summaryrefslogtreecommitdiffstats
path: root/src/gui/painting/qpen.cpp
blob: e9e6d99480c74132a99018ea41bc3ca6409ff202 (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
/****************************************************************************
**
** 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 "qpen.h"
#include "qpen_p.h"
#include "qdatastream.h"
#include "qvariant.h"
#include "qbrush.h"

#include <qdebug.h>

QT_BEGIN_NAMESPACE

typedef QPenPrivate QPenData;

/*!
    \class QPen
    \inmodule QtGui
    \ingroup painting
    \ingroup shared


    \brief The QPen class defines how a QPainter should draw lines and outlines
    of shapes.

    A pen has a style(), width(), brush(), capStyle() and joinStyle().

    The pen style defines the line type. The brush is used to fill
    strokes generated with the pen. Use the QBrush class to specify
    fill styles.  The cap style determines the line end caps that can
    be drawn using QPainter, while the join style describes how joins
    between two lines are drawn. The pen width can be specified in
    both integer (width()) and floating point (widthF()) precision. A
    line width of zero indicates a cosmetic pen.  This means that the
    pen width is always drawn one pixel wide, independent of the \l
    {QPainter#Coordinate Transformations}{transformation} set on the
    painter.

    The various settings can easily be modified using the
    corresponding setStyle(), setWidth(), setBrush(), setCapStyle()
    and setJoinStyle() functions (note that the painter's pen must be
    reset when altering the pen's properties).

    For example:

    \snippet code/src_gui_painting_qpen.cpp 0

    which is equivalent to

    \snippet code/src_gui_painting_qpen.cpp 1

    The default pen is a solid black brush with 1 width, square
    cap style (Qt::SquareCap), and  bevel join style (Qt::BevelJoin).

    In addition QPen provides the color() and setColor()
    convenience functions to extract and set the color of the pen's
    brush, respectively. Pens may also be compared and streamed.

    For more information about painting in general, see the \l{Paint
    System} documentation.

    \tableofcontents

    \section1 Pen Style

    Qt provides several built-in styles represented by the
    Qt::PenStyle enum:

    \table
    \row
    \li \inlineimage qpen-solid.png
    \li \inlineimage qpen-dash.png
    \li \inlineimage qpen-dot.png
    \row
    \li Qt::SolidLine
    \li Qt::DashLine
    \li Qt::DotLine
    \row
    \li \inlineimage qpen-dashdot.png
    \li \inlineimage qpen-dashdotdot.png
    \li \inlineimage qpen-custom.png
    \row
    \li Qt::DashDotLine
    \li Qt::DashDotDotLine
    \li Qt::CustomDashLine
    \endtable

    Simply use the setStyle() function to convert the pen style to
    either of the built-in styles, except the Qt::CustomDashLine style
    which we will come back to shortly. Setting the style to Qt::NoPen
    tells the painter to not draw lines or outlines. The default pen
    style is Qt::SolidLine.

    Since Qt 4.1 it is also possible to specify a custom dash pattern
    using the setDashPattern() function which implicitly converts the
    style of the pen to Qt::CustomDashLine. The pattern argument, a
    QVector, must be specified as an even number of \l qreal entries
    where the entries 1, 3, 5... are the dashes and 2, 4, 6... are the
    spaces. For example, the custom pattern shown above is created
    using the following code:

    \snippet code/src_gui_painting_qpen.cpp 2

    Note that the dash pattern is specified in units of the pens
    width, e.g. a dash of length 5 in width 10 is 50 pixels long.

    The currently set dash pattern can be retrieved using the
    dashPattern() function. Use the isSolid() function to determine
    whether the pen has a solid fill, or not.

    \section1 Cap Style

    The cap style defines how the end points of lines are drawn using
    QPainter.  The cap style only apply to wide lines, i.e. when the
    width is 1 or greater. The Qt::PenCapStyle enum provides the
    following styles:

    \table
    \row
    \li \inlineimage qpen-square.png
    \li \inlineimage qpen-flat.png
    \li \inlineimage qpen-roundcap.png
    \row
    \li Qt::SquareCap
    \li Qt::FlatCap
    \li Qt::RoundCap
    \endtable

    The Qt::SquareCap style is a square line end that covers the end
    point and extends beyond it by half the line width. The
    Qt::FlatCap style is a square line end that does not cover the end
    point of the line. And the Qt::RoundCap style is a rounded line
    end covering the end point.

    The default is Qt::SquareCap.

    Whether or not end points are drawn when the pen width is 0 or 1
    depends on the cap style. Using Qt::SquareCap or Qt::RoundCap they
    are drawn, using Qt::FlatCap they are not drawn.

    \section1 Join Style

    The join style defines how joins between two connected lines can
    be drawn using QPainter. The join style only apply to wide lines,
    i.e. when the width is 1 or greater. The Qt::PenJoinStyle enum
    provides the following styles:

    \table
    \row
    \li \inlineimage qpen-bevel.png
    \li \inlineimage qpen-miter.png
    \li \inlineimage qpen-roundjoin.png
    \row
    \li Qt::BevelJoin
    \li Qt::MiterJoin
    \li Qt::RoundJoin
    \endtable

    The Qt::BevelJoin style fills the triangular notch between the two
    lines. The Qt::MiterJoin style extends the lines to meet at an
    angle. And the Qt::RoundJoin style fills a circular arc between
    the two lines.

    The default is Qt::BevelJoin.

    \image qpen-miterlimit.png

    When the Qt::MiterJoin style is applied, it is possible to use the
    setMiterLimit() function to specify how far the miter join can
    extend from the join point. The miterLimit() is used to reduce
    artifacts between line joins where the lines are close to
    parallel.

    The miterLimit() must be specified in units of the pens width,
    e.g. a miter limit of 5 in width 10 is 50 pixels long. The
    default miter limit is 2, i.e. twice the pen width in pixels.

    \table 100%
    \row
    \li \inlineimage qpen-demo.png
    \li \b {\l {painting/pathstroke}{The Path Stroking Example}}

    The Path Stroking example shows Qt's built-in dash patterns and shows
    how custom patterns can be used to extend the range of available
    patterns.
    \endtable

    \sa QPainter, QBrush, {painting/pathstroke}{Path Stroking Example},
        {Scribble Example}
*/

/*!
  \internal
*/
inline QPenPrivate::QPenPrivate(const QBrush &_brush, qreal _width, Qt::PenStyle penStyle,
                                Qt::PenCapStyle _capStyle, Qt::PenJoinStyle _joinStyle, bool _defaultWidth)
    : ref(1), dashOffset(0), miterLimit(2),
      cosmetic(false), defaultWidth(_defaultWidth)
{
    width = _width;
    brush = _brush;
    style = penStyle;
    capStyle = _capStyle;
    joinStyle = _joinStyle;
}

static const Qt::PenCapStyle qpen_default_cap = Qt::SquareCap;
static const Qt::PenJoinStyle qpen_default_join = Qt::BevelJoin;

class QPenDataHolder
{
public:
    QPenData *pen;
    QPenDataHolder(const QBrush &brush, qreal width, Qt::PenStyle penStyle,
                   Qt::PenCapStyle penCapStyle, Qt::PenJoinStyle _joinStyle)
        : pen(new QPenData(brush, width, penStyle, penCapStyle, _joinStyle))
    { }
    ~QPenDataHolder()
    {
        if (!pen->ref.deref())
            delete pen;
        pen = 0;
    }
};

Q_GLOBAL_STATIC_WITH_ARGS(QPenDataHolder, defaultPenInstance,
                          (Qt::black, 1, Qt::SolidLine, qpen_default_cap, qpen_default_join))
Q_GLOBAL_STATIC_WITH_ARGS(QPenDataHolder, nullPenInstance,
                          (Qt::black, 1, Qt::NoPen, qpen_default_cap, qpen_default_join))

/*!
    Constructs a default black solid line pen with 1 width.
*/

QPen::QPen()
{
    d = defaultPenInstance()->pen;
    d->ref.ref();
}

/*!
    Constructs a black pen with 1 width and the given \a style.

    \sa setStyle()
*/

QPen::QPen(Qt::PenStyle style)
{
    if (style == Qt::NoPen) {
        d = nullPenInstance()->pen;
        d->ref.ref();
    } else {
        d = new QPenData(Qt::black, 1, style, qpen_default_cap, qpen_default_join);
    }
}


/*!
    Constructs a solid line pen with 1 width and the given \a color.

    \sa setBrush(), setColor()
*/

QPen::QPen(const QColor &color)
{
    d = new QPenData(color, 1, Qt::SolidLine, qpen_default_cap, qpen_default_join);
}


/*!
    \fn QPen::QPen(const QBrush &brush, qreal width, Qt::PenStyle style, Qt::PenCapStyle cap, Qt::PenJoinStyle join)

    Constructs a pen with the specified \a brush, \a width, pen \a style,
    \a cap style and \a join style.

    \sa setBrush(), setWidth(), setStyle(), setCapStyle(), setJoinStyle()
*/

QPen::QPen(const QBrush &brush, qreal width, Qt::PenStyle s, Qt::PenCapStyle c, Qt::PenJoinStyle j)
{
    d = new QPenData(brush, width, s, c, j, false);
}

/*!
    \fn QPen::QPen(const QPen &pen)

    Constructs a pen that is a copy of the given \a pen.
*/

QPen::QPen(const QPen &p) Q_DECL_NOTHROW
{
    d = p.d;
    if (d)
        d->ref.ref();
}


/*!
    \fn QPen::QPen(QPen &&pen)
    \since 5.4

    Constructs a pen that is moved from the given \a pen.

    The moved-from pen can only be assigned to, copied, or
    destroyed. Any other operation (prior to assignment) leads to
    undefined behavior.
*/

/*!
    Destroys the pen.
*/

QPen::~QPen()
{
    if (d && !d->ref.deref())
        delete d;
}

/*!
    \fn void QPen::detach()
    Detaches from shared pen data to make sure that this pen is the
    only one referring the data.

    If multiple pens share common data, this pen dereferences the data
    and gets a copy of the data. Nothing is done if there is just a
    single reference.
*/

void QPen::detach()
{
    if (d->ref.load() == 1)
        return;

    QPenData *x = new QPenData(*static_cast<QPenData *>(d));
    if (!d->ref.deref())
        delete d;
    x->ref.store(1);
    d = x;
}


/*!
    \fn QPen &QPen::operator=(const QPen &pen)

    Assigns the given \a pen to this pen and returns a reference to
    this pen.
*/

QPen &QPen::operator=(const QPen &p) Q_DECL_NOTHROW
{
    QPen(p).swap(*this);
    return *this;
}

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

    Move-assigns \a other to this QPen instance.

    \since 5.2
*/

/*!
    \fn void QPen::swap(QPen &other)
    \since 4.8

    Swaps pen \a other with this pen. This operation is very
    fast and never fails.
*/

/*!
   Returns the pen as a QVariant.
*/
QPen::operator QVariant() const
{
    return QVariant(QVariant::Pen, this);
}

/*!
    \fn Qt::PenStyle QPen::style() const

    Returns the pen style.

    \sa setStyle(), {QPen#Pen Style}{Pen Style}
*/
Qt::PenStyle QPen::style() const
{
    return d->style;
}
/*!
    \fn void QPen::setStyle(Qt::PenStyle style)

    Sets the pen style to the given \a style.

    See the \l Qt::PenStyle documentation for a list of the available
    styles. Since Qt 4.1 it is also possible to specify a custom dash
    pattern using the setDashPattern() function which implicitly
    converts the style of the pen to Qt::CustomDashLine.

    \note This function resets the dash offset to zero.

    \sa style(), {QPen#Pen Style}{Pen Style}
*/

void QPen::setStyle(Qt::PenStyle s)
{
    if (d->style == s)
        return;
    detach();
    d->style = s;
    QPenData *dd = static_cast<QPenData *>(d);
    dd->dashPattern.clear();
    dd->dashOffset = 0;
}

/*!
    Returns the dash pattern of this pen.

    \sa style(), isSolid()
 */
QVector<qreal> QPen::dashPattern() const
{
    QPenData *dd = static_cast<QPenData *>(d);
    if (d->style == Qt::SolidLine || d->style == Qt::NoPen) {
        return QVector<qreal>();
    } else if (dd->dashPattern.isEmpty()) {
        const qreal space = 2;
        const qreal dot = 1;
        const qreal dash = 4;

        switch (d->style) {
        case Qt::DashLine:
            dd->dashPattern.reserve(2);
            dd->dashPattern << dash << space;
            break;
        case Qt::DotLine:
            dd->dashPattern.reserve(2);
            dd->dashPattern << dot << space;
            break;
        case Qt::DashDotLine:
            dd->dashPattern.reserve(4);
            dd->dashPattern << dash << space << dot << space;
            break;
        case Qt::DashDotDotLine:
            dd->dashPattern.reserve(6);
            dd->dashPattern << dash << space << dot << space << dot << space;
            break;
        default:
            break;
        }
    }
    return dd->dashPattern;
}

/*!
    Sets the dash pattern for this pen to the given \a pattern. This
    implicitly converts the style of the pen to Qt::CustomDashLine.

    The pattern must be specified as an even number of positive entries
    where the entries 1, 3, 5... are the dashes and 2, 4, 6... are the
    spaces. For example:

    \table 100%
    \row
    \li \inlineimage qpen-custom.png
    \li
    \snippet code/src_gui_painting_qpen.cpp 3
    \endtable

    The dash pattern is specified in units of the pens width; e.g. a
    dash of length 5 in width 10 is 50 pixels long. Note that a pen
    with zero width is equivalent to a cosmetic pen with a width of 1
    pixel.

    Each dash is also subject to cap styles so a dash of 1 with square
    cap set will extend 0.5 pixels out in each direction resulting in
    a total width of 2.

    Note that the default cap style is Qt::SquareCap, meaning that a
    square line end covers the end point and extends beyond it by half
    the line width.

    \sa setStyle(), dashPattern(), setCapStyle(), setCosmetic()
 */
void QPen::setDashPattern(const QVector<qreal> &pattern)
{
    if (pattern.isEmpty())
        return;
    detach();

    QPenData *dd = static_cast<QPenData *>(d);
    dd->dashPattern = pattern;
    d->style = Qt::CustomDashLine;

    if ((dd->dashPattern.size() % 2) == 1) {
        qWarning("QPen::setDashPattern: Pattern not of even length");
        dd->dashPattern << 1;
    }
}


/*!
    Returns the dash offset for the pen.

    \sa setDashOffset()
*/
qreal QPen::dashOffset() const
{
    QPenData *dd = static_cast<QPenData *>(d);
    return dd->dashOffset;
}
/*!
    Sets the dash offset (the starting point on the dash pattern) for this pen
    to the \a offset specified. The offset is measured in terms of the units used
    to specify the dash pattern.

    \table
    \row \li \inlineimage qpen-dashpattern.png
    \li For example, a pattern where each stroke is four units long, followed by a gap
    of two units, will begin with the stroke when drawn as a line.

    However, if the dash offset is set to 4.0, any line drawn will begin with the gap.
    Values of the offset up to 4.0 will cause part of the stroke to be drawn first,
    and values of the offset between 4.0 and 6.0 will cause the line to begin with
    part of the gap.
    \endtable

    \note This implicitly converts the style of the pen to Qt::CustomDashLine.
*/
void QPen::setDashOffset(qreal offset)
{
    if (qFuzzyCompare(offset, static_cast<QPenData *>(d)->dashOffset))
        return;
    detach();
    QPenData *dd = static_cast<QPenData *>(d);
    dd->dashOffset = offset;
    if (d->style != Qt::CustomDashLine) {
        dd->dashPattern = dashPattern();
        d->style = Qt::CustomDashLine;
    }
}

/*!
    Returns the miter limit of the pen. The miter limit is only
    relevant when the join style is set to Qt::MiterJoin.

    \sa setMiterLimit(), {QPen#Join Style}{Join Style}
*/
qreal QPen::miterLimit() const
{
    const QPenData *dd = static_cast<QPenData *>(d);
    return dd->miterLimit;
}

/*!
    Sets the miter limit of this pen to the given \a limit.

    \image qpen-miterlimit.png

    The miter limit describes how far a miter join can extend from the
    join point. This is used to reduce artifacts between line joins
    where the lines are close to parallel.

    This value does only have effect when the pen style is set to
    Qt::MiterJoin. The value is specified in units of the pen's width,
    e.g. a miter limit of 5 in width 10 is 50 pixels long. The default
    miter limit is 2, i.e. twice the pen width in pixels.

    \sa miterLimit(), setJoinStyle(), {QPen#Join Style}{Join Style}
*/
void QPen::setMiterLimit(qreal limit)
{
    detach();
    QPenData *dd = static_cast<QPenData *>(d);
    dd->miterLimit = limit;
}


/*!
    \fn qreal QPen::width() const

    Returns the pen width with integer precision.

    \sa setWidth(), widthF()
*/

int QPen::width() const
{
    return qRound(d->width);
}

/*!
    \fn qreal QPen::widthF() const

    Returns the pen width with floating point precision.

    \sa setWidthF(), width()
*/
qreal QPen::widthF() const
{
    return d->width;
}

/*!
    \fn QPen::setWidth(int width)

    Sets the pen width to the given \a width in pixels with integer
    precision.

    A line width of zero indicates a cosmetic pen. This means that the
    pen width is always drawn one pixel wide, independent of the \l
    {QPainter#Coordinate Transformations}{transformation} set on the
    painter.

    Setting a pen width with a negative value is not supported.

    \sa setWidthF(), width()
*/
void QPen::setWidth(int width)
{
    if (width < 0 || width >= (1 << 15)) {
        qWarning("QPen::setWidth: Setting a pen width that is out of range");
        return;
    }
    if ((qreal)width == d->width)
        return;
    detach();
    d->width = width;
    d->defaultWidth = false;
}

/*!
    Sets the pen width to the given \a width in pixels with floating point
    precision.

    A line width of zero indicates a cosmetic pen. This means that the
    pen width is always drawn one pixel wide, independent of the \l
    {QPainter#Coordinate Transformations}{transformation} on the
    painter.

    Setting a pen width with a negative value is not supported.

    \sa setWidth(), widthF()
*/

void QPen::setWidthF(qreal width)
{
    if (width < 0.f || width >= (1 << 15)) {
        qWarning("QPen::setWidthF: Setting a pen width that is out of range");
        return;
    }
    if (qAbs(d->width - width) < 0.00000001f)
        return;
    detach();
    d->width = width;
    d->defaultWidth = false;
}


/*!
    Returns the pen's cap style.

    \sa setCapStyle(), {QPen#Cap Style}{Cap Style}
*/
Qt::PenCapStyle QPen::capStyle() const
{
    return d->capStyle;
}

/*!
    \fn void QPen::setCapStyle(Qt::PenCapStyle style)

    Sets the pen's cap style to the given \a style. The default value
    is Qt::SquareCap.

    \sa capStyle(), {QPen#Cap Style}{Cap Style}
*/

void QPen::setCapStyle(Qt::PenCapStyle c)
{
    if (d->capStyle == c)
        return;
    detach();
    d->capStyle = c;
}

/*!
    Returns the pen's join style.

    \sa setJoinStyle(), {QPen#Join Style}{Join Style}
*/
Qt::PenJoinStyle QPen::joinStyle() const
{
    return d->joinStyle;
}

/*!
    \fn void QPen::setJoinStyle(Qt::PenJoinStyle style)

    Sets the pen's join style to the given \a style. The default value
    is Qt::BevelJoin.

    \sa joinStyle(), {QPen#Join Style}{Join Style}
*/

void QPen::setJoinStyle(Qt::PenJoinStyle j)
{
    if (d->joinStyle == j)
        return;
    detach();
    d->joinStyle = j;
}

/*!
    \fn const QColor &QPen::color() const

    Returns the color of this pen's brush.

    \sa brush(), setColor()
*/
QColor QPen::color() const
{
    return d->brush.color();
}

/*!
    \fn void QPen::setColor(const QColor &color)

    Sets the color of this pen's brush to the given \a color.

    \sa setBrush(), color()
*/

void QPen::setColor(const QColor &c)
{
    detach();
    d->brush = QBrush(c);
}


/*!
    Returns the brush used to fill strokes generated with this pen.
*/
QBrush QPen::brush() const
{
    return d->brush;
}

/*!
    Sets the brush used to fill strokes generated with this pen to the given
    \a brush.

    \sa brush(), setColor()
*/
void QPen::setBrush(const QBrush &brush)
{
    detach();
    d->brush = brush;
}


/*!
    Returns \c true if the pen has a solid fill, otherwise false.

    \sa style(), dashPattern()
*/
bool QPen::isSolid() const
{
    return d->brush.style() == Qt::SolidPattern;
}


/*!
    Returns \c true if the pen is cosmetic; otherwise returns \c false.

    Cosmetic pens are used to draw strokes that have a constant width
    regardless of any transformations applied to the QPainter they are
    used with. Drawing a shape with a cosmetic pen ensures that its
    outline will have the same thickness at different scale factors.

    A zero width pen is cosmetic by default.

    \sa setCosmetic(), widthF()
*/

bool QPen::isCosmetic() const
{
    QPenData *dd = static_cast<QPenData *>(d);
    return (dd->cosmetic == true) || d->width == 0;
}


/*!
    Sets this pen to cosmetic or non-cosmetic, depending on the value of
    \a cosmetic.

    \sa isCosmetic()
*/

void QPen::setCosmetic(bool cosmetic)
{
    detach();
    QPenData *dd = static_cast<QPenData *>(d);
    dd->cosmetic = cosmetic;
}



/*!
    \fn bool QPen::operator!=(const QPen &pen) const

    Returns \c true if the pen is different from the given \a pen;
    otherwise false. Two pens are different if they have different
    styles, widths or colors.

    \sa operator==()
*/

/*!
    \fn bool QPen::operator==(const QPen &pen) const

    Returns \c true if the pen is equal to the given \a pen; otherwise
    false. Two pens are equal if they have equal styles, widths and
    colors.

    \sa operator!=()
*/

bool QPen::operator==(const QPen &p) const
{
    QPenData *dd = static_cast<QPenData *>(d);
    QPenData *pdd = static_cast<QPenData *>(p.d);
    return (p.d == d)
        || (p.d->style == d->style
            && p.d->capStyle == d->capStyle
            && p.d->joinStyle == d->joinStyle
            && p.d->width == d->width
            && pdd->miterLimit == dd->miterLimit
            && (d->style != Qt::CustomDashLine
                || (qFuzzyCompare(pdd->dashOffset, dd->dashOffset) &&
                    pdd->dashPattern == dd->dashPattern))
            && p.d->brush == d->brush
            && pdd->cosmetic == dd->cosmetic
            && pdd->defaultWidth == dd->defaultWidth);
}


/*!
    \fn bool QPen::isDetached()

    \internal
*/

bool QPen::isDetached()
{
    return d->ref.load() == 1;
}


/*****************************************************************************
  QPen stream functions
 *****************************************************************************/
#ifndef QT_NO_DATASTREAM
/*!
    \fn QDataStream &operator<<(QDataStream &stream, const QPen &pen)
    \relates QPen

    Writes the given \a pen to the given \a stream and returns a reference to
    the \a stream.

    \sa {Serializing Qt Data Types}
*/

QDataStream &operator<<(QDataStream &s, const QPen &p)
{
    QPenData *dd = static_cast<QPenData *>(p.d);
    if (s.version() < 3) {
        s << (quint8)p.style();
    } else if (s.version() < QDataStream::Qt_4_3) {
        s << (quint8)(p.style() | p.capStyle() | p.joinStyle());
    } else {
        s << (quint16)(p.style() | p.capStyle() | p.joinStyle());
        s << (bool)(dd->cosmetic);
    }

    if (s.version() < 7) {
        s << (quint8)p.width();
        s << p.color();
    } else {
        s << double(p.widthF());
        s << p.brush();
        s << double(p.miterLimit());
        if (sizeof(qreal) == sizeof(double)) {
            s << p.dashPattern();
        } else {
            // ensure that we write doubles here instead of streaming the pattern
            // directly; otherwise, platforms that redefine qreal might generate
            // data that cannot be read on other platforms.
            QVector<qreal> pattern = p.dashPattern();
            s << quint32(pattern.size());
            for (int i = 0; i < pattern.size(); ++i)
                s << double(pattern.at(i));
        }
        if (s.version() >= 9)
            s << double(p.dashOffset());
        if (s.version() >= QDataStream::Qt_5_0)
            s << bool(dd->defaultWidth);
    }
    return s;
}

/*!
    \fn QDataStream &operator>>(QDataStream &stream, QPen &pen)
    \relates QPen

    Reads a pen from the given \a stream into the given \a pen and
    returns a reference to the \a stream.

    \sa {Serializing Qt Data Types}
*/

QDataStream &operator>>(QDataStream &s, QPen &p)
{
    quint16 style;
    quint8 width8 = 0;
    double width = 0;
    QColor color;
    QBrush brush;
    double miterLimit = 2;
    QVector<qreal> dashPattern;
    double dashOffset = 0;
    bool cosmetic = false;
    bool defaultWidth = false;
    if (s.version() < QDataStream::Qt_4_3) {
        quint8 style8;
        s >> style8;
        style = style8;
    } else {
        s >> style;
        s >> cosmetic;
    }
    if (s.version() < 7) {
        s >> width8;
        s >> color;
        brush = color;
        width = width8;
    } else {
        s >> width;
        s >> brush;
        s >> miterLimit;
        if (sizeof(qreal) == sizeof(double)) {
            s >> dashPattern;
        } else {
            quint32 numDashes;
            s >> numDashes;
            double dash;
            dashPattern.reserve(numDashes);
            for (quint32 i = 0; i < numDashes; ++i) {
                s >> dash;
                dashPattern << dash;
            }
        }
        if (s.version() >= 9)
            s >> dashOffset;
    }

    if (s.version() >= QDataStream::Qt_5_0) {
        s >> defaultWidth;
    } else {
        // best we can do for legacy pens
        defaultWidth = qFuzzyIsNull(width);
    }

    p.detach();
    QPenData *dd = static_cast<QPenData *>(p.d);
    dd->width = width;
    dd->brush = brush;
    dd->style = Qt::PenStyle(style & Qt::MPenStyle);
    dd->capStyle = Qt::PenCapStyle(style & Qt::MPenCapStyle);
    dd->joinStyle = Qt::PenJoinStyle(style & Qt::MPenJoinStyle);
    dd->dashPattern = dashPattern;
    dd->miterLimit = miterLimit;
    dd->dashOffset = dashOffset;
    dd->cosmetic = cosmetic;
    dd->defaultWidth = defaultWidth;

    return s;
}
#endif //QT_NO_DATASTREAM

#ifndef QT_NO_DEBUG_STREAM
QDebug operator<<(QDebug dbg, const QPen &p)
{
    const char *PEN_STYLES[] = {
        "NoPen",
        "SolidLine",
        "DashLine",
        "DotLine",
        "DashDotLine",
        "DashDotDotLine",
        "CustomDashLine"
    };

    QDebugStateSaver saver(dbg);
    dbg.nospace() << "QPen(" << p.width() << ',' << p.brush()
                  << ',' << PEN_STYLES[p.style()] << ',' << int(p.capStyle())
                  << ',' << int(p.joinStyle()) << ',' << p.dashPattern()
                  << ',' << p.dashOffset()
                  << ',' << p.miterLimit() << ')';
    return dbg;
}
#endif

/*!
    \fn DataPtr &QPen::data_ptr()
    \internal
*/

/*!
    \typedef QPen::DataPtr

    \internal
*/

QT_END_NAMESPACE

#undef QT_COMPILING_QPEN