DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

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
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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/. */

#include "mozilla/dom/HTMLImageElement.h"
#include "mozilla/dom/HTMLImageElementBinding.h"
#include "nsGkAtoms.h"
#include "nsStyleConsts.h"
#include "nsPresContext.h"
#include "nsMappedAttributes.h"
#include "nsSize.h"
#include "nsDocument.h"
#include "nsIDocument.h"
#include "nsIDOMMutationEvent.h"
#include "nsIScriptContext.h"
#include "nsIURL.h"
#include "nsIIOService.h"
#include "nsIServiceManager.h"
#include "nsContentUtils.h"
#include "nsContainerFrame.h"
#include "nsNodeInfoManager.h"
#include "mozilla/MouseEvents.h"
#include "nsContentPolicyUtils.h"
#include "nsIDOMWindow.h"
#include "nsFocusManager.h"
#include "mozilla/dom/HTMLFormElement.h"
#include "nsAttrValueOrString.h"
#include "imgLoader.h"
#include "Image.h"

// Responsive images!
#include "mozilla/dom/HTMLSourceElement.h"
#include "mozilla/dom/ResponsiveImageSelector.h"

#include "imgIContainer.h"
#include "imgILoader.h"
#include "imgINotificationObserver.h"
#include "imgRequestProxy.h"

#include "nsILoadGroup.h"

#include "nsRuleData.h"

#include "nsIDOMHTMLMapElement.h"
#include "mozilla/EventDispatcher.h"
#include "mozilla/EventStates.h"
#include "mozilla/net/ReferrerPolicy.h"

#include "nsLayoutUtils.h"

using namespace mozilla::net;

NS_IMPL_NS_NEW_HTML_ELEMENT(Image)

#ifdef DEBUG
// Is aSubject a previous sibling of aNode.
static bool IsPreviousSibling(nsINode *aSubject, nsINode *aNode)
{
  if (aSubject == aNode) {
    return false;
  }

  nsINode *parent = aSubject->GetParentNode();
  if (parent && parent == aNode->GetParentNode()) {
    return parent->IndexOf(aSubject) < parent->IndexOf(aNode);
  }

  return false;
}
#endif

namespace mozilla {
namespace dom {

// Calls LoadSelectedImage on host element unless it has been superseded or
// canceled -- this is the synchronous section of "update the image data".
// https://html.spec.whatwg.org/multipage/embedded-content.html#update-the-image-data
class ImageLoadTask : public Runnable
{
public:
  ImageLoadTask(HTMLImageElement *aElement, bool aAlwaysLoad)
    : mElement(aElement)
    , mAlwaysLoad(aAlwaysLoad)
  {
    mDocument = aElement->OwnerDoc();
    mDocument->BlockOnload();
  }

  NS_IMETHOD Run() override
  {
    if (mElement->mPendingImageLoadTask == this) {
      mElement->mPendingImageLoadTask = nullptr;
      mElement->LoadSelectedImage(true, true, mAlwaysLoad);
    }
    mDocument->UnblockOnload(false);
    return NS_OK;
  }

  bool AlwaysLoad() {
    return mAlwaysLoad;
  }

private:
  ~ImageLoadTask() {}
  RefPtr<HTMLImageElement> mElement;
  nsCOMPtr<nsIDocument> mDocument;
  bool mAlwaysLoad;
};

HTMLImageElement::HTMLImageElement(already_AddRefed<mozilla::dom::NodeInfo>& aNodeInfo)
  : nsGenericHTMLElement(aNodeInfo)
  , mForm(nullptr)
  , mInDocResponsiveContent(false)
  , mCurrentDensity(1.0)
{
  // We start out broken
  AddStatesSilently(NS_EVENT_STATE_BROKEN);
}

HTMLImageElement::~HTMLImageElement()
{
  DestroyImageLoadingContent();
}


NS_IMPL_ADDREF_INHERITED(HTMLImageElement, Element)
NS_IMPL_RELEASE_INHERITED(HTMLImageElement, Element)

NS_IMPL_CYCLE_COLLECTION_INHERITED(HTMLImageElement,
                                   nsGenericHTMLElement,
                                   mResponsiveSelector)

// QueryInterface implementation for HTMLImageElement
NS_INTERFACE_TABLE_HEAD_CYCLE_COLLECTION_INHERITED(HTMLImageElement)
  NS_INTERFACE_TABLE_INHERITED(HTMLImageElement,
                               nsIDOMHTMLImageElement,
                               nsIImageLoadingContent,
                               imgIOnloadBlocker,
                               imgINotificationObserver)
NS_INTERFACE_TABLE_TAIL_INHERITING(nsGenericHTMLElement)


NS_IMPL_ELEMENT_CLONE(HTMLImageElement)


NS_IMPL_STRING_ATTR(HTMLImageElement, Name, name)
NS_IMPL_STRING_ATTR(HTMLImageElement, Align, align)
NS_IMPL_STRING_ATTR(HTMLImageElement, Alt, alt)
NS_IMPL_STRING_ATTR(HTMLImageElement, Border, border)
NS_IMPL_INT_ATTR(HTMLImageElement, Hspace, hspace)
NS_IMPL_BOOL_ATTR(HTMLImageElement, IsMap, ismap)
NS_IMPL_URI_ATTR(HTMLImageElement, LongDesc, longdesc)
NS_IMPL_STRING_ATTR(HTMLImageElement, Sizes, sizes)
NS_IMPL_URI_ATTR(HTMLImageElement, Lowsrc, lowsrc)
NS_IMPL_URI_ATTR(HTMLImageElement, Src, src)
NS_IMPL_STRING_ATTR(HTMLImageElement, Srcset, srcset)
NS_IMPL_STRING_ATTR(HTMLImageElement, UseMap, usemap)
NS_IMPL_INT_ATTR(HTMLImageElement, Vspace, vspace)

bool
HTMLImageElement::IsInteractiveHTMLContent(bool aIgnoreTabindex) const
{
  return HasAttr(kNameSpaceID_None, nsGkAtoms::usemap) ||
          nsGenericHTMLElement::IsInteractiveHTMLContent(aIgnoreTabindex);
}

void
HTMLImageElement::AsyncEventRunning(AsyncEventDispatcher* aEvent)
{
  nsImageLoadingContent::AsyncEventRunning(aEvent);
}

nsresult
HTMLImageElement::GetCurrentSrc(nsAString& aValue)
{
  nsCOMPtr<nsIURI> currentURI;
  GetCurrentURI(getter_AddRefs(currentURI));
  if (currentURI) {
    nsAutoCString spec;
    currentURI->GetSpec(spec);
    CopyUTF8toUTF16(spec, aValue);
  } else {
    SetDOMStringToNull(aValue);
  }

  return NS_OK;
}

bool
HTMLImageElement::Draggable() const
{
  // images may be dragged unless the draggable attribute is false
  return !AttrValueIs(kNameSpaceID_None, nsGkAtoms::draggable,
                      nsGkAtoms::_false, eIgnoreCase);
}

bool
HTMLImageElement::Complete()
{
  if (!mCurrentRequest) {
    return true;
  }

  if (mPendingRequest) {
    return false;
  }

  uint32_t status;
  mCurrentRequest->GetImageStatus(&status);
  return
    (status &
     (imgIRequest::STATUS_LOAD_COMPLETE | imgIRequest::STATUS_ERROR)) != 0;
}

NS_IMETHODIMP
HTMLImageElement::GetComplete(bool* aComplete)
{
  NS_PRECONDITION(aComplete, "Null out param!");

  *aComplete = Complete();

  return NS_OK;
}

CSSIntPoint
HTMLImageElement::GetXY()
{
  nsIFrame* frame = GetPrimaryFrame(Flush_Layout);
  if (!frame) {
    return CSSIntPoint(0, 0);
  }

  nsIFrame* layer = nsLayoutUtils::GetClosestLayer(frame->GetParent());
  return CSSIntPoint::FromAppUnitsRounded(frame->GetOffsetTo(layer));
}

int32_t
HTMLImageElement::X()
{
  return GetXY().x;
}

int32_t
HTMLImageElement::Y()
{
  return GetXY().y;
}

NS_IMETHODIMP
HTMLImageElement::GetX(int32_t* aX)
{
  *aX = X();
  return NS_OK;
}

NS_IMETHODIMP
HTMLImageElement::GetY(int32_t* aY)
{
  *aY = Y();
  return NS_OK;
}

NS_IMETHODIMP
HTMLImageElement::GetHeight(uint32_t* aHeight)
{
  *aHeight = Height();

  return NS_OK;
}

NS_IMETHODIMP
HTMLImageElement::SetHeight(uint32_t aHeight)
{
  ErrorResult rv;
  SetHeight(aHeight, rv);
  return rv.StealNSResult();
}

NS_IMETHODIMP
HTMLImageElement::GetWidth(uint32_t* aWidth)
{
  *aWidth = Width();

  return NS_OK;
}

NS_IMETHODIMP
HTMLImageElement::SetWidth(uint32_t aWidth)
{
  ErrorResult rv;
  SetWidth(aWidth, rv);
  return rv.StealNSResult();
}

bool
HTMLImageElement::ParseAttribute(int32_t aNamespaceID,
                                 nsIAtom* aAttribute,
                                 const nsAString& aValue,
                                 nsAttrValue& aResult)
{
  if (aNamespaceID == kNameSpaceID_None) {
    if (aAttribute == nsGkAtoms::align) {
      return ParseAlignValue(aValue, aResult);
    }
    if (aAttribute == nsGkAtoms::crossorigin) {
      ParseCORSValue(aValue, aResult);
      return true;
    }
    if (ParseImageAttribute(aAttribute, aValue, aResult)) {
      return true;
    }
  }

  return nsGenericHTMLElement::ParseAttribute(aNamespaceID, aAttribute, aValue,
                                              aResult);
}

void
HTMLImageElement::MapAttributesIntoRule(const nsMappedAttributes* aAttributes,
                                        nsRuleData* aData)
{
  nsGenericHTMLElement::MapImageAlignAttributeInto(aAttributes, aData);
  nsGenericHTMLElement::MapImageBorderAttributeInto(aAttributes, aData);
  nsGenericHTMLElement::MapImageMarginAttributeInto(aAttributes, aData);
  nsGenericHTMLElement::MapImageSizeAttributesInto(aAttributes, aData);
  nsGenericHTMLElement::MapCommonAttributesInto(aAttributes, aData);
}

nsChangeHint
HTMLImageElement::GetAttributeChangeHint(const nsIAtom* aAttribute,
                                         int32_t aModType) const
{
  nsChangeHint retval =
    nsGenericHTMLElement::GetAttributeChangeHint(aAttribute, aModType);
  if (aAttribute == nsGkAtoms::usemap ||
      aAttribute == nsGkAtoms::ismap) {
    retval |= nsChangeHint_ReconstructFrame;
  } else if (aAttribute == nsGkAtoms::alt) {
    if (aModType == nsIDOMMutationEvent::ADDITION ||
        aModType == nsIDOMMutationEvent::REMOVAL) {
      retval |= nsChangeHint_ReconstructFrame;
    }
  }
  return retval;
}

NS_IMETHODIMP_(bool)
HTMLImageElement::IsAttributeMapped(const nsIAtom* aAttribute) const
{
  static const MappedAttributeEntry* const map[] = {
    sCommonAttributeMap,
    sImageMarginSizeAttributeMap,
    sImageBorderAttributeMap,
    sImageAlignAttributeMap
  };

  return FindAttributeDependence(aAttribute, map);
}


nsMapRuleToAttributesFunc
HTMLImageElement::GetAttributeMappingFunction() const
{
  return &MapAttributesIntoRule;
}


nsresult
HTMLImageElement::BeforeSetAttr(int32_t aNameSpaceID, nsIAtom* aName,
                                nsAttrValueOrString* aValue,
                                bool aNotify)
{

  if (aNameSpaceID == kNameSpaceID_None && mForm &&
      (aName == nsGkAtoms::name || aName == nsGkAtoms::id)) {
    // remove the image from the hashtable as needed
    nsAutoString tmp;
    GetAttr(kNameSpaceID_None, aName, tmp);

    if (!tmp.IsEmpty()) {
      mForm->RemoveImageElementFromTable(this, tmp,
                                         HTMLFormElement::AttributeUpdated);
    }
  }

  return nsGenericHTMLElement::BeforeSetAttr(aNameSpaceID, aName,
                                             aValue, aNotify);
}

nsresult
HTMLImageElement::AfterSetAttr(int32_t aNameSpaceID, nsIAtom* aName,
                               const nsAttrValue* aValue, bool aNotify)
{
  if (aNameSpaceID == kNameSpaceID_None && mForm &&
      (aName == nsGkAtoms::name || aName == nsGkAtoms::id) &&
      aValue && !aValue->IsEmptyString()) {
    // add the image to the hashtable as needed
    MOZ_ASSERT(aValue->Type() == nsAttrValue::eAtom,
               "Expected atom value for name/id");
    mForm->AddImageElementToTable(this,
      nsDependentAtomString(aValue->GetAtomValue()));
  }

  // Handle src/srcset updates. If aNotify is false, we are coming from the
  // parser or some such place; we'll get bound after all the attributes have
  // been set, so we'll do the image load from BindToTree.

  nsAttrValueOrString attrVal(aValue);

  if (aName == nsGkAtoms::src &&
      aNameSpaceID == kNameSpaceID_None &&
      !aValue) {
    // SetAttr handles setting src since it needs to catch img.src =
    // img.src, so we only need to handle the unset case
    if (InResponsiveMode()) {
      if (mResponsiveSelector &&
          mResponsiveSelector->Content() == this) {
        mResponsiveSelector->SetDefaultSource(NullString());
      }
      QueueImageLoadTask(true);
    } else {
      // Bug 1076583 - We still behave synchronously in the non-responsive case
      CancelImageRequests(aNotify);
    }
  } else if (aName == nsGkAtoms::srcset &&
             aNameSpaceID == kNameSpaceID_None) {
    PictureSourceSrcsetChanged(this, attrVal.String(), aNotify);
  } else if (aName == nsGkAtoms::sizes &&
             aNameSpaceID == kNameSpaceID_None) {
    PictureSourceSizesChanged(this, attrVal.String(), aNotify);
  }

  return nsGenericHTMLElement::AfterSetAttr(aNameSpaceID, aName,
                                            aValue, aNotify);
}

nsresult
HTMLImageElement::PreHandleEvent(EventChainPreVisitor& aVisitor)
{
  // We handle image element with attribute ismap in its corresponding frame
  // element. Set mMultipleActionsPrevented here to prevent the click event
  // trigger the behaviors in Element::PostHandleEventForLinks
  WidgetMouseEvent* mouseEvent = aVisitor.mEvent->AsMouseEvent();
  if (mouseEvent && mouseEvent->IsLeftClickEvent() && IsMap()) {
    mouseEvent->mFlags.mMultipleActionsPrevented = true;
  }
  return nsGenericHTMLElement::PreHandleEvent(aVisitor);
}

bool
HTMLImageElement::IsHTMLFocusable(bool aWithMouse,
                                  bool *aIsFocusable, int32_t *aTabIndex)
{
  int32_t tabIndex = TabIndex();

  if (IsInUncomposedDoc()) {
    nsAutoString usemap;
    GetUseMap(usemap);
    // XXXbz which document should this be using?  sXBL/XBL2 issue!  I
    // think that OwnerDoc() is right, since we don't want to
    // assume stuff about the document we're bound to.
    if (OwnerDoc()->FindImageMap(usemap)) {
      if (aTabIndex) {
        // Use tab index on individual map areas
        *aTabIndex = (sTabFocusModel & eTabFocus_linksMask)? 0 : -1;
      }
      // Image map is not focusable itself, but flag as tabbable
      // so that image map areas get walked into.
      *aIsFocusable = false;

      return false;
    }
  }

  if (aTabIndex) {
    // Can be in tab order if tabindex >=0 and form controls are tabbable.
    *aTabIndex = (sTabFocusModel & eTabFocus_formElementsMask)? tabIndex : -1;
  }

  *aIsFocusable =
#ifdef XP_MACOSX
    (!aWithMouse || nsFocusManager::sMouseFocusesFormControl) &&
#endif
    (tabIndex >= 0 || HasAttr(kNameSpaceID_None, nsGkAtoms::tabindex));

  return false;
}

nsresult
HTMLImageElement::SetAttr(int32_t aNameSpaceID, nsIAtom* aName,
                          nsIAtom* aPrefix, const nsAString& aValue,
                          bool aNotify)
{
  bool forceReload = false;
  // We need to force our image to reload.  This must be done here, not in
  // AfterSetAttr or BeforeSetAttr, because we want to do it even if the attr is
  // being set to its existing value, which is normally optimized away as a
  // no-op.
  //
  // If we are in responsive mode, we drop the forced reload behavior,
  // but still trigger a image load task for img.src = img.src per
  // spec.
  //
  // Both cases handle unsetting src in AfterSetAttr
  if (aNameSpaceID == kNameSpaceID_None &&
      aName == nsGkAtoms::src) {

    if (InResponsiveMode()) {
      if (mResponsiveSelector &&
          mResponsiveSelector->Content() == this) {
        mResponsiveSelector->SetDefaultSource(aValue);
      }
      QueueImageLoadTask(true);
    } else if (aNotify) {
      // If aNotify is false, we are coming from the parser or some such place;
      // we'll get bound after all the attributes have been set, so we'll do the
      // sync image load from BindToTree. Skip the LoadImage call in that case.

      // Note that this sync behavior is partially removed from the spec, bug 1076583

      // A hack to get animations to reset. See bug 594771.
      mNewRequestsWillNeedAnimationReset = true;

      // Force image loading here, so that we'll try to load the image from
      // network if it's set to be not cacheable...  If we change things so that
      // the state gets in Element's attr-setting happen around this
      // LoadImage call, we could start passing false instead of aNotify
      // here.
      LoadImage(aValue, true, aNotify, eImageLoadType_Normal);

      mNewRequestsWillNeedAnimationReset = false;
    }
  } else if (aNameSpaceID == kNameSpaceID_None &&
             aName == nsGkAtoms::crossorigin &&
             aNotify) {
    nsAttrValue attrValue;
    ParseCORSValue(aValue, attrValue);
    if (GetCORSMode() != AttrValueToCORSMode(&attrValue)) {
      // Force a new load of the image with the new cross origin policy.
      forceReload = true;
    }
  } else if (aName == nsGkAtoms::referrerpolicy &&
      aNameSpaceID == kNameSpaceID_None &&
      aNotify) {
    ReferrerPolicy referrerPolicy = AttributeReferrerPolicyFromString(aValue);
    if (!InResponsiveMode() &&
        referrerPolicy != RP_Unset &&
        referrerPolicy != GetImageReferrerPolicy()) {
      // XXX: Bug 1076583 - We still use the older synchronous algorithm
      // Because referrerPolicy is not treated as relevant mutations, setting
      // the attribute will neither trigger a reload nor update the referrer
      // policy of the loading channel (whether it has previously completed or
      // not). Force a new load of the image with the new referrerpolicy.
      forceReload = true;
    }
  }

  nsresult rv = nsGenericHTMLElement::SetAttr(aNameSpaceID, aName, aPrefix,
                                              aValue, aNotify);

  // Because we load image synchronously in non-responsive-mode, we need to do
  // reload after the attribute has been set if the reload is triggerred by
  // cross origin changing.
  if (forceReload) {
    if (InResponsiveMode()) {
      // per spec, full selection runs when this changes, even though
      // it doesn't directly affect the source selection
      QueueImageLoadTask(true);
    } else {
      // Bug 1076583 - We still use the older synchronous algorithm in
      // non-responsive mode. Force a new load of the image with the
      // new cross origin policy
      ForceReload(aNotify);
    }
  }

  return rv;
}

nsresult
HTMLImageElement::BindToTree(nsIDocument* aDocument, nsIContent* aParent,
                             nsIContent* aBindingParent,
                             bool aCompileEventHandlers)
{
  nsresult rv = nsGenericHTMLElement::BindToTree(aDocument, aParent,
                                                 aBindingParent,
                                                 aCompileEventHandlers);
  NS_ENSURE_SUCCESS(rv, rv);

  nsImageLoadingContent::BindToTree(aDocument, aParent, aBindingParent,
                                    aCompileEventHandlers);

  if (aParent) {
    UpdateFormOwner();
  }

  if (HaveSrcsetOrInPicture()) {
    if (aDocument && !mInDocResponsiveContent) {
      aDocument->AddResponsiveContent(this);
      mInDocResponsiveContent = true;
    }

    // Run selection algorithm when an img element is inserted into a document
    // in order to react to changes in the environment. See note of
    // https://html.spec.whatwg.org/multipage/embedded-content.html#img-environment-changes
    QueueImageLoadTask(false);
  } else if (!InResponsiveMode() &&
             HasAttr(kNameSpaceID_None, nsGkAtoms::src)) {
    // We skip loading when our attributes were set from parser land,
    // so trigger a aForce=false load now to check if things changed.
    // This isn't necessary for responsive mode, since creating the
    // image load task is asynchronous we don't need to take special
    // care to avoid doing so when being filled by the parser.

    // FIXME: Bug 660963 it would be nice if we could just have
    // ClearBrokenState update our state and do it fast...
    ClearBrokenState();
    RemoveStatesSilently(NS_EVENT_STATE_BROKEN);

    // We still act synchronously for the non-responsive case (Bug
    // 1076583), but still need to delay if it is unsafe to run
    // script.

    // If loading is temporarily disabled, don't even launch MaybeLoadImage.
    // Otherwise MaybeLoadImage may run later when someone has reenabled
    // loading.
    if (LoadingEnabled()) {
      nsContentUtils::AddScriptRunner(
          NewRunnableMethod(this, &HTMLImageElement::MaybeLoadImage));
    }
  }

  return rv;
}

void
HTMLImageElement::UnbindFromTree(bool aDeep, bool aNullParent)
{
  if (mForm) {
    if (aNullParent || !FindAncestorForm(mForm)) {
      ClearForm(true);
    } else {
      UnsetFlags(MAYBE_ORPHAN_FORM_ELEMENT);
    }
  }

  if (mInDocResponsiveContent) {
    nsIDocument* doc = GetOurOwnerDoc();
    MOZ_ASSERT(doc);
    if (doc) {
      doc->RemoveResponsiveContent(this);
      mInDocResponsiveContent = false;
    }
  }

  mLastSelectedSource = nullptr;

  nsImageLoadingContent::UnbindFromTree(aDeep, aNullParent);
  nsGenericHTMLElement::UnbindFromTree(aDeep, aNullParent);
}

void
HTMLImageElement::UpdateFormOwner()
{
  if (!mForm) {
    mForm = FindAncestorForm();
  }

  if (mForm && !HasFlag(ADDED_TO_FORM)) {
    // Now we need to add ourselves to the form
    nsAutoString nameVal, idVal;
    GetAttr(kNameSpaceID_None, nsGkAtoms::name, nameVal);
    GetAttr(kNameSpaceID_None, nsGkAtoms::id, idVal);

    SetFlags(ADDED_TO_FORM);

    mForm->AddImageElement(this);

    if (!nameVal.IsEmpty()) {
      mForm->AddImageElementToTable(this, nameVal);
    }

    if (!idVal.IsEmpty()) {
      mForm->AddImageElementToTable(this, idVal);
    }
  }
}

void
HTMLImageElement::MaybeLoadImage()
{
  // Our base URI may have changed, or we may have had responsive parameters
  // change while not bound to the tree. Re-parse src/srcset and call LoadImage,
  // which is a no-op if it resolves to the same effective URI without aForce.

  // Note, check LoadingEnabled() after LoadImage call.

  LoadSelectedImage(false, true, false);

  if (!LoadingEnabled()) {
    CancelImageRequests(true);
  }
}

EventStates
HTMLImageElement::IntrinsicState() const
{
  return nsGenericHTMLElement::IntrinsicState() |
    nsImageLoadingContent::ImageState();
}

void
HTMLImageElement::NodeInfoChanged()
{
  // Resetting the last selected source if adoption steps are run.
  mLastSelectedSource = nullptr;
}

// static
already_AddRefed<HTMLImageElement>
HTMLImageElement::Image(const GlobalObject& aGlobal,
                        const Optional<uint32_t>& aWidth,
                        const Optional<uint32_t>& aHeight,
                        ErrorResult& aError)
{
  nsCOMPtr<nsPIDOMWindowInner> win = do_QueryInterface(aGlobal.GetAsSupports());
  nsIDocument* doc;
  if (!win || !(doc = win->GetExtantDoc())) {
    aError.Throw(NS_ERROR_FAILURE);
    return nullptr;
  }

  already_AddRefed<mozilla::dom::NodeInfo> nodeInfo =
    doc->NodeInfoManager()->GetNodeInfo(nsGkAtoms::img, nullptr,
                                        kNameSpaceID_XHTML,
                                        nsIDOMNode::ELEMENT_NODE);

  RefPtr<HTMLImageElement> img = new HTMLImageElement(nodeInfo);

  if (aWidth.WasPassed()) {
    img->SetWidth(aWidth.Value(), aError);
    if (aError.Failed()) {
      return nullptr;
    }

    if (aHeight.WasPassed()) {
      img->SetHeight(aHeight.Value(), aError);
      if (aError.Failed()) {
        return nullptr;
      }
    }
  }

  return img.forget();
}

uint32_t
HTMLImageElement::NaturalHeight()
{
  uint32_t height;
  nsresult rv = nsImageLoadingContent::GetNaturalHeight(&height);

  if (NS_FAILED(rv)) {
    MOZ_ASSERT(false, "GetNaturalHeight should not fail");
    return 0;
  }

  if (mResponsiveSelector) {
    double density = mResponsiveSelector->GetSelectedImageDensity();
    MOZ_ASSERT(density >= 0.0);
    height = NSToIntRound(double(height) / density);
    height = std::max(height, 0u);
  }

  return height;
}

NS_IMETHODIMP
HTMLImageElement::GetNaturalHeight(uint32_t* aNaturalHeight)
{
  *aNaturalHeight = NaturalHeight();
  return NS_OK;
}

uint32_t
HTMLImageElement::NaturalWidth()
{
  uint32_t width;
  nsresult rv = nsImageLoadingContent::GetNaturalWidth(&width);

  if (NS_FAILED(rv)) {
    MOZ_ASSERT(false, "GetNaturalWidth should not fail");
    return 0;
  }

  if (mResponsiveSelector) {
    double density = mResponsiveSelector->GetSelectedImageDensity();
    MOZ_ASSERT(density >= 0.0);
    width = NSToIntRound(double(width) / density);
    width = std::max(width, 0u);
  }

  return width;
}

NS_IMETHODIMP
HTMLImageElement::GetNaturalWidth(uint32_t* aNaturalWidth)
{
  *aNaturalWidth = NaturalWidth();
  return NS_OK;
}

nsresult
HTMLImageElement::CopyInnerTo(Element* aDest)
{
  bool destIsStatic = aDest->OwnerDoc()->IsStaticDocument();
  auto dest = static_cast<HTMLImageElement*>(aDest);
  if (destIsStatic) {
    CreateStaticImageClone(dest);
  }

  nsresult rv = nsGenericHTMLElement::CopyInnerTo(aDest);
  if (NS_FAILED(rv)) {
    return rv;
  }

  if (!destIsStatic) {
    // In SetAttr (called from nsGenericHTMLElement::CopyInnerTo), dest skipped
    // doing the image load because we passed in false for aNotify.  But we
    // really do want it to do the load, so set it up to happen once the cloning
    // reaches a stable state.
    if (!dest->InResponsiveMode() &&
        dest->HasAttr(kNameSpaceID_None, nsGkAtoms::src)) {
      nsContentUtils::AddScriptRunner(
        NewRunnableMethod(dest, &HTMLImageElement::MaybeLoadImage));
    }
  }

  return NS_OK;
}

CORSMode
HTMLImageElement::GetCORSMode()
{
  return AttrValueToCORSMode(GetParsedAttr(nsGkAtoms::crossorigin));
}

JSObject*
HTMLImageElement::WrapNode(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
{
  return HTMLImageElementBinding::Wrap(aCx, this, aGivenProto);
}

#ifdef DEBUG
nsIDOMHTMLFormElement*
HTMLImageElement::GetForm() const
{
  return mForm;
}
#endif

void
HTMLImageElement::SetForm(nsIDOMHTMLFormElement* aForm)
{
  NS_PRECONDITION(aForm, "Don't pass null here");
  NS_ASSERTION(!mForm,
               "We don't support switching from one non-null form to another.");

  mForm = static_cast<HTMLFormElement*>(aForm);
}

void
HTMLImageElement::ClearForm(bool aRemoveFromForm)
{
  NS_ASSERTION((mForm != nullptr) == HasFlag(ADDED_TO_FORM),
               "Form control should have had flag set correctly");

  if (!mForm) {
    return;
  }

  if (aRemoveFromForm) {
    nsAutoString nameVal, idVal;
    GetAttr(kNameSpaceID_None, nsGkAtoms::name, nameVal);
    GetAttr(kNameSpaceID_None, nsGkAtoms::id, idVal);

    mForm->RemoveImageElement(this);

    if (!nameVal.IsEmpty()) {
      mForm->RemoveImageElementFromTable(this, nameVal,
                                         HTMLFormElement::ElementRemoved);
    }

    if (!idVal.IsEmpty()) {
      mForm->RemoveImageElementFromTable(this, idVal,
                                         HTMLFormElement::ElementRemoved);
    }
  }

  UnsetFlags(ADDED_TO_FORM);
  mForm = nullptr;
}

void
HTMLImageElement::QueueImageLoadTask(bool aAlwaysLoad)
{
  // If loading is temporarily disabled, we don't want to queue tasks
  // that may then run when loading is re-enabled.
  if (!LoadingEnabled() || !this->OwnerDoc()->IsCurrentActiveDocument()) {
    return;
  }

  // Ensure that we don't overwrite a previous load request that requires
  // a complete load to occur.
  bool alwaysLoad = aAlwaysLoad;
  if (mPendingImageLoadTask) {
    alwaysLoad = alwaysLoad || mPendingImageLoadTask->AlwaysLoad();
  }
  RefPtr<ImageLoadTask> task = new ImageLoadTask(this, alwaysLoad);
  // The task checks this to determine if it was the last
  // queued event, and so earlier tasks are implicitly canceled.
  mPendingImageLoadTask = task;
  nsContentUtils::RunInStableState(task.forget());
}

bool
HTMLImageElement::HaveSrcsetOrInPicture()
{
  if (HasAttr(kNameSpaceID_None, nsGkAtoms::srcset)) {
    return true;
  }

  Element *parent = nsINode::GetParentElement();
  return (parent && parent->IsHTMLElement(nsGkAtoms::picture));
}

bool
HTMLImageElement::InResponsiveMode()
{
  // When we lose srcset or leave a <picture> element, the fallback to img.src
  // will happen from the microtask, and we should behave responsively in the
  // interim
  return mResponsiveSelector ||
         mPendingImageLoadTask ||
         HaveSrcsetOrInPicture();
}

bool
HTMLImageElement::SelectedSourceMatchesLast(nsIURI* aSelectedSource, double aSelectedDensity)
{
  // If there was no selected source previously, we don't want to short-circuit the load.
  // Similarly for if there is no newly selected source.
  if (!mLastSelectedSource || !aSelectedSource) {
    return false;
  }
  bool equal = false;
  return NS_SUCCEEDED(mLastSelectedSource->Equals(aSelectedSource, &equal)) && equal &&
      aSelectedDensity == mCurrentDensity;
}

nsresult
HTMLImageElement::LoadSelectedImage(bool aForce, bool aNotify, bool aAlwaysLoad)
{
  nsresult rv = NS_ERROR_FAILURE;

  if (aForce) {
    // In responsive mode we generally want to re-run the full
    // selection algorithm whenever starting a new load, per
    // spec. This also causes us to re-resolve the URI as appropriate.
    if (!UpdateResponsiveSource() && !aAlwaysLoad) {
      return NS_OK;
    }
  }

  nsCOMPtr<nsIURI> selectedSource;
  double currentDensity = 1.0; // default to 1.0 for the src attribute case
  if (mResponsiveSelector) {
    nsCOMPtr<nsIURI> url = mResponsiveSelector->GetSelectedImageURL();
    selectedSource = url;
    currentDensity = mResponsiveSelector->GetSelectedImageDensity();
    if (!aAlwaysLoad && SelectedSourceMatchesLast(selectedSource, currentDensity)) {
      return NS_OK;
    }
    if (url) {
      rv = LoadImage(url, aForce, aNotify, eImageLoadType_Imageset);
    }
  } else {
    nsAutoString src;
    if (!GetAttr(kNameSpaceID_None, nsGkAtoms::src, src)) {
      CancelImageRequests(aNotify);
      rv = NS_OK;
    } else {
      nsIDocument* doc = GetOurOwnerDoc();
      if (doc) {
        StringToURI(src, doc, getter_AddRefs(selectedSource));
        if (!aAlwaysLoad && SelectedSourceMatchesLast(selectedSource, currentDensity)) {
          return NS_OK;
        }
      }

      // If we have a srcset attribute or are in a <picture> element,
      // we always use the Imageset load type, even if we parsed no
      // valid responsive sources from either, per spec.
      rv = LoadImage(src, aForce, aNotify,
                     HaveSrcsetOrInPicture() ? eImageLoadType_Imageset
                                             : eImageLoadType_Normal);
    }
  }
  mLastSelectedSource = selectedSource;
  mCurrentDensity = currentDensity;

  if (NS_FAILED(rv)) {
    CancelImageRequests(aNotify);
  }
  return rv;
}

void
HTMLImageElement::PictureSourceSrcsetChanged(nsIContent *aSourceNode,
                                             const nsAString& aNewValue,
                                             bool aNotify)
{
  MOZ_ASSERT(aSourceNode == this ||
             IsPreviousSibling(aSourceNode, this),
             "Should not be getting notifications for non-previous-siblings");

  nsIContent *currentSrc =
    mResponsiveSelector ? mResponsiveSelector->Content() : nullptr;

  if (aSourceNode == currentSrc) {
    // We're currently using this node as our responsive selector
    // source.
    mResponsiveSelector->SetCandidatesFromSourceSet(aNewValue);
  }

  if (!mInDocResponsiveContent && IsInComposedDoc()) {
    nsIDocument* doc = GetOurOwnerDoc();
    if (doc) {
      doc->AddResponsiveContent(this);
      mInDocResponsiveContent = true;
    }
  }

  // This always triggers the image update steps per the spec, even if
  // we are not using this source.
  QueueImageLoadTask(true);
}

void
HTMLImageElement::PictureSourceSizesChanged(nsIContent *aSourceNode,
                                            const nsAString& aNewValue,
                                            bool aNotify)
{
  MOZ_ASSERT(aSourceNode == this ||
             IsPreviousSibling(aSourceNode, this),
             "Should not be getting notifications for non-previous-siblings");

  nsIContent *currentSrc =
    mResponsiveSelector ? mResponsiveSelector->Content() : nullptr;

  if (aSourceNode == currentSrc) {
    // We're currently using this node as our responsive selector
    // source.
    mResponsiveSelector->SetSizesFromDescriptor(aNewValue);
  }

  // This always triggers the image update steps per the spec, even if
  // we are not using this source.
  QueueImageLoadTask(true);
}

void
HTMLImageElement::PictureSourceMediaOrTypeChanged(nsIContent *aSourceNode,
                                                  bool aNotify)
{
  MOZ_ASSERT(IsPreviousSibling(aSourceNode, this),
             "Should not be getting notifications for non-previous-siblings");

  // This always triggers the image update steps per the spec, even if
  // we are not switching to/from this source
  QueueImageLoadTask(true);
}

void
HTMLImageElement::PictureSourceAdded(nsIContent *aSourceNode)
{
  MOZ_ASSERT(aSourceNode == this ||
             IsPreviousSibling(aSourceNode, this),
             "Should not be getting notifications for non-previous-siblings");

  QueueImageLoadTask(true);
}

void
HTMLImageElement::PictureSourceRemoved(nsIContent *aSourceNode)
{
  MOZ_ASSERT(aSourceNode == this ||
             IsPreviousSibling(aSourceNode, this),
             "Should not be getting notifications for non-previous-siblings");

  QueueImageLoadTask(true);
}

bool
HTMLImageElement::UpdateResponsiveSource()
{
  bool hadSelector = !!mResponsiveSelector;

  nsIContent *currentSource =
    mResponsiveSelector ? mResponsiveSelector->Content() : nullptr;
  Element *parent = nsINode::GetParentElement();

  nsINode *candidateSource = nullptr;
  if (parent && parent->IsHTMLElement(nsGkAtoms::picture)) {
    // Walk source nodes previous to ourselves
    candidateSource = parent->GetFirstChild();
  } else {
    candidateSource = this;
  }

  while (candidateSource) {
    if (candidateSource == currentSource) {
      // found no better source before current, re-run selection on
      // that and keep it if it's still usable.
      bool changed = mResponsiveSelector->SelectImage(true);
      if (mResponsiveSelector->NumCandidates()) {
        bool isUsableCandidate = true;

        // an otherwise-usable source element may still have a media query that may not
        // match any more.
        if (candidateSource->IsHTMLElement(nsGkAtoms::source) &&
            !SourceElementMatches(candidateSource->AsContent())) {
          isUsableCandidate = false;
        }

        if (isUsableCandidate) {
          return changed;
        }
      }

      // no longer valid
      mResponsiveSelector = nullptr;
      if (candidateSource == this) {
        // No further possibilities
        break;
      }
    } else if (candidateSource == this) {
      // We are the last possible source
      if (!TryCreateResponsiveSelector(candidateSource->AsContent())) {
        // Failed to find any source
        mResponsiveSelector = nullptr;
      }
      break;
    } else if (candidateSource->IsHTMLElement(nsGkAtoms::source) &&
               TryCreateResponsiveSelector(candidateSource->AsContent())) {
      // This led to a valid source, stop
      break;
    }
    candidateSource = candidateSource->GetNextSibling();
  }

  if (!candidateSource) {
    // Ran out of siblings without finding ourself, e.g. XBL magic.
    mResponsiveSelector = nullptr;
  }

  // If we reach this point, either:
  // - there was no selector originally, and there is not one now
  // - there was no selector originally, and there is one now
  // - there was a selector, and there is a different one now
  // - there was a selector, and there is not one now
  return hadSelector || mResponsiveSelector;
}

/*static */ bool
HTMLImageElement::SupportedPictureSourceType(const nsAString& aType)
{
  nsAutoString type;
  nsAutoString params;

  nsContentUtils::SplitMimeType(aType, type, params);
  if (type.IsEmpty()) {
    return true;
  }

  return
    imgLoader::SupportImageWithMimeType(NS_ConvertUTF16toUTF8(type).get(),
                                        AcceptedMimeTypes::IMAGES_AND_DOCUMENTS);
}

bool
HTMLImageElement::SourceElementMatches(nsIContent* aSourceNode)
{
  MOZ_ASSERT(aSourceNode->IsHTMLElement(nsGkAtoms::source));

  DebugOnly<Element *> parent(nsINode::GetParentElement());
  MOZ_ASSERT(parent && parent->IsHTMLElement(nsGkAtoms::picture));
  MOZ_ASSERT(IsPreviousSibling(aSourceNode, this));

  // Check media and type
  HTMLSourceElement *src = static_cast<HTMLSourceElement*>(aSourceNode);
  if (!src->MatchesCurrentMedia()) {
    return false;
  }

  nsAutoString type;
  if (aSourceNode->GetAttr(kNameSpaceID_None, nsGkAtoms::type, type) &&
      !SupportedPictureSourceType(type)) {
    return false;
  }

  return true;
}

bool
HTMLImageElement::TryCreateResponsiveSelector(nsIContent *aSourceNode)
{
  // Skip if this is not a <source> with matching media query
  bool isSourceTag = aSourceNode->IsHTMLElement(nsGkAtoms::source);
  if (isSourceTag) {
    if (!SourceElementMatches(aSourceNode)) {
      return false;
    }
  } else if (aSourceNode->IsHTMLElement(nsGkAtoms::img)) {
    // Otherwise this is the <img> tag itself
    MOZ_ASSERT(aSourceNode == this);
  }

  // Skip if has no srcset or an empty srcset
  nsString srcset;
  if (!aSourceNode->GetAttr(kNameSpaceID_None, nsGkAtoms::srcset, srcset)) {
    return false;
  }

  if (srcset.IsEmpty()) {
    return false;
  }


  // Try to parse
  RefPtr<ResponsiveImageSelector> sel = new ResponsiveImageSelector(aSourceNode);
  if (!sel->SetCandidatesFromSourceSet(srcset)) {
    // No possible candidates, don't need to bother parsing sizes
    return false;
  }

  nsAutoString sizes;
  aSourceNode->GetAttr(kNameSpaceID_None, nsGkAtoms::sizes, sizes);
  sel->SetSizesFromDescriptor(sizes);

  // If this is the <img> tag, also pull in src as the default source
  if (!isSourceTag) {
    MOZ_ASSERT(aSourceNode == this);
    nsAutoString src;
    if (GetAttr(kNameSpaceID_None, nsGkAtoms::src, src) && !src.IsEmpty()) {
      sel->SetDefaultSource(src);
    }
  }

  mResponsiveSelector = sel;
  return true;
}

/* static */ bool
HTMLImageElement::SelectSourceForTagWithAttrs(nsIDocument *aDocument,
                                              bool aIsSourceTag,
                                              const nsAString& aSrcAttr,
                                              const nsAString& aSrcsetAttr,
                                              const nsAString& aSizesAttr,
                                              const nsAString& aTypeAttr,
                                              const nsAString& aMediaAttr,
                                              nsAString& aResult)
{
  MOZ_ASSERT(aIsSourceTag || (aTypeAttr.IsEmpty() && aMediaAttr.IsEmpty()),
             "Passing type or media attrs makes no sense without aIsSourceTag");
  MOZ_ASSERT(!aIsSourceTag || aSrcAttr.IsEmpty(),
             "Passing aSrcAttr makes no sense with aIsSourceTag set");

  if (aSrcsetAttr.IsEmpty()) {
    if (!aIsSourceTag) {
      // For an <img> with no srcset, we would always select the src attr.
      aResult.Assign(aSrcAttr);
      return true;
    }
    // Otherwise, a <source> without srcset is never selected
    return false;
  }

  // Would not consider source tags with unsupported media or type
  if (aIsSourceTag &&
      ((!aMediaAttr.IsVoid() &&
       !HTMLSourceElement::WouldMatchMediaForDocument(aMediaAttr, aDocument)) ||
      (!aTypeAttr.IsVoid() &&
       !SupportedPictureSourceType(aTypeAttr)))) {
    return false;
  }

  // Using srcset or picture <source>, build a responsive selector for this tag.
  RefPtr<ResponsiveImageSelector> sel =
    new ResponsiveImageSelector(aDocument);

  sel->SetCandidatesFromSourceSet(aSrcsetAttr);
  if (!aSizesAttr.IsEmpty()) {
    sel->SetSizesFromDescriptor(aSizesAttr);
  }
  if (!aIsSourceTag) {
    sel->SetDefaultSource(aSrcAttr);
  }

  if (sel->GetSelectedImageURLSpec(aResult)) {
    return true;
  }

  if (!aIsSourceTag) {
    // <img> tag with no match would definitively load nothing.
    aResult.Truncate();
    return true;
  }

  // <source> tags with no match would leave source yet-undetermined.
  return false;
}

void
HTMLImageElement::DestroyContent()
{
  mResponsiveSelector = nullptr;

  nsGenericHTMLElement::DestroyContent();
}

void
HTMLImageElement::MediaFeatureValuesChanged()
{
  QueueImageLoadTask(false);
}

void
HTMLImageElement::FlushUseCounters()
{
  nsCOMPtr<imgIRequest> request;
  GetRequest(CURRENT_REQUEST, getter_AddRefs(request));

  nsCOMPtr<imgIContainer> container;
  request->GetImage(getter_AddRefs(container));

  static_cast<image::Image*>(container.get())->ReportUseCounters();
}

} // namespace dom
} // namespace mozilla