summaryrefslogtreecommitdiffstats
path: root/layout/base/nsPresContext.h
blob: d8f876291c67450b8b0b4196df6bf74299e8963d (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
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/* a presentation of a document, part 1 */

#ifndef nsPresContext_h___
#define nsPresContext_h___

#include "mozilla/Attributes.h"
#include "mozilla/WeakPtr.h"
#include "nsColor.h"
#include "nsCoord.h"
#include "nsCOMPtr.h"
#include "nsIPresShell.h"
#include "nsRect.h"
#include "nsFont.h"
#include "gfxFontConstants.h"
#include "nsIAtom.h"
#include "nsIObserver.h"
#include "nsITimer.h"
#include "nsCRT.h"
#include "nsIWidgetListener.h"
#include "FramePropertyTable.h"
#include "nsGkAtoms.h"
#include "nsCycleCollectionParticipant.h"
#include "nsChangeHint.h"
#include <algorithm>
// This also pulls in gfxTypes.h, which we cannot include directly.
#include "gfxRect.h"
#include "nsTArray.h"
#include "nsAutoPtr.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/TimeStamp.h"
#include "mozilla/AppUnits.h"
#include "prclist.h"
#include "nsThreadUtils.h"
#include "ScrollbarStyles.h"
#include "nsIMessageManager.h"
#include "mozilla/RestyleLogging.h"
#include "Units.h"
#include "mozilla/RestyleManagerHandle.h"
#include "prenv.h"
#include "mozilla/StaticPresData.h"
#include "mozilla/StyleBackendType.h"

class nsAString;
class nsIPrintSettings;
class nsDocShell;
class nsIDocShell;
class nsIDocument;
class nsILanguageAtomService;
class nsITheme;
class nsIContent;
class nsIFrame;
class nsFrameManager;
class nsILinkHandler;
class nsIAtom;
class nsIRunnable;
class gfxUserFontEntry;
class gfxUserFontSet;
class gfxTextPerfMetrics;
class nsPluginFrame;
class nsTransitionManager;
class nsAnimationManager;
class nsRefreshDriver;
class nsIWidget;
class nsDeviceContext;
class gfxMissingFontRecorder;

namespace mozilla {
class EffectCompositor;
class EventStateManager;
class CounterStyleManager;
namespace layers {
class ContainerLayer;
class LayerManager;
} // namespace layers
namespace dom {
class Element;
} // namespace dom
} // namespace mozilla

// supported values for cached bool types
enum nsPresContext_CachedBoolPrefType {
  kPresContext_UseDocumentFonts = 1,
  kPresContext_UnderlineLinks
};

// supported values for cached integer pref types
enum nsPresContext_CachedIntPrefType {
  kPresContext_ScrollbarSide = 1,
  kPresContext_BidiDirection
};

// IDs for the default variable and fixed fonts (not to be changed, see nsFont.h)
// To be used for Get/SetDefaultFont(). The other IDs in nsFont.h are also supported.
const uint8_t kPresContext_DefaultVariableFont_ID = 0x00; // kGenericFont_moz_variable
const uint8_t kPresContext_DefaultFixedFont_ID    = 0x01; // kGenericFont_moz_fixed

#ifdef DEBUG
struct nsAutoLayoutPhase;

enum nsLayoutPhase {
  eLayoutPhase_Paint,
  eLayoutPhase_Reflow,
  eLayoutPhase_FrameC,
  eLayoutPhase_COUNT
};
#endif

class nsInvalidateRequestList {
public:
  struct Request {
    nsRect   mRect;
    uint32_t mFlags;
  };

  void TakeFrom(nsInvalidateRequestList* aList)
  {
    mRequests.AppendElements(mozilla::Move(aList->mRequests));
  }
  bool IsEmpty() { return mRequests.IsEmpty(); }

  nsTArray<Request> mRequests;
};

/* Used by nsPresContext::HasAuthorSpecifiedRules */
#define NS_AUTHOR_SPECIFIED_BACKGROUND      (1 << 0)
#define NS_AUTHOR_SPECIFIED_BORDER          (1 << 1)
#define NS_AUTHOR_SPECIFIED_PADDING         (1 << 2)
#define NS_AUTHOR_SPECIFIED_TEXT_SHADOW     (1 << 3)

class nsRootPresContext;

// An interface for presentation contexts. Presentation contexts are
// objects that provide an outer context for a presentation shell.

class nsPresContext : public nsIObserver,
                      public mozilla::SupportsWeakPtr<nsPresContext> {
public:
  typedef mozilla::FramePropertyTable FramePropertyTable;
  typedef mozilla::LangGroupFontPrefs LangGroupFontPrefs;
  typedef mozilla::ScrollbarStyles ScrollbarStyles;
  typedef mozilla::StaticPresData StaticPresData;

  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
  NS_DECL_NSIOBSERVER
  NS_DECL_AND_IMPL_ZEROING_OPERATOR_NEW
  NS_DECL_CYCLE_COLLECTION_CLASS(nsPresContext)
  MOZ_DECLARE_WEAKREFERENCE_TYPENAME(nsPresContext)

  enum nsPresContextType {
    eContext_Galley,       // unpaginated screen presentation
    eContext_PrintPreview, // paginated screen presentation
    eContext_Print,        // paginated printer presentation
    eContext_PageLayout    // paginated & editable.
  };

  nsPresContext(nsIDocument* aDocument, nsPresContextType aType);

  /**
   * Initialize the presentation context from a particular device.
   */
  nsresult Init(nsDeviceContext* aDeviceContext);

  /**
   * Set and detach presentation shell that this context is bound to.
   * A presentation context may only be bound to a single shell.
   */
  void AttachShell(nsIPresShell* aShell, mozilla::StyleBackendType aBackendType);
  void DetachShell();


  nsPresContextType Type() const { return mType; }

  /**
   * Get the PresentationShell that this context is bound to.
   */
  nsIPresShell* PresShell() const
  {
    NS_ASSERTION(mShell, "Null pres shell");
    return mShell;
  }

  nsIPresShell* GetPresShell() const { return mShell; }

  /**
   * Returns the parent prescontext for this one. Returns null if this is a
   * root.
   */
  nsPresContext* GetParentPresContext();

  /**
   * Returns the prescontext of the toplevel content document that contains
   * this presentation, or null if there isn't one.
   */
  nsPresContext* GetToplevelContentDocumentPresContext();

  /**
   * Returns the nearest widget for the root frame of this.
   *
   * @param aOffset     If non-null the offset from the origin of the root
   *                    frame's view to the widget's origin (usually positive)
   *                    expressed in appunits of this will be returned in
   *                    aOffset.
   */
  nsIWidget* GetNearestWidget(nsPoint* aOffset = nullptr);

  /**
   * Returns the root widget for this.
   * Note that the widget is a mediater with IME.
   */
  nsIWidget* GetRootWidget();

  /**
   * Return the presentation context for the root of the view manager
   * hierarchy that contains this presentation context, or nullptr if it can't
   * be found (e.g. it's detached).
   */
  nsRootPresContext* GetRootPresContext();

  virtual bool IsRoot() { return false; }

  nsIDocument* Document() const
  {
      NS_ASSERTION(!mShell || !mShell->GetDocument() ||
                   mShell->GetDocument() == mDocument,
                   "nsPresContext doesn't have the same document as nsPresShell!");
      return mDocument;
  }

#ifdef MOZILLA_INTERNAL_API
  mozilla::StyleSetHandle StyleSet() { return GetPresShell()->StyleSet(); }

  nsFrameManager* FrameManager()
    { return PresShell()->FrameManager(); }

  nsCSSFrameConstructor* FrameConstructor()
    { return PresShell()->FrameConstructor(); }

  mozilla::EffectCompositor* EffectCompositor() { return mEffectCompositor; }
  nsTransitionManager* TransitionManager() { return mTransitionManager; }
  nsAnimationManager* AnimationManager() { return mAnimationManager; }

  nsRefreshDriver* RefreshDriver() { return mRefreshDriver; }

  mozilla::RestyleManagerHandle RestyleManager() {
    MOZ_ASSERT(mRestyleManager);
    return mRestyleManager;
  }

  mozilla::CounterStyleManager* CounterStyleManager() {
    return mCounterStyleManager;
  }
#endif

  /**
   * Rebuilds all style data by throwing out the old rule tree and
   * building a new one, and additionally applying aExtraHint (which
   * must not contain nsChangeHint_ReconstructFrame) to the root frame.
   * For aRestyleHint, see RestyleManager::RebuildAllStyleData.
   * Also rebuild the user font set and counter style manager.
   */
  void RebuildAllStyleData(nsChangeHint aExtraHint, nsRestyleHint aRestyleHint);
  /**
   * Just like RebuildAllStyleData, except (1) asynchronous and (2) it
   * doesn't rebuild the user font set.
   */
  void PostRebuildAllStyleDataEvent(nsChangeHint aExtraHint,
                                    nsRestyleHint aRestyleHint);

  /**
   * Handle changes in the values of media features (used in media
   * queries).
   *
   * There are three sensible values to use for aRestyleHint:
   *  * nsRestyleHint(0) to rebuild style data, with rerunning of
   *    selector matching, only if media features have changed
   *  * eRestyle_ForceDescendants to force rebuilding of style data (but
   *    still only rerun selector matching if media query results have
   *    changed).  (RebuildAllStyleData always adds
   *    eRestyle_ForceDescendants internally, so here we're only using
   *    it to distinguish from nsRestyleHint(0) whether we need to call
   *    RebuildAllStyleData at all.)
   *  * eRestyle_Subtree to force rebuilding of style data with
   *    rerunning of selector matching
   *
   * For aChangeHint, see RestyleManager::RebuildAllStyleData.  (Passing
   * a nonzero aChangeHint forces rebuilding style data even if
   * nsRestyleHint(0) is passed.)
   */
  void MediaFeatureValuesChanged(nsRestyleHint aRestyleHint,
                                 nsChangeHint aChangeHint = nsChangeHint(0));
  /**
   * Calls MediaFeatureValuesChanged for this pres context and all descendant
   * subdocuments that have a pres context. This should be used for media
   * features that must be updated in all subdocuments e.g. display-mode.
   */
  void MediaFeatureValuesChangedAllDocuments(nsRestyleHint aRestyleHint,
                                             nsChangeHint aChangeHint = nsChangeHint(0));

  void PostMediaFeatureValuesChangedEvent();
  void HandleMediaFeatureValuesChangedEvent();
  void FlushPendingMediaFeatureValuesChanged() {
    if (mPendingMediaFeatureValuesChanged)
      MediaFeatureValuesChanged(nsRestyleHint(0));
  }

  /**
   * Updates the size mode on all remote children and recursively notifies this
   * document and all subdocuments (including remote children) that a media
   * feature value has changed.
   */
  void SizeModeChanged(nsSizeMode aSizeMode);

  /**
   * Access compatibility mode for this context.  This is the same as
   * our document's compatibility mode.
   */
  nsCompatibility CompatibilityMode() const;

  /**
   * Notify the context that the document's compatibility mode has changed
   */
  void CompatibilityModeChanged();

  /**
   * Access the image animation mode for this context
   */
  uint16_t     ImageAnimationMode() const { return mImageAnimationMode; }
  virtual void SetImageAnimationModeExternal(uint16_t aMode);
  void SetImageAnimationModeInternal(uint16_t aMode);
#ifdef MOZILLA_INTERNAL_API
  void SetImageAnimationMode(uint16_t aMode)
  { SetImageAnimationModeInternal(aMode); }
#else
  void SetImageAnimationMode(uint16_t aMode)
  { SetImageAnimationModeExternal(aMode); }
#endif

  /**
   * Get medium of presentation
   */
  nsIAtom* Medium() {
    if (!mIsEmulatingMedia)
      return mMedium;
    return mMediaEmulated;
  }

  /*
   * Render the document as if being viewed on a device with the specified
   * media type.
   */
  void EmulateMedium(const nsAString& aMediaType);

  /*
   * Restore the viewer's natural medium
   */
  void StopEmulatingMedium();

  void* AllocateFromShell(size_t aSize)
  {
    if (mShell)
      return mShell->AllocateMisc(aSize);
    return nullptr;
  }

  void FreeToShell(size_t aSize, void* aFreeChunk)
  {
    NS_ASSERTION(mShell, "freeing after shutdown");
    if (mShell)
      mShell->FreeMisc(aSize, aFreeChunk);
  }

  /**
   * Get the default font for the given language and generic font ID.
   * If aLanguage is nullptr, the document's language is used.
   *
   * See the comment in StaticPresData::GetDefaultFont.
   */
  const nsFont* GetDefaultFont(uint8_t aFontID,
                               nsIAtom *aLanguage) const
  {
    nsIAtom* lang = aLanguage ? aLanguage : mLanguage.get();
    return StaticPresData::Get()->GetDefaultFontHelper(aFontID, lang,
                                                       GetFontPrefsForLang(lang));
  }

  /** Get a cached boolean pref, by its type */
  // *  - initially created for bugs 31816, 20760, 22963
  bool GetCachedBoolPref(nsPresContext_CachedBoolPrefType aPrefType) const
  {
    // If called with a constant parameter, the compiler should optimize
    // this switch statement away.
    switch (aPrefType) {
    case kPresContext_UseDocumentFonts:
      return mUseDocumentFonts;
    case kPresContext_UnderlineLinks:
      return mUnderlineLinks;
    default:
      NS_ERROR("Invalid arg passed to GetCachedBoolPref");
    }

    return false;
  }

  /** Get a cached integer pref, by its type */
  // *  - initially created for bugs 30910, 61883, 74186, 84398
  int32_t GetCachedIntPref(nsPresContext_CachedIntPrefType aPrefType) const
  {
    // If called with a constant parameter, the compiler should optimize
    // this switch statement away.
    switch (aPrefType) {
    case kPresContext_ScrollbarSide:
      return mPrefScrollbarSide;
    case kPresContext_BidiDirection:
      return mPrefBidiDirection;
    default:
      NS_ERROR("invalid arg passed to GetCachedIntPref");
    }

    return false;
  }

  /**
   * Get the default colors
   */
  nscolor DefaultColor() const { return mDefaultColor; }
  nscolor DefaultBackgroundColor() const { return mBackgroundColor; }
  nscolor DefaultLinkColor() const { return mLinkColor; }
  nscolor DefaultActiveLinkColor() const { return mActiveLinkColor; }
  nscolor DefaultVisitedLinkColor() const { return mVisitedLinkColor; }
  nscolor FocusBackgroundColor() const { return mFocusBackgroundColor; }
  nscolor FocusTextColor() const { return mFocusTextColor; }

  /**
   * Body text color, for use in quirks mode only.
   */
  nscolor BodyTextColor() const { return mBodyTextColor; }
  void SetBodyTextColor(nscolor aColor) { mBodyTextColor = aColor; }

  bool GetUseFocusColors() const { return mUseFocusColors; }
  uint8_t FocusRingWidth() const { return mFocusRingWidth; }
  bool GetFocusRingOnAnything() const { return mFocusRingOnAnything; }
  uint8_t GetFocusRingStyle() const { return mFocusRingStyle; }

  void SetContainer(nsIDocShell* aContainer);

  virtual nsISupports* GetContainerWeakExternal() const;
  nsISupports* GetContainerWeakInternal() const;
#ifdef MOZILLA_INTERNAL_API
  nsISupports* GetContainerWeak() const
  { return GetContainerWeakInternal(); }
#else
  nsISupports* GetContainerWeak() const
  { return GetContainerWeakExternal(); }
#endif

  nsIDocShell* GetDocShell() const;

  // XXX this are going to be replaced with set/get container
  void SetLinkHandler(nsILinkHandler* aHandler) { mLinkHandler = aHandler; }
  nsILinkHandler* GetLinkHandler() { return mLinkHandler; }

  /**
   * Detach this pres context - i.e. cancel relevant timers,
   * SetLinkHandler(null), SetContainer(null) etc.
   * Only to be used by the DocumentViewer.
   */
  virtual void Detach();

  /**
   * Get the visible area associated with this presentation context.
   * This is the size of the visible area that is used for
   * presenting the document. The returned value is in the standard
   * nscoord units (as scaled by the device context).
   */
  nsRect GetVisibleArea() const { return mVisibleArea; }

  /**
   * Set the currently visible area. The units for r are standard
   * nscoord units (as scaled by the device context).
   */
  void SetVisibleArea(const nsRect& r) {
    if (!r.IsEqualEdges(mVisibleArea)) {
      mVisibleArea = r;
      // Visible area does not affect media queries when paginated.
      if (!IsPaginated() && HasCachedStyleData()) {
        mPendingViewportChange = true;
        PostMediaFeatureValuesChangedEvent();
      }
    }
  }

  /**
   * Return true if this presentation context is a paginated
   * context.
   */
  bool IsPaginated() const { return mPaginated; }

  /**
   * Sets whether the presentation context can scroll for a paginated
   * context.
   */
  void SetPaginatedScrolling(bool aResult);

  /**
   * Return true if this presentation context can scroll for paginated
   * context.
   */
  bool HasPaginatedScrolling() const { return mCanPaginatedScroll; }

  /**
   * Get/set the size of a page
   */
  nsSize GetPageSize() { return mPageSize; }
  void SetPageSize(nsSize aSize) { mPageSize = aSize; }

  /**
   * Get/set whether this document should be treated as having real pages
   * XXX This raises the obvious question of why a document that isn't a page
   *     is paginated; there isn't a good reason except history
   */
  bool IsRootPaginatedDocument() { return mIsRootPaginatedDocument; }
  void SetIsRootPaginatedDocument(bool aIsRootPaginatedDocument)
    { mIsRootPaginatedDocument = aIsRootPaginatedDocument; }

  /**
  * Get/set the print scaling level; used by nsPageFrame to scale up
  * pages.  Set safe to call before reflow, get guaranteed to be set
  * properly after reflow.
  */

  float GetPageScale() { return mPageScale; }
  void SetPageScale(float aScale) { mPageScale = aScale; }

  /**
  * Get/set the scaling facor to use when rendering the pages for print preview.
  * Only safe to get after print preview set up; safe to set anytime.
  * This is a scaling factor for the display of the print preview.  It
  * does not affect layout.  It only affects the size of the onscreen pages
  * in print preview.
  * XXX Temporary: see http://wiki.mozilla.org/Gecko:PrintPreview
  */
  float GetPrintPreviewScale() { return mPPScale; }
  void SetPrintPreviewScale(float aScale) { mPPScale = aScale; }

  nsDeviceContext* DeviceContext() { return mDeviceContext; }
  mozilla::EventStateManager* EventStateManager() { return mEventManager; }
  nsIAtom* GetLanguageFromCharset() const { return mLanguage; }
  already_AddRefed<nsIAtom> GetContentLanguage() const;

  float TextZoom() { return mTextZoom; }
  void SetTextZoom(float aZoom) {
    MOZ_ASSERT(aZoom > 0.0f, "invalid zoom factor");
    if (aZoom == mTextZoom)
      return;

    mTextZoom = aZoom;
    if (HasCachedStyleData()) {
      // Media queries could have changed, since we changed the meaning
      // of 'em' units in them.
      MediaFeatureValuesChanged(eRestyle_ForceDescendants,
                                NS_STYLE_HINT_REFLOW);
    }
  }

  /**
   * Get the minimum font size for the specified language. If aLanguage
   * is nullptr, then the document's language is used.  This combines
   * the language-specific global preference with the per-presentation
   * base minimum font size.
   */
  int32_t MinFontSize(nsIAtom *aLanguage) const {
    const LangGroupFontPrefs *prefs = GetFontPrefsForLang(aLanguage);
    return std::max(mBaseMinFontSize, prefs->mMinimumFontSize);
  }

  /**
   * Get the per-presentation base minimum font size.  This size is
   * independent of the language-specific global preference.
   */
  int32_t BaseMinFontSize() const {
    return mBaseMinFontSize;
  }

  /**
   * Set the per-presentation base minimum font size.  This size is
   * independent of the language-specific global preference.
   */
  void SetBaseMinFontSize(int32_t aMinFontSize) {
    if (aMinFontSize == mBaseMinFontSize)
      return;

    mBaseMinFontSize = aMinFontSize;
    if (HasCachedStyleData()) {
      // Media queries could have changed, since we changed the meaning
      // of 'em' units in them.
      MediaFeatureValuesChanged(eRestyle_ForceDescendants,
                                NS_STYLE_HINT_REFLOW);
    }
  }

  float GetFullZoom() { return mFullZoom; }
  void SetFullZoom(float aZoom);

  float GetOverrideDPPX() { return mOverrideDPPX; }
  void SetOverrideDPPX(float aDPPX);

  nscoord GetAutoQualityMinFontSize() {
    return DevPixelsToAppUnits(mAutoQualityMinFontSizePixelsPref);
  }

  /**
   * Return the device's screen size in inches, for font size
   * inflation.
   *
   * If |aChanged| is non-null, then aChanged is filled in with whether
   * the screen size value has changed since either:
   *  a. the last time the function was called with non-null aChanged, or
   *  b. the first time the function was called.
   */
  gfxSize ScreenSizeInchesForFontInflation(bool* aChanged = nullptr);

  static int32_t AppUnitsPerCSSPixel() { return mozilla::AppUnitsPerCSSPixel(); }
  int32_t AppUnitsPerDevPixel() const;
  static int32_t AppUnitsPerCSSInch() { return mozilla::AppUnitsPerCSSInch(); }

  static nscoord CSSPixelsToAppUnits(int32_t aPixels)
  { return NSToCoordRoundWithClamp(float(aPixels) *
             float(AppUnitsPerCSSPixel())); }

  static nscoord CSSPixelsToAppUnits(float aPixels)
  { return NSToCoordRoundWithClamp(aPixels *
             float(AppUnitsPerCSSPixel())); }

  static int32_t AppUnitsToIntCSSPixels(nscoord aAppUnits)
  { return NSAppUnitsToIntPixels(aAppUnits,
             float(AppUnitsPerCSSPixel())); }

  static float AppUnitsToFloatCSSPixels(nscoord aAppUnits)
  { return NSAppUnitsToFloatPixels(aAppUnits,
             float(AppUnitsPerCSSPixel())); }

  static double AppUnitsToDoubleCSSPixels(nscoord aAppUnits)
  { return NSAppUnitsToDoublePixels(aAppUnits,
             double(AppUnitsPerCSSPixel())); }

  nscoord DevPixelsToAppUnits(int32_t aPixels) const
  { return NSIntPixelsToAppUnits(aPixels, AppUnitsPerDevPixel()); }

  int32_t AppUnitsToDevPixels(nscoord aAppUnits) const
  { return NSAppUnitsToIntPixels(aAppUnits,
             float(AppUnitsPerDevPixel())); }

  float AppUnitsToFloatDevPixels(nscoord aAppUnits)
  { return aAppUnits / float(AppUnitsPerDevPixel()); }

  int32_t CSSPixelsToDevPixels(int32_t aPixels)
  { return AppUnitsToDevPixels(CSSPixelsToAppUnits(aPixels)); }

  float CSSPixelsToDevPixels(float aPixels)
  {
    return NSAppUnitsToFloatPixels(CSSPixelsToAppUnits(aPixels),
                                   float(AppUnitsPerDevPixel()));
  }

  int32_t DevPixelsToIntCSSPixels(int32_t aPixels)
  { return AppUnitsToIntCSSPixels(DevPixelsToAppUnits(aPixels)); }

  float DevPixelsToFloatCSSPixels(int32_t aPixels)
  { return AppUnitsToFloatCSSPixels(DevPixelsToAppUnits(aPixels)); }

  mozilla::CSSToLayoutDeviceScale CSSToDevPixelScale() const
  {
    return mozilla::CSSToLayoutDeviceScale(
        float(AppUnitsPerCSSPixel()) / float(AppUnitsPerDevPixel()));
  }

  // If there is a remainder, it is rounded to nearest app units.
  nscoord GfxUnitsToAppUnits(gfxFloat aGfxUnits) const;

  gfxFloat AppUnitsToGfxUnits(nscoord aAppUnits) const;

  gfxRect AppUnitsToGfxUnits(const nsRect& aAppRect) const
  { return gfxRect(AppUnitsToGfxUnits(aAppRect.x),
                   AppUnitsToGfxUnits(aAppRect.y),
                   AppUnitsToGfxUnits(aAppRect.width),
                   AppUnitsToGfxUnits(aAppRect.height)); }

  static nscoord CSSTwipsToAppUnits(float aTwips)
  { return NSToCoordRoundWithClamp(
      mozilla::AppUnitsPerCSSInch() * NS_TWIPS_TO_INCHES(aTwips)); }

  // Margin-specific version, since they often need TwipsToAppUnits
  static nsMargin CSSTwipsToAppUnits(const nsIntMargin &marginInTwips)
  { return nsMargin(CSSTwipsToAppUnits(float(marginInTwips.top)),
                    CSSTwipsToAppUnits(float(marginInTwips.right)),
                    CSSTwipsToAppUnits(float(marginInTwips.bottom)),
                    CSSTwipsToAppUnits(float(marginInTwips.left))); }

  static nscoord CSSPointsToAppUnits(float aPoints)
  { return NSToCoordRound(aPoints * mozilla::AppUnitsPerCSSInch() /
                          POINTS_PER_INCH_FLOAT); }

  nscoord RoundAppUnitsToNearestDevPixels(nscoord aAppUnits) const
  { return DevPixelsToAppUnits(AppUnitsToDevPixels(aAppUnits)); }

  /**
   * This checks the root element and the HTML BODY, if any, for an "overflow"
   * property that should be applied to the viewport. If one is found then we
   * return the element that we took the overflow from (which should then be
   * treated as "overflow: visible"), and we store the overflow style here.
   * If the document is in fullscreen, and the fullscreen element is not the
   * root, the scrollbar of viewport will be suppressed.
   * @return if scroll was propagated from some content node, the content node
   *         it was propagated from.
   */
  nsIContent* UpdateViewportScrollbarStylesOverride();

  /**
   * Returns the cached result from the last call to
   * UpdateViewportScrollbarStylesOverride() -- i.e. return the node
   * whose scrollbar styles we have propagated to the viewport (or nullptr if
   * there is no such node).
   */
  nsIContent* GetViewportScrollbarStylesOverrideNode() const {
    return mViewportScrollbarOverrideNode;
  }

  const ScrollbarStyles& GetViewportScrollbarStylesOverride() const
  {
    return mViewportStyleScrollbar;
  }

  /**
   * Check whether the given element would propagate its scrollbar styles to the
   * viewport in non-paginated mode.  Must only be called if IsPaginated().
   */
  bool ElementWouldPropagateScrollbarStyles(mozilla::dom::Element* aElement);

  /**
   * Set and get methods for controlling the background drawing
  */
  bool GetBackgroundImageDraw() const { return mDrawImageBackground; }
  void   SetBackgroundImageDraw(bool aCanDraw)
  {
    mDrawImageBackground = aCanDraw;
  }

  bool GetBackgroundColorDraw() const { return mDrawColorBackground; }
  void   SetBackgroundColorDraw(bool aCanDraw)
  {
    mDrawColorBackground = aCanDraw;
  }

  /**
   *  Check if bidi enabled (set depending on the presence of RTL
   *  characters or when default directionality is RTL).
   *  If enabled, we should apply the Unicode Bidi Algorithm
   *
   *  @lina 07/12/2000
   */
#ifdef MOZILLA_INTERNAL_API
  bool BidiEnabled() const { return BidiEnabledInternal(); }
#else
  bool BidiEnabled() const { return BidiEnabledExternal(); }
#endif
  virtual bool BidiEnabledExternal() const;
  bool BidiEnabledInternal() const;

  /**
   *  Set bidi enabled. This means we should apply the Unicode Bidi Algorithm
   *
   *  @lina 07/12/2000
   */
  void SetBidiEnabled() const;

  /**
   *  Set visual or implicit mode into the pres context.
   *
   *  Visual directionality is a presentation method that displays text
   *  as if it were a uni-directional, according to the primary display
   *  direction only.
   *
   *  Implicit directionality is a presentation method in which the
   *  direction is determined by the Bidi algorithm according to the
   *  category of the characters and the category of the adjacent
   *  characters, and according to their primary direction.
   *
   *  @lina 05/02/2000
   */
  void SetVisualMode(bool aIsVisual)
  {
    mIsVisual = aIsVisual;
  }

  /**
   *  Check whether the content should be treated as visual.
   *
   *  @lina 05/02/2000
   */
  bool IsVisualMode() const { return mIsVisual; }

//Mohamed

  /**
   * Set the Bidi options for the presentation context
   */
  void SetBidi(uint32_t aBidiOptions,
                           bool aForceRestyle = false);

  /**
   * Get the Bidi options for the presentation context
   * Not inline so consumers of nsPresContext are not forced to
   * include nsIDocument.
   */
  uint32_t GetBidi() const;

  /**
   * Render only Selection
   */
  void SetIsRenderingOnlySelection(bool aResult)
  {
    mIsRenderingOnlySelection = aResult;
  }

  bool IsRenderingOnlySelection() const { return mIsRenderingOnlySelection; }

  bool IsTopLevelWindowInactive();

  /*
   * Obtain a native them for rendering our widgets (both form controls and html)
   */
  nsITheme* GetTheme();

  /*
   * Notify the pres context that the theme has changed.  An internal switch
   * means it's one of our Mozilla themes that changed (e.g., Modern to Classic).
   * Otherwise, the OS is telling us that the native theme for the platform
   * has changed.
   */
  void ThemeChanged();

  /*
   * Notify the pres context that the resolution of the user interface has
   * changed. This happens if a window is moved between HiDPI and non-HiDPI
   * displays, so that the ratio of points to device pixels changes.
   * The notification happens asynchronously.
   */
  void UIResolutionChanged();

 /*
  * Like UIResolutionChanged() but invalidates values immediately.
  */
  void UIResolutionChangedSync();

  /*
   * Notify the pres context that a system color has changed
   */
  void SysColorChanged();

  /** Printing methods below should only be used for Medium() == print **/
  void SetPrintSettings(nsIPrintSettings *aPrintSettings);

  nsIPrintSettings* GetPrintSettings() { return mPrintSettings; }

  /* Accessor for table of frame properties */
  FramePropertyTable* PropertyTable() { return &mPropertyTable; }

  /* Helper function that ensures that this prescontext is shown in its
     docshell if it's the most recent prescontext for the docshell.  Returns
     whether the prescontext is now being shown.
  */
  bool EnsureVisible();

#ifdef MOZ_REFLOW_PERF
  void CountReflows(const char * aName,
                                nsIFrame * aFrame);
#endif

  void RestyledElement() {
    ++mElementsRestyled;
  }
  void ConstructedFrame() {
    ++mFramesConstructed;
  }
  void ReflowedFrame() {
    ++mFramesReflowed;
  }

  uint64_t ElementsRestyledCount() {
    return mElementsRestyled;
  }
  uint64_t FramesConstructedCount() {
    return mFramesConstructed;
  }
  uint64_t FramesReflowedCount() {
    return mFramesReflowed;
  }

  /**
   * This table maps border-width enums 'thin', 'medium', 'thick'
   * to actual nscoord values.
   */
  const nscoord* GetBorderWidthTable() { return mBorderWidthTable; }

  gfxTextPerfMetrics *GetTextPerfMetrics() { return mTextPerf; }

  bool IsDynamic() { return (mType == eContext_PageLayout || mType == eContext_Galley); }
  bool IsScreen() { return (mMedium == nsGkAtoms::screen ||
                              mType == eContext_PageLayout ||
                              mType == eContext_PrintPreview); }

  // Is this presentation in a chrome docshell?
  bool IsChrome() const { return mIsChrome; }
  bool IsChromeOriginImage() const { return mIsChromeOriginImage; }
  void UpdateIsChrome();

  // Public API for native theme code to get style internals.
  bool HasAuthorSpecifiedRules(const nsIFrame *aFrame,
                               uint32_t ruleTypeMask) const;

  // Is it OK to let the page specify colors and backgrounds?
  bool UseDocumentColors() const {
    MOZ_ASSERT(mUseDocumentColors || !(IsChrome() || IsChromeOriginImage()),
               "We should never have a chrome doc or image that can't use its colors.");
    return mUseDocumentColors;
  }

  // Explicitly enable and disable paint flashing.
  void SetPaintFlashing(bool aPaintFlashing) {
    mPaintFlashing = aPaintFlashing;
    mPaintFlashingInitialized = true;
  }

  // This method should be used instead of directly accessing mPaintFlashing,
  // as that value may be out of date when mPaintFlashingInitialized is false.
  bool GetPaintFlashing() const;

  bool             SuppressingResizeReflow() const { return mSuppressResizeReflow; }

  gfxUserFontSet* GetUserFontSet(bool aFlushUserFontSet = true);

  // Should be called whenever the set of fonts available in the user
  // font set changes (e.g., because a new font loads, or because the
  // user font set is changed and fonts become unavailable).
  void UserFontSetUpdated(gfxUserFontEntry* aUpdatedFont = nullptr);

  gfxMissingFontRecorder *MissingFontRecorder() { return mMissingFonts; }
  void NotifyMissingFonts();

  void FlushCounterStyles();
  void RebuildCounterStyles(); // asynchronously

  // Ensure that it is safe to hand out CSS rules outside the layout
  // engine by ensuring that all CSS style sheets have unique inners
  // and, if necessary, synchronously rebuilding all style data.
  void EnsureSafeToHandOutCSSRules();

  void NotifyInvalidation(uint32_t aFlags);
  void NotifyInvalidation(const nsRect& aRect, uint32_t aFlags);
  // aRect is in device pixels
  void NotifyInvalidation(const nsIntRect& aRect, uint32_t aFlags);
  // aFlags are nsIPresShell::PAINT_ flags
  void NotifyDidPaintForSubtree(uint32_t aFlags, uint64_t aTransactionId = 0,
                                const mozilla::TimeStamp& aTimeStamp = mozilla::TimeStamp());
  void FireDOMPaintEvent(nsInvalidateRequestList* aList, uint64_t aTransactionId);

  // Callback for catching invalidations in ContainerLayers
  // Passed to LayerProperties::ComputeDifference
  static void NotifySubDocInvalidation(mozilla::layers::ContainerLayer* aContainer,
                                       const nsIntRegion& aRegion);
  void SetNotifySubDocInvalidationData(mozilla::layers::ContainerLayer* aContainer);
  static void ClearNotifySubDocInvalidationData(mozilla::layers::ContainerLayer* aContainer);
  bool IsDOMPaintEventPending();
  void ClearMozAfterPaintEvents() {
    mInvalidateRequestsSinceLastPaint.mRequests.Clear();
    mUndeliveredInvalidateRequestsBeforeLastPaint.mRequests.Clear();
    mAllInvalidated = false;
  }

  /**
   * Returns the RestyleManager's restyle generation counter.
   */
  uint64_t GetRestyleGeneration() const;

  /**
   * Returns whether there are any pending restyles or reflows.
   */
  bool HasPendingRestyleOrReflow();

  /**
   * Informs the document's FontFaceSet that the refresh driver ticked,
   * flushing style and layout.
   */
  void NotifyFontFaceSetOnRefresh();

  /**
   * Notify the prescontext that the presshell is about to reflow a reflow root.
   * The single argument indicates whether this reflow should be interruptible.
   * If aInterruptible is false then CheckForInterrupt and HasPendingInterrupt
   * will always return false. If aInterruptible is true then CheckForInterrupt
   * will return true when a pending event is detected.  This is for use by the
   * presshell only.  Reflow code wanting to prevent interrupts should use
   * InterruptPreventer.
   */
  void ReflowStarted(bool aInterruptible);

  /**
   * A class that can be used to temporarily disable reflow interruption.
   */
  class InterruptPreventer;
  friend class InterruptPreventer;
  class MOZ_STACK_CLASS InterruptPreventer {
  public:
    explicit InterruptPreventer(nsPresContext* aCtx) :
      mCtx(aCtx),
      mInterruptsEnabled(aCtx->mInterruptsEnabled),
      mHasPendingInterrupt(aCtx->mHasPendingInterrupt)
    {
      mCtx->mInterruptsEnabled = false;
      mCtx->mHasPendingInterrupt = false;
    }
    ~InterruptPreventer() {
      mCtx->mInterruptsEnabled = mInterruptsEnabled;
      mCtx->mHasPendingInterrupt = mHasPendingInterrupt;
    }

  private:
    nsPresContext* mCtx;
    bool mInterruptsEnabled;
    bool mHasPendingInterrupt;
  };

  /**
   * Check for interrupts. This may return true if a pending event is
   * detected. Once it has returned true, it will keep returning true
   * until ReflowStarted is called. In all cases where this returns true,
   * the passed-in frame (which should be the frame whose reflow will be
   * interrupted if true is returned) will be passed to
   * nsIPresShell::FrameNeedsToContinueReflow.
   */
  bool CheckForInterrupt(nsIFrame* aFrame);
  /**
   * Returns true if CheckForInterrupt has returned true since the last
   * ReflowStarted call. Cannot itself trigger an interrupt check.
   */
  bool HasPendingInterrupt() { return mHasPendingInterrupt; }
  /**
   * Sets a flag that will trip a reflow interrupt. This only bypasses the
   * interrupt timeout and the pending event check; other checks such as whether
   * interrupts are enabled and the interrupt check skipping still take effect.
   */
  void SetPendingInterruptFromTest() { mPendingInterruptFromTest = true; }

  /**
   * If we have a presshell, and if the given content's current
   * document is the same as our presshell's document, return the
   * content's primary frame.  Otherwise, return null.  Only use this
   * if you care about which presshell the primary frame is in.
   */
  nsIFrame* GetPrimaryFrameFor(nsIContent* aContent);

  void NotifyDestroyingFrame(nsIFrame* aFrame)
  {
    PropertyTable()->DeleteAllFor(aFrame);
  }

  virtual size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
  virtual size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const {
    return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
  }

  bool IsRootContentDocument() const;

  bool HadNonBlankPaint() const {
    return mHadNonBlankPaint;
  }

  void NotifyNonBlankPaint();

  bool IsGlyph() const {
    return mIsGlyph;
  }

  void SetIsGlyph(bool aValue) {
    mIsGlyph = aValue;
  }

  bool UsesRootEMUnits() const {
    return mUsesRootEMUnits;
  }

  void SetUsesRootEMUnits(bool aValue) {
    mUsesRootEMUnits = aValue;
  }

  bool UsesExChUnits() const {
    return mUsesExChUnits;
  }

  void SetUsesExChUnits(bool aValue) {
    mUsesExChUnits = aValue;
  }

  bool UsesViewportUnits() const {
    return mUsesViewportUnits;
  }

  void SetUsesViewportUnits(bool aValue) {
    mUsesViewportUnits = aValue;
  }

  // true if there are OMTA transition updates for the current document which
  // have been throttled, and therefore some style information may not be up
  // to date
  bool ExistThrottledUpdates() const {
    return mExistThrottledUpdates;
  }

  void SetExistThrottledUpdates(bool aExistThrottledUpdates) {
    mExistThrottledUpdates = aExistThrottledUpdates;
  }

  bool IsDeviceSizePageSize();

  bool HasWarnedAboutPositionedTableParts() const {
    return mHasWarnedAboutPositionedTableParts;
  }

  void SetHasWarnedAboutPositionedTableParts() {
    mHasWarnedAboutPositionedTableParts = true;
  }

  bool HasWarnedAboutTooLargeDashedOrDottedRadius() const {
    return mHasWarnedAboutTooLargeDashedOrDottedRadius;
  }

  void SetHasWarnedAboutTooLargeDashedOrDottedRadius() {
    mHasWarnedAboutTooLargeDashedOrDottedRadius = true;
  }

protected:
  friend class nsRunnableMethod<nsPresContext>;
  void ThemeChangedInternal();
  void SysColorChangedInternal();

  // update device context's resolution from the widget
  void UIResolutionChangedInternal();

  // if aScale > 0.0, use it as resolution scale factor to the device context
  // (otherwise get it from the widget)
  void UIResolutionChangedInternalScale(double aScale);

  // aData here is a pointer to a double that holds the CSS to device-pixel
  // scale factor from the parent, which will be applied to the subdocument's
  // device context instead of retrieving a scale from the widget.
  static bool
  UIResolutionChangedSubdocumentCallback(nsIDocument* aDocument, void* aData);

  void SetImgAnimations(nsIContent *aParent, uint16_t aMode);
  void SetSMILAnimations(nsIDocument *aDoc, uint16_t aNewMode,
                                     uint16_t aOldMode);
  void GetDocumentColorPreferences();

  void PreferenceChanged(const char* aPrefName);
  static void PrefChangedCallback(const char*, void*);

  void UpdateAfterPreferencesChanged();
  static void PrefChangedUpdateTimerCallback(nsITimer *aTimer, void *aClosure);

  void GetUserPreferences();

  /**
   * Fetch the user's font preferences for the given aLanguage's
   * langugage group.
   */
  const LangGroupFontPrefs* GetFontPrefsForLang(nsIAtom *aLanguage) const
  {
    nsIAtom* lang = aLanguage ? aLanguage : mLanguage.get();
    return StaticPresData::Get()->GetFontPrefsForLangHelper(lang, &mLangGroupFontPrefs);
  }

  void UpdateCharSet(const nsCString& aCharSet);

public:
  void DoChangeCharSet(const nsCString& aCharSet);

  /**
   * Checks for MozAfterPaint listeners on the document
   */
  bool MayHavePaintEventListener();

  /**
   * Checks for MozAfterPaint listeners on the document and
   * any subdocuments, except for subdocuments that are non-top-level
   * content documents.
   */
  bool MayHavePaintEventListenerInSubDocument();

#ifdef RESTYLE_LOGGING
  // Controls for whether debug information about restyling in this
  // document should be output.
  bool RestyleLoggingEnabled() const { return mRestyleLoggingEnabled; }
  void StartRestyleLogging() { mRestyleLoggingEnabled = true; }
  void StopRestyleLogging() { mRestyleLoggingEnabled = false; }
#endif

  void InvalidatePaintedLayers();

protected:
  // May be called multiple times (unlink, destructor)
  void Destroy();

  void AppUnitsPerDevPixelChanged();

  void HandleRebuildCounterStyles() {
    mPostedFlushCounterStyles = false;
    FlushCounterStyles();
  }

  bool HavePendingInputEvent();

  // Can't be inline because we can't include nsStyleSet.h.
  bool HasCachedStyleData();

  // Creates a one-shot timer with the given aCallback & aDelay.
  // Returns a refcounted pointer to the timer (or nullptr on failure).
  already_AddRefed<nsITimer> CreateTimer(nsTimerCallbackFunc aCallback,
                                         uint32_t aDelay);

  // IMPORTANT: The ownership implicit in the following member variables
  // has been explicitly checked.  If you add any members to this class,
  // please make the ownership explicit (pinkerton, scc).

  nsPresContextType     mType;
  // the nsPresShell owns a strong reference to the nsPresContext, and is responsible
  // for nulling this pointer before it is destroyed
  nsIPresShell* MOZ_NON_OWNING_REF mShell;         // [WEAK]
  nsCOMPtr<nsIDocument> mDocument;
  RefPtr<nsDeviceContext> mDeviceContext; // [STRONG] could be weak, but
                                            // better safe than sorry.
                                            // Cannot reintroduce cycles
                                            // since there is no dependency
                                            // from gfx back to layout.
  RefPtr<mozilla::EventStateManager> mEventManager;
  RefPtr<nsRefreshDriver> mRefreshDriver;
  RefPtr<mozilla::EffectCompositor> mEffectCompositor;
  RefPtr<nsTransitionManager> mTransitionManager;
  RefPtr<nsAnimationManager> mAnimationManager;
  mozilla::RestyleManagerHandle::RefPtr mRestyleManager;
  RefPtr<mozilla::CounterStyleManager> mCounterStyleManager;
  nsIAtom* MOZ_UNSAFE_REF("always a static atom") mMedium; // initialized by subclass ctors
  nsCOMPtr<nsIAtom> mMediaEmulated;

  // This pointer is nulled out through SetLinkHandler() in the destructors of
  // the classes which set it. (using SetLinkHandler() again).
  nsILinkHandler* MOZ_NON_OWNING_REF mLinkHandler;

  // Formerly mLangGroup; moving from charset-oriented langGroup to
  // maintaining actual language settings everywhere (see bug 524107).
  // This may in fact hold a langGroup such as x-western rather than
  // a specific language, however (e.g, if it is inferred from the
  // charset rather than explicitly specified as a lang attribute).
  nsCOMPtr<nsIAtom>     mLanguage;

public:
  // The following are public member variables so that we can use them
  // with mozilla::AutoToggle or mozilla::AutoRestore.

  // Should we disable font size inflation because we're inside of
  // shrink-wrapping calculations on an inflation container?
  bool                  mInflationDisabledForShrinkWrap;

protected:

  mozilla::WeakPtr<nsDocShell>             mContainer;

  // Base minimum font size, independent of the language-specific global preference. Defaults to 0
  int32_t               mBaseMinFontSize;
  float                 mTextZoom;      // Text zoom, defaults to 1.0
  float                 mFullZoom;      // Page zoom, defaults to 1.0
  float                 mOverrideDPPX;   // DPPX overrided, defaults to 0.0
  gfxSize               mLastFontInflationScreenSize;

  int32_t               mCurAppUnitsPerDevPixel;
  int32_t               mAutoQualityMinFontSizePixelsPref;

  nsCOMPtr<nsITheme> mTheme;
  nsCOMPtr<nsILanguageAtomService> mLangService;
  nsCOMPtr<nsIPrintSettings> mPrintSettings;
  nsCOMPtr<nsITimer>    mPrefChangedTimer;

  FramePropertyTable    mPropertyTable;

  nsInvalidateRequestList mInvalidateRequestsSinceLastPaint;
  nsInvalidateRequestList mUndeliveredInvalidateRequestsBeforeLastPaint;

  // text performance metrics
  nsAutoPtr<gfxTextPerfMetrics>   mTextPerf;

  nsAutoPtr<gfxMissingFontRecorder> mMissingFonts;

  nsRect                mVisibleArea;
  nsSize                mPageSize;
  float                 mPageScale;
  float                 mPPScale;

  nscolor               mDefaultColor;
  nscolor               mBackgroundColor;

  nscolor               mLinkColor;
  nscolor               mActiveLinkColor;
  nscolor               mVisitedLinkColor;

  nscolor               mFocusBackgroundColor;
  nscolor               mFocusTextColor;

  nscolor               mBodyTextColor;

  // This is a non-owning pointer. May be null. If non-null, it's guaranteed
  // to be pointing to a node that's still alive, because we'll reset it in
  // UpdateViewportScrollbarStylesOverride() as part of the cleanup code
  // when this node is removed from the document. (For <body> and the root node,
  // this call happens in nsCSSFrameConstructor::ContentRemoved(). For
  // fullscreen elements, it happens in the fullscreen-specific cleanup
  // invoked by Element::UnbindFromTree().)
  nsIContent* MOZ_NON_OWNING_REF mViewportScrollbarOverrideNode;
  ScrollbarStyles       mViewportStyleScrollbar;

  uint8_t               mFocusRingWidth;

  bool mExistThrottledUpdates;

  uint16_t              mImageAnimationMode;
  uint16_t              mImageAnimationModePref;

  // Most documents will only use one (or very few) language groups. Rather
  // than have the overhead of a hash lookup, we simply look along what will
  // typically be a very short (usually of length 1) linked list. There are 31
  // language groups, so in the worst case scenario we'll need to traverse 31
  // link items.
  LangGroupFontPrefs    mLangGroupFontPrefs;

  nscoord               mBorderWidthTable[3];

  uint32_t              mInterruptChecksToSkip;

  // Counters for tests and tools that want to detect frame construction
  // or reflow.
  uint64_t              mElementsRestyled;
  uint64_t              mFramesConstructed;
  uint64_t              mFramesReflowed;

  mozilla::TimeStamp    mReflowStartTime;

  // last time we did a full style flush
  mozilla::TimeStamp    mLastStyleUpdateForAllAnimations;

  unsigned              mHasPendingInterrupt : 1;
  unsigned              mPendingInterruptFromTest : 1;
  unsigned              mInterruptsEnabled : 1;
  unsigned              mUseDocumentFonts : 1;
  unsigned              mUseDocumentColors : 1;
  unsigned              mUnderlineLinks : 1;
  unsigned              mSendAfterPaintToContent : 1;
  unsigned              mUseFocusColors : 1;
  unsigned              mFocusRingOnAnything : 1;
  unsigned              mFocusRingStyle : 1;
  unsigned              mDrawImageBackground : 1;
  unsigned              mDrawColorBackground : 1;
  unsigned              mNeverAnimate : 1;
  unsigned              mIsRenderingOnlySelection : 1;
  unsigned              mPaginated : 1;
  unsigned              mCanPaginatedScroll : 1;
  unsigned              mDoScaledTwips : 1;
  unsigned              mIsRootPaginatedDocument : 1;
  unsigned              mPrefBidiDirection : 1;
  unsigned              mPrefScrollbarSide : 2;
  unsigned              mPendingSysColorChanged : 1;
  unsigned              mPendingThemeChanged : 1;
  unsigned              mPendingUIResolutionChanged : 1;
  unsigned              mPendingMediaFeatureValuesChanged : 1;
  unsigned              mPrefChangePendingNeedsReflow : 1;
  unsigned              mIsEmulatingMedia : 1;
  // True if the requests in mInvalidateRequestsSinceLastPaint cover the
  // entire viewport
  unsigned              mAllInvalidated : 1;

  // Are we currently drawing an SVG glyph?
  unsigned              mIsGlyph : 1;

  // Does the associated document use root-em (rem) units?
  unsigned              mUsesRootEMUnits : 1;
  // Does the associated document use ex or ch units?
  unsigned              mUsesExChUnits : 1;
  // Does the associated document use viewport units (vw/vh/vmin/vmax)?
  unsigned              mUsesViewportUnits : 1;

  // Has there been a change to the viewport's dimensions?
  unsigned              mPendingViewportChange : 1;

  // Is the current mCounterStyleManager valid?
  unsigned              mCounterStylesDirty : 1;
  // Do we currently have an event posted to call FlushCounterStyles?
  unsigned              mPostedFlushCounterStyles: 1;

  // resize reflow is suppressed when the only change has been to zoom
  // the document rather than to change the document's dimensions
  unsigned              mSuppressResizeReflow : 1;

  unsigned              mIsVisual : 1;

  unsigned              mFireAfterPaintEvents : 1;

  unsigned              mIsChrome : 1;
  unsigned              mIsChromeOriginImage : 1;

  // Should we paint flash in this context? Do not use this variable directly.
  // Use GetPaintFlashing() method instead.
  mutable unsigned mPaintFlashing : 1;
  mutable unsigned mPaintFlashingInitialized : 1;

  unsigned mHasWarnedAboutPositionedTableParts : 1;

  unsigned mHasWarnedAboutTooLargeDashedOrDottedRadius : 1;

  // Have we added quirk.css to the style set?
  unsigned              mQuirkSheetAdded : 1;

  // Is there a pref update to process once we have a container?
  unsigned              mNeedsPrefUpdate : 1;

  // Has NotifyNonBlankPaint been called on this PresContext?
  unsigned              mHadNonBlankPaint : 1;

#ifdef RESTYLE_LOGGING
  // Should we output debug information about restyling for this document?
  bool                  mRestyleLoggingEnabled;
#endif

#ifdef DEBUG
  bool                  mInitialized;
#endif


protected:

  virtual ~nsPresContext();

  nscolor MakeColorPref(const nsString& aColor);

  void LastRelease();

#ifdef DEBUG
private:
  friend struct nsAutoLayoutPhase;
  uint32_t mLayoutPhaseCount[eLayoutPhase_COUNT];
public:
  uint32_t LayoutPhaseCount(nsLayoutPhase aPhase) {
    return mLayoutPhaseCount[aPhase];
  }
#endif

};

class nsRootPresContext final : public nsPresContext {
public:
  nsRootPresContext(nsIDocument* aDocument, nsPresContextType aType);
  virtual ~nsRootPresContext();
  virtual void Detach() override;

  /**
   * Ensure that NotifyDidPaintForSubtree is eventually called on this
   * object after a timeout.
   */
  void EnsureEventualDidPaintEvent();

  void CancelDidPaintTimer()
  {
    if (mNotifyDidPaintTimer) {
      mNotifyDidPaintTimer->Cancel();
      mNotifyDidPaintTimer = nullptr;
    }
  }

  /**
   * Registers a plugin to receive geometry updates (position and clip
   * region) so it can update its widget.
   * Callers must call UnregisterPluginForGeometryUpdates before
   * the aPlugin frame is destroyed.
   */
  void RegisterPluginForGeometryUpdates(nsIContent* aPlugin);
  /**
   * Stops a plugin receiving geometry updates (position and clip
   * region). If the plugin was not already registered, this does
   * nothing.
   */
  void UnregisterPluginForGeometryUpdates(nsIContent* aPlugin);

  bool NeedToComputePluginGeometryUpdates()
  {
    return mRegisteredPlugins.Count() > 0;
  }
  /**
   * Compute geometry updates for each plugin given that aList is the display
   * list for aFrame. The updates are not yet applied;
   * ApplyPluginGeometryUpdates is responsible for that. In the meantime they
   * are stored on each nsPluginFrame.
   * This needs to be called even when aFrame is a popup, since although
   * windowed plugins aren't allowed in popups, windowless plugins are
   * and ComputePluginGeometryUpdates needs to be called for them.
   */
  void ComputePluginGeometryUpdates(nsIFrame* aFrame,
                                    nsDisplayListBuilder* aBuilder,
                                    nsDisplayList* aList);

  /**
   * Apply the stored plugin geometry updates. This should normally be called
   * in DidPaint so the plugins are moved/clipped immediately after we've
   * updated our window, so they look in sync with our window.
   */
  void ApplyPluginGeometryUpdates();

  /**
   * Transfer stored plugin geometry updates to the compositor. Called during
   * reflow, data is shipped over with layer updates. e10s specific.
   */
  void CollectPluginGeometryUpdates(mozilla::layers::LayerManager* aLayerManager);

  virtual bool IsRoot() override { return true; }

  /**
   * Increment DOM-modification generation counter to indicate that
   * the DOM has changed in a way that might lead to style changes/
   * reflows/frame creation and destruction.
   */
  void IncrementDOMGeneration() { mDOMGeneration++; }

  /**
   * Get the current DOM generation counter.
   *
   * See nsFrameManagerBase::GetGlobalGenerationNumber() for a
   * global generation number.
   */
  uint32_t GetDOMGeneration() { return mDOMGeneration; }

  /**
   * Add a runnable that will get called before the next paint. They will get
   * run eventually even if painting doesn't happen. They might run well before
   * painting happens.
   */
  void AddWillPaintObserver(nsIRunnable* aRunnable);

  /**
   * Run all runnables that need to get called before the next paint.
   */
  void FlushWillPaintObservers();

  virtual size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const override;

protected:
  /**
   * Start a timer to ensure we eventually run ApplyPluginGeometryUpdates.
   */
  void InitApplyPluginGeometryTimer();
  /**
   * Cancel the timer that ensures we eventually run ApplyPluginGeometryUpdates.
   */
  void CancelApplyPluginGeometryTimer();

  class RunWillPaintObservers : public mozilla::Runnable {
  public:
    explicit RunWillPaintObservers(nsRootPresContext* aPresContext) : mPresContext(aPresContext) {}
    void Revoke() { mPresContext = nullptr; }
    NS_IMETHOD Run() override
    {
      if (mPresContext) {
        mPresContext->FlushWillPaintObservers();
      }
      return NS_OK;
    }
    // The lifetime of this reference is handled by an nsRevocableEventPtr
    nsRootPresContext* MOZ_NON_OWNING_REF mPresContext;
  };

  friend class nsPresContext;

  nsCOMPtr<nsITimer> mNotifyDidPaintTimer;
  nsCOMPtr<nsITimer> mApplyPluginGeometryTimer;
  nsTHashtable<nsRefPtrHashKey<nsIContent> > mRegisteredPlugins;
  nsTArray<nsCOMPtr<nsIRunnable> > mWillPaintObservers;
  nsRevocableEventPtr<RunWillPaintObservers> mWillPaintFallbackEvent;
  uint32_t mDOMGeneration;
};

#ifdef MOZ_REFLOW_PERF

#define DO_GLOBAL_REFLOW_COUNT(_name) \
  aPresContext->CountReflows((_name), (nsIFrame*)this);
#else
#define DO_GLOBAL_REFLOW_COUNT(_name)
#endif // MOZ_REFLOW_PERF

#endif /* nsPresContext_h___ */