summaryrefslogtreecommitdiffstats
path: root/src/gui/text/qtexttable.cpp
blob: 9097b4ea33c2e874fd254be30cb164c16fdc2993 (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
/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the QtGui module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** No Commercial Usage
** This file contains pre-release code and may not be distributed.
** You may use this file in accordance with the terms and conditions
** contained in the either Technology Preview License Agreement or the
** Beta Release License Agreement.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain
** additional rights. These rights are described in the Nokia Qt LGPL
** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this
** package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** If you are unsure which license is appropriate for your use, please
** contact the sales department at http://qt.nokia.com/contact.
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qtexttable.h"
#include "qtextcursor.h"
#include "qtextformat.h"
#include <qdebug.h>
#include "qtexttable_p.h"
#include "qvarlengtharray.h"
#include "private/qfunctions_p.h"

#include <stdlib.h>

QT_BEGIN_NAMESPACE

/*!
    \class QTextTableCell
    \reentrant

    \brief The QTextTableCell class represents the properties of a
    cell in a QTextTable.

    \ingroup text

    Table cells are pieces of document structure that belong to a table.
    The table orders cells into particular rows and columns; cells can
    also span multiple columns and rows.

    Cells are usually created when a table is inserted into a document with
    QTextCursor::insertTable(), but they are also created and destroyed when
    a table is resized.

    Cells contain information about their location in a table; you can
    obtain the row() and column() numbers of a cell, and its rowSpan()
    and columnSpan().

    The format() of a cell describes the default character format of its
    contents. The firstCursorPosition() and lastCursorPosition() functions
    are used to obtain the extent of the cell in the document.

    \sa QTextTable QTextTableFormat
*/

/*!
    \fn QTextTableCell::QTextTableCell()

    Constructs an invalid table cell.

    \sa isValid()
*/

/*!
    \fn QTextTableCell::QTextTableCell(const QTextTableCell &other)

    Copy constructor. Creates a new QTextTableCell object based on the
    \a other cell.
*/

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

    Assigns the \a other table cell to this table cell.
*/

/*!
    \since 4.2

    Sets the cell's character format to \a format. This can for example be used to change
    the background color of the entire cell:

    QTextTableCell cell = table->cellAt(2, 3);
    QTextCharFormat format = cell.format();
    format.setBackground(Qt::blue);
    cell.setFormat(format);

    Note that the cell's row or column span cannot be changed through this function. You have
    to use QTextTable::mergeCells and QTextTable::splitCell instead.

    \sa format()
*/
void QTextTableCell::setFormat(const QTextCharFormat &format)
{
    QTextCharFormat fmt = format;
    fmt.clearProperty(QTextFormat::ObjectIndex);
    fmt.setObjectType(QTextFormat::TableCellObject);
    QTextDocumentPrivate *p = table->docHandle();
    QTextDocumentPrivate::FragmentIterator frag(&p->fragmentMap(), fragment);

    QTextFormatCollection *c = p->formatCollection();
    QTextCharFormat oldFormat = c->charFormat(frag->format);
    fmt.setTableCellRowSpan(oldFormat.tableCellRowSpan());
    fmt.setTableCellColumnSpan(oldFormat.tableCellColumnSpan());

    p->setCharFormat(frag.position(), 1, fmt, QTextDocumentPrivate::SetFormatAndPreserveObjectIndices);
}

/*!
    Returns the cell's character format.
*/
QTextCharFormat QTextTableCell::format() const
{
    QTextDocumentPrivate *p = table->docHandle();
    QTextFormatCollection *c = p->formatCollection();

    QTextCharFormat fmt = c->charFormat(tableCellFormatIndex());
    fmt.setObjectType(QTextFormat::TableCellObject);
    return fmt;
}

/*!
    \since 4.5

    Returns the index of the tableCell's format in the document's internal list of formats.

    \sa QTextDocument::allFormats()
*/
int QTextTableCell::tableCellFormatIndex() const
{
    QTextDocumentPrivate *p = table->docHandle();
    return QTextDocumentPrivate::FragmentIterator(&p->fragmentMap(), fragment)->format;
}

/*!
    Returns the number of the row in the table that contains this cell.

    \sa column()
*/
int QTextTableCell::row() const
{
    const QTextTablePrivate *tp = table->d_func();
    if (tp->dirty)
        tp->update();

    int idx = tp->findCellIndex(fragment);
    if (idx == -1)
        return idx;
    return tp->cellIndices.at(idx) / tp->nCols;
}

/*!
    Returns the number of the column in the table that contains this cell.

    \sa row()
*/
int QTextTableCell::column() const
{
    const QTextTablePrivate *tp = table->d_func();
    if (tp->dirty)
        tp->update();

    int idx = tp->findCellIndex(fragment);
    if (idx == -1)
        return idx;
    return tp->cellIndices.at(idx) % tp->nCols;
}

/*!
    Returns the number of rows this cell spans. The default is 1.

    \sa columnSpan()
*/
int QTextTableCell::rowSpan() const
{
    return format().tableCellRowSpan();
}

/*!
    Returns the number of columns this cell spans. The default is 1.

    \sa rowSpan()
*/
int QTextTableCell::columnSpan() const
{
    return format().tableCellColumnSpan();
}

/*!
    \fn bool QTextTableCell::isValid() const

    Returns true if this is a valid table cell; otherwise returns
    false.
*/


/*!
    Returns the first valid cursor position in this cell.

    \sa lastCursorPosition()
*/
QTextCursor QTextTableCell::firstCursorPosition() const
{
    return QTextCursor(table->d_func()->pieceTable, firstPosition());
}

/*!
    Returns the last valid cursor position in this cell.

    \sa firstCursorPosition()
*/
QTextCursor QTextTableCell::lastCursorPosition() const
{
    return QTextCursor(table->d_func()->pieceTable, lastPosition());
}


/*!
    \internal

    Returns the first valid position in the document occupied by this cell.
*/
int QTextTableCell::firstPosition() const
{
    QTextDocumentPrivate *p = table->docHandle();
    return p->fragmentMap().position(fragment) + 1;
}

/*!
    \internal

    Returns the last valid position in the document occupied by this cell.
*/
int QTextTableCell::lastPosition() const
{
    QTextDocumentPrivate *p = table->docHandle();
    const QTextTablePrivate *td = table->d_func();
    int index = table->d_func()->findCellIndex(fragment);
    int f;
    if (index != -1)
        f = td->cells.value(index + 1, td->fragment_end);
    else
        f = td->fragment_end;
    return p->fragmentMap().position(f);
}


/*!
    Returns a frame iterator pointing to the beginning of the table's cell.

    \sa end()
*/
QTextFrame::iterator QTextTableCell::begin() const
{
    QTextDocumentPrivate *p = table->docHandle();
    int b = p->blockMap().findNode(firstPosition());
    int e = p->blockMap().findNode(lastPosition()+1);
    return QTextFrame::iterator(const_cast<QTextTable *>(table), b, b, e);
}

/*!
    Returns a frame iterator pointing to the end of the table's cell.

    \sa begin()
*/
QTextFrame::iterator QTextTableCell::end() const
{
    QTextDocumentPrivate *p = table->docHandle();
    int b = p->blockMap().findNode(firstPosition());
    int e = p->blockMap().findNode(lastPosition()+1);
    return QTextFrame::iterator(const_cast<QTextTable *>(table), e, b, e);
}


/*!
    \fn QTextCursor QTextTableCell::operator==(const QTextTableCell &other) const

    Returns true if this cell object and the \a other cell object
    describe the same cell; otherwise returns false.
*/

/*!
    \fn QTextCursor QTextTableCell::operator!=(const QTextTableCell &other) const

    Returns true if this cell object and the \a other cell object
    describe different cells; otherwise returns false.
*/

/*!
    \fn QTextTableCell::~QTextTableCell()

    Destroys the table cell.
*/

QTextTablePrivate::~QTextTablePrivate()
{
    if (grid)
        free(grid);
}


QTextTable *QTextTablePrivate::createTable(QTextDocumentPrivate *pieceTable, int pos, int rows, int cols, const QTextTableFormat &tableFormat)
{
    QTextTableFormat fmt = tableFormat;
    fmt.setColumns(cols);
    QTextTable *table = qobject_cast<QTextTable *>(pieceTable->createObject(fmt));
    Q_ASSERT(table);

    pieceTable->beginEditBlock();

//     qDebug("---> createTable: rows=%d, cols=%d at %d", rows, cols, pos);
    // add block after table
    QTextCharFormat charFmt;
    charFmt.setObjectIndex(table->objectIndex());
    charFmt.setObjectType(QTextFormat::TableCellObject);


    int charIdx = pieceTable->formatCollection()->indexForFormat(charFmt);
    int cellIdx = pieceTable->formatCollection()->indexForFormat(QTextBlockFormat());

    QTextTablePrivate *d = table->d_func();
    d->blockFragmentUpdates = true;

    d->fragment_start = pieceTable->insertBlock(QTextBeginningOfFrame, pos, cellIdx, charIdx);
    d->cells.append(d->fragment_start);
    ++pos;

    for (int i = 1; i < rows*cols; ++i) {
        d->cells.append(pieceTable->insertBlock(QTextBeginningOfFrame, pos, cellIdx, charIdx));
// 	    qDebug("      addCell at %d", pos);
        ++pos;
    }

    d->fragment_end = pieceTable->insertBlock(QTextEndOfFrame, pos, cellIdx, charIdx);
// 	qDebug("      addEOR at %d", pos);
    ++pos;

    d->blockFragmentUpdates = false;
    d->dirty = true;

    pieceTable->endEditBlock();

    return table;
}

struct QFragmentFindHelper
{
    inline QFragmentFindHelper(int _pos, const QTextDocumentPrivate::FragmentMap &map)
        : pos(_pos), fragmentMap(map) {}
    uint pos;
    const QTextDocumentPrivate::FragmentMap &fragmentMap;
};

Q_STATIC_GLOBAL_INLINE_OPERATOR bool operator<(int fragment, const QFragmentFindHelper &helper)
{
    return helper.fragmentMap.position(fragment) < helper.pos;
}

Q_STATIC_GLOBAL_INLINE_OPERATOR bool operator<(const QFragmentFindHelper &helper, int fragment)
{
    return helper.pos < helper.fragmentMap.position(fragment);
}

int QTextTablePrivate::findCellIndex(int fragment) const
{
    QFragmentFindHelper helper(pieceTable->fragmentMap().position(fragment),
                              pieceTable->fragmentMap());
    QList<int>::ConstIterator it = qBinaryFind(cells.begin(), cells.end(), helper);
    if (it == cells.end())
        return -1;
    return it - cells.begin();
}

void QTextTablePrivate::fragmentAdded(const QChar &type, uint fragment)
{
    dirty = true;
    if (blockFragmentUpdates)
        return;
    if (type == QTextBeginningOfFrame) {
        Q_ASSERT(cells.indexOf(fragment) == -1);
        const uint pos = pieceTable->fragmentMap().position(fragment);
        QFragmentFindHelper helper(pos, pieceTable->fragmentMap());
        QList<int>::Iterator it = qLowerBound(cells.begin(), cells.end(), helper);
        cells.insert(it, fragment);
        if (!fragment_start || pos < pieceTable->fragmentMap().position(fragment_start))
            fragment_start = fragment;
        return;
    }
    QTextFramePrivate::fragmentAdded(type, fragment);
}

void QTextTablePrivate::fragmentRemoved(const QChar &type, uint fragment)
{
    dirty = true;
    if (blockFragmentUpdates)
        return;
    if (type == QTextBeginningOfFrame) {
        Q_ASSERT(cells.indexOf(fragment) != -1);
        cells.removeAll(fragment);
        if (fragment_start == fragment && cells.size()) {
            fragment_start = cells.at(0);
        }
        if (fragment_start != fragment)
            return;
    }
    QTextFramePrivate::fragmentRemoved(type, fragment);
}

void QTextTablePrivate::update() const
{
    Q_Q(const QTextTable);
    nCols = q->format().columns();
    nRows = (cells.size() + nCols-1)/nCols;
//     qDebug(">>>> QTextTablePrivate::update, nRows=%d, nCols=%d", nRows, nCols);

    grid = (int *)realloc(grid, nRows*nCols*sizeof(int));
    memset(grid, 0, nRows*nCols*sizeof(int));

    QTextDocumentPrivate *p = pieceTable;
    QTextFormatCollection *c = p->formatCollection();

    cellIndices.resize(cells.size());

    int cell = 0;
    for (int i = 0; i < cells.size(); ++i) {
        int fragment = cells.at(i);
        QTextCharFormat fmt = c->charFormat(QTextDocumentPrivate::FragmentIterator(&p->fragmentMap(), fragment)->format);
        int rowspan = fmt.tableCellRowSpan();
        int colspan = fmt.tableCellColumnSpan();

        // skip taken cells
        while (cell < nRows*nCols && grid[cell])
            ++cell;

        int r = cell/nCols;
        int c = cell%nCols;
        cellIndices[i] = cell;

        if (r + rowspan > nRows) {
            grid = (int *)realloc(grid, sizeof(int)*(r + rowspan)*nCols);
            memset(grid + (nRows*nCols), 0, sizeof(int)*(r+rowspan-nRows)*nCols);
            nRows = r + rowspan;
        }

        Q_ASSERT(c + colspan <= nCols);
        for (int ii = 0; ii < rowspan; ++ii) {
            for (int jj = 0; jj < colspan; ++jj) {
                Q_ASSERT(grid[(r+ii)*nCols + c+jj] == 0);
                grid[(r+ii)*nCols + c+jj] = fragment;
//  		    qDebug("    setting cell %d span=%d/%d at %d/%d", fragment, rowspan, colspan, r+ii, c+jj);
            }
        }
    }
//     qDebug("<<<< end: nRows=%d, nCols=%d", nRows, nCols);

    dirty = false;
}





/*!
    \class QTextTable
    \reentrant

    \brief The QTextTable class represents a table in a QTextDocument.

    \ingroup text

    A table is a group of cells ordered into rows and columns. Each table
    contains at least one row and one column. Each cell contains a block, and
    is surrounded by a frame.

    Tables are usually created and inserted into a document with the
    QTextCursor::insertTable() function.
    For example, we can insert a table with three rows and two columns at the
    current cursor position in an editor using the following lines of code:

    \snippet doc/src/snippets/textdocument-tables/mainwindow.cpp 1
    \codeline
    \snippet doc/src/snippets/textdocument-tables/mainwindow.cpp 3

    The table format is either defined when the table is created or changed
    later with setFormat().

    The table currently being edited by the cursor is found with
    QTextCursor::currentTable(). This allows its format or dimensions to be
    changed after it has been inserted into a document.

    A table's size can be changed with resize(), or by using
    insertRows(), insertColumns(), removeRows(), or removeColumns().
    Use cellAt() to retrieve table cells.

    The starting and ending positions of table rows can be found by moving
    a cursor within a table, and using the rowStart() and rowEnd() functions
    to obtain cursors at the start and end of each row.

    Rows and columns within a QTextTable can be merged and split using
    the mergeCells() and splitCell() functions. However, only cells that span multiple
    rows or columns can be split. (Merging or splitting does not increase or decrease
    the number of rows and columns.) 

    Note that if you have merged multiple columns and rows into one cell, you will not
    be able to split the merged cell into new cells spanning over more than one row 
    or column. To be able to split cells spanning over several rows and columns you 
    need to do this over several iterations.

    \table 80%
    \row
        \o \inlineimage texttable-split.png Original Table
        \o Suppose we have a 2x3 table of names and addresses. To merge both
        columns in the first row we invoke mergeCells() with \a row = 0,
        \a column = 0, \a numRows = 1 and \a numColumns = 2.
        \snippet doc/src/snippets/textdocument-texttable/main.cpp 0

    \row
        \o \inlineimage texttable-merge.png
        \o  This gives us the following table. To split the first row of the table
        back into two cells, we invoke the splitCell() function with \a numRows
        and \a numCols = 1.
        \snippet doc/src/snippets/textdocument-texttable/main.cpp 1

    \row
        \o \inlineimage texttable-split.png Split Table
        \o This results in the original table.
    \endtable

    \sa QTextTableFormat
*/

/*! \internal
 */
QTextTable::QTextTable(QTextDocument *doc)
    : QTextFrame(*new QTextTablePrivate(doc), doc)
{
}

/*! \internal

Destroys the table.
 */
QTextTable::~QTextTable()
{
}


/*!
    \fn QTextTableCell QTextTable::cellAt(int row, int column) const

    Returns the table cell at the given \a row and \a column in the table.

    \sa columns() rows()
*/
QTextTableCell QTextTable::cellAt(int row, int col) const
{
    Q_D(const QTextTable);
    if (d->dirty)
        d->update();

    if (row < 0 || row >= d->nRows || col < 0 || col >= d->nCols)
        return QTextTableCell();

    return QTextTableCell(this, d->grid[row*d->nCols + col]);
}

/*!
    \overload

    Returns the table cell that contains the character at the given \a position
    in the document.
*/
QTextTableCell QTextTable::cellAt(int position) const
{
    Q_D(const QTextTable);
    if (d->dirty)
        d->update();

    uint pos = (uint)position;
    const QTextDocumentPrivate::FragmentMap &map = d->pieceTable->fragmentMap();
    if (position < 0 || map.position(d->fragment_start) >= pos || map.position(d->fragment_end) < pos)
        return QTextTableCell();

    QFragmentFindHelper helper(position, map);
    QList<int>::ConstIterator it = qLowerBound(d->cells.begin(), d->cells.end(), helper);
    if (it != d->cells.begin())
        --it;

    return QTextTableCell(this, *it);
}

/*!
    \fn QTextTableCell QTextTable::cellAt(const QTextCursor &cursor) const

    \overload

    Returns the table cell containing the given \a cursor.
*/
QTextTableCell QTextTable::cellAt(const QTextCursor &c) const
{
    return cellAt(c.position());
}

/*!
    \fn void QTextTable::resize(int rows, int columns)

    Resizes the table to contain the required number of \a rows and \a columns.

    \sa insertRows() insertColumns() removeRows() removeColumns()
*/
void QTextTable::resize(int rows, int cols)
{
    Q_D(QTextTable);
    if (d->dirty)
        d->update();

    int nRows = this->rows();
    int nCols = this->columns();

    if (rows == nRows && cols == nCols)
	return;

    d->pieceTable->beginEditBlock();

    if (nCols < cols)
        insertColumns(nCols, cols - nCols);
    else if (nCols > cols)
        removeColumns(cols, nCols - cols);

    if (nRows < rows)
        insertRows(nRows, rows-nRows);
    else if (nRows > rows)
        removeRows(rows, nRows-rows);

    d->pieceTable->endEditBlock();
}

/*!
    \fn void QTextTable::insertRows(int index, int rows)

    Inserts a number of \a rows before the row with the specified \a index.

    \sa resize() insertColumns() removeRows() removeColumns() appendRows() appendColumns()
*/
void QTextTable::insertRows(int pos, int num)
{
    Q_D(QTextTable);
    if (num <= 0)
	return;

    if (d->dirty)
        d->update();

    if (pos > d->nRows || pos < 0)
        pos = d->nRows;

//     qDebug() << "-------- insertRows" << pos << num;
    QTextDocumentPrivate *p = d->pieceTable;
    QTextFormatCollection *c = p->formatCollection();
    p->beginEditBlock();

    int extended = 0;
    int insert_before = 0;
    if (pos > 0 && pos < d->nRows) {
        for (int i = 0; i < d->nCols; ++i) {
            int cell = d->grid[pos*d->nCols + i];
            if (cell == d->grid[(pos-1)*d->nCols+i]) {
                // cell spans the insertion place, extend it
                QTextDocumentPrivate::FragmentIterator it(&p->fragmentMap(), cell);
                QTextCharFormat fmt = c->charFormat(it->format);
                fmt.setTableCellRowSpan(fmt.tableCellRowSpan() + num);
                p->setCharFormat(it.position(), 1, fmt);
                extended++;
            } else if (!insert_before) {
                insert_before = cell;
            }
        }
    } else {
        insert_before = (pos == 0 ? d->grid[0] : d->fragment_end);
    }
    if (extended < d->nCols) {
        Q_ASSERT(insert_before);
        QTextDocumentPrivate::FragmentIterator it(&p->fragmentMap(), insert_before);
        QTextCharFormat fmt = c->charFormat(it->format);
        fmt.setTableCellRowSpan(1);
        fmt.setTableCellColumnSpan(1);
        Q_ASSERT(fmt.objectIndex() == objectIndex());
        int pos = it.position();
        int cfmt = p->formatCollection()->indexForFormat(fmt);
        int bfmt = p->formatCollection()->indexForFormat(QTextBlockFormat());
//         qDebug("inserting %d cells, nCols=%d extended=%d", num*(d->nCols-extended), d->nCols, extended);
        for (int i = 0; i < num*(d->nCols-extended); ++i)
            p->insertBlock(QTextBeginningOfFrame, pos, bfmt, cfmt, QTextUndoCommand::MoveCursor);
    }

//     qDebug() << "-------- end insertRows" << pos << num;
    p->endEditBlock();
}

/*!
    \fn void QTextTable::insertColumns(int index, int columns)

    Inserts a number of \a columns before the column with the specified \a index.

    \sa insertRows() resize() removeRows() removeColumns() appendRows() appendColumns()
*/
void QTextTable::insertColumns(int pos, int num)
{
    Q_D(QTextTable);
    if (num <= 0)
	return;

    if (d->dirty)
        d->update();

    if (pos > d->nCols || pos < 0)
        pos = d->nCols;

//     qDebug() << "-------- insertCols" << pos << num;
    QTextDocumentPrivate *p = d->pieceTable;
    QTextFormatCollection *c = p->formatCollection();
    p->beginEditBlock();

    for (int i = 0; i < d->nRows; ++i) {
        int cell;
        if (i == d->nRows - 1 && pos == d->nCols)
            cell = d->fragment_end;
        else
            cell = d->grid[i*d->nCols + pos];
        QTextDocumentPrivate::FragmentIterator it(&p->fragmentMap(), cell);
        QTextCharFormat fmt = c->charFormat(it->format);
        if (pos > 0 && pos < d->nCols && cell == d->grid[i*d->nCols + pos - 1]) {
            // cell spans the insertion place, extend it
            fmt.setTableCellColumnSpan(fmt.tableCellColumnSpan() + num);
            p->setCharFormat(it.position(), 1, fmt);
        } else {
            fmt.setTableCellRowSpan(1);
            fmt.setTableCellColumnSpan(1);
            Q_ASSERT(fmt.objectIndex() == objectIndex());
            int position = it.position();
            int cfmt = p->formatCollection()->indexForFormat(fmt);
            int bfmt = p->formatCollection()->indexForFormat(QTextBlockFormat());
            for (int i = 0; i < num; ++i)
                p->insertBlock(QTextBeginningOfFrame, position, bfmt, cfmt, QTextUndoCommand::MoveCursor);
        }
    }

    QTextTableFormat tfmt = format();
    tfmt.setColumns(tfmt.columns()+num);
    QVector<QTextLength> columnWidths = tfmt.columnWidthConstraints();
    if (! columnWidths.isEmpty()) {
        for (int i = num; i > 0; --i)
            columnWidths.insert(pos, columnWidths[qMax(0, pos-1)]);
    }
    tfmt.setColumnWidthConstraints (columnWidths);
    QTextObject::setFormat(tfmt);

//     qDebug() << "-------- end insertCols" << pos << num;
    p->endEditBlock();
}

/*!
    \since 4.5
    Appends \a count rows at the bottom of the table.

    \sa insertColumns() insertRows() resize() removeRows() removeColumns() appendColumns()
*/
void QTextTable::appendRows(int count)
{
    insertRows(rows(), count);
}

/*!
    \since 4.5
    Appends \a count columns at the right side of the table.

    \sa insertColumns() insertRows() resize() removeRows() removeColumns() appendRows()
*/
void QTextTable::appendColumns(int count)
{
    insertColumns(columns(), count);
}

/*!
    \fn void QTextTable::removeRows(int index, int rows)

    Removes a number of \a rows starting with the row at the specified \a index.

    \sa insertRows(), insertColumns(), resize(), removeColumns() appendRows() appendColumns()
*/
void QTextTable::removeRows(int pos, int num)
{
    Q_D(QTextTable);
//     qDebug() << "-------- removeRows" << pos << num;

    if (num <= 0 || pos < 0)
        return;
    if (d->dirty)
        d->update();
    if (pos >= d->nRows)
        return;
    if (pos+num > d->nRows)
        num = d->nRows - pos;

    QTextDocumentPrivate *p = d->pieceTable;
    QTextFormatCollection *collection = p->formatCollection();
    p->beginEditBlock();

    // delete whole table?
    if (pos == 0 && num == d->nRows) {
        const int pos = p->fragmentMap().position(d->fragment_start);
        p->remove(pos, p->fragmentMap().position(d->fragment_end) - pos + 1);
        p->endEditBlock();
        return;
    }

    p->aboutToRemoveCell(cellAt(pos, 0).firstPosition(), cellAt(pos + num - 1, d->nCols - 1).lastPosition());

    QList<int> touchedCells;
    for (int r = pos; r < pos + num; ++r) {
        for (int c = 0; c < d->nCols; ++c) {
            int cell = d->grid[r*d->nCols + c];
            if (touchedCells.contains(cell))
                continue;
            touchedCells << cell;
            QTextDocumentPrivate::FragmentIterator it(&p->fragmentMap(), cell);
            QTextCharFormat fmt = collection->charFormat(it->format);
            int span = fmt.tableCellRowSpan();
            if (span > 1) {
                fmt.setTableCellRowSpan(span - 1);
                p->setCharFormat(it.position(), 1, fmt);
            } else {
                // remove cell
                int index = d->cells.indexOf(cell) + 1;
                int f_end = index < d->cells.size() ? d->cells.at(index) : d->fragment_end;
                p->remove(it.position(), p->fragmentMap().position(f_end) - it.position());
            }
        }
    }

    p->endEditBlock();
//     qDebug() << "-------- end removeRows" << pos << num;
}

/*!
    \fn void QTextTable::removeColumns(int index, int columns)

    Removes a number of \a columns starting with the column at the specified
    \a index.

    \sa insertRows() insertColumns() removeRows() resize() appendRows() appendColumns()
*/
void QTextTable::removeColumns(int pos, int num)
{
    Q_D(QTextTable);
//     qDebug() << "-------- removeCols" << pos << num;

    if (num <= 0 || pos < 0)
	return;
    if (d->dirty)
        d->update();
    if (pos >= d->nCols)
        return;
    if (pos + num > d->nCols)
        pos = d->nCols - num;

    QTextDocumentPrivate *p = d->pieceTable;
    QTextFormatCollection *collection = p->formatCollection();
    p->beginEditBlock();

    // delete whole table?
    if (pos == 0 && num == d->nCols) {
        const int pos = p->fragmentMap().position(d->fragment_start);
        p->remove(pos, p->fragmentMap().position(d->fragment_end) - pos + 1);
        p->endEditBlock();
        return;
    }

    p->aboutToRemoveCell(cellAt(0, pos).firstPosition(), cellAt(d->nRows - 1, pos + num - 1).lastPosition());

    QList<int> touchedCells;
    for (int r = 0; r < d->nRows; ++r) {
        for (int c = pos; c < pos + num; ++c) {
            int cell = d->grid[r*d->nCols + c];
            if (touchedCells.contains(cell))
                continue;
            touchedCells << cell;
            QTextDocumentPrivate::FragmentIterator it(&p->fragmentMap(), cell);
            QTextCharFormat fmt = collection->charFormat(it->format);
            int span = fmt.tableCellColumnSpan();
            if (span > 1) {
                fmt.setTableCellColumnSpan(span - 1);
                p->setCharFormat(it.position(), 1, fmt);
            } else {
                // remove cell
                int index = d->cells.indexOf(cell) + 1;
                int f_end = index < d->cells.size() ? d->cells.at(index) : d->fragment_end;
                p->remove(it.position(), p->fragmentMap().position(f_end) - it.position());
            }
        }
    }

    QTextTableFormat tfmt = format();
    tfmt.setColumns(tfmt.columns()-num);
    QVector<QTextLength> columnWidths = tfmt.columnWidthConstraints();
    if (columnWidths.count() > pos) {
        columnWidths.remove(pos, num);
        tfmt.setColumnWidthConstraints (columnWidths);
    }
    QTextObject::setFormat(tfmt);

    p->endEditBlock();
//     qDebug() << "-------- end removeCols" << pos << num;
}

/*!
    \since 4.1

    Merges the cell at the specified \a row and \a column with the adjacent cells
    into one cell. The new cell will span \a numRows rows and \a numCols columns.
    If \a numRows or \a numCols is less than the current number of rows or columns
    the cell spans then this method does nothing.

    \sa splitCell()
*/
void QTextTable::mergeCells(int row, int column, int numRows, int numCols)
{
    Q_D(QTextTable);

    if (d->dirty)
        d->update();

    QTextDocumentPrivate *p = d->pieceTable;
    QTextFormatCollection *fc = p->formatCollection();

    const QTextTableCell cell = cellAt(row, column);
    if (!cell.isValid() || row != cell.row() || column != cell.column())
        return;

    QTextCharFormat fmt = cell.format();
    const int rowSpan = fmt.tableCellRowSpan();
    const int colSpan = fmt.tableCellColumnSpan();

    numRows = qMin(numRows, rows() - cell.row());
    numCols = qMin(numCols, columns() - cell.column());

    // nothing to merge?
    if (numRows < rowSpan || numCols < colSpan)
        return;

    // check the edges of the merge rect to make sure no cell spans the edge
    for (int r = row; r < row + numRows; ++r) {
        if (cellAt(r, column) == cellAt(r, column - 1))
            return;
        if (cellAt(r, column + numCols) == cellAt(r, column + numCols - 1))
            return;
    }

    for (int c = column; c < column + numCols; ++c) {
        if (cellAt(row, c) == cellAt(row - 1, c))
            return;
        if (cellAt(row + numRows, c) == cellAt(row + numRows - 1, c))
            return;
    }

    p->beginEditBlock();

    const int origCellPosition = cell.firstPosition() - 1;

    const int cellFragment = d->grid[row * d->nCols + column];

    // find the position at which to insert the contents of the merged cells
    QFragmentFindHelper helper(origCellPosition, p->fragmentMap());
    QList<int>::Iterator it = qBinaryFind(d->cells.begin(), d->cells.end(), helper);
    Q_ASSERT(it != d->cells.end());
    Q_ASSERT(*it == cellFragment);
    const int insertCellIndex = it - d->cells.begin();
    int insertFragment = d->cells.value(insertCellIndex + 1, d->fragment_end);
    uint insertPos = p->fragmentMap().position(insertFragment);

    d->blockFragmentUpdates = true;

    bool rowHasText = cell.firstCursorPosition().block().length();
    bool needsParagraph = rowHasText && colSpan == numCols;

    // find all cells that will be erased by the merge
    for (int r = row; r < row + numRows; ++r) {
        int firstColumn = r < row + rowSpan ? column + colSpan : column;

        // don't recompute the cell index for the first row
        int firstCellIndex = r == row ? insertCellIndex + 1 : -1;
        int cellIndex = firstCellIndex;

        for (int c = firstColumn; c < column + numCols; ++c) {
            const int fragment = d->grid[r * d->nCols + c];

            // already handled?
            if (fragment == cellFragment)
                continue;

            QTextDocumentPrivate::FragmentIterator it(&p->fragmentMap(), fragment);
            uint pos = it.position();

            if (firstCellIndex == -1) {
                QFragmentFindHelper helper(pos, p->fragmentMap());
                QList<int>::Iterator it = qBinaryFind(d->cells.begin(), d->cells.end(), helper);
                Q_ASSERT(it != d->cells.end());
                Q_ASSERT(*it == fragment);
                firstCellIndex = cellIndex = it - d->cells.begin();
            }

            ++cellIndex;

            QTextCharFormat fmt = fc->charFormat(it->format);

            const int cellRowSpan = fmt.tableCellRowSpan();
            const int cellColSpan = fmt.tableCellColumnSpan();

            // update the grid for this cell
            for (int i = r; i < r + cellRowSpan; ++i)
                for (int j = c; j < c + cellColSpan; ++j)
                    d->grid[i * d->nCols + j] = cellFragment;

            // erase the cell marker
            p->remove(pos, 1);

            const int nextFragment = d->cells.value(cellIndex, d->fragment_end);
            const uint nextPos = p->fragmentMap().position(nextFragment);

            Q_ASSERT(nextPos >= pos);

            // merge the contents of the cell (if not empty)
            if (nextPos > pos) {
                if (needsParagraph) {
                    needsParagraph = false;
                    QTextCursor(p, insertPos++).insertBlock();
                    p->move(pos + 1, insertPos, nextPos - pos);
                } else if (rowHasText) {
                    QTextCursor(p, insertPos++).insertText(QLatin1String(" "));
                    p->move(pos + 1, insertPos, nextPos - pos);
                } else {
                    p->move(pos, insertPos, nextPos - pos);
                }

                insertPos += nextPos - pos;
                rowHasText = true;
            }
        }

        if (rowHasText) {
            needsParagraph = true;
            rowHasText = false;
        }

        // erase cells from last row
        if (firstCellIndex >= 0) {
            d->cellIndices.remove(firstCellIndex, cellIndex - firstCellIndex);
            d->cells.erase(d->cells.begin() + firstCellIndex, d->cells.begin() + cellIndex);
        }
    }

    d->fragment_start = d->cells.first();

    fmt.setTableCellRowSpan(numRows);
    fmt.setTableCellColumnSpan(numCols);
    p->setCharFormat(origCellPosition, 1, fmt);

    d->blockFragmentUpdates = false;
    d->dirty = false;

    p->endEditBlock();
}

/*!
    \overload
    \since 4.1

    Merges the cells selected by the provided \a cursor.

    \sa splitCell()
*/
void QTextTable::mergeCells(const QTextCursor &cursor)
{
    if (!cursor.hasComplexSelection())
        return;

    int firstRow, numRows, firstColumn, numColumns;
    cursor.selectedTableCells(&firstRow, &numRows, &firstColumn, &numColumns);
    mergeCells(firstRow, firstColumn, numRows, numColumns);
}

/*!
    \since 4.1

    Splits the specified cell at \a row and \a column into an array of multiple
    cells with dimensions specified by \a numRows and \a numCols.

    \note It is only possible to split cells that span multiple rows or columns, such as rows
    that have been merged using mergeCells().

    \sa mergeCells()
*/
void QTextTable::splitCell(int row, int column, int numRows, int numCols)
{
    Q_D(QTextTable);

    if (d->dirty)
        d->update();

    QTextDocumentPrivate *p = d->pieceTable;
    QTextFormatCollection *c = p->formatCollection();

    const QTextTableCell cell = cellAt(row, column);
    if (!cell.isValid())
        return;
    row = cell.row();
    column = cell.column();

    QTextCharFormat fmt = cell.format();
    const int rowSpan = fmt.tableCellRowSpan();
    const int colSpan = fmt.tableCellColumnSpan();

    // nothing to split?
    if (numRows > rowSpan || numCols > colSpan)
        return;

    p->beginEditBlock();

    const int origCellPosition = cell.firstPosition() - 1;

    QVarLengthArray<int> rowPositions(rowSpan);

    rowPositions[0] = cell.lastPosition();

    for (int r = row + 1; r < row + rowSpan; ++r) {
        // find the cell before which to insert the new cell markers
        int gridIndex = r * d->nCols + column;
        QVector<int>::iterator it = qUpperBound(d->cellIndices.begin(), d->cellIndices.end(), gridIndex);
        int cellIndex = it - d->cellIndices.begin();
        int fragment = d->cells.value(cellIndex, d->fragment_end);
        rowPositions[r - row] = p->fragmentMap().position(fragment);
    }

    fmt.setTableCellColumnSpan(1);
    fmt.setTableCellRowSpan(1);
    const int fmtIndex = c->indexForFormat(fmt);
    const int blockIndex = p->blockMap().find(cell.lastPosition())->format;

    int insertAdjustement = 0;
    for (int i = 0; i < numRows; ++i) {
        for (int c = 0; c < colSpan - numCols; ++c)
            p->insertBlock(QTextBeginningOfFrame, rowPositions[i] + insertAdjustement + c, blockIndex, fmtIndex);
        insertAdjustement += colSpan - numCols;
    }

    for (int i = numRows; i < rowSpan; ++i) {
        for (int c = 0; c < colSpan; ++c)
            p->insertBlock(QTextBeginningOfFrame, rowPositions[i] + insertAdjustement + c, blockIndex, fmtIndex);
        insertAdjustement += colSpan;
    }

    fmt.setTableCellRowSpan(numRows);
    fmt.setTableCellColumnSpan(numCols);
    p->setCharFormat(origCellPosition, 1, fmt);

    p->endEditBlock();
}

/*!
    Returns the number of rows in the table.

    \sa columns()
*/
int QTextTable::rows() const
{
    Q_D(const QTextTable);
    if (d->dirty)
        d->update();

    return d->nRows;
}

/*!
    Returns the number of columns in the table.

    \sa rows()
*/
int QTextTable::columns() const
{
    Q_D(const QTextTable);
    if (d->dirty)
        d->update();

    return d->nCols;
}

#if 0
void QTextTable::mergeCells(const QTextCursor &selection)
{
}
#endif

/*!
    \fn QTextCursor QTextTable::rowStart(const QTextCursor &cursor) const

    Returns a cursor pointing to the start of the row that contains the
    given \a cursor.

    \sa rowEnd()
*/
QTextCursor QTextTable::rowStart(const QTextCursor &c) const
{
    Q_D(const QTextTable);
    QTextTableCell cell = cellAt(c);
    if (!cell.isValid())
        return QTextCursor();

    int row = cell.row();
    QTextDocumentPrivate *p = d->pieceTable;
    QTextDocumentPrivate::FragmentIterator it(&p->fragmentMap(), d->grid[row*d->nCols]);
    return QTextCursor(p, it.position());
}

/*!
    \fn QTextCursor QTextTable::rowEnd(const QTextCursor &cursor) const

    Returns a cursor pointing to the end of the row that contains the given
    \a cursor.

    \sa rowStart()
*/
QTextCursor QTextTable::rowEnd(const QTextCursor &c) const
{
    Q_D(const QTextTable);
    QTextTableCell cell = cellAt(c);
    if (!cell.isValid())
        return QTextCursor();

    int row = cell.row() + 1;
    int fragment = row < d->nRows ? d->grid[row*d->nCols] : d->fragment_end;
    QTextDocumentPrivate *p = d->pieceTable;
    QTextDocumentPrivate::FragmentIterator it(&p->fragmentMap(), fragment);
    return QTextCursor(p, it.position() - 1);
}

/*!
    \fn void QTextTable::setFormat(const QTextTableFormat &format)

    Sets the table's \a format.

    \sa format()
*/
void QTextTable::setFormat(const QTextTableFormat &format)
{
    QTextTableFormat fmt = format;
    // don't try to change the number of table columns from here
    fmt.setColumns(columns());
    QTextObject::setFormat(fmt);
}

/*!
    \fn QTextTableFormat QTextTable::format() const

    Returns the table's format.

    \sa setFormat()
*/

QT_END_NAMESPACE