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
|
/****************************************************************************
**
** 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 QGraphicsSceneBspTreeIndex
\brief The QGraphicsSceneBspTreeIndex class provides an implementation of
a BSP indexing algorithm for discovering items in QGraphicsScene.
\since 4.6
\ingroup graphicsview-api
\internal
QGraphicsSceneBspTreeIndex index use a BSP(Binary Space Partitioning)
implementation to discover items quickly. This implementation is
very efficient for static scene. It has a depth that you can set.
The depth directly affects performance and memory usage; the latter
growing exponentially with the depth of the tree. With an optimal tree
depth, the index can instantly determine the locality of items, even
for scenes with thousands or millions of items. This also greatly improves
rendering performance.
By default, the value is 0, in which case Qt will guess a reasonable
default depth based on the size, location and number of items in the
scene. If these parameters change frequently, however, you may experience
slowdowns as the index retunes the depth internally. You can avoid
potential slowdowns by fixating the tree depth through setting this
property.
The depth of the tree and the size of the scene rectangle decide the
granularity of the scene's partitioning. The size of each scene segment is
determined by the following algorithm:
The BSP tree has an optimal size when each segment contains between 0 and
10 items.
\sa QGraphicsScene, QGraphicsView, QGraphicsSceneIndex
*/
#include <QtCore/qglobal.h>
#ifndef QT_NO_GRAPHICSVIEW
#include <private/qgraphicsscene_p.h>
#include <private/qgraphicsscenebsptreeindex_p.h>
#include <private/qgraphicssceneindex_p.h>
#include <QtCore/qmath.h>
#include <QtCore/qdebug.h>
QT_BEGIN_NAMESPACE
static inline int intmaxlog(int n)
{
return (n > 0 ? qMax(qCeil(qLn(qreal(n)) / qLn(qreal(2))), 5) : 0);
}
/*!
Constructs a private scene bsp index.
*/
QGraphicsSceneBspTreeIndexPrivate::QGraphicsSceneBspTreeIndexPrivate(QGraphicsScene *scene)
: QGraphicsSceneIndexPrivate(scene),
bspTreeDepth(0),
indexTimerId(0),
restartIndexTimer(false),
regenerateIndex(true),
lastItemCount(0),
purgePending(false),
sortCacheEnabled(false),
updatingSortCache(false)
{
}
/*!
This method will update the BSP index by removing the items from the temporary
unindexed list and add them in the indexedItems list. This will also
update the growingItemsBoundingRect if needed. This will update the BSP
implementation as well.
\internal
*/
void QGraphicsSceneBspTreeIndexPrivate::_q_updateIndex()
{
Q_Q(QGraphicsSceneBspTreeIndex);
if (!indexTimerId)
return;
q->killTimer(indexTimerId);
indexTimerId = 0;
purgeRemovedItems();
// Add unindexedItems to indexedItems
for (int i = 0; i < unindexedItems.size(); ++i) {
if (QGraphicsItem *item = unindexedItems.at(i)) {
Q_ASSERT(!item->d_ptr->itemDiscovered);
if (!freeItemIndexes.isEmpty()) {
int freeIndex = freeItemIndexes.takeFirst();
item->d_func()->index = freeIndex;
indexedItems[freeIndex] = item;
} else {
item->d_func()->index = indexedItems.size();
indexedItems << item;
}
}
}
// Determine whether we should regenerate the BSP tree.
if (bspTreeDepth == 0) {
int oldDepth = intmaxlog(lastItemCount);
bspTreeDepth = intmaxlog(indexedItems.size());
static const int slack = 100;
if (bsp.leafCount() == 0 || (oldDepth != bspTreeDepth && qAbs(lastItemCount - indexedItems.size()) > slack)) {
// ### Crude algorithm.
regenerateIndex = true;
}
}
// Regenerate the tree.
if (regenerateIndex) {
regenerateIndex = false;
bsp.initialize(sceneRect, bspTreeDepth);
unindexedItems = indexedItems;
lastItemCount = indexedItems.size();
}
// Insert all unindexed items into the tree.
for (int i = 0; i < unindexedItems.size(); ++i) {
if (QGraphicsItem *item = unindexedItems.at(i)) {
if (item->d_ptr->itemIsUntransformable()) {
untransformableItems << item;
continue;
}
if (item->d_ptr->ancestorFlags & QGraphicsItemPrivate::AncestorClipsChildren)
continue;
bsp.insertItem(item, item->d_ptr->sceneEffectiveBoundingRect());
}
}
unindexedItems.clear();
}
/*!
\internal
Removes stale pointers from all data structures.
*/
void QGraphicsSceneBspTreeIndexPrivate::purgeRemovedItems()
{
if (!purgePending && removedItems.isEmpty())
return;
// Remove stale items from the BSP tree.
bsp.removeItems(removedItems);
// Purge this list.
removedItems.clear();
freeItemIndexes.clear();
for (int i = 0; i < indexedItems.size(); ++i) {
if (!indexedItems.at(i))
freeItemIndexes << i;
}
purgePending = false;
}
/*!
\internal
Starts or restarts the timer used for reindexing unindexed items.
*/
void QGraphicsSceneBspTreeIndexPrivate::startIndexTimer(int interval)
{
Q_Q(QGraphicsSceneBspTreeIndex);
if (indexTimerId) {
restartIndexTimer = true;
} else {
indexTimerId = q->startTimer(interval);
}
}
/*!
\internal
*/
void QGraphicsSceneBspTreeIndexPrivate::resetIndex()
{
purgeRemovedItems();
for (int i = 0; i < indexedItems.size(); ++i) {
if (QGraphicsItem *item = indexedItems.at(i)) {
item->d_ptr->index = -1;
Q_ASSERT(!item->d_ptr->itemDiscovered);
unindexedItems << item;
}
}
indexedItems.clear();
freeItemIndexes.clear();
untransformableItems.clear();
regenerateIndex = true;
startIndexTimer();
}
/*!
\internal
*/
void QGraphicsSceneBspTreeIndexPrivate::climbTree(QGraphicsItem *item, int *stackingOrder)
{
if (!item->d_ptr->children.isEmpty()) {
QList<QGraphicsItem *> childList = item->d_ptr->children;
qSort(childList.begin(), childList.end(), qt_closestLeaf);
for (int i = 0; i < childList.size(); ++i) {
QGraphicsItem *item = childList.at(i);
if (!(item->flags() & QGraphicsItem::ItemStacksBehindParent))
climbTree(childList.at(i), stackingOrder);
}
item->d_ptr->globalStackingOrder = (*stackingOrder)++;
for (int i = 0; i < childList.size(); ++i) {
QGraphicsItem *item = childList.at(i);
if (item->flags() & QGraphicsItem::ItemStacksBehindParent)
climbTree(childList.at(i), stackingOrder);
}
} else {
item->d_ptr->globalStackingOrder = (*stackingOrder)++;
}
}
/*!
\internal
*/
void QGraphicsSceneBspTreeIndexPrivate::_q_updateSortCache()
{
Q_Q(QGraphicsSceneBspTreeIndex);
_q_updateIndex();
if (!sortCacheEnabled || !updatingSortCache)
return;
updatingSortCache = false;
int stackingOrder = 0;
QList<QGraphicsItem *> topLevels;
const QList<QGraphicsItem *> items = q->items();
for (int i = 0; i < items.size(); ++i) {
QGraphicsItem *item = items.at(i);
if (item && !item->d_ptr->parent)
topLevels << item;
}
qSort(topLevels.begin(), topLevels.end(), qt_closestLeaf);
for (int i = 0; i < topLevels.size(); ++i)
climbTree(topLevels.at(i), &stackingOrder);
}
/*!
\internal
*/
void QGraphicsSceneBspTreeIndexPrivate::invalidateSortCache()
{
Q_Q(QGraphicsSceneBspTreeIndex);
if (!sortCacheEnabled || updatingSortCache)
return;
updatingSortCache = true;
QMetaObject::invokeMethod(q, "_q_updateSortCache", Qt::QueuedConnection);
}
void QGraphicsSceneBspTreeIndexPrivate::addItem(QGraphicsItem *item, bool recursive)
{
if (!item)
return;
// Prevent reusing a recently deleted pointer: purge all removed item from our lists.
purgeRemovedItems();
// Invalidate any sort caching; arrival of a new item means we need to resort.
// Update the scene's sort cache settings.
item->d_ptr->globalStackingOrder = -1;
invalidateSortCache();
// Indexing requires sceneBoundingRect(), but because \a item might
// not be completely constructed at this point, we need to store it in
// a temporary list and schedule an indexing for later.
if (item->d_ptr->index == -1) {
Q_ASSERT(!unindexedItems.contains(item));
unindexedItems << item;
startIndexTimer(0);
} else {
Q_ASSERT(indexedItems.contains(item));
qWarning("QGraphicsSceneBspTreeIndex::addItem: item has already been added to this BSP");
}
if (recursive) {
for (int i = 0; i < item->d_ptr->children.size(); ++i)
addItem(item->d_ptr->children.at(i), recursive);
}
}
void QGraphicsSceneBspTreeIndexPrivate::removeItem(QGraphicsItem *item, bool recursive,
bool moveToUnindexedItems)
{
if (!item)
return;
if (item->d_ptr->index != -1) {
Q_ASSERT(item->d_ptr->index < indexedItems.size());
Q_ASSERT(indexedItems.at(item->d_ptr->index) == item);
Q_ASSERT(!item->d_ptr->itemDiscovered);
freeItemIndexes << item->d_ptr->index;
indexedItems[item->d_ptr->index] = 0;
item->d_ptr->index = -1;
if (item->d_ptr->itemIsUntransformable()) {
untransformableItems.removeOne(item);
} else if (item->d_ptr->inDestructor) {
// Avoid virtual function calls from the destructor.
purgePending = true;
removedItems << item;
} else if (!(item->d_ptr->ancestorFlags & QGraphicsItemPrivate::AncestorClipsChildren)) {
bsp.removeItem(item, item->d_ptr->sceneEffectiveBoundingRect());
}
} else {
unindexedItems.removeOne(item);
}
invalidateSortCache(); // ### Only do this when removing from BSP?
Q_ASSERT(item->d_ptr->index == -1);
Q_ASSERT(!indexedItems.contains(item));
Q_ASSERT(!unindexedItems.contains(item));
Q_ASSERT(!untransformableItems.contains(item));
if (moveToUnindexedItems)
addItem(item);
if (recursive) {
for (int i = 0; i < item->d_ptr->children.size(); ++i)
removeItem(item->d_ptr->children.at(i), recursive, moveToUnindexedItems);
}
}
QList<QGraphicsItem *> QGraphicsSceneBspTreeIndexPrivate::estimateItems(const QRectF &rect, Qt::SortOrder order,
bool onlyTopLevelItems)
{
Q_Q(QGraphicsSceneBspTreeIndex);
if (onlyTopLevelItems && rect.isNull())
return q->QGraphicsSceneIndex::estimateTopLevelItems(rect, order);
purgeRemovedItems();
_q_updateSortCache();
Q_ASSERT(unindexedItems.isEmpty());
QList<QGraphicsItem *> rectItems = bsp.items(rect, onlyTopLevelItems);
if (onlyTopLevelItems) {
for (int i = 0; i < untransformableItems.size(); ++i) {
QGraphicsItem *item = untransformableItems.at(i);
if (!item->d_ptr->parent) {
rectItems << item;
} else {
item = item->topLevelItem();
if (!rectItems.contains(item))
rectItems << item;
}
}
} else {
rectItems += untransformableItems;
}
sortItems(&rectItems, order, sortCacheEnabled, onlyTopLevelItems);
return rectItems;
}
/*!
Sort a list of \a itemList in a specific \a order and use the cache if requested.
\internal
*/
void QGraphicsSceneBspTreeIndexPrivate::sortItems(QList<QGraphicsItem *> *itemList, Qt::SortOrder order,
bool sortCacheEnabled, bool onlyTopLevelItems)
{
if (order == Qt::SortOrder(-1))
return;
if (onlyTopLevelItems) {
if (order == Qt::DescendingOrder)
qSort(itemList->begin(), itemList->end(), qt_closestLeaf);
else if (order == Qt::AscendingOrder)
qSort(itemList->begin(), itemList->end(), qt_notclosestLeaf);
return;
}
if (sortCacheEnabled) {
if (order == Qt::DescendingOrder) {
qSort(itemList->begin(), itemList->end(), closestItemFirst_withCache);
} else if (order == Qt::AscendingOrder) {
qSort(itemList->begin(), itemList->end(), closestItemLast_withCache);
}
} else {
if (order == Qt::DescendingOrder) {
qSort(itemList->begin(), itemList->end(), qt_closestItemFirst);
} else if (order == Qt::AscendingOrder) {
qSort(itemList->begin(), itemList->end(), qt_closestItemLast);
}
}
}
/*!
Constructs a BSP scene index for the given \a scene.
*/
QGraphicsSceneBspTreeIndex::QGraphicsSceneBspTreeIndex(QGraphicsScene *scene)
: QGraphicsSceneIndex(*new QGraphicsSceneBspTreeIndexPrivate(scene), scene)
{
}
QGraphicsSceneBspTreeIndex::~QGraphicsSceneBspTreeIndex()
{
Q_D(QGraphicsSceneBspTreeIndex);
for (int i = 0; i < d->indexedItems.size(); ++i) {
// Ensure item bits are reset properly.
if (QGraphicsItem *item = d->indexedItems.at(i)) {
Q_ASSERT(!item->d_ptr->itemDiscovered);
item->d_ptr->index = -1;
}
}
}
/*!
\internal
Clear the all the BSP index.
*/
void QGraphicsSceneBspTreeIndex::clear()
{
Q_D(QGraphicsSceneBspTreeIndex);
d->bsp.clear();
d->lastItemCount = 0;
d->freeItemIndexes.clear();
for (int i = 0; i < d->indexedItems.size(); ++i) {
// Ensure item bits are reset properly.
if (QGraphicsItem *item = d->indexedItems.at(i)) {
Q_ASSERT(!item->d_ptr->itemDiscovered);
item->d_ptr->index = -1;
}
}
d->indexedItems.clear();
d->unindexedItems.clear();
d->untransformableItems.clear();
d->regenerateIndex = true;
}
/*!
Add the \a item into the BSP index.
*/
void QGraphicsSceneBspTreeIndex::addItem(QGraphicsItem *item)
{
Q_D(QGraphicsSceneBspTreeIndex);
d->addItem(item);
}
/*!
Remove the \a item from the BSP index.
*/
void QGraphicsSceneBspTreeIndex::removeItem(QGraphicsItem *item)
{
Q_D(QGraphicsSceneBspTreeIndex);
d->removeItem(item);
}
/*!
\internal
Update the BSP when the \a item 's bounding rect has changed.
*/
void QGraphicsSceneBspTreeIndex::prepareBoundingRectChange(const QGraphicsItem *item)
{
if (!item)
return;
if (item->d_ptr->index == -1 || item->d_ptr->itemIsUntransformable()
|| (item->d_ptr->ancestorFlags & QGraphicsItemPrivate::AncestorClipsChildren)) {
return; // Item is not in BSP tree; nothing to do.
}
Q_D(QGraphicsSceneBspTreeIndex);
QGraphicsItem *thatItem = const_cast<QGraphicsItem *>(item);
d->removeItem(thatItem, /*recursive=*/false, /*moveToUnindexedItems=*/true);
for (int i = 0; i < item->d_ptr->children.size(); ++i) // ### Do we really need this?
prepareBoundingRectChange(item->d_ptr->children.at(i));
}
/*!
Returns an estimation visible items that are either inside or
intersect with the specified \a rect and return a list sorted using \a order.
\a deviceTransform is the transformation apply to the view.
*/
QList<QGraphicsItem *> QGraphicsSceneBspTreeIndex::estimateItems(const QRectF &rect, Qt::SortOrder order) const
{
Q_D(const QGraphicsSceneBspTreeIndex);
return const_cast<QGraphicsSceneBspTreeIndexPrivate*>(d)->estimateItems(rect, order);
}
QList<QGraphicsItem *> QGraphicsSceneBspTreeIndex::estimateTopLevelItems(const QRectF &rect, Qt::SortOrder order) const
{
Q_D(const QGraphicsSceneBspTreeIndex);
return const_cast<QGraphicsSceneBspTreeIndexPrivate*>(d)->estimateItems(rect, order, /*onlyTopLevels=*/true);
}
/*!
\fn QList<QGraphicsItem *> QGraphicsSceneBspTreeIndex::items(Qt::SortOrder order = Qt::DescendingOrder) const;
Return all items in the BSP index and sort them using \a order.
*/
QList<QGraphicsItem *> QGraphicsSceneBspTreeIndex::items(Qt::SortOrder order) const
{
Q_D(const QGraphicsSceneBspTreeIndex);
const_cast<QGraphicsSceneBspTreeIndexPrivate*>(d)->purgeRemovedItems();
QList<QGraphicsItem *> itemList;
// If freeItemIndexes is empty, we know there are no holes in indexedItems and
// unindexedItems.
if (d->freeItemIndexes.isEmpty()) {
if (d->unindexedItems.isEmpty()) {
itemList = d->indexedItems;
} else {
itemList = d->indexedItems + d->unindexedItems;
}
} else {
// Rebuild the list of items to avoid holes. ### We could also just
// compress the item lists at this point.
foreach (QGraphicsItem *item, d->indexedItems + d->unindexedItems) {
if (item)
itemList << item;
}
}
if (order != -1) {
//We sort descending order
d->sortItems(&itemList, order, d->sortCacheEnabled);
}
return itemList;
}
/*!
\property QGraphicsSceneBspTreeIndex::bspTreeDepth
\brief the depth of the BSP index tree
\since 4.6
This value determines the depth of BSP tree. The depth
directly affects performance and memory usage; the latter
growing exponentially with the depth of the tree. With an optimal tree
depth, the index can instantly determine the locality of items, even
for scenes with thousands or millions of items. This also greatly improves
rendering performance.
By default, the value is 0, in which case Qt will guess a reasonable
default depth based on the size, location and number of items in the
scene. If these parameters change frequently, however, you may experience
slowdowns as the index retunes the depth internally. You can avoid
potential slowdowns by fixating the tree depth through setting this
property.
The depth of the tree and the size of the scene rectangle decide the
granularity of the scene's partitioning. The size of each scene segment is
determined by the following algorithm:
The BSP tree has an optimal size when each segment contains between 0 and
10 items.
*/
int QGraphicsSceneBspTreeIndex::bspTreeDepth()
{
Q_D(const QGraphicsSceneBspTreeIndex);
return d->bspTreeDepth;
}
void QGraphicsSceneBspTreeIndex::setBspTreeDepth(int depth)
{
Q_D(QGraphicsSceneBspTreeIndex);
if (d->bspTreeDepth == depth)
return;
d->bspTreeDepth = depth;
d->resetIndex();
}
/*!
\internal
This method react to the \a rect change of the scene and
reset the BSP tree index.
*/
void QGraphicsSceneBspTreeIndex::updateSceneRect(const QRectF &rect)
{
Q_D(QGraphicsSceneBspTreeIndex);
d->sceneRect = rect;
d->resetIndex();
}
/*!
\internal
This method react to the \a change of the \a item and use the \a value to
update the BSP tree if necessary.
*/
void QGraphicsSceneBspTreeIndex::itemChange(const QGraphicsItem *item, QGraphicsItem::GraphicsItemChange change, const QVariant &value)
{
Q_D(QGraphicsSceneBspTreeIndex);
switch (change) {
case QGraphicsItem::ItemFlagsChange: {
// Handle ItemIgnoresTransformations
bool ignoredTransform = item->d_ptr->flags & QGraphicsItem::ItemIgnoresTransformations;
bool willIgnoreTransform = value.toUInt() & QGraphicsItem::ItemIgnoresTransformations;
bool clipsChildren = item->d_ptr->flags & QGraphicsItem::ItemClipsChildrenToShape;
bool willClipChildren = value.toUInt() & QGraphicsItem::ItemClipsChildrenToShape;
if ((ignoredTransform != willIgnoreTransform) || (clipsChildren != willClipChildren)) {
QGraphicsItem *thatItem = const_cast<QGraphicsItem *>(item);
// Remove item and its descendants from the index and append
// them to the list of unindexed items. Then, when the index
// is updated, they will be put into the bsp-tree or the list
// of untransformable items.
d->removeItem(thatItem, /*recursive=*/true, /*moveToUnidexedItems=*/true);
}
break;
}
case QGraphicsItem::ItemZValueChange:
d->invalidateSortCache();
break;
case QGraphicsItem::ItemParentChange: {
d->invalidateSortCache();
// Handle ItemIgnoresTransformations
QGraphicsItem *newParent = qVariantValue<QGraphicsItem *>(value);
bool ignoredTransform = item->d_ptr->itemIsUntransformable();
bool willIgnoreTransform = (item->d_ptr->flags & QGraphicsItem::ItemIgnoresTransformations)
|| (newParent && newParent->d_ptr->itemIsUntransformable());
bool ancestorClippedChildren = item->d_ptr->ancestorFlags & QGraphicsItemPrivate::AncestorClipsChildren;
bool ancestorWillClipChildren = newParent
&& ((newParent->d_ptr->flags & QGraphicsItem::ItemClipsChildrenToShape)
|| (newParent->d_ptr->ancestorFlags & QGraphicsItemPrivate::AncestorClipsChildren));
if ((ignoredTransform != willIgnoreTransform) || (ancestorClippedChildren != ancestorWillClipChildren)) {
QGraphicsItem *thatItem = const_cast<QGraphicsItem *>(item);
// Remove item and its descendants from the index and append
// them to the list of unindexed items. Then, when the index
// is updated, they will be put into the bsp-tree or the list
// of untransformable items.
d->removeItem(thatItem, /*recursive=*/true, /*moveToUnidexedItems=*/true);
}
break;
}
default:
break;
}
return QGraphicsSceneIndex::itemChange(item, change, value);
}
/*!
\reimp
Used to catch the timer event.
\internal
*/
bool QGraphicsSceneBspTreeIndex::event(QEvent *event)
{
Q_D(QGraphicsSceneBspTreeIndex);
switch (event->type()) {
case QEvent::Timer:
if (d->indexTimerId && static_cast<QTimerEvent *>(event)->timerId() == d->indexTimerId) {
if (d->restartIndexTimer) {
d->restartIndexTimer = false;
} else {
// this call will kill the timer
d->_q_updateIndex();
}
}
// Fallthrough intended - support timers in subclasses.
default:
return QObject::event(event);
}
return true;
}
QT_END_NAMESPACE
#include "moc_qgraphicsscenebsptreeindex_p.cpp"
#endif // QT_NO_GRAPHICSVIEW
|