 if (embeddingLevels == null && paraCount <= 1 &&
2577 (flags & DirPropFlagMultiRuns) == 0) {
2578 resolveImplicitLevels(0, length,
2579 GetLRFromLevel(GetParaLevelAt(0)),
2580 GetLRFromLevel(GetParaLevelAt(length - 1)));
2581 } else {
2582 /* sor, eor: start and end types of same-level-run */
2583 int start, limit = 0;
2584 byte level, nextLevel;
2585 short sor, eor;
2586
2587 /* determine the first sor and set eor to it because of the loop body (sor=eor there) */
2588 level = GetParaLevelAt(0);
2589 nextLevel = levels[0];
2590 if (level < nextLevel) {
2591 eor = GetLRFromLevel(nextLevel);
2592 } else {
2593 eor = GetLRFromLevel(level);
2594 }
2595
2596 do {
2597 /* determine start and limit of the run (end points just behind the run) */
2598
2599 /* the values for this run's start are the same as for the previous run's end */
2600 start = limit;
2601 level = nextLevel;
2602 if ((start > 0) && (NoContextRTL(dirProps[start - 1]) == B)) {
2603 /* except if this is a new paragraph, then set sor = para level */
2604 sor = GetLRFromLevel(GetParaLevelAt(start));
2605 } else {
2606 sor = eor;
2607 }
2608
2609 /* search for the limit of this run */
2610 while (++limit < length && levels[limit] == level) {}
2611
2612 /* get the correct level of the next run */
2613 if (limit < length) {
2614 nextLevel = levels[limit];
2615 } else {
2616 nextLevel = GetParaLevelAt(length - 1);
2617 }
2618
2619 /* determine eor from max(level, nextLevel); sor is last run's eor */
2620 if ((level & ~INTERNAL_LEVEL_OVERRIDE) < (nextLevel & ~INTERNAL_LEVEL_OVERRIDE)) {
2621 eor = GetLRFromLevel(nextLevel);
2622 } else {
2623 eor = GetLRFromLevel(level);
2624 }
2625
2626 /* if the run consists of overridden directional types, then there
2627 are no implicit types to be resolved */
2628 if ((level & INTERNAL_LEVEL_OVERRIDE) == 0) {
2629 resolveImplicitLevels(start, limit, sor, eor);
2630 } else {
2631 /* remove the LEVEL_OVERRIDE flags */
2632 do {
2633 levels[start++] &= ~INTERNAL_LEVEL_OVERRIDE;
2634 } while (start < limit);
2635 }
2636 } while (limit < length);
2637 }
2638
2639 /* reset the embedding levels for some non-graphic characters (L1), (X9) */
2640 adjustWSLevels();
2641
2642 break;
2643 }
2644
2645 resultLength += insertPoints.size;
2646 paraBidi = this; /* mark successful setPara */
2647 }
2648
2649 /**
2650 * Perform the Unicode Bidi algorithm on a given paragraph, as defined in the
2651 * <a href="http://www.unicode.org/unicode/reports/tr9/">Unicode Standard Annex #9</a>,
2652 * version 13,
2653 * also described in The Unicode Standard, Version 4.0 .<p>
2654 *
2655 * This method takes a paragraph of text and computes the
2656 * left-right-directionality of each character. The text should not
2657 * contain any Unicode block separators.<p>
2658 *
2659 * The RUN_DIRECTION attribute in the text, if present, determines the base
2660 * direction (left-to-right or right-to-left). If not present, the base
2661 * direction is computed using the Unicode Bidirectional Algorithm,
2662 * defaulting to left-to-right if there are no strong directional characters
2663 * in the text. This attribute, if present, must be applied to all the text
2664 * in the paragraph.<p>
2665 *
2666 * The BIDI_EMBEDDING attribute in the text, if present, represents
2667 * embedding level information. Negative values from -1 to -62 indicate
2668 * overrides at the absolute value of the level. Positive values from 1 to
2669 * 62 indicate embeddings. Where values are zero or not defined, the base
2670 * embedding level as determined by the base direction is assumed.<p>
2671 *
2672 * The NUMERIC_SHAPING attribute in the text, if present, converts European
2673 * digits to other decimal digits before running the bidi algorithm. This
2674 * attribute, if present, must be applied to all the text in the paragraph.
2675 *
2676 * If the entire text is all of the same directionality, then
2677 * the method may not perform all the steps described by the algorithm,
2678 * i.e., some levels may not be the same as if all steps were performed.
2679 * This is not relevant for unidirectional text.<br>
2680 * For example, in pure LTR text with numbers the numbers would get
2681 * a resolved level of 2 higher than the surrounding text according to
2682 * the algorithm. This implementation may set all resolved levels to
2683 * the same value in such a case.<p>
2684 *
2685 * @param paragraph a paragraph of text with optional character and
2686 * paragraph attribute information
2687 * @stable ICU 3.8
2688 */
2689 public void setPara(AttributedCharacterIterator paragraph)
2690 {
2691 byte paraLvl;
2692 char ch = paragraph.first();
2693 Boolean runDirection =
2694 (Boolean) paragraph.getAttribute(TextAttributeConstants.RUN_DIRECTION);
2695 Object shaper = paragraph.getAttribute(TextAttributeConstants.NUMERIC_SHAPING);
2696 if (runDirection == null) {
2697 paraLvl = INTERNAL_LEVEL_DEFAULT_LTR;
2698 } else {
2699 paraLvl = (runDirection.equals(TextAttributeConstants.RUN_DIRECTION_LTR)) ?
2700 (byte)Bidi.DIRECTION_LEFT_TO_RIGHT : (byte)Bidi.DIRECTION_RIGHT_TO_LEFT;
2701 }
2702
2703 byte[] lvls = null;
2704 int len = paragraph.getEndIndex() - paragraph.getBeginIndex();
2705 byte[] embeddingLevels = new byte[len];
2706 char[] txt = new char[len];
2707 int i = 0;
2708 while (ch != AttributedCharacterIterator.DONE) {
2709 txt[i] = ch;
2710 Integer embedding =
2711 (Integer) paragraph.getAttribute(TextAttributeConstants.BIDI_EMBEDDING);
2712 if (embedding != null) {
2713 byte level = embedding.byteValue();
2714 if (level == 0) {
2715 /* no-op */
2716 } else if (level < 0) {
2717 lvls = embeddingLevels;
2718 embeddingLevels[i] = (byte)((0 - level) | INTERNAL_LEVEL_OVERRIDE);
2719 } else {
2720 lvls = embeddingLevels;
2721 embeddingLevels[i] = level;
2722 }
2723 }
2724 ch = paragraph.next();
2725 ++i;
2726 }
2727
2728 if (shaper != null) {
2729 NumericShapings.shape(shaper, txt, 0, len);
2730 }
2731 setPara(txt, paraLvl, lvls);
2732 }
2733
2734 /**
2735 * Specify whether block separators must be allocated level zero,
2736 * so that successive paragraphs will progress from left to right.
2737 * This method must be called before <code>setPara()</code>.
2738 * Paragraph separators (B) may appear in the text. Setting them to level zero
2739 * means that all paragraph separators (including one possibly appearing
2740 * in the last text position) are kept in the reordered text after the text
2741 * that they follow in the source text.
2742 * When this feature is not enabled, a paragraph separator at the last
2743 * position of the text before reordering will go to the first position
2744 * of the reordered text when the paragraph level is odd.
2745 *
2746 * @param ordarParaLTR specifies whether paragraph separators (B) must
2747 * receive level 0, so that successive paragraphs progress from left to right.
2748 *
2749 * @see #setPara
2750 * @stable ICU 3.8
2751 */
2752 private void orderParagraphsLTR(boolean ordarParaLTR) {
2753 orderParagraphsLTR = ordarParaLTR;
2754 }
2755
2756 /**
2757 * Get the directionality of the text.
2758 *
2759 * @return a value of <code>LTR</code>, <code>RTL</code> or <code>MIXED</code>
2760 * that indicates if the entire text
2761 * represented by this object is unidirectional,
2762 * and which direction, or if it is mixed-directional.
2763 *
2764 * @throws IllegalStateException if this call is not preceded by a successful
2765 * call to <code>setPara</code> or <code>setLine</code>
2766 *
2767 * @see #LTR
2768 * @see #RTL
2769 * @see #MIXED
2770 * @stable ICU 3.8
2771 */
2772 private byte getDirection()
2773 {
2774 verifyValidParaOrLine();
2775 return direction;
2776 }
2777
2778 /**
2779 * Get the length of the text.
2780 *
2781 * @return The length of the text that the <code>Bidi</code> object was
2782 * created for.
2783 *
2784 * @throws IllegalStateException if this call is not preceded by a successful
2785 * call to <code>setPara</code> or <code>setLine</code>
2786 * @stable ICU 3.8
2787 */
2788 public int getLength()
2789 {
2790 verifyValidParaOrLine();
2791 return originalLength;
2792 }
2793
2794 /* paragraphs API methods ------------------------------------------------- */
2795
2796 /**
2797 * Get the paragraph level of the text.
2798 *
2799 * @return The paragraph level. If there are multiple paragraphs, their
2800 * level may vary if the required paraLevel is LEVEL_DEFAULT_LTR or
2801 * LEVEL_DEFAULT_RTL. In that case, the level of the first paragraph
2802 * is returned.
2803 *
2804 * @throws IllegalStateException if this call is not preceded by a successful
2805 * call to <code>setPara</code> or <code>setLine</code>
2806 *
2807 * @see #LEVEL_DEFAULT_LTR
2808 * @see #LEVEL_DEFAULT_RTL
2809 * @see #getParagraph
2810 * @see #getParagraphByIndex
2811 * @stable ICU 3.8
2812 */
2813 public byte getParaLevel()
2814 {
2815 verifyValidParaOrLine();
2816 return paraLevel;
2817 }
2818
2819 /**
2820 * Get the index of a paragraph, given a position within the text.<p>
2821 *
2822 * @param charIndex is the index of a character within the text, in the
2823 * range <code>[0..getProcessedLength()-1]</code>.
2824 *
2825 * @return The index of the paragraph containing the specified position,
2826 * starting from 0.
2827 *
2828 * @throws IllegalStateException if this call is not preceded by a successful
2829 * call to <code>setPara</code> or <code>setLine</code>
2830 * @throws IllegalArgumentException if charIndex is not within the legal range
2831 *
2832 * @see com.ibm.icu.text.BidiRun
2833 * @see #getProcessedLength
2834 * @stable ICU 3.8
2835 */
2836 public int getParagraphIndex(int charIndex)
2837 {
2838 verifyValidParaOrLine();
2839 BidiBase bidi = paraBidi; /* get Para object if Line object */
2840 verifyRange(charIndex, 0, bidi.length);
2841 int paraIndex;
2842 for (paraIndex = 0; charIndex >= bidi.paras[paraIndex]; paraIndex++) {
2843 }
2844 return paraIndex;
2845 }
2846
2847 /**
2848 * <code>setLine()</code> returns a <code>Bidi</code> object to
2849 * contain the reordering information, especially the resolved levels,
2850 * for all the characters in a line of text. This line of text is
2851 * specified by referring to a <code>Bidi</code> object representing
2852 * this information for a piece of text containing one or more paragraphs,
2853 * and by specifying a range of indexes in this text.<p>
2854 * In the new line object, the indexes will range from 0 to <code>limit-start-1</code>.<p>
2855 *
2856 * This is used after calling <code>setPara()</code>
2857 * for a piece of text, and after line-breaking on that text.
2858 * It is not necessary if each paragraph is treated as a single line.<p>
2859 *
2860 * After line-breaking, rules (L1) and (L2) for the treatment of
2861 * trailing WS and for reordering are performed on
2862 * a <code>Bidi</code> object that represents a line.<p>
2863 *
2864 * <strong>Important: </strong>the line <code>Bidi</code> object may
2865 * reference data within the global text <code>Bidi</code> object.
2866 * You should not alter the content of the global text object until
2867 * you are finished using the line object.
2868 *
2869 * @param start is the line's first index into the text.
2870 *
2871 * @param limit is just behind the line's last index into the text
2872 * (its last index +1).
2873 *
2874 * @return a <code>Bidi</code> object that will now represent a line of the text.
2875 *
2876 * @throws IllegalStateException if this call is not preceded by a successful
2877 * call to <code>setPara</code>
2878 * @throws IllegalArgumentException if start and limit are not in the range
2879 * <code>0<=start<limit<=getProcessedLength()</code>,
2880 * or if the specified line crosses a paragraph boundary
2881 *
2882 * @see #setPara
2883 * @see #getProcessedLength
2884 * @stable ICU 3.8
2885 */
2886 public Bidi setLine(Bidi bidi, BidiBase bidiBase, Bidi newBidi, BidiBase newBidiBase, int start, int limit)
2887 {
2888 verifyValidPara();
2889 verifyRange(start, 0, limit);
2890 verifyRange(limit, 0, length+1);
2891
2892 return BidiLine.setLine(bidi, this, newBidi, newBidiBase, start, limit);
2893 }
2894
2895 /**
2896 * Get the level for one character.
2897 *
2898 * @param charIndex the index of a character.
2899 *
2900 * @return The level for the character at <code>charIndex</code>.
2901 *
2902 * @throws IllegalStateException if this call is not preceded by a successful
2903 * call to <code>setPara</code> or <code>setLine</code>
2904 * @throws IllegalArgumentException if charIndex is not in the range
2905 * <code>0<=charIndex<getProcessedLength()</code>
2906 *
2907 * @see #getProcessedLength
2908 * @stable ICU 3.8
2909 */
2910 public byte getLevelAt(int charIndex)
2911 {
2912 if (charIndex < 0 || charIndex >= length) {
2913 return (byte)getBaseLevel();
2914 }
2915 verifyValidParaOrLine();
2916 verifyRange(charIndex, 0, length);
2917 return BidiLine.getLevelAt(this, charIndex);
2918 }
2919
2920 /**
2921 * Get an array of levels for each character.<p>
2922 *
2923 * Note that this method may allocate memory under some
2924 * circumstances, unlike <code>getLevelAt()</code>.
2925 *
2926 * @return The levels array for the text,
2927 * or <code>null</code> if an error occurs.
2928 *
2929 * @throws IllegalStateException if this call is not preceded by a successful
2930 * call to <code>setPara</code> or <code>setLine</code>
2931 * @stable ICU 3.8
2932 */
2933 private byte[] getLevels()
2934 {
2935 verifyValidParaOrLine();
2936 if (length <= 0) {
2937 return new byte[0];
2938 }
2939 return BidiLine.getLevels(this);
2940 }
2941
2942 /**
2943 * Get the number of runs.
2944 * This method may invoke the actual reordering on the
2945 * <code>Bidi</code> object, after <code>setPara()</code>
2946 * may have resolved only the levels of the text. Therefore,
2947 * <code>countRuns()</code> may have to allocate memory,
2948 * and may throw an exception if it fails to do so.
2949 *
2950 * @return The number of runs.
2951 *
2952 * @throws IllegalStateException if this call is not preceded by a successful
2953 * call to <code>setPara</code> or <code>setLine</code>
2954 * @stable ICU 3.8
2955 */
2956 public int countRuns()
2957 {
2958 verifyValidParaOrLine();
2959 BidiLine.getRuns(this);
2960 return runCount;
2961 }
2962
2963 /**
2964 * Get a visual-to-logical index map (array) for the characters in the
2965 * <code>Bidi</code> (paragraph or line) object.
2966 * <p>
2967 * Some values in the map may be <code>MAP_NOWHERE</code> if the
2968 * corresponding text characters are Bidi marks inserted in the visual
2969 * output by the option <code>OPTION_INSERT_MARKS</code>.
2970 * <p>
2971 * When the visual output is altered by using options of
2972 * <code>writeReordered()</code> such as <code>INSERT_LRM_FOR_NUMERIC</code>,
2973 * <code>KEEP_BASE_COMBINING</code>, <code>OUTPUT_REVERSE</code>,
2974 * <code>REMOVE_BIDI_CONTROLS</code>, the logical positions returned may not
2975 * be correct. It is advised to use, when possible, reordering options
2976 * such as {@link #OPTION_INSERT_MARKS} and {@link #OPTION_REMOVE_CONTROLS}.
2977 *
2978 * @return an array of <code>getResultLength()</code>
2979 * indexes which will reflect the reordering of the characters.<br><br>
2980 * The index map will result in
2981 * <code>indexMap[visualIndex]==logicalIndex</code>, where
2982 * <code>indexMap</code> represents the returned array.
2983 *
2984 * @throws IllegalStateException if this call is not preceded by a successful
2985 * call to <code>setPara</code> or <code>setLine</code>
2986 *
2987 * @see #getLogicalMap
2988 * @see #getLogicalIndex
2989 * @see #getResultLength
2990 * @see #MAP_NOWHERE
2991 * @see #OPTION_INSERT_MARKS
2992 * @see #writeReordered
2993 * @stable ICU 3.8
2994 */
2995 private int[] getVisualMap()
2996 {
2997 /* countRuns() checks successful call to setPara/setLine */
2998 countRuns();
2999 if (resultLength <= 0) {
3000 return new int[0];
3001 }
3002 return BidiLine.getVisualMap(this);
3003 }
3004
3005 /**
3006 * This is a convenience method that does not use a <code>Bidi</code> object.
3007 * It is intended to be used for when an application has determined the levels
3008 * of objects (character sequences) and just needs to have them reordered (L2).
3009 * This is equivalent to using <code>getVisualMap()</code> on a
3010 * <code>Bidi</code> object.
3011 *
3012 * @param levels is an array of levels that have been determined by
3013 * the application.
3014 *
3015 * @return an array of <code>levels.length</code>
3016 * indexes which will reflect the reordering of the characters.<p>
3017 * The index map will result in
3018 * <code>indexMap[visualIndex]==logicalIndex</code>, where
3019 * <code>indexMap</code> represents the returned array.
3020 *
3021 * @stable ICU 3.8
3022 */
3023 private static int[] reorderVisual(byte[] levels)
3024 {
3025 return BidiLine.reorderVisual(levels);
3026 }
3027
3028 /**
3029 * Constant indicating that the base direction depends on the first strong
3030 * directional character in the text according to the Unicode Bidirectional
3031 * Algorithm. If no strong directional character is present, the base
3032 * direction is left-to-right.
3033 * @stable ICU 3.8
3034 */
3035 private static final int INTERNAL_DIRECTION_DEFAULT_LEFT_TO_RIGHT = 0x7e;
3036
3037 /**
3038 * Constant indicating that the base direction depends on the first strong
3039 * directional character in the text according to the Unicode Bidirectional
3040 * Algorithm. If no strong directional character is present, the base
3041 * direction is right-to-left.
3042 * @stable ICU 3.8
3043 */
3044 private static final int INTERMAL_DIRECTION_DEFAULT_RIGHT_TO_LEFT = 0x7f;
3045
3046 /**
3047 * Create Bidi from the given text, embedding, and direction information.
3048 * The embeddings array may be null. If present, the values represent
3049 * embedding level information. Negative values from -1 to -61 indicate
3050 * overrides at the absolute value of the level. Positive values from 1 to
3051 * 61 indicate embeddings. Where values are zero, the base embedding level
3052 * as determined by the base direction is assumed.<p>
3053 *
3054 * Note: this constructor calls setPara() internally.
3055 *
3056 * @param text an array containing the paragraph of text to process.
3057 * @param textStart the index into the text array of the start of the
3058 * paragraph.
3059 * @param embeddings an array containing embedding values for each character
3060 * in the paragraph. This can be null, in which case it is assumed
3061 * that there is no external embedding information.
3062 * @param embStart the index into the embedding array of the start of the
3063 * paragraph.
3064 * @param paragraphLength the length of the paragraph in the text and
3065 * embeddings arrays.
3066 * @param flags a collection of flags that control the algorithm. The
3067 * algorithm understands the flags DIRECTION_LEFT_TO_RIGHT,
3068 * DIRECTION_RIGHT_TO_LEFT, DIRECTION_DEFAULT_LEFT_TO_RIGHT, and
3069 * DIRECTION_DEFAULT_RIGHT_TO_LEFT. Other values are reserved.
3070 *
3071 * @throws IllegalArgumentException if the values in embeddings are
3072 * not within the allowed range
3073 *
3074 * @see #DIRECTION_LEFT_TO_RIGHT
3075 * @see #DIRECTION_RIGHT_TO_LEFT
3076 * @see #DIRECTION_DEFAULT_LEFT_TO_RIGHT
3077 * @see #DIRECTION_DEFAULT_RIGHT_TO_LEFT
3078 * @stable ICU 3.8
3079 */
3080 public BidiBase(char[] text,
3081 int textStart,
3082 byte[] embeddings,
3083 int embStart,
3084 int paragraphLength,
3085 int flags)
3086 {
3087 this(0, 0);
3088 byte paraLvl;
3089 switch (flags) {
3090 case Bidi.DIRECTION_LEFT_TO_RIGHT:
3091 default:
3092 paraLvl = Bidi.DIRECTION_LEFT_TO_RIGHT;
3093 break;
3094 case Bidi.DIRECTION_RIGHT_TO_LEFT:
3095 paraLvl = Bidi.DIRECTION_RIGHT_TO_LEFT;
3096 break;
3097 case Bidi.DIRECTION_DEFAULT_LEFT_TO_RIGHT:
3098 paraLvl = INTERNAL_LEVEL_DEFAULT_LTR;
3099 break;
3100 case Bidi.DIRECTION_DEFAULT_RIGHT_TO_LEFT:
3101 paraLvl = INTERNAL_LEVEL_DEFAULT_RTL;
3102 break;
3103 }
3104 byte[] paraEmbeddings;
3105 if (embeddings == null) {
3106 paraEmbeddings = null;
3107 } else {
3108 paraEmbeddings = new byte[paragraphLength];
3109 byte lev;
3110 for (int i = 0; i < paragraphLength; i++) {
3111 lev = embeddings[i + embStart];
3112 if (lev < 0) {
3113 lev = (byte)((- lev) | INTERNAL_LEVEL_OVERRIDE);
3114 } else if (lev == 0) {
3115 lev = paraLvl;
3116 if (paraLvl > MAX_EXPLICIT_LEVEL) {
3117 lev &= 1;
3118 }
3119 }
3120 paraEmbeddings[i] = lev;
3121 }
3122 }
3123 if (textStart == 0 && embStart == 0 && paragraphLength == text.length) {
3124 setPara(text, paraLvl, paraEmbeddings);
3125 } else {
3126 char[] paraText = new char[paragraphLength];
3127 System.arraycopy(text, textStart, paraText, 0, paragraphLength);
3128 setPara(paraText, paraLvl, paraEmbeddings);
3129 }
3130 }
3131
3132 /**
3133 * Return true if the line is not left-to-right or right-to-left. This means
3134 * it either has mixed runs of left-to-right and right-to-left text, or the
3135 * base direction differs from the direction of the only run of text.
3136 *
3137 * @return true if the line is not left-to-right or right-to-left.
3138 *
3139 * @throws IllegalStateException if this call is not preceded by a successful
3140 * call to <code>setPara</code>
3141 * @stable ICU 3.8
3142 */
3143 public boolean isMixed()
3144 {
3145 return (!isLeftToRight() && !isRightToLeft());
3146 }
3147
3148 /**
3149 * Return true if the line is all left-to-right text and the base direction
3150 * is left-to-right.
3151 *
3152 * @return true if the line is all left-to-right text and the base direction
3153 * is left-to-right.
3154 *
3155 * @throws IllegalStateException if this call is not preceded by a successful
3156 * call to <code>setPara</code>
3157 * @stable ICU 3.8
3158 */
3159 public boolean isLeftToRight()
3160 {
3161 return (getDirection() == Bidi.DIRECTION_LEFT_TO_RIGHT && (paraLevel & 1) == 0);
3162 }
3163
3164 /**
3165 * Return true if the line is all right-to-left text, and the base direction
3166 * is right-to-left
3167 *
3168 * @return true if the line is all right-to-left text, and the base
3169 * direction is right-to-left
3170 *
3171 * @throws IllegalStateException if this call is not preceded by a successful
3172 * call to <code>setPara</code>
3173 * @stable ICU 3.8
3174 */
3175 public boolean isRightToLeft()
3176 {
3177 return (getDirection() == Bidi.DIRECTION_RIGHT_TO_LEFT && (paraLevel & 1) == 1);
3178 }
3179
3180 /**
3181 * Return true if the base direction is left-to-right
3182 *
3183 * @return true if the base direction is left-to-right
3184 *
3185 * @throws IllegalStateException if this call is not preceded by a successful
3186 * call to <code>setPara</code> or <code>setLine</code>
3187 *
3188 * @stable ICU 3.8
3189 */
3190 public boolean baseIsLeftToRight()
3191 {
3192 return (getParaLevel() == Bidi.DIRECTION_LEFT_TO_RIGHT);
3193 }
3194
3195 /**
3196 * Return the base level (0 if left-to-right, 1 if right-to-left).
3197 *
3198 * @return the base level
3199 *
3200 * @throws IllegalStateException if this call is not preceded by a successful
3201 * call to <code>setPara</code> or <code>setLine</code>
3202 *
3203 * @stable ICU 3.8
3204 */
3205 public int getBaseLevel()
3206 {
3207 return getParaLevel();
3208 }
3209
3210 /**
3211 * Compute the logical to visual run mapping
3212 */
3213 private void getLogicalToVisualRunsMap()
3214 {
3215 if (isGoodLogicalToVisualRunsMap) {
3216 return;
3217 }
3218 int count = countRuns();
3219 if ((logicalToVisualRunsMap == null) ||
3220 (logicalToVisualRunsMap.length < count)) {
3221 logicalToVisualRunsMap = new int[count];
3222 }
3223 int i;
3224 long[] keys = new long[count];
3225 for (i = 0; i < count; i++) {
3226 keys[i] = ((long)(runs[i].start)<<32) + i;
3227 }
3228 Arrays.sort(keys);
3229 for (i = 0; i < count; i++) {
3230 logicalToVisualRunsMap[i] = (int)(keys[i] & 0x00000000FFFFFFFF);
3231 }
3232 keys = null;
3233 isGoodLogicalToVisualRunsMap = true;
3234 }
3235
3236 /**
3237 * Return the level of the nth logical run in this line.
3238 *
3239 * @param run the index of the run, between 0 and <code>countRuns()-1</code>
3240 *
3241 * @return the level of the run
3242 *
3243 * @throws IllegalStateException if this call is not preceded by a successful
3244 * call to <code>setPara</code> or <code>setLine</code>
3245 * @throws IllegalArgumentException if <code>run</code> is not in
3246 * the range <code>0<=run<countRuns()</code>
3247 * @stable ICU 3.8
3248 */
3249 public int getRunLevel(int run)
3250 {
3251 verifyValidParaOrLine();
3252 BidiLine.getRuns(this);
3253 if (run < 0 || run >= runCount) {
3254 return getParaLevel();
3255 }
3256 getLogicalToVisualRunsMap();
3257 return runs[logicalToVisualRunsMap[run]].level;
3258 }
3259
3260 /**
3261 * Return the index of the character at the start of the nth logical run in
3262 * this line, as an offset from the start of the line.
3263 *
3264 * @param run the index of the run, between 0 and <code>countRuns()</code>
3265 *
3266 * @return the start of the run
3267 *
3268 * @throws IllegalStateException if this call is not preceded by a successful
3269 * call to <code>setPara</code> or <code>setLine</code>
3270 * @throws IllegalArgumentException if <code>run</code> is not in
3271 * the range <code>0<=run<countRuns()</code>
3272 * @stable ICU 3.8
3273 */
3274 public int getRunStart(int run)
3275 {
3276 verifyValidParaOrLine();
3277 BidiLine.getRuns(this);
3278 if (runCount == 1) {
3279 return 0;
3280 } else if (run == runCount) {
3281 return length;
3282 }
3283 verifyIndex(run, 0, runCount);
3284 getLogicalToVisualRunsMap();
3285 return runs[logicalToVisualRunsMap[run]].start;
3286 }
3287
3288 /**
3289 * Return the index of the character past the end of the nth logical run in
3290 * this line, as an offset from the start of the line. For example, this
3291 * will return the length of the line for the last run on the line.
3292 *
3293 * @param run the index of the run, between 0 and <code>countRuns()</code>
3294 *
3295 * @return the limit of the run
3296 *
3297 * @throws IllegalStateException if this call is not preceded by a successful
3298 * call to <code>setPara</code> or <code>setLine</code>
3299 * @throws IllegalArgumentException if <code>run</code> is not in
3300 * the range <code>0<=run<countRuns()</code>
3301 * @stable ICU 3.8
3302 */
3303 public int getRunLimit(int run)
3304 {
3305 verifyValidParaOrLine();
3306 BidiLine.getRuns(this);
3307 if (runCount == 1) {
3308 return length;
3309 }
3310 verifyIndex(run, 0, runCount);
3311 getLogicalToVisualRunsMap();
3312 int idx = logicalToVisualRunsMap[run];
3313 int len = idx == 0 ? runs[idx].limit :
3314 runs[idx].limit - runs[idx-1].limit;
3315 return runs[idx].start + len;
3316 }
3317
3318 /**
3319 * Return true if the specified text requires bidi analysis. If this returns
3320 * false, the text will display left-to-right. Clients can then avoid
3321 * constructing a Bidi object. Text in the Arabic Presentation Forms area of
3322 * Unicode is presumed to already be shaped and ordered for display, and so
3323 * will not cause this method to return true.
3324 *
3325 * @param text the text containing the characters to test
3326 * @param start the start of the range of characters to test
3327 * @param limit the limit of the range of characters to test
3328 *
3329 * @return true if the range of characters requires bidi analysis
3330 *
3331 * @stable ICU 3.8
3332 */
3333 public static boolean requiresBidi(char[] text,
3334 int start,
3335 int limit)
3336 {
3337 final int RTLMask = (1 << Bidi.DIRECTION_RIGHT_TO_LEFT |
3338 1 << AL |
3339 1 << RLE |
3340 1 << RLO |
3341 1 << AN);
3342
3343 if (0 > start || start > limit || limit > text.length) {
3344 throw new IllegalArgumentException("Value start " + start +
3345 " is out of range 0 to " + limit);
3346 }
3347 for (int i = start; i < limit; ++i) {
3348 if (Character.isHighSurrogate(text[i]) && i < (limit-1) &&
3349 Character.isLowSurrogate(text[i+1])) {
3350 if (((1 << UCharacter.getDirection(Character.codePointAt(text, i))) & RTLMask) != 0) {
3351 return true;
3352 }
3353 } else if (((1 << UCharacter.getDirection(text[i])) & RTLMask) != 0) {
3354 return true;
3355 }
3356 }
3357 return false;
3358 }
3359
3360 /**
3361 * Reorder the objects in the array into visual order based on their levels.
3362 * This is a utility method to use when you have a collection of objects
3363 * representing runs of text in logical order, each run containing text at a
3364 * single level. The elements at <code>index</code> from
3365 * <code>objectStart</code> up to <code>objectStart + count</code> in the
3366 * objects array will be reordered into visual order assuming
3367 * each run of text has the level indicated by the corresponding element in
3368 * the levels array (at <code>index - objectStart + levelStart</code>).
3369 *
3370 * @param levels an array representing the bidi level of each object
3371 * @param levelStart the start position in the levels array
3372 * @param objects the array of objects to be reordered into visual order
3373 * @param objectStart the start position in the objects array
3374 * @param count the number of objects to reorder
3375 * @stable ICU 3.8
3376 */
3377 public static void reorderVisually(byte[] levels,
3378 int levelStart,
3379 Object[] objects,
3380 int objectStart,
3381 int count)
3382 {
3383 if (0 > levelStart || levels.length <= levelStart) {
3384 throw new IllegalArgumentException("Value levelStart " +
3385 levelStart + " is out of range 0 to " +
3386 (levels.length-1));
3387 }
3388 if (0 > objectStart || objects.length <= objectStart) {
3389 throw new IllegalArgumentException("Value objectStart " +
3390 levelStart + " is out of range 0 to " +
3391 (objects.length-1));
3392 }
3393 if (0 > count || objects.length < (objectStart+count)) {
3394 throw new IllegalArgumentException("Value count " +
3395 levelStart + " is out of range 0 to " +
3396 (objects.length - objectStart));
3397 }
3398 byte[] reorderLevels = new byte[count];
3399 System.arraycopy(levels, levelStart, reorderLevels, 0, count);
3400 int[] indexMap = reorderVisual(reorderLevels);
3401 Object[] temp = new Object[count];
3402 System.arraycopy(objects, objectStart, temp, 0, count);
3403 for (int i = 0; i < count; ++i) {
3404 objects[objectStart + i] = temp[indexMap[i]];
3405 }
3406 }
3407
3408 /**
3409 * Display the bidi internal state, used in debugging.
3410 */
3411 public String toString() {
3412 StringBuilder buf = new StringBuilder(getClass().getName());
3413
3414 buf.append("[dir: ");
3415 buf.append(direction);
3416 buf.append(" baselevel: ");
3417 buf.append(paraLevel);
3418 buf.append(" length: ");
3419 buf.append(length);
3420 buf.append(" runs: ");
3421 if (levels == null) {
3422 buf.append("none");
3423 } else {
3424 buf.append('[');
3425 buf.append(levels[0]);
3426 for (int i = 1; i < levels.length; i++) {
3427 buf.append(' ');
3428 buf.append(levels[i]);
3429 }
3430 buf.append(']');
3431 }
3432 buf.append(" text: [0x");
3433 buf.append(Integer.toHexString(text[0]));
3434 for (int i = 1; i < text.length; i++) {
3435 buf.append(" 0x");
3436 buf.append(Integer.toHexString(text[i]));
3437 }
3438 buf.append("]]");
3439
3440 return buf.toString();
3441 }
3442
3443 /**
3444 * A class that provides access to constants defined by
3445 * java.awt.font.TextAttribute without creating a static dependency.
3446 */
3447 private static class TextAttributeConstants {
3448 // Make sure to load the AWT's TextAttribute class before using the constants, if any.
3449 static {
3450 try {
3451 Class.forName("java.awt.font.TextAttribute", true, null);
3452 } catch (ClassNotFoundException e) {}
3453 }
3454 static final JavaAWTFontAccess jafa = SharedSecrets.getJavaAWTFontAccess();
3455
3456 /**
3457 * TextAttribute instances (or a fake Attribute type if
3458 * java.awt.font.TextAttribute is not present)
3459 */
3460 static final AttributedCharacterIterator.Attribute RUN_DIRECTION =
3461 getTextAttribute("RUN_DIRECTION");
3462 static final AttributedCharacterIterator.Attribute NUMERIC_SHAPING =
3463 getTextAttribute("NUMERIC_SHAPING");
3464 static final AttributedCharacterIterator.Attribute BIDI_EMBEDDING =
3465 getTextAttribute("BIDI_EMBEDDING");
3466
3467 /**
3468 * TextAttribute.RUN_DIRECTION_LTR
3469 */
3470 static final Boolean RUN_DIRECTION_LTR = (jafa == null) ?
3471 Boolean.FALSE : (Boolean)jafa.getTextAttributeConstant("RUN_DIRECTION_LTR");
3472
3473 @SuppressWarnings("serial")
3474 private static AttributedCharacterIterator.Attribute
3475 getTextAttribute(String name)
3476 {
3477 if (jafa == null) {
3478 // fake attribute
3479 return new AttributedCharacterIterator.Attribute(name) { };
3480 } else {
3481 return (AttributedCharacterIterator.Attribute)jafa.getTextAttributeConstant(name);
3482 }
3483 }
3484 }
3485
3486 /**
3487 * A class that provides access to java.awt.font.NumericShaper without
3488 * creating a static dependency.
3489 */
3490 private static class NumericShapings {
3491 // Make sure to load the AWT's NumericShaper class before calling shape, if any.
3492 static {
3493 try {
3494 Class.forName("java.awt.font.NumericShaper", true, null);
3495 } catch (ClassNotFoundException e) {}
3496 }
3497 static final JavaAWTFontAccess jafa = SharedSecrets.getJavaAWTFontAccess();
3498
3499 /**
3500 * Invokes NumericShaping shape(text,start,count) method.
3501 */
3502 static void shape(Object shaper, char[] text, int start, int count) {
3503 if (jafa != null) {
3504 jafa.shape(shaper, text, start, count);
3505 }
3506 }
3507 }
3508 }