source: trunk/src/kernel/qtextlayout.cpp@ 94

Last change on this file since 94 was 2, checked in by dmik, 20 years ago

Imported xplatform parts of the official release 3.3.1 from Trolltech
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File size: 16.9 KB
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1/****************************************************************************
2** $Id: qtextlayout.cpp 2 2005-11-16 15:49:26Z dmik $
3**
4** ???
5**
6** Copyright (C) 2003 Trolltech AS. All rights reserved.
7**
8** This file is part of the kernel module of the Qt GUI Toolkit.
9**
10** This file may be distributed under the terms of the Q Public License
11** as defined by Trolltech AS of Norway and appearing in the file
12** LICENSE.QPL included in the packaging of this file.
13**
14** This file may be distributed and/or modified under the terms of the
15** GNU General Public License version 2 as published by the Free Software
16** Foundation and appearing in the file LICENSE.GPL included in the
17** packaging of this file.
18**
19** Licensees holding valid Qt Enterprise Edition or Qt Professional Edition
20** licenses may use this file in accordance with the Qt Commercial License
21** Agreement provided with the Software.
22**
23** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
24** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
25**
26** See http://www.trolltech.com/pricing.html or email sales@trolltech.com for
27** information about Qt Commercial License Agreements.
28** See http://www.trolltech.com/qpl/ for QPL licensing information.
29** See http://www.trolltech.com/gpl/ for GPL licensing information.
30**
31** Contact info@trolltech.com if any conditions of this licensing are
32** not clear to you.
33**
34**********************************************************************/
35
36#include "qtextlayout_p.h"
37#include "qtextengine_p.h"
38
39#include <qfont.h>
40#include <qapplication.h>
41#include <qpainter.h>
42
43
44QRect QTextItem::rect() const
45{
46 QScriptItem& si = engine->items[item];
47 return QRect( si.x, si.y, si.width, si.ascent+si.descent );
48}
49
50int QTextItem::x() const
51{
52 return engine->items[item].x;
53}
54
55int QTextItem::y() const
56{
57 return engine->items[item].y;
58}
59
60int QTextItem::width() const
61{
62 return engine->items[item].width;
63}
64
65int QTextItem::ascent() const
66{
67 return engine->items[item].ascent;
68}
69
70int QTextItem::descent() const
71{
72 return engine->items[item].descent;
73}
74
75void QTextItem::setWidth( int w )
76{
77 engine->items[item].width = w;
78}
79
80void QTextItem::setAscent( int a )
81{
82 engine->items[item].ascent = a;
83}
84
85void QTextItem::setDescent( int d )
86{
87 engine->items[item].descent = d;
88}
89
90int QTextItem::from() const
91{
92 return engine->items[item].position;
93}
94
95int QTextItem::length() const
96{
97 return engine->length(item);
98}
99
100
101int QTextItem::cursorToX( int *cPos, Edge edge ) const
102{
103 int pos = *cPos;
104 QScriptItem *si = &engine->items[item];
105
106 engine->shape( item );
107 advance_t *advances = engine->advances( si );
108 GlyphAttributes *glyphAttributes = engine->glyphAttributes( si );
109 unsigned short *logClusters = engine->logClusters( si );
110
111 int l = engine->length( item );
112 if ( pos > l )
113 pos = l;
114 if ( pos < 0 )
115 pos = 0;
116
117 int glyph_pos = pos == l ? si->num_glyphs : logClusters[pos];
118 if ( edge == Trailing ) {
119 // trailing edge is leading edge of next cluster
120 while ( glyph_pos < si->num_glyphs && !glyphAttributes[glyph_pos].clusterStart )
121 glyph_pos++;
122 }
123
124 int x = 0;
125 bool reverse = engine->items[item].analysis.bidiLevel % 2;
126
127 if ( reverse ) {
128 for ( int i = si->num_glyphs-1; i >= glyph_pos; i-- )
129 x += advances[i];
130 } else {
131 for ( int i = 0; i < glyph_pos; i++ )
132 x += advances[i];
133 }
134// qDebug("cursorToX: pos=%d, gpos=%d x=%d", pos, glyph_pos, x );
135 *cPos = pos;
136 return x;
137}
138
139int QTextItem::xToCursor( int x, CursorPosition cpos ) const
140{
141 QScriptItem *si = &engine->items[item];
142 engine->shape( item );
143 advance_t *advances = engine->advances( si );
144 unsigned short *logClusters = engine->logClusters( si );
145
146 int l = engine->length( item );
147 bool reverse = si->analysis.bidiLevel % 2;
148 if ( x < 0 )
149 return reverse ? l : 0;
150
151
152 if ( reverse ) {
153 int width = 0;
154 for ( int i = 0; i < si->num_glyphs; i++ ) {
155 width += advances[i];
156 }
157 x = -x + width;
158 }
159 int cp_before = 0;
160 int cp_after = 0;
161 int x_before = 0;
162 int x_after = 0;
163
164 int lastCluster = 0;
165 for ( int i = 1; i <= l; i++ ) {
166 int newCluster = i < l ? logClusters[i] : si->num_glyphs;
167 if ( newCluster != lastCluster ) {
168 // calculate cluster width
169 cp_before = cp_after;
170 x_before = x_after;
171 cp_after = i;
172 for ( int j = lastCluster; j < newCluster; j++ )
173 x_after += advances[j];
174 // qDebug("cluster boundary: lastCluster=%d, newCluster=%d, x_before=%d, x_after=%d",
175 // lastCluster, newCluster, x_before, x_after );
176 if ( x_after > x )
177 break;
178 lastCluster = newCluster;
179 }
180 }
181
182 bool before = ( cpos == OnCharacters || (x - x_before) < (x_after - x) );
183
184// qDebug("got cursor position for %d: %d/%d, x_ba=%d/%d using %d",
185// x, cp_before,cp_after, x_before, x_after, before ? cp_before : cp_after );
186
187 return before ? cp_before : cp_after;
188
189}
190
191
192bool QTextItem::isRightToLeft() const
193{
194 return (engine->items[item].analysis.bidiLevel % 2);
195}
196
197bool QTextItem::isObject() const
198{
199 return engine->items[item].isObject;
200}
201
202bool QTextItem::isSpace() const
203{
204 return engine->items[item].isSpace;
205}
206
207bool QTextItem::isTab() const
208{
209 return engine->items[item].isTab;
210}
211
212
213QTextLayout::QTextLayout()
214 :d(0) {}
215
216QTextLayout::QTextLayout( const QString& string, QPainter *p )
217{
218 QFontPrivate *f = p ? ( p->pfont ? p->pfont->d : p->cfont.d ) : QApplication::font().d;
219 d = new QTextEngine( (string.isNull() ? (const QString&)QString::fromLatin1("") : string), f );
220}
221
222QTextLayout::QTextLayout( const QString& string, const QFont& fnt )
223{
224 d = new QTextEngine( (string.isNull() ? (const QString&)QString::fromLatin1("") : string), fnt.d );
225}
226
227QTextLayout::~QTextLayout()
228{
229 delete d;
230}
231
232void QTextLayout::setText( const QString& string, const QFont& fnt )
233{
234 delete d;
235 d = new QTextEngine( (string.isNull() ? (const QString&)QString::fromLatin1("") : string), fnt.d );
236}
237
238/* add an additional item boundary eg. for style change */
239void QTextLayout::setBoundary( int strPos )
240{
241 if ( strPos <= 0 || strPos >= (int)d->string.length() )
242 return;
243
244 int itemToSplit = 0;
245 while ( itemToSplit < d->items.size() && d->items[itemToSplit].position <= strPos )
246 itemToSplit++;
247 itemToSplit--;
248 if ( d->items[itemToSplit].position == strPos ) {
249 // already a split at the requested position
250 return;
251 }
252 d->splitItem( itemToSplit, strPos - d->items[itemToSplit].position );
253}
254
255
256int QTextLayout::numItems() const
257{
258 return d->items.size();
259}
260
261QTextItem QTextLayout::itemAt( int i ) const
262{
263 return QTextItem( i, d );
264}
265
266
267QTextItem QTextLayout::findItem( int strPos ) const
268{
269 if ( strPos == 0 && d->items.size() )
270 return QTextItem( 0, d );
271 // ## TODO use bsearch
272 for ( int i = d->items.size()-1; i >= 0; --i ) {
273 if ( d->items[i].position < strPos )
274 return QTextItem( i, d );
275 }
276 return QTextItem();
277}
278
279
280void QTextLayout::beginLayout( QTextLayout::LayoutMode m )
281{
282 d->items.clear();
283 QTextEngine::Mode mode = QTextEngine::Full;
284 if (m == NoBidi)
285 mode = QTextEngine::NoBidi;
286 else if (m == SingleLine)
287 mode = QTextEngine::SingleLine;
288 d->itemize( mode );
289 d->currentItem = 0;
290 d->firstItemInLine = -1;
291}
292
293void QTextLayout::beginLine( int width )
294{
295 d->lineWidth = width;
296 d->widthUsed = 0;
297 d->firstItemInLine = -1;
298}
299
300bool QTextLayout::atEnd() const
301{
302 return d->currentItem >= d->items.size();
303}
304
305QTextItem QTextLayout::nextItem()
306{
307 d->currentItem++;
308
309 if ( d->currentItem >= d->items.size() )
310 return QTextItem();
311
312 d->shape( d->currentItem );
313 return QTextItem( d->currentItem, d );
314}
315
316QTextItem QTextLayout::currentItem()
317{
318 if ( d->currentItem >= d->items.size() )
319 return QTextItem();
320
321 d->shape( d->currentItem );
322 return QTextItem( d->currentItem, d );
323}
324
325/* ## maybe also currentItem() */
326void QTextLayout::setLineWidth( int newWidth )
327{
328 d->lineWidth = newWidth;
329}
330
331int QTextLayout::lineWidth() const
332{
333 return d->lineWidth;
334}
335
336int QTextLayout::widthUsed() const
337{
338 return d->widthUsed;
339}
340
341int QTextLayout::availableWidth() const
342{
343 return d->lineWidth - d->widthUsed;
344}
345
346
347/* returns true if completely added */
348QTextLayout::Result QTextLayout::addCurrentItem()
349{
350 if ( d->firstItemInLine == -1 )
351 d->firstItemInLine = d->currentItem;
352 QScriptItem &current = d->items[d->currentItem];
353 d->shape( d->currentItem );
354 d->widthUsed += current.width;
355// qDebug("trying to add item %d with width %d, remaining %d", d->currentItem, current.width, d->lineWidth-d->widthUsed );
356
357 d->currentItem++;
358
359 return (d->widthUsed <= d->lineWidth
360 || (d->currentItem < d->items.size() && d->items[d->currentItem].isSpace)) ? Ok : LineFull;
361}
362
363QTextLayout::Result QTextLayout::endLine( int x, int y, int alignment,
364 int *ascent, int *descent, int *lineLeft, int *lineRight )
365{
366 int available = d->lineWidth;
367 int numRuns = 0;
368 int numSpaceItems = 0;
369 Q_UINT8 _levels[128];
370 int _visual[128];
371 Q_UINT8 *levels = _levels;
372 int *visual = _visual;
373 int i;
374 QTextLayout::Result result = LineEmpty;
375
376// qDebug("endLine x=%d, y=%d, first=%d, current=%d lw=%d wu=%d", x, y, d->firstItemInLine, d->currentItem, d->lineWidth, d->widthUsed );
377 if ( d->firstItemInLine == -1 )
378 goto end;
379
380 if ( !(alignment & (Qt::SingleLine|Qt::IncludeTrailingSpaces))
381 && d->currentItem > d->firstItemInLine && d->items[d->currentItem-1].isSpace ) {
382 int i = d->currentItem-1;
383 while ( i > d->firstItemInLine && d->items[i].isSpace ) {
384 numSpaceItems++;
385 d->widthUsed -= d->items[i--].width;
386 }
387 }
388
389 if ( (alignment & (Qt::WordBreak|Qt::BreakAnywhere)) &&
390 d->widthUsed > d->lineWidth ) {
391 // find linebreak
392
393 // even though we removed trailing spaces the line was too wide. We'll have to break at an earlier
394 // position. To not confuse the layouting below, reset the number of space items
395 numSpaceItems = 0;
396
397
398 bool breakany = alignment & Qt::BreakAnywhere;
399
400 const QCharAttributes *attrs = d->attributes();
401 int w = 0;
402 int itemWidth = 0;
403 int breakItem = d->firstItemInLine;
404 int breakPosition = -1;
405#if 0
406 // we iterate backwards or forward depending on what we guess is closer
407 if ( d->widthUsed - d->lineWidth < d->lineWidth ) {
408 // backwards search should be faster
409
410 } else
411#endif
412 {
413 int tmpWidth = 0;
414 int swidth = 0;
415 // forward search is probably faster
416 for ( int i = d->firstItemInLine; i < d->currentItem; i++ ) {
417 const QScriptItem *si = &d->items[i];
418 int length = d->length( i );
419 const QCharAttributes *itemAttrs = attrs + si->position;
420
421 advance_t *advances = d->advances( si );
422 unsigned short *logClusters = d->logClusters( si );
423
424 int lastGlyph = 0;
425 int tmpItemWidth = 0;
426
427// qDebug("looking for break in item %d, isSpace=%d", i, si->isSpace );
428 if(si->isSpace && !(alignment & (Qt::SingleLine|Qt::IncludeTrailingSpaces))) {
429 swidth += si->width;
430 } else {
431 tmpWidth += swidth;
432 swidth = 0;
433 for ( int pos = 0; pos < length; pos++ ) {
434 //qDebug("advance=%d, tmpWidth=%d, softbreak=%d, whitespace=%d",
435 // *advances, tmpWidth, itemAttrs->softBreak, itemAttrs->whiteSpace );
436 int glyph = logClusters[pos];
437 if ( lastGlyph != glyph ) {
438 while ( lastGlyph < glyph )
439 tmpItemWidth += advances[lastGlyph++];
440 if ( w + tmpWidth + tmpItemWidth > d->lineWidth ) {
441// qDebug("found break at w=%d, tmpWidth=%d, tmpItemWidth=%d", w, tmpWidth, tmpItemWidth);
442 d->widthUsed = w;
443 goto found;
444 }
445 }
446 if ( (itemAttrs->softBreak ||
447 ( breakany && itemAttrs->charStop ) ) &&
448 (i != d->firstItemInLine || pos != 0) ) {
449 if ( breakItem != i )
450 itemWidth = 0;
451 if (itemAttrs->softBreak)
452 breakany = FALSE;
453 breakItem = i;
454 breakPosition = pos;
455// qDebug("found possible break at item %d, position %d (absolute=%d), w=%d, tmpWidth=%d, tmpItemWidth=%d", breakItem, breakPosition, d->items[breakItem].position+breakPosition, w, tmpWidth, tmpItemWidth);
456 w += tmpWidth + tmpItemWidth;
457 itemWidth += tmpItemWidth;
458 tmpWidth = 0;
459 tmpItemWidth = 0;
460 }
461 itemAttrs++;
462 }
463 while ( lastGlyph < si->num_glyphs )
464 tmpItemWidth += advances[lastGlyph++];
465 tmpWidth += tmpItemWidth;
466 if ( w + tmpWidth > d->lineWidth ) {
467 d->widthUsed = w;
468 goto found;
469 }
470 }
471 }
472 }
473
474 found:
475 // no valid break point found
476 if ( breakPosition == -1 )
477 goto nobreak;
478
479// qDebug("linebreak at item %d, position %d, glyph %d wu=%d", breakItem, breakPosition, breakGlyph, d->widthUsed );
480 // split the line
481 if ( breakPosition > 0 ) {
482// int length = d->length( breakItem );
483
484// qDebug("splitting item, itemWidth=%d", itemWidth);
485 // not a full item, need to break
486 d->splitItem( breakItem, breakPosition );
487 d->currentItem = breakItem+1;
488 } else {
489 d->currentItem = breakItem;
490 }
491 }
492
493 result = Ok;
494
495 nobreak:
496 // position the objects in the line
497 available -= d->widthUsed;
498
499 numRuns = d->currentItem - d->firstItemInLine - numSpaceItems;
500 if ( numRuns > 127 ) {
501 levels = new Q_UINT8[numRuns];
502 visual = new int[numRuns];
503 }
504
505// qDebug("reordering %d runs, numSpaceItems=%d", numRuns, numSpaceItems );
506 for ( i = 0; i < numRuns; i++ ) {
507 levels[i] = d->items[i+d->firstItemInLine].analysis.bidiLevel;
508// qDebug(" level = %d", d->items[i+d->firstItemInLine].analysis.bidiLevel );
509 }
510 d->bidiReorder( numRuns, levels, visual );
511
512 end:
513 // ### FIXME
514 if ( alignment & Qt::AlignJustify ) {
515 // #### justify items
516 alignment = Qt::AlignAuto;
517 }
518 if ( (alignment & Qt::AlignHorizontal_Mask) == Qt::AlignAuto )
519 alignment = Qt::AlignLeft;
520 if ( alignment & Qt::AlignRight )
521 x += available;
522 else if ( alignment & Qt::AlignHCenter )
523 x += available/2;
524
525
526 int asc = ascent ? *ascent : 0;
527 int desc = descent ? *descent : 0;
528
529 for ( i = 0; i < numRuns; i++ ) {
530 QScriptItem &si = d->items[d->firstItemInLine+visual[i]];
531 asc = QMAX( asc, si.ascent );
532 desc = QMAX( desc, si.descent );
533 }
534
535 int left = x;
536 for ( i = 0; i < numRuns; i++ ) {
537 QScriptItem &si = d->items[d->firstItemInLine+visual[i]];
538// qDebug("positioning item %d with width %d (from=%d/length=%d) at %d", d->firstItemInLine+visual[i], si.width, si.position,
539// d->length(d->firstItemInLine+visual[i]), x );
540 si.x = x;
541 si.y = y + asc;
542 x += si.width;
543 }
544 int right = x;
545
546 if ( numSpaceItems ) {
547 if ( d->items[d->firstItemInLine+numRuns].analysis.bidiLevel % 2 ) {
548 x = left;
549 for ( i = 0; i < numSpaceItems; i++ ) {
550 QScriptItem &si = d->items[d->firstItemInLine + numRuns + i];
551 x -= si.width;
552 si.x = x;
553 si.y = y + asc;
554 }
555 } else {
556 for ( i = 0; i < numSpaceItems; i++ ) {
557 QScriptItem &si = d->items[d->firstItemInLine + numRuns + i];
558 si.x = x;
559 si.y = y + asc;
560 x += si.width;
561 }
562 }
563 }
564
565 if ( lineLeft )
566 *lineLeft = left;
567 if ( lineRight )
568 *lineRight = right;
569 if ( ascent )
570 *ascent = asc;
571 if ( descent )
572 *descent = desc;
573
574 if (levels != _levels)
575 delete []levels;
576 if (visual != _visual)
577 delete []visual;
578
579 return result;
580}
581
582void QTextLayout::endLayout()
583{
584 // nothing to do currently
585}
586
587
588int QTextLayout::nextCursorPosition( int oldPos, CursorMode mode ) const
589{
590// qDebug("looking for next cursor pos for %d", oldPos );
591 const QCharAttributes *attributes = d->attributes();
592 int len = d->string.length();
593 if ( oldPos >= len )
594 return oldPos;
595 oldPos++;
596 if ( mode == SkipCharacters ) {
597 while ( oldPos < len && !attributes[oldPos].charStop )
598 oldPos++;
599 } else {
600 while ( oldPos < len && !attributes[oldPos].wordStop && !attributes[oldPos-1].whiteSpace )
601 oldPos++;
602 }
603// qDebug(" -> %d", oldPos );
604 return oldPos;
605}
606
607int QTextLayout::previousCursorPosition( int oldPos, CursorMode mode ) const
608{
609// qDebug("looking for previous cursor pos for %d", oldPos );
610 const QCharAttributes *attributes = d->attributes();
611 if ( oldPos <= 0 )
612 return 0;
613 oldPos--;
614 if ( mode == SkipCharacters ) {
615 while ( oldPos && !attributes[oldPos].charStop )
616 oldPos--;
617 } else {
618 while ( oldPos && !attributes[oldPos].wordStop && !attributes[oldPos-1].whiteSpace )
619 oldPos--;
620 }
621// qDebug(" -> %d", oldPos );
622 return oldPos;
623}
624
625
626bool QTextLayout::validCursorPosition( int pos ) const
627{
628 const QCharAttributes *attributes = d->attributes();
629 if ( pos < 0 || pos > (int)d->string.length() )
630 return FALSE;
631 return attributes[pos].charStop;
632}
633
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