summaryrefslogtreecommitdiffstats
path: root/src/gui/text/qfontmetrics.cpp
blob: 5ad57b064b0c1fe8751b8492b4edf6b506a2ce74 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the QtGui module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 3 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL3 included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or (at your option) the GNU General
** Public license version 3 or any later version approved by the KDE Free
** Qt Foundation. The licenses are as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-2.0.html and
** https://www.gnu.org/licenses/gpl-3.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qfont.h"
#include "qpaintdevice.h"
#include "qfontmetrics.h"

#include "qfont_p.h"
#include "qfontengine_p.h"

QT_BEGIN_NAMESPACE


extern void qt_format_text(const QFont& font, const QRectF &_r,
                           int tf, const QString &text, QRectF *brect,
                           int tabStops, int *tabArray, int tabArrayLen,
                           QPainter *painter);

/*****************************************************************************
  QFontMetrics member functions
 *****************************************************************************/

/*!
    \class QFontMetrics
    \reentrant
    \inmodule QtGui

    \brief The QFontMetrics class provides font metrics information.

    \ingroup painting
    \ingroup shared

    QFontMetrics functions calculate the size of characters and
    strings for a given font. There are three ways you can create a
    QFontMetrics object:

    \list 1
    \li Calling the QFontMetrics constructor with a QFont creates a
    font metrics object for a screen-compatible font, i.e. the font
    cannot be a printer font. If the font is changed
    later, the font metrics object is \e not updated.

    (Note: If you use a printer font the values returned may be
    inaccurate. Printer fonts are not always accessible so the nearest
    screen font is used if a printer font is supplied.)

    \li QWidget::fontMetrics() returns the font metrics for a widget's
    font. This is equivalent to QFontMetrics(widget->font()). If the
    widget's font is changed later, the font metrics object is \e not
    updated.

    \li QPainter::fontMetrics() returns the font metrics for a
    painter's current font. If the painter's font is changed later, the
    font metrics object is \e not updated.
    \endlist

    Once created, the object provides functions to access the
    individual metrics of the font, its characters, and for strings
    rendered in the font.

    There are several functions that operate on the font: ascent(),
    descent(), height(), leading() and lineSpacing() return the basic
    size properties of the font. The underlinePos(), overlinePos(),
    strikeOutPos() and lineWidth() functions, return the properties of
    the line that underlines, overlines or strikes out the
    characters. These functions are all fast.

    There are also some functions that operate on the set of glyphs in
    the font: minLeftBearing(), minRightBearing() and maxWidth().
    These are by necessity slow, and we recommend avoiding them if
    possible.

    For each character, you can get its width(), leftBearing() and
    rightBearing() and find out whether it is in the font using
    inFont(). You can also treat the character as a string, and use
    the string functions on it.

    The string functions include width(), to return the width of a
    string in pixels (or points, for a printer), boundingRect(), to
    return a rectangle large enough to contain the rendered string,
    and size(), to return the size of that rectangle.

    Example:
    \snippet code/src_gui_text_qfontmetrics.cpp 0

    \sa QFont, QFontInfo, QFontDatabase, {Character Map Example}
*/

/*!
    \fn QRect QFontMetrics::boundingRect(int x, int y, int width, int height,
        int flags, const QString &text, int tabStops, int *tabArray) const
    \overload

    Returns the bounding rectangle for the given \a text within the
    rectangle specified by the \a x and \a y coordinates, \a width, and
    \a height.

    If Qt::TextExpandTabs is set in \a flags and \a tabArray is
    non-null, it specifies a 0-terminated sequence of pixel-positions
    for tabs; otherwise, if \a tabStops is non-zero, it is used as the
    tab spacing (in pixels).
*/

/*!
    Constructs a font metrics object for \a font.

    The font metrics will be compatible with the paintdevice used to
    create \a font.

    The font metrics object holds the information for the font that is
    passed in the constructor at the time it is created, and is not
    updated if the font's attributes are changed later.

    Use QFontMetrics(const QFont &, QPaintDevice *) to get the font
    metrics that are compatible with a certain paint device.
*/
QFontMetrics::QFontMetrics(const QFont &font)
    : d(font.d)
{
}

/*!
    Constructs a font metrics object for \a font and \a paintdevice.

    The font metrics will be compatible with the paintdevice passed.
    If the \a paintdevice is 0, the metrics will be screen-compatible,
    ie. the metrics you get if you use the font for drawing text on a
    \l{QWidget}{widgets} or \l{QPixmap}{pixmaps},
    not on a QPicture or QPrinter.

    The font metrics object holds the information for the font that is
    passed in the constructor at the time it is created, and is not
    updated if the font's attributes are changed later.
*/
QFontMetrics::QFontMetrics(const QFont &font, QPaintDevice *paintdevice)
{
    int dpi = paintdevice ? paintdevice->logicalDpiY() : qt_defaultDpi();
    const int screen = 0;
    if (font.d->dpi != dpi || font.d->screen != screen ) {
        d = new QFontPrivate(*font.d);
        d->dpi = dpi;
        d->screen = screen;
    } else {
        d = font.d;
    }

}

/*!
    Constructs a copy of \a fm.
*/
QFontMetrics::QFontMetrics(const QFontMetrics &fm)
    : d(fm.d)
{
}

/*!
    Destroys the font metrics object and frees all allocated
    resources.
*/
QFontMetrics::~QFontMetrics()
{
}

/*!
    Assigns the font metrics \a fm.
*/
QFontMetrics &QFontMetrics::operator=(const QFontMetrics &fm)
{
    d = fm.d;
    return *this;
}

/*!
    \fn QFontMetrics &QFontMetrics::operator=(QFontMetrics &&other)

    Move-assigns \a other to this QFontMetrics instance.

    \since 5.2
*/
/*!
    \fn QFontMetricsF &QFontMetricsF::operator=(QFontMetricsF &&other)

    Move-assigns \a other to this QFontMetricsF instance.
*/

/*!
    \fn void QFontMetrics::swap(QFontMetrics &other)
    \since 5.0

    Swaps this font metrics instance with \a other. This function is
    very fast and never fails.
*/

/*!
    Returns \c true if \a other is equal to this object; otherwise
    returns \c false.

    Two font metrics are considered equal if they were constructed
    from the same QFont and the paint devices they were constructed
    for are considered compatible.

    \sa operator!=()
*/
bool QFontMetrics::operator ==(const QFontMetrics &other) const
{
    return d == other.d;
}

/*!
    \fn bool QFontMetrics::operator !=(const QFontMetrics &other) const

    Returns \c true if \a other is not equal to this object; otherwise returns \c false.

    Two font metrics are considered equal if they were constructed
    from the same QFont and the paint devices they were constructed
    for are considered compatible.

    \sa operator==()
*/

/*!
    Returns the ascent of the font.

    The ascent of a font is the distance from the baseline to the
    highest position characters extend to. In practice, some font
    designers break this rule, e.g. when they put more than one accent
    on top of a character, or to accommodate an unusual character in
    an exotic language, so it is possible (though rare) that this
    value will be too small.

    \sa descent()
*/
int QFontMetrics::ascent() const
{
    QFontEngine *engine = d->engineForScript(QChar::Script_Common);
    Q_ASSERT(engine != 0);
    return qRound(engine->ascent());
}

/*!
    Returns the cap height of the font.

    \since 5.8

    The cap height of a font is the height of a capital letter above
    the baseline. It specifically is the height of capital letters
    that are flat - such as H or I - as opposed to round letters such
    as O, or pointed letters like A, both of which may display overshoot.

    \sa ascent()
*/
int QFontMetrics::capHeight() const
{
    QFontEngine *engine = d->engineForScript(QChar::Script_Common);
    Q_ASSERT(engine != 0);
    return qRound(engine->capHeight());
}

/*!
    Returns the descent of the font.

    The descent is the distance from the base line to the lowest point
    characters extend to. In practice, some font designers break this rule,
    e.g. to accommodate an unusual character in an exotic language, so
    it is possible (though rare) that this value will be too small.

    \sa ascent()
*/
int QFontMetrics::descent() const
{
    QFontEngine *engine = d->engineForScript(QChar::Script_Common);
    Q_ASSERT(engine != 0);
    return qRound(engine->descent());
}

/*!
    Returns the height of the font.

    This is always equal to ascent()+descent().

    \sa leading(), lineSpacing()
*/
int QFontMetrics::height() const
{
    QFontEngine *engine = d->engineForScript(QChar::Script_Common);
    Q_ASSERT(engine != 0);
    return qRound(engine->ascent()) + qRound(engine->descent());
}

/*!
    Returns the leading of the font.

    This is the natural inter-line spacing.

    \sa height(), lineSpacing()
*/
int QFontMetrics::leading() const
{
    QFontEngine *engine = d->engineForScript(QChar::Script_Common);
    Q_ASSERT(engine != 0);
    return qRound(engine->leading());
}

/*!
    Returns the distance from one base line to the next.

    This value is always equal to leading()+height().

    \sa height(), leading()
*/
int QFontMetrics::lineSpacing() const
{
    QFontEngine *engine = d->engineForScript(QChar::Script_Common);
    Q_ASSERT(engine != 0);
    return qRound(engine->leading()) + qRound(engine->ascent()) + qRound(engine->descent());
}

/*!
    Returns the minimum left bearing of the font.

    This is the smallest leftBearing(char) of all characters in the
    font.

    Note that this function can be very slow if the font is large.

    \sa minRightBearing(), leftBearing()
*/
int QFontMetrics::minLeftBearing() const
{
    QFontEngine *engine = d->engineForScript(QChar::Script_Common);
    Q_ASSERT(engine != 0);
    return qRound(engine->minLeftBearing());
}

/*!
    Returns the minimum right bearing of the font.

    This is the smallest rightBearing(char) of all characters in the
    font.

    Note that this function can be very slow if the font is large.

    \sa minLeftBearing(), rightBearing()
*/
int QFontMetrics::minRightBearing() const
{
    QFontEngine *engine = d->engineForScript(QChar::Script_Common);
    Q_ASSERT(engine != 0);
    return qRound(engine->minRightBearing());
}

/*!
    Returns the width of the widest character in the font.
*/
int QFontMetrics::maxWidth() const
{
    QFontEngine *engine = d->engineForScript(QChar::Script_Common);
    Q_ASSERT(engine != 0);
    return qRound(engine->maxCharWidth());
}

/*!
    Returns the 'x' height of the font. This is often but not always
    the same as the height of the character 'x'.
*/
int QFontMetrics::xHeight() const
{
    QFontEngine *engine = d->engineForScript(QChar::Script_Common);
    Q_ASSERT(engine != 0);
    if (d->capital == QFont::SmallCaps)
        return qRound(d->smallCapsFontPrivate()->engineForScript(QChar::Script_Common)->ascent());
    return qRound(engine->xHeight());
}

/*!
    \since 4.2

    Returns the average width of glyphs in the font.
*/
int QFontMetrics::averageCharWidth() const
{
    QFontEngine *engine = d->engineForScript(QChar::Script_Common);
    Q_ASSERT(engine != 0);
    return qRound(engine->averageCharWidth());
}

/*!
    Returns \c true if character \a ch is a valid character in the font;
    otherwise returns \c false.
*/
bool QFontMetrics::inFont(QChar ch) const
{
    return inFontUcs4(ch.unicode());
}

/*!
   Returns \c true if the character \a ucs4 encoded in UCS-4/UTF-32 is a valid
   character in the font; otherwise returns \c false.
*/
bool QFontMetrics::inFontUcs4(uint ucs4) const
{
    const int script = QChar::script(ucs4);
    QFontEngine *engine = d->engineForScript(script);
    Q_ASSERT(engine != 0);
    if (engine->type() == QFontEngine::Box)
        return false;
    return engine->canRender(ucs4);
}

/*!
    Returns the left bearing of character \a ch in the font.

    The left bearing is the right-ward distance of the left-most pixel
    of the character from the logical origin of the character. This
    value is negative if the pixels of the character extend to the
    left of the logical origin.

    See width(QChar) for a graphical description of this metric.

    \sa rightBearing(), minLeftBearing(), width()
*/
int QFontMetrics::leftBearing(QChar ch) const
{
    const int script = ch.script();
    QFontEngine *engine;
    if (d->capital == QFont::SmallCaps && ch.isLower())
        engine = d->smallCapsFontPrivate()->engineForScript(script);
    else
        engine = d->engineForScript(script);
    Q_ASSERT(engine != 0);
    if (engine->type() == QFontEngine::Box)
        return 0;

    d->alterCharForCapitalization(ch);

    glyph_t glyph = engine->glyphIndex(ch.unicode());

    qreal lb;
    engine->getGlyphBearings(glyph, &lb);
    return qRound(lb);
}

/*!
    Returns the right bearing of character \a ch in the font.

    The right bearing is the left-ward distance of the right-most
    pixel of the character from the logical origin of a subsequent
    character. This value is negative if the pixels of the character
    extend to the right of the width() of the character.

    See width() for a graphical description of this metric.

    \sa leftBearing(), minRightBearing(), width()
*/
int QFontMetrics::rightBearing(QChar ch) const
{
    const int script = ch.script();
    QFontEngine *engine;
    if (d->capital == QFont::SmallCaps && ch.isLower())
        engine = d->smallCapsFontPrivate()->engineForScript(script);
    else
        engine = d->engineForScript(script);
    Q_ASSERT(engine != 0);
    if (engine->type() == QFontEngine::Box)
        return 0;

    d->alterCharForCapitalization(ch);

    glyph_t glyph = engine->glyphIndex(ch.unicode());

    qreal rb;
    engine->getGlyphBearings(glyph, 0, &rb);
    return qRound(rb);
}

#if QT_DEPRECATED_SINCE(5, 11)
/*!
    Returns the width in pixels of the first \a len characters of \a
    text. If \a len is negative (the default), the entire string is
    used.

    Note that this value is \e not equal to boundingRect().width();
    boundingRect() returns a rectangle describing the pixels this
    string will cover whereas width() returns the distance to where
    the next string should be drawn.

    \deprecated in Qt 5.11. Use horizontalAdvance() instead.

    \sa boundingRect()
*/
int QFontMetrics::width(const QString &text, int len) const
{
    return horizontalAdvance(text, len);
}

/*!
    \internal
*/
int QFontMetrics::width(const QString &text, int len, int flags) const
{
#if QT_DEPRECATED_SINCE(5, 11) && QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
    if (flags & Qt::TextBypassShaping) {
        int pos = text.indexOf(QLatin1Char('\x9c'));
        if (pos != -1) {
            len = (len < 0) ? pos : qMin(pos, len);
        } else if (len < 0) {
            len = text.length();
        }
        if (len == 0)
            return 0;

        // Skip complex shaping, only use advances
        int numGlyphs = len;
        QVarLengthGlyphLayoutArray glyphs(numGlyphs);
        QFontEngine *engine = d->engineForScript(QChar::Script_Common);
        if (!engine->stringToCMap(text.data(), len, &glyphs, &numGlyphs, 0))
            Q_UNREACHABLE();

        QFixed width;
        for (int i = 0; i < numGlyphs; ++i)
            width += glyphs.advances[i];
        return qRound(width);
    }
#else
    Q_UNUSED(flags)
#endif

    return horizontalAdvance(text, len);
}

/*!
    \overload

    \image bearings.png Bearings

    Returns the logical width of character \a ch in pixels. This is a
    distance appropriate for drawing a subsequent character after \a
    ch.

    Some of the metrics are described in the image to the right. The
    central dark rectangles cover the logical width() of each
    character. The outer pale rectangles cover the leftBearing() and
    rightBearing() of each character. Notice that the bearings of "f"
    in this particular font are both negative, while the bearings of
    "o" are both positive.

    \deprecated in Qt 5.11. Use horizontalAdvance() instead.

    \warning This function will produce incorrect results for Arabic
    characters or non-spacing marks in the middle of a string, as the
    glyph shaping and positioning of marks that happens when
    processing strings cannot be taken into account. When implementing
    an interactive text control, use QTextLayout instead.

    \sa boundingRect()
*/
int QFontMetrics::width(QChar ch) const
{
    return horizontalAdvance(ch);
}
#endif // QT_DEPRECATED_SINCE(5, 11)

/*!
    Returns the horizontal advance in pixels of the first \a len characters of \a
    text. If \a len is negative (the default), the entire string is
    used.

    This is the distance appropriate for drawing a subsequent character
    after \a text.

    \since 5.11

    \sa boundingRect()
*/
int QFontMetrics::horizontalAdvance(const QString &text, int len) const
{
    int pos = text.indexOf(QLatin1Char('\x9c'));
    if (pos != -1) {
        len = (len < 0) ? pos : qMin(pos, len);
    } else if (len < 0) {
        len = text.length();
    }
    if (len == 0)
        return 0;

    QStackTextEngine layout(text, QFont(d.data()));
    return qRound(layout.width(0, len));
}

/*!
    \overload

    \image bearings.png Bearings

    Returns the horizontal advance of character \a ch in pixels. This is a
    distance appropriate for drawing a subsequent character after \a
    ch.

    Some of the metrics are described in the image. The
    central dark rectangles cover the logical horizontalAdvance() of each
    character. The outer pale rectangles cover the leftBearing() and
    rightBearing() of each character. Notice that the bearings of "f"
    in this particular font are both negative, while the bearings of
    "o" are both positive.

    \warning This function will produce incorrect results for Arabic
    characters or non-spacing marks in the middle of a string, as the
    glyph shaping and positioning of marks that happens when
    processing strings cannot be taken into account. When implementing
    an interactive text control, use QTextLayout instead.

    \since 5.11

    \sa boundingRect()
*/
int QFontMetrics::horizontalAdvance(QChar ch) const
{
    if (QChar::category(ch.unicode()) == QChar::Mark_NonSpacing)
        return 0;

    const int script = ch.script();
    QFontEngine *engine;
    if (d->capital == QFont::SmallCaps && ch.isLower())
        engine = d->smallCapsFontPrivate()->engineForScript(script);
    else
        engine = d->engineForScript(script);
    Q_ASSERT(engine != 0);

    d->alterCharForCapitalization(ch);

    glyph_t glyph = engine->glyphIndex(ch.unicode());
    QFixed advance;

    QGlyphLayout glyphs;
    glyphs.numGlyphs = 1;
    glyphs.glyphs = &glyph;
    glyphs.advances = &advance;
    engine->recalcAdvances(&glyphs, 0);

    return qRound(advance);
}

#if QT_VERSION < QT_VERSION_CHECK(6,0,0)
/*! \obsolete

    Returns the width of the character at position \a pos in the
    string \a text.

    The whole string is needed, as the glyph drawn may change
    depending on the context (the letter before and after the current
    one) for some languages (e.g. Arabic).

    This function also takes non spacing marks and ligatures into
    account.
*/
int QFontMetrics::charWidth(const QString &text, int pos) const
{
    int width = 0;
    if (pos < 0 || pos > (int)text.length())
        return width;

    QChar ch = text.at(pos);
    const int script = ch.script();
    if (script != QChar::Script_Common) {
        // complex script shaping. Have to do some hard work
        int from = qMax(0, pos - 8);
        int to = qMin(text.length(), pos + 8);
        QString cstr = QString::fromRawData(text.unicode() + from, to - from);
        QStackTextEngine layout(cstr, QFont(d.data()));
        layout.ignoreBidi = true;
        layout.itemize();
        width = qRound(layout.width(pos-from, 1));
    } else if (ch.category() != QChar::Mark_NonSpacing) {
        QFontEngine *engine;
        if (d->capital == QFont::SmallCaps && ch.isLower())
            engine = d->smallCapsFontPrivate()->engineForScript(script);
        else
            engine = d->engineForScript(script);
        Q_ASSERT(engine != 0);

        d->alterCharForCapitalization(ch);

        glyph_t glyph = engine->glyphIndex(ch.unicode());
        QFixed advance;

        QGlyphLayout glyphs;
        glyphs.numGlyphs = 1;
        glyphs.glyphs = &glyph;
        glyphs.advances = &advance;
        engine->recalcAdvances(&glyphs, 0);

        width = qRound(advance);
    }
    return width;
}
#endif

/*!
    Returns the bounding rectangle of the characters in the string
    specified by \a text. The bounding rectangle always covers at least
    the set of pixels the text would cover if drawn at (0, 0).

    Note that the bounding rectangle may extend to the left of (0, 0),
    e.g. for italicized fonts, and that the width of the returned
    rectangle might be different than what the width() method returns.

    If you want to know the advance width of the string (to lay out
    a set of strings next to each other), use horizontalAdvance() instead.

    Newline characters are processed as normal characters, \e not as
    linebreaks.

    The height of the bounding rectangle is at least as large as the
    value returned by height().

    \sa width(), height(), QPainter::boundingRect(), tightBoundingRect()
*/
QRect QFontMetrics::boundingRect(const QString &text) const
{
    if (text.length() == 0)
        return QRect();

    QStackTextEngine layout(text, QFont(d.data()));
    layout.itemize();
    glyph_metrics_t gm = layout.boundingBox(0, text.length());
    return QRect(qRound(gm.x), qRound(gm.y), qRound(gm.width), qRound(gm.height));
}

/*!
    Returns the rectangle that is covered by ink if character \a ch
    were to be drawn at the origin of the coordinate system.

    Note that the bounding rectangle may extend to the left of (0, 0)
    (e.g., for italicized fonts), and that the text output may cover \e
    all pixels in the bounding rectangle. For a space character the rectangle
    will usually be empty.

    Note that the rectangle usually extends both above and below the
    base line.

    \warning The width of the returned rectangle is not the advance width
    of the character. Use boundingRect(const QString &) or horizontalAdvance() instead.

    \sa width()
*/
QRect QFontMetrics::boundingRect(QChar ch) const
{
    const int script = ch.script();
    QFontEngine *engine;
    if (d->capital == QFont::SmallCaps && ch.isLower())
        engine = d->smallCapsFontPrivate()->engineForScript(script);
    else
        engine = d->engineForScript(script);
    Q_ASSERT(engine != 0);

    d->alterCharForCapitalization(ch);

    glyph_t glyph = engine->glyphIndex(ch.unicode());

    glyph_metrics_t gm = engine->boundingBox(glyph);
    return QRect(qRound(gm.x), qRound(gm.y), qRound(gm.width), qRound(gm.height));
}

/*!
    \overload

    Returns the bounding rectangle of the characters in the string
    specified by \a text, which is the set of pixels the text would
    cover if drawn at (0, 0). The drawing, and hence the bounding
    rectangle, is constrained to the rectangle \a rect.

    The \a flags argument is the bitwise OR of the following flags:
    \list
    \li Qt::AlignLeft aligns to the left border, except for
          Arabic and Hebrew where it aligns to the right.
    \li Qt::AlignRight aligns to the right border, except for
          Arabic and Hebrew where it aligns to the left.
    \li Qt::AlignJustify produces justified text.
    \li Qt::AlignHCenter aligns horizontally centered.
    \li Qt::AlignTop aligns to the top border.
    \li Qt::AlignBottom aligns to the bottom border.
    \li Qt::AlignVCenter aligns vertically centered
    \li Qt::AlignCenter (== \c{Qt::AlignHCenter | Qt::AlignVCenter})
    \li Qt::TextSingleLine ignores newline characters in the text.
    \li Qt::TextExpandTabs expands tabs (see below)
    \li Qt::TextShowMnemonic interprets "&x" as \underline{x}; i.e., underlined.
    \li Qt::TextWordWrap breaks the text to fit the rectangle.
    \endlist

    Qt::Horizontal alignment defaults to Qt::AlignLeft and vertical
    alignment defaults to Qt::AlignTop.

    If several of the horizontal or several of the vertical alignment
    flags are set, the resulting alignment is undefined.

    If Qt::TextExpandTabs is set in \a flags, then: if \a tabArray is
    non-null, it specifies a 0-terminated sequence of pixel-positions
    for tabs; otherwise if \a tabStops is non-zero, it is used as the
    tab spacing (in pixels).

    Note that the bounding rectangle may extend to the left of (0, 0),
    e.g. for italicized fonts, and that the text output may cover \e
    all pixels in the bounding rectangle.

    Newline characters are processed as linebreaks.

    Despite the different actual character heights, the heights of the
    bounding rectangles of "Yes" and "yes" are the same.

    The bounding rectangle returned by this function is somewhat larger
    than that calculated by the simpler boundingRect() function. This
    function uses the \l{minLeftBearing()}{maximum left} and
    \l{minRightBearing()}{right} font bearings as is
    necessary for multi-line text to align correctly. Also,
    fontHeight() and lineSpacing() are used to calculate the height,
    rather than individual character heights.

    \sa width(), QPainter::boundingRect(), Qt::Alignment
*/
QRect QFontMetrics::boundingRect(const QRect &rect, int flags, const QString &text, int tabStops,
                                 int *tabArray) const
{
    int tabArrayLen = 0;
    if (tabArray)
        while (tabArray[tabArrayLen])
            tabArrayLen++;

    QRectF rb;
    QRectF rr(rect);
    qt_format_text(QFont(d.data()), rr, flags | Qt::TextDontPrint, text, &rb, tabStops, tabArray,
                   tabArrayLen, 0);

    return rb.toAlignedRect();
}

/*!
    Returns the size in pixels of \a text.

    The \a flags argument is the bitwise OR of the following flags:
    \list
    \li Qt::TextSingleLine ignores newline characters.
    \li Qt::TextExpandTabs expands tabs (see below)
    \li Qt::TextShowMnemonic interprets "&x" as \underline{x}; i.e., underlined.
    \li Qt::TextWordWrap breaks the text to fit the rectangle.
    \endlist

    If Qt::TextExpandTabs is set in \a flags, then: if \a tabArray is
    non-null, it specifies a 0-terminated sequence of pixel-positions
    for tabs; otherwise if \a tabStops is non-zero, it is used as the
    tab spacing (in pixels).

    Newline characters are processed as linebreaks.

    Despite the different actual character heights, the heights of the
    bounding rectangles of "Yes" and "yes" are the same.

    \sa boundingRect()
*/
QSize QFontMetrics::size(int flags, const QString &text, int tabStops, int *tabArray) const
{
    return boundingRect(QRect(0,0,0,0), flags | Qt::TextLongestVariant, text, tabStops, tabArray).size();
}

/*!
  \since 4.3

    Returns a tight bounding rectangle around the characters in the
    string specified by \a text. The bounding rectangle always covers
    at least the set of pixels the text would cover if drawn at (0,
    0).

    Note that the bounding rectangle may extend to the left of (0, 0),
    e.g. for italicized fonts, and that the width of the returned
    rectangle might be different than what the width() method returns.

    If you want to know the advance width of the string (to lay out
    a set of strings next to each other), use horizontalAdvance() instead.

    Newline characters are processed as normal characters, \e not as
    linebreaks.

    \warning Calling this method is very slow on Windows.

    \sa width(), height(), boundingRect()
*/
QRect QFontMetrics::tightBoundingRect(const QString &text) const
{
    if (text.length() == 0)
        return QRect();

    QStackTextEngine layout(text, QFont(d.data()));
    layout.itemize();
    glyph_metrics_t gm = layout.tightBoundingBox(0, text.length());
    return QRect(qRound(gm.x), qRound(gm.y), qRound(gm.width), qRound(gm.height));
}


/*!
    \since 4.2

    If the string \a text is wider than \a width, returns an elided
    version of the string (i.e., a string with "..." in it).
    Otherwise, returns the original string.

    The \a mode parameter specifies whether the text is elided on the
    left (e.g., "...tech"), in the middle (e.g., "Tr...ch"), or on
    the right (e.g., "Trol...").

    The \a width is specified in pixels, not characters.

    The \a flags argument is optional and currently only supports
    Qt::TextShowMnemonic as value.

    The elide mark follows the \l{Qt::LayoutDirection}{layoutdirection}.
    For example, it will be on the right side of the text for right-to-left
    layouts if the \a mode is \c{Qt::ElideLeft}, and on the left side of the
    text if the \a mode is \c{Qt::ElideRight}.

*/
QString QFontMetrics::elidedText(const QString &text, Qt::TextElideMode mode, int width, int flags) const
{
    QString _text = text;
    if (!(flags & Qt::TextLongestVariant)) {
        int posA = 0;
        int posB = _text.indexOf(QLatin1Char('\x9c'));
        while (posB >= 0) {
            QString portion = _text.mid(posA, posB - posA);
            if (size(flags, portion).width() <= width)
                return portion;
            posA = posB + 1;
            posB = _text.indexOf(QLatin1Char('\x9c'), posA);
        }
        _text = _text.mid(posA);
    }
    QStackTextEngine engine(_text, QFont(d.data()));
    return engine.elidedText(mode, width, flags);
}

/*!
    Returns the distance from the base line to where an underscore
    should be drawn.

    \sa overlinePos(), strikeOutPos(), lineWidth()
*/
int QFontMetrics::underlinePos() const
{
    QFontEngine *engine = d->engineForScript(QChar::Script_Common);
    Q_ASSERT(engine != 0);
    return qRound(engine->underlinePosition());
}

/*!
    Returns the distance from the base line to where an overline
    should be drawn.

    \sa underlinePos(), strikeOutPos(), lineWidth()
*/
int QFontMetrics::overlinePos() const
{
    return ascent() + 1;
}

/*!
    Returns the distance from the base line to where the strikeout
    line should be drawn.

    \sa underlinePos(), overlinePos(), lineWidth()
*/
int QFontMetrics::strikeOutPos() const
{
    int pos = ascent() / 3;
    return pos > 0 ? pos : 1;
}

/*!
    Returns the width of the underline and strikeout lines, adjusted
    for the point size of the font.

    \sa underlinePos(), overlinePos(), strikeOutPos()
*/
int QFontMetrics::lineWidth() const
{
    QFontEngine *engine = d->engineForScript(QChar::Script_Common);
    Q_ASSERT(engine != 0);
    return qRound(engine->lineThickness());
}




/*****************************************************************************
  QFontMetricsF member functions
 *****************************************************************************/

/*!
    \class QFontMetricsF
    \reentrant
    \inmodule QtGui

    \brief The QFontMetricsF class provides font metrics information.

    \ingroup painting
    \ingroup shared

    QFontMetricsF functions calculate the size of characters and
    strings for a given font. You can construct a QFontMetricsF object
    with an existing QFont to obtain metrics for that font. If the
    font is changed later, the font metrics object is \e not updated.

    Once created, the object provides functions to access the
    individual metrics of the font, its characters, and for strings
    rendered in the font.

    There are several functions that operate on the font: ascent(),
    descent(), height(), leading() and lineSpacing() return the basic
    size properties of the font. The underlinePos(), overlinePos(),
    strikeOutPos() and lineWidth() functions, return the properties of
    the line that underlines, overlines or strikes out the
    characters. These functions are all fast.

    There are also some functions that operate on the set of glyphs in
    the font: minLeftBearing(), minRightBearing() and maxWidth().
    These are by necessity slow, and we recommend avoiding them if
    possible.

    For each character, you can get its width(), leftBearing() and
    rightBearing() and find out whether it is in the font using
    inFont(). You can also treat the character as a string, and use
    the string functions on it.

    The string functions include width(), to return the width of a
    string in pixels (or points, for a printer), boundingRect(), to
    return a rectangle large enough to contain the rendered string,
    and size(), to return the size of that rectangle.

    Example:
    \snippet code/src_gui_text_qfontmetrics.cpp 1

    \sa QFont, QFontInfo, QFontDatabase
*/

/*!
    \since 4.2

    Constructs a font metrics object with floating point precision
    from the given \a fontMetrics object.
*/
QFontMetricsF::QFontMetricsF(const QFontMetrics &fontMetrics)
    : d(fontMetrics.d)
{
}

/*!
    \since 4.2

    Assigns \a other to this object.
*/
QFontMetricsF &QFontMetricsF::operator=(const QFontMetrics &other)
{
    d = other.d;
    return *this;
}

/*!
    \fn void QFontMetricsF::swap(QFontMetricsF &other)
    \since 5.0

    Swaps this font metrics instance with \a other. This function is
    very fast and never fails.
*/



/*!
    Constructs a font metrics object for \a font.

    The font metrics will be compatible with the paintdevice used to
    create \a font.

    The font metrics object holds the information for the font that is
    passed in the constructor at the time it is created, and is not
    updated if the font's attributes are changed later.

    Use QFontMetricsF(const QFont &, QPaintDevice *) to get the font
    metrics that are compatible with a certain paint device.
*/
QFontMetricsF::QFontMetricsF(const QFont &font)
    : d(font.d)
{
}

/*!
    Constructs a font metrics object for \a font and \a paintdevice.

    The font metrics will be compatible with the paintdevice passed.
    If the \a paintdevice is 0, the metrics will be screen-compatible,
    ie. the metrics you get if you use the font for drawing text on a
    \l{QWidget}{widgets} or \l{QPixmap}{pixmaps},
    not on a QPicture or QPrinter.

    The font metrics object holds the information for the font that is
    passed in the constructor at the time it is created, and is not
    updated if the font's attributes are changed later.
*/
QFontMetricsF::QFontMetricsF(const QFont &font, QPaintDevice *paintdevice)
{
    int dpi = paintdevice ? paintdevice->logicalDpiY() : qt_defaultDpi();
    const int screen = 0;
    if (font.d->dpi != dpi || font.d->screen != screen ) {
        d = new QFontPrivate(*font.d);
        d->dpi = dpi;
        d->screen = screen;
    } else {
        d = font.d;
    }

}

/*!
    Constructs a copy of \a fm.
*/
QFontMetricsF::QFontMetricsF(const QFontMetricsF &fm)
    : d(fm.d)
{
}

/*!
    Destroys the font metrics object and frees all allocated
    resources.
*/
QFontMetricsF::~QFontMetricsF()
{
}

/*!
    Assigns the font metrics \a fm to this font metrics object.
*/
QFontMetricsF &QFontMetricsF::operator=(const QFontMetricsF &fm)
{
    d = fm.d;
    return *this;
}

/*!
  Returns \c true if the font metrics are equal to the \a other font
  metrics; otherwise returns \c false.

  Two font metrics are considered equal if they were constructed from the
  same QFont and the paint devices they were constructed for are
  considered to be compatible.
*/
bool QFontMetricsF::operator ==(const QFontMetricsF &other) const
{
    return d == other.d;
}

/*!
    \fn bool QFontMetricsF::operator !=(const QFontMetricsF &other) const
    \overload

    Returns \c true if the font metrics are not equal to the \a other font
    metrics; otherwise returns \c false.

    \sa operator==()
*/

/*!
    Returns the ascent of the font.

    The ascent of a font is the distance from the baseline to the
    highest position characters extend to. In practice, some font
    designers break this rule, e.g. when they put more than one accent
    on top of a character, or to accommodate an unusual character in
    an exotic language, so it is possible (though rare) that this
    value will be too small.

    \sa descent()
*/
qreal QFontMetricsF::ascent() const
{
    QFontEngine *engine = d->engineForScript(QChar::Script_Common);
    Q_ASSERT(engine != 0);
    return engine->ascent().toReal();
}

/*!
    Returns the cap height of the font.

    \since 5.8

    The cap height of a font is the height of a capital letter above
    the baseline. It specifically is the height of capital letters
    that are flat - such as H or I - as opposed to round letters such
    as O, or pointed letters like A, both of which may display overshoot.

    \sa ascent()
*/
qreal QFontMetricsF::capHeight() const
{
    QFontEngine *engine = d->engineForScript(QChar::Script_Common);
    Q_ASSERT(engine != 0);
    return engine->capHeight().toReal();
}

/*!
    Returns the descent of the font.

    The descent is the distance from the base line to the lowest point
    characters extend to. (Note that this is different from X, which
    adds 1 pixel.) In practice, some font designers break this rule,
    e.g. to accommodate an unusual character in an exotic language, so
    it is possible (though rare) that this value will be too small.

    \sa ascent()
*/
qreal QFontMetricsF::descent() const
{
    QFontEngine *engine = d->engineForScript(QChar::Script_Common);
    Q_ASSERT(engine != 0);
    return engine->descent().toReal();
}

/*!
    Returns the height of the font.

    This is always equal to ascent()+descent().

    \sa leading(), lineSpacing()
*/
qreal QFontMetricsF::height() const
{
    QFontEngine *engine = d->engineForScript(QChar::Script_Common);
    Q_ASSERT(engine != 0);

    return (engine->ascent() + engine->descent()).toReal();
}

/*!
    Returns the leading of the font.

    This is the natural inter-line spacing.

    \sa height(), lineSpacing()
*/
qreal QFontMetricsF::leading() const
{
    QFontEngine *engine = d->engineForScript(QChar::Script_Common);
    Q_ASSERT(engine != 0);
    return engine->leading().toReal();
}

/*!
    Returns the distance from one base line to the next.

    This value is always equal to leading()+height().

    \sa height(), leading()
*/
qreal QFontMetricsF::lineSpacing() const
{
    QFontEngine *engine = d->engineForScript(QChar::Script_Common);
    Q_ASSERT(engine != 0);
    return (engine->leading() + engine->ascent() + engine->descent()).toReal();
}

/*!
    Returns the minimum left bearing of the font.

    This is the smallest leftBearing(char) of all characters in the
    font.

    Note that this function can be very slow if the font is large.

    \sa minRightBearing(), leftBearing()
*/
qreal QFontMetricsF::minLeftBearing() const
{
    QFontEngine *engine = d->engineForScript(QChar::Script_Common);
    Q_ASSERT(engine != 0);
    return engine->minLeftBearing();
}

/*!
    Returns the minimum right bearing of the font.

    This is the smallest rightBearing(char) of all characters in the
    font.

    Note that this function can be very slow if the font is large.

    \sa minLeftBearing(), rightBearing()
*/
qreal QFontMetricsF::minRightBearing() const
{
    QFontEngine *engine = d->engineForScript(QChar::Script_Common);
    Q_ASSERT(engine != 0);
    return engine->minRightBearing();
}

/*!
    Returns the width of the widest character in the font.
*/
qreal QFontMetricsF::maxWidth() const
{
    QFontEngine *engine = d->engineForScript(QChar::Script_Common);
    Q_ASSERT(engine != 0);
    return engine->maxCharWidth();
}

/*!
    Returns the 'x' height of the font. This is often but not always
    the same as the height of the character 'x'.
*/
qreal QFontMetricsF::xHeight() const
{
    QFontEngine *engine = d->engineForScript(QChar::Script_Common);
    Q_ASSERT(engine != 0);
    if (d->capital == QFont::SmallCaps)
        return d->smallCapsFontPrivate()->engineForScript(QChar::Script_Common)->ascent().toReal();
    return engine->xHeight().toReal();
}

/*!
    \since 4.2

    Returns the average width of glyphs in the font.
*/
qreal QFontMetricsF::averageCharWidth() const
{
    QFontEngine *engine = d->engineForScript(QChar::Script_Common);
    Q_ASSERT(engine != 0);
    return engine->averageCharWidth().toReal();
}

/*!
    Returns \c true if character \a ch is a valid character in the font;
    otherwise returns \c false.
*/
bool QFontMetricsF::inFont(QChar ch) const
{
    return inFontUcs4(ch.unicode());
}

/*!
    \fn bool QFontMetricsF::inFontUcs4(uint ch) const

    Returns \c true if the character given by \a ch, encoded in UCS-4/UTF-32,
    is a valid character in the font; otherwise returns \c false.
*/
bool QFontMetricsF::inFontUcs4(uint ucs4) const
{
    const int script = QChar::script(ucs4);
    QFontEngine *engine = d->engineForScript(script);
    Q_ASSERT(engine != 0);
    if (engine->type() == QFontEngine::Box)
        return false;
    return engine->canRender(ucs4);
}

/*!
    Returns the left bearing of character \a ch in the font.

    The left bearing is the right-ward distance of the left-most pixel
    of the character from the logical origin of the character. This
    value is negative if the pixels of the character extend to the
    left of the logical origin.

    See width(QChar) for a graphical description of this metric.

    \sa rightBearing(), minLeftBearing(), width()
*/
qreal QFontMetricsF::leftBearing(QChar ch) const
{
    const int script = ch.script();
    QFontEngine *engine;
    if (d->capital == QFont::SmallCaps && ch.isLower())
        engine = d->smallCapsFontPrivate()->engineForScript(script);
    else
        engine = d->engineForScript(script);
    Q_ASSERT(engine != 0);
    if (engine->type() == QFontEngine::Box)
        return 0;

    d->alterCharForCapitalization(ch);

    glyph_t glyph = engine->glyphIndex(ch.unicode());

    qreal lb;
    engine->getGlyphBearings(glyph, &lb);
    return lb;
}

/*!
    Returns the right bearing of character \a ch in the font.

    The right bearing is the left-ward distance of the right-most
    pixel of the character from the logical origin of a subsequent
    character. This value is negative if the pixels of the character
    extend to the right of the width() of the character.

    See width() for a graphical description of this metric.

    \sa leftBearing(), minRightBearing(), width()
*/
qreal QFontMetricsF::rightBearing(QChar ch) const
{
    const int script = ch.script();
    QFontEngine *engine;
    if (d->capital == QFont::SmallCaps && ch.isLower())
        engine = d->smallCapsFontPrivate()->engineForScript(script);
    else
        engine = d->engineForScript(script);
    Q_ASSERT(engine != 0);
    if (engine->type() == QFontEngine::Box)
        return 0;

    d->alterCharForCapitalization(ch);

    glyph_t glyph = engine->glyphIndex(ch.unicode());

    qreal rb;
    engine->getGlyphBearings(glyph, 0, &rb);
    return rb;

}

#if QT_DEPRECATED_SINCE(5, 11)
/*!
    Returns the width in pixels of the characters in the given \a text.

    Note that this value is \e not equal to the width returned by
    boundingRect().width() because boundingRect() returns a rectangle
    describing the pixels this string will cover whereas width()
    returns the distance to where the next string should be drawn.

    \deprecated in Qt 5.11. Use horizontalAdvance() instead.

    \sa boundingRect()
*/
qreal QFontMetricsF::width(const QString &text) const
{
    return horizontalAdvance(text);
}

/*!
    \overload

    \image bearings.png Bearings

    Returns the logical width of character \a ch in pixels. This is a
    distance appropriate for drawing a subsequent character after \a
    ch.

    Some of the metrics are described in the image to the right. The
    central dark rectangles cover the logical width() of each
    character. The outer pale rectangles cover the leftBearing() and
    rightBearing() of each character. Notice that the bearings of "f"
    in this particular font are both negative, while the bearings of
    "o" are both positive.

    \deprecated in Qt 5.11. Use horizontalAdvance() instead.

    \warning This function will produce incorrect results for Arabic
    characters or non-spacing marks in the middle of a string, as the
    glyph shaping and positioning of marks that happens when
    processing strings cannot be taken into account. When implementing
    an interactive text control, use QTextLayout instead.

    \sa boundingRect()
*/
qreal QFontMetricsF::width(QChar ch) const
{
    return horizontalAdvance(ch);
}
#endif

/*!
    Returns the horizontal advance in pixels of the first \a length characters of \a
    text. If \a length is negative (the default), the entire string is
    used.

    The advance is the distance appropriate for drawing a subsequent
    character after \a text.

    \since 5.11

    \sa boundingRect()
*/
qreal QFontMetricsF::horizontalAdvance(const QString &text, int length) const
{
    int pos = text.indexOf(QLatin1Char('\x9c'));
    if (pos != -1)
        length = (length < 0) ? pos : qMin(pos, length);
    else if (length < 0)
        length = text.length();

    if (length == 0)
        return 0;

    QStackTextEngine layout(text, QFont(d.data()));
    layout.itemize();
    return layout.width(0, length).toReal();
}

/*!
    \overload

    \image bearings.png Bearings

    Returns the horizontal advance of character \a ch in pixels. This is a
    distance appropriate for drawing a subsequent character after \a
    ch.

    Some of the metrics are described in the image to the right. The
    central dark rectangles cover the logical width() of each
    character. The outer pale rectangles cover the leftBearing() and
    rightBearing() of each character. Notice that the bearings of "f"
    in this particular font are both negative, while the bearings of
    "o" are both positive.

    \warning This function will produce incorrect results for Arabic
    characters or non-spacing marks in the middle of a string, as the
    glyph shaping and positioning of marks that happens when
    processing strings cannot be taken into account. When implementing
    an interactive text control, use QTextLayout instead.

    \since 5.11

    \sa boundingRect()
*/
qreal QFontMetricsF::horizontalAdvance(QChar ch) const
{
    if (ch.category() == QChar::Mark_NonSpacing)
        return 0.;

    const int script = ch.script();
    QFontEngine *engine;
    if (d->capital == QFont::SmallCaps && ch.isLower())
        engine = d->smallCapsFontPrivate()->engineForScript(script);
    else
        engine = d->engineForScript(script);
    Q_ASSERT(engine != 0);

    d->alterCharForCapitalization(ch);

    glyph_t glyph = engine->glyphIndex(ch.unicode());
    QFixed advance;

    QGlyphLayout glyphs;
    glyphs.numGlyphs = 1;
    glyphs.glyphs = &glyph;
    glyphs.advances = &advance;
    engine->recalcAdvances(&glyphs, 0);

    return advance.toReal();
}


/*!
    Returns the bounding rectangle of the characters in the string
    specified by \a text. The bounding rectangle always covers at least
    the set of pixels the text would cover if drawn at (0, 0).

    Note that the bounding rectangle may extend to the left of (0, 0),
    e.g. for italicized fonts, and that the width of the returned
    rectangle might be different than what the width() method returns.

    If you want to know the advance width of the string (to lay out
    a set of strings next to each other), use horizontalAdvance() instead.

    Newline characters are processed as normal characters, \e not as
    linebreaks.

    The height of the bounding rectangle is at least as large as the
    value returned height().

    \sa width(), height(), QPainter::boundingRect()
*/
QRectF QFontMetricsF::boundingRect(const QString &text) const
{
    int len = text.length();
    if (len == 0)
        return QRectF();

    QStackTextEngine layout(text, QFont(d.data()));
    layout.itemize();
    glyph_metrics_t gm = layout.boundingBox(0, len);
    return QRectF(gm.x.toReal(), gm.y.toReal(),
                  gm.width.toReal(), gm.height.toReal());
}

/*!
    Returns the bounding rectangle of the character \a ch relative to
    the left-most point on the base line.

    Note that the bounding rectangle may extend to the left of (0, 0),
    e.g. for italicized fonts, and that the text output may cover \e
    all pixels in the bounding rectangle.

    Note that the rectangle usually extends both above and below the
    base line.

    \sa width()
*/
QRectF QFontMetricsF::boundingRect(QChar ch) const
{
    const int script = ch.script();
    QFontEngine *engine;
    if (d->capital == QFont::SmallCaps && ch.isLower())
        engine = d->smallCapsFontPrivate()->engineForScript(script);
    else
        engine = d->engineForScript(script);
    Q_ASSERT(engine != 0);

    d->alterCharForCapitalization(ch);

    glyph_t glyph = engine->glyphIndex(ch.unicode());

    glyph_metrics_t gm = engine->boundingBox(glyph);
    return QRectF(gm.x.toReal(), gm.y.toReal(), gm.width.toReal(), gm.height.toReal());
}

/*!
    \overload

    Returns the bounding rectangle of the characters in the given \a text.
    This is the set of pixels the text would cover if drawn when constrained
    to the bounding rectangle specified by \a rect.

    The \a flags argument is the bitwise OR of the following flags:
    \list
    \li Qt::AlignLeft aligns to the left border, except for
          Arabic and Hebrew where it aligns to the right.
    \li Qt::AlignRight aligns to the right border, except for
          Arabic and Hebrew where it aligns to the left.
    \li Qt::AlignJustify produces justified text.
    \li Qt::AlignHCenter aligns horizontally centered.
    \li Qt::AlignTop aligns to the top border.
    \li Qt::AlignBottom aligns to the bottom border.
    \li Qt::AlignVCenter aligns vertically centered
    \li Qt::AlignCenter (== \c{Qt::AlignHCenter | Qt::AlignVCenter})
    \li Qt::TextSingleLine ignores newline characters in the text.
    \li Qt::TextExpandTabs expands tabs (see below)
    \li Qt::TextShowMnemonic interprets "&x" as \underline{x}; i.e., underlined.
    \li Qt::TextWordWrap breaks the text to fit the rectangle.
    \endlist

    Qt::Horizontal alignment defaults to Qt::AlignLeft and vertical
    alignment defaults to Qt::AlignTop.

    If several of the horizontal or several of the vertical alignment
    flags are set, the resulting alignment is undefined.

    These flags are defined in \l{Qt::AlignmentFlag}.

    If Qt::TextExpandTabs is set in \a flags, the following behavior is
    used to interpret tab characters in the text:
    \list
    \li If \a tabArray is non-null, it specifies a 0-terminated sequence of
       pixel-positions for tabs in the text.
    \li If \a tabStops is non-zero, it is used as the tab spacing (in pixels).
    \endlist

    Note that the bounding rectangle may extend to the left of (0, 0),
    e.g. for italicized fonts.

    Newline characters are processed as line breaks.

    Despite the different actual character heights, the heights of the
    bounding rectangles of "Yes" and "yes" are the same.

    The bounding rectangle returned by this function is somewhat larger
    than that calculated by the simpler boundingRect() function. This
    function uses the \l{minLeftBearing()}{maximum left} and
    \l{minRightBearing()}{right} font bearings as is
    necessary for multi-line text to align correctly. Also,
    fontHeight() and lineSpacing() are used to calculate the height,
    rather than individual character heights.

    \sa width(), QPainter::boundingRect(), Qt::Alignment
*/
QRectF QFontMetricsF::boundingRect(const QRectF &rect, int flags, const QString& text,
                                   int tabStops, int *tabArray) const
{
    int tabArrayLen = 0;
    if (tabArray)
        while (tabArray[tabArrayLen])
            tabArrayLen++;

    QRectF rb;
    qt_format_text(QFont(d.data()), rect, flags | Qt::TextDontPrint, text, &rb, tabStops, tabArray,
                   tabArrayLen, 0);
    return rb;
}

/*!
    Returns the size in pixels of the characters in the given \a text.

    The \a flags argument is the bitwise OR of the following flags:
    \list
    \li Qt::TextSingleLine ignores newline characters.
    \li Qt::TextExpandTabs expands tabs (see below)
    \li Qt::TextShowMnemonic interprets "&x" as \underline{x}; i.e., underlined.
    \li Qt::TextWordWrap breaks the text to fit the rectangle.
    \endlist

    These flags are defined in the \l{Qt::TextFlag} enum.

    If Qt::TextExpandTabs is set in \a flags, the following behavior is
    used to interpret tab characters in the text:
    \list
    \li If \a tabArray is non-null, it specifies a 0-terminated sequence of
       pixel-positions for tabs in the text.
    \li If \a tabStops is non-zero, it is used as the tab spacing (in pixels).
    \endlist

    Newline characters are processed as line breaks.

    Note: Despite the different actual character heights, the heights of the
    bounding rectangles of "Yes" and "yes" are the same.

    \sa boundingRect()
*/
QSizeF QFontMetricsF::size(int flags, const QString &text, int tabStops, int *tabArray) const
{
    return boundingRect(QRectF(), flags | Qt::TextLongestVariant, text, tabStops, tabArray).size();
}

/*!
  \since 4.3

    Returns a tight bounding rectangle around the characters in the
    string specified by \a text. The bounding rectangle always covers
    at least the set of pixels the text would cover if drawn at (0,
    0).

    Note that the bounding rectangle may extend to the left of (0, 0),
    e.g. for italicized fonts, and that the width of the returned
    rectangle might be different than what the width() method returns.

    If you want to know the advance width of the string (to lay out
    a set of strings next to each other), use horizontalAdvance() instead.

    Newline characters are processed as normal characters, \e not as
    linebreaks.

    \warning Calling this method is very slow on Windows.

    \sa width(), height(), boundingRect()
*/
QRectF QFontMetricsF::tightBoundingRect(const QString &text) const
{
    if (text.length() == 0)
        return QRect();

    QStackTextEngine layout(text, QFont(d.data()));
    layout.itemize();
    glyph_metrics_t gm = layout.tightBoundingBox(0, text.length());
    return QRectF(gm.x.toReal(), gm.y.toReal(), gm.width.toReal(), gm.height.toReal());
}

/*!
    \since 4.2

    If the string \a text is wider than \a width, returns an elided
    version of the string (i.e., a string with "..." in it).
    Otherwise, returns the original string.

    The \a mode parameter specifies whether the text is elided on the
    left (for example, "...tech"), in the middle (for example, "Tr...ch"), or
    on the right (for example, "Trol...").

    The \a width is specified in pixels, not characters.

    The \a flags argument is optional and currently only supports
    Qt::TextShowMnemonic as value.

    The elide mark follows the \l{Qt::LayoutDirection}{layoutdirection}.
    For example, it will be on the right side of the text for right-to-left
    layouts if the \a mode is \c{Qt::ElideLeft}, and on the left side of the
    text if the \a mode is \c{Qt::ElideRight}.
*/
QString QFontMetricsF::elidedText(const QString &text, Qt::TextElideMode mode, qreal width, int flags) const
{
    QString _text = text;
    if (!(flags & Qt::TextLongestVariant)) {
        int posA = 0;
        int posB = _text.indexOf(QLatin1Char('\x9c'));
        while (posB >= 0) {
            QString portion = _text.mid(posA, posB - posA);
            if (size(flags, portion).width() <= width)
                return portion;
            posA = posB + 1;
            posB = _text.indexOf(QLatin1Char('\x9c'), posA);
        }
        _text = _text.mid(posA);
    }
    QStackTextEngine engine(_text, QFont(d.data()));
    return engine.elidedText(mode, QFixed::fromReal(width), flags);
}

/*!
    Returns the distance from the base line to where an underscore
    should be drawn.

    \sa overlinePos(), strikeOutPos(), lineWidth()
*/
qreal QFontMetricsF::underlinePos() const
{
    QFontEngine *engine = d->engineForScript(QChar::Script_Common);
    Q_ASSERT(engine != 0);
    return engine->underlinePosition().toReal();
}

/*!
    Returns the distance from the base line to where an overline
    should be drawn.

    \sa underlinePos(), strikeOutPos(), lineWidth()
*/
qreal QFontMetricsF::overlinePos() const
{
    return ascent() + 1;
}

/*!
    Returns the distance from the base line to where the strikeout
    line should be drawn.

    \sa underlinePos(), overlinePos(), lineWidth()
*/
qreal QFontMetricsF::strikeOutPos() const
{
    return ascent() / 3.;
}

/*!
    Returns the width of the underline and strikeout lines, adjusted
    for the point size of the font.

    \sa underlinePos(), overlinePos(), strikeOutPos()
*/
qreal QFontMetricsF::lineWidth() const
{
    QFontEngine *engine = d->engineForScript(QChar::Script_Common);
    Q_ASSERT(engine != 0);
    return engine->lineThickness().toReal();
}

QT_END_NAMESPACE