Revision control

Line Code
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
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
/* -*- 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/. */

#ifndef nsLayoutUtils_h__
#define nsLayoutUtils_h__

#include "mozilla/MemoryReporting.h"
#include "mozilla/ArrayUtils.h"
#include "mozilla/Maybe.h"
#include "mozilla/TypedEnumBits.h"
#include "nsBoundingMetrics.h"
#include "nsChangeHint.h"
#include "nsFrameList.h"
#include "mozilla/layout/FrameChildList.h"
#include "nsThreadUtils.h"
#include "nsIPrincipal.h"
#include "FrameMetrics.h"
#include "nsIWidget.h"
#include "nsCSSPropertyID.h"
#include "nsStyleCoord.h"
#include "nsStyleConsts.h"
#include "nsGkAtoms.h"
#include "nsRuleNode.h"
#include "imgIContainer.h"
#include "mozilla/gfx/2D.h"
#include "Units.h"
#include "mozilla/ToString.h"
#include "mozilla/ReflowOutput.h"
#include "ImageContainer.h"
#include "gfx2DGlue.h"
#include "nsStyleConsts.h"
#include "SVGImageContext.h"
#include <limits>
#include <algorithm>
#include "gfxPoint.h"

class gfxContext;
class nsPresContext;
class nsIContent;
class nsIAtom;
class nsIScrollableFrame;
class nsIDOMEvent;
class nsRegion;
class nsDisplayListBuilder;
enum class nsDisplayListBuilderMode : uint8_t;
class nsDisplayItem;
class nsFontMetrics;
class nsFontFaceList;
class nsIImageLoadingContent;
class nsStyleContext;
class nsBlockFrame;
class nsContainerFrame;
class nsView;
class nsIFrame;
class nsStyleCoord;
class nsStyleCorners;
class nsPIDOMWindowOuter;
class imgIRequest;
class nsIDocument;
struct nsStyleFont;
struct nsStyleImageOrientation;
struct nsOverflowAreas;

namespace mozilla {
enum class CSSPseudoElementType : uint8_t;
class EventListenerManager;
enum class LayoutFrameType : uint8_t;
struct IntrinsicSize;
struct ContainerLayerParameters;
class WritingMode;
class DisplayItemClip;
class EffectSet;
struct ActiveScrolledRoot;
namespace dom {
class CanvasRenderingContext2D;
class DOMRectList;
class Element;
class HTMLImageElement;
class HTMLCanvasElement;
class HTMLVideoElement;
class OffscreenCanvas;
class Selection;
} // namespace dom
namespace gfx {
struct RectCornerRadii;
enum class ShapedTextFlags : uint16_t;
} // namespace gfx
namespace layers {
class Image;
class Layer;
} // namespace layers
} // namespace mozilla

namespace mozilla {

struct DisplayPortPropertyData {
  DisplayPortPropertyData(const nsRect& aRect, uint32_t aPriority)
    : mRect(aRect)
    , mPriority(aPriority)
  {}
  nsRect mRect;
  uint32_t mPriority;
};

struct DisplayPortMarginsPropertyData {
  DisplayPortMarginsPropertyData(const ScreenMargin& aMargins,
                                 uint32_t aPriority)
    : mMargins(aMargins)
    , mPriority(aPriority)
  {}
  ScreenMargin mMargins;
  uint32_t mPriority;
};

} // namespace mozilla

// For GetDisplayPort
enum class RelativeTo {
  ScrollPort,
  ScrollFrame
};

// Flags to customize the behavior of nsLayoutUtils::DrawString.
enum class DrawStringFlags {
  eDefault         = 0x0,
  eForceHorizontal = 0x1 // Forces the text to be drawn horizontally.
};
MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(DrawStringFlags)

/**
 * nsLayoutUtils is a namespace class used for various helper
 * functions that are useful in multiple places in layout.  The goal
 * is not to define multiple copies of the same static helper.
 */
class nsLayoutUtils
{
  typedef mozilla::dom::DOMRectList DOMRectList;
  typedef mozilla::layers::Layer Layer;
  typedef mozilla::ContainerLayerParameters ContainerLayerParameters;
  typedef mozilla::IntrinsicSize IntrinsicSize;
  typedef mozilla::gfx::SourceSurface SourceSurface;
  typedef mozilla::gfx::Color Color;
  typedef mozilla::gfx::DrawTarget DrawTarget;
  typedef mozilla::gfx::ExtendMode ExtendMode;
  typedef mozilla::gfx::SamplingFilter SamplingFilter;
  typedef mozilla::gfx::Float Float;
  typedef mozilla::gfx::Point Point;
  typedef mozilla::gfx::Rect Rect;
  typedef mozilla::gfx::RectDouble RectDouble;
  typedef mozilla::gfx::Matrix4x4 Matrix4x4;
  typedef mozilla::gfx::RectCornerRadii RectCornerRadii;
  typedef mozilla::gfx::StrokeOptions StrokeOptions;
  typedef mozilla::image::DrawResult DrawResult;

public:
  typedef mozilla::layers::FrameMetrics FrameMetrics;
  typedef mozilla::layers::ScrollMetadata ScrollMetadata;
  typedef FrameMetrics::ViewID ViewID;
  typedef mozilla::CSSPoint CSSPoint;
  typedef mozilla::CSSSize CSSSize;
  typedef mozilla::CSSIntSize CSSIntSize;
  typedef mozilla::CSSRect CSSRect;
  typedef mozilla::ScreenMargin ScreenMargin;
  typedef mozilla::LayoutDeviceIntSize LayoutDeviceIntSize;
  typedef mozilla::StyleGeometryBox StyleGeometryBox;
  typedef mozilla::SVGImageContext SVGImageContext;

  /**
   * Finds previously assigned ViewID for the given content element, if any.
   * Returns whether a ViewID was previously assigned.
   */
  static bool FindIDFor(const nsIContent* aContent, ViewID* aOutViewId);

  /**
   * Finds previously assigned or generates a unique ViewID for the given
   * content element.
   */
  static ViewID FindOrCreateIDFor(nsIContent* aContent);

  /**
   * Find content for given ID.
   */
  static nsIContent* FindContentFor(ViewID aId);

  /**
   * Find the view ID (or generate a new one) for the content element
   * corresponding to the ASR.
   */
  static ViewID ViewIDForASR(const mozilla::ActiveScrolledRoot* aASR);

  /**
   * Find the scrollable frame for a given ID.
   */
  static nsIScrollableFrame* FindScrollableFrameFor(ViewID aId);

  /**
   * Find the ID for a given scrollable frame.
   */
  static ViewID FindIDForScrollableFrame(nsIScrollableFrame* aScrollable);

  /**
   * Get display port for the given element, relative to the specified entity,
   * defaulting to the scrollport.
   */
  static bool GetDisplayPort(nsIContent* aContent, nsRect *aResult,
    RelativeTo aRelativeTo = RelativeTo::ScrollPort);

  /**
   * Check whether the given element has a displayport.
   */
  static bool HasDisplayPort(nsIContent* aContent);

  /**
   * Check if the given element has a margins based displayport but is missing a
   * displayport base rect that it needs to properly compute a displayport rect.
   */
  static bool IsMissingDisplayPortBaseRect(nsIContent* aContent);

  /**
   * Go through the IPC Channel and update displayport margins for content
   * elements based on UpdateFrame messages. The messages are left in the
   * queue and will be fully processed when dequeued. The aim is to paint
   * the most up-to-date displayport without waiting for these message to
   * go through the message queue.
   */
  static void UpdateDisplayPortMarginsFromPendingMessages();

  /**
   * @return the display port for the given element which should be used for
   * visibility testing purposes.
   *
   * If low-precision buffers are enabled, this is the critical display port;
   * otherwise, it's the same display port returned by GetDisplayPort().
   */
  static bool GetDisplayPortForVisibilityTesting(
    nsIContent* aContent,
    nsRect* aResult,
    RelativeTo aRelativeTo = RelativeTo::ScrollPort);

  enum class RepaintMode : uint8_t {
    Repaint,
    DoNotRepaint
  };

  /**
   * Set the display port margins for a content element to be used with a
   * display port base (see SetDisplayPortBase()).
   * See also nsIDOMWindowUtils.setDisplayPortMargins.
   * @param aContent the content element for which to set the margins
   * @param aPresShell the pres shell for the document containing the element
   * @param aMargins the margins to set
   * @param aAlignmentX, alignmentY the amount of pixels to which to align the
   *                                displayport built by combining the base
   *                                rect with the margins, in either direction
   * @param aPriority a priority value to determine which margins take effect
   *                  when multiple callers specify margins
   * @param aRepaintMode whether to schedule a paint after setting the margins
   * @return true if the new margins were applied.
   */
  static bool SetDisplayPortMargins(nsIContent* aContent,
                                    nsIPresShell* aPresShell,
                                    const ScreenMargin& aMargins,
                                    uint32_t aPriority = 0,
                                    RepaintMode aRepaintMode = RepaintMode::Repaint);

  /**
   * Set the display port base rect for given element to be used with display
   * port margins.
   * SetDisplayPortBaseIfNotSet is like SetDisplayPortBase except it only sets
   * the display port base to aBase if no display port base is currently set.
   */
  static void SetDisplayPortBase(nsIContent* aContent, const nsRect& aBase);
  static void SetDisplayPortBaseIfNotSet(nsIContent* aContent, const nsRect& aBase);

  /**
   * Get the critical display port for the given element.
   */
  static bool GetCriticalDisplayPort(nsIContent* aContent, nsRect* aResult);

  /**
   * Check whether the given element has a critical display port.
   */
  static bool HasCriticalDisplayPort(nsIContent* aContent);

  /**
   * If low-precision painting is turned on, delegates to GetCriticalDisplayPort.
   * Otherwise, delegates to GetDisplayPort.
   */
  static bool GetHighResolutionDisplayPort(nsIContent* aContent, nsRect* aResult);

  /**
   * Remove the displayport for the given element.
   */
  static void RemoveDisplayPort(nsIContent* aContent);

  /**
   * Use heuristics to figure out the child list that
   * aChildFrame is currently in.
   */
  static mozilla::layout::FrameChildListID GetChildListNameFor(nsIFrame* aChildFrame);

  /**
   * Returns the ::before pseudo-element for aContent, if any.
   */
  static mozilla::dom::Element* GetBeforePseudo(const nsIContent* aContent);

  /**
   * Returns the frame corresponding to the ::before pseudo-element for
   * aContent, if any.
   */
  static nsIFrame* GetBeforeFrame(const nsIContent* aContent);

  /**
   * Returns the ::after pseudo-element for aContent, if any.
   */
  static mozilla::dom::Element* GetAfterPseudo(const nsIContent* aContent);

  /**
   * Returns the frame corresponding to the ::after pseudo-element for aContent,
   * if any.
   */
  static nsIFrame* GetAfterFrame(const nsIContent* aContent);

  /**
   * Given a frame, search up the frame tree until we find an
   * ancestor that (or the frame itself) is of type aFrameType, if any.
   *
   * @param aFrame the frame to start at
   * @param aFrameType the frame type to look for
   * @param aStopAt a frame to stop at after we checked it
   * @return a frame of the given type or nullptr if no
   *         such ancestor exists
   */
  static nsIFrame* GetClosestFrameOfType(nsIFrame* aFrame,
                                         mozilla::LayoutFrameType aFrameType,
                                         nsIFrame* aStopAt = nullptr);

  /**
   * Given a frame, search up the frame tree until we find an
   * ancestor that (or the frame itself) is a "Page" frame, if any.
   *
   * @param aFrame the frame to start at
   * @return a frame of type mozilla::LayoutFrameType::Page or nullptr if no
   *         such ancestor exists
   */
  static nsIFrame* GetPageFrame(nsIFrame* aFrame);

  /**
   * Given a frame which is the primary frame for an element,
   * return the frame that has the non-pseudoelement style context for
   * the content.
   * This is aPrimaryFrame itself except for tableWrapper frames.
   *
   * Given a non-null input, this will return null if and only if its
   * argument is a table wrapper frame that is mid-destruction (and its
   * table frame has been destroyed).
   */
  static nsIFrame* GetStyleFrame(nsIFrame* aPrimaryFrame);

  /**
   * Given a content node,
   * return the frame that has the non-pseudoelement style context for
   * the content.  May return null.
   * This is aContent->GetPrimaryFrame() except for tableWrapper frames.
   */
  static nsIFrame* GetStyleFrame(const nsIContent* aContent);

  /**
   * Gets the real primary frame associated with the content object.
   *
   * In the case of absolutely positioned elements and floated elements,
   * the real primary frame is the frame that is out of the flow and not the
   * placeholder frame.
   */
  static nsIFrame* GetRealPrimaryFrameFor(const nsIContent* aContent);

  /**
   * IsGeneratedContentFor returns true if aFrame is the outermost
   * frame for generated content of type aPseudoElement for aContent.
   * aFrame *might not* have the aPseudoElement pseudo-style! For example
   * it might be a table wrapper frame and the inner table frame might
   * have the pseudo-style.
   *
   * @param aContent the content node we're looking at.  If this is
   *        null, then we just assume that aFrame has the right content
   *        pointer.
   * @param aFrame the frame we're looking at
   * @param aPseudoElement the pseudo type we're interested in
   * @return whether aFrame is the generated aPseudoElement frame for aContent
   */
  static bool IsGeneratedContentFor(nsIContent* aContent, nsIFrame* aFrame,
                                      nsIAtom* aPseudoElement);

#ifdef DEBUG
  // TODO: remove, see bug 598468.
  static bool gPreventAssertInCompareTreePosition;
#endif // DEBUG

  /**
   * CompareTreePosition determines whether aContent1 comes before or
   * after aContent2 in a preorder traversal of the content tree.
   *
   * @param aCommonAncestor either null, or a common ancestor of
   *                        aContent1 and aContent2.  Actually this is
   *                        only a hint; if it's not an ancestor of
   *                        aContent1 or aContent2, this function will
   *                        still work, but it will be slower than
   *                        normal.
   * @return < 0 if aContent1 is before aContent2
   *         > 0 if aContent1 is after aContent2,
   *         0 otherwise (meaning they're the same, or they're in
   *           different documents)
   */
  static int32_t CompareTreePosition(nsIContent* aContent1,
                                     nsIContent* aContent2,
                                     const nsIContent* aCommonAncestor = nullptr)
  {
    return DoCompareTreePosition(aContent1, aContent2, -1, 1, aCommonAncestor);
  }

  /*
   * More generic version of |CompareTreePosition|.  |aIf1Ancestor|
   * gives the value to return when 1 is an ancestor of 2, and likewise
   * for |aIf2Ancestor|.  Passing (-1, 1) gives preorder traversal
   * order, and (1, -1) gives postorder traversal order.
   */
  static int32_t DoCompareTreePosition(nsIContent* aContent1,
                                       nsIContent* aContent2,
                                       int32_t aIf1Ancestor,
                                       int32_t aIf2Ancestor,
                                       const nsIContent* aCommonAncestor = nullptr);

  /**
   * CompareTreePosition determines whether aFrame1 comes before or
   * after aFrame2 in a preorder traversal of the frame tree, where out
   * of flow frames are treated as children of their placeholders. This is
   * basically the same ordering as DoCompareTreePosition(nsIContent*) except
   * that it handles anonymous content properly and there are subtleties with
   * continuations.
   *
   * @param aCommonAncestor either null, or a common ancestor of
   *                        aContent1 and aContent2.  Actually this is
   *                        only a hint; if it's not an ancestor of
   *                        aContent1 or aContent2, this function will
   *                        still work, but it will be slower than
   *                        normal.
   * @return < 0 if aContent1 is before aContent2
   *         > 0 if aContent1 is after aContent2,
   *         0 otherwise (meaning they're the same, or they're in
   *           different frame trees)
   */
  static int32_t CompareTreePosition(nsIFrame* aFrame1,
                                     nsIFrame* aFrame2,
                                     nsIFrame* aCommonAncestor = nullptr)
  {
    return DoCompareTreePosition(aFrame1, aFrame2, -1, 1, aCommonAncestor);
  }

  static int32_t CompareTreePosition(nsIFrame* aFrame1,
                                     nsIFrame* aFrame2,
                                     nsTArray<nsIFrame*>& aFrame2Ancestors,
                                     nsIFrame* aCommonAncestor = nullptr)
  {
    return DoCompareTreePosition(aFrame1, aFrame2, aFrame2Ancestors,
                                 -1, 1, aCommonAncestor);
  }

  /*
   * More generic version of |CompareTreePosition|.  |aIf1Ancestor|
   * gives the value to return when 1 is an ancestor of 2, and likewise
   * for |aIf2Ancestor|.  Passing (-1, 1) gives preorder traversal
   * order, and (1, -1) gives postorder traversal order.
   */
  static int32_t DoCompareTreePosition(nsIFrame* aFrame1,
                                       nsIFrame* aFrame2,
                                       int32_t aIf1Ancestor,
                                       int32_t aIf2Ancestor,
                                       nsIFrame* aCommonAncestor = nullptr);

  static nsIFrame* FillAncestors(nsIFrame* aFrame,
                                 nsIFrame* aStopAtAncestor,
                                 nsTArray<nsIFrame*>* aAncestors);

  static int32_t DoCompareTreePosition(nsIFrame* aFrame1,
                                       nsIFrame* aFrame2,
                                       nsTArray<nsIFrame*>& aFrame2Ancestors,
                                       int32_t aIf1Ancestor,
                                       int32_t aIf2Ancestor,
                                       nsIFrame* aCommonAncestor);

  /**
   * LastContinuationWithChild gets the last continuation in aFrame's chain
   * that has a child, or the first continuation if the frame has no children.
   */
  static nsContainerFrame* LastContinuationWithChild(nsContainerFrame* aFrame);

  /**
   * GetLastSibling simply finds the last sibling of aFrame, or returns nullptr if
   * aFrame is null.
   */
  static nsIFrame* GetLastSibling(nsIFrame* aFrame);

  /**
   * FindSiblingViewFor locates the child of aParentView that aFrame's
   * view should be inserted 'above' (i.e., before in sibling view
   * order).  This is the first child view of aParentView whose
   * corresponding content is before aFrame's content (view siblings
   * are in reverse content order).
   */
  static nsView* FindSiblingViewFor(nsView* aParentView, nsIFrame* aFrame);

  /**
   * Get the parent of aFrame. If aFrame is the root frame for a document,
   * and the document has a parent document in the same view hierarchy, then
   * we try to return the subdocumentframe in the parent document.
   * @param aExtraOffset [in/out] if non-null, then as we cross documents
   * an extra offset may be required and it will be added to aCrossDocOffset.
   * Be careful dealing with this extra offset as it is in app units of the
   * parent document, which may have a different app units per dev pixel ratio
   * than the child document.
   */
  static nsIFrame* GetCrossDocParentFrame(const nsIFrame* aFrame,
                                          nsPoint* aCrossDocOffset = nullptr);

  /**
   * IsProperAncestorFrame checks whether aAncestorFrame is an ancestor
   * of aFrame and not equal to aFrame.
   * @param aCommonAncestor nullptr, or a common ancestor of aFrame and
   * aAncestorFrame. If non-null, this can bound the search and speed up
   * the function
   */
  static bool IsProperAncestorFrame(nsIFrame* aAncestorFrame, nsIFrame* aFrame,
                                      nsIFrame* aCommonAncestor = nullptr);

  /**
   * Like IsProperAncestorFrame, but looks across document boundaries.
   *
   * Just like IsAncestorFrameCrossDoc, except that it returns false when
   * aFrame == aAncestorFrame.
   */
  static bool IsProperAncestorFrameCrossDoc(nsIFrame* aAncestorFrame, nsIFrame* aFrame,
                                              nsIFrame* aCommonAncestor = nullptr);

  /**
   * IsAncestorFrameCrossDoc checks whether aAncestorFrame is an ancestor
   * of aFrame or equal to aFrame, looking across document boundaries.
   * @param aCommonAncestor nullptr, or a common ancestor of aFrame and
   * aAncestorFrame. If non-null, this can bound the search and speed up
   * the function.
   *
   * Just like IsProperAncestorFrameCrossDoc, except that it returns true when
   * aFrame == aAncestorFrame.
   */
  static bool IsAncestorFrameCrossDoc(const nsIFrame* aAncestorFrame, const nsIFrame* aFrame,
                                        const nsIFrame* aCommonAncestor = nullptr);

  /**
   * Sets the fixed-pos metadata properties on aLayer.
   * aAnchorRect is the basic anchor rectangle. If aFixedPosFrame is not a viewport
   * frame, then we pick a corner of aAnchorRect to as the anchor point for the
   * fixed-pos layer (i.e. the point to remain stable during zooming), based
   * on which of the fixed-pos frame's CSS absolute positioning offset
   * properties (top, left, right, bottom) are auto. aAnchorRect is in the
   * coordinate space of aLayer's container layer (i.e. relative to the reference
   * frame of the display item which is building aLayer's container layer).
   */
  static void SetFixedPositionLayerData(Layer* aLayer, const nsIFrame* aViewportFrame,
                                        const nsRect& aAnchorRect,
                                        const nsIFrame* aFixedPosFrame,
                                        nsPresContext* aPresContext,
                                        const ContainerLayerParameters& aContainerParameters);

  /**
   * Return true if aPresContext's viewport has a displayport.
   */
  static bool ViewportHasDisplayPort(nsPresContext* aPresContext);

  /**
   * Return true if aFrame is a fixed-pos frame and is a child of a viewport
   * which has a displayport. These frames get special treatment from the compositor.
   * aDisplayPort, if non-null, is set to the display port rectangle (relative to
   * the viewport).
   */
  static bool IsFixedPosFrameInDisplayPort(const nsIFrame* aFrame);

  /**
   * Store whether aThumbFrame wants its own layer. This sets a property on
   * the frame.
   */
  static void SetScrollbarThumbLayerization(nsIFrame* aThumbFrame, bool aLayerize);

  /**
   * Returns whether aThumbFrame wants its own layer due to having called
   * SetScrollbarThumbLayerization.
   */
  static bool IsScrollbarThumbLayerized(nsIFrame* aThumbFrame);

  /**
    * GetScrollableFrameFor returns the scrollable frame for a scrolled frame
    */
  static nsIScrollableFrame* GetScrollableFrameFor(const nsIFrame *aScrolledFrame);

  /**
   * GetNearestScrollableFrameForDirection locates the first ancestor of
   * aFrame (or aFrame itself) that is scrollable with overflow:scroll or
   * overflow:auto in the given direction and where either the scrollbar for
   * that direction is visible or the frame can be scrolled by some
   * positive amount in that direction.
   * The search extends across document boundaries.
   *
   * @param  aFrame the frame to start with
   * @param  aDirection Whether it's for horizontal or vertical scrolling.
   * @return the nearest scrollable frame or nullptr if not found
   */
  enum Direction { eHorizontal, eVertical };
  static nsIScrollableFrame* GetNearestScrollableFrameForDirection(nsIFrame* aFrame,
                                                                   Direction aDirection);

  enum {
    /**
     * If the SCROLLABLE_SAME_DOC flag is set, then we only walk the frame tree
     * up to the root frame in the current document.
     */
    SCROLLABLE_SAME_DOC = 0x01,
    /**
     * If the SCROLLABLE_INCLUDE_HIDDEN flag is set then we allow
     * overflow:hidden scrollframes to be returned as scrollable frames.
     */
    SCROLLABLE_INCLUDE_HIDDEN = 0x02,
    /**
     * If the SCROLLABLE_ONLY_ASYNC_SCROLLABLE flag is set, then we only
     * want to match scrollable frames for which WantAsyncScroll() returns
     * true.
     */
    SCROLLABLE_ONLY_ASYNC_SCROLLABLE = 0x04,
    /**
     * If the SCROLLABLE_ALWAYS_MATCH_ROOT flag is set, then we will always
     * return the root scrollable frame for the root document (in the current
     * process) if we encounter it, whether or not it is async scrollable or
     * overflow: hidden.
     */
    SCROLLABLE_ALWAYS_MATCH_ROOT = 0x08,
    /**
     * If the SCROLLABLE_FIXEDPOS_FINDS_ROOT flag is set, then for fixed-pos
     * frames that are in the root document (in the current process) return the
     * root scrollable frame for that document.
     */
    SCROLLABLE_FIXEDPOS_FINDS_ROOT = 0x10
  };
  /**
   * GetNearestScrollableFrame locates the first ancestor of aFrame
   * (or aFrame itself) that is scrollable with overflow:scroll or
   * overflow:auto in some direction.
   *
   * @param  aFrame the frame to start with
   * @param  aFlags if SCROLLABLE_SAME_DOC is set, do not search across
   * document boundaries. If SCROLLABLE_INCLUDE_HIDDEN is set, include
   * frames scrollable with overflow:hidden.
   * @return the nearest scrollable frame or nullptr if not found
   */
  static nsIScrollableFrame* GetNearestScrollableFrame(nsIFrame* aFrame,
                                                       uint32_t aFlags = 0);

  /**
   * GetScrolledRect returns the range of allowable scroll offsets
   * for aScrolledFrame, assuming the scrollable overflow area is
   * aScrolledFrameOverflowArea and the scrollport size is aScrollPortSize.
   * aDirection is either NS_STYLE_DIRECTION_LTR or NS_STYLE_DIRECTION_RTL.
   */
  static nsRect GetScrolledRect(nsIFrame* aScrolledFrame,
                                const nsRect& aScrolledFrameOverflowArea,
                                const nsSize& aScrollPortSize,
                                uint8_t aDirection);

  /**
   * HasPseudoStyle returns true if aContent (whose primary style
   * context is aStyleContext) has the aPseudoElement pseudo-style
   * attached to it; returns false otherwise.
   *
   * @param aContent the content node we're looking at
   * @param aStyleContext aContent's style context
   * @param aPseudoElement the id of the pseudo style we care about
   * @param aPresContext the presentation context
   * @return whether aContent has aPseudoElement style attached to it
   */
  static bool HasPseudoStyle(nsIContent* aContent,
                               nsStyleContext* aStyleContext,
                               mozilla::CSSPseudoElementType aPseudoElement,
                               nsPresContext* aPresContext);

  /**
   * If this frame is a placeholder for a float, then return the float,
   * otherwise return nullptr.  aPlaceholder must be a placeholder frame.
   */
  static nsIFrame* GetFloatFromPlaceholder(nsIFrame* aPlaceholder);

  // Combine aNewBreakType with aOrigBreakType, but limit the break types
  // to StyleClear::Left, Right, Both.
  static mozilla::StyleClear CombineBreakType(mozilla::StyleClear aOrigBreakType,
                                              mozilla::StyleClear aNewBreakType);

  /**
   * Get the coordinates of a given DOM mouse event, relative to a given
   * frame. Works only for DOM events generated by WidgetGUIEvents.
   * @param aDOMEvent the event
   * @param aFrame the frame to make coordinates relative to
   * @return the point, or (NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE) if
   * for some reason the coordinates for the mouse are not known (e.g.,
   * the event is not a GUI event).
   */
  static nsPoint GetDOMEventCoordinatesRelativeTo(nsIDOMEvent* aDOMEvent,
                                                  nsIFrame* aFrame);

  /**
   * Get the coordinates of a given native mouse event, relative to a given
   * frame.
   * @param aEvent the event
   * @param aFrame the frame to make coordinates relative to
   * @return the point, or (NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE) if
   * for some reason the coordinates for the mouse are not known (e.g.,
   * the event is not a GUI event).
   */
  static nsPoint GetEventCoordinatesRelativeTo(
                   const mozilla::WidgetEvent* aEvent,
                   nsIFrame* aFrame);

  /**
   * Get the coordinates of a given point relative to an event and a
   * given frame.
   * @param aEvent the event
   * @param aPoint the point to get the coordinates relative to
   * @param aFrame the frame to make coordinates relative to
   * @return the point, or (NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE) if
   * for some reason the coordinates for the mouse are not known (e.g.,
   * the event is not a GUI event).
   */
  static nsPoint GetEventCoordinatesRelativeTo(
                   const mozilla::WidgetEvent* aEvent,
                   const mozilla::LayoutDeviceIntPoint& aPoint,
                   nsIFrame* aFrame);

  /**
   * Get the coordinates of a given point relative to a widget and a
   * given frame.
   * @param aWidget the event src widget
   * @param aPoint the point to get the coordinates relative to
   * @param aFrame the frame to make coordinates relative to
   * @return the point, or (NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE) if
   * for some reason the coordinates for the mouse are not known (e.g.,
   * the event is not a GUI event).
   */
  static nsPoint GetEventCoordinatesRelativeTo(nsIWidget* aWidget,
                                               const mozilla::LayoutDeviceIntPoint& aPoint,
                                               nsIFrame* aFrame);

  /**
   * Get the popup frame of a given native mouse event.
   * @param aPresContext only check popups within aPresContext or a descendant
   * @param aEvent  the event.
   * @return        Null, if there is no popup frame at the point, otherwise,
   *                returns top-most popup frame at the point.
   */
  static nsIFrame* GetPopupFrameForEventCoordinates(
                     nsPresContext* aPresContext,
                     const mozilla::WidgetEvent* aEvent);

  /**
   * Translate from widget coordinates to the view's coordinates
   * @param aPresContext the PresContext for the view
   * @param aWidget the widget
   * @param aPt the point relative to the widget
   * @param aView  view to which returned coordinates are relative
   * @return the point in the view's coordinates
   */
  static nsPoint TranslateWidgetToView(nsPresContext* aPresContext,
                                       nsIWidget* aWidget,
                                       const mozilla::LayoutDeviceIntPoint& aPt,
                                       nsView* aView);

  /**
   * Translate from view coordinates to the widget's coordinates.
   * @param aPresContext the PresContext for the view
   * @param aView the view
   * @param aPt the point relative to the view
   * @param aWidget the widget to which returned coordinates are relative
   * @return the point in the view's coordinates
   */
  static mozilla::LayoutDeviceIntPoint
    TranslateViewToWidget(nsPresContext* aPresContext,
                          nsView* aView, nsPoint aPt,
                          nsIWidget* aWidget);

  static mozilla::LayoutDeviceIntPoint
    WidgetToWidgetOffset(nsIWidget* aFromWidget, nsIWidget* aToWidget);

  enum FrameForPointFlags {
    /**
     * When set, paint suppression is ignored, so we'll return non-root page
     * elements even if paint suppression is stopping them from painting.
     */
    IGNORE_PAINT_SUPPRESSION = 0x01,
    /**
     * When set, clipping due to the root scroll frame (and any other viewport-
     * related clipping) is ignored.
     */
    IGNORE_ROOT_SCROLL_FRAME = 0x02,
    /**
     * When set, return only content in the same document as aFrame.
     */
    IGNORE_CROSS_DOC = 0x04,
    /**
     * When set, return only content that is actually visible.
     */
    ONLY_VISIBLE = 0x08
  };

  /**
   * Given aFrame, the root frame of a stacking context, find its descendant
   * frame under the point aPt that receives a mouse event at that location,
   * or nullptr if there is no such frame.
   * @param aPt the point, relative to the frame origin
   * @param aFlags some combination of FrameForPointFlags
   */
  static nsIFrame* GetFrameForPoint(nsIFrame* aFrame, nsPoint aPt,
                                    uint32_t aFlags = 0);

  /**
   * Given aFrame, the root frame of a stacking context, find all descendant
   * frames under the area of a rectangle that receives a mouse event,
   * or nullptr if there is no such frame.
   * @param aRect the rect, relative to the frame origin
   * @param aOutFrames an array to add all the frames found
   * @param aFlags some combination of FrameForPointFlags
   */
  static nsresult GetFramesForArea(nsIFrame* aFrame, const nsRect& aRect,
                                   nsTArray<nsIFrame*> &aOutFrames,
                                   uint32_t aFlags = 0);

  /**
   * Transform aRect relative to aFrame up to the coordinate system of
   * aAncestor. Computes the bounding-box of the true quadrilateral.
   * Pass non-null aPreservesAxisAlignedRectangles and it will be set to true if
   * we only need to use a 2d transform that PreservesAxisAlignedRectangles().
   *
   * |aMatrixCache| allows for optimizations in recomputing the same matrix over
   * and over. The argument can be one of the following values:
   * nullptr (the default) - No optimization; the transform matrix is computed on
   *   every call to this function.
   * non-null pointer to an empty Maybe<Matrix4x4> - Upon return, the Maybe is
   *   filled with the transform matrix that was computed. This can then be passed
   *   in to subsequent calls with the same source and destination frames to avoid
   *   recomputing the matrix.
   * non-null pointer to a non-empty Matrix4x4 - The provided matrix will be used
   *   as the transform matrix and applied to the rect.
   */
  static nsRect TransformFrameRectToAncestor(nsIFrame* aFrame,
                                             const nsRect& aRect,
                                             const nsIFrame* aAncestor,
                                             bool* aPreservesAxisAlignedRectangles = nullptr,
                                             mozilla::Maybe<Matrix4x4>* aMatrixCache = nullptr);


  /**
   * Gets the transform for aFrame relative to aAncestor. Pass null for
   * aAncestor to go up to the root frame. aInCSSUnits set to true will
   * return CSS units, set to false (the default) will return App units.
   */
  static Matrix4x4 GetTransformToAncestor(nsIFrame *aFrame,
                                          const nsIFrame *aAncestor,
                                          bool aInCSSUnits = false);

  /**
   * Gets the scale factors of the transform for aFrame relative to the root
   * frame if this transform is 2D, or the identity scale factors otherwise.
   */
  static gfxSize GetTransformToAncestorScale(nsIFrame* aFrame);

  /**
   * Gets the scale factors of the transform for aFrame relative to the root
   * frame if this transform is 2D, or the identity scale factors otherwise.
   * If some frame on the path from aFrame to the display root frame may have an
   * animated scale, returns the identity scale factors.
   */
  static gfxSize GetTransformToAncestorScaleExcludingAnimated(nsIFrame* aFrame);

  /**
   * Find the nearest common ancestor frame for aFrame1 and aFrame2. The
   * ancestor frame could be cross-doc.
   */
  static nsIFrame* FindNearestCommonAncestorFrame(nsIFrame* aFrame1,
                                                  nsIFrame* aFrame2);

  /**
   * Transforms a list of CSSPoints from aFromFrame to aToFrame, taking into
   * account all relevant transformations on the frames up to (but excluding)
   * their nearest common ancestor.
   * If we encounter a transform that we need to invert but which is
   * non-invertible, we return NONINVERTIBLE_TRANSFORM. If the frames have
   * no common ancestor, we return NO_COMMON_ANCESTOR.
   * If this returns TRANSFORM_SUCCEEDED, the points in aPoints are transformed
   * in-place, otherwise they are untouched.
   */
  enum TransformResult {
    TRANSFORM_SUCCEEDED,
    NO_COMMON_ANCESTOR,
    NONINVERTIBLE_TRANSFORM
  };
  static TransformResult TransformPoints(nsIFrame* aFromFrame, nsIFrame* aToFrame,
                                         uint32_t aPointCount, CSSPoint* aPoints);

  /**
   * Same as above function, but transform points in app units and
   * handle 1 point per call.
   */
  static TransformResult TransformPoint(nsIFrame* aFromFrame, nsIFrame* aToFrame,
                                        nsPoint& aPoint);

  /**
   * Transforms a rect from aFromFrame to aToFrame. In app units.
   * Returns the bounds of the actual rect if the transform requires rotation
   * or anything complex like that.
   */
  static TransformResult TransformRect(nsIFrame* aFromFrame, nsIFrame* aToFrame,
                                       nsRect& aRect);

  /**
   * Converts app units to pixels (with optional snapping) and appends as a
   * translation to aTransform.
   */
  static void PostTranslate(Matrix4x4& aTransform, const nsPoint& aOrigin, float aAppUnitsPerPixel, bool aRounded);

  /**
   * Get the border-box of aElement's primary frame, transformed it to be
   * relative to aFrame.
   */
  static nsRect GetRectRelativeToFrame(mozilla::dom::Element* aElement,
                                       nsIFrame* aFrame);

  /**
   * Returns true if aRect with border inflation of size aInflateSize contains
   * aPoint.
   */
  static bool ContainsPoint(const nsRect& aRect, const nsPoint& aPoint,
                            nscoord aInflateSize);

  /**
   * Clamp aRect relative to aFrame to the scroll frames boundary searching from
   * aFrame.
   */
  static nsRect ClampRectToScrollFrames(nsIFrame* aFrame,
                                        const nsRect& aRect);

  /**
   * Return true if a "layer transform" could be computed for aFrame,
   * and optionally return the computed transform.  The returned
   * transform is what would be set on the layer currently if a layers
   * transaction were opened at the time this helper is called.
   */
  static bool GetLayerTransformForFrame(nsIFrame* aFrame,
                                        Matrix4x4* aTransform);

  /**
   * Given a point in the global coordinate space, returns that point expressed
   * in the coordinate system of aFrame.  This effectively inverts all
   * transforms between this point and the root frame.
   *
   * @param aFrame The frame that acts as the coordinate space container.
   * @param aPoint The point, in the global space, to get in the frame-local space.
   * @return aPoint, expressed in aFrame's canonical coordinate space.
   */
  static nsPoint TransformRootPointToFrame(nsIFrame* aFrame,
                                           const nsPoint &aPoint)
  {
    return TransformAncestorPointToFrame(aFrame, aPoint, nullptr);
  }

  /**
   * Transform aPoint relative to aAncestor down to the coordinate system of
   * aFrame.
   */
  static nsPoint TransformAncestorPointToFrame(nsIFrame* aFrame,
                                               const nsPoint& aPoint,
                                               nsIFrame* aAncestor);

  /**
   * Helper function that, given a rectangle and a matrix, returns the smallest
   * rectangle containing the image of the source rectangle.
   *
   * @param aBounds The rectangle to transform.
   * @param aMatrix The matrix to transform it with.
   * @param aFactor The number of app units per graphics unit.
   * @return The smallest rect that contains the image of aBounds.
   */
  static nsRect MatrixTransformRect(const nsRect &aBounds,
                                    const Matrix4x4 &aMatrix, float aFactor);

  /**
   * Helper function that, given a point and a matrix, returns the image
   * of that point under the matrix transform.
   *
   * @param aPoint The point to transform.
   * @param aMatrix The matrix to transform it with.
   * @param aFactor The number of app units per graphics unit.
   * @return The image of the point under the transform.
   */
  static nsPoint MatrixTransformPoint(const nsPoint &aPoint,
                                      const Matrix4x4 &aMatrix, float aFactor);

  /**
   * Given a graphics rectangle in graphics space, return a rectangle in
   * app space that contains the graphics rectangle, rounding out as necessary.
   *
   * @param aRect The graphics rect to round outward.
   * @param aFactor The number of app units per graphics unit.
   * @return The smallest rectangle in app space that contains aRect.
   */
  static nsRect RoundGfxRectToAppRect(const Rect &aRect, float aFactor);

  /**
   * Given a graphics rectangle in graphics space, return a rectangle in
   * app space that contains the graphics rectangle, rounding out as necessary.
   *
   * @param aRect The graphics rect to round outward.
   * @param aFactor The number of app units per graphics unit.
   * @return The smallest rectangle in app space that contains aRect.
   */
  static nsRect RoundGfxRectToAppRect(const gfxRect &aRect, float aFactor);

  /**
   * Returns a subrectangle of aContainedRect that is entirely inside the rounded
   * rect. Complex cases are handled conservatively by returning a smaller
   * rect than necessary.
   */
  static nsRegion RoundedRectIntersectRect(const nsRect& aRoundedRect,
                                           const nscoord aRadii[8],
                                           const nsRect& aContainedRect);
  static nsIntRegion RoundedRectIntersectIntRect(const nsIntRect& aRoundedRect,
                                                 const RectCornerRadii& aCornerRadii,
                                                 const nsIntRect& aContainedRect);

  /**
   * Return whether any part of aTestRect is inside of the rounded
   * rectangle formed by aBounds and aRadii (which are indexed by the
   * enum HalfCorner constants in gfx/2d/Types.h). This is precise.
   */
  static bool RoundedRectIntersectsRect(const nsRect& aRoundedRect,
                                        const nscoord aRadii[8],
                                        const nsRect& aTestRect);

  enum class PaintFrameFlags : uint32_t {
    PAINT_IN_TRANSFORM = 0x01,
    PAINT_SYNC_DECODE_IMAGES = 0x02,
    PAINT_WIDGET_LAYERS = 0x04,
    PAINT_IGNORE_SUPPRESSION = 0x08,
    PAINT_DOCUMENT_RELATIVE = 0x10,
    PAINT_HIDE_CARET = 0x20,
    PAINT_TO_WINDOW = 0x40,
    PAINT_EXISTING_TRANSACTION = 0x80,
    PAINT_NO_COMPOSITE = 0x100,
    PAINT_COMPRESSED = 0x200
  };

  /**
   * Given aFrame, the root frame of a stacking context, paint it and its
   * descendants to aRenderingContext.
   * @param aRenderingContext a rendering context translated so that (0,0)
   * is the origin of aFrame; for best results, (0,0) should transform
   * to pixel-aligned coordinates. This can be null, in which case
   * aFrame must be a "display root" (root frame for a root document,
   * or the root of a popup) with an associated widget and we draw using
   * the layer manager for the frame's widget.
   * @param aDirtyRegion the region that must be painted, in the coordinates
   * of aFrame.
   * @param aBackstop paint the dirty area with this color before drawing
   * the actual content; pass NS_RGBA(0,0,0,0) to draw no background.
   * @param aBuilderMode Passed through to the display-list builder.
   * @param aFlags if PAINT_IN_TRANSFORM is set, then we assume
   * this is inside a transform or SVG foreignObject. If
   * PAINT_SYNC_DECODE_IMAGES is set, we force synchronous decode on all
   * images. If PAINT_WIDGET_LAYERS is set, aFrame must be a display root,
   * and we will use the frame's widget's layer manager to paint
   * even if aRenderingContext is non-null. This is useful if you want
   * to force rendering to use the widget's layer manager for testing
   * or speed. PAINT_WIDGET_LAYERS must be set if aRenderingContext is null.
   * If PAINT_DOCUMENT_RELATIVE is used, the visible region is interpreted
   * as being relative to the document (normally it's relative to the CSS
   * viewport) and the document is painted as if no scrolling has occured.
   * Only considered if nsIPresShell::IgnoringViewportScrolling is true.
   * PAINT_TO_WINDOW sets painting to window to true on the display list
   * builder even if we can't tell that we are painting to the window.
   * If PAINT_EXISTING_TRANSACTION is set, then BeginTransaction() has already
   * been called on aFrame's widget's layer manager and should not be
   * called again.
   * If PAINT_COMPRESSED is set, the FrameLayerBuilder should be set to
   * compressed mode to avoid short cut optimizations.
   *
   * So there are three possible behaviours:
   * 1) PAINT_WIDGET_LAYERS is set and aRenderingContext is null; we paint
   * by calling BeginTransaction on the widget's layer manager.
   * 2) PAINT_WIDGET_LAYERS is set and aRenderingContext is non-null; we
   * paint by calling BeginTransactionWithTarget on the widget's layer
   * manager.
   * 3) PAINT_WIDGET_LAYERS is not set and aRenderingContext is non-null;
   * we paint by construct a BasicLayerManager and calling
   * BeginTransactionWithTarget on it. This is desirable if we're doing
   * something like drawWindow in a mode where what gets rendered doesn't
   * necessarily correspond to what's visible in the window; we don't
   * want to mess up the widget's layer tree.
   */
  static nsresult PaintFrame(gfxContext* aRenderingContext, nsIFrame* aFrame,
                             const nsRegion& aDirtyRegion, nscolor aBackstop,
                             nsDisplayListBuilderMode aBuilderMode,
                             PaintFrameFlags aFlags = PaintFrameFlags(0));

  /**
   * Uses a binary search for find where the cursor falls in the line of text
   * It also keeps track of the part of the string that has already been
   * measured so it doesn't have to keep measuring the same text over and over.
   *
   * @param "aBaseWidth" contains the width in twips of the portion
   * of the text that has already been measured, and aBaseInx contains
   * the index of the text that has already been measured.
   *
   * @param aTextWidth returns (in twips) the length of the text that falls
   * before the cursor aIndex contains the index of the text where the cursor
   * falls.
   */
  static bool
  BinarySearchForPosition(DrawTarget* aDrawTarget,
                          nsFontMetrics& aFontMetrics,
                          const char16_t* aText,
                          int32_t    aBaseWidth,
                          int32_t    aBaseInx,
                          int32_t    aStartInx,
                          int32_t    aEndInx,
                          int32_t    aCursorPos,
                          int32_t&   aIndex,
                          int32_t&   aTextWidth);

  class BoxCallback {
  public:
    BoxCallback() : mIncludeCaptionBoxForTable(true) {}
    virtual void AddBox(nsIFrame* aFrame) = 0;
    bool mIncludeCaptionBoxForTable;
  };
  /**
   * Collect all CSS boxes associated with aFrame and its
   * continuations, "drilling down" through table wrapper frames and
   * some anonymous blocks since they're not real CSS boxes.
   * If aFrame is null, no boxes are returned.
   * SVG frames return a single box, themselves.
   */
  static void GetAllInFlowBoxes(nsIFrame* aFrame, BoxCallback* aCallback);

  /**
   * Like GetAllInFlowBoxes, but doesn't include continuations.
   */
  static void AddBoxesForFrame(nsIFrame* aFrame, BoxCallback* aCallback);

  /**
   * Find the first frame descendant of aFrame (including aFrame) which is
   * not an anonymous frame that getBoxQuads/getClientRects should ignore.
   */
  static nsIFrame* GetFirstNonAnonymousFrame(nsIFrame* aFrame);

  class RectCallback {
  public:
    virtual void AddRect(const nsRect& aRect) = 0;
  };

  struct RectAccumulator : public RectCallback {
    nsRect mResultRect;
    nsRect mFirstRect;
    bool mSeenFirstRect;

    RectAccumulator();

    virtual void AddRect(const nsRect& aRect) override;
  };

  struct RectListBuilder : public RectCallback {
    DOMRectList* mRectList;

    explicit RectListBuilder(DOMRectList* aList);
    virtual void AddRect(const nsRect& aRect) override;
  };

  static nsIFrame* GetContainingBlockForClientRect(nsIFrame* aFrame);

  enum {
    RECTS_ACCOUNT_FOR_TRANSFORMS = 0x01,
    // Two bits for specifying which box type to use.
    // With neither bit set (default), use the border box.
    RECTS_USE_CONTENT_BOX = 0x02,
    RECTS_USE_PADDING_BOX = 0x04,
    RECTS_USE_MARGIN_BOX = 0x06, // both bits set
    RECTS_WHICH_BOX_MASK = 0x06 // bitmask for these two bits
  };
  /**
   * Collect all CSS boxes (content, padding, border, or margin) associated
   * with aFrame and its continuations, "drilling down" through table wrapper
   * frames and some anonymous blocks since they're not real CSS boxes.
   * The boxes are positioned relative to aRelativeTo (taking scrolling
   * into account) and passed to the callback in frame-tree order.
   * If aFrame is null, no boxes are returned.
   * For SVG frames, returns one rectangle, the bounding box.
   * If aFlags includes RECTS_ACCOUNT_FOR_TRANSFORMS, then when converting
   * the boxes into aRelativeTo coordinates, transforms (including CSS
   * and SVG transforms) are taken into account.
   * If aFlags includes one of RECTS_USE_CONTENT_BOX, RECTS_USE_PADDING_BOX,
   * or RECTS_USE_MARGIN_BOX, the corresponding type of box is used.
   * Otherwise (by default), the border box is used.
   */
  static void GetAllInFlowRects(nsIFrame* aFrame, nsIFrame* aRelativeTo,
                                RectCallback* aCallback, uint32_t aFlags = 0);

  static void GetAllInFlowRectsAndTexts(nsIFrame* aFrame, nsIFrame* aRelativeTo,
                                        RectCallback* aCallback,
                                        mozilla::dom::Sequence<nsString>* aTextList,
                                        uint32_t aFlags = 0);

  /**
   * Computes the union of all rects returned by GetAllInFlowRects. If
   * the union is empty, returns the first rect.
   * If aFlags includes RECTS_ACCOUNT_FOR_TRANSFORMS, then when converting
   * the boxes into aRelativeTo coordinates, transforms (including CSS
   * and SVG transforms) are taken into account.
   * If aFlags includes one of RECTS_USE_CONTENT_BOX, RECTS_USE_PADDING_BOX,
   * or RECTS_USE_MARGIN_BOX, the corresponding type of box is used.
   * Otherwise (by default), the border box is used.
   */
  static nsRect GetAllInFlowRectsUnion(nsIFrame* aFrame, nsIFrame* aRelativeTo,
                                       uint32_t aFlags = 0);

  enum {
    EXCLUDE_BLUR_SHADOWS = 0x01
  };
  /**
   * Takes a text-shadow array from the style properties of a given nsIFrame and
   * computes the union of those shadows along with the given initial rect.
   * If there are no shadows, the initial rect is returned.
   */
  static nsRect GetTextShadowRectsUnion(const nsRect& aTextAndDecorationsRect,
                                        nsIFrame* aFrame,
                                        uint32_t aFlags = 0);

  /**
   * Computes the destination rect that a given replaced element should render
   * into, based on its CSS 'object-fit' and 'object-position' properties.
   *
   * @param aConstraintRect The constraint rect that we have at our disposal,
   *                        which would e.g. be exactly filled by the image
   *                        if we had "object-fit: fill".
   * @param aIntrinsicSize The replaced content's intrinsic size, as reported
   *                       by nsIFrame::GetIntrinsicSize().
   * @param aIntrinsicRatio The replaced content's intrinsic ratio, as reported
   *                        by nsIFrame::GetIntrinsicRatio().
   * @param aStylePos The nsStylePosition struct that contains the 'object-fit'
   *                  and 'object-position' values that we should rely on.
   *                  (This should usually be the nsStylePosition for the
   *                  replaced element in question, but not always. For
   *                  example, a <video>'s poster-image has a dedicated
   *                  anonymous element & child-frame, but we should still use
   *                  the <video>'s 'object-fit' and 'object-position' values.)
   * @param aAnchorPoint [out] A point that should be pixel-aligned by functions
   *                           like nsLayoutUtils::DrawImage. See documentation
   *                           in nsCSSRendering.h for ComputeObjectAnchorPoint.
   * @return The nsRect into which we should render the replaced content (using
   *         the same coordinate space as the passed-in aConstraintRect).
   */
  static nsRect ComputeObjectDestRect(const nsRect& aConstraintRect,
                                      const IntrinsicSize& aIntrinsicSize,
                                      const nsSize& aIntrinsicRatio,
                                      const nsStylePosition* aStylePos,
                                      nsPoint* aAnchorPoint = nullptr);

  /**
   * Get the font metrics corresponding to the frame's style data.
   * @param aFrame the frame
   * @param aSizeInflation number to multiply font size by
   */
  static already_AddRefed<nsFontMetrics> GetFontMetricsForFrame(
    const nsIFrame* aFrame, float aSizeInflation);

  static already_AddRefed<nsFontMetrics>
    GetInflatedFontMetricsForFrame(const nsIFrame* aFrame)
  {
    return GetFontMetricsForFrame(aFrame, FontSizeInflationFor(aFrame));
  }

  /**
   * Get the font metrics corresponding to the given style data.
   * @param aStyleContext the style data
   * @param aSizeInflation number to multiply font size by
   */
  static already_AddRefed<nsFontMetrics> GetFontMetricsForStyleContext(
      nsStyleContext* aStyleContext, float aSizeInflation = 1.0f,
      uint8_t aVariantWidth = NS_FONT_VARIANT_WIDTH_NORMAL);

  /**
   * Get the font metrics of emphasis marks corresponding to the given
   * style data. The result is same as GetFontMetricsForStyleContext
   * except that the font size is scaled down to 50%.
   * @param aStyleContext the style data
   * @param aInflation number to multiple font size by
   */
  static already_AddRefed<nsFontMetrics> GetFontMetricsOfEmphasisMarks(
      nsStyleContext* aStyleContext, float aInflation)
  {
    return GetFontMetricsForStyleContext(aStyleContext, aInflation * 0.5f);
  }

  /**
   * Find the immediate child of aParent whose frame subtree contains
   * aDescendantFrame. Returns null if aDescendantFrame is not a descendant
   * of aParent.
   */
  static nsIFrame* FindChildContainingDescendant(nsIFrame* aParent, nsIFrame* aDescendantFrame);

  /**
   * Find the nearest ancestor that's a block
   */
  static nsBlockFrame* FindNearestBlockAncestor(nsIFrame* aFrame);

  /**
   * Find the nearest ancestor that's not for generated content. Will return
   * aFrame if aFrame is not for generated content.
   */
  static nsIFrame* GetNonGeneratedAncestor(nsIFrame* aFrame);

  /**
   * Cast aFrame to an nsBlockFrame* or return null if it's not
   * an nsBlockFrame.
   */
  static nsBlockFrame* GetAsBlock(nsIFrame* aFrame);

  /*
   * Whether the frame is an nsBlockFrame which is not a wrapper block.
   */
  static bool IsNonWrapperBlock(nsIFrame* aFrame);

  /**
   * If aFrame is an out of flow frame, return its placeholder, otherwise
   * return its parent.
   */
  static nsIFrame* GetParentOrPlaceholderFor(nsIFrame* aFrame);

  /**
   * If aFrame is an out of flow frame, return its placeholder, otherwise
   * return its (possibly cross-doc) parent.
   */
  static nsIFrame* GetParentOrPlaceholderForCrossDoc(nsIFrame* aFrame);

  /**
   * Get a frame's next-in-flow, or, if it doesn't have one, its
   * block-in-inline-split sibling.
   */
  static nsIFrame*
  GetNextContinuationOrIBSplitSibling(nsIFrame *aFrame);

  /**
   * Get the first frame in the continuation-plus-ib-split-sibling chain
   * containing aFrame.
   */
  static nsIFrame*
  FirstContinuationOrIBSplitSibling(const nsIFrame *aFrame);

  /**
   * Get the last frame in the continuation-plus-ib-split-sibling chain
   * containing aFrame.
   */
  static nsIFrame*
  LastContinuationOrIBSplitSibling(const nsIFrame *aFrame);

  /**
   * Is FirstContinuationOrIBSplitSibling(aFrame) going to return
   * aFrame?
   */
  static bool
  IsFirstContinuationOrIBSplitSibling(nsIFrame *aFrame);

  /**
   * Check whether aFrame is a part of the scrollbar or scrollcorner of
   * the root content.
   * @param aFrame the checking frame.
   * @return true if the frame is a part of the scrollbar or scrollcorner of
   *         the root content.
   */
  static bool IsViewportScrollbarFrame(nsIFrame* aFrame);

  /**
   * Get the contribution of aFrame to its containing block's intrinsic
   * size for the given physical axis.  This considers the child's intrinsic
   * width, its 'width', 'min-width', and 'max-width' properties (or 'height'
   * variations if that's what matches aAxis) and its padding, border and margin
   * in the corresponding dimension.
   * @param aPercentageBasis an optional percentage basis (in aFrame's WM).
   *   Pass NS_UNCONSTRAINEDSIZE if the basis is indefinite in either/both axes.
   *   If you pass Nothing() a percentage basis will be calculated from aFrame's
   *   ancestors' computed size in the relevant axis, if needed.
   * @param aMarginBoxMinSizeClamp make the result fit within this margin-box
   * size by reducing the *content size* (flooring at zero).  This is used for:
   * https://drafts.csswg.org/css-grid/#min-size-auto
   */
  enum class IntrinsicISizeType { MIN_ISIZE, PREF_ISIZE };
  static const auto MIN_ISIZE = IntrinsicISizeType::MIN_ISIZE;
  static const auto PREF_ISIZE = IntrinsicISizeType::PREF_ISIZE;
  enum {
    IGNORE_PADDING = 0x01,
    BAIL_IF_REFLOW_NEEDED = 0x02, // returns NS_INTRINSIC_WIDTH_UNKNOWN if so
    MIN_INTRINSIC_ISIZE = 0x04, // use min-width/height instead of width/height
    ADD_PERCENTS = 0x08, // apply AddPercents also for MIN_ISIZE
  };
  static nscoord
  IntrinsicForAxis(mozilla::PhysicalAxis aAxis,
                   gfxContext*           aRenderingContext,
                   nsIFrame*             aFrame,
                   IntrinsicISizeType    aType,
                   const mozilla::Maybe<mozilla::LogicalSize>& aPercentageBasis = mozilla::Nothing(),
                   uint32_t              aFlags = 0,
                   nscoord               aMarginBoxMinSizeClamp = NS_MAXSIZE);
  /**
   * Calls IntrinsicForAxis with aFrame's parent's inline physical axis.
   */
  static nscoord IntrinsicForContainer(gfxContext*         aRenderingContext,
                                       nsIFrame*           aFrame,
                                       IntrinsicISizeType  aType,
                                       uint32_t            aFlags = 0);

  /**
   * Get the definite size contribution of aFrame for the given physical axis.
   * This considers the child's 'min-width' property (or 'min-height' if the
   * given axis is vertical), and its padding, border, and margin in the
   * corresponding dimension.  If the 'min-' property is 'auto' (and 'overflow'
   * is 'visible') and the corresponding 'width'/'height' is definite it returns
   * the "specified size" for:
   * https://drafts.csswg.org/css-grid/#min-size-auto
   * Note that the "transferred size" is not handled here; use IntrinsicForAxis.
   * Note that any percentage in 'width'/'height' makes it count as indefinite.
   * If the 'min-' property is 'auto' and 'overflow' is not 'visible', then it
   * calculates the result as if the 'min-' computed value is zero.
   * Otherwise, return NS_UNCONSTRAINEDSIZE.
   *
   * @note this behavior is specific to Grid/Flexbox (currently) so aFrame
   * should be a grid/flex item.
   */
  static nscoord MinSizeContributionForAxis(mozilla::PhysicalAxis aAxis,
                                            gfxContext*           aRC,
                                            nsIFrame*             aFrame,
                                            IntrinsicISizeType    aType,
                                            uint32_t              aFlags = 0);

  /**
   * This function increases an initial intrinsic size, 'aCurrent', according
   * to the given 'aPercent', such that the size-increase makes up exactly
   * 'aPercent' percent of the returned value.  If 'aPercent' or 'aCurrent' are
   * less than or equal to zero the original 'aCurrent' value is returned.
   * If 'aPercent' is greater than or equal to 1.0 the value nscoord_MAX is
   * returned.
   */
  static nscoord AddPercents(nscoord aCurrent, float aPercent)
  {
    if (aPercent > 0.0f && aCurrent > 0) {
      return MOZ_UNLIKELY(aPercent >= 1.0f) ? nscoord_MAX
        : NSToCoordRound(float(aCurrent) / (1.0f - aPercent));
    }
    return aCurrent;
  }

  /*
   * Convert nsStyleCoord to nscoord when percentages depend on the
   * containing block size.
   * @param aPercentBasis The width or height of the containing block
   * (whichever the client wants to use for resolving percentages).
   */
  static nscoord ComputeCBDependentValue(nscoord aPercentBasis,
                                         const nsStyleCoord& aCoord);

  static nscoord ComputeBSizeDependentValue(
                   nscoord              aContainingBlockBSize,
                   const nsStyleCoord&  aCoord);

  static nscoord ComputeBSizeValue(nscoord aContainingBlockBSize,
                                    nscoord aContentEdgeToBoxSizingBoxEdge,
                                    const nsStyleCoord& aCoord)
  {
    MOZ_ASSERT(aContainingBlockBSize != nscoord_MAX || !aCoord.HasPercent(),
               "caller must deal with %% of unconstrained block-size");
    MOZ_ASSERT(aCoord.IsCoordPercentCalcUnit());

    nscoord result =
      nsRuleNode::ComputeCoordPercentCalc(aCoord, aContainingBlockBSize);
    // Clamp calc(), and the subtraction for box-sizing.
    return std::max(0, result - aContentEdgeToBoxSizingBoxEdge);
  }

  // XXX to be removed
  static bool IsAutoHeight(const nsStyleCoord &aCoord, nscoord aCBHeight)
  {
    return IsAutoBSize(aCoord, aCBHeight);
  }

  static bool IsAutoBSize(const nsStyleCoord &aCoord, nscoord aCBBSize)
  {
    nsStyleUnit unit = aCoord.GetUnit();
    return unit == eStyleUnit_Auto ||  // only for 'height'
           unit == eStyleUnit_None ||  // only for 'max-height'
           // The enumerated values were originally aimed at inline-size
           // (or width, as it was before logicalization). For now, let them
           // return true here, so that we don't call ComputeBSizeValue with
           // value types that it doesn't understand. (See bug 1113216.)
           //
           // FIXME (bug 567039, bug 527285)
           // This isn't correct for the 'fill' value or for the 'min-*' or
           // 'max-*' properties, which need to be handled differently by
           // the callers of IsAutoBSize().
           unit == eStyleUnit_Enumerated ||
           (aCBBSize == nscoord_MAX && aCoord.HasPercent());
  }

  static bool IsPaddingZero(const nsStyleCoord &aCoord)
  {
    return (aCoord.GetUnit() == eStyleUnit_Coord &&
            aCoord.GetCoordValue() == 0) ||
           (aCoord.GetUnit() == eStyleUnit_Percent &&
            aCoord.GetPercentValue() == 0.0f) ||
           (aCoord.IsCalcUnit() &&
            // clamp negative calc() to 0
            nsRuleNode::ComputeCoordPercentCalc(aCoord, nscoord_MAX) <= 0 &&
            nsRuleNode::ComputeCoordPercentCalc(aCoord, 0) <= 0);
  }

  static bool IsMarginZero(const nsStyleCoord &aCoord)
  {
    return (aCoord.GetUnit() == eStyleUnit_Coord &&
            aCoord.GetCoordValue() == 0) ||
           (aCoord.GetUnit() == eStyleUnit_Percent &&
            aCoord.GetPercentValue() == 0.0f) ||
           (aCoord.IsCalcUnit() &&
            nsRuleNode::ComputeCoordPercentCalc(aCoord, nscoord_MAX) == 0 &&
            nsRuleNode::ComputeCoordPercentCalc(aCoord, 0) == 0);
  }

  static void MarkDescendantsDirty(nsIFrame *aSubtreeRoot);

  static void MarkIntrinsicISizesDirtyIfDependentOnBSize(nsIFrame* aFrame);

  /*
   * Calculate the used values for 'width' and 'height' when width
   * and height are 'auto'. The tentWidth and tentHeight arguments should be
   * the result of applying the rules for computing intrinsic sizes and ratios.
   * as specified by CSS 2.1 sections 10.3.2 and 10.6.2
   */
  static nsSize ComputeAutoSizeWithIntrinsicDimensions(nscoord minWidth, nscoord minHeight,
                                                       nscoord maxWidth, nscoord maxHeight,
                                                       nscoord tentWidth, nscoord tentHeight);

  // Implement nsIFrame::GetPrefISize in terms of nsIFrame::AddInlinePrefISize
  static nscoord PrefISizeFromInline(nsIFrame* aFrame,
                                     gfxContext* aRenderingContext);

  // Implement nsIFrame::GetMinISize in terms of nsIFrame::AddInlineMinISize
  static nscoord MinISizeFromInline(nsIFrame* aFrame,
                                    gfxContext* aRenderingContext);

  // Get a suitable foreground color for painting aColor for aFrame.
  static nscolor DarkenColorIfNeeded(nsIFrame* aFrame, nscolor aColor);

  // Get a suitable foreground color for painting aField for aFrame.
  // Type of aFrame is made a template parameter because nsIFrame is not
  // a complete type in the header. Type-safety is not harmed given that
  // DarkenColorIfNeeded requires an nsIFrame pointer.
  template<typename Frame, typename T, typename S>
  static nscolor GetColor(Frame* aFrame, T S::* aField) {
    nscolor color = aFrame->GetVisitedDependentColor(aField);
    return DarkenColorIfNeeded(aFrame, color);
  }

  // Get a baseline y position in app units that is snapped to device pixels.
  static gfxFloat GetSnappedBaselineY(nsIFrame* aFrame, gfxContext* aContext,
                                      nscoord aY, nscoord aAscent);
  // Ditto for an x position (for vertical text). Note that for vertical-rl
  // writing mode, the ascent value should be negated by the caller.
  static gfxFloat GetSnappedBaselineX(nsIFrame* aFrame, gfxContext* aContext,
                                      nscoord aX, nscoord aAscent);

  static nscoord AppUnitWidthOfString(char16_t aC,
                                      nsFontMetrics& aFontMetrics,
                                      DrawTarget* aDrawTarget) {
    return AppUnitWidthOfString(&aC, 1, aFontMetrics, aDrawTarget);
  }
  static nscoord AppUnitWidthOfString(const nsString& aString,
                                      nsFontMetrics& aFontMetrics,
                                      DrawTarget* aDrawTarget) {
    return nsLayoutUtils::AppUnitWidthOfString(aString.get(), aString.Length(),
                                               aFontMetrics, aDrawTarget);
  }
  static nscoord AppUnitWidthOfString(const char16_t *aString,
                                      uint32_t aLength,
                                      nsFontMetrics& aFontMetrics,
                                      DrawTarget* aDrawTarget);
  static nscoord AppUnitWidthOfStringBidi(const nsString& aString,
                                          const nsIFrame* aFrame,
                                          nsFontMetrics& aFontMetrics,
                                          gfxContext& aContext) {
    return nsLayoutUtils::AppUnitWidthOfStringBidi(aString.get(),
                                                   aString.Length(), aFrame,
                                                   aFontMetrics, aContext);
  }
  static nscoord AppUnitWidthOfStringBidi(const char16_t* aString,
                                          uint32_t aLength,
                                          const nsIFrame* aFrame,
                                          nsFontMetrics& aFontMetrics,
                                          gfxContext& aContext);

  static bool StringWidthIsGreaterThan(const nsString& aString,
                                       nsFontMetrics& aFontMetrics,
                                       DrawTarget* aDrawTarget,
                                       nscoord aWidth);

  static nsBoundingMetrics AppUnitBoundsOfString(const char16_t* aString,
                                                 uint32_t aLength,
                                                 nsFontMetrics& aFontMetrics,
                                                 DrawTarget* aDrawTarget);

  static void DrawString(const nsIFrame*     aFrame,
                         nsFontMetrics&      aFontMetrics,
                         gfxContext*         aContext,
                         const char16_t*     aString,
                         int32_t             aLength,
                         nsPoint             aPoint,
                         nsStyleContext*     aStyleContext = nullptr,
                         DrawStringFlags     aFlags = DrawStringFlags::eDefault);

  static nsPoint GetBackgroundFirstTilePos(const nsPoint& aDest,
                                           const nsPoint& aFill,
                                           const nsSize& aRepeatSize);

  /**
   * Supports only LTR or RTL. Bidi (mixed direction) is not supported.
   */
  static void DrawUniDirString(const char16_t* aString,
                               uint32_t aLength,
                               nsPoint aPoint,
                               nsFontMetrics& aFontMetrics,
                               gfxContext& aContext);

  /**
   * Helper function for drawing text-shadow. The callback's job
   * is to draw whatever needs to be blurred onto the given context.
   */
  typedef void (* TextShadowCallback)(gfxContext* aCtx,
                                      nsPoint aShadowOffset,
                                      const nscolor& aShadowColor,
                                      void* aData);

  static void PaintTextShadow(const nsIFrame*     aFrame,
                              gfxContext*         aContext,
                              const nsRect&       aTextRect,
                              const nsRect&       aDirtyRect,
                              const nscolor&      aForegroundColor,
                              TextShadowCallback  aCallback,
                              void*               aCallbackData);

  /**
   * Gets the baseline to vertically center text from a font within a
   * line of specified height.
   * aIsInverted: true if the text is inverted relative to the block
   * direction, so that the block-dir "ascent" corresponds to font
   * descent. (Applies to sideways text in vertical-lr mode.)
   *
   * Returns the baseline position relative to the top of the line.
   */
  static nscoord GetCenteredFontBaseline(nsFontMetrics* aFontMetrics,
                                         nscoord        aLineHeight,
                                         bool           aIsInverted);

  /**
   * Derive a baseline of |aFrame| (measured from its top border edge)
   * from its first in-flow line box (not descending into anything with
   * 'overflow' not 'visible', potentially including aFrame itself).
   *
   * Returns true if a baseline was found (and fills in aResult).
   * Otherwise returns false.
   */
  static bool GetFirstLineBaseline(mozilla::WritingMode aWritingMode,
                                   const nsIFrame* aFrame, nscoord* aResult);

  /**
   * Just like GetFirstLineBaseline, except also returns the top and
   * bottom of the line with the baseline.
   *
   * Returns true if a line was found (and fills in aResult).
   * Otherwise returns false.
   */
  struct LinePosition {
    nscoord mBStart, mBaseline, mBEnd;

    LinePosition operator+(nscoord aOffset) const {
      LinePosition result;
      result.mBStart = mBStart + aOffset;
      result.mBaseline = mBaseline + aOffset;
      result.mBEnd = mBEnd + aOffset;
      return result;
    }
  };
  static bool GetFirstLinePosition(mozilla::WritingMode aWritingMode,
                                   const nsIFrame* aFrame,
                                   LinePosition* aResult);


  /**
   * Derive a baseline of |aFrame| (measured from its top border edge)
   * from its last in-flow line box (not descending into anything with
   * 'overflow' not 'visible', potentially including aFrame itself).
   *
   * Returns true if a baseline was found (and fills in aResult).
   * Otherwise returns false.
   */
  static bool GetLastLineBaseline(mozilla::WritingMode aWritingMode,
                                  const nsIFrame* aFrame, nscoord* aResult);

  /**
   * Returns a block-dir coordinate relative to this frame's origin that
   * represents the logical block-end of the frame or its visible content,
   * whichever is further from the origin.
   * Relative positioning is ignored and margins and glyph bounds are not
   * considered.
   * This value will be >= mRect.BSize() and <= overflowRect.BEnd() unless
   * relative positioning is applied.
   */
  static nscoord CalculateContentBEnd(mozilla::WritingMode aWritingMode,
                                      nsIFrame* aFrame);

  /**
   * Gets the closest frame (the frame passed in or one of its parents) that
   * qualifies as a "layer"; used in DOM0 methods that depends upon that
   * definition. This is the nearest frame that is either positioned or scrolled
   * (the child of a scroll frame).
   */
  static nsIFrame* GetClosestLayer(nsIFrame* aFrame);

  /**
   * Gets the graphics sampling filter for the frame
   */
  static SamplingFilter GetSamplingFilterForFrame(nsIFrame* aFrame);

  static inline void InitDashPattern(StrokeOptions& aStrokeOptions,
                                     uint8_t aBorderStyle) {
    if (aBorderStyle == NS_STYLE_BORDER_STYLE_DOTTED) {
      static Float dot[] = { 1.f, 1.f };
      aStrokeOptions.mDashLength = MOZ_ARRAY_LENGTH(dot);
      aStrokeOptions.mDashPattern = dot;
    } else if (aBorderStyle == NS_STYLE_BORDER_STYLE_DASHED) {
      static Float dash[] = { 5.f, 5.f };
      aStrokeOptions.mDashLength = MOZ_ARRAY_LENGTH(dash);
      aStrokeOptions.mDashPattern = dash;
    } else {
      aStrokeOptions.mDashLength = 0;
      aStrokeOptions.mDashPattern = nullptr;
    }
  }

  /**
   * Convert an nsRect to a gfxRect.
   */
  static gfxRect RectToGfxRect(const nsRect& aRect,
                               int32_t aAppUnitsPerDevPixel);

  static gfxPoint PointToGfxPoint(const nsPoint& aPoint,
                                  int32_t aAppUnitsPerPixel) {
    return gfxPoint(gfxFloat(aPoint.x) / aAppUnitsPerPixel,
                    gfxFloat(aPoint.y) / aAppUnitsPerPixel);
  }

  /* N.B. The only difference between variants of the Draw*Image
   * functions below is the type of the aImage argument.
   */

  /**
   * Draw a background image.  The image's dimensions are as specified in aDest;
   * the image itself is not consulted to determine a size.
   * See https://wiki.mozilla.org/Gecko:Image_Snapping_and_Rendering
   *   @param aContext          The context to draw to, already set up with an
   *                            appropriate scale and transform for drawing in
   *                            app units.
   *   @param aForFrame         The nsIFrame that we're drawing this image for.
   *   @param aImage            The image.
   *   @param aImageSize        The unscaled size of the image being drawn.
   *                            (This might be the image's size if no scaling
   *                            occurs, or it might be the image's size if
   *                            the image is a vector image being rendered at
   *                            that size.)
   *   @param aDest             The position and scaled area where one copy of
   *                            the image should be drawn. This area represents
   *                            the image itself in its correct position as defined
   *                            with the background-position css property.
   *   @param aFill             The area to be filled with copies of the image.
   *   @param aRepeatSize       The distance between the positions of two subsequent
   *                            repeats of the image. Sizes larger than aDest.Size()
   *                            create gaps between the images.
   *   @param aAnchor           A point in aFill which we will ensure is
   *                            pixel-aligned in the output.
   *   @param aDirty            Pixels outside this area may be skipped.
   *   @param aImageFlags       Image flags of the imgIContainer::FLAG_* variety.
   *   @param aExtendMode       How to extend the image over the dest rect.
   */
  static DrawResult DrawBackgroundImage(gfxContext&         aContext,
                                        nsIFrame*           aForFrame,
                                        nsPresContext*      aPresContext,
                                        imgIContainer*      aImage,
                                        const CSSIntSize&   aImageSize,
                                        SamplingFilter      aSamplingFilter,
                                        const nsRect&       aDest,
                                        const nsRect&       aFill,
                                        const nsSize&       aRepeatSize,
                                        const nsPoint&      aAnchor,
                                        const nsRect&       aDirty,
                                        uint32_t            aImageFlags,
                                        ExtendMode          aExtendMode,
                                        float               aOpacity);

  /**
   * Draw an image.
   * See https://wiki.mozilla.org/Gecko:Image_Snapping_and_Rendering
   *   @param aRenderingContext Where to draw the image, set up with an
   *                            appropriate scale and transform for drawing in
   *                            app units.
   *   @param aStyleContext     The style context of the nsIFrame (or
   *                            pseudo-element) for which this image is being
   *                            drawn.
   *   @param aImage            The image.
   *   @param aDest             Where one copy of the image should mapped to.
   *   @param aFill             The area to be filled with copies of the
   *                            image.
   *   @param aAnchor           A point in aFill which we will ensure is
   *                            pixel-aligned in the output.
   *   @param aDirty            Pixels outside this area may be skipped.
   *   @param aImageFlags       Image flags of the imgIContainer::FLAG_* variety
   */
  static DrawResult DrawImage(gfxContext&         aContext,
                              nsStyleContext*     aStyleContext,
                              nsPresContext*      aPresContext,
                              imgIContainer*      aImage,
                              const SamplingFilter aSamplingFilter,
                              const nsRect&       aDest,
                              const nsRect&       aFill,
                              const nsPoint&      aAnchor,
                              const nsRect&       aDirty,
                              uint32_t            aImageFlags,
                              float               aOpacity = 1.0);

  /**
   * Draw a whole image without scaling or tiling.
   *
   *   @param aRenderingContext Where to draw the image, set up with an
   *                            appropriate scale and transform for drawing in
   *                            app units.
   *   @param aImage            The image.
   *   @param aDest             The top-left where the image should be drawn.
   *   @param aDirty            If non-null, then pixels outside this area may
   *                            be skipped.
   *   @param aImageFlags       Image flags of the imgIContainer::FLAG_* variety
   *   @param aSourceArea       If non-null, this area is extracted from
   *                            the image and drawn at aDest. It's
   *                            in appunits. For best results it should
   *                            be aligned with image pixels.
   */
  static DrawResult DrawSingleUnscaledImage(gfxContext&          aContext,
                                            nsPresContext*       aPresContext,
                                            imgIContainer*       aImage,
                                            const SamplingFilter aSamplingFilter,
                                            const nsPoint&       aDest,
                                            const nsRect*        aDirty,
                                            uint32_t             aImageFlags,
                                            const nsRect*        aSourceArea = nullptr);

  /**
   * Draw a whole image without tiling.
   *
   *   @param aRenderingContext Where to draw the image, set up with an
   *                            appropriate scale and transform for drawing in
   *                            app units.
   *   @param aImage            The image.
   *   @param aDest             The area that the image should fill.
   *   @param aDirty            Pixels outside this area may be skipped.
   *   @param aSVGContext       Optionally provides an SVGImageContext.
   *                            Callers should pass an SVGImageContext with at
   *                            least the viewport size set if aImage may be of
   *                            type imgIContainer::TYPE_VECTOR, or pass
   *                            Nothing() if it is of type
   *                            imgIContainer::TYPE_RASTER (to save cycles
   *                            constructing an SVGImageContext, since this
   *                            argument will be ignored for raster images).
   *   @param aImageFlags       Image flags of the imgIContainer::FLAG_*
   *                            variety.
   *   @param aAnchor           If non-null, a point which we will ensure
   *                            is pixel-aligned in the output.
   *   @param aSourceArea       If non-null, this area is extracted from
   *                            the image and drawn in aDest. It's
   *                            in appunits. For best results it should
   *                            be aligned with image pixels.
   */
  static DrawResult DrawSingleImage(gfxContext&         aContext,
                                    nsPresContext*      aPresContext,
                                    imgIContainer*      aImage,
                                    const SamplingFilter aSamplingFilter,
                                    const nsRect&       aDest,
                                    const nsRect&       aDirty,
                                    const mozilla::Maybe<SVGImageContext>& aSVGContext,
                                    uint32_t            aImageFlags,
                                    const nsPoint*      aAnchorPoint = nullptr,
                                    const nsRect*       aSourceArea = nullptr);

  /**
   * Given an imgIContainer, this method attempts to obtain an intrinsic
   * px-valued height & width for it.  If the imgIContainer has a non-pixel
   * value for either height or width, this method tries to generate a pixel
   * value for that dimension using the intrinsic ratio (if available).  The
   * intrinsic ratio will be assigned to aIntrinsicRatio; if there's no
   * intrinsic ratio then (0, 0) will be assigned.
   *
   * This method will always set aGotWidth and aGotHeight to indicate whether
   * we were able to successfully obtain (or compute) a value for each
   * dimension.
   *
   * NOTE: This method is similar to ComputeSizeWithIntrinsicDimensions.  The
   * difference is that this one is simpler and is suited to places where we
   * have less information about the frame tree.
   */
  static void ComputeSizeForDrawing(imgIContainer* aImage,
                                    CSSIntSize&    aImageSize,
                                    nsSize&        aIntrinsicRatio,
                                    bool&          aGotWidth,
                                    bool&          aGotHeight);

  /**
   * Given an imgIContainer, this method attempts to obtain an intrinsic
   * px-valued height & width for it. If the imgIContainer has a non-pixel
   * value for either height or width, this method tries to generate a pixel
   * value for that dimension using the intrinsic ratio (if available). If,
   * after trying all these methods, no value is available for one or both
   * dimensions, the corresponding dimension of aFallbackSize is used instead.
   */
  static CSSIntSize
  ComputeSizeForDrawingWithFallback(imgIContainer* aImage,
                                    const nsSize&  aFallbackSize);

  /**
   * Given a source area of an image (in appunits) and a destination area
   * that we want to map that source area too, computes the area that
   * would be covered by the whole image. This is useful for passing to
   * the aDest parameter of DrawImage, when we want to draw a subimage
   * of an overall image.
   */
  static nsRect GetWholeImageDestination(const nsSize& aWholeImageSize,
                                         const nsRect& aImageSourceArea,
                                         const nsRect& aDestArea);

  /**
   * Given an image container and an orientation, returns an image container
   * that contains the same image, reoriented appropriately. May return the
   * original image container if no changes are needed.
   *
   * @param aContainer   The image container to apply the orientation to.
   * @param aOrientation The desired orientation.
   */
  static already_AddRefed<imgIContainer>
  OrientImage(imgIContainer* aContainer,
              const nsStyleImageOrientation& aOrientation);

  /**
   * Determine if any corner radius is of nonzero size
   *   @param aCorners the |nsStyleCorners| object to check
   *   @return true unless all the coordinates are 0%, 0 or null.
   *
   * A corner radius with one dimension zero and one nonzero is
   * treated as a nonzero-radius corner, even though it will end up
   * being rendered like a zero-radius corner.  This is because such
   * corners are not expected to appear outside of test cases, and it's
   * simpler to implement the test this way.
   */
  static bool HasNonZeroCorner(const nsStyleCorners& aCorners);

  /**
   * Determine if there is any corner radius on corners adjacent to the
   * given side.
   */
  static bool HasNonZeroCornerOnSide(const nsStyleCorners& aCorners,
                                       mozilla::Side aSide);

  /**
   * Determine if a widget is likely to require transparency or translucency.
   *   @param aBackgroundFrame The frame that the background is set on. For
   *                           <window>s, this will be the canvas frame.
   *   @param aCSSRootFrame    The frame that holds CSS properties affecting
   *                           the widget's transparency. For menupopups,
   *                           aBackgroundFrame and aCSSRootFrame will be the
   *                           same.
   *   @return a value suitable for passing to SetWindowTranslucency.
   */
  static nsTransparencyMode GetFrameTransparency(nsIFrame* aBackgroundFrame,
                                                 nsIFrame* aCSSRootFrame);

  /**
   * A frame is a popup if it has its own floating window. Menus, panels
   * and combobox dropdowns are popups.
   */
  static bool IsPopup(nsIFrame* aFrame);

  /**
   * Find the nearest "display root". This is the nearest enclosing
   * popup frame or the root prescontext's root frame.
   */
  static nsIFrame* GetDisplayRootFrame(nsIFrame* aFrame);

  /**
   * Get the reference frame that would be used when constructing a
   * display item for this frame.  Rather than using their own frame
   * as a reference frame.)
   *
   * This duplicates some of the logic of GetDisplayRootFrame above and
   * of nsDisplayListBuilder::FindReferenceFrameFor.
   *
   * If you have an nsDisplayListBuilder, you should get the reference
   * frame from it instead of calling this.
   */
  static nsIFrame* GetReferenceFrame(nsIFrame* aFrame);

  /**
   * Get textrun construction flags determined by a given style; in particular
   * some combination of:
   * -- TEXT_DISABLE_OPTIONAL_LIGATURES if letter-spacing is in use
   * -- TEXT_OPTIMIZE_SPEED if the text-rendering CSS property and font size
   * and prefs indicate we should be optimizing for speed over quality
   */
  static mozilla::gfx::ShapedTextFlags
  GetTextRunFlagsForStyle(nsStyleContext* aStyleContext,
                          const nsStyleFont* aStyleFont,
                          const nsStyleText* aStyleText,
                          nscoord aLetterSpacing);

  /**
   * Get orientation flags for textrun construction.
   */
  static mozilla::gfx::ShapedTextFlags
  GetTextRunOrientFlagsForStyle(nsStyleContext* aStyleContext);

  /**
   * Takes two rectangles whose origins must be the same, and computes
   * the difference between their union and their intersection as two
   * rectangles. (This difference is a superset of the difference
   * between the two rectangles.)
   */
  static void GetRectDifferenceStrips(const nsRect& aR1, const nsRect& aR2,
                                      nsRect* aHStrip, nsRect* aVStrip);

  /**
   * Get a device context that can be used to get up-to-date device
   * dimensions for the given window. For some reason, this is more
   * complicated than it ought to be in multi-monitor situations.
   */
  static nsDeviceContext*
  GetDeviceContextForScreenInfo(nsPIDOMWindowOuter* aWindow);

  /**
   * Some frames with 'position: fixed' (nsStylePosition::mDisplay ==
   * NS_STYLE_POSITION_FIXED) are not really fixed positioned, since
   * they're inside an element with -moz-transform.  This function says
   * whether such an element is a real fixed-pos element.
   */
  static bool IsReallyFixedPos(nsIFrame* aFrame);

  /**
   * Obtain a SourceSurface from the given DOM element, if possible.
   * This obtains the most natural surface from the element; that
   * is, the one that can be obtained with the fewest conversions.
   *
   * The flags below can modify the behaviour of this function.  The
   * result is returned as a SurfaceFromElementResult struct, also
   * defined below.
   *
   * Currently, this will do:
   *  - HTML Canvas elements: will return the underlying canvas surface
   *  - HTML Video elements: will return the current video frame
   *  - Image elements: will return the image
   *
   * The above results are modified by the below flags (copying,
   * forcing image surface, etc.).
   */

  enum {
    /* When creating a new surface, create an image surface */
    SFE_WANT_IMAGE_SURFACE = 1 << 0,
    /* Whether to extract the first frame (as opposed to the
       current frame) in the case that the element is an image. */
    SFE_WANT_FIRST_FRAME_IF_IMAGE = 1 << 1,
    /* Whether we should skip colorspace/gamma conversion */
    SFE_NO_COLORSPACE_CONVERSION = 1 << 2,
    /* Specifies that the caller wants either OPAQUE or NON_PREMULT mAlphaType,
       if this is can be done efficiently. */
    SFE_PREFER_NO_PREMULTIPLY_ALPHA = 1 << 3,
    /* Whether we should skip getting a surface for vector images and
       return a DirectDrawInfo containing an imgIContainer instead. */
    SFE_NO_RASTERIZING_VECTORS = 1 << 4,
    /* If image type is vector, the return surface size will same as
       element size, not image's intrinsic size. */
    SFE_USE_ELEMENT_SIZE_IF_VECTOR = 1 << 5
  };

  struct DirectDrawInfo {
    /* imgIContainer to directly draw to a context */
    nsCOMPtr<imgIContainer> mImgContainer;
    /* which frame to draw */
    uint32_t mWhichFrame;
    /* imgIContainer flags to use when drawing */
    uint32_t mDrawingFlags;
  };

  struct SurfaceFromElementResult {
    friend class mozilla::dom::CanvasRenderingContext2D;
    friend class nsLayoutUtils;

    /* If SFEResult contains a valid surface, it either mLayersImage or mSourceSurface
     * will be non-null, and GetSourceSurface() will not be null.
     *
     * For valid surfaces, mSourceSurface may be null if mLayersImage is non-null, but
     * GetSourceSurface() will create mSourceSurface from mLayersImage when called.
     */

    /* Video elements (at least) often are already decoded as layers::Images. */
    RefPtr<mozilla::layers::Image> mLayersImage;

protected:
    /* GetSourceSurface() fills this and returns its non-null value if this SFEResult
     * was successful. */
    RefPtr<mozilla::gfx::SourceSurface> mSourceSurface;

public:
    /* Contains info for drawing when there is no mSourceSurface. */
    DirectDrawInfo mDrawInfo;

    /* The size of the surface */
    mozilla::gfx::IntSize mSize;
    /* The principal associated with the element whose surface was returned.
       If there is a surface, this will never be null. */
    nsCOMPtr<nsIPrincipal> mPrincipal;
    /* The image request, if the element is an nsIImageLoadingContent */
    nsCOMPtr<imgIRequest> mImageRequest;
    /* Whether the element was "write only", that is, the bits should not be exposed to content */
    bool mIsWriteOnly;
    /* Whether the element was still loading.  Some consumers need to handle
       this case specially. */
    bool mIsStillLoading;
    /* Whether the element has a valid size. */
    bool mHasSize;
    /* Whether the element used CORS when loading. */
    bool mCORSUsed;

    gfxAlphaType mAlphaType;

    // Methods:

    SurfaceFromElementResult();

    // Gets mSourceSurface, or makes a SourceSurface from mLayersImage.
    const RefPtr<mozilla::gfx::SourceSurface>& GetSourceSurface();
  };

  // This function can be called on any thread.
  static SurfaceFromElementResult
  SurfaceFromOffscreenCanvas(mozilla::dom::OffscreenCanvas *aOffscreenCanvas,
                             uint32_t aSurfaceFlags,
                             RefPtr<DrawTarget>& aTarget);
  static SurfaceFromElementResult
  SurfaceFromOffscreenCanvas(mozilla::dom::OffscreenCanvas *aOffscreenCanvas,
                             uint32_t aSurfaceFlags = 0) {
    RefPtr<DrawTarget> target = nullptr;
    return SurfaceFromOffscreenCanvas(aOffscreenCanvas, aSurfaceFlags, target);
  }

  static SurfaceFromElementResult SurfaceFromElement(mozilla::dom::Element *aElement,
                                                     uint32_t aSurfaceFlags,
                                                     RefPtr<DrawTarget>& aTarget);
  static SurfaceFromElementResult SurfaceFromElement(mozilla::dom::Element *aElement,
                                                     uint32_t aSurfaceFlags = 0) {
    RefPtr<DrawTarget> target = nullptr;
    return SurfaceFromElement(aElement, aSurfaceFlags, target);
  }

  static SurfaceFromElementResult SurfaceFromElement(nsIImageLoadingContent *aElement,
                                                     uint32_t aSurfaceFlags,
                                                     RefPtr<DrawTarget>& aTarget);
  // Need an HTMLImageElement overload, because otherwise the
  // nsIImageLoadingContent and mozilla::dom::Element overloads are ambiguous
  // for HTMLImageElement.
  static SurfaceFromElementResult SurfaceFromElement(mozilla::dom::HTMLImageElement *aElement,
                                                     uint32_t aSurfaceFlags,
                                                     RefPtr<DrawTarget>& aTarget);
  static SurfaceFromElementResult SurfaceFromElement(mozilla::dom::HTMLCanvasElement *aElement,
                                                     uint32_t aSurfaceFlags,
                                                     RefPtr<DrawTarget>& aTarget);
  static SurfaceFromElementResult SurfaceFromElement(mozilla::dom::HTMLVideoElement *aElement,
                                                     uint32_t aSurfaceFlags,
                                                     RefPtr<DrawTarget>& aTarget);

  /**
   * When the document is editable by contenteditable attribute of its root
   * content or body content.
   *
   * Be aware, this returns nullptr if it's in designMode.
   *
   * For example:
   *
   *  <html contenteditable="true"><body></body></html>
   *    returns the <html>.
   *
   *  <html><body contenteditable="true"></body></html>
   *  <body contenteditable="true"></body>
   *    With these cases, this returns the <body>.
   *    NOTE: The latter case isn't created normally, however, it can be
   *          created by script with XHTML.
   *
   *  <body><p contenteditable="true"></p></body>
   *    returns nullptr because <body> isn't editable.
   */
  static nsIContent*
    GetEditableRootContentByContentEditable(nsIDocument* aDocument);

  /**
   * Returns true if the passed in prescontext needs the dark grey background
   * that goes behind the page of a print preview presentation.
   */
  static bool NeedsPrintPreviewBackground(nsPresContext* aPresContext);

  /**
   * Adds all font faces used in the frame tree starting from aFrame
   * to the list aFontFaceList.
   */
  static nsresult GetFontFacesForFrames(nsIFrame* aFrame,
                                        nsFontFaceList* aFontFaceList);

  /**
   * Adds all font faces used within the specified range of text in aFrame,
   * and optionally its continuations, to the list in aFontFaceList.
   * Pass 0 and INT32_MAX for aStartOffset and aEndOffset to specify the
   * entire text is to be considered.
   */
  static nsresult GetFontFacesForText(nsIFrame* aFrame,
                                      int32_t aStartOffset,
                                      int32_t aEndOffset,
                                      bool aFollowContinuations,
                                      nsFontFaceList* aFontFaceList);

  /**
   * Walks the frame tree starting at aFrame looking for textRuns.
   * If |clear| is true, just clears the TEXT_RUN_MEMORY_ACCOUNTED flag
   * on each textRun found (and |aMallocSizeOf| is not used).
   * If |clear| is false, adds the storage used for each textRun to the
   * total, and sets the TEXT_RUN_MEMORY_ACCOUNTED flag to avoid double-
   * accounting. (Runs with this flag already set will be skipped.)
   * Expected usage pattern is therefore to call twice:
   *    (void)SizeOfTextRunsForFrames(rootFrame, nullptr, true);
   *    total = SizeOfTextRunsForFrames(rootFrame, mallocSizeOf, false);
   */
  static size_t SizeOfTextRunsForFrames(nsIFrame* aFrame,
                                        mozilla::MallocSizeOf aMallocSizeOf,
                                        bool clear);

  /**
   * Returns true if the frame has any current CSS transitions.
   * A current transition is any transition that has not yet finished playing
   * including paused transitions.
   */
  static bool HasCurrentTransitions(const nsIFrame* aFrame);

  /**
   * Returns true if |aFrame| has an animation of |aProperty| regardless of
   * whether the property is overridden by !important rule.
   */
  static bool HasAnimationOfProperty(const nsIFrame* aFrame,
                                     nsCSSPropertyID aProperty);

  /**
   * Returns true if |aEffectSet| has an animation of |aProperty| regardless of
   * whether the property is overridden by !important rule.
   */
  static bool HasAnimationOfProperty(mozilla::EffectSet* aEffectSet,
                                     nsCSSPropertyID aProperty);

  /**
   * Returns true if |aFrame| has an animation of |aProperty| which is
   * not overridden by !important rules.
   */
  static bool HasEffectiveAnimation(const nsIFrame* aFrame,
                                    nsCSSPropertyID aProperty);

  /**
   * Checks if off-main-thread animations are enabled.
   */
  static bool AreAsyncAnimationsEnabled();

  /**
   * Checks if we should warn about animations that can't be async
   */
  static bool IsAnimationLoggingEnabled();

  /**
   * Find a suitable scale for a element (aFrame's content) over the course of any
   * animations and transitions of the CSS transform property on the
   * element that run on the compositor thread.
   * It will check the maximum and minimum scale during the animations and
   * transitions and return a suitable value for performance and quality.
   * Will return scale(1,1) if there are no such animations.
   * Always returns a positive value.
   * @param aVisibleSize is the size of the area we want to paint
   * @param aDisplaySize is the size of the display area of the pres context
   */
  static gfxSize ComputeSuitableScaleForAnimation(const nsIFrame* aFrame,
                                                  const nsSize& aVisibleSize,
                                                  const nsSize& aDisplaySize);

  /**
   * Checks whether we want to use the GPU to scale images when
   * possible.
   */
  static bool GPUImageScalingEnabled();

  /**
   * Checks whether we want to layerize animated images whenever possible.
   */
  static bool AnimatedImageLayersEnabled();

  /**
   * Checks if we should enable parsing for CSS Filters.
   */
  static bool CSSFiltersEnabled();

  /**
   * Checks if we should enable parsing for CSS clip-path basic shapes.
   */
  static bool CSSClipPathShapesEnabled();

  /**
   * Checks whether support for the CSS-wide "unset" value is enabled.
   */
  static bool UnsetValueEnabled();

  /**
   * Checks whether support for the CSS grid-template-{columns,rows} 'subgrid X'
   * value is enabled.
   */
  static bool IsGridTemplateSubgridValueEnabled();

  /**
   * Checks whether support for the CSS text-align (and text-align-last)
   * 'true' value is enabled.
   */
  static bool IsTextAlignUnsafeValueEnabled();

  static bool InterruptibleReflowEnabled()
  {
    return sInterruptibleReflowEnabled;
  }

  /**
   * Unions the overflow areas of the children of aFrame with aOverflowAreas.
   * aSkipChildLists specifies any child lists that should be skipped.
   * kSelectPopupList and kPopupList are always skipped.
   */
  static void UnionChildOverflow(nsIFrame* aFrame,
                                 nsOverflowAreas& aOverflowAreas,
                                 mozilla::layout::FrameChildListIDs aSkipChildLists =
                                     mozilla::layout::FrameChildListIDs());

  /**
   * Return the font size inflation *ratio* for a given frame.  This is
   * the factor by which font sizes should be inflated; it is never
   * smaller than 1.
   */
  static float FontSizeInflationFor(const nsIFrame *aFrame);

  /**
   * Perform the first half of the computation of FontSizeInflationFor
   * (see above).
   * This includes determining whether inflation should be performed
   * within this container and returning 0 if it should not be.
   *
   * The result is guaranteed not to vary between line participants
   * (inlines, text frames) within a line.
   *
   * The result should not be used directly since font sizes slightly
   * above the minimum should always be adjusted as done by
   * FontSizeInflationInner.
   */
  static nscoord InflationMinFontSizeFor(const nsIFrame *aFrame);

  /**
   * Perform the second half of the computation done by
   * FontSizeInflationFor (see above).
   *
   * aMinFontSize must be the result of one of the
   *   InflationMinFontSizeFor methods above.
   */
  static float FontSizeInflationInner(const nsIFrame *aFrame,
                                      nscoord aMinFontSize);

  static bool FontSizeInflationEnabled(nsPresContext *aPresContext);

  /**
   * See comment above "font.size.inflation.maxRatio" in
   * modules/libpref/src/init/all.js .
   */
  static uint32_t FontSizeInflationMaxRatio() {
    return sFontSizeInflationMaxRatio;
  }

  /**
   * See comment above "font.size.inflation.emPerLine" in
   * modules/libpref/src/init/all.js .
   */
  static uint32_t FontSizeInflationEmPerLine() {
    return sFontSizeInflationEmPerLine;
  }

  /**
   * See comment above "font.size.inflation.minTwips" in
   * modules/libpref/src/init/all.js .
   */
  static uint32_t FontSizeInflationMinTwips() {
    return sFontSizeInflationMinTwips;
  }

  /**
   * See comment above "font.size.inflation.lineThreshold" in
   * modules/libpref/src/init/all.js .
   */
  static uint32_t FontSizeInflationLineThreshold() {
    return sFontSizeInflationLineThreshold;
  }

  static bool FontSizeInflationForceEnabled() {
    return sFontSizeInflationForceEnabled;
  }

  static bool FontSizeInflationDisabledInMasterProcess() {
    return sFontSizeInflationDisabledInMasterProcess;
  }

  /**
   * See comment above "font.size.systemFontScale" in
   * modules/libpref/init/all.js.
   */
  static float SystemFontScale() {
    return sSystemFontScale / 100.0f;
  }

  static float MaxZoom() {
    return sZoomMaxPercent / 100.0f;
  }

  static float MinZoom() {
    return sZoomMinPercent / 100.0f;
  }

  static bool SVGTransformBoxEnabled() {
    return sSVGTransformBoxEnabled;
  }

  static bool TextCombineUprightDigitsEnabled() {
    return sTextCombineUprightDigitsEnabled;
  }

  // Stylo (the Servo backend for Gecko's style system) is generally enabled
  // or disabled at compile-time. However, we provide the additional capability
  // to disable it dynamically in stylo-enabled builds via a pref.
  static bool StyloEnabled() {
#ifdef MOZ_STYLO
    return sStyloEnabled;
#else
    return false;
#endif
  }

  static bool StyleAttrWithXMLBaseDisabled() {
    return sStyleAttrWithXMLBaseDisabled;
  }

  static uint32_t IdlePeriodDeadlineLimit() {
    return sIdlePeriodDeadlineLimit;
  }

  static uint32_t QuiescentFramesBeforeIdlePeriod() {
    return sQuiescentFramesBeforeIdlePeriod;
  }

  /**
   * See comment above "font.size.inflation.mappingIntercept" in
   * modules/libpref/src/init/all.js .
   */
  static int32_t FontSizeInflationMappingIntercept() {
    return sFontSizeInflationMappingIntercept;
  }

  /**
   * Returns true if the nglayout.debug.invalidation pref is set to true.
   * Note that sInvalidationDebuggingIsEnabled is declared outside this function to
   * allow it to be accessed an manipulated from breakpoint conditions.
   */
  static bool InvalidationDebuggingIsEnabled() {
    return sInvalidationDebuggingIsEnabled || getenv("MOZ_DUMP_INVALIDATION") != 0;
  }

  static void Initialize();
  static void Shutdown();

  /**
   * Register an imgIRequest object with a refresh driver.
   *
   * @param aPresContext The nsPresContext whose refresh driver we want to
   *        register with.
   * @param aRequest A pointer to the imgIRequest object which the client wants
   *        to register with the refresh driver.
   * @param aRequestRegistered A pointer to a boolean value which indicates
   *        whether the given image request is registered. If
   *        *aRequestRegistered is true, then this request will not be
   *        registered again. If the request is registered by this function,
   *        then *aRequestRegistered will be set to true upon the completion of
   *        this function.
   *
   */
  static void RegisterImageRequest(nsPresContext* aPresContext,
                                   imgIRequest* aRequest,
                                   bool* aRequestRegistered);

  /**
   * Register an imgIRequest object with a refresh driver, but only if the
   * request is for an image that is animated.
   *
   * @param aPresContext The nsPresContext whose refresh driver we want to
   *        register with.
   * @param aRequest A pointer to the imgIRequest object which the client wants
   *        to register with the refresh driver.
   * @param aRequestRegistered A pointer to a boolean value which indicates
   *        whether the given image request is registered. If
   *        *aRequestRegistered is true, then this request will not be
   *        registered again. If the request is registered by this function,
   *        then *aRequestRegistered will be set to true upon the completion of
   *        this function.
   *
   */
  static void RegisterImageRequestIfAnimated(nsPresContext* aPresContext,
                                             imgIRequest* aRequest,
                                             bool* aRequestRegistered);

  /**
   * Deregister an imgIRequest object from a refresh driver.
   *
   * @param aPresContext The nsPresContext whose refresh driver we want to
   *        deregister from.
   * @param aRequest A pointer to the imgIRequest object with which the client
   *        previously registered and now wants to deregister from the refresh
   *        driver.
   * @param aRequestRegistered A pointer to a boolean value which indicates
   *        whether the given image request is registered. If
   *        *aRequestRegistered is false, then this request will not be
   *        deregistered. If the request is deregistered by this function,
   *        then *aRequestRegistered will be set to false upon the completion of
   *        this function.
   */
  static void DeregisterImageRequest(nsPresContext* aPresContext,
                                     imgIRequest* aRequest,
                                     bool* aRequestRegistered);

  /**
   * Shim to nsCSSFrameConstructor::PostRestyleEvent. Exists so that we
   * can avoid including nsCSSFrameConstructor.h and all its dependencies
   * in content files.
   */
  static void PostRestyleEvent(mozilla::dom::Element* aElement,
                               nsRestyleHint aRestyleHint,
                               nsChangeHint aMinChangeHint);

  /**
   * Updates a pair of x and y distances if a given point is closer to a given
   * rectangle than the original distance values.  If aPoint is closer to
   * aRect than aClosestXDistance and aClosestYDistance indicate, then those
   * two variables are updated with the distance between aPoint and aRect,
   * and true is returned.  If aPoint is not closer, then aClosestXDistance
   * and aClosestYDistance are left unchanged, and false is returned.
   *
   * Distances are measured in the two dimensions separately; a closer x
   * distance beats a closer y distance.
   */
  template<typename PointType, typename RectType, typename CoordType>
  static bool PointIsCloserToRect(PointType aPoint, const RectType& aRect,
                                  CoordType& aClosestXDistance,
                                  CoordType& aClosestYDistance);
  /**
   * Computes the box shadow rect for the frame, or returns an empty rect if
   * there are no shadows.
   *
   * @param aFrame Frame to compute shadows for.
   * @param aFrameSize Size of aFrame (in case it hasn't been set yet).
   */
  static nsRect GetBoxShadowRectForFrame(nsIFrame* aFrame, const nsSize& aFrameSize);

#ifdef DEBUG
  /**
   * Assert that there are no duplicate continuations of the same frame
   * within aFrameList.  Optimize the tests by assuming that all frames
   * in aFrameList have parent aContainer.
   */
  static void
  AssertNoDuplicateContinuations(nsIFrame* aContainer,
                                 const nsFrameList& aFrameList);

  /**
   * Assert that the frame tree rooted at |aSubtreeRoot| is empty, i.e.,
   * that it contains no first-in-flows.
   */
  static void
  AssertTreeOnlyEmptyNextInFlows(nsIFrame *aSubtreeRoot);
#endif

  /**
   * Helper method to get touch action behaviour from the frame
   */
  static uint32_t
  GetTouchActionFromFrame(nsIFrame* aFrame);

  /**
   * Helper method to transform |aBounds| from aFrame to aAncestorFrame,
   * and combine it with |aPreciseTargetDest| if it is axis-aligned, or
   * combine it with |aImpreciseTargetDest| if not. The transformed rect is
   * clipped to |aClip|; if |aClip| has rounded corners, that also causes
   * the imprecise target to be used.
   */
  static void
  TransformToAncestorAndCombineRegions(
    const nsRegion& aRegion,
    nsIFrame* aFrame,
    const nsIFrame* aAncestorFrame,
    nsRegion* aPreciseTargetDest,
    nsRegion* aImpreciseTargetDest,
    mozilla::Maybe<Matrix4x4>* aMatrixCache,
    const mozilla::DisplayItemClip* aClip);

  /**
   * Populate aOutSize with the size of the content viewer corresponding
   * to the given prescontext. Return true if the size was set, false
   * otherwise.
   */
  static bool
  GetContentViewerSize(nsPresContext* aPresContext,
                       LayoutDeviceIntSize& aOutSize);

 /**
  * Calculate the compostion size for a frame. See FrameMetrics.h for
  * defintion of composition size (or bounds).
  * Note that for the root content document's root scroll frame (RCD-RSF),
  * the returned size does not change as the document's resolution changes,
  * but for all other frames it does. This means that callers that pass in
  * a frame that may or may not be the RCD-RSF (which is most callers),
  * are likely to need special-case handling of the RCD-RSF.
  */
  static nsSize
  CalculateCompositionSizeForFrame(nsIFrame* aFrame, bool aSubtractScrollbars = true);

 /**
  * Calculate the composition size for the root scroll frame of the root
  * content document.
  * @param aFrame A frame in the root content document (or a descendant of it).
  * @param aIsRootContentDocRootScrollFrame Whether aFrame is already the root
  *          scroll frame of the root content document. In this case we just
  *          use aFrame's own composition size.
  * @param aMetrics A partially populated FrameMetrics for aFrame. Must have at
  *          least mCompositionBounds, mCumulativeResolution, and
  *          mDevPixelsPerCSSPixel set.
  */
  static CSSSize
  CalculateRootCompositionSize(nsIFrame* aFrame,
                               bool aIsRootContentDocRootScrollFrame,
                               const FrameMetrics& aMetrics);

 /**
  * Calculate the scrollable rect for a frame. See FrameMetrics.h for
  * defintion of scrollable rect. aScrollableFrame is the scroll frame to calculate
  * the scrollable rect for. If it's null then we calculate the scrollable rect
  * as the rect of the root frame.
  */
  static nsRect
  CalculateScrollableRectForFrame(nsIScrollableFrame* aScrollableFrame, nsIFrame* aRootFrame);

 /**
  * Calculate the expanded scrollable rect for a frame. See FrameMetrics.h for
  * defintion of expanded scrollable rect.
  */
  static nsRect
  CalculateExpandedScrollableRect(nsIFrame* aFrame);

  /**
   * Returns true if the widget owning the given frame uses asynchronous
   * scrolling.
   */
  static bool UsesAsyncScrolling(nsIFrame* aFrame);

  /**
   * Returns true if the widget owning the given frame has builtin APZ support
   * enabled.
   */
  static bool AsyncPanZoomEnabled(nsIFrame* aFrame);

  /**
   * Returns the current APZ Resolution Scale. When Java Pan/Zoom is
   * enabled in Fennec it will always return 1.0.
   */
  static float GetCurrentAPZResolutionScale(nsIPresShell* aShell);

  /**
   * Returns true if we need to disable async scrolling for this particular
   * element. Note that this does a partial disabling - the displayport still
   * exists but uses a very small margin, and the compositor doesn't apply the
   * async transform. However, the content may still be layerized.
   */
  static bool ShouldDisableApzForElement(nsIContent* aContent);

  /**
   * Log a key/value pair for APZ testing during a paint.
   * @param aManager   The data will be written to the APZTestData associated
   *                   with this layer manager.
   * @param aScrollId Identifies the scroll frame to which the data pertains.
   * @param aKey The key under which to log the data.
   * @param aValue The value of the data to be logged.
   */
  static void LogTestDataForPaint(mozilla::layers::LayerManager* aManager,
                                  ViewID aScrollId,
                                  const std::string& aKey,
                                  const std::string& aValue) {
    DoLogTestDataForPaint(aManager, aScrollId, aKey, aValue);
  }

  /**
   * A convenience overload of LogTestDataForPaint() that accepts any type
   * as the value, and passes it through mozilla::ToString() to obtain a string
   * value. The type passed must support streaming to an std::ostream.
   */
  template <typename Value>
  static void LogTestDataForPaint(mozilla::layers::LayerManager* aManager,
                                  ViewID aScrollId,
                                  const std::string& aKey,
                                  const Value& aValue) {
    DoLogTestDataForPaint(aManager, aScrollId, aKey,
                          mozilla::ToString(aValue));
  }

  /**
   * Calculate a basic FrameMetrics with enough fields set to perform some
   * layout calculations. The fields set are dev-to-css ratio, pres shell
   * resolution, cumulative resolution, zoom, composition size, root
   * composition size, scroll offset and scrollable rect.
   *
   * By contrast, ComputeFrameMetrics() computes all the fields, but requires
   * extra inputs and can only be called during frame layer building.
   */
  static FrameMetrics CalculateBasicFrameMetrics(nsIScrollableFrame* aScrollFrame);

  /**
   * Calculate a default set of displayport margins for the given scrollframe
   * and set them on the scrollframe's content element. The margins are set with
   * the default priority, which may clobber previously set margins. The repaint
   * mode provided is passed through to the call to SetDisplayPortMargins.
   * The |aScrollFrame| parameter must be non-null and queryable to an nsIFrame.
   * @return true iff the call to SetDisplayPortMargins returned true.
   */
  static bool CalculateAndSetDisplayPortMargins(nsIScrollableFrame* aScrollFrame,
                                                RepaintMode aRepaintMode);

  /**
   * If |aScrollFrame| WantsAsyncScroll() and we don't have a scrollable
   * displayport yet (as tracked by |aBuilder|), calculate and set a
   * displayport.
   *
   * This is intended to be called during display list building.
   */
  static void MaybeCreateDisplayPort(nsDisplayListBuilder& aBuilder,
                                     nsIFrame* aScrollFrame);

  static nsIScrollableFrame* GetAsyncScrollableAncestorFrame(nsIFrame* aTarget);

  /**
   * Sets a zero margin display port on all proper ancestors of aFrame that
   * are async scrollable.
   */
  static void SetZeroMarginDisplayPortOnAsyncScrollableAncestors(nsIFrame* aFrame,
                                                                 RepaintMode aRepaintMode);
  /**
   * Finds the closest ancestor async scrollable frame from aFrame that has a
   * displayport and attempts to trigger the displayport expiry on that
   * ancestor.
   */
  static void ExpireDisplayPortOnAsyncScrollableAncestor(nsIFrame* aFrame);

  static bool IsOutlineStyleAutoEnabled();

  static void SetBSizeFromFontMetrics(const nsIFrame* aFrame,
                                      mozilla::ReflowOutput& aMetrics,
                                      const mozilla::LogicalMargin& aFramePadding,
                                      mozilla::WritingMode aLineWM,
                                      mozilla::WritingMode aFrameWM);

  static bool HasDocumentLevelListenersForApzAwareEvents(nsIPresShell* aShell);

  /**
   * Set the scroll port size for the purpose of clamping the scroll position
   * for the root scroll frame of this document
   * (see nsIDOMWindowUtils.setScrollPositionClampingScrollPortSize).
   */
  static void SetScrollPositionClampingScrollPortSize(nsIPresShell* aPresShell,
                                                      CSSSize aSize);

  /**
   * Returns true if the given scroll origin is "higher priority" than APZ.
   * In general any content programmatic scrolls (e.g. scrollTo calls) are
   * higher priority, and take precedence over APZ scrolling. This function
   * returns true for those, and returns false for other origins like APZ
   * itself, or scroll position updates from the history restore code.
   */
  static bool CanScrollOriginClobberApz(nsIAtom* aScrollOrigin);

  static ScrollMetadata ComputeScrollMetadata(nsIFrame* aForFrame,
                                              nsIFrame* aScrollFrame,
                                              nsIContent* aContent,
                                              const nsIFrame* aReferenceFrame,
                                              Layer* aLayer,
                                              ViewID aScrollParentId,
                                              const nsRect& aViewport,
                                              const mozilla::Maybe<nsRect>& aClipRect,
                                              bool aIsRoot,
                                              const ContainerLayerParameters& aContainerParameters);

  /**
   * If the given scroll frame needs an area excluded from its composition
   * bounds due to scrollbars, return that area, otherwise return an empty
   * margin.
   * There is no need to exclude scrollbars in the following cases:
   *   - If the scroll frame is not the RCD-RSF; in that case, the composition
   *     bounds is calculated based on the scroll port which already excludes
   *     the scrollbar area.
   *   - If the scrollbars are overlay, since then they are drawn on top of the
   *     scrollable content.
   */
  static nsMargin ScrollbarAreaToExcludeFromCompositionBoundsFor(nsIFrame* aScrollFrame);

  /**
   * Looks in the layer subtree rooted at aLayer for a metrics with scroll id
   * aScrollId. Returns true if such is found.
   */
  static bool ContainsMetricsWithId(const Layer* aLayer, const ViewID& aScrollId);

  static bool ShouldUseNoScriptSheet(nsIDocument* aDocument);
  static bool ShouldUseNoFramesSheet(nsIDocument* aDocument);

  /**
   * Get the text content inside the frame. This methods traverse the
   * frame tree and collect the content from text frames. Note that this
   * method is similiar to nsContentUtils::GetNodeTextContent, but it at
   * least differs from that method in the following things:
   * 1. it skips text content inside nodes like style, script, textarea
   *    which don't generate an in-tree text frame for the text;
   * 2. it skips elements with display property set to none;
   * 3. it skips out-of-flow elements;
   * 4. it includes content inside pseudo elements;
   * 5. it may include part of text content of a node if a text frame
   *    inside is split to different continuations.
   */
  static void GetFrameTextContent(nsIFrame* aFrame, nsAString& aResult);

  /**
   * Same as GetFrameTextContent but appends the result rather than sets it.
   */
  static void AppendFrameTextContent(nsIFrame* aFrame, nsAString& aResult);

  /**
   * Takes a selection, and returns selection's bounding rect which is relative
   * to its root frame.
   *
   * @param aSel      Selection to check
   */
  static nsRect GetSelectionBoundingRect(mozilla::dom::Selection* aSel);

  /**
   * Calculate the bounding rect of |aContent|, relative to the origin
   * of the scrolled content of |aRootScrollFrame|.
   * Where the element is contained inside a scrollable subframe, the
   * bounding rect is clipped to the bounds of the subframe.
   */
  static CSSRect GetBoundingContentRect(const nsIContent* aContent,
                                        const nsIScrollableFrame* aRootScrollFrame);

  /**
   * Returns the first ancestor who is a float containing block.
   */
  static nsBlockFrame* GetFloatContainingBlock(nsIFrame* aFrame);

  /**
   * Walks up the frame tree from |aForFrame| up to |aTopFrame|, or to the
   * root of the frame tree if |aTopFrame| is nullptr, and returns true if
   * a transformed frame is encountered.
   */
  static bool IsTransformed(nsIFrame* aForFrame, nsIFrame* aTopFrame = nullptr);

  /**
   * Walk up from aFrame to the cross-doc root, accumulating all the APZ callback
   * transforms on the content elements encountered along the way. Return the
   * accumulated value.
   * XXX: Note that this does not take into account CSS transforms, nor
   * differences in structure between the frame tree and the layer tree (which
   * is probably what we *want* to be computing).
   */
  static CSSPoint GetCumulativeApzCallbackTransform(nsIFrame* aFrame);

  /**
   * Compute a rect to pre-render in cases where we want to render more of
   * something than what is visible (usually to support async transformation).
   * @param aDirtyRect the area that's visible
   * @param aOverflow the total size of the thing we're rendering
   * @param aPrerenderSize how large of an area we're willing to render
   * @return A rectangle that includes |aDirtyRect|, is clamped to |aOverflow|,
   *         and is no larger than |aPrerenderSize|.
   */
  static nsRect ComputePartialPrerenderArea(const nsRect& aDirtyRect,
                                            const nsRect& aOverflow,
                                            const nsSize& aPrerenderSize);

  /*
   * Checks whether a node is an invisible break.
   * If not, returns the first frame on the next line if such a next line exists.
   *
   * @return  true if the node is an invisible break.
   *          aNextLineFrame is returned null in this case.
   *          false if the node causes a visible break or if the node is no break.
   *
   * @param   aNextLineFrame  assigned to first frame on the next line if such a
   *                          next line exists, null otherwise.
   */
  static bool IsInvisibleBreak(nsINode* aNode, nsIFrame** aNextLineFrame = nullptr);

  static nsRect ComputeGeometryBox(nsIFrame* aFrame,
                                   StyleGeometryBox aGeometryBox);

private:
  static uint32_t sFontSizeInflationEmPerLine;
  static uint32_t sFontSizeInflationMinTwips;
  static uint32_t sFontSizeInflationLineThreshold;
  static int32_t  sFontSizeInflationMappingIntercept;
  static uint32_t sFontSizeInflationMaxRatio;
  static bool sFontSizeInflationForceEnabled;
  static bool sFontSizeInflationDisabledInMasterProcess;
  static uint32_t sSystemFontScale;
  static uint32_t sZoomMaxPercent;
  static uint32_t sZoomMinPercent;
  static bool sInvalidationDebuggingIsEnabled;
  static bool sInterruptibleReflowEnabled;
  static bool sSVGTransformBoxEnabled;
  static bool sTextCombineUprightDigitsEnabled;
#ifdef MOZ_STYLO
  static bool sStyloEnabled;
#endif
  static bool sStyleAttrWithXMLBaseDisabled;
  static uint32_t sIdlePeriodDeadlineLimit;
  static uint32_t sQuiescentFramesBeforeIdlePeriod;

  /**
   * Helper function for LogTestDataForPaint().
   */
  static void DoLogTestDataForPaint(mozilla::layers::LayerManager* aManager,
                                    ViewID aScrollId,
                                    const std::string& aKey,
                                    const std::string& aValue);

  static bool IsAPZTestLoggingEnabled();
};

MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(nsLayoutUtils::PaintFrameFlags)

template<typename PointType, typename RectType, typename CoordType>
/* static */ bool
nsLayoutUtils::PointIsCloserToRect(PointType aPoint, const RectType& aRect,
                                   CoordType& aClosestXDistance,
                                   CoordType& aClosestYDistance)
{
  CoordType fromLeft = aPoint.x - aRect.x;
  CoordType fromRight = aPoint.x - aRect.XMost();

  CoordType xDistance;
  if (fromLeft >= 0 && fromRight <= 0) {
    xDistance = 0;
  } else {
    xDistance = std::min(abs(fromLeft), abs(fromRight));
  }

  if (xDistance <= aClosestXDistance) {
    if (xDistance < aClosestXDistance) {
      aClosestYDistance = std::numeric_limits<CoordType>::max();
    }

    CoordType fromTop = aPoint.y - aRect.y;
    CoordType fromBottom = aPoint.y - aRect.YMost();

    CoordType yDistance;
    if (fromTop >= 0 && fromBottom <= 0) {
      yDistance = 0;
    } else {
      yDistance = std::min(abs(fromTop), abs(fromBottom));
    }

    if (yDistance < aClosestYDistance) {
      aClosestXDistance = xDistance;
      aClosestYDistance = yDistance;
      return true;
    }
  }

  return false;
}

namespace mozilla {

/**
 * Converts an nsPoint in app units to a Moz2D Point in pixels (whether those
 * are device pixels or CSS px depends on what the caller chooses to pass as
 * aAppUnitsPerPixel).
 */
inline gfx::Point NSPointToPoint(const nsPoint& aPoint,
                                 int32_t aAppUnitsPerPixel) {
  return gfx::Point(gfx::Float(aPoint.x) / aAppUnitsPerPixel,
                    gfx::Float(aPoint.y) / aAppUnitsPerPixel);
}

/**
 * Converts an nsRect in app units to a Moz2D Rect in pixels (whether those
 * are device pixels or CSS px depends on what the caller chooses to pass as
 * aAppUnitsPerPixel).
 */
gfx::Rect NSRectToRect(const nsRect& aRect, double aAppUnitsPerPixel);

/**
 * Converts an nsRect in app units to a Moz2D Rect in pixels (whether those
 * are device pixels or CSS px depends on what the caller chooses to pass as
 * aAppUnitsPerPixel).
 *
 * The passed DrawTarget is used to additionally snap the returned Rect to
 * device pixels, if appropriate (as decided and carried out by Moz2D's
 * MaybeSnapToDevicePixels helper, which this function calls to do any
 * snapping).
 */
gfx::Rect NSRectToSnappedRect(const nsRect& aRect, double aAppUnitsPerPixel,
                              const gfx::DrawTarget& aSnapDT);

/**
* Converts, where possible, an nsRect in app units to a Moz2D Rect in pixels
* (whether those are device pixels or CSS px depends on what the caller
*  chooses to pass as aAppUnitsPerPixel).
*
* If snapping results in a rectangle with zero width or height, the affected
* coordinates are left unsnapped
*/
gfx::Rect NSRectToNonEmptySnappedRect(const nsRect& aRect, double aAppUnitsPerPixel,
                                      const gfx::DrawTarget& aSnapDT);

void StrokeLineWithSnapping(const nsPoint& aP1, const nsPoint& aP2,
                            int32_t aAppUnitsPerDevPixel,
                            gfx::DrawTarget& aDrawTarget,
                            const gfx::Pattern& aPattern,
                            const gfx::StrokeOptions& aStrokeOptions = gfx::StrokeOptions(),
                            const gfx::DrawOptions& aDrawOptions = gfx::DrawOptions());

  namespace layout {

    /**
     * An RAII class which will, for the duration of its lifetime,
     * **if** the frame given is a container for font size inflation,
     * set the current inflation container on the pres context to null
     * (and then, in its destructor, restore the old value).
     */
    class AutoMaybeDisableFontInflation {
    public:
      explicit AutoMaybeDisableFontInflation(nsIFrame *aFrame);

      ~AutoMaybeDisableFontInflation();
    private:
      nsPresContext *mPresContext;
      bool mOldValue;
    };

    void MaybeSetupTransactionIdAllocator(layers::LayerManager* aManager,
                                          nsPresContext* aPresContext);

  } // namespace layout
} // namespace mozilla

class nsSetAttrRunnable : public mozilla::Runnable
{
public:
  nsSetAttrRunnable(nsIContent* aContent, nsIAtom* aAttrName,
                    const nsAString& aValue);
  nsSetAttrRunnable(nsIContent* aContent, nsIAtom* aAttrName,
                    int32_t aValue);

  NS_DECL_NSIRUNNABLE

  nsCOMPtr<nsIContent> mContent;
  nsCOMPtr<nsIAtom> mAttrName;
  nsAutoString mValue;
};

class nsUnsetAttrRunnable : public mozilla::Runnable
{
public:
  nsUnsetAttrRunnable(nsIContent* aContent, nsIAtom* aAttrName);

  NS_DECL_NSIRUNNABLE

  nsCOMPtr<nsIContent> mContent;
  nsCOMPtr<nsIAtom> mAttrName;
};

#endif // nsLayoutUtils_h__