summaryrefslogtreecommitdiffstats
path: root/src/gui/effects/qgraphicseffect.cpp
blob: 239e29cd7faeb486e9be98e2d256b6131edad0ba (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
/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** 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 Technology Preview License Agreement accompanying
** this package.
**
** 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 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
**
**
**
**
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/

/*!
    \class QGraphicsEffect
    \brief The QGraphicsEffect class is the base class for all graphics
           effects.
    \since 4.6
    \ingroup multimedia
    \ingroup graphicsview-api

    Effects alter the appearance of elements by hooking into the rendering
    pipeline and operating between the source (e.g., a QGraphicsPixmapItem)
    and the destination device (e.g., QGraphicsView's viewport). Effects can be
    disabled by calling setEnabled(false). If effects are disabled, the source
    is rendered directly.

    To add a visual effect to a QGraphicsItem, for example, you can use one of
    the standard effects, or alternately, create your own effect by creating a
    subclass of QGraphicsEffect. The effect can then be installed on the item
    using QGraphicsItem::setGraphicsEffect().

    Qt provides the following standard effects:

    \list
    \o QGraphicsBlurEffect - blurs the item by a given radius
    \o QGraphicsDropShadowEffect - renders a dropshadow behind the item
    \o QGraphicsColorizeEffect - renders the item in shades of any given color
    \o QGraphicsOpacityEffect - renders the item with an opacity
    \endlist

    \table
    \row
    \o{2,1} \img graphicseffect-plain.png
    \row
    \o \img graphicseffect-blur.png
    \o \img graphicseffect-colorize.png
    \row
    \o \img graphicseffect-opacity.png
    \o \img graphicseffect-drop-shadow.png
    \endtable

    \img graphicseffect-widget.png

    For more information on how to use each effect, refer to the specific
    effect's documentation.

    To create your own custom effect, create a subclass of QGraphicsEffect (or
    any other existing effects) and reimplement the virtual function draw().
    This function is called whenever the effect needs to redraw. The draw()
    function takes the painter with which to draw as an argument. For more
    information, refer to the documenation for draw(). In the draw() function
    you can call sourcePixmap() to get a pixmap of the graphics effect source
    which you can then process.

    If your effect changes, use update() to request for a redraw. If your
    custom effect changes the bounding rectangle of the source, e.g., a radial
    glow effect may need to apply an extra margin, you can reimplement the
    virtual boundingRectFor() function, and call updateBoundingRect()
    to notify the framework whenever this rectangle changes. The virtual
    sourceChanged() function is called to notify the effects that
    the source has changed in some way - e.g., if the source is a
    QGraphicsRectItem and its rectangle parameters have changed.

    \sa QGraphicsItem::setGraphicsEffect(), QWidget::setGraphicsEffect()
*/

#include "qgraphicseffect_p.h"
#include "private/qgraphicsitem_p.h"

#include <QtGui/qgraphicsitem.h>

#include <QtGui/qimage.h>
#include <QtGui/qpainter.h>
#include <QtGui/qpaintengine.h>
#include <QtCore/qrect.h>
#include <QtCore/qdebug.h>
#include <private/qdrawhelper_p.h>

#ifndef QT_NO_GRAPHICSEFFECT
QT_BEGIN_NAMESPACE

/*!
    \internal
    \class QGraphicsEffectSource
    \brief The QGraphicsEffectSource class represents the source on which a
           QGraphicsEffect is installed on.

    When a QGraphicsEffect is installed on a QGraphicsItem, for example, this
    class will act as a wrapper around QGraphicsItem. Then, calling update() is
    effectively the same as calling QGraphicsItem::update().

    QGraphicsEffectSource also provides a pixmap() function which creates a
    pixmap with the source painted into it.

    \sa QGraphicsItem::setGraphicsEffect(), QWidget::setGraphicsEffect().
*/

/*!
    \internal
*/
QGraphicsEffectSource::QGraphicsEffectSource(QGraphicsEffectSourcePrivate &dd, QObject *parent)
    : QObject(dd, parent)
{}

/*!
    Destroys the effect source.
*/
QGraphicsEffectSource::~QGraphicsEffectSource()
{}

/*!
    Returns the bounding rectangle of the source mapped to the given \a system.

    \sa draw()
*/
QRectF QGraphicsEffectSource::boundingRect(Qt::CoordinateSystem system) const
{
    return d_func()->boundingRect(system);
}

/*!
    Returns the bounding rectangle of the source mapped to the given \a system.

    \sa draw()
*/
QRectF QGraphicsEffect::sourceBoundingRect(Qt::CoordinateSystem system) const
{
    Q_D(const QGraphicsEffect);
    if (d->source)
        return d->source->boundingRect(system);
    return QRectF();
}

/*!
    Returns a pointer to the item if this source is a QGraphicsItem; otherwise
    returns 0.

    \sa widget()
*/
const QGraphicsItem *QGraphicsEffectSource::graphicsItem() const
{
    return d_func()->graphicsItem();
}

/*!
    Returns a pointer to the widget if this source is a QWidget; otherwise
    returns 0.

    \sa graphicsItem()
*/
const QWidget *QGraphicsEffectSource::widget() const
{
    return d_func()->widget();
}

/*!
    Returns a pointer to the style options (used when drawing the source) if
    available; otherwise returns 0.

    \sa graphicsItem(), widget()
*/
const QStyleOption *QGraphicsEffectSource::styleOption() const
{
    return d_func()->styleOption();
}

/*!
    Draws the source using the given \a painter.

    This function should only be called from QGraphicsEffect::draw().

    \sa QGraphicsEffect::draw()
*/
void QGraphicsEffectSource::draw(QPainter *painter)
{
    Q_D(const QGraphicsEffectSource);

    QPixmap pm;
    if (QPixmapCache::find(d->m_cacheKey, &pm)) {
        QTransform restoreTransform;
        if (d->m_cachedSystem == Qt::DeviceCoordinates) {
            restoreTransform = painter->worldTransform();
            painter->setWorldTransform(QTransform());
        }

        painter->drawPixmap(d->m_cachedOffset, pm);

        if (d->m_cachedSystem == Qt::DeviceCoordinates)
            painter->setWorldTransform(restoreTransform);
    } else {
        d_func()->draw(painter);
    }
}

/*!
    Draws the source directly using the given \a painter.

    This function should only be called from QGraphicsEffect::draw().

    For example:

    \snippet doc/src/snippets/code/src_gui_effects_qgraphicseffect.cpp 0

    \sa QGraphicsEffect::draw()
*/
void QGraphicsEffect::drawSource(QPainter *painter)
{
    Q_D(const QGraphicsEffect);
    if (d->source)
        d->source->draw(painter);
}

/*!
    Schedules a redraw of the source. Call this function whenever the source
    needs to be redrawn.

    \sa QGraphicsEffect::updateBoundingRect(), QWidget::update(),
        QGraphicsItem::update(),
*/
void QGraphicsEffectSource::update()
{
    d_func()->update();
}

/*!
    Returns true if the source effectively is a pixmap, e.g., a
    QGraphicsPixmapItem.

    This function is useful for optimization purposes. For instance, there's no
    point in drawing the source in device coordinates to avoid pixmap scaling
    if this function returns true - the source pixmap will be scaled anyways.
*/
bool QGraphicsEffectSource::isPixmap() const
{
    return d_func()->isPixmap();
}

/*!
    Returns true if the source effectively is a pixmap, e.g., a
    QGraphicsPixmapItem.

    This function is useful for optimization purposes. For instance, there's no
    point in drawing the source in device coordinates to avoid pixmap scaling
    if this function returns true - the source pixmap will be scaled anyways.
*/
bool QGraphicsEffect::sourceIsPixmap() const
{
    return source() ? source()->isPixmap() : false;
}

/*!
    Returns a pixmap with the source painted into it.

    The \a system specifies which coordinate system to be used for the source.
    The optional \a offset parameter returns the offset where the pixmap should
    be painted at using the current painter.

    The \a mode determines how much of the effect the pixmap will contain.
    By default, the pixmap will contain the whole effect.

    The returned pixmap is bound to the current painter's device rectangle when
    \a system is Qt::DeviceCoordinates.

    \sa QGraphicsEffect::draw(), boundingRect()
*/
QPixmap QGraphicsEffectSource::pixmap(Qt::CoordinateSystem system, QPoint *offset, QGraphicsEffect::PixmapPadMode mode) const
{
    Q_D(const QGraphicsEffectSource);

    // Shortcut, no cache for childless pixmap items...
    const QGraphicsItem *item = graphicsItem();
    if (system == Qt::LogicalCoordinates && mode == QGraphicsEffect::NoPad && item && isPixmap()) {
        return ((QGraphicsPixmapItem *) item)->pixmap();
    }

    if (system == Qt::DeviceCoordinates && item
        && !static_cast<const QGraphicsItemEffectSourcePrivate *>(d_func())->info) {
        qWarning("QGraphicsEffectSource::pixmap: Not yet implemented, lacking device context");
        return QPixmap();
    }

    QPixmap pm;
    if (d->m_cachedSystem == system && d->m_cachedMode == mode)
        QPixmapCache::find(d->m_cacheKey, &pm);

    if (pm.isNull()) {
        pm = d->pixmap(system, &d->m_cachedOffset, mode);
        d->m_cachedSystem = system;
        d->m_cachedMode = mode;

        d->invalidateCache();
        d->m_cacheKey = QPixmapCache::insert(pm);
    }

    if (offset)
        *offset = d->m_cachedOffset;

    return pm;
}

/*!
    Returns a pixmap with the source painted into it.

    The \a system specifies which coordinate system to be used for the source.
    The optional \a offset parameter returns the offset where the pixmap should
    be painted at using the current painter. For control on how the pixmap is
    padded use the \a mode parameter.

    The returned pixmap is clipped to the current painter's device rectangle when
    \a system is Qt::DeviceCoordinates.

    \sa draw(), boundingRect()
*/
QPixmap QGraphicsEffect::sourcePixmap(Qt::CoordinateSystem system, QPoint *offset, QGraphicsEffect::PixmapPadMode mode) const
{
    Q_D(const QGraphicsEffect);
    if (d->source)
        return d->source->pixmap(system, offset, mode);
    return QPixmap();
}

QGraphicsEffectSourcePrivate::~QGraphicsEffectSourcePrivate()
{
    invalidateCache();
}

void QGraphicsEffectSourcePrivate::invalidateCache(bool effectRectChanged) const
{
    if (effectRectChanged && m_cachedMode != QGraphicsEffect::PadToEffectiveBoundingRect)
        return;
    QPixmapCache::remove(m_cacheKey);
}

/*!
    Constructs a new QGraphicsEffect instance having the
    specified \a parent.
*/
QGraphicsEffect::QGraphicsEffect(QObject *parent)
    : QObject(*new QGraphicsEffectPrivate, parent)
{
}

/*!
    \internal
*/
QGraphicsEffect::QGraphicsEffect(QGraphicsEffectPrivate &dd, QObject *parent)
    : QObject(dd, parent)
{
}

/*!
    Removes the effect from the source, and destroys the graphics effect.
*/
QGraphicsEffect::~QGraphicsEffect()
{
    Q_D(QGraphicsEffect);
    d->setGraphicsEffectSource(0);
}

/*!
    Returns the effective bounding rectangle for this effect, i.e., the
    bounding rectangle of the source, adjusted by any margins applied by
    the effect itself.

    \sa boundingRectFor(), updateBoundingRect()
*/
QRectF QGraphicsEffect::boundingRect() const
{
    Q_D(const QGraphicsEffect);
    if (d->source)
        return boundingRectFor(d->source->boundingRect());
    return QRectF();
}

/*!
    Returns the effective bounding rectangle for this effect, given the
    provided \a rect in the source's coordinate space. When writing
    you own custom effect, you must call updateBoundingRect() whenever any
    parameters are changed that may cause this this function to return a
    different value.

    \sa sourceBoundingRect()
*/
QRectF QGraphicsEffect::boundingRectFor(const QRectF &rect) const
{
    return rect;
}

/*!
    \property QGraphicsEffect::enabled
    \brief whether the effect is enabled or not.

    If an effect is disabled, the source will be rendered with as normal, with
    no interference from the effect. If the effect is enabled, the source will
    be rendered with the effect applied.

    This property is enabled by default.

    Using this property, you can disable certain effects on slow platforms, in
    order to ensure that the user interface is responsive.
*/
bool QGraphicsEffect::isEnabled() const
{
    Q_D(const QGraphicsEffect);
    return d->isEnabled;
}

void QGraphicsEffect::setEnabled(bool enable)
{
    Q_D(QGraphicsEffect);
    if (d->isEnabled == enable)
        return;

    d->isEnabled = enable;
    if (d->source) {
        d->source->d_func()->effectBoundingRectChanged();
        d->source->d_func()->invalidateCache();
    }
    emit enabledChanged(enable);
}

/*!
    \fn void QGraphicsEffect::enabledChanged(bool enabled)

    This signal is emitted whenever the effect is enabled or disabled.
    The \a enabled parameter holds the effects's new enabled state.

    \sa isEnabled()
*/

/*!
    Schedules a redraw of the source. Call this function whenever the source
    needs to be redrawn.

    This convenience function is equivalent to calling
    QGraphicsEffectSource::update().

    \sa updateBoundingRect(), QGraphicsEffectSource::update()
*/
void QGraphicsEffect::update()
{
    Q_D(QGraphicsEffect);
    if (d->source)
        d->source->update();
}

/*!
    \internal

    Returns a pointer to the source, which provides extra context information
    that can be useful for the effect.

    \sa draw()
*/
QGraphicsEffectSource *QGraphicsEffect::source() const
{
    Q_D(const QGraphicsEffect);
    return d->source;
}

/*!
    This function notifies the effect framework when the effect's bounding
    rectangle has changed. As a custom effect author, you must call this
    function whenever you change any parameters that will cause the virtual
    boundingRectFor() function to return a different value.

    This function will call update() if this is necessary.

    \sa boundingRectFor(), boundingRect(), sourceBoundingRect()
*/
void QGraphicsEffect::updateBoundingRect()
{
    Q_D(QGraphicsEffect);
    if (d->source) {
        d->source->d_func()->effectBoundingRectChanged();
        d->source->d_func()->invalidateCache(true);
    }
}

/*!
    \fn virtual void QGraphicsEffect::draw(QPainter *painter) = 0

    This pure virtual function draws the effect and is called whenever the
    source needs to be drawn.

    Reimplement this function in a QGraphicsEffect subclass to provide the
    effect's drawing implementation, using \a painter.

    For example:

    \snippet doc/src/snippets/code/src_gui_effects_qgraphicseffect.cpp 1

    This function should not be called explicitly by the user, since it is
    meant for reimplementation purposes only.
*/

/*!
    \enum QGraphicsEffect::ChangeFlag

    This enum describes what has changed in QGraphicsEffectSource.

    \value SourceAttached The effect is installed on a source.
    \value SourceDetached The effect is uninstalled on a source.
    \value SourceBoundingRectChanged The bounding rect of the source has
           changed.
    \value SourceInvalidated The visual appearance of the source has changed.
*/

/*!
    \enum QGraphicsEffect::PixmapPadMode

    This enum describes how the pixmap returned from sourcePixmap should be
    padded.

    \value NoPad The pixmap should not receive any additional
           padding.
    \value PadToTransparentBorder The pixmap should be padded
           to ensure it has a completely transparent border.
    \value PadToEffectiveBoundingRect The pixmap should be padded to
           match the effective bounding rectangle of the effect.
*/

/*!
    This virtual function is called by QGraphicsEffect to notify the effect
    that the source has changed. If the effect applies any cache, then this
    cache must be purged in order to reflect the new appearance of the source.

    The \a flags describes what has changed.
*/
void QGraphicsEffect::sourceChanged(ChangeFlags flags)
{
    Q_UNUSED(flags);
}

/*!
    \class QGraphicsColorizeEffect
    \brief The QGraphicsColorizeEffect class provides a colorize effect.
    \since 4.6

    A colorize effect renders the source with a tint of its color(). The color
    can be modified using the setColor() function.

    By default, the color is light blue (QColor(0, 0, 192)).

    \img graphicseffect-colorize.png

    \sa QGraphicsDropShadowEffect, QGraphicsBlurEffect, QGraphicsOpacityEffect
*/

/*!
    Constructs a new QGraphicsColorizeEffect instance.
    The \a parent parameter is passed to QGraphicsEffect's constructor.
*/
QGraphicsColorizeEffect::QGraphicsColorizeEffect(QObject *parent)
    : QGraphicsEffect(*new QGraphicsColorizeEffectPrivate, parent)
{
}

/*!
    Destroys the effect.
*/
QGraphicsColorizeEffect::~QGraphicsColorizeEffect()
{
}

/*!
    \property QGraphicsColorizeEffect::color
    \brief the color of the effect.

    By default, the color is light blue (QColor(0, 0, 192)).
*/
QColor QGraphicsColorizeEffect::color() const
{
    Q_D(const QGraphicsColorizeEffect);
    return d->filter->color();
}

void QGraphicsColorizeEffect::setColor(const QColor &color)
{
    Q_D(QGraphicsColorizeEffect);
    if (d->filter->color() == color)
        return;

    d->filter->setColor(color);
    update();
    emit colorChanged(color);
}

/*!
    \property QGraphicsColorizeEffect::strength
    \brief the strength of the effect.

    By default, the strength is 1.0.
    A strength 0.0 equals to no effect, while 1.0 means full colorization.
*/
qreal QGraphicsColorizeEffect::strength() const
{
    Q_D(const QGraphicsColorizeEffect);
    return d->filter->strength();
}

void QGraphicsColorizeEffect::setStrength(qreal strength)
{
    Q_D(QGraphicsColorizeEffect);
    if (qFuzzyCompare(d->filter->strength(), strength))
        return;

    d->filter->setStrength(strength);
    d->opaque = !qFuzzyIsNull(strength);
    update();
    emit strengthChanged(strength);
}

/*! \fn void QGraphicsColorizeEffect::strengthChanged(qreal strength)
  This signal is emitted whenever setStrength() changes the colorize
  strength property. \a strength contains the new strength value of
  the colorize effect.
 */

/*!
    \fn void QGraphicsColorizeEffect::colorChanged(const QColor &color)

    This signal is emitted whenever the effect's color changes.
    The \a color parameter holds the effect's new color.
*/

/*!
    \reimp
*/
void QGraphicsColorizeEffect::draw(QPainter *painter)
{
    Q_D(QGraphicsColorizeEffect);

    if (!d->opaque) {
        drawSource(painter);
        return;
    }

    QPoint offset;
    if (sourceIsPixmap()) {
        // No point in drawing in device coordinates (pixmap will be scaled anyways).
        const QPixmap pixmap = sourcePixmap(Qt::LogicalCoordinates, &offset, NoPad);
        d->filter->draw(painter, offset, pixmap);
        return;
    }

    // Draw pixmap in deviceCoordinates to avoid pixmap scaling.
    const QPixmap pixmap = sourcePixmap(Qt::DeviceCoordinates, &offset);
    QTransform restoreTransform = painter->worldTransform();
    painter->setWorldTransform(QTransform());
    d->filter->draw(painter, offset, pixmap);
    painter->setWorldTransform(restoreTransform);
}

/*!
    \class QGraphicsBlurEffect
    \brief The QGraphicsBlurEffect class provides a blur effect.
    \since 4.6

    A blur effect blurs the source. This effect is useful for reducing details,
    such as when the source loses focus and you want to draw attention to other
    elements. The level of detail can be modified using the setBlurRadius()
    function. Use setBlurHints() to choose the blur hints.

    By default, the blur radius is 5 pixels.

    \img graphicseffect-blur.png

    \sa QGraphicsDropShadowEffect, QGraphicsColorizeEffect, QGraphicsOpacityEffect
*/

/*!
    \enum QGraphicsBlurEffect::BlurHint
    \since 4.6

    This enum describes the possible hints that can be used to control how
    blur effects are applied. The hints might not have an effect in all the
    paint engines.

    \value PerformanceHint Indicates that rendering performance is the most important factor,
    at the potential cost of lower quality.

    \value QualityHint Indicates that rendering quality is the most important factor,
    at the potential cost of lower performance.

    \value AnimationHint Indicates that the blur radius is going to be animated, hinting
    that the implementation can keep a cache of blurred verisons of the source.
    Do not use this hint if the source is going to be dynamically changing.

    \sa blurHints(), setBlurHints()
*/


/*!
    Constructs a new QGraphicsBlurEffect instance.
    The \a parent parameter is passed to QGraphicsEffect's constructor.
*/
QGraphicsBlurEffect::QGraphicsBlurEffect(QObject *parent)
    : QGraphicsEffect(*new QGraphicsBlurEffectPrivate, parent)
{
    Q_D(QGraphicsBlurEffect);
    d->filter->setBlurHints(QGraphicsBlurEffect::PerformanceHint);
}

/*!
    Destroys the effect.
*/
QGraphicsBlurEffect::~QGraphicsBlurEffect()
{
}

/*!
    \property QGraphicsBlurEffect::blurRadius
    \brief the blur radius of the effect.

    Using a smaller radius results in a sharper appearance, whereas a bigger
    radius results in a more blurred appearance.

    By default, the blur radius is 5 pixels.
*/
qreal QGraphicsBlurEffect::blurRadius() const
{
    Q_D(const QGraphicsBlurEffect);
    return d->filter->radius();
}

void QGraphicsBlurEffect::setBlurRadius(qreal radius)
{
    Q_D(QGraphicsBlurEffect);
    if (qFuzzyCompare(d->filter->radius(), radius))
        return;

    d->filter->setRadius(radius);
    updateBoundingRect();
    emit blurRadiusChanged(radius);
}

/*!
    \fn void QGraphicsBlurEffect::blurRadiusChanged(qreal radius)

    This signal is emitted whenever the effect's blur radius changes.
    The \a radius parameter holds the effect's new blur radius.
*/

/*!
    \property QGraphicsBlurEffect::blurHints
    \brief the blur hint of the effect.

    Use the PerformanceHint hint to say that you want a faster blur,
    the QualityHint hint to say that you prefer a higher quality blur,
    or the AnimationHint when you want to animate the blur radius.

    By default, the blur hint is PerformanceHint.
*/
QGraphicsBlurEffect::BlurHints QGraphicsBlurEffect::blurHints() const
{
    Q_D(const QGraphicsBlurEffect);
    return d->filter->blurHints();
}

void QGraphicsBlurEffect::setBlurHints(QGraphicsBlurEffect::BlurHints hints)
{
    Q_D(QGraphicsBlurEffect);
    if (d->filter->blurHints() == hints)
        return;

    d->filter->setBlurHints(hints);
    emit blurHintsChanged(hints);
}

/*!
    \fn void QGraphicsBlurEffect::blurHintsChanged(QGraphicsBlurEffect::BlurHints hints)

    This signal is emitted whenever the effect's blur hints changes.
    The \a hints parameter holds the effect's new blur hints.
*/

/*!
    \reimp
*/
QRectF QGraphicsBlurEffect::boundingRectFor(const QRectF &rect) const
{
    Q_D(const QGraphicsBlurEffect);
    return d->filter->boundingRectFor(rect);
}

/*!
    \reimp
*/
void QGraphicsBlurEffect::draw(QPainter *painter)
{
    Q_D(QGraphicsBlurEffect);
    if (d->filter->radius() <= 0) {
        drawSource(painter);
        return;
    }

    PixmapPadMode mode = PadToEffectiveBoundingRect;
    if (painter->paintEngine()->type() == QPaintEngine::OpenGL2)
        mode = PadToTransparentBorder;

    // Draw pixmap in device coordinates to avoid pixmap scaling.
    QPoint offset;
    const QPixmap pixmap = sourcePixmap(Qt::DeviceCoordinates, &offset, mode);
    QTransform restoreTransform = painter->worldTransform();
    painter->setWorldTransform(QTransform());
    d->filter->draw(painter, offset, pixmap);
    painter->setWorldTransform(restoreTransform);
}

/*!
    \class QGraphicsDropShadowEffect
    \brief The QGraphicsDropShadowEffect class provides a drop shadow effect.
    \since 4.6

    A drop shadow effect renders the source with a drop shadow. The color of
    the drop shadow can be modified using the setColor() function. The drop
    shadow offset can be modified using the setOffset() function and the blur
    radius of the drop shadow can be changed with the setBlurRadius()
    function.

    By default, the drop shadow is a semi-transparent dark gray
    (QColor(63, 63, 63, 180)) shadow, blurred with a radius of 1 at an offset
    of 8 pixels towards the lower right.

    \img graphicseffect-drop-shadow.png

    \sa QGraphicsBlurEffect, QGraphicsColorizeEffect, QGraphicsOpacityEffect
*/

/*!
    Constructs a new QGraphicsDropShadowEffect instance.
    The \a parent parameter is passed to QGraphicsEffect's constructor.
*/
QGraphicsDropShadowEffect::QGraphicsDropShadowEffect(QObject *parent)
    : QGraphicsEffect(*new QGraphicsDropShadowEffectPrivate, parent)
{
}

/*!
    Destroys the effect.
*/
QGraphicsDropShadowEffect::~QGraphicsDropShadowEffect()
{
}

/*!
    \property QGraphicsDropShadowEffect::offset
    \brief the shadow offset in pixels.

    By default, the offset is 8 pixels towards the lower right.

    \sa xOffset(), yOffset(), blurRadius(), color()
*/
QPointF QGraphicsDropShadowEffect::offset() const
{
    Q_D(const QGraphicsDropShadowEffect);
    return d->filter->offset();
}

void QGraphicsDropShadowEffect::setOffset(const QPointF &offset)
{
    Q_D(QGraphicsDropShadowEffect);
    if (d->filter->offset() == offset)
        return;

    d->filter->setOffset(offset);
    updateBoundingRect();
    emit offsetChanged(offset);
}

/*!
    \property QGraphicsDropShadowEffect::xOffset
    \brief the horizontal shadow offset in pixels.

    By default, the horizontal shadow offset is 8 pixels.



    \sa yOffset(), offset()
*/

/*!
    \property QGraphicsDropShadowEffect::yOffset
    \brief the vertical shadow offset in pixels.

    By default, the vertical shadow offset is 8 pixels.

    \sa xOffset(), offset()
*/

/*!
    \fn void QGraphicsDropShadowEffect::offsetChanged(const QPointF &offset)

    This signal is emitted whenever the effect's shadow offset changes.
    The \a offset parameter holds the effect's new shadow offset.
*/

/*!
    \property QGraphicsDropShadowEffect::blurRadius
    \brief the blur radius in pixels of the drop shadow.

    Using a smaller radius results in a sharper shadow, whereas using a bigger
    radius results in a more blurred shadow.

    By default, the blur radius is 1 pixel.

    \sa color(), offset().
*/
qreal QGraphicsDropShadowEffect::blurRadius() const
{
    Q_D(const QGraphicsDropShadowEffect);
    return d->filter->blurRadius();
}

void QGraphicsDropShadowEffect::setBlurRadius(qreal blurRadius)
{
    Q_D(QGraphicsDropShadowEffect);
    if (qFuzzyCompare(d->filter->blurRadius(), blurRadius))
        return;

    d->filter->setBlurRadius(blurRadius);
    updateBoundingRect();
    emit blurRadiusChanged(blurRadius);
}

/*!
    \fn void QGraphicsDropShadowEffect::blurRadiusChanged(qreal blurRadius)

    This signal is emitted whenever the effect's blur radius changes.
    The \a blurRadius parameter holds the effect's new blur radius.
*/

/*!
    \property QGraphicsDropShadowEffect::color
    \brief the color of the drop shadow.

    By default, the drop color is a semi-transparent dark gray
    (QColor(63, 63, 63, 180)).

    \sa offset(), blurRadius()
*/
QColor QGraphicsDropShadowEffect::color() const
{
    Q_D(const QGraphicsDropShadowEffect);
    return d->filter->color();
}

void QGraphicsDropShadowEffect::setColor(const QColor &color)
{
    Q_D(QGraphicsDropShadowEffect);
    if (d->filter->color() == color)
        return;

    d->filter->setColor(color);
    update();
    emit colorChanged(color);
}

/*!
    \fn void QGraphicsDropShadowEffect::colorChanged(const QColor &color)

    This signal is emitted whenever the effect's color changes.
    The \a color parameter holds the effect's new color.
*/

/*!
    \reimp
*/
QRectF QGraphicsDropShadowEffect::boundingRectFor(const QRectF &rect) const
{
    Q_D(const QGraphicsDropShadowEffect);
    return d->filter->boundingRectFor(rect);
}

/*!
    \reimp
*/
void QGraphicsDropShadowEffect::draw(QPainter *painter)
{
    Q_D(QGraphicsDropShadowEffect);
    if (d->filter->blurRadius() <= 0 && d->filter->offset().isNull()) {
        drawSource(painter);
        return;
    }

    PixmapPadMode mode = PadToEffectiveBoundingRect;
    if (painter->paintEngine()->type() == QPaintEngine::OpenGL2)
        mode = PadToTransparentBorder;

    // Draw pixmap in device coordinates to avoid pixmap scaling.
    QPoint offset;
    const QPixmap pixmap = sourcePixmap(Qt::DeviceCoordinates, &offset, mode);
    QTransform restoreTransform = painter->worldTransform();
    painter->setWorldTransform(QTransform());
    d->filter->draw(painter, offset, pixmap);
    painter->setWorldTransform(restoreTransform);
}

/*!
    \class QGraphicsOpacityEffect
    \brief The QGraphicsOpacityEffect class provides an opacity effect.
    \since 4.6

    An opacity effect renders the source with an opacity. This effect is useful
    for making the source semi-transparent, similar to a fade-in/fade-out
    sequence. The opacity can be modified using the setOpacity() function.

    By default, the opacity is 0.7.

    \img graphicseffect-opacity.png

    \sa QGraphicsDropShadowEffect, QGraphicsBlurEffect, QGraphicsColorizeEffect
*/

/*!
    Constructs a new QGraphicsOpacityEffect instance.
    The \a parent parameter is passed to QGraphicsEffect's constructor.
*/
QGraphicsOpacityEffect::QGraphicsOpacityEffect(QObject *parent)
    : QGraphicsEffect(*new QGraphicsOpacityEffectPrivate, parent)
{
}

/*!
    Destroys the effect.
*/
QGraphicsOpacityEffect::~QGraphicsOpacityEffect()
{
}

/*!
    \property QGraphicsOpacityEffect::opacity
    \brief the opacity of the effect.

    The value should be in the range of 0.0 to 1.0, where 0.0 is
    fully transparent and 1.0 is fully opaque.

    By default, the opacity is 0.7.

    \sa setOpacityMask()
*/
qreal QGraphicsOpacityEffect::opacity() const
{
    Q_D(const QGraphicsOpacityEffect);
    return d->opacity;
}

void QGraphicsOpacityEffect::setOpacity(qreal opacity)
{
    Q_D(QGraphicsOpacityEffect);
    opacity = qBound(qreal(0.0), opacity, qreal(1.0));

    if (qFuzzyCompare(d->opacity, opacity))
        return;

    d->opacity = opacity;
    if ((d->isFullyTransparent = qFuzzyIsNull(d->opacity)))
        d->isFullyOpaque = 0;
    else
        d->isFullyOpaque = qFuzzyIsNull(d->opacity - 1);
    update();
    emit opacityChanged(opacity);
}

/*!
    \fn void QGraphicsOpacityEffect::opacityChanged(qreal opacity)

    This signal is emitted whenever the effect's opacity changes.
    The \a opacity parameter holds the effect's new opacity.
*/

/*!
    \property QGraphicsOpacityEffect::opacityMask
    \brief the opacity mask of the effect.

    An opacity mask allows you apply opacity to portions of an element.

    For example:

    \snippet doc/src/snippets/code/src_gui_effects_qgraphicseffect.cpp 2

    There is no opacity mask by default.

    \sa setOpacity()
*/
QBrush QGraphicsOpacityEffect::opacityMask() const
{
    Q_D(const QGraphicsOpacityEffect);
    return d->opacityMask;
}

void QGraphicsOpacityEffect::setOpacityMask(const QBrush &mask)
{
    Q_D(QGraphicsOpacityEffect);
    if (d->opacityMask == mask)
        return;

    d->opacityMask = mask;
    d->hasOpacityMask = (mask.style() != Qt::NoBrush);
    update();

    emit opacityMaskChanged(mask);
}

/*!
    \fn void QGraphicsOpacityEffect::opacityMaskChanged(const QBrush &mask)

    This signal is emitted whenever the effect's opacity mask changes.
    The \a mask parameter holds the effect's new opacity mask.
*/

/*!
    \reimp
*/
void QGraphicsOpacityEffect::draw(QPainter *painter)
{
    Q_D(QGraphicsOpacityEffect);

    // Transparent; nothing to draw.
    if (d->isFullyTransparent)
        return;

    // Opaque; draw directly without going through a pixmap.
    if (d->isFullyOpaque && !d->hasOpacityMask) {
        drawSource(painter);
        return;
    }

    QPoint offset;
    Qt::CoordinateSystem system = sourceIsPixmap() ? Qt::LogicalCoordinates : Qt::DeviceCoordinates;
    QPixmap pixmap = sourcePixmap(system, &offset, QGraphicsEffect::NoPad);
    if (pixmap.isNull())
        return;

    painter->save();
    painter->setOpacity(d->opacity);

    if (d->hasOpacityMask) {
        QPainter pixmapPainter(&pixmap);
        pixmapPainter.setRenderHints(painter->renderHints());
        pixmapPainter.setCompositionMode(QPainter::CompositionMode_DestinationIn);
        if (system == Qt::DeviceCoordinates) {
            QTransform worldTransform = painter->worldTransform();
            worldTransform *= QTransform::fromTranslate(-offset.x(), -offset.y());
            pixmapPainter.setWorldTransform(worldTransform);
            pixmapPainter.fillRect(sourceBoundingRect(), d->opacityMask);
        } else {
            pixmapPainter.translate(-offset);
            pixmapPainter.fillRect(pixmap.rect(), d->opacityMask);
        }
    }

    if (system == Qt::DeviceCoordinates)
        painter->setWorldTransform(QTransform());

    painter->drawPixmap(offset, pixmap);
    painter->restore();
}


QT_END_NAMESPACE

#endif //QT_NO_GRAPHICSEFFECT