Skip boundry neutral characters in bidi itemization
[profile/ivi/qtbase.git] / src / gui / text / qtextengine.cpp
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41
42 #include "qdebug.h"
43 #include "qtextformat.h"
44 #include "qtextformat_p.h"
45 #include "qtextengine_p.h"
46 #include "qabstracttextdocumentlayout.h"
47 #include "qtextlayout.h"
48 #include "qtextboundaryfinder.h"
49 #include "qvarlengtharray.h"
50 #include "qfont.h"
51 #include "qfont_p.h"
52 #include "qfontengine_p.h"
53 #include "qstring.h"
54 #include <private/qunicodetables_p.h>
55 #include "qtextdocument_p.h"
56 #include <qapplication.h>
57 #include <stdlib.h>
58
59
60 QT_BEGIN_NAMESPACE
61
62 namespace {
63 // Helper class used in QTextEngine::itemize
64 // keep it out here to allow us to keep supporting various compilers.
65 class Itemizer {
66 public:
67     Itemizer(const QString &string, const QScriptAnalysis *analysis, QScriptItemArray &items)
68         : m_string(string),
69         m_analysis(analysis),
70         m_items(items),
71         m_splitter(0)
72     {
73     }
74     ~Itemizer()
75     {
76         delete m_splitter;
77     }
78
79     /// generate the script items
80     /// The caps parameter is used to choose the algoritm of splitting text and assiging roles to the textitems
81     void generate(int start, int length, QFont::Capitalization caps)
82     {
83         if ((int)caps == (int)QFont::SmallCaps)
84             generateScriptItemsSmallCaps(reinterpret_cast<const ushort *>(m_string.unicode()), start, length);
85         else if(caps == QFont::Capitalize)
86             generateScriptItemsCapitalize(start, length);
87         else if(caps != QFont::MixedCase) {
88             generateScriptItemsAndChangeCase(start, length,
89                 caps == QFont::AllLowercase ? QScriptAnalysis::Lowercase : QScriptAnalysis::Uppercase);
90         }
91         else
92             generateScriptItems(start, length);
93     }
94
95 private:
96     enum { MaxItemLength = 4096 };
97
98     void generateScriptItemsAndChangeCase(int start, int length, QScriptAnalysis::Flags flags)
99     {
100         generateScriptItems(start, length);
101         if (m_items.isEmpty()) // the next loop won't work in that case
102             return;
103         QScriptItemArray::Iterator iter = m_items.end();
104         do {
105             iter--;
106             if (iter->analysis.flags < QScriptAnalysis::TabOrObject)
107                 iter->analysis.flags = flags;
108         } while (iter->position > start);
109     }
110
111     void generateScriptItems(int start, int length)
112     {
113         if (!length)
114             return;
115         const int end = start + length;
116         for (int i = start + 1; i < end; ++i) {
117             if ((m_analysis[i] == m_analysis[start])
118                 && m_analysis[i].flags < QScriptAnalysis::SpaceTabOrObject
119                 && i - start < MaxItemLength)
120                 continue;
121             m_items.append(QScriptItem(start, m_analysis[start]));
122             start = i;
123         }
124         m_items.append(QScriptItem(start, m_analysis[start]));
125     }
126
127     void generateScriptItemsCapitalize(int start, int length)
128     {
129         if (!length)
130             return;
131
132         if (!m_splitter)
133             m_splitter = new QTextBoundaryFinder(QTextBoundaryFinder::Word,
134                                                  m_string.constData(), m_string.length(),
135                                                  /*buffer*/0, /*buffer size*/0);
136
137         m_splitter->setPosition(start);
138         QScriptAnalysis itemAnalysis = m_analysis[start];
139
140         if (m_splitter->boundaryReasons() & QTextBoundaryFinder::StartWord) {
141             itemAnalysis.flags = QScriptAnalysis::Uppercase;
142             m_splitter->toNextBoundary();
143         }
144
145         const int end = start + length;
146         for (int i = start + 1; i < end; ++i) {
147
148             bool atWordBoundary = false;
149
150             if (i == m_splitter->position()) {
151                 if (m_splitter->boundaryReasons() & QTextBoundaryFinder::StartWord
152                     && m_analysis[i].flags < QScriptAnalysis::TabOrObject)
153                     atWordBoundary = true;
154
155                 m_splitter->toNextBoundary();
156             }
157
158             if (m_analysis[i] == itemAnalysis
159                 && m_analysis[i].flags < QScriptAnalysis::TabOrObject
160                 && !atWordBoundary
161                 && i - start < MaxItemLength)
162                 continue;
163
164             m_items.append(QScriptItem(start, itemAnalysis));
165             start = i;
166             itemAnalysis = m_analysis[start];
167
168             if (atWordBoundary)
169                 itemAnalysis.flags = QScriptAnalysis::Uppercase;
170         }
171         m_items.append(QScriptItem(start, itemAnalysis));
172     }
173
174     void generateScriptItemsSmallCaps(const ushort *uc, int start, int length)
175     {
176         if (!length)
177             return;
178         bool lower = (QChar::category(uc[start]) == QChar::Letter_Lowercase);
179         const int end = start + length;
180         // split text into parts that are already uppercase and parts that are lowercase, and mark the latter to be uppercased later.
181         for (int i = start + 1; i < end; ++i) {
182             bool l = (QChar::category(uc[i]) == QChar::Letter_Lowercase);
183             if ((m_analysis[i] == m_analysis[start])
184                 && m_analysis[i].flags < QScriptAnalysis::TabOrObject
185                 && l == lower
186                 && i - start < MaxItemLength)
187                 continue;
188             m_items.append(QScriptItem(start, m_analysis[start]));
189             if (lower)
190                 m_items.last().analysis.flags = QScriptAnalysis::SmallCaps;
191
192             start = i;
193             lower = l;
194         }
195         m_items.append(QScriptItem(start, m_analysis[start]));
196         if (lower)
197             m_items.last().analysis.flags = QScriptAnalysis::SmallCaps;
198     }
199
200     const QString &m_string;
201     const QScriptAnalysis * const m_analysis;
202     QScriptItemArray &m_items;
203     QTextBoundaryFinder *m_splitter;
204 };
205 }
206
207
208 // ----------------------------------------------------------------------------
209 //
210 // The BiDi algorithm
211 //
212 // ----------------------------------------------------------------------------
213
214 #define BIDI_DEBUG 0
215 #if (BIDI_DEBUG >= 1)
216 QT_BEGIN_INCLUDE_NAMESPACE
217 #include <iostream>
218 QT_END_INCLUDE_NAMESPACE
219 using namespace std;
220
221 static const char *directions[] = {
222     "DirL", "DirR", "DirEN", "DirES", "DirET", "DirAN", "DirCS", "DirB", "DirS", "DirWS", "DirON",
223     "DirLRE", "DirLRO", "DirAL", "DirRLE", "DirRLO", "DirPDF", "DirNSM", "DirBN"
224 };
225
226 #endif
227
228 struct QBidiStatus {
229     QBidiStatus() {
230         eor = QChar::DirON;
231         lastStrong = QChar::DirON;
232         last = QChar:: DirON;
233         dir = QChar::DirON;
234     }
235     QChar::Direction eor;
236     QChar::Direction lastStrong;
237     QChar::Direction last;
238     QChar::Direction dir;
239 };
240
241 enum { MaxBidiLevel = 61 };
242
243 struct QBidiControl {
244     inline QBidiControl(bool rtl)
245         : cCtx(0), base(rtl ? 1 : 0), level(rtl ? 1 : 0), override(false) {}
246
247     inline void embed(bool rtl, bool o = false) {
248         unsigned int toAdd = 1;
249         if((level%2 != 0) == rtl ) {
250             ++toAdd;
251         }
252         if (level + toAdd <= MaxBidiLevel) {
253             ctx[cCtx].level = level;
254             ctx[cCtx].override = override;
255             cCtx++;
256             override = o;
257             level += toAdd;
258         }
259     }
260     inline bool canPop() const { return cCtx != 0; }
261     inline void pdf() {
262         Q_ASSERT(cCtx);
263         --cCtx;
264         level = ctx[cCtx].level;
265         override = ctx[cCtx].override;
266     }
267
268     inline QChar::Direction basicDirection() const {
269         return (base ? QChar::DirR : QChar:: DirL);
270     }
271     inline unsigned int baseLevel() const {
272         return base;
273     }
274     inline QChar::Direction direction() const {
275         return ((level%2) ? QChar::DirR : QChar:: DirL);
276     }
277
278     struct {
279         unsigned int level;
280         bool override;
281     } ctx[MaxBidiLevel];
282     unsigned int cCtx;
283     const unsigned int base;
284     unsigned int level;
285     bool override;
286 };
287
288
289 static void appendItems(QScriptAnalysis *analysis, int &start, int &stop, const QBidiControl &control, QChar::Direction dir)
290 {
291     if (start > stop)
292         return;
293
294     int level = control.level;
295
296     if(dir != QChar::DirON && !control.override) {
297         // add level of run (cases I1 & I2)
298         if(level % 2) {
299             if(dir == QChar::DirL || dir == QChar::DirAN || dir == QChar::DirEN)
300                 level++;
301         } else {
302             if(dir == QChar::DirR)
303                 level++;
304             else if(dir == QChar::DirAN || dir == QChar::DirEN)
305                 level += 2;
306         }
307     }
308
309 #if (BIDI_DEBUG >= 1)
310     qDebug("new run: dir=%s from %d, to %d level = %d override=%d", directions[dir], start, stop, level, control.override);
311 #endif
312     QScriptAnalysis *s = analysis + start;
313     const QScriptAnalysis *e = analysis + stop;
314     while (s <= e) {
315         s->bidiLevel = level;
316         ++s;
317     }
318     ++stop;
319     start = stop;
320 }
321
322 static QChar::Direction skipBoundryNeutrals(QScriptAnalysis *analysis,
323                                             const ushort *unicode, int length,
324                                             int &sor, int &eor, QBidiControl &control)
325 {
326     QChar::Direction dir;
327     int level = sor > 0 ? analysis[sor - 1].bidiLevel : control.level;
328     while (sor < length) {
329         dir = QChar::direction(unicode[sor]);
330         // Keep skipping DirBN as if it doesn't exist
331         if (dir != QChar::DirBN)
332             break;
333         analysis[sor++].bidiLevel = level;
334     }
335
336     eor = sor;
337     if (eor == length)
338         dir = control.basicDirection();
339
340     return dir;
341 }
342
343 // creates the next QScript items.
344 static bool bidiItemize(QTextEngine *engine, QScriptAnalysis *analysis, QBidiControl &control)
345 {
346     bool rightToLeft = (control.basicDirection() == 1);
347     bool hasBidi = rightToLeft;
348 #if BIDI_DEBUG >= 2
349     qDebug() << "bidiItemize: rightToLeft=" << rightToLeft << engine->layoutData->string;
350 #endif
351
352     int sor = 0;
353     int eor = -1;
354
355
356     int length = engine->layoutData->string.length();
357
358     const ushort *unicode = (const ushort *)engine->layoutData->string.unicode();
359     int current = 0;
360
361     QChar::Direction dir = rightToLeft ? QChar::DirR : QChar::DirL;
362     QBidiStatus status;
363
364     QChar::Direction sdir = QChar::direction(*unicode);
365     if (sdir != QChar::DirL && sdir != QChar::DirR && sdir != QChar::DirEN && sdir != QChar::DirAN)
366         sdir = QChar::DirON;
367     else
368         dir = QChar::DirON;
369     status.eor = sdir;
370     status.lastStrong = rightToLeft ? QChar::DirR : QChar::DirL;
371     status.last = status.lastStrong;
372     status.dir = sdir;
373
374
375     while (current <= length) {
376
377         QChar::Direction dirCurrent;
378         if (current == (int)length)
379             dirCurrent = control.basicDirection();
380         else
381             dirCurrent = QChar::direction(unicode[current]);
382
383 #if (BIDI_DEBUG >= 2)
384 //         qDebug() << "pos=" << current << " dir=" << directions[dir]
385 //                  << " current=" << directions[dirCurrent] << " last=" << directions[status.last]
386 //                  << " eor=" << eor << '/' << directions[status.eor]
387 //                  << " sor=" << sor << " lastStrong="
388 //                  << directions[status.lastStrong]
389 //                  << " level=" << (int)control.level << " override=" << (bool)control.override;
390 #endif
391
392         switch(dirCurrent) {
393
394             // embedding and overrides (X1-X9 in the BiDi specs)
395         case QChar::DirRLE:
396         case QChar::DirRLO:
397         case QChar::DirLRE:
398         case QChar::DirLRO:
399             {
400                 bool rtl = (dirCurrent == QChar::DirRLE || dirCurrent == QChar::DirRLO);
401                 hasBidi |= rtl;
402                 bool override = (dirCurrent == QChar::DirLRO || dirCurrent == QChar::DirRLO);
403
404                 unsigned int level = control.level+1;
405                 if ((level%2 != 0) == rtl) ++level;
406                 if(level < MaxBidiLevel) {
407                     eor = current-1;
408                     appendItems(analysis, sor, eor, control, dir);
409                     eor = current;
410                     control.embed(rtl, override);
411                     QChar::Direction edir = (rtl ? QChar::DirR : QChar::DirL);
412                     dir = status.eor = edir;
413                     status.lastStrong = edir;
414                 }
415                 break;
416             }
417         case QChar::DirPDF:
418             {
419                 if (control.canPop()) {
420                     if (dir != control.direction()) {
421                         eor = current-1;
422                         appendItems(analysis, sor, eor, control, dir);
423                         dir = control.direction();
424                     }
425                     eor = current;
426                     appendItems(analysis, sor, eor, control, dir);
427                     control.pdf();
428                     dir = QChar::DirON; status.eor = QChar::DirON;
429                     status.last = control.direction();
430                     if (control.override)
431                         dir = control.direction();
432                     else
433                         dir = QChar::DirON;
434                     status.lastStrong = control.direction();
435                 }
436                 break;
437             }
438
439             // strong types
440         case QChar::DirL:
441             if(dir == QChar::DirON)
442                 dir = QChar::DirL;
443             switch(status.last)
444                 {
445                 case QChar::DirL:
446                     eor = current; status.eor = QChar::DirL; break;
447                 case QChar::DirR:
448                 case QChar::DirAL:
449                 case QChar::DirEN:
450                 case QChar::DirAN:
451                     if (eor >= 0) {
452                         appendItems(analysis, sor, eor, control, dir);
453                         status.eor = dir = skipBoundryNeutrals(analysis, unicode, length, sor, eor, control);
454                     } else {
455                         eor = current; status.eor = dir;
456                     }
457                     break;
458                 case QChar::DirES:
459                 case QChar::DirET:
460                 case QChar::DirCS:
461                 case QChar::DirBN:
462                 case QChar::DirB:
463                 case QChar::DirS:
464                 case QChar::DirWS:
465                 case QChar::DirON:
466                     if(dir != QChar::DirL) {
467                         //last stuff takes embedding dir
468                         if(control.direction() == QChar::DirR) {
469                             if(status.eor != QChar::DirR) {
470                                 // AN or EN
471                                 appendItems(analysis, sor, eor, control, dir);
472                                 status.eor = QChar::DirON;
473                                 dir = QChar::DirR;
474                             }
475                             eor = current - 1;
476                             appendItems(analysis, sor, eor, control, dir);
477                             status.eor = dir = skipBoundryNeutrals(analysis, unicode, length, sor, eor, control);
478                         } else {
479                             if(status.eor != QChar::DirL) {
480                                 appendItems(analysis, sor, eor, control, dir);
481                                 status.eor = QChar::DirON;
482                                 dir = QChar::DirL;
483                             } else {
484                                 eor = current; status.eor = QChar::DirL; break;
485                             }
486                         }
487                     } else {
488                         eor = current; status.eor = QChar::DirL;
489                     }
490                 default:
491                     break;
492                 }
493             status.lastStrong = QChar::DirL;
494             break;
495         case QChar::DirAL:
496         case QChar::DirR:
497             hasBidi = true;
498             if(dir == QChar::DirON) dir = QChar::DirR;
499             switch(status.last)
500                 {
501                 case QChar::DirL:
502                 case QChar::DirEN:
503                 case QChar::DirAN:
504                     if (eor >= 0)
505                         appendItems(analysis, sor, eor, control, dir);
506                     // fall through
507                 case QChar::DirR:
508                 case QChar::DirAL:
509                     dir = QChar::DirR; eor = current; status.eor = QChar::DirR; break;
510                 case QChar::DirES:
511                 case QChar::DirET:
512                 case QChar::DirCS:
513                 case QChar::DirBN:
514                 case QChar::DirB:
515                 case QChar::DirS:
516                 case QChar::DirWS:
517                 case QChar::DirON:
518                     if(status.eor != QChar::DirR && status.eor != QChar::DirAL) {
519                         //last stuff takes embedding dir
520                         if(control.direction() == QChar::DirR
521                            || status.lastStrong == QChar::DirR || status.lastStrong == QChar::DirAL) {
522                             appendItems(analysis, sor, eor, control, dir);
523                             dir = QChar::DirR; status.eor = QChar::DirON;
524                             eor = current;
525                         } else {
526                             eor = current - 1;
527                             appendItems(analysis, sor, eor, control, dir);
528                             dir = QChar::DirR; status.eor = QChar::DirON;
529                         }
530                     } else {
531                         eor = current; status.eor = QChar::DirR;
532                     }
533                 default:
534                     break;
535                 }
536             status.lastStrong = dirCurrent;
537             break;
538
539             // weak types:
540
541         case QChar::DirNSM:
542             if (eor == current-1)
543                 eor = current;
544             break;
545         case QChar::DirEN:
546             // if last strong was AL change EN to AN
547             if(status.lastStrong != QChar::DirAL) {
548                 if(dir == QChar::DirON) {
549                     if(status.lastStrong == QChar::DirL)
550                         dir = QChar::DirL;
551                     else
552                         dir = QChar::DirEN;
553                 }
554                 switch(status.last)
555                     {
556                     case QChar::DirET:
557                         if (status.lastStrong == QChar::DirR || status.lastStrong == QChar::DirAL) {
558                             appendItems(analysis, sor, eor, control, dir);
559                             status.eor = QChar::DirON;
560                             dir = QChar::DirAN;
561                         }
562                         // fall through
563                     case QChar::DirEN:
564                     case QChar::DirL:
565                         eor = current;
566                         status.eor = dirCurrent;
567                         break;
568                     case QChar::DirR:
569                     case QChar::DirAL:
570                     case QChar::DirAN:
571                         if (eor >= 0)
572                             appendItems(analysis, sor, eor, control, dir);
573                         else
574                             eor = current;
575                         status.eor = QChar::DirEN;
576                         dir = QChar::DirAN; break;
577                     case QChar::DirES:
578                     case QChar::DirCS:
579                         if(status.eor == QChar::DirEN || dir == QChar::DirAN) {
580                             eor = current; break;
581                         }
582                     case QChar::DirBN:
583                     case QChar::DirB:
584                     case QChar::DirS:
585                     case QChar::DirWS:
586                     case QChar::DirON:
587                         if(status.eor == QChar::DirR) {
588                             // neutrals go to R
589                             eor = current - 1;
590                             appendItems(analysis, sor, eor, control, dir);
591                             dir = QChar::DirON; status.eor = QChar::DirEN;
592                             dir = QChar::DirAN;
593                         }
594                         else if(status.eor == QChar::DirL ||
595                                  (status.eor == QChar::DirEN && status.lastStrong == QChar::DirL)) {
596                             eor = current; status.eor = dirCurrent;
597                         } else {
598                             // numbers on both sides, neutrals get right to left direction
599                             if(dir != QChar::DirL) {
600                                 appendItems(analysis, sor, eor, control, dir);
601                                 dir = QChar::DirON; status.eor = QChar::DirON;
602                                 eor = current - 1;
603                                 dir = QChar::DirR;
604                                 appendItems(analysis, sor, eor, control, dir);
605                                 dir = QChar::DirON; status.eor = QChar::DirON;
606                                 dir = QChar::DirAN;
607                             } else {
608                                 eor = current; status.eor = dirCurrent;
609                             }
610                         }
611                     default:
612                         break;
613                     }
614                 break;
615             }
616         case QChar::DirAN:
617             hasBidi = true;
618             dirCurrent = QChar::DirAN;
619             if(dir == QChar::DirON) dir = QChar::DirAN;
620             switch(status.last)
621                 {
622                 case QChar::DirL:
623                 case QChar::DirAN:
624                     eor = current; status.eor = QChar::DirAN; break;
625                 case QChar::DirR:
626                 case QChar::DirAL:
627                 case QChar::DirEN:
628                     if (eor >= 0){
629                         appendItems(analysis, sor, eor, control, dir);
630                     } else {
631                         eor = current;
632                     }
633                     dir = QChar::DirAN; status.eor = QChar::DirAN;
634                     break;
635                 case QChar::DirCS:
636                     if(status.eor == QChar::DirAN) {
637                         eor = current; break;
638                     }
639                 case QChar::DirES:
640                 case QChar::DirET:
641                 case QChar::DirBN:
642                 case QChar::DirB:
643                 case QChar::DirS:
644                 case QChar::DirWS:
645                 case QChar::DirON:
646                     if(status.eor == QChar::DirR) {
647                         // neutrals go to R
648                         eor = current - 1;
649                         appendItems(analysis, sor, eor, control, dir);
650                         status.eor = QChar::DirAN;
651                         dir = QChar::DirAN;
652                     } else if(status.eor == QChar::DirL ||
653                                (status.eor == QChar::DirEN && status.lastStrong == QChar::DirL)) {
654                         eor = current; status.eor = dirCurrent;
655                     } else {
656                         // numbers on both sides, neutrals get right to left direction
657                         if(dir != QChar::DirL) {
658                             appendItems(analysis, sor, eor, control, dir);
659                             status.eor = QChar::DirON;
660                             eor = current - 1;
661                             dir = QChar::DirR;
662                             appendItems(analysis, sor, eor, control, dir);
663                             status.eor = QChar::DirAN;
664                             dir = QChar::DirAN;
665                         } else {
666                             eor = current; status.eor = dirCurrent;
667                         }
668                     }
669                 default:
670                     break;
671                 }
672             break;
673         case QChar::DirES:
674         case QChar::DirCS:
675             break;
676         case QChar::DirET:
677             if(status.last == QChar::DirEN) {
678                 dirCurrent = QChar::DirEN;
679                 eor = current; status.eor = dirCurrent;
680             }
681             break;
682
683             // boundary neutrals should be ignored
684         case QChar::DirBN:
685             break;
686             // neutrals
687         case QChar::DirB:
688             // ### what do we do with newline and paragraph separators that come to here?
689             break;
690         case QChar::DirS:
691             // ### implement rule L1
692             break;
693         case QChar::DirWS:
694         case QChar::DirON:
695             break;
696         default:
697             break;
698         }
699
700         //qDebug() << "     after: dir=" << //        dir << " current=" << dirCurrent << " last=" << status.last << " eor=" << status.eor << " lastStrong=" << status.lastStrong << " embedding=" << control.direction();
701
702         if(current >= (int)length) break;
703
704         // set status.last as needed.
705         switch(dirCurrent) {
706         case QChar::DirET:
707         case QChar::DirES:
708         case QChar::DirCS:
709         case QChar::DirS:
710         case QChar::DirWS:
711         case QChar::DirON:
712             switch(status.last)
713             {
714             case QChar::DirL:
715             case QChar::DirR:
716             case QChar::DirAL:
717             case QChar::DirEN:
718             case QChar::DirAN:
719                 status.last = dirCurrent;
720                 break;
721             default:
722                 status.last = QChar::DirON;
723             }
724             break;
725         case QChar::DirNSM:
726         case QChar::DirBN:
727             // ignore these
728             break;
729         case QChar::DirLRO:
730         case QChar::DirLRE:
731             status.last = QChar::DirL;
732             break;
733         case QChar::DirRLO:
734         case QChar::DirRLE:
735             status.last = QChar::DirR;
736             break;
737         case QChar::DirEN:
738             if (status.last == QChar::DirL) {
739                 status.last = QChar::DirL;
740                 break;
741             }
742             // fall through
743         default:
744             status.last = dirCurrent;
745         }
746
747         ++current;
748     }
749
750 #if (BIDI_DEBUG >= 1)
751     qDebug() << "reached end of line current=" << current << ", eor=" << eor;
752 #endif
753     eor = current - 1; // remove dummy char
754
755     if (sor <= eor)
756         appendItems(analysis, sor, eor, control, dir);
757
758     return hasBidi;
759 }
760
761 void QTextEngine::bidiReorder(int numItems, const quint8 *levels, int *visualOrder)
762 {
763
764     // first find highest and lowest levels
765     quint8 levelLow = 128;
766     quint8 levelHigh = 0;
767     int i = 0;
768     while (i < numItems) {
769         //printf("level = %d\n", r->level);
770         if (levels[i] > levelHigh)
771             levelHigh = levels[i];
772         if (levels[i] < levelLow)
773             levelLow = levels[i];
774         i++;
775     }
776
777     // implements reordering of the line (L2 according to BiDi spec):
778     // L2. From the highest level found in the text to the lowest odd level on each line,
779     // reverse any contiguous sequence of characters that are at that level or higher.
780
781     // reversing is only done up to the lowest odd level
782     if(!(levelLow%2)) levelLow++;
783
784 #if (BIDI_DEBUG >= 1)
785 //     qDebug() << "reorderLine: lineLow = " << (uint)levelLow << ", lineHigh = " << (uint)levelHigh;
786 #endif
787
788     int count = numItems - 1;
789     for (i = 0; i < numItems; i++)
790         visualOrder[i] = i;
791
792     while(levelHigh >= levelLow) {
793         int i = 0;
794         while (i < count) {
795             while(i < count && levels[i] < levelHigh) i++;
796             int start = i;
797             while(i <= count && levels[i] >= levelHigh) i++;
798             int end = i-1;
799
800             if(start != end) {
801                 //qDebug() << "reversing from " << start << " to " << end;
802                 for(int j = 0; j < (end-start+1)/2; j++) {
803                     int tmp = visualOrder[start+j];
804                     visualOrder[start+j] = visualOrder[end-j];
805                     visualOrder[end-j] = tmp;
806                 }
807             }
808             i++;
809         }
810         levelHigh--;
811     }
812
813 #if (BIDI_DEBUG >= 1)
814 //     qDebug() << "visual order is:";
815 //     for (i = 0; i < numItems; i++)
816 //         qDebug() << visualOrder[i];
817 #endif
818 }
819
820 QT_BEGIN_INCLUDE_NAMESPACE
821
822 #if defined(Q_WS_X11) || defined (Q_WS_QWS)
823 #   include "qfontengine_ft_p.h"
824 #elif defined(Q_WS_MAC)
825 # include "qtextengine_mac.cpp"
826 #endif
827
828 #include <private/qharfbuzz_p.h>
829
830 QT_END_INCLUDE_NAMESPACE
831
832 // ask the font engine to find out which glyphs (as an index in the specific font) to use for the text in one item.
833 static bool stringToGlyphs(HB_ShaperItem *item, QGlyphLayout *glyphs, QFontEngine *fontEngine)
834 {
835     int nGlyphs = item->num_glyphs;
836
837     QTextEngine::ShaperFlags shaperFlags(QTextEngine::GlyphIndicesOnly);
838     if (item->item.bidiLevel % 2)
839         shaperFlags |= QTextEngine::RightToLeft;
840
841     bool result = fontEngine->stringToCMap(reinterpret_cast<const QChar *>(item->string + item->item.pos), item->item.length, glyphs, &nGlyphs, shaperFlags);
842     item->num_glyphs = nGlyphs;
843     glyphs->numGlyphs = nGlyphs;
844     return result;
845 }
846
847 // shape all the items that intersect with the line, taking tab widths into account to find out what text actually fits in the line.
848 void QTextEngine::shapeLine(const QScriptLine &line)
849 {
850     QFixed x;
851     bool first = true;
852     const int end = findItem(line.from + line.length - 1);
853     int item = findItem(line.from);
854     if (item == -1)
855         return;
856     for (item = findItem(line.from); item <= end; ++item) {
857         QScriptItem &si = layoutData->items[item];
858         if (si.analysis.flags == QScriptAnalysis::Tab) {
859             ensureSpace(1);
860             si.width = calculateTabWidth(item, x);
861         } else {
862             shape(item);
863         }
864         if (first && si.position != line.from) { // that means our x position has to be offset
865             QGlyphLayout glyphs = shapedGlyphs(&si);
866             Q_ASSERT(line.from > si.position);
867             for (int i = line.from - si.position - 1; i >= 0; i--) {
868                 x -= glyphs.effectiveAdvance(i);
869             }
870         }
871         first = false;
872
873         x += si.width;
874     }
875 }
876
877 #if !defined(QT_ENABLE_HARFBUZZ_FOR_MAC) && defined(Q_WS_MAC)
878 static bool enableHarfBuzz()
879 {
880     static enum { Yes, No, Unknown } status = Unknown;
881
882     if (status == Unknown) {
883         QByteArray v = qgetenv("QT_ENABLE_HARFBUZZ");
884         bool value = !v.isEmpty() && v != "0" && v != "false";
885         if (value) status = Yes;
886         else status = No;
887     }
888     return status == Yes;
889 }
890 #endif
891
892 void QTextEngine::shapeText(int item) const
893 {
894     Q_ASSERT(item < layoutData->items.size());
895     QScriptItem &si = layoutData->items[item];
896
897     if (si.num_glyphs)
898         return;
899
900 #if defined(Q_WS_MAC)
901 #if !defined(QT_ENABLE_HARFBUZZ_FOR_MAC)
902     if (enableHarfBuzz()) {
903 #endif
904         QFontEngine *actualFontEngine = fontEngine(si, &si.ascent, &si.descent, &si.leading);
905         if (actualFontEngine->type() == QFontEngine::Multi)
906             actualFontEngine = static_cast<QFontEngineMulti *>(actualFontEngine)->engine(0);
907
908         HB_Face face = actualFontEngine->harfbuzzFace();
909         HB_Script script = (HB_Script) si.analysis.script;
910         if (face->supported_scripts[script])
911             shapeTextWithHarfbuzz(item);
912         else
913             shapeTextMac(item);
914 #if !defined(QT_ENABLE_HARFBUZZ_FOR_MAC)
915     } else {
916         shapeTextMac(item);
917     }
918 #endif
919 #elif defined(Q_WS_WINCE)
920     shapeTextWithCE(item);
921 #else
922     shapeTextWithHarfbuzz(item);
923 #endif
924
925     si.width = 0;
926
927     if (!si.num_glyphs)
928         return;
929     QGlyphLayout glyphs = shapedGlyphs(&si);
930
931     QFont font = this->font(si);
932     bool letterSpacingIsAbsolute = font.d->letterSpacingIsAbsolute;
933     QFixed letterSpacing = font.d->letterSpacing;
934     QFixed wordSpacing = font.d->wordSpacing;
935
936     if (letterSpacingIsAbsolute && letterSpacing.value())
937         letterSpacing *= font.d->dpi / qt_defaultDpiY();
938
939     if (letterSpacing != 0) {
940         for (int i = 1; i < si.num_glyphs; ++i) {
941             if (glyphs.attributes[i].clusterStart) {
942                 if (letterSpacingIsAbsolute)
943                     glyphs.advances_x[i-1] += letterSpacing;
944                 else {
945                     QFixed &advance = glyphs.advances_x[i-1];
946                     advance += (letterSpacing - 100) * advance / 100;
947                 }
948             }
949         }
950         if (letterSpacingIsAbsolute)
951             glyphs.advances_x[si.num_glyphs-1] += letterSpacing;
952         else {
953             QFixed &advance = glyphs.advances_x[si.num_glyphs-1];
954             advance += (letterSpacing - 100) * advance / 100;
955         }
956     }
957     if (wordSpacing != 0) {
958         for (int i = 0; i < si.num_glyphs; ++i) {
959             if (glyphs.attributes[i].justification == HB_Space
960                 || glyphs.attributes[i].justification == HB_Arabic_Space) {
961                 // word spacing only gets added once to a consecutive run of spaces (see CSS spec)
962                 if (i + 1 == si.num_glyphs
963                     ||(glyphs.attributes[i+1].justification != HB_Space
964                        && glyphs.attributes[i+1].justification != HB_Arabic_Space))
965                     glyphs.advances_x[i] += wordSpacing;
966             }
967         }
968     }
969
970     for (int i = 0; i < si.num_glyphs; ++i)
971         si.width += glyphs.advances_x[i];
972 }
973
974 static inline bool hasCaseChange(const QScriptItem &si)
975 {
976     return si.analysis.flags == QScriptAnalysis::SmallCaps ||
977            si.analysis.flags == QScriptAnalysis::Uppercase ||
978            si.analysis.flags == QScriptAnalysis::Lowercase;
979 }
980
981 #if defined(Q_WS_WINCE) //TODO
982 // set the glyph attributes heuristically. Assumes a 1 to 1 relationship between chars and glyphs
983 // and no reordering.
984 // also computes logClusters heuristically
985 static void heuristicSetGlyphAttributes(const QChar *uc, int length, QGlyphLayout *glyphs, unsigned short *logClusters, int num_glyphs)
986 {
987     // ### zeroWidth and justification are missing here!!!!!
988
989     Q_UNUSED(num_glyphs);
990     Q_ASSERT(num_glyphs <= length);
991
992 //     qDebug("QScriptEngine::heuristicSetGlyphAttributes, num_glyphs=%d", item->num_glyphs);
993
994     int glyph_pos = 0;
995     for (int i = 0; i < length; i++) {
996         if (uc[i].unicode() >= 0xd800 && uc[i].unicode() < 0xdc00 && i < length-1
997             && uc[i+1].unicode() >= 0xdc00 && uc[i+1].unicode() < 0xe000) {
998             logClusters[i] = glyph_pos;
999             logClusters[++i] = glyph_pos;
1000         } else {
1001             logClusters[i] = glyph_pos;
1002         }
1003         ++glyph_pos;
1004     }
1005
1006     // first char in a run is never (treated as) a mark
1007     int cStart = 0;
1008
1009     const bool symbolFont = false; // ####
1010     glyphs->attributes[0].mark = false;
1011     glyphs->attributes[0].clusterStart = true;
1012     glyphs->attributes[0].dontPrint = (!symbolFont && uc[0].unicode() == 0x00ad) || qIsControlChar(uc[0].unicode());
1013
1014     int pos = 0;
1015     int lastCat = QChar::category(uc[0].unicode());
1016     for (int i = 1; i < length; ++i) {
1017         if (logClusters[i] == pos)
1018             // same glyph
1019             continue;
1020         ++pos;
1021         while (pos < logClusters[i]) {
1022             glyphs[pos].attributes = glyphs[pos-1].attributes;
1023             ++pos;
1024         }
1025         // hide soft-hyphens by default
1026         if ((!symbolFont && uc[i].unicode() == 0x00ad) || qIsControlChar(uc[i].unicode()))
1027             glyphs->attributes[pos].dontPrint = true;
1028         const QUnicodeTables::Properties *prop = QUnicodeTables::properties(uc[i].unicode());
1029         int cat = prop->category;
1030         if (cat != QChar::Mark_NonSpacing) {
1031             glyphs->attributes[pos].mark = false;
1032             glyphs->attributes[pos].clusterStart = true;
1033             glyphs->attributes[pos].combiningClass = 0;
1034             cStart = logClusters[i];
1035         } else {
1036             int cmb = prop->combiningClass;
1037
1038             if (cmb == 0) {
1039                 // Fix 0 combining classes
1040                 if ((uc[pos].unicode() & 0xff00) == 0x0e00) {
1041                     // thai or lao
1042                     unsigned char col = uc[pos].cell();
1043                     if (col == 0x31 ||
1044                          col == 0x34 ||
1045                          col == 0x35 ||
1046                          col == 0x36 ||
1047                          col == 0x37 ||
1048                          col == 0x47 ||
1049                          col == 0x4c ||
1050                          col == 0x4d ||
1051                          col == 0x4e) {
1052                         cmb = QChar::Combining_AboveRight;
1053                     } else if (col == 0xb1 ||
1054                                 col == 0xb4 ||
1055                                 col == 0xb5 ||
1056                                 col == 0xb6 ||
1057                                 col == 0xb7 ||
1058                                 col == 0xbb ||
1059                                 col == 0xcc ||
1060                                 col == 0xcd) {
1061                         cmb = QChar::Combining_Above;
1062                     } else if (col == 0xbc) {
1063                         cmb = QChar::Combining_Below;
1064                     }
1065                 }
1066             }
1067
1068             glyphs->attributes[pos].mark = true;
1069             glyphs->attributes[pos].clusterStart = false;
1070             glyphs->attributes[pos].combiningClass = cmb;
1071             logClusters[i] = cStart;
1072             glyphs->advances_x[pos] = 0;
1073             glyphs->advances_y[pos] = 0;
1074         }
1075
1076         // one gets an inter character justification point if the current char is not a non spacing mark.
1077         // as then the current char belongs to the last one and one gets a space justification point
1078         // after the space char.
1079         if (lastCat == QChar::Separator_Space)
1080             glyphs->attributes[pos-1].justification = HB_Space;
1081         else if (cat != QChar::Mark_NonSpacing)
1082             glyphs->attributes[pos-1].justification = HB_Character;
1083         else
1084             glyphs->attributes[pos-1].justification = HB_NoJustification;
1085
1086         lastCat = cat;
1087     }
1088     pos = logClusters[length-1];
1089     if (lastCat == QChar::Separator_Space)
1090         glyphs->attributes[pos].justification = HB_Space;
1091     else
1092         glyphs->attributes[pos].justification = HB_Character;
1093 }
1094
1095 void QTextEngine::shapeTextWithCE(int item) const
1096 {
1097     QScriptItem &si = layoutData->items[item];
1098     si.glyph_data_offset = layoutData->used;
1099
1100     QFontEngine *fe = fontEngine(si, &si.ascent, &si.descent, &si.leading);
1101
1102     QTextEngine::ShaperFlags flags;
1103     if (si.analysis.bidiLevel % 2)
1104         flags |= RightToLeft;
1105     if (option.useDesignMetrics())
1106         flags |= DesignMetrics;
1107
1108     // pre-initialize char attributes
1109     if (! attributes())
1110         return;
1111
1112     const int len = length(item);
1113     int num_glyphs = length(item);
1114     const QChar *str = layoutData->string.unicode() + si.position;
1115     ushort upperCased[256];
1116     if (hasCaseChange(si)) {
1117         ushort *uc = upperCased;
1118         if (len > 256)
1119             uc = new ushort[len];
1120         for (int i = 0; i < len; ++i) {
1121             if(si.analysis.flags == QScriptAnalysis::Lowercase)
1122                 uc[i] = str[i].toLower().unicode();
1123             else
1124                 uc[i] = str[i].toUpper().unicode();
1125         }
1126         str = reinterpret_cast<const QChar *>(uc);
1127     }
1128
1129     while (true) {
1130         if (! ensureSpace(num_glyphs)) {
1131             // If str is converted to uppercase/lowercase form with a new buffer,
1132             // we need to delete that buffer before return for error
1133             const ushort *uc = reinterpret_cast<const ushort *>(str);
1134             if (hasCaseChange(si) && uc != upperCased)
1135                 delete [] uc;
1136             return;
1137         }
1138         num_glyphs = layoutData->glyphLayout.numGlyphs - layoutData->used;
1139
1140         QGlyphLayout g = availableGlyphs(&si);
1141         unsigned short *log_clusters = logClusters(&si);
1142
1143         if (fe->stringToCMap(str,
1144                              len,
1145                              &g,
1146                              &num_glyphs,
1147                              flags)) {
1148             heuristicSetGlyphAttributes(str, len, &g, log_clusters, num_glyphs);
1149                     break;
1150         }
1151     }
1152
1153     si.num_glyphs = num_glyphs;
1154
1155     layoutData->used += si.num_glyphs;
1156
1157     const ushort *uc = reinterpret_cast<const ushort *>(str);
1158     if (hasCaseChange(si) && uc != upperCased)
1159         delete [] uc;
1160 }
1161 #endif
1162
1163 static inline void moveGlyphData(const QGlyphLayout &destination, const QGlyphLayout &source, int num)
1164 {
1165     if (num > 0 && destination.glyphs != source.glyphs) {
1166         memmove(destination.glyphs, source.glyphs, num * sizeof(HB_Glyph));
1167         memmove(destination.attributes, source.attributes, num * sizeof(HB_GlyphAttributes));
1168         memmove(destination.advances_x, source.advances_x, num * sizeof(HB_Fixed));
1169         memmove(destination.offsets, source.offsets, num * sizeof(HB_FixedPoint));
1170     }
1171 }
1172
1173 /// take the item from layoutData->items and
1174 void QTextEngine::shapeTextWithHarfbuzz(int item) const
1175 {
1176     Q_ASSERT(sizeof(HB_Fixed) == sizeof(QFixed));
1177     Q_ASSERT(sizeof(HB_FixedPoint) == sizeof(QFixedPoint));
1178
1179     QScriptItem &si = layoutData->items[item];
1180
1181     si.glyph_data_offset = layoutData->used;
1182
1183     QFontEngine *font = fontEngine(si, &si.ascent, &si.descent, &si.leading);
1184
1185     bool kerningEnabled = this->font(si).d->kerning;
1186
1187     HB_ShaperItem entire_shaper_item;
1188     qMemSet(&entire_shaper_item, 0, sizeof(entire_shaper_item));
1189     entire_shaper_item.string = reinterpret_cast<const HB_UChar16 *>(layoutData->string.constData());
1190     entire_shaper_item.stringLength = layoutData->string.length();
1191     entire_shaper_item.item.script = (HB_Script)si.analysis.script;
1192     entire_shaper_item.item.pos = si.position;
1193     entire_shaper_item.item.length = length(item);
1194     entire_shaper_item.item.bidiLevel = si.analysis.bidiLevel;
1195
1196     HB_UChar16 upperCased[256]; // XXX what about making this 4096, so we don't have to extend it ever.
1197     if (hasCaseChange(si)) {
1198         HB_UChar16 *uc = upperCased;
1199         if (entire_shaper_item.item.length > 256)
1200             uc = new HB_UChar16[entire_shaper_item.item.length];
1201         for (uint i = 0; i < entire_shaper_item.item.length; ++i) {
1202             if(si.analysis.flags == QScriptAnalysis::Lowercase)
1203                 uc[i] = QChar::toLower(entire_shaper_item.string[si.position + i]);
1204             else
1205                 uc[i] = QChar::toUpper(entire_shaper_item.string[si.position + i]);
1206         }
1207         entire_shaper_item.item.pos = 0;
1208         entire_shaper_item.string = uc;
1209         entire_shaper_item.stringLength = entire_shaper_item.item.length;
1210     }
1211
1212     entire_shaper_item.shaperFlags = 0;
1213     if (!kerningEnabled)
1214         entire_shaper_item.shaperFlags |= HB_ShaperFlag_NoKerning;
1215     if (option.useDesignMetrics())
1216         entire_shaper_item.shaperFlags |= HB_ShaperFlag_UseDesignMetrics;
1217
1218     entire_shaper_item.num_glyphs = qMax(layoutData->glyphLayout.numGlyphs - layoutData->used, int(entire_shaper_item.item.length));
1219     if (! ensureSpace(entire_shaper_item.num_glyphs)) {
1220         if (hasCaseChange(si))
1221             delete [] const_cast<HB_UChar16 *>(entire_shaper_item.string);
1222         return;
1223     }
1224     QGlyphLayout initialGlyphs = availableGlyphs(&si).mid(0, entire_shaper_item.num_glyphs);
1225
1226     if (!stringToGlyphs(&entire_shaper_item, &initialGlyphs, font)) {
1227         if (! ensureSpace(entire_shaper_item.num_glyphs)) {
1228             if (hasCaseChange(si))
1229                 delete [] const_cast<HB_UChar16 *>(entire_shaper_item.string);
1230             return;
1231         }
1232         initialGlyphs = availableGlyphs(&si).mid(0, entire_shaper_item.num_glyphs);
1233
1234         if (!stringToGlyphs(&entire_shaper_item, &initialGlyphs, font)) {
1235             // ############ if this happens there's a bug in the fontengine
1236             if (hasCaseChange(si) && entire_shaper_item.string != upperCased)
1237                 delete [] const_cast<HB_UChar16 *>(entire_shaper_item.string);
1238             return;
1239         }
1240     }
1241
1242     // split up the item into parts that come from different font engines.
1243     QVarLengthArray<int> itemBoundaries(2);
1244     // k * 2 entries, array[k] == index in string, array[k + 1] == index in glyphs
1245     itemBoundaries[0] = entire_shaper_item.item.pos;
1246     itemBoundaries[1] = 0;
1247
1248     if (font->type() == QFontEngine::Multi) {
1249         uint lastEngine = 0;
1250         int charIdx = entire_shaper_item.item.pos;
1251         const int stringEnd = charIdx + entire_shaper_item.item.length;
1252         for (quint32 i = 0; i < entire_shaper_item.num_glyphs; ++i, ++charIdx) {
1253             uint engineIdx = initialGlyphs.glyphs[i] >> 24;
1254             if (engineIdx != lastEngine && i > 0) {
1255                 itemBoundaries.append(charIdx);
1256                 itemBoundaries.append(i);
1257             }
1258             lastEngine = engineIdx;
1259             if (HB_IsHighSurrogate(entire_shaper_item.string[charIdx])
1260                 && charIdx < stringEnd - 1
1261                 && HB_IsLowSurrogate(entire_shaper_item.string[charIdx + 1]))
1262                 ++charIdx;
1263         }
1264     }
1265
1266
1267
1268     int remaining_glyphs = entire_shaper_item.num_glyphs;
1269     int glyph_pos = 0;
1270     // for each item shape using harfbuzz and store the results in our layoutData's glyphs array.
1271     for (int k = 0; k < itemBoundaries.size(); k += 2) { // for the +2, see the comment at the definition of itemBoundaries
1272
1273         HB_ShaperItem shaper_item = entire_shaper_item;
1274
1275         shaper_item.item.pos = itemBoundaries[k];
1276         if (k < itemBoundaries.size() - 3) {
1277             shaper_item.item.length = itemBoundaries[k + 2] - shaper_item.item.pos;
1278             shaper_item.num_glyphs = itemBoundaries[k + 3] - itemBoundaries[k + 1];
1279         } else { // last combo in the list, avoid out of bounds access.
1280             shaper_item.item.length -= shaper_item.item.pos - entire_shaper_item.item.pos;
1281             shaper_item.num_glyphs -= itemBoundaries[k + 1];
1282         }
1283         shaper_item.initialGlyphCount = shaper_item.num_glyphs;
1284         if (shaper_item.num_glyphs < shaper_item.item.length)
1285             shaper_item.num_glyphs = shaper_item.item.length;
1286
1287         QFontEngine *actualFontEngine = font;
1288         uint engineIdx = 0;
1289         if (font->type() == QFontEngine::Multi) {
1290             engineIdx = uint(availableGlyphs(&si).glyphs[glyph_pos] >> 24);
1291
1292             actualFontEngine = static_cast<QFontEngineMulti *>(font)->engine(engineIdx);
1293         }
1294
1295         si.ascent = qMax(actualFontEngine->ascent(), si.ascent);
1296         si.descent = qMax(actualFontEngine->descent(), si.descent);
1297         si.leading = qMax(actualFontEngine->leading(), si.leading);
1298
1299         shaper_item.font = actualFontEngine->harfbuzzFont();
1300         shaper_item.face = actualFontEngine->harfbuzzFace();
1301
1302         shaper_item.glyphIndicesPresent = true;
1303
1304         remaining_glyphs -= shaper_item.initialGlyphCount;
1305
1306         do {
1307             if (! ensureSpace(glyph_pos + shaper_item.num_glyphs + remaining_glyphs)) {
1308                 if (hasCaseChange(si))
1309                     delete [] const_cast<HB_UChar16 *>(entire_shaper_item.string);
1310                 return;
1311             }
1312
1313             const QGlyphLayout g = availableGlyphs(&si).mid(glyph_pos);
1314             if (shaper_item.num_glyphs > shaper_item.item.length)
1315                 moveGlyphData(g.mid(shaper_item.num_glyphs), g.mid(shaper_item.initialGlyphCount), remaining_glyphs);
1316
1317             shaper_item.glyphs = g.glyphs;
1318             shaper_item.attributes = g.attributes;
1319             shaper_item.advances = reinterpret_cast<HB_Fixed *>(g.advances_x);
1320             shaper_item.offsets = reinterpret_cast<HB_FixedPoint *>(g.offsets);
1321
1322             if (shaper_item.glyphIndicesPresent) {
1323                 for (hb_uint32 i = 0; i < shaper_item.initialGlyphCount; ++i)
1324                     shaper_item.glyphs[i] &= 0x00ffffff;
1325             }
1326
1327             shaper_item.log_clusters = logClusters(&si) + shaper_item.item.pos - entire_shaper_item.item.pos;
1328
1329 //          qDebug("    .. num_glyphs=%d, used=%d, item.num_glyphs=%d", num_glyphs, used, shaper_item.num_glyphs);
1330         } while (!qShapeItem(&shaper_item)); // this does the actual shaping via harfbuzz.
1331
1332         QGlyphLayout g = availableGlyphs(&si).mid(glyph_pos, shaper_item.num_glyphs);
1333         moveGlyphData(g.mid(shaper_item.num_glyphs), g.mid(shaper_item.initialGlyphCount), remaining_glyphs);
1334
1335         for (hb_uint32 i = 0; i < shaper_item.num_glyphs; ++i)
1336             g.glyphs[i] = g.glyphs[i] | (engineIdx << 24);
1337
1338         for (hb_uint32 i = 0; i < shaper_item.item.length; ++i)
1339             shaper_item.log_clusters[i] += glyph_pos;
1340
1341         if (kerningEnabled && !shaper_item.kerning_applied)
1342             font->doKerning(&g, option.useDesignMetrics() ? QFlag(QTextEngine::DesignMetrics) : QFlag(0));
1343
1344         glyph_pos += shaper_item.num_glyphs;
1345     }
1346
1347 //     qDebug("    -> item: script=%d num_glyphs=%d", shaper_item.script, shaper_item.num_glyphs);
1348     si.num_glyphs = glyph_pos;
1349
1350     layoutData->used += si.num_glyphs;
1351
1352     if (hasCaseChange(si) && entire_shaper_item.string != upperCased)
1353         delete [] const_cast<HB_UChar16 *>(entire_shaper_item.string);
1354 }
1355
1356 static void init(QTextEngine *e)
1357 {
1358     e->ignoreBidi = false;
1359     e->cacheGlyphs = false;
1360     e->forceJustification = false;
1361     e->visualMovement = false;
1362
1363     e->layoutData = 0;
1364
1365     e->minWidth = 0;
1366     e->maxWidth = 0;
1367
1368     e->underlinePositions = 0;
1369     e->specialData = 0;
1370     e->stackEngine = false;
1371 }
1372
1373 QTextEngine::QTextEngine()
1374 {
1375     init(this);
1376 }
1377
1378 QTextEngine::QTextEngine(const QString &str, const QFont &f)
1379     : text(str),
1380       fnt(f)
1381 {
1382     init(this);
1383 }
1384
1385 QTextEngine::~QTextEngine()
1386 {
1387     if (!stackEngine)
1388         delete layoutData;
1389     delete specialData;
1390 }
1391
1392 const HB_CharAttributes *QTextEngine::attributes() const
1393 {
1394     if (layoutData && layoutData->haveCharAttributes)
1395         return (HB_CharAttributes *) layoutData->memory;
1396
1397     itemize();
1398     if (! ensureSpace(layoutData->string.length()))
1399         return NULL;
1400
1401     QVarLengthArray<HB_ScriptItem> hbScriptItems(layoutData->items.size());
1402
1403     for (int i = 0; i < layoutData->items.size(); ++i) {
1404         const QScriptItem &si = layoutData->items[i];
1405         hbScriptItems[i].pos = si.position;
1406         hbScriptItems[i].length = length(i);
1407         hbScriptItems[i].bidiLevel = si.analysis.bidiLevel;
1408         hbScriptItems[i].script = (HB_Script)si.analysis.script;
1409     }
1410
1411     qGetCharAttributes(reinterpret_cast<const HB_UChar16 *>(layoutData->string.constData()),
1412                        layoutData->string.length(),
1413                        hbScriptItems.data(), hbScriptItems.size(),
1414                        (HB_CharAttributes *)layoutData->memory);
1415
1416
1417     layoutData->haveCharAttributes = true;
1418     return (HB_CharAttributes *) layoutData->memory;
1419 }
1420
1421 void QTextEngine::shape(int item) const
1422 {
1423     if (layoutData->items[item].analysis.flags == QScriptAnalysis::Object) {
1424         ensureSpace(1);
1425         if (block.docHandle()) {
1426             QTextFormat format = formats()->format(formatIndex(&layoutData->items[item]));
1427             docLayout()->resizeInlineObject(QTextInlineObject(item, const_cast<QTextEngine *>(this)),
1428                                             layoutData->items[item].position + block.position(), format);
1429         }
1430     } else if (layoutData->items[item].analysis.flags == QScriptAnalysis::Tab) {
1431         // set up at least the ascent/descent/leading of the script item for the tab
1432         fontEngine(layoutData->items[item],
1433                    &layoutData->items[item].ascent,
1434                    &layoutData->items[item].descent,
1435                    &layoutData->items[item].leading);
1436     } else {
1437         shapeText(item);
1438     }
1439 }
1440
1441 static inline void releaseCachedFontEngine(QFontEngine *fontEngine)
1442 {
1443     if (fontEngine) {
1444         fontEngine->ref.deref();
1445         if (fontEngine->cache_count == 0 && fontEngine->ref == 0)
1446             delete fontEngine;
1447     }
1448 }
1449
1450 void QTextEngine::invalidate()
1451 {
1452     freeMemory();
1453     minWidth = 0;
1454     maxWidth = 0;
1455     if (specialData)
1456         specialData->resolvedFormatIndices.clear();
1457
1458     releaseCachedFontEngine(feCache.prevFontEngine);
1459     releaseCachedFontEngine(feCache.prevScaledFontEngine);
1460     feCache.reset();
1461 }
1462
1463 void QTextEngine::clearLineData()
1464 {
1465     lines.clear();
1466 }
1467
1468 void QTextEngine::validate() const
1469 {
1470     if (layoutData)
1471         return;
1472     layoutData = new LayoutData();
1473     if (block.docHandle()) {
1474         layoutData->string = block.text();
1475         if (option.flags() & QTextOption::ShowLineAndParagraphSeparators)
1476             layoutData->string += QLatin1Char(block.next().isValid() ? 0xb6 : 0x20);
1477     } else {
1478         layoutData->string = text;
1479     }
1480     if (specialData && specialData->preeditPosition != -1)
1481         layoutData->string.insert(specialData->preeditPosition, specialData->preeditText);
1482 }
1483
1484 void QTextEngine::itemize() const
1485 {
1486     validate();
1487     if (layoutData->items.size())
1488         return;
1489
1490     int length = layoutData->string.length();
1491     if (!length)
1492         return;
1493 #if defined(Q_WS_MAC) && !defined(QT_MAC_USE_COCOA)
1494     // ATSUI requires RTL flags to correctly identify the character stops.
1495     bool ignore = false;
1496 #else
1497     bool ignore = ignoreBidi;
1498 #endif
1499
1500     bool rtl = isRightToLeft();
1501
1502     if (!ignore && !rtl) {
1503         ignore = true;
1504         const QChar *start = layoutData->string.unicode();
1505         const QChar * const end = start + length;
1506         while (start < end) {
1507             if (start->unicode() >= 0x590) {
1508                 ignore = false;
1509                 break;
1510             }
1511             ++start;
1512         }
1513     }
1514
1515     QVarLengthArray<QScriptAnalysis, 4096> scriptAnalysis(length);
1516     QScriptAnalysis *analysis = scriptAnalysis.data();
1517
1518     QBidiControl control(rtl);
1519
1520     if (ignore) {
1521         memset(analysis, 0, length*sizeof(QScriptAnalysis));
1522         if (option.textDirection() == Qt::RightToLeft) {
1523             for (int i = 0; i < length; ++i)
1524                 analysis[i].bidiLevel = 1;
1525             layoutData->hasBidi = true;
1526         }
1527     } else {
1528         layoutData->hasBidi = bidiItemize(const_cast<QTextEngine *>(this), analysis, control);
1529     }
1530
1531     const ushort *uc = reinterpret_cast<const ushort *>(layoutData->string.unicode());
1532     const ushort *e = uc + length;
1533     int lastScript = QUnicodeTables::Common;
1534     while (uc < e) {
1535         int script = QUnicodeTables::script(*uc);
1536         if (script == QUnicodeTables::Inherited)
1537             script = lastScript;
1538         analysis->flags = QScriptAnalysis::None;
1539         if (*uc == QChar::ObjectReplacementCharacter) {
1540             if (analysis->bidiLevel % 2)
1541                 --analysis->bidiLevel;
1542             analysis->script = QUnicodeTables::Common;
1543             analysis->flags = QScriptAnalysis::Object;
1544         } else if (*uc == QChar::LineSeparator) {
1545             if (analysis->bidiLevel % 2)
1546                 --analysis->bidiLevel;
1547             analysis->script = QUnicodeTables::Common;
1548             analysis->flags = QScriptAnalysis::LineOrParagraphSeparator;
1549             if (option.flags() & QTextOption::ShowLineAndParagraphSeparators)
1550                 *const_cast<ushort*>(uc) = 0x21B5; // visual line separator
1551         } else if (*uc == 9) {
1552             analysis->script = QUnicodeTables::Common;
1553             analysis->flags = QScriptAnalysis::Tab;
1554             analysis->bidiLevel = control.baseLevel();
1555         } else if ((*uc == 32 || *uc == QChar::Nbsp)
1556                    && (option.flags() & QTextOption::ShowTabsAndSpaces)) {
1557             analysis->script = QUnicodeTables::Common;
1558             analysis->flags = QScriptAnalysis::Space;
1559             analysis->bidiLevel = control.baseLevel();
1560         } else {
1561             analysis->script = script;
1562         }
1563         lastScript = analysis->script;
1564         ++uc;
1565         ++analysis;
1566     }
1567     if (option.flags() & QTextOption::ShowLineAndParagraphSeparators) {
1568         (analysis-1)->flags = QScriptAnalysis::LineOrParagraphSeparator; // to exclude it from width
1569     }
1570
1571     Itemizer itemizer(layoutData->string, scriptAnalysis.data(), layoutData->items);
1572
1573     const QTextDocumentPrivate *p = block.docHandle();
1574     if (p) {
1575         SpecialData *s = specialData;
1576
1577         QTextDocumentPrivate::FragmentIterator it = p->find(block.position());
1578         QTextDocumentPrivate::FragmentIterator end = p->find(block.position() + block.length() - 1); // -1 to omit the block separator char
1579         int format = it.value()->format;
1580
1581         int prevPosition = 0;
1582         int position = prevPosition;
1583         while (1) {
1584             const QTextFragmentData * const frag = it.value();
1585             if (it == end || format != frag->format) {
1586                 if (s && position >= s->preeditPosition) {
1587                     position += s->preeditText.length();
1588                     s = 0;
1589                 }
1590                 Q_ASSERT(position <= length);
1591                 itemizer.generate(prevPosition, position - prevPosition,
1592                     formats()->charFormat(format).fontCapitalization());
1593                 if (it == end) {
1594                     if (position < length)
1595                         itemizer.generate(position, length - position,
1596                                           formats()->charFormat(format).fontCapitalization());
1597                     break;
1598                 }
1599                 format = frag->format;
1600                 prevPosition = position;
1601             }
1602             position += frag->size_array[0];
1603             ++it;
1604         }
1605     } else {
1606         itemizer.generate(0, length, static_cast<QFont::Capitalization> (fnt.d->capital));
1607     }
1608
1609     addRequiredBoundaries();
1610     resolveAdditionalFormats();
1611 }
1612
1613 bool QTextEngine::isRightToLeft() const
1614 {
1615     switch (option.textDirection()) {
1616     case Qt::LeftToRight:
1617         return false;
1618     case Qt::RightToLeft:
1619         return true;
1620     default:
1621         break;
1622     }
1623     if (!layoutData)
1624         itemize();
1625     // this places the cursor in the right position depending on the keyboard layout
1626     if (layoutData->string.isEmpty())
1627         return QApplication::keyboardInputDirection() == Qt::RightToLeft;
1628     return layoutData->string.isRightToLeft();
1629 }
1630
1631
1632 int QTextEngine::findItem(int strPos) const
1633 {
1634     itemize();
1635     int left = 0;
1636     int right = layoutData->items.size()-1;
1637     while(left <= right) {
1638         int middle = ((right-left)/2)+left;
1639         if (strPos > layoutData->items[middle].position)
1640             left = middle+1;
1641         else if(strPos < layoutData->items[middle].position)
1642             right = middle-1;
1643         else {
1644             return middle;
1645         }
1646     }
1647     return right;
1648 }
1649
1650 QFixed QTextEngine::width(int from, int len) const
1651 {
1652     itemize();
1653
1654     QFixed w = 0;
1655
1656 //     qDebug("QTextEngine::width(from = %d, len = %d), numItems=%d, strleng=%d", from,  len, items.size(), string.length());
1657     for (int i = 0; i < layoutData->items.size(); i++) {
1658         const QScriptItem *si = layoutData->items.constData() + i;
1659         int pos = si->position;
1660         int ilen = length(i);
1661 //          qDebug("item %d: from %d len %d", i, pos, ilen);
1662         if (pos >= from + len)
1663             break;
1664         if (pos + ilen > from) {
1665             if (!si->num_glyphs)
1666                 shape(i);
1667
1668             if (si->analysis.flags == QScriptAnalysis::Object) {
1669                 w += si->width;
1670                 continue;
1671             } else if (si->analysis.flags == QScriptAnalysis::Tab) {
1672                 w += calculateTabWidth(i, w);
1673                 continue;
1674             }
1675
1676
1677             QGlyphLayout glyphs = shapedGlyphs(si);
1678             unsigned short *logClusters = this->logClusters(si);
1679
1680 //             fprintf(stderr, "  logclusters:");
1681 //             for (int k = 0; k < ilen; k++)
1682 //                 fprintf(stderr, " %d", logClusters[k]);
1683 //             fprintf(stderr, "\n");
1684             // do the simple thing for now and give the first glyph in a cluster the full width, all other ones 0.
1685             int charFrom = from - pos;
1686             if (charFrom < 0)
1687                 charFrom = 0;
1688             int glyphStart = logClusters[charFrom];
1689             if (charFrom > 0 && logClusters[charFrom-1] == glyphStart)
1690                 while (charFrom < ilen && logClusters[charFrom] == glyphStart)
1691                     charFrom++;
1692             if (charFrom < ilen) {
1693                 glyphStart = logClusters[charFrom];
1694                 int charEnd = from + len - 1 - pos;
1695                 if (charEnd >= ilen)
1696                     charEnd = ilen-1;
1697                 int glyphEnd = logClusters[charEnd];
1698                 while (charEnd < ilen && logClusters[charEnd] == glyphEnd)
1699                     charEnd++;
1700                 glyphEnd = (charEnd == ilen) ? si->num_glyphs : logClusters[charEnd];
1701
1702 //                 qDebug("char: start=%d end=%d / glyph: start = %d, end = %d", charFrom, charEnd, glyphStart, glyphEnd);
1703                 for (int i = glyphStart; i < glyphEnd; i++)
1704                     w += glyphs.advances_x[i] * !glyphs.attributes[i].dontPrint;
1705             }
1706         }
1707     }
1708 //     qDebug("   --> w= %d ", w);
1709     return w;
1710 }
1711
1712 glyph_metrics_t QTextEngine::boundingBox(int from,  int len) const
1713 {
1714     itemize();
1715
1716     glyph_metrics_t gm;
1717
1718     for (int i = 0; i < layoutData->items.size(); i++) {
1719         const QScriptItem *si = layoutData->items.constData() + i;
1720
1721         int pos = si->position;
1722         int ilen = length(i);
1723         if (pos > from + len)
1724             break;
1725         if (pos + ilen > from) {
1726             if (!si->num_glyphs)
1727                 shape(i);
1728
1729             if (si->analysis.flags == QScriptAnalysis::Object) {
1730                 gm.width += si->width;
1731                 continue;
1732             } else if (si->analysis.flags == QScriptAnalysis::Tab) {
1733                 gm.width += calculateTabWidth(i, gm.width);
1734                 continue;
1735             }
1736
1737             unsigned short *logClusters = this->logClusters(si);
1738             QGlyphLayout glyphs = shapedGlyphs(si);
1739
1740             // do the simple thing for now and give the first glyph in a cluster the full width, all other ones 0.
1741             int charFrom = from - pos;
1742             if (charFrom < 0)
1743                 charFrom = 0;
1744             int glyphStart = logClusters[charFrom];
1745             if (charFrom > 0 && logClusters[charFrom-1] == glyphStart)
1746                 while (charFrom < ilen && logClusters[charFrom] == glyphStart)
1747                     charFrom++;
1748             if (charFrom < ilen) {
1749                 QFontEngine *fe = fontEngine(*si);
1750                 glyphStart = logClusters[charFrom];
1751                 int charEnd = from + len - 1 - pos;
1752                 if (charEnd >= ilen)
1753                     charEnd = ilen-1;
1754                 int glyphEnd = logClusters[charEnd];
1755                 while (charEnd < ilen && logClusters[charEnd] == glyphEnd)
1756                     charEnd++;
1757                 glyphEnd = (charEnd == ilen) ? si->num_glyphs : logClusters[charEnd];
1758                 if (glyphStart <= glyphEnd ) {
1759                     glyph_metrics_t m = fe->boundingBox(glyphs.mid(glyphStart, glyphEnd - glyphStart));
1760                     gm.x = qMin(gm.x, m.x + gm.xoff);
1761                     gm.y = qMin(gm.y, m.y + gm.yoff);
1762                     gm.width = qMax(gm.width, m.width+gm.xoff);
1763                     gm.height = qMax(gm.height, m.height+gm.yoff);
1764                     gm.xoff += m.xoff;
1765                     gm.yoff += m.yoff;
1766                 }
1767             }
1768         }
1769     }
1770     return gm;
1771 }
1772
1773 glyph_metrics_t QTextEngine::tightBoundingBox(int from,  int len) const
1774 {
1775     itemize();
1776
1777     glyph_metrics_t gm;
1778
1779     for (int i = 0; i < layoutData->items.size(); i++) {
1780         const QScriptItem *si = layoutData->items.constData() + i;
1781         int pos = si->position;
1782         int ilen = length(i);
1783         if (pos > from + len)
1784             break;
1785         if (pos + len > from) {
1786             if (!si->num_glyphs)
1787                 shape(i);
1788             unsigned short *logClusters = this->logClusters(si);
1789             QGlyphLayout glyphs = shapedGlyphs(si);
1790
1791             // do the simple thing for now and give the first glyph in a cluster the full width, all other ones 0.
1792             int charFrom = from - pos;
1793             if (charFrom < 0)
1794                 charFrom = 0;
1795             int glyphStart = logClusters[charFrom];
1796             if (charFrom > 0 && logClusters[charFrom-1] == glyphStart)
1797                 while (charFrom < ilen && logClusters[charFrom] == glyphStart)
1798                     charFrom++;
1799             if (charFrom < ilen) {
1800                 glyphStart = logClusters[charFrom];
1801                 int charEnd = from + len - 1 - pos;
1802                 if (charEnd >= ilen)
1803                     charEnd = ilen-1;
1804                 int glyphEnd = logClusters[charEnd];
1805                 while (charEnd < ilen && logClusters[charEnd] == glyphEnd)
1806                     charEnd++;
1807                 glyphEnd = (charEnd == ilen) ? si->num_glyphs : logClusters[charEnd];
1808                 if (glyphStart <= glyphEnd ) {
1809                     QFontEngine *fe = fontEngine(*si);
1810                     glyph_metrics_t m = fe->tightBoundingBox(glyphs.mid(glyphStart, glyphEnd - glyphStart));
1811                     gm.x = qMin(gm.x, m.x + gm.xoff);
1812                     gm.y = qMin(gm.y, m.y + gm.yoff);
1813                     gm.width = qMax(gm.width, m.width+gm.xoff);
1814                     gm.height = qMax(gm.height, m.height+gm.yoff);
1815                     gm.xoff += m.xoff;
1816                     gm.yoff += m.yoff;
1817                 }
1818             }
1819         }
1820     }
1821     return gm;
1822 }
1823
1824 QFont QTextEngine::font(const QScriptItem &si) const
1825 {
1826     QFont font = fnt;
1827     if (hasFormats()) {
1828         QTextCharFormat f = format(&si);
1829         font = f.font();
1830
1831         if (block.docHandle() && block.docHandle()->layout()) {
1832             // Make sure we get the right dpi on printers
1833             QPaintDevice *pdev = block.docHandle()->layout()->paintDevice();
1834             if (pdev)
1835                 font = QFont(font, pdev);
1836         } else {
1837             font = font.resolve(fnt);
1838         }
1839         QTextCharFormat::VerticalAlignment valign = f.verticalAlignment();
1840         if (valign == QTextCharFormat::AlignSuperScript || valign == QTextCharFormat::AlignSubScript) {
1841             if (font.pointSize() != -1)
1842                 font.setPointSize((font.pointSize() * 2) / 3);
1843             else
1844                 font.setPixelSize((font.pixelSize() * 2) / 3);
1845         }
1846     }
1847
1848     if (si.analysis.flags == QScriptAnalysis::SmallCaps)
1849         font = font.d->smallCapsFont();
1850
1851     return font;
1852 }
1853
1854 QTextEngine::FontEngineCache::FontEngineCache()
1855 {
1856     reset();
1857 }
1858
1859 //we cache the previous results of this function, as calling it numerous times with the same effective
1860 //input is common (and hard to cache at a higher level)
1861 QFontEngine *QTextEngine::fontEngine(const QScriptItem &si, QFixed *ascent, QFixed *descent, QFixed *leading) const
1862 {
1863     QFontEngine *engine = 0;
1864     QFontEngine *scaledEngine = 0;
1865     int script = si.analysis.script;
1866
1867     QFont font = fnt;
1868     if (hasFormats()) {
1869         if (feCache.prevFontEngine && feCache.prevPosition == si.position && feCache.prevLength == length(&si) && feCache.prevScript == script) {
1870             engine = feCache.prevFontEngine;
1871             scaledEngine = feCache.prevScaledFontEngine;
1872         } else {
1873             QTextCharFormat f = format(&si);
1874             font = f.font();
1875
1876             if (block.docHandle() && block.docHandle()->layout()) {
1877                 // Make sure we get the right dpi on printers
1878                 QPaintDevice *pdev = block.docHandle()->layout()->paintDevice();
1879                 if (pdev)
1880                     font = QFont(font, pdev);
1881             } else {
1882                 font = font.resolve(fnt);
1883             }
1884             engine = font.d->engineForScript(script);
1885             QTextCharFormat::VerticalAlignment valign = f.verticalAlignment();
1886             if (valign == QTextCharFormat::AlignSuperScript || valign == QTextCharFormat::AlignSubScript) {
1887                 if (font.pointSize() != -1)
1888                     font.setPointSize((font.pointSize() * 2) / 3);
1889                 else
1890                     font.setPixelSize((font.pixelSize() * 2) / 3);
1891                 scaledEngine = font.d->engineForScript(script);
1892             }
1893             feCache.prevFontEngine = engine;
1894             if (engine)
1895                 engine->ref.ref();
1896             feCache.prevScaledFontEngine = scaledEngine;
1897             if (scaledEngine)
1898                 scaledEngine->ref.ref();
1899             feCache.prevScript = script;
1900             feCache.prevPosition = si.position;
1901             feCache.prevLength = length(&si);
1902         }
1903     } else {
1904         if (feCache.prevFontEngine && feCache.prevScript == script && feCache.prevPosition == -1)
1905             engine = feCache.prevFontEngine;
1906         else {
1907             engine = font.d->engineForScript(script);
1908             feCache.prevFontEngine = engine;
1909             if (engine)
1910                 engine->ref.ref();
1911             feCache.prevScript = script;
1912             feCache.prevPosition = -1;
1913             feCache.prevLength = -1;
1914             feCache.prevScaledFontEngine = 0;
1915         }
1916     }
1917
1918     if (si.analysis.flags == QScriptAnalysis::SmallCaps) {
1919         QFontPrivate *p = font.d->smallCapsFontPrivate();
1920         scaledEngine = p->engineForScript(script);
1921     }
1922
1923     if (ascent) {
1924         *ascent = engine->ascent();
1925         *descent = engine->descent();
1926         *leading = engine->leading();
1927     }
1928
1929     if (scaledEngine)
1930         return scaledEngine;
1931     return engine;
1932 }
1933
1934 struct QJustificationPoint {
1935     int type;
1936     QFixed kashidaWidth;
1937     QGlyphLayout glyph;
1938     QFontEngine *fontEngine;
1939 };
1940
1941 Q_DECLARE_TYPEINFO(QJustificationPoint, Q_PRIMITIVE_TYPE);
1942
1943 static void set(QJustificationPoint *point, int type, const QGlyphLayout &glyph, QFontEngine *fe)
1944 {
1945     point->type = type;
1946     point->glyph = glyph;
1947     point->fontEngine = fe;
1948
1949     if (type >= HB_Arabic_Normal) {
1950         QChar ch(0x640); // Kashida character
1951         QGlyphLayoutArray<8> glyphs;
1952         int nglyphs = 7;
1953         fe->stringToCMap(&ch, 1, &glyphs, &nglyphs, 0);
1954         if (glyphs.glyphs[0] && glyphs.advances_x[0] != 0) {
1955             point->kashidaWidth = glyphs.advances_x[0];
1956         } else {
1957             point->type = HB_NoJustification;
1958             point->kashidaWidth = 0;
1959         }
1960     }
1961 }
1962
1963
1964 void QTextEngine::justify(const QScriptLine &line)
1965 {
1966 //     qDebug("justify: line.gridfitted = %d, line.justified=%d", line.gridfitted, line.justified);
1967     if (line.gridfitted && line.justified)
1968         return;
1969
1970     if (!line.gridfitted) {
1971         // redo layout in device metrics, then adjust
1972         const_cast<QScriptLine &>(line).gridfitted = true;
1973     }
1974
1975     if ((option.alignment() & Qt::AlignHorizontal_Mask) != Qt::AlignJustify)
1976         return;
1977
1978     itemize();
1979
1980     if (!forceJustification) {
1981         int end = line.from + (int)line.length;
1982         if (end == layoutData->string.length())
1983             return; // no justification at end of paragraph
1984         if (end && layoutData->items[findItem(end-1)].analysis.flags == QScriptAnalysis::LineOrParagraphSeparator)
1985             return; // no justification at the end of an explicitly separated line
1986     }
1987
1988     // justify line
1989     int maxJustify = 0;
1990
1991     // don't include trailing white spaces when doing justification
1992     int line_length = line.length;
1993     const HB_CharAttributes *a = attributes();
1994     if (! a)
1995         return;
1996     a += line.from;
1997     while (line_length && a[line_length-1].whiteSpace)
1998         --line_length;
1999     // subtract one char more, as we can't justfy after the last character
2000     --line_length;
2001
2002     if (!line_length)
2003         return;
2004
2005     int firstItem = findItem(line.from);
2006     int nItems = findItem(line.from + line_length - 1) - firstItem + 1;
2007
2008     QVarLengthArray<QJustificationPoint> justificationPoints;
2009     int nPoints = 0;
2010 //     qDebug("justifying from %d len %d, firstItem=%d, nItems=%d (%s)", line.from, line_length, firstItem, nItems, layoutData->string.mid(line.from, line_length).toUtf8().constData());
2011     QFixed minKashida = 0x100000;
2012
2013     // we need to do all shaping before we go into the next loop, as we there
2014     // store pointers to the glyph data that could get reallocated by the shaping
2015     // process.
2016     for (int i = 0; i < nItems; ++i) {
2017         QScriptItem &si = layoutData->items[firstItem + i];
2018         if (!si.num_glyphs)
2019             shape(firstItem + i);
2020     }
2021
2022     for (int i = 0; i < nItems; ++i) {
2023         QScriptItem &si = layoutData->items[firstItem + i];
2024
2025         int kashida_type = HB_Arabic_Normal;
2026         int kashida_pos = -1;
2027
2028         int start = qMax(line.from - si.position, 0);
2029         int end = qMin(line.from + line_length - (int)si.position, length(firstItem+i));
2030
2031         unsigned short *log_clusters = logClusters(&si);
2032
2033         int gs = log_clusters[start];
2034         int ge = (end == length(firstItem+i) ? si.num_glyphs : log_clusters[end]);
2035
2036         const QGlyphLayout g = shapedGlyphs(&si);
2037
2038         for (int i = gs; i < ge; ++i) {
2039             g.justifications[i].type = QGlyphJustification::JustifyNone;
2040             g.justifications[i].nKashidas = 0;
2041             g.justifications[i].space_18d6 = 0;
2042
2043             justificationPoints.resize(nPoints+3);
2044             int justification = g.attributes[i].justification;
2045
2046             switch(justification) {
2047             case HB_NoJustification:
2048                 break;
2049             case HB_Space          :
2050                 // fall through
2051             case HB_Arabic_Space   :
2052                 if (kashida_pos >= 0) {
2053 //                     qDebug("kashida position at %d in word", kashida_pos);
2054                     set(&justificationPoints[nPoints], kashida_type, g.mid(kashida_pos), fontEngine(si));
2055                     if (justificationPoints[nPoints].kashidaWidth > 0) {
2056                         minKashida = qMin(minKashida, justificationPoints[nPoints].kashidaWidth);
2057                         maxJustify = qMax(maxJustify, justificationPoints[nPoints].type);
2058                         ++nPoints;
2059                     }
2060                 }
2061                 kashida_pos = -1;
2062                 kashida_type = HB_Arabic_Normal;
2063                 // fall through
2064             case HB_Character      :
2065                 set(&justificationPoints[nPoints++], justification, g.mid(i), fontEngine(si));
2066                 maxJustify = qMax(maxJustify, justification);
2067                 break;
2068             case HB_Arabic_Normal  :
2069             case HB_Arabic_Waw     :
2070             case HB_Arabic_BaRa    :
2071             case HB_Arabic_Alef    :
2072             case HB_Arabic_HaaDal  :
2073             case HB_Arabic_Seen    :
2074             case HB_Arabic_Kashida :
2075                 if (justification >= kashida_type) {
2076                     kashida_pos = i;
2077                     kashida_type = justification;
2078                 }
2079             }
2080         }
2081         if (kashida_pos >= 0) {
2082             set(&justificationPoints[nPoints], kashida_type, g.mid(kashida_pos), fontEngine(si));
2083             if (justificationPoints[nPoints].kashidaWidth > 0) {
2084                 minKashida = qMin(minKashida, justificationPoints[nPoints].kashidaWidth);
2085                 maxJustify = qMax(maxJustify, justificationPoints[nPoints].type);
2086                 ++nPoints;
2087             }
2088         }
2089     }
2090
2091     QFixed need = line.width - line.textWidth;
2092     if (need < 0) {
2093         // line overflows already!
2094         const_cast<QScriptLine &>(line).justified = true;
2095         return;
2096     }
2097
2098 //     qDebug("doing justification: textWidth=%x, requested=%x, maxJustify=%d", line.textWidth.value(), line.width.value(), maxJustify);
2099 //     qDebug("     minKashida=%f, need=%f", minKashida.toReal(), need.toReal());
2100
2101     // distribute in priority order
2102     if (maxJustify >= HB_Arabic_Normal) {
2103         while (need >= minKashida) {
2104             for (int type = maxJustify; need >= minKashida && type >= HB_Arabic_Normal; --type) {
2105                 for (int i = 0; need >= minKashida && i < nPoints; ++i) {
2106                     if (justificationPoints[i].type == type && justificationPoints[i].kashidaWidth <= need) {
2107                         justificationPoints[i].glyph.justifications->nKashidas++;
2108                         // ############
2109                         justificationPoints[i].glyph.justifications->space_18d6 += justificationPoints[i].kashidaWidth.value();
2110                         need -= justificationPoints[i].kashidaWidth;
2111 //                         qDebug("adding kashida type %d with width %x, neednow %x", type, justificationPoints[i].kashidaWidth, need.value());
2112                     }
2113                 }
2114             }
2115         }
2116     }
2117     Q_ASSERT(need >= 0);
2118     if (!need)
2119         goto end;
2120
2121     maxJustify = qMin(maxJustify, (int)HB_Space);
2122     for (int type = maxJustify; need != 0 && type > 0; --type) {
2123         int n = 0;
2124         for (int i = 0; i < nPoints; ++i) {
2125             if (justificationPoints[i].type == type)
2126                 ++n;
2127         }
2128 //          qDebug("number of points for justification type %d: %d", type, n);
2129
2130
2131         if (!n)
2132             continue;
2133
2134         for (int i = 0; i < nPoints; ++i) {
2135             if (justificationPoints[i].type == type) {
2136                 QFixed add = need/n;
2137 //                  qDebug("adding %x to glyph %x", add.value(), justificationPoints[i].glyph->glyph);
2138                 justificationPoints[i].glyph.justifications[0].space_18d6 = add.value();
2139                 need -= add;
2140                 --n;
2141             }
2142         }
2143
2144         Q_ASSERT(!need);
2145     }
2146  end:
2147     const_cast<QScriptLine &>(line).justified = true;
2148 }
2149
2150 void QScriptLine::setDefaultHeight(QTextEngine *eng)
2151 {
2152     QFont f;
2153     QFontEngine *e;
2154
2155     if (eng->block.docHandle() && eng->block.docHandle()->layout()) {
2156         f = eng->block.charFormat().font();
2157         // Make sure we get the right dpi on printers
2158         QPaintDevice *pdev = eng->block.docHandle()->layout()->paintDevice();
2159         if (pdev)
2160             f = QFont(f, pdev);
2161         e = f.d->engineForScript(QUnicodeTables::Common);
2162     } else {
2163         e = eng->fnt.d->engineForScript(QUnicodeTables::Common);
2164     }
2165
2166     QFixed other_ascent = e->ascent();
2167     QFixed other_descent = e->descent();
2168     QFixed other_leading = e->leading();
2169     leading = qMax(leading + ascent, other_leading + other_ascent) - qMax(ascent, other_ascent);
2170     ascent = qMax(ascent, other_ascent);
2171     descent = qMax(descent, other_descent);
2172 }
2173
2174 QTextEngine::LayoutData::LayoutData()
2175 {
2176     memory = 0;
2177     allocated = 0;
2178     memory_on_stack = false;
2179     used = 0;
2180     hasBidi = false;
2181     layoutState = LayoutEmpty;
2182     haveCharAttributes = false;
2183     logClustersPtr = 0;
2184     available_glyphs = 0;
2185 }
2186
2187 QTextEngine::LayoutData::LayoutData(const QString &str, void **stack_memory, int _allocated)
2188     : string(str)
2189 {
2190     allocated = _allocated;
2191
2192     int space_charAttributes = sizeof(HB_CharAttributes)*string.length()/sizeof(void*) + 1;
2193     int space_logClusters = sizeof(unsigned short)*string.length()/sizeof(void*) + 1;
2194     available_glyphs = ((int)allocated - space_charAttributes - space_logClusters)*(int)sizeof(void*)/(int)QGlyphLayout::spaceNeededForGlyphLayout(1);
2195
2196     if (available_glyphs < str.length()) {
2197         // need to allocate on the heap
2198         allocated = 0;
2199
2200         memory_on_stack = false;
2201         memory = 0;
2202         logClustersPtr = 0;
2203     } else {
2204         memory_on_stack = true;
2205         memory = stack_memory;
2206         logClustersPtr = (unsigned short *)(memory + space_charAttributes);
2207
2208         void *m = memory + space_charAttributes + space_logClusters;
2209         glyphLayout = QGlyphLayout(reinterpret_cast<char *>(m), str.length());
2210         glyphLayout.clear();
2211         memset(memory, 0, space_charAttributes*sizeof(void *));
2212     }
2213     used = 0;
2214     hasBidi = false;
2215     layoutState = LayoutEmpty;
2216     haveCharAttributes = false;
2217 }
2218
2219 QTextEngine::LayoutData::~LayoutData()
2220 {
2221     if (!memory_on_stack)
2222         free(memory);
2223     memory = 0;
2224 }
2225
2226 bool QTextEngine::LayoutData::reallocate(int totalGlyphs)
2227 {
2228     Q_ASSERT(totalGlyphs >= glyphLayout.numGlyphs);
2229     if (memory_on_stack && available_glyphs >= totalGlyphs) {
2230         glyphLayout.grow(glyphLayout.data(), totalGlyphs);
2231         return true;
2232     }
2233
2234     int space_charAttributes = sizeof(HB_CharAttributes)*string.length()/sizeof(void*) + 1;
2235     int space_logClusters = sizeof(unsigned short)*string.length()/sizeof(void*) + 1;
2236     int space_glyphs = QGlyphLayout::spaceNeededForGlyphLayout(totalGlyphs)/sizeof(void*) + 2;
2237
2238     int newAllocated = space_charAttributes + space_glyphs + space_logClusters;
2239     // These values can be negative if the length of string/glyphs causes overflow,
2240     // we can't layout such a long string all at once, so return false here to
2241     // indicate there is a failure
2242     if (space_charAttributes < 0 || space_logClusters < 0 || space_glyphs < 0 || newAllocated < allocated) {
2243         layoutState = LayoutFailed;
2244         return false;
2245     }
2246
2247     void **newMem = memory;
2248     newMem = (void **)::realloc(memory_on_stack ? 0 : memory, newAllocated*sizeof(void *));
2249     if (!newMem) {
2250         layoutState = LayoutFailed;
2251         return false;
2252     }
2253     if (memory_on_stack)
2254         memcpy(newMem, memory, allocated*sizeof(void *));
2255     memory = newMem;
2256     memory_on_stack = false;
2257
2258     void **m = memory;
2259     m += space_charAttributes;
2260     logClustersPtr = (unsigned short *) m;
2261     m += space_logClusters;
2262
2263     const int space_preGlyphLayout = space_charAttributes + space_logClusters;
2264     if (allocated < space_preGlyphLayout)
2265         memset(memory + allocated, 0, (space_preGlyphLayout - allocated)*sizeof(void *));
2266
2267     glyphLayout.grow(reinterpret_cast<char *>(m), totalGlyphs);
2268
2269     allocated = newAllocated;
2270     return true;
2271 }
2272
2273 // grow to the new size, copying the existing data to the new layout
2274 void QGlyphLayout::grow(char *address, int totalGlyphs)
2275 {
2276     QGlyphLayout oldLayout(address, numGlyphs);
2277     QGlyphLayout newLayout(address, totalGlyphs);
2278
2279     if (numGlyphs) {
2280         // move the existing data
2281         memmove(newLayout.attributes, oldLayout.attributes, numGlyphs * sizeof(HB_GlyphAttributes));
2282         memmove(newLayout.justifications, oldLayout.justifications, numGlyphs * sizeof(QGlyphJustification));
2283         memmove(newLayout.advances_y, oldLayout.advances_y, numGlyphs * sizeof(QFixed));
2284         memmove(newLayout.advances_x, oldLayout.advances_x, numGlyphs * sizeof(QFixed));
2285         memmove(newLayout.glyphs, oldLayout.glyphs, numGlyphs * sizeof(HB_Glyph));
2286     }
2287
2288     // clear the new data
2289     newLayout.clear(numGlyphs);
2290
2291     *this = newLayout;
2292 }
2293
2294 void QTextEngine::freeMemory()
2295 {
2296     if (!stackEngine) {
2297         delete layoutData;
2298         layoutData = 0;
2299     } else {
2300         layoutData->used = 0;
2301         layoutData->hasBidi = false;
2302         layoutData->layoutState = LayoutEmpty;
2303         layoutData->haveCharAttributes = false;
2304     }
2305     for (int i = 0; i < lines.size(); ++i) {
2306         lines[i].justified = 0;
2307         lines[i].gridfitted = 0;
2308     }
2309 }
2310
2311 int QTextEngine::formatIndex(const QScriptItem *si) const
2312 {
2313     if (specialData && !specialData->resolvedFormatIndices.isEmpty())
2314         return specialData->resolvedFormatIndices.at(si - &layoutData->items[0]);
2315     QTextDocumentPrivate *p = block.docHandle();
2316     if (!p)
2317         return -1;
2318     int pos = si->position;
2319     if (specialData && si->position >= specialData->preeditPosition) {
2320         if (si->position < specialData->preeditPosition + specialData->preeditText.length())
2321             pos = qMax(specialData->preeditPosition - 1, 0);
2322         else
2323             pos -= specialData->preeditText.length();
2324     }
2325     QTextDocumentPrivate::FragmentIterator it = p->find(block.position() + pos);
2326     return it.value()->format;
2327 }
2328
2329
2330 QTextCharFormat QTextEngine::format(const QScriptItem *si) const
2331 {
2332     QTextCharFormat format;
2333     const QTextFormatCollection *formats = 0;
2334     if (block.docHandle()) {
2335         formats = this->formats();
2336         format = formats->charFormat(formatIndex(si));
2337     }
2338     if (specialData && specialData->resolvedFormatIndices.isEmpty()) {
2339         int end = si->position + length(si);
2340         for (int i = 0; i < specialData->addFormats.size(); ++i) {
2341             const QTextLayout::FormatRange &r = specialData->addFormats.at(i);
2342             if (r.start <= si->position && r.start + r.length >= end) {
2343                 if (!specialData->addFormatIndices.isEmpty())
2344                     format.merge(formats->format(specialData->addFormatIndices.at(i)));
2345                 else
2346                     format.merge(r.format);
2347             }
2348         }
2349     }
2350     return format;
2351 }
2352
2353 void QTextEngine::addRequiredBoundaries() const
2354 {
2355     if (specialData) {
2356         for (int i = 0; i < specialData->addFormats.size(); ++i) {
2357             const QTextLayout::FormatRange &r = specialData->addFormats.at(i);
2358             setBoundary(r.start);
2359             setBoundary(r.start + r.length);
2360             //qDebug("adding boundaries %d %d", r.start, r.start+r.length);
2361         }
2362     }
2363 }
2364
2365 bool QTextEngine::atWordSeparator(int position) const
2366 {
2367     const QChar c = layoutData->string.at(position);
2368     switch (c.toLatin1()) {
2369     case '.':
2370     case ',':
2371     case '?':
2372     case '!':
2373     case '@':
2374     case '#':
2375     case '$':
2376     case ':':
2377     case ';':
2378     case '-':
2379     case '<':
2380     case '>':
2381     case '[':
2382     case ']':
2383     case '(':
2384     case ')':
2385     case '{':
2386     case '}':
2387     case '=':
2388     case '/':
2389     case '+':
2390     case '%':
2391     case '&':
2392     case '^':
2393     case '*':
2394     case '\'':
2395     case '"':
2396     case '`':
2397     case '~':
2398     case '|':
2399         return true;
2400     default:
2401         return false;
2402     }
2403 }
2404
2405 bool QTextEngine::atSpace(int position) const
2406 {
2407     const QChar c = layoutData->string.at(position);
2408
2409     return c == QLatin1Char(' ')
2410         || c == QChar::Nbsp
2411         || c == QChar::LineSeparator
2412         || c == QLatin1Char('\t')
2413         ;
2414 }
2415
2416
2417 void QTextEngine::indexAdditionalFormats()
2418 {
2419     if (!block.docHandle())
2420         return;
2421
2422     specialData->addFormatIndices.resize(specialData->addFormats.count());
2423     QTextFormatCollection * const formats = this->formats();
2424
2425     for (int i = 0; i < specialData->addFormats.count(); ++i) {
2426         specialData->addFormatIndices[i] = formats->indexForFormat(specialData->addFormats.at(i).format);
2427         specialData->addFormats[i].format = QTextCharFormat();
2428     }
2429 }
2430
2431 /* These two helper functions are used to determine whether we need to insert a ZWJ character
2432    between the text that gets truncated and the ellipsis. This is important to get
2433    correctly shaped results for arabic text.
2434 */
2435 static bool nextCharJoins(const QString &string, int pos)
2436 {
2437     while (pos < string.length() && string.at(pos).category() == QChar::Mark_NonSpacing)
2438         ++pos;
2439     if (pos == string.length())
2440         return false;
2441     return string.at(pos).joining() != QChar::OtherJoining;
2442 }
2443
2444 static bool prevCharJoins(const QString &string, int pos)
2445 {
2446     while (pos > 0 && string.at(pos - 1).category() == QChar::Mark_NonSpacing)
2447         --pos;
2448     if (pos == 0)
2449         return false;
2450     return (string.at(pos - 1).joining() == QChar::Dual || string.at(pos - 1).joining() == QChar::Center);
2451 }
2452
2453 QString QTextEngine::elidedText(Qt::TextElideMode mode, const QFixed &width, int flags) const
2454 {
2455 //    qDebug() << "elidedText; available width" << width.toReal() << "text width:" << this->width(0, layoutData->string.length()).toReal();
2456
2457     if (flags & Qt::TextShowMnemonic) {
2458         itemize();
2459         HB_CharAttributes *attributes = const_cast<HB_CharAttributes *>(this->attributes());
2460         if (!attributes)
2461             return QString();
2462         for (int i = 0; i < layoutData->items.size(); ++i) {
2463             QScriptItem &si = layoutData->items[i];
2464             if (!si.num_glyphs)
2465                 shape(i);
2466
2467             unsigned short *logClusters = this->logClusters(&si);
2468             QGlyphLayout glyphs = shapedGlyphs(&si);
2469
2470             const int end = si.position + length(&si);
2471             for (int i = si.position; i < end - 1; ++i) {
2472                 if (layoutData->string.at(i) == QLatin1Char('&')) {
2473                     const int gp = logClusters[i - si.position];
2474                     glyphs.attributes[gp].dontPrint = true;
2475                     attributes[i + 1].charStop = false;
2476                     attributes[i + 1].whiteSpace = false;
2477                     attributes[i + 1].lineBreakType = HB_NoBreak;
2478                     if (layoutData->string.at(i + 1) == QLatin1Char('&'))
2479                         ++i;
2480                 }
2481             }
2482         }
2483     }
2484
2485     validate();
2486
2487     if (mode == Qt::ElideNone
2488         || this->width(0, layoutData->string.length()) <= width
2489         || layoutData->string.length() <= 1)
2490         return layoutData->string;
2491
2492     QFixed ellipsisWidth;
2493     QString ellipsisText;
2494     {
2495         QChar ellipsisChar(0x2026);
2496
2497         QFontEngine *fe = fnt.d->engineForScript(QUnicodeTables::Common);
2498
2499         QGlyphLayoutArray<1> ellipsisGlyph;
2500         {
2501             QFontEngine *feForEllipsis = (fe->type() == QFontEngine::Multi)
2502                 ? static_cast<QFontEngineMulti *>(fe)->engine(0)
2503                 : fe;
2504
2505             if (feForEllipsis->type() == QFontEngine::Mac)
2506                 feForEllipsis = fe;
2507
2508             // the lookup can be really slow when we use XLFD fonts
2509             if (feForEllipsis->type() != QFontEngine::XLFD
2510                 && feForEllipsis->canRender(&ellipsisChar, 1)) {
2511                     int nGlyphs = 1;
2512                     feForEllipsis->stringToCMap(&ellipsisChar, 1, &ellipsisGlyph, &nGlyphs, 0);
2513                 }
2514         }
2515
2516         if (ellipsisGlyph.glyphs[0]) {
2517             ellipsisWidth = ellipsisGlyph.advances_x[0];
2518             ellipsisText = ellipsisChar;
2519         } else {
2520             QString dotDotDot(QLatin1String("..."));
2521
2522             QGlyphLayoutArray<3> glyphs;
2523             int nGlyphs = 3;
2524             if (!fe->stringToCMap(dotDotDot.constData(), 3, &glyphs, &nGlyphs, 0))
2525                 // should never happen...
2526                 return layoutData->string;
2527             for (int i = 0; i < nGlyphs; ++i)
2528                 ellipsisWidth += glyphs.advances_x[i];
2529             ellipsisText = dotDotDot;
2530         }
2531     }
2532
2533     const QFixed availableWidth = width - ellipsisWidth;
2534     if (availableWidth < 0)
2535         return QString();
2536
2537     const HB_CharAttributes *attributes = this->attributes();
2538     if (!attributes)
2539         return QString();
2540
2541     if (mode == Qt::ElideRight) {
2542         QFixed currentWidth;
2543         int pos;
2544         int nextBreak = 0;
2545
2546         do {
2547             pos = nextBreak;
2548
2549             ++nextBreak;
2550             while (nextBreak < layoutData->string.length() && !attributes[nextBreak].charStop)
2551                 ++nextBreak;
2552
2553             currentWidth += this->width(pos, nextBreak - pos);
2554         } while (nextBreak < layoutData->string.length()
2555                  && currentWidth < availableWidth);
2556
2557         if (nextCharJoins(layoutData->string, pos))
2558             ellipsisText.prepend(QChar(0x200d) /* ZWJ */);
2559
2560         return layoutData->string.left(pos) + ellipsisText;
2561     } else if (mode == Qt::ElideLeft) {
2562         QFixed currentWidth;
2563         int pos;
2564         int nextBreak = layoutData->string.length();
2565
2566         do {
2567             pos = nextBreak;
2568
2569             --nextBreak;
2570             while (nextBreak > 0 && !attributes[nextBreak].charStop)
2571                 --nextBreak;
2572
2573             currentWidth += this->width(nextBreak, pos - nextBreak);
2574         } while (nextBreak > 0
2575                  && currentWidth < availableWidth);
2576
2577         if (prevCharJoins(layoutData->string, pos))
2578             ellipsisText.append(QChar(0x200d) /* ZWJ */);
2579
2580         return ellipsisText + layoutData->string.mid(pos);
2581     } else if (mode == Qt::ElideMiddle) {
2582         QFixed leftWidth;
2583         QFixed rightWidth;
2584
2585         int leftPos = 0;
2586         int nextLeftBreak = 0;
2587
2588         int rightPos = layoutData->string.length();
2589         int nextRightBreak = layoutData->string.length();
2590
2591         do {
2592             leftPos = nextLeftBreak;
2593             rightPos = nextRightBreak;
2594
2595             ++nextLeftBreak;
2596             while (nextLeftBreak < layoutData->string.length() && !attributes[nextLeftBreak].charStop)
2597                 ++nextLeftBreak;
2598
2599             --nextRightBreak;
2600             while (nextRightBreak > 0 && !attributes[nextRightBreak].charStop)
2601                 --nextRightBreak;
2602
2603             leftWidth += this->width(leftPos, nextLeftBreak - leftPos);
2604             rightWidth += this->width(nextRightBreak, rightPos - nextRightBreak);
2605         } while (nextLeftBreak < layoutData->string.length()
2606                  && nextRightBreak > 0
2607                  && leftWidth + rightWidth < availableWidth);
2608
2609         if (nextCharJoins(layoutData->string, leftPos))
2610             ellipsisText.prepend(QChar(0x200d) /* ZWJ */);
2611         if (prevCharJoins(layoutData->string, rightPos))
2612             ellipsisText.append(QChar(0x200d) /* ZWJ */);
2613
2614         return layoutData->string.left(leftPos) + ellipsisText + layoutData->string.mid(rightPos);
2615     }
2616
2617     return layoutData->string;
2618 }
2619
2620 void QTextEngine::setBoundary(int strPos) const
2621 {
2622     if (strPos <= 0 || strPos >= layoutData->string.length())
2623         return;
2624
2625     int itemToSplit = 0;
2626     while (itemToSplit < layoutData->items.size() && layoutData->items.at(itemToSplit).position <= strPos)
2627         itemToSplit++;
2628     itemToSplit--;
2629     if (layoutData->items.at(itemToSplit).position == strPos) {
2630         // already a split at the requested position
2631         return;
2632     }
2633     splitItem(itemToSplit, strPos - layoutData->items.at(itemToSplit).position);
2634 }
2635
2636 void QTextEngine::splitItem(int item, int pos) const
2637 {
2638     if (pos <= 0)
2639         return;
2640
2641     layoutData->items.insert(item + 1, layoutData->items[item]);
2642     QScriptItem &oldItem = layoutData->items[item];
2643     QScriptItem &newItem = layoutData->items[item+1];
2644     newItem.position += pos;
2645
2646     if (oldItem.num_glyphs) {
2647         // already shaped, break glyphs aswell
2648         int breakGlyph = logClusters(&oldItem)[pos];
2649
2650         newItem.num_glyphs = oldItem.num_glyphs - breakGlyph;
2651         oldItem.num_glyphs = breakGlyph;
2652         newItem.glyph_data_offset = oldItem.glyph_data_offset + breakGlyph;
2653
2654         for (int i = 0; i < newItem.num_glyphs; i++)
2655             logClusters(&newItem)[i] -= breakGlyph;
2656
2657         QFixed w = 0;
2658         const QGlyphLayout g = shapedGlyphs(&oldItem);
2659         for(int j = 0; j < breakGlyph; ++j)
2660             w += g.advances_x[j];
2661
2662         newItem.width = oldItem.width - w;
2663         oldItem.width = w;
2664     }
2665
2666 //     qDebug("split at position %d itempos=%d", pos, item);
2667 }
2668
2669 QFixed QTextEngine::calculateTabWidth(int item, QFixed x) const
2670 {
2671     const QScriptItem &si = layoutData->items[item];
2672
2673     QFixed dpiScale = 1;
2674     if (block.docHandle() && block.docHandle()->layout()) {
2675         QPaintDevice *pdev = block.docHandle()->layout()->paintDevice();
2676         if (pdev)
2677             dpiScale = QFixed::fromReal(pdev->logicalDpiY() / qreal(qt_defaultDpiY()));
2678     } else {
2679         dpiScale = QFixed::fromReal(fnt.d->dpi / qreal(qt_defaultDpiY()));
2680     }
2681
2682     QList<QTextOption::Tab> tabArray = option.tabs();
2683     if (!tabArray.isEmpty()) {
2684         if (isRightToLeft()) { // rebase the tabArray positions.
2685             QList<QTextOption::Tab> newTabs;
2686             QList<QTextOption::Tab>::Iterator iter = tabArray.begin();
2687             while(iter != tabArray.end()) {
2688                 QTextOption::Tab tab = *iter;
2689                 if (tab.type == QTextOption::LeftTab)
2690                     tab.type = QTextOption::RightTab;
2691                 else if (tab.type == QTextOption::RightTab)
2692                     tab.type = QTextOption::LeftTab;
2693                 newTabs << tab;
2694                 ++iter;
2695             }
2696             tabArray = newTabs;
2697         }
2698         for (int i = 0; i < tabArray.size(); ++i) {
2699             QFixed tab = QFixed::fromReal(tabArray[i].position) * dpiScale;
2700             if (tab > x) {  // this is the tab we need.
2701                 QTextOption::Tab tabSpec = tabArray[i];
2702                 int tabSectionEnd = layoutData->string.count();
2703                 if (tabSpec.type == QTextOption::RightTab || tabSpec.type == QTextOption::CenterTab) {
2704                     // find next tab to calculate the width required.
2705                     tab = QFixed::fromReal(tabSpec.position);
2706                     for (int i=item + 1; i < layoutData->items.count(); i++) {
2707                         const QScriptItem &item = layoutData->items[i];
2708                         if (item.analysis.flags == QScriptAnalysis::TabOrObject) { // found it.
2709                             tabSectionEnd = item.position;
2710                             break;
2711                         }
2712                     }
2713                 }
2714                 else if (tabSpec.type == QTextOption::DelimiterTab)
2715                     // find delimitor character to calculate the width required
2716                     tabSectionEnd = qMax(si.position, layoutData->string.indexOf(tabSpec.delimiter, si.position) + 1);
2717
2718                 if (tabSectionEnd > si.position) {
2719                     QFixed length;
2720                     // Calculate the length of text between this tab and the tabSectionEnd
2721                     for (int i=item; i < layoutData->items.count(); i++) {
2722                         QScriptItem &item = layoutData->items[i];
2723                         if (item.position > tabSectionEnd || item.position <= si.position)
2724                             continue;
2725                         shape(i); // first, lets make sure relevant text is already shaped
2726                         QGlyphLayout glyphs = this->shapedGlyphs(&item);
2727                         const int end = qMin(item.position + item.num_glyphs, tabSectionEnd) - item.position;
2728                         for (int i=0; i < end; i++)
2729                             length += glyphs.advances_x[i] * !glyphs.attributes[i].dontPrint;
2730                         if (end + item.position == tabSectionEnd && tabSpec.type == QTextOption::DelimiterTab) // remove half of matching char
2731                             length -= glyphs.advances_x[end] / 2 * !glyphs.attributes[end].dontPrint;
2732                     }
2733
2734                     switch (tabSpec.type) {
2735                     case QTextOption::CenterTab:
2736                         length /= 2;
2737                         // fall through
2738                     case QTextOption::DelimiterTab:
2739                         // fall through
2740                     case QTextOption::RightTab:
2741                         tab = QFixed::fromReal(tabSpec.position) * dpiScale - length;
2742                         if (tab < 0) // default to tab taking no space
2743                             return QFixed();
2744                         break;
2745                     case QTextOption::LeftTab:
2746                         break;
2747                     }
2748                 }
2749                 return tab - x;
2750             }
2751         }
2752     }
2753     QFixed tab = QFixed::fromReal(option.tabStop());
2754     if (tab <= 0)
2755         tab = 80; // default
2756     tab *= dpiScale;
2757     QFixed nextTabPos = ((x / tab).truncate() + 1) * tab;
2758     QFixed tabWidth = nextTabPos - x;
2759
2760     return tabWidth;
2761 }
2762
2763 void QTextEngine::resolveAdditionalFormats() const
2764 {
2765     if (!specialData || specialData->addFormats.isEmpty()
2766         || !block.docHandle()
2767         || !specialData->resolvedFormatIndices.isEmpty())
2768         return;
2769
2770     QTextFormatCollection *collection = this->formats();
2771
2772     specialData->resolvedFormatIndices.clear();
2773     QVector<int> indices(layoutData->items.count());
2774     for (int i = 0; i < layoutData->items.count(); ++i) {
2775         QTextCharFormat f = format(&layoutData->items.at(i));
2776         indices[i] = collection->indexForFormat(f);
2777     }
2778     specialData->resolvedFormatIndices = indices;
2779 }
2780
2781 QFixed QTextEngine::leadingSpaceWidth(const QScriptLine &line)
2782 {
2783     if (!line.hasTrailingSpaces
2784         || (option.flags() & QTextOption::IncludeTrailingSpaces)
2785         || !isRightToLeft())
2786         return QFixed();
2787
2788     int pos = line.length;
2789     const HB_CharAttributes *attributes = this->attributes();
2790     if (!attributes)
2791         return QFixed();
2792     while (pos > 0 && attributes[line.from + pos - 1].whiteSpace)
2793         --pos;
2794     return width(line.from + pos, line.length - pos);
2795 }
2796
2797 QFixed QTextEngine::alignLine(const QScriptLine &line)
2798 {
2799     QFixed x = 0;
2800     justify(line);
2801     // if width is QFIXED_MAX that means we used setNumColumns() and that implicitly makes this line left aligned.
2802     if (!line.justified && line.width != QFIXED_MAX) {
2803         int align = option.alignment();
2804         if (align & Qt::AlignLeft)
2805             x -= leadingSpaceWidth(line);
2806         if (align & Qt::AlignJustify && isRightToLeft())
2807             align = Qt::AlignRight;
2808         if (align & Qt::AlignRight)
2809             x = line.width - (line.textAdvance + leadingSpaceWidth(line));
2810         else if (align & Qt::AlignHCenter)
2811             x = (line.width - line.textAdvance)/2 - leadingSpaceWidth(line);
2812     }
2813     return x;
2814 }
2815
2816 QFixed QTextEngine::offsetInLigature(const QScriptItem *si, int pos, int max, int glyph_pos)
2817 {
2818     unsigned short *logClusters = this->logClusters(si);
2819     const QGlyphLayout &glyphs = shapedGlyphs(si);
2820
2821     int offsetInCluster = 0;
2822     for (int i = pos - 1; i >= 0; i--) {
2823         if (logClusters[i] == glyph_pos)
2824             offsetInCluster++;
2825         else
2826             break;
2827     }
2828
2829     // in the case that the offset is inside a (multi-character) glyph,
2830     // interpolate the position.
2831     if (offsetInCluster > 0) {
2832         int clusterLength = 0;
2833         for (int i = pos - offsetInCluster; i < max; i++) {
2834             if (logClusters[i] == glyph_pos)
2835                 clusterLength++;
2836             else
2837                 break;
2838         }
2839         if (clusterLength)
2840             return glyphs.advances_x[glyph_pos] * offsetInCluster / clusterLength;
2841     }
2842
2843     return 0;
2844 }
2845
2846 // Scan in logClusters[from..to-1] for glyph_pos
2847 int QTextEngine::getClusterLength(unsigned short *logClusters,
2848                                   const HB_CharAttributes *attributes,
2849                                   int from, int to, int glyph_pos, int *start)
2850 {
2851     int clusterLength = 0;
2852     for (int i = from; i < to; i++) {
2853         if (logClusters[i] == glyph_pos && attributes[i].charStop) {
2854             if (*start < 0)
2855                 *start = i;
2856             clusterLength++;
2857         }
2858         else if (clusterLength)
2859             break;
2860     }
2861     return clusterLength;
2862 }
2863
2864 int QTextEngine::positionInLigature(const QScriptItem *si, int end,
2865                                     QFixed x, QFixed edge, int glyph_pos,
2866                                     bool cursorOnCharacter)
2867 {
2868     unsigned short *logClusters = this->logClusters(si);
2869     int clusterStart = -1;
2870     int clusterLength = 0;
2871
2872     if (si->analysis.script != QUnicodeTables::Common &&
2873         si->analysis.script != QUnicodeTables::Greek) {
2874         if (glyph_pos == -1)
2875             return si->position + end;
2876         else {
2877             int i;
2878             for (i = 0; i < end; i++)
2879                 if (logClusters[i] == glyph_pos)
2880                     break;
2881             return si->position + i;
2882         }
2883     }
2884
2885     if (glyph_pos == -1 && end > 0)
2886         glyph_pos = logClusters[end - 1];
2887     else {
2888         if (x <= edge)
2889             glyph_pos--;
2890     }
2891
2892     const HB_CharAttributes *attrs = attributes();
2893     logClusters = this->logClusters(si);
2894     clusterLength = getClusterLength(logClusters, attrs, 0, end, glyph_pos, &clusterStart);
2895
2896     if (clusterLength) {
2897         const QGlyphLayout &glyphs = shapedGlyphs(si);
2898         QFixed glyphWidth = glyphs.effectiveAdvance(glyph_pos);
2899         // the approximate width of each individual element of the ligature
2900         QFixed perItemWidth = glyphWidth / clusterLength;
2901         QFixed left = x > edge ? edge : edge - glyphWidth;
2902         int n = ((x - left) / perItemWidth).floor().toInt();
2903         QFixed dist = x - left - n * perItemWidth;
2904         int closestItem = dist > (perItemWidth / 2) ? n + 1 : n;
2905         if (cursorOnCharacter && closestItem > 0)
2906             closestItem--;
2907         int pos = si->position + clusterStart + closestItem;
2908         // Jump to the next charStop
2909         while (!attrs[pos].charStop && pos < end)
2910             pos++;
2911         return pos;
2912     }
2913     return si->position + end;
2914 }
2915
2916 int QTextEngine::previousLogicalPosition(int oldPos) const
2917 {
2918     const HB_CharAttributes *attrs = attributes();
2919     if (!attrs || oldPos < 0)
2920         return oldPos;
2921
2922     if (oldPos <= 0)
2923         return 0;
2924     oldPos--;
2925     while (oldPos && !attrs[oldPos].charStop)
2926         oldPos--;
2927     return oldPos;
2928 }
2929
2930 int QTextEngine::nextLogicalPosition(int oldPos) const
2931 {
2932     const HB_CharAttributes *attrs = attributes();
2933     int len = block.isValid() ? block.length() - 1
2934                               : layoutData->string.length();
2935     Q_ASSERT(len <= layoutData->string.length());
2936     if (!attrs || oldPos < 0 || oldPos >= len)
2937         return oldPos;
2938
2939     oldPos++;
2940     while (oldPos < len && !attrs[oldPos].charStop)
2941         oldPos++;
2942     return oldPos;
2943 }
2944
2945 int QTextEngine::lineNumberForTextPosition(int pos)
2946 {
2947     if (!layoutData)
2948         itemize();
2949     if (pos == layoutData->string.length() && lines.size())
2950         return lines.size() - 1;
2951     for (int i = 0; i < lines.size(); ++i) {
2952         const QScriptLine& line = lines[i];
2953         if (line.from + line.length > pos)
2954             return i;
2955     }
2956     return -1;
2957 }
2958
2959 void QTextEngine::insertionPointsForLine(int lineNum, QVector<int> &insertionPoints)
2960 {
2961     QTextLineItemIterator iterator(this, lineNum);
2962     bool rtl = isRightToLeft();
2963     bool lastLine = lineNum >= lines.size() - 1;
2964
2965     while (!iterator.atEnd()) {
2966         iterator.next();
2967         const QScriptItem *si = &layoutData->items[iterator.item];
2968         if (si->analysis.bidiLevel % 2) {
2969             int i = iterator.itemEnd - 1, min = iterator.itemStart;
2970             if (lastLine && (rtl ? iterator.atBeginning() : iterator.atEnd()))
2971                 i++;
2972             for (; i >= min; i--)
2973                 insertionPoints.push_back(i);
2974         } else {
2975             int i = iterator.itemStart, max = iterator.itemEnd;
2976             if (lastLine && (rtl ? iterator.atBeginning() : iterator.atEnd()))
2977                 max++;
2978             for (; i < max; i++)
2979                 insertionPoints.push_back(i);
2980         }
2981     }
2982 }
2983
2984 int QTextEngine::endOfLine(int lineNum)
2985 {
2986     QVector<int> insertionPoints;
2987     insertionPointsForLine(lineNum, insertionPoints);
2988
2989     if (insertionPoints.size() > 0)
2990         return insertionPoints.last();
2991     return 0;
2992 }
2993
2994 int QTextEngine::beginningOfLine(int lineNum)
2995 {
2996     QVector<int> insertionPoints;
2997     insertionPointsForLine(lineNum, insertionPoints);
2998
2999     if (insertionPoints.size() > 0)
3000         return insertionPoints.first();
3001     return 0;
3002 }
3003
3004 int QTextEngine::positionAfterVisualMovement(int pos, QTextCursor::MoveOperation op)
3005 {
3006     if (!layoutData)
3007         itemize();
3008
3009     bool moveRight = (op == QTextCursor::Right);
3010     bool alignRight = isRightToLeft();
3011     if (!layoutData->hasBidi)
3012         return moveRight ^ alignRight ? nextLogicalPosition(pos) : previousLogicalPosition(pos);
3013
3014     int lineNum = lineNumberForTextPosition(pos);
3015     Q_ASSERT(lineNum >= 0);
3016
3017     QVector<int> insertionPoints;
3018     insertionPointsForLine(lineNum, insertionPoints);
3019     int i, max = insertionPoints.size();
3020     for (i = 0; i < max; i++)
3021         if (pos == insertionPoints[i]) {
3022             if (moveRight) {
3023                 if (i + 1 < max)
3024                     return insertionPoints[i + 1];
3025             } else {
3026                 if (i > 0)
3027                     return insertionPoints[i - 1];
3028             }
3029
3030             if (moveRight ^ alignRight) {
3031                 if (lineNum + 1 < lines.size())
3032                     return alignRight ? endOfLine(lineNum + 1) : beginningOfLine(lineNum + 1);
3033             }
3034             else {
3035                 if (lineNum > 0)
3036                     return alignRight ? beginningOfLine(lineNum - 1) : endOfLine(lineNum - 1);
3037             }
3038         }
3039
3040     return pos;
3041 }
3042
3043 QStackTextEngine::QStackTextEngine(const QString &string, const QFont &f)
3044     : QTextEngine(string, f),
3045       _layoutData(string, _memory, MemSize)
3046 {
3047     stackEngine = true;
3048     layoutData = &_layoutData;
3049 }
3050
3051 QTextItemInt::QTextItemInt(const QScriptItem &si, QFont *font, const QTextCharFormat &format)
3052     : justified(false), underlineStyle(QTextCharFormat::NoUnderline), charFormat(format),
3053       num_chars(0), chars(0), logClusters(0), f(0), fontEngine(0)
3054 {
3055     f = font;
3056     fontEngine = f->d->engineForScript(si.analysis.script);
3057     Q_ASSERT(fontEngine);
3058
3059     initWithScriptItem(si);
3060 }
3061
3062 QTextItemInt::QTextItemInt(const QGlyphLayout &g, QFont *font, const QChar *chars_, int numChars, QFontEngine *fe, const QTextCharFormat &format)
3063     : flags(0), justified(false), underlineStyle(QTextCharFormat::NoUnderline), charFormat(format),
3064       num_chars(numChars), chars(chars_), logClusters(0), f(font),  glyphs(g), fontEngine(fe)
3065 {
3066 }
3067
3068 // Fix up flags and underlineStyle with given info
3069 void QTextItemInt::initWithScriptItem(const QScriptItem &si)
3070 {
3071     // explicitly initialize flags so that initFontAttributes can be called
3072     // multiple times on the same TextItem
3073     flags = 0;
3074     if (si.analysis.bidiLevel %2)
3075         flags |= QTextItem::RightToLeft;
3076     ascent = si.ascent;
3077     descent = si.descent;
3078
3079     if (charFormat.hasProperty(QTextFormat::TextUnderlineStyle)) {
3080         underlineStyle = charFormat.underlineStyle();
3081     } else if (charFormat.boolProperty(QTextFormat::FontUnderline)
3082                || f->d->underline) {
3083         underlineStyle = QTextCharFormat::SingleUnderline;
3084     }
3085
3086     // compat
3087     if (underlineStyle == QTextCharFormat::SingleUnderline)
3088         flags |= QTextItem::Underline;
3089
3090     if (f->d->overline || charFormat.fontOverline())
3091         flags |= QTextItem::Overline;
3092     if (f->d->strikeOut || charFormat.fontStrikeOut())
3093         flags |= QTextItem::StrikeOut;
3094 }
3095
3096 QTextItemInt QTextItemInt::midItem(QFontEngine *fontEngine, int firstGlyphIndex, int numGlyphs) const
3097 {
3098     QTextItemInt ti = *this;
3099     const int end = firstGlyphIndex + numGlyphs;
3100     ti.glyphs = glyphs.mid(firstGlyphIndex, numGlyphs);
3101     ti.fontEngine = fontEngine;
3102
3103     if (logClusters && chars) {
3104         const int logClusterOffset = logClusters[0];
3105         while (logClusters[ti.chars - chars] - logClusterOffset < firstGlyphIndex)
3106             ++ti.chars;
3107
3108         ti.logClusters += (ti.chars - chars);
3109
3110         ti.num_chars = 0;
3111         int char_start = ti.chars - chars;
3112         while (char_start + ti.num_chars < num_chars && ti.logClusters[ti.num_chars] - logClusterOffset < end)
3113             ++ti.num_chars;
3114     }
3115     return ti;
3116 }
3117
3118
3119 QTransform qt_true_matrix(qreal w, qreal h, QTransform x)
3120 {
3121     QRectF rect = x.mapRect(QRectF(0, 0, w, h));
3122     return x * QTransform::fromTranslate(-rect.x(), -rect.y());
3123 }
3124
3125
3126 glyph_metrics_t glyph_metrics_t::transformed(const QTransform &matrix) const
3127 {
3128     if (matrix.type() < QTransform::TxTranslate)
3129         return *this;
3130
3131     glyph_metrics_t m = *this;
3132
3133     qreal w = width.toReal();
3134     qreal h = height.toReal();
3135     QTransform xform = qt_true_matrix(w, h, matrix);
3136
3137     QRectF rect(0, 0, w, h);
3138     rect = xform.mapRect(rect);
3139     m.width = QFixed::fromReal(rect.width());
3140     m.height = QFixed::fromReal(rect.height());
3141
3142     QLineF l = xform.map(QLineF(x.toReal(), y.toReal(), xoff.toReal(), yoff.toReal()));
3143
3144     m.x = QFixed::fromReal(l.x1());
3145     m.y = QFixed::fromReal(l.y1());
3146
3147     // The offset is relative to the baseline which is why we use dx/dy of the line
3148     m.xoff = QFixed::fromReal(l.dx());
3149     m.yoff = QFixed::fromReal(l.dy());
3150
3151     return m;
3152 }
3153
3154 QTextLineItemIterator::QTextLineItemIterator(QTextEngine *_eng, int _lineNum, const QPointF &pos,
3155                                              const QTextLayout::FormatRange *_selection)
3156     : eng(_eng),
3157       line(eng->lines[_lineNum]),
3158       si(0),
3159       lineNum(_lineNum),
3160       lineEnd(line.from + line.length),
3161       firstItem(eng->findItem(line.from)),
3162       lastItem(eng->findItem(lineEnd - 1)),
3163       nItems((firstItem >= 0 && lastItem >= firstItem)? (lastItem-firstItem+1) : 0),
3164       logicalItem(-1),
3165       item(-1),
3166       visualOrder(nItems),
3167       levels(nItems),
3168       selection(_selection)
3169 {
3170     pos_x = x = QFixed::fromReal(pos.x());
3171
3172     x += line.x;
3173
3174     x += eng->alignLine(line);
3175
3176     for (int i = 0; i < nItems; ++i)
3177         levels[i] = eng->layoutData->items[i+firstItem].analysis.bidiLevel;
3178     QTextEngine::bidiReorder(nItems, levels.data(), visualOrder.data());
3179
3180     eng->shapeLine(line);
3181 }
3182
3183 QScriptItem &QTextLineItemIterator::next()
3184 {
3185     x += itemWidth;
3186
3187     ++logicalItem;
3188     item = visualOrder[logicalItem] + firstItem;
3189     itemLength = eng->length(item);
3190     si = &eng->layoutData->items[item];
3191     if (!si->num_glyphs)
3192         eng->shape(item);
3193
3194     if (si->analysis.flags >= QScriptAnalysis::TabOrObject) {
3195         itemWidth = si->width;
3196         return *si;
3197     }
3198
3199     unsigned short *logClusters = eng->logClusters(si);
3200     QGlyphLayout glyphs = eng->shapedGlyphs(si);
3201
3202     itemStart = qMax(line.from, si->position);
3203     glyphsStart = logClusters[itemStart - si->position];
3204     if (lineEnd < si->position + itemLength) {
3205         itemEnd = lineEnd;
3206         glyphsEnd = logClusters[itemEnd-si->position];
3207     } else {
3208         itemEnd = si->position + itemLength;
3209         glyphsEnd = si->num_glyphs;
3210     }
3211     // show soft-hyphen at line-break
3212     if (si->position + itemLength >= lineEnd
3213         && eng->layoutData->string.at(lineEnd - 1) == 0x00ad)
3214         glyphs.attributes[glyphsEnd - 1].dontPrint = false;
3215
3216     itemWidth = 0;
3217     for (int g = glyphsStart; g < glyphsEnd; ++g)
3218         itemWidth += glyphs.effectiveAdvance(g);
3219
3220     return *si;
3221 }
3222
3223 bool QTextLineItemIterator::getSelectionBounds(QFixed *selectionX, QFixed *selectionWidth) const
3224 {
3225     *selectionX = *selectionWidth = 0;
3226
3227     if (!selection)
3228         return false;
3229
3230     if (si->analysis.flags >= QScriptAnalysis::TabOrObject) {
3231         if (si->position >= selection->start + selection->length
3232             || si->position + itemLength <= selection->start)
3233             return false;
3234
3235         *selectionX = x;
3236         *selectionWidth = itemWidth;
3237     } else {
3238         unsigned short *logClusters = eng->logClusters(si);
3239         QGlyphLayout glyphs = eng->shapedGlyphs(si);
3240
3241         int from = qMax(itemStart, selection->start) - si->position;
3242         int to = qMin(itemEnd, selection->start + selection->length) - si->position;
3243         if (from >= to)
3244             return false;
3245
3246         int start_glyph = logClusters[from];
3247         int end_glyph = (to == eng->length(item)) ? si->num_glyphs : logClusters[to];
3248         QFixed soff;
3249         QFixed swidth;
3250         if (si->analysis.bidiLevel %2) {
3251             for (int g = glyphsEnd - 1; g >= end_glyph; --g)
3252                 soff += glyphs.effectiveAdvance(g);
3253             for (int g = end_glyph - 1; g >= start_glyph; --g)
3254                 swidth += glyphs.effectiveAdvance(g);
3255         } else {
3256             for (int g = glyphsStart; g < start_glyph; ++g)
3257                 soff += glyphs.effectiveAdvance(g);
3258             for (int g = start_glyph; g < end_glyph; ++g)
3259                 swidth += glyphs.effectiveAdvance(g);
3260         }
3261
3262         // If the starting character is in the middle of a ligature,
3263         // selection should only contain the right part of that ligature
3264         // glyph, so we need to get the width of the left part here and
3265         // add it to *selectionX
3266         QFixed leftOffsetInLigature = eng->offsetInLigature(si, from, to, start_glyph);
3267         *selectionX = x + soff + leftOffsetInLigature;
3268         *selectionWidth = swidth - leftOffsetInLigature;
3269         // If the ending character is also part of a ligature, swidth does
3270         // not contain that part yet, we also need to find out the width of
3271         // that left part
3272         *selectionWidth += eng->offsetInLigature(si, to, eng->length(item), end_glyph);
3273     }
3274     return true;
3275 }
3276
3277 QT_END_NAMESPACE