summaryrefslogtreecommitdiffstats
path: root/src/qml/qml/qqmlcomponent.cpp
blob: 22a54d732e78a028f70bb7faccd49b4e93fe50e9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
/****************************************************************************
**
** Copyright (C) 2015 The Qt Company Ltd.
** Contact: http://www.qt.io/licensing/
**
** This file is part of the QtQml module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL21$
** 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 http://www.qt.io/terms-conditions. For further
** information use the contact form at http://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 2.1 or version 3 as published by the Free
** Software Foundation and appearing in the file LICENSE.LGPLv21 and
** LICENSE.LGPLv3 included in the packaging of this file. Please review the
** following information to ensure the GNU Lesser General Public License
** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** As a special exception, The Qt Company gives you certain additional
** rights. These rights are described in The Qt Company LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qqmlcomponent.h"
#include "qqmlcomponent_p.h"
#include "qqmlcomponentattached_p.h"

#include "qqmlcompiler_p.h"
#include "qqmlcontext_p.h"
#include "qqmlengine_p.h"
#include "qqmlvme_p.h"
#include "qqml.h"
#include "qqmlengine.h"
#include "qqmlbinding_p.h"
#include <private/qqmldebugconnector_p.h>
#include <private/qqmldebugserviceinterfaces_p.h>
#include "qqmlincubator.h"
#include "qqmlincubator_p.h"
#include <private/qqmljavascriptexpression_p.h>

#include <private/qv8engine_p.h>

#include <private/qv4functionobject_p.h>
#include <private/qv4script_p.h>
#include <private/qv4scopedvalue_p.h>
#include <private/qv4objectiterator_p.h>

#include <QStack>
#include <QStringList>
#include <QThreadStorage>
#include <QtCore/qdebug.h>
#include <qqmlinfo.h>
#include "qqmlmemoryprofiler_p.h"

namespace {
    QThreadStorage<int> creationDepth;
}

QT_BEGIN_NAMESPACE

class QQmlComponentExtension : public QV8Engine::Deletable
{
public:
    QQmlComponentExtension(QV4::ExecutionEngine *v4);
    virtual ~QQmlComponentExtension();

    QV4::PersistentValue incubationProto;
};
V4_DEFINE_EXTENSION(QQmlComponentExtension, componentExtension);

/*!
    \class QQmlComponent
    \since 5.0
    \inmodule QtQml

    \brief The QQmlComponent class encapsulates a QML component definition

    Components are reusable, encapsulated QML types with well-defined interfaces.

    A QQmlComponent instance can be created from a QML file.
    For example, if there is a \c main.qml file like this:

    \qml
    import QtQuick 2.0

    Item {
        width: 200
        height: 200
    }
    \endqml

    The following code loads this QML file as a component, creates an instance of
    this component using create(), and then queries the \l Item's \l {Item::}{width}
    value:

    \code
    QQmlEngine *engine = new QQmlEngine;
    QQmlComponent component(engine, QUrl::fromLocalFile("main.qml"));

    QObject *myObject = component.create();
    QQuickItem *item = qobject_cast<QQuickItem*>(myObject);
    int width = item->width();  // width = 200
    \endcode

    To create instances of a component in code where a QQmlEngine instance is
    not available, you can use \l qmlContext() or \l qmlEngine(). For example,
    in the scenario below, child items are being created within a QQuickItem
    subclass:

    \code
    void MyCppItem::init()
    {
        QQmlEngine *engine = qmlEngine(this);
        // Or:
        // QQmlEngine *engine = qmlContext(this)->engine();
        QQmlComponent component(engine, QUrl::fromLocalFile("MyItem.qml"));
        QQuickItem *childItem = qobject_cast<QQuickItem*>(component.create());
        childItem->setParentItem(this);
    }
    \endcode

    Note that these functions will return \c null when called inside the
    constructor of a QObject subclass, as the instance will not yet have
    a context nor engine.

    \section2 Network Components

    If the URL passed to QQmlComponent is a network resource, or if the QML document references a
    network resource, the QQmlComponent has to fetch the network data before it is able to create
    objects. In this case, the QQmlComponent will have a \l {QQmlComponent::Loading}{Loading}
    \l {QQmlComponent::status()}{status}. An application will have to wait until the component
    is \l {QQmlComponent::Ready}{Ready} before calling \l {QQmlComponent::create()}.

    The following example shows how to load a QML file from a network resource. After creating
    the QQmlComponent, it tests whether the component is loading. If it is, it connects to the
    QQmlComponent::statusChanged() signal and otherwise calls the \c {continueLoading()} method
    directly. Note that QQmlComponent::isLoading() may be false for a network component if the
    component has been cached and is ready immediately.

    \code
    MyApplication::MyApplication()
    {
        // ...
        component = new QQmlComponent(engine, QUrl("http://www.example.com/main.qml"));
        if (component->isLoading())
            QObject::connect(component, SIGNAL(statusChanged(QQmlComponent::Status)),
                             this, SLOT(continueLoading()));
        else
            continueLoading();
    }

    void MyApplication::continueLoading()
    {
        if (component->isError()) {
            qWarning() << component->errors();
        } else {
            QObject *myObject = component->create();
        }
    }
    \endcode

    Note that the \l {Qt Quick 1} version is named QDeclarativeComponent.
*/

/*!
    \qmltype Component
    \instantiates QQmlComponent
    \ingroup qml-utility-elements
    \inqmlmodule QtQml
    \brief Encapsulates a QML component definition

    Components are reusable, encapsulated QML types with well-defined interfaces.

    Components are often defined by \l {{QML Documents}}{component files} -
    that is, \c .qml files. The \e Component type essentially allows QML components
    to be defined inline, within a \l {QML Documents}{QML document}, rather than as a separate QML file.
    This may be useful for reusing a small component within a QML file, or for defining
    a component that logically belongs with other QML components within a file.

    For example, here is a component that is used by multiple \l Loader objects.
    It contains a single item, a \l Rectangle:

    \snippet qml/component.qml 0

    Notice that while a \l Rectangle by itself would be automatically
    rendered and displayed, this is not the case for the above rectangle
    because it is defined inside a \c Component. The component encapsulates the
    QML types within, as if they were defined in a separate QML
    file, and is not loaded until requested (in this case, by the
    two \l Loader objects). Because Component is not derived from Item, you cannot
    anchor anything to it.

    Defining a \c Component is similar to defining a \l {QML Documents}{QML document}.
    A QML document has a single top-level item that defines the behavior and
    properties of that component, and cannot define properties or behavior outside
    of that top-level item. In the same way, a \c Component definition contains a single
    top level item (which in the above example is a \l Rectangle) and cannot define any
    data outside of this item, with the exception of an \e id (which in the above example
    is \e redSquare).

    The \c Component type is commonly used to provide graphical components
    for views. For example, the ListView::delegate property requires a \c Component
    to specify how each list item is to be displayed.

    \c Component objects can also be created dynamically using
    \l{QtQml::Qt::createComponent()}{Qt.createComponent()}.

    \section2 Creation Context

    The creation context of a Component corresponds to the context where the Component was declared.
    This context is used as the parent context (creating a \l{qtqml-documents-scope.html#component-instance-hierarchy}{context hierarchy})
    when the component is instantiated by an object such as a ListView or a Loader.

    In the following example, \c comp1 is created within the root context of MyItem.qml, and any objects
    instantiated from this component will have access to the ids and properties within that context,
    such as \c internalSettings.color. When \c comp1 is used as a ListView delegate in another context
    (as in main.qml below), it will continue to have access to the properties of its creation context
    (which would otherwise be private to external users).

    \table
    \row
    \li MyItem.qml
    \li \snippet qml/component/MyItem.qml 0
    \row
    \li main.qml
    \li \snippet qml/component/main.qml 0
    \endtable
*/

/*!
    \qmlattachedsignal Component::completed()

    Emitted after the object has been instantiated. This can be used to
    execute script code at startup, once the full QML environment has been
    established.

    The corresponding handler is \c onCompleted. It can be declared on
    any object. The order of running the \c onCompleted handlers is
    undefined.

    \qml
    Rectangle {
        Component.onCompleted: console.log("Completed Running!")
        Rectangle {
            Component.onCompleted: console.log("Nested Completed Running!")
        }
    }
    \endqml
*/

/*!
    \qmlattachedsignal Component::destruction()

    Emitted as the object begins destruction. This can be used to undo
    work done in response to the \l {completed}{completed()} signal, or other
    imperative code in your application.

    The corresponding handler is \c onDestruction. It can be declared on
    any object. The order of running the \c onDestruction handlers is
    undefined.

    \qml
    Rectangle {
        Component.onDestruction: console.log("Destruction Beginning!")
        Rectangle {
            Component.onDestruction: console.log("Nested Destruction Beginning!")
        }
    }
    \endqml

    \sa {Qt QML}
*/

/*!
    \enum QQmlComponent::Status

    Specifies the loading status of the QQmlComponent.

    \value Null This QQmlComponent has no data. Call loadUrl() or setData() to add QML content.
    \value Ready This QQmlComponent is ready and create() may be called.
    \value Loading This QQmlComponent is loading network data.
    \value Error An error has occurred. Call errors() to retrieve a list of \l {QQmlError}{errors}.
*/

/*!
    \enum QQmlComponent::CompilationMode

    Specifies whether the QQmlComponent should load the component immediately, or asynchonously.

    \value PreferSynchronous Prefer loading/compiling the component immediately, blocking the thread.
    This is not always possible; for example, remote URLs will always load asynchronously.
    \value Asynchronous Load/compile the component in a background thread.
*/

void QQmlComponentPrivate::typeDataReady(QQmlTypeData *)
{
    Q_Q(QQmlComponent);

    Q_ASSERT(typeData);

    fromTypeData(typeData);
    typeData = 0;
    progress = 1.0;

    emit q->statusChanged(q->status());
    emit q->progressChanged(progress);
}

void QQmlComponentPrivate::typeDataProgress(QQmlTypeData *, qreal p)
{
    Q_Q(QQmlComponent);

    progress = p;

    emit q->progressChanged(p);
}

void QQmlComponentPrivate::fromTypeData(QQmlTypeData *data)
{
    url = data->finalUrl();
    QQmlCompiledData *c = data->compiledData();

    if (!c) {
        Q_ASSERT(data->isError());
        state.errors = data->errors();
    } else {
        cc = c;
        cc->addref();
    }

    data->release();
}

void QQmlComponentPrivate::clear()
{
    if (typeData) {
        typeData->unregisterCallback(this);
        typeData->release();
        typeData = 0;
    }

    if (cc) {
        cc->release();
        cc = 0;
    }
}

/*!
    \internal
*/
QQmlComponent::QQmlComponent(QObject *parent)
    : QObject(*(new QQmlComponentPrivate), parent)
{
}

/*!
    Destruct the QQmlComponent.
*/
QQmlComponent::~QQmlComponent()
{
    Q_D(QQmlComponent);

    if (d->state.completePending) {
        qWarning("QQmlComponent: Component destroyed while completion pending");
        d->completeCreate();
    }

    if (d->typeData) {
        d->typeData->unregisterCallback(d);
        d->typeData->release();
    }
    if (d->cc)
        d->cc->release();
}

/*!
    \qmlproperty enumeration Component::status
    This property holds the status of component loading. The status can be one of the
    following:
    \list
    \li Component.Null - no data is available for the component
    \li Component.Ready - the component has been loaded, and can be used to create instances.
    \li Component.Loading - the component is currently being loaded
    \li Component.Error - an error occurred while loading the component.
               Calling errorString() will provide a human-readable description of any errors.
    \endlist
 */

/*!
    \property QQmlComponent::status
    The component's current \l{QQmlComponent::Status} {status}.
 */
QQmlComponent::Status QQmlComponent::status() const
{
    Q_D(const QQmlComponent);

    if (d->typeData)
        return Loading;
    else if (!d->state.errors.isEmpty())
        return Error;
    else if (d->engine && d->cc)
        return Ready;
    else
        return Null;
}

/*!
    Returns true if status() == QQmlComponent::Null.
*/
bool QQmlComponent::isNull() const
{
    return status() == Null;
}

/*!
    Returns true if status() == QQmlComponent::Ready.
*/
bool QQmlComponent::isReady() const
{
    return status() == Ready;
}

/*!
    Returns true if status() == QQmlComponent::Error.
*/
bool QQmlComponent::isError() const
{
    return status() == Error;
}

/*!
    Returns true if status() == QQmlComponent::Loading.
*/
bool QQmlComponent::isLoading() const
{
    return status() == Loading;
}

/*!
    \qmlproperty real Component::progress
    The progress of loading the component, from 0.0 (nothing loaded)
    to 1.0 (finished).
*/

/*!
    \property QQmlComponent::progress
    The progress of loading the component, from 0.0 (nothing loaded)
    to 1.0 (finished).
*/
qreal QQmlComponent::progress() const
{
    Q_D(const QQmlComponent);
    return d->progress;
}

/*!
    \fn void QQmlComponent::progressChanged(qreal progress)

    Emitted whenever the component's loading progress changes. \a progress will be the
    current progress between 0.0 (nothing loaded) and 1.0 (finished).
*/

/*!
    \fn void QQmlComponent::statusChanged(QQmlComponent::Status status)

    Emitted whenever the component's status changes. \a status will be the
    new status.
*/

/*!
    Create a QQmlComponent with no data and give it the specified
    \a engine and \a parent. Set the data with setData().
*/
QQmlComponent::QQmlComponent(QQmlEngine *engine, QObject *parent)
    : QObject(*(new QQmlComponentPrivate), parent)
{
    Q_D(QQmlComponent);
    d->engine = engine;
}

/*!
    Create a QQmlComponent from the given \a url and give it the
    specified \a parent and \a engine.

    Ensure that the URL provided is full and correct, in particular, use
    \l QUrl::fromLocalFile() when loading a file from the local filesystem.

    \sa loadUrl()
*/
QQmlComponent::QQmlComponent(QQmlEngine *engine, const QUrl &url, QObject *parent)
: QObject(*(new QQmlComponentPrivate), parent)
{
    Q_D(QQmlComponent);
    d->engine = engine;
    d->loadUrl(url);
}

/*!
    Create a QQmlComponent from the given \a url and give it the
    specified \a parent and \a engine. If \a mode is \l Asynchronous,
    the component will be loaded and compiled asynchronously.

    Ensure that the URL provided is full and correct, in particular, use
    \l QUrl::fromLocalFile() when loading a file from the local filesystem.

    \sa loadUrl()
*/
QQmlComponent::QQmlComponent(QQmlEngine *engine, const QUrl &url, CompilationMode mode,
                             QObject *parent)
: QObject(*(new QQmlComponentPrivate), parent)
{
    Q_D(QQmlComponent);
    d->engine = engine;
    d->loadUrl(url, mode);
}

/*!
    Create a QQmlComponent from the given \a fileName and give it the specified
    \a parent and \a engine.

    \sa loadUrl()
*/
QQmlComponent::QQmlComponent(QQmlEngine *engine, const QString &fileName,
                             QObject *parent)
: QObject(*(new QQmlComponentPrivate), parent)
{
    Q_D(QQmlComponent);
    d->engine = engine;
    d->loadUrl(d->engine->baseUrl().resolved(QUrl::fromLocalFile(fileName)));
}

/*!
    Create a QQmlComponent from the given \a fileName and give it the specified
    \a parent and \a engine. If \a mode is \l Asynchronous,
    the component will be loaded and compiled asynchronously.

    \sa loadUrl()
*/
QQmlComponent::QQmlComponent(QQmlEngine *engine, const QString &fileName,
                             CompilationMode mode, QObject *parent)
: QObject(*(new QQmlComponentPrivate), parent)
{
    Q_D(QQmlComponent);
    d->engine = engine;
    d->loadUrl(d->engine->baseUrl().resolved(QUrl::fromLocalFile(fileName)), mode);
}

/*!
    \internal
*/
QQmlComponent::QQmlComponent(QQmlEngine *engine, QQmlCompiledData *cc, int start, QObject *parent)
    : QObject(*(new QQmlComponentPrivate), parent)
{
    Q_D(QQmlComponent);
    d->engine = engine;
    d->cc = cc;
    cc->addref();
    d->start = start;
    d->url = cc->url();
    d->progress = 1.0;
}

/*!
    Sets the QQmlComponent to use the given QML \a data. If \a url
    is provided, it is used to set the component name and to provide
    a base path for items resolved by this component.
*/
void QQmlComponent::setData(const QByteArray &data, const QUrl &url)
{
    Q_D(QQmlComponent);

    d->clear();

    d->url = url;

    QQmlTypeData *typeData = QQmlEnginePrivate::get(d->engine)->typeLoader.getType(data, url);

    if (typeData->isCompleteOrError()) {
        d->fromTypeData(typeData);
    } else {
        d->typeData = typeData;
        d->typeData->registerCallback(d);
    }

    d->progress = 1.0;
    emit statusChanged(status());
    emit progressChanged(d->progress);
}

/*!
Returns the QQmlContext the component was created in. This is only
valid for components created directly from QML.
*/
QQmlContext *QQmlComponent::creationContext() const
{
    Q_D(const QQmlComponent);
    if(d->creationContext)
        return d->creationContext->asQQmlContext();

    return qmlContext(this);
}

/*!
    Load the QQmlComponent from the provided \a url.

    Ensure that the URL provided is full and correct, in particular, use
    \l QUrl::fromLocalFile() when loading a file from the local filesystem.
*/
void QQmlComponent::loadUrl(const QUrl &url)
{
    Q_D(QQmlComponent);
    d->loadUrl(url);
}

/*!
    Load the QQmlComponent from the provided \a url.
    If \a mode is \l Asynchronous, the component will be loaded and compiled asynchronously.

    Ensure that the URL provided is full and correct, in particular, use
    \l QUrl::fromLocalFile() when loading a file from the local filesystem.
*/
void QQmlComponent::loadUrl(const QUrl &url, QQmlComponent::CompilationMode mode)
{
    Q_D(QQmlComponent);
    d->loadUrl(url, mode);
}

void QQmlComponentPrivate::loadUrl(const QUrl &newUrl, QQmlComponent::CompilationMode mode)
{
    Q_Q(QQmlComponent);
    clear();

    if ((newUrl.isRelative() && !newUrl.isEmpty())
    || newUrl.scheme() == QLatin1String("file")) // Workaround QTBUG-11929
        url = engine->baseUrl().resolved(newUrl);
    else
        url = newUrl;

    if (newUrl.isEmpty()) {
        QQmlError error;
        error.setDescription(QQmlComponent::tr("Invalid empty URL"));
        state.errors << error;
        return;
    }

    if (progress != 0.0) {
        progress = 0.0;
        emit q->progressChanged(progress);
    }

    QQmlTypeLoader::Mode loaderMode = (mode == QQmlComponent::Asynchronous)
            ? QQmlTypeLoader::Asynchronous
            : QQmlTypeLoader::PreferSynchronous;

    QQmlTypeData *data = QQmlEnginePrivate::get(engine)->typeLoader.getType(url, loaderMode);

    if (data->isCompleteOrError()) {
        fromTypeData(data);
        progress = 1.0;
    } else {
        typeData = data;
        typeData->registerCallback(this);
        progress = data->progress();
    }

    emit q->statusChanged(q->status());
    if (progress != 0.0)
        emit q->progressChanged(progress);
}

/*!
    Returns the list of errors that occurred during the last compile or create
    operation. An empty list is returned if isError() is not set.
*/
QList<QQmlError> QQmlComponent::errors() const
{
    Q_D(const QQmlComponent);
    if (isError())
        return d->state.errors;
    else
        return QList<QQmlError>();
}

/*!
    \qmlmethod string Component::errorString()

    Returns a human-readable description of any error.

    The string includes the file, location, and description of each error.
    If multiple errors are present, they are separated by a newline character.

    If no errors are present, an empty string is returned.
*/

/*!
    \internal
    errorString is only meant as a way to get the errors in script
*/
QString QQmlComponent::errorString() const
{
    Q_D(const QQmlComponent);
    QString ret;
    if(!isError())
        return ret;
    foreach(const QQmlError &e, d->state.errors) {
        ret += e.url().toString() + QLatin1Char(':') +
               QString::number(e.line()) + QLatin1Char(' ') +
               e.description() + QLatin1Char('\n');
    }
    return ret;
}

/*!
    \qmlproperty url Component::url
    The component URL. This is the URL that was used to construct the component.
*/

/*!
    \property QQmlComponent::url
    The component URL. This is the URL passed to either the constructor,
    or the loadUrl(), or setData() methods.
*/
QUrl QQmlComponent::url() const
{
    Q_D(const QQmlComponent);
    return d->url;
}

/*!
    \internal
*/
QQmlComponent::QQmlComponent(QQmlComponentPrivate &dd, QObject *parent)
    : QObject(dd, parent)
{
}

/*!
    Create an object instance from this component. Returns 0 if creation
    failed. \a context specifies the context within which to create the object
    instance.

    If \a context is 0 (the default), it will create the instance in the
    engine' s \l {QQmlEngine::rootContext()}{root context}.

    The ownership of the returned object instance is transferred to the caller.

    If the object being created from this component is a visual item, it must
    have a visual parent, which can be set by calling
    QQuickItem::setParentItem(). See \l {Concepts - Visual Parent in Qt Quick}
    for more details.

    \sa QQmlEngine::ObjectOwnership
*/
QObject *QQmlComponent::create(QQmlContext *context)
{
    Q_D(QQmlComponent);
    QML_MEMORY_SCOPE_URL(url());

    if (!context)
        context = d->engine->rootContext();

    QObject *rv = beginCreate(context);
    if (rv)
        completeCreate();
    return rv;
}

/*!
    This method provides advanced control over component instance creation.
    In general, programmers should use QQmlComponent::create() to create object
    instances.

    Create an object instance from this component. Returns 0 if creation
    failed. \a publicContext specifies the context within which to create the object
    instance.

    When QQmlComponent constructs an instance, it occurs in three steps:
    \list 1
    \li The object hierarchy is created, and constant values are assigned.
    \li Property bindings are evaluated for the first time.
    \li If applicable, QQmlParserStatus::componentComplete() is called on objects.
    \endlist
    QQmlComponent::beginCreate() differs from QQmlComponent::create() in that it
    only performs step 1. QQmlComponent::completeCreate() must be called to
    complete steps 2 and 3.

    This breaking point is sometimes useful when using attached properties to
    communicate information to an instantiated component, as it allows their
    initial values to be configured before property bindings take effect.

    The ownership of the returned object instance is transferred to the caller.

    \sa completeCreate(), QQmlEngine::ObjectOwnership
*/
QObject *QQmlComponent::beginCreate(QQmlContext *publicContext)
{
    Q_D(QQmlComponent);

    Q_ASSERT(publicContext);
    QQmlContextData *context = QQmlContextData::get(publicContext);

    return d->beginCreate(context);
}

QObject *
QQmlComponentPrivate::beginCreate(QQmlContextData *context)
{
    Q_Q(QQmlComponent);
    if (!context) {
        qWarning("QQmlComponent: Cannot create a component in a null context");
        return 0;
    }

    if (!context->isValid()) {
        qWarning("QQmlComponent: Cannot create a component in an invalid context");
        return 0;
    }

    if (context->engine != engine) {
        qWarning("QQmlComponent: Must create component in context from the same QQmlEngine");
        return 0;
    }

    if (state.completePending) {
        qWarning("QQmlComponent: Cannot create new component instance before completing the previous");
        return 0;
    }

    if (!q->isReady()) {
        qWarning("QQmlComponent: Component is not ready");
        return 0;
    }

    // Do not create infinite recursion in object creation
    static const int maxCreationDepth = 10;
    if (++creationDepth.localData() >= maxCreationDepth) {
        qWarning("QQmlComponent: Component creation is recursing - aborting");
        --creationDepth.localData();
        return 0;
    }
    Q_ASSERT(creationDepth.localData() >= 1);
    depthIncreased = true;

    QQmlEnginePrivate *enginePriv = QQmlEnginePrivate::get(engine);

    enginePriv->inProgressCreations++;
    state.errors.clear();
    state.completePending = true;

    enginePriv->referenceScarceResources();
    QObject *rv = 0;
    state.creator.reset(new QQmlObjectCreator(context, cc, creationContext));
    rv = state.creator->create(start);
    if (!rv)
        state.errors = state.creator->errors;
    enginePriv->dereferenceScarceResources();

    if (rv) {
        QQmlData *ddata = QQmlData::get(rv);
        Q_ASSERT(ddata);
        //top level objects should never get JS ownership.
        //if JS ownership is needed this needs to be explicitly undone (like in component.createObject())
        ddata->indestructible = true;
        ddata->explicitIndestructibleSet = true;
        ddata->rootObjectInCreation = false;
    } else {
        Q_ASSERT(creationDepth.localData() >= 1);
        --creationDepth.localData();
        depthIncreased = false;
    }

    QQmlEngineDebugService *service = QQmlDebugConnector::service<QQmlEngineDebugService>();
    if (service && rv) {
        if (!context->isInternal)
            context->asQQmlContextPrivate()->instances.append(rv);
        service->objectCreated(engine, rv);
    }

    return rv;
}

void QQmlComponentPrivate::beginDeferred(QQmlEnginePrivate *enginePriv,
                                                 QObject *object, ConstructionState *state)
{
    enginePriv->inProgressCreations++;
    state->errors.clear();
    state->completePending = true;

    QQmlData *ddata = QQmlData::get(object);
    Q_ASSERT(ddata->deferredData);
    QQmlData::DeferredData *deferredData = ddata->deferredData;
    QQmlContextData *creationContext = 0;
    state->creator.reset(new QQmlObjectCreator(deferredData->context->parent, deferredData->compiledData, creationContext));
    if (!state->creator->populateDeferredProperties(object))
        state->errors << state->creator->errors;
}

void QQmlComponentPrivate::complete(QQmlEnginePrivate *enginePriv, ConstructionState *state)
{
    if (state->completePending) {
        QQmlInstantiationInterrupt interrupt;
        state->creator->finalize(interrupt);

        state->completePending = false;

        enginePriv->inProgressCreations--;

        if (0 == enginePriv->inProgressCreations) {
            while (enginePriv->erroredBindings) {
                enginePriv->warning(enginePriv->erroredBindings);
                enginePriv->erroredBindings->removeError();
            }
        }
    }
}

/*!
    This method provides advanced control over component instance creation.
    In general, programmers should use QQmlComponent::create() to create a
    component.

    This function completes the component creation begun with QQmlComponent::beginCreate()
    and must be called afterwards.

    \sa beginCreate()
*/
void QQmlComponent::completeCreate()
{
    Q_D(QQmlComponent);

    d->completeCreate();
}

void QQmlComponentPrivate::completeCreate()
{
    if (state.completePending) {
        QQmlEnginePrivate *ep = QQmlEnginePrivate::get(engine);
        complete(ep, &state);
    }

    if (depthIncreased) {
        Q_ASSERT(creationDepth.localData() >= 1);
        --creationDepth.localData();
        depthIncreased = false;
    }
}

QQmlComponentAttached::QQmlComponentAttached(QObject *parent)
: QObject(parent), prev(0), next(0)
{
}

QQmlComponentAttached::~QQmlComponentAttached()
{
    if (prev) *prev = next;
    if (next) next->prev = prev;
    prev = 0;
    next = 0;
}

/*!
    \internal
*/
QQmlComponentAttached *QQmlComponent::qmlAttachedProperties(QObject *obj)
{
    QQmlComponentAttached *a = new QQmlComponentAttached(obj);

    QQmlEngine *engine = qmlEngine(obj);
    if (!engine)
        return a;

    QQmlEnginePrivate *p = QQmlEnginePrivate::get(engine);
    if (p->activeObjectCreator) { // XXX should only be allowed during begin
        a->add(p->activeObjectCreator->componentAttachment());
    } else {
        QQmlData *d = QQmlData::get(obj);
        Q_ASSERT(d);
        Q_ASSERT(d->context);
        a->add(&d->context->componentAttached);
    }

    return a;
}

/*!
    Create an object instance from this component using the provided
    \a incubator. \a context specifies the context within which to create the object
    instance.

    If \a context is 0 (the default), it will create the instance in the
    engine's \l {QQmlEngine::rootContext()}{root context}.

    \a forContext specifies a context that this object creation depends upon.
    If the \a forContext is being created asynchronously, and the
    \l QQmlIncubator::IncubationMode is \l QQmlIncubator::AsynchronousIfNested,
    this object will also be created asynchronously. If \a forContext is 0
    (the default), the \a context will be used for this decision.

    The created object and its creation status are available via the
    \a incubator.

    \sa QQmlIncubator
*/

void QQmlComponent::create(QQmlIncubator &incubator, QQmlContext *context,
                                   QQmlContext *forContext)
{
    Q_D(QQmlComponent);

    if (!context)
        context = d->engine->rootContext();

    QQmlContextData *contextData = QQmlContextData::get(context);
    QQmlContextData *forContextData = contextData;
    if (forContext) forContextData = QQmlContextData::get(forContext);

    if (!contextData->isValid()) {
        qWarning("QQmlComponent: Cannot create a component in an invalid context");
        return;
    }

    if (contextData->engine != d->engine) {
        qWarning("QQmlComponent: Must create component in context from the same QQmlEngine");
        return;
    }

    if (!isReady()) {
        qWarning("QQmlComponent: Component is not ready");
        return;
    }

    incubator.clear();
    QExplicitlySharedDataPointer<QQmlIncubatorPrivate> p(incubator.d);

    QQmlEnginePrivate *enginePriv = QQmlEnginePrivate::get(d->engine);

    p->compiledData = d->cc;
    p->compiledData->addref();
    p->creator.reset(new QQmlObjectCreator(contextData, d->cc, d->creationContext, p.data()));
    p->subComponentToCreate = d->start;

    enginePriv->incubate(incubator, forContextData);
}

class QQmlComponentIncubator;

namespace QV4 {

namespace Heap {

struct QmlIncubatorObject : Object {
    QmlIncubatorObject(QQmlIncubator::IncubationMode = QQmlIncubator::Asynchronous);
    QScopedPointer<QQmlComponentIncubator> incubator;
    QPointer<QObject> parent;
    QV4::Value valuemap;
    QV4::Value statusChanged;
};

}

struct QmlIncubatorObject : public QV4::Object
{
    V4_OBJECT2(QmlIncubatorObject, Object)
    V4_NEEDS_DESTROY

    static QV4::ReturnedValue method_get_statusChanged(QV4::CallContext *ctx);
    static QV4::ReturnedValue method_set_statusChanged(QV4::CallContext *ctx);
    static QV4::ReturnedValue method_get_status(QV4::CallContext *ctx);
    static QV4::ReturnedValue method_get_object(QV4::CallContext *ctx);
    static QV4::ReturnedValue method_forceCompletion(QV4::CallContext *ctx);

    static void markObjects(QV4::Heap::Base *that, QV4::ExecutionEngine *e);

    void statusChanged(QQmlIncubator::Status);
    void setInitialState(QObject *);
};

}

DEFINE_OBJECT_VTABLE(QV4::QmlIncubatorObject);

class QQmlComponentIncubator : public QQmlIncubator
{
public:
    QQmlComponentIncubator(QV4::Heap::QmlIncubatorObject *inc, IncubationMode mode)
        : QQmlIncubator(mode)
        , incubatorObject(inc)
    {}

    virtual void statusChanged(Status s) {
        QV4::Scope scope(incubatorObject->internalClass->engine);
        QV4::Scoped<QV4::QmlIncubatorObject> i(scope, incubatorObject);
        i->statusChanged(s);
    }

    virtual void setInitialState(QObject *o) {
        QV4::Scope scope(incubatorObject->internalClass->engine);
        QV4::Scoped<QV4::QmlIncubatorObject> i(scope, incubatorObject);
        i->setInitialState(o);
    }

    QV4::Heap::QmlIncubatorObject *incubatorObject;
};


static void QQmlComponent_setQmlParent(QObject *me, QObject *parent)
{
    if (parent) {
        me->setParent(parent);
        typedef QQmlPrivate::AutoParentFunction APF;
        QList<APF> functions = QQmlMetaType::parentFunctions();

        bool needParent = false;
        for (int ii = 0; ii < functions.count(); ++ii) {
            QQmlPrivate::AutoParentResult res = functions.at(ii)(me, parent);
            if (res == QQmlPrivate::Parented) {
                needParent = false;
                break;
            } else if (res == QQmlPrivate::IncompatibleParent) {
                needParent = true;
            }
        }
        if (needParent)
            qWarning("QQmlComponent: Created graphical object was not "
                     "placed in the graphics scene.");
    }
}

/*!
    \qmlmethod object Component::createObject(Item parent, object properties)

    Creates and returns an object instance of this component that will have
    the given \a parent and \a properties. The \a properties argument is optional.
    Returns null if object creation fails.

    The object will be created in the same context as the one in which the component
    was created. This function will always return null when called on components
    which were not created in QML.

    If you wish to create an object without setting a parent, specify \c null for
    the \a parent value. Note that if the returned object is to be displayed, you
    must provide a valid \a parent value or set the returned object's \l{Item::parent}{parent}
    property, otherwise the object will not be visible.

    If a \a parent is not provided to createObject(), a reference to the returned object must be held so that
    it is not destroyed by the garbage collector. This is true regardless of whether \l{Item::parent} is set afterwards,
    because setting the Item parent does not change object ownership. Only the graphical parent is changed.

    As of \c {QtQuick 1.1}, this method accepts an optional \a properties argument that specifies a
    map of initial property values for the created object. These values are applied before the object
    creation is finalized. This is more efficient than setting property values after object creation,
    particularly where large sets of property values are defined, and also allows property bindings
    to be set up (using \l{Qt::binding}{Qt.binding}) before the object is created.

    The \a properties argument is specified as a map of property-value items. For example, the code
    below creates an object with initial \c x and \c y values of 100 and 100, respectively:

    \js
        var component = Qt.createComponent("Button.qml");
        if (component.status == Component.Ready)
            component.createObject(parent, {"x": 100, "y": 100});
    \endjs

    Dynamically created instances can be deleted with the \c destroy() method.
    See \l {Dynamic QML Object Creation from JavaScript} for more information.

    \sa incubateObject()
*/


static void setInitialProperties(QV4::ExecutionEngine *engine, const QV4::Value &o, const QV4::Value &v)
{
    QV4::Scope scope(engine);
    QV4::ScopedObject object(scope);
    QV4::ScopedObject valueMap(scope, v);
    QV4::ObjectIterator it(scope, valueMap, QV4::ObjectIterator::EnumerableOnly|QV4::ObjectIterator::WithProtoChain);
    QV4::ScopedString name(scope);
    QV4::ScopedValue val(scope);
    if (engine->hasException)
        return;

    while (1) {
        name = it.nextPropertyNameAsString(val);
        if (!name)
            break;
        object = o;
        const QStringList properties = name->toQString().split(QLatin1Char('.'));
        for (int i = 0; i < properties.length() - 1; ++i) {
            name = engine->newString(properties.at(i));
            object = object->get(name);
            if (engine->hasException || !object) {
                break;
            }
        }
        if (engine->hasException || !object) {
            engine->hasException = false;
            continue;
        }
        name = engine->newString(properties.last());
        object->put(name, val);
        if (engine->hasException) {
            engine->hasException = false;
            continue;
        }
    }

    engine->hasException = false;
}

/*!
    \internal
*/
void QQmlComponent::createObject(QQmlV4Function *args)
{
    Q_D(QQmlComponent);
    Q_ASSERT(d->engine);
    Q_ASSERT(args);

    QObject *parent = 0;
    QV4::ExecutionEngine *v4 = args->v4engine();
    QV4::Scope scope(v4);
    QV4::ScopedValue valuemap(scope, QV4::Primitive::undefinedValue());

    if (args->length() >= 1) {
        QV4::Scoped<QV4::QObjectWrapper> qobjectWrapper(scope, (*args)[0]);
        if (qobjectWrapper)
            parent = qobjectWrapper->object();
    }

    if (args->length() >= 2) {
        QV4::ScopedValue v(scope, (*args)[1]);
        if (!v->as<QV4::Object>() || v->as<QV4::ArrayObject>()) {
            qmlInfo(this) << tr("createObject: value is not an object");
            args->setReturnValue(QV4::Encode::null());
            return;
        }
        valuemap = v;
    }

    QQmlContext *ctxt = creationContext();
    if (!ctxt) ctxt = d->engine->rootContext();

    QObject *rv = beginCreate(ctxt);

    if (!rv) {
        args->setReturnValue(QV4::Encode::null());
        return;
    }

    QQmlComponent_setQmlParent(rv, parent);

    QV4::ScopedValue object(scope, QV4::QObjectWrapper::wrap(v4, rv));
    Q_ASSERT(object->isObject());

    if (!valuemap->isUndefined())
        setInitialProperties(v4, object, valuemap);

    d->completeCreate();

    Q_ASSERT(QQmlData::get(rv));
    QQmlData::get(rv)->explicitIndestructibleSet = false;
    QQmlData::get(rv)->indestructible = false;

    args->setReturnValue(object->asReturnedValue());
}

/*!
    \qmlmethod object Component::incubateObject(Item parent, object properties, enumeration mode)

    Creates an incubator for an instance of this component. Incubators allow new component
    instances to be instantiated asynchronously and do not cause freezes in the UI.

    The \a parent argument specifies the parent the created instance will have. Omitting the
    parameter or passing null will create an object with no parent. In this case, a reference
    to the created object must be held so that it is not destroyed by the garbage collector.

    The \a properties argument is specified as a map of property-value items which will be
    set on the created object during its construction. \a mode may be Qt.Synchronous or
    Qt.Asynchronous, and controls whether the instance is created synchronously or asynchronously.
    The default is asynchronous. In some circumstances, even if Qt.Synchronous is specified,
    the incubator may create the object asynchronously. This happens if the component calling
    incubateObject() is itself being created asynchronously.

    All three arguments are optional.

    If successful, the method returns an incubator, otherwise null. The incubator has the following
    properties:

    \list
    \li status The status of the incubator. Valid values are Component.Ready, Component.Loading and
       Component.Error.
    \li object The created object instance. Will only be available once the incubator is in the
       Ready status.
    \li onStatusChanged Specifies a callback function to be invoked when the status changes. The
       status is passed as a parameter to the callback.
    \li forceCompletion() Call to complete incubation synchronously.
    \endlist

    The following example demonstrates how to use an incubator:

    \js
        var component = Qt.createComponent("Button.qml");

        var incubator = component.incubateObject(parent, { x: 10, y: 10 });
        if (incubator.status != Component.Ready) {
            incubator.onStatusChanged = function(status) {
                if (status == Component.Ready) {
                    print ("Object", incubator.object, "is now ready!");
                }
            }
        } else {
            print ("Object", incubator.object, "is ready immediately!");
        }
    \endjs

    Dynamically created instances can be deleted with the \c destroy() method.
    See \l {Dynamic QML Object Creation from JavaScript} for more information.

    \sa createObject()
*/

/*!
    \internal
*/
void QQmlComponent::incubateObject(QQmlV4Function *args)
{
    Q_D(QQmlComponent);
    Q_ASSERT(d->engine);
    Q_UNUSED(d);
    Q_ASSERT(args);
    QV4::ExecutionEngine *v4 = args->v4engine();
    QV4::Scope scope(v4);

    QObject *parent = 0;
    QV4::ScopedValue valuemap(scope, QV4::Primitive::undefinedValue());
    QQmlIncubator::IncubationMode mode = QQmlIncubator::Asynchronous;

    if (args->length() >= 1) {
        QV4::Scoped<QV4::QObjectWrapper> qobjectWrapper(scope, (*args)[0]);
        if (qobjectWrapper)
            parent = qobjectWrapper->object();
    }

    if (args->length() >= 2) {
        QV4::ScopedValue v(scope, (*args)[1]);
        if (v->isNull()) {
        } else if (!v->as<QV4::Object>() || v->as<QV4::ArrayObject>()) {
            qmlInfo(this) << tr("createObject: value is not an object");
            args->setReturnValue(QV4::Encode::null());
            return;
        } else {
            valuemap = v;
        }
    }

    if (args->length() >= 3) {
        QV4::ScopedValue val(scope, (*args)[2]);
        quint32 v = val->toUInt32();
        if (v == 0)
            mode = QQmlIncubator::Asynchronous;
        else if (v == 1)
            mode = QQmlIncubator::AsynchronousIfNested;
    }

    QQmlComponentExtension *e = componentExtension(args->v4engine());

    QV4::Scoped<QV4::QmlIncubatorObject> r(scope, v4->memoryManager->allocObject<QV4::QmlIncubatorObject>(mode));
    QV4::ScopedObject p(scope, e->incubationProto.value());
    r->setPrototype(p);

    if (!valuemap->isUndefined())
        r->d()->valuemap = valuemap;
    r->d()->parent = parent;

    QQmlIncubator *incubator = r->d()->incubator.data();
    create(*incubator, creationContext());

    if (incubator->status() == QQmlIncubator::Null) {
        args->setReturnValue(QV4::Encode::null());
    } else {
        args->setReturnValue(r.asReturnedValue());
    }
}

// XXX used by QSGLoader
void QQmlComponentPrivate::initializeObjectWithInitialProperties(const QV4::Value &valuemap, QObject *toCreate)
{
    QQmlEnginePrivate *ep = QQmlEnginePrivate::get(engine);
    QV4::ExecutionEngine *v4engine = QV8Engine::getV4(ep->v8engine());
    QV4::Scope scope(v4engine);

    QV4::ScopedValue object(scope, QV4::QObjectWrapper::wrap(v4engine, toCreate));
    Q_ASSERT(object->as<QV4::Object>());

    if (!valuemap.isUndefined())
        setInitialProperties(v4engine, object, valuemap);
}

QQmlComponentExtension::QQmlComponentExtension(QV4::ExecutionEngine *v4)
{
    QV4::Scope scope(v4);
    QV4::ScopedObject proto(scope, v4->newObject());
    proto->defineAccessorProperty(QStringLiteral("onStatusChanged"),
                                  QV4::QmlIncubatorObject::method_get_statusChanged, QV4::QmlIncubatorObject::method_set_statusChanged);
    proto->defineAccessorProperty(QStringLiteral("status"), QV4::QmlIncubatorObject::method_get_status, 0);
    proto->defineAccessorProperty(QStringLiteral("object"), QV4::QmlIncubatorObject::method_get_object, 0);
    proto->defineDefaultProperty(QStringLiteral("forceCompletion"), QV4::QmlIncubatorObject::method_forceCompletion);

    incubationProto.set(v4, proto);
}

QV4::ReturnedValue QV4::QmlIncubatorObject::method_get_object(QV4::CallContext *ctx)
{
    QV4::Scope scope(ctx);
    QV4::Scoped<QmlIncubatorObject> o(scope, ctx->thisObject().as<QmlIncubatorObject>());
    if (!o)
        return ctx->engine()->throwTypeError();

    return QV4::QObjectWrapper::wrap(ctx->d()->engine, o->d()->incubator->object());
}

QV4::ReturnedValue QV4::QmlIncubatorObject::method_forceCompletion(QV4::CallContext *ctx)
{
    QV4::Scope scope(ctx);
    QV4::Scoped<QmlIncubatorObject> o(scope, ctx->thisObject().as<QmlIncubatorObject>());
    if (!o)
        return ctx->engine()->throwTypeError();

    o->d()->incubator->forceCompletion();

    return QV4::Encode::undefined();
}

QV4::ReturnedValue QV4::QmlIncubatorObject::method_get_status(QV4::CallContext *ctx)
{
    QV4::Scope scope(ctx);
    QV4::Scoped<QmlIncubatorObject> o(scope, ctx->thisObject().as<QmlIncubatorObject>());
    if (!o)
        return ctx->engine()->throwTypeError();

    return QV4::Encode(o->d()->incubator->status());
}

QV4::ReturnedValue QV4::QmlIncubatorObject::method_get_statusChanged(QV4::CallContext *ctx)
{
    QV4::Scope scope(ctx);
    QV4::Scoped<QmlIncubatorObject> o(scope, ctx->thisObject().as<QmlIncubatorObject>());
    if (!o)
        return ctx->engine()->throwTypeError();

    return o->d()->statusChanged.asReturnedValue();
}

QV4::ReturnedValue QV4::QmlIncubatorObject::method_set_statusChanged(QV4::CallContext *ctx)
{
    QV4::Scope scope(ctx);
    QV4::Scoped<QmlIncubatorObject> o(scope, ctx->thisObject().as<QmlIncubatorObject>());
    if (!o || ctx->argc() < 1)
        return ctx->engine()->throwTypeError();


    o->d()->statusChanged = ctx->args()[0];
    return QV4::Encode::undefined();
}

QQmlComponentExtension::~QQmlComponentExtension()
{
}

QV4::Heap::QmlIncubatorObject::QmlIncubatorObject(QQmlIncubator::IncubationMode m)
    : valuemap(QV4::Primitive::undefinedValue())
    , statusChanged(QV4::Primitive::undefinedValue())
{
    incubator.reset(new QQmlComponentIncubator(this, m));
}

void QV4::QmlIncubatorObject::setInitialState(QObject *o)
{
    QQmlComponent_setQmlParent(o, d()->parent);

    if (!d()->valuemap.isUndefined()) {
        QV4::ExecutionEngine *v4 = engine();
        QV4::Scope scope(v4);
        QV4::ScopedObject obj(scope, QV4::QObjectWrapper::wrap(v4, o));
        setInitialProperties(v4, obj, d()->valuemap);
    }
}

void QV4::QmlIncubatorObject::markObjects(QV4::Heap::Base *that, QV4::ExecutionEngine *e)
{
    QmlIncubatorObject::Data *o = static_cast<QmlIncubatorObject::Data *>(that);
    o->valuemap.mark(e);
    o->statusChanged.mark(e);
    Object::markObjects(that, e);
}

void QV4::QmlIncubatorObject::statusChanged(QQmlIncubator::Status s)
{
    QV4::Scope scope(engine());
    // hold the incubated object in a scoped value to prevent it's destruction before this method returns
    QV4::ScopedObject incubatedObject(scope, QV4::QObjectWrapper::wrap(scope.engine, d()->incubator->object()));

    if (s == QQmlIncubator::Ready) {
        Q_ASSERT(QQmlData::get(d()->incubator->object()));
        QQmlData::get(d()->incubator->object())->explicitIndestructibleSet = false;
        QQmlData::get(d()->incubator->object())->indestructible = false;
    }

    QV4::ScopedFunctionObject f(scope, d()->statusChanged);
    if (f) {
        QV4::ScopedCallData callData(scope, 1);
        callData->thisObject = this;
        callData->args[0] = QV4::Primitive::fromUInt32(s);
        f->call(callData);
        if (scope.hasException()) {
            QQmlError error = scope.engine->catchExceptionAsQmlError();
            QQmlEnginePrivate::warning(QQmlEnginePrivate::get(scope.engine->qmlEngine()), error);
        }
    }
}

#undef INITIALPROPERTIES_SOURCE

QT_END_NAMESPACE