gecko-dev/dom/html/ImageDocument.cpp

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22 KiB
C++

/* -*- 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 "ImageDocument.h"
#include "mozilla/AutoRestore.h"
#include "mozilla/ComputedStyle.h"
#include "mozilla/dom/Element.h"
#include "mozilla/dom/Event.h"
#include "mozilla/dom/ImageDocumentBinding.h"
#include "mozilla/dom/HTMLImageElement.h"
#include "mozilla/dom/MouseEvent.h"
#include "mozilla/LoadInfo.h"
#include "mozilla/PresShell.h"
#include "mozilla/StaticPrefs_browser.h"
#include "mozilla/StaticPrefs_privacy.h"
#include "nsRect.h"
#include "nsIImageLoadingContent.h"
#include "nsGenericHTMLElement.h"
#include "nsDocShell.h"
#include "DocumentInlines.h"
#include "nsDOMTokenList.h"
#include "nsIDOMEventListener.h"
#include "nsIFrame.h"
#include "nsGkAtoms.h"
#include "imgIRequest.h"
#include "imgIContainer.h"
#include "imgINotificationObserver.h"
#include "nsPresContext.h"
#include "nsIChannel.h"
#include "nsIContentPolicy.h"
#include "nsContentPolicyUtils.h"
#include "nsPIDOMWindow.h"
#include "nsError.h"
#include "nsURILoader.h"
#include "nsIDocShell.h"
#include "nsIContentViewer.h"
#include "nsThreadUtils.h"
#include "nsIScrollableFrame.h"
#include "nsContentUtils.h"
#include "mozilla/Preferences.h"
#include <algorithm>
// XXX A hack needed for Firefox's site specific zoom.
static bool IsSiteSpecific() {
return !mozilla::StaticPrefs::privacy_resistFingerprinting() &&
mozilla::Preferences::GetBool("browser.zoom.siteSpecific", false);
}
namespace mozilla::dom {
class ImageListener : public MediaDocumentStreamListener {
public:
// NS_DECL_NSIREQUESTOBSERVER
// We only implement OnStartRequest; OnStopRequest is
// implemented by MediaDocumentStreamListener
NS_IMETHOD OnStartRequest(nsIRequest* aRequest) override;
explicit ImageListener(ImageDocument* aDocument);
virtual ~ImageListener();
};
ImageListener::ImageListener(ImageDocument* aDocument)
: MediaDocumentStreamListener(aDocument) {}
ImageListener::~ImageListener() = default;
NS_IMETHODIMP
ImageListener::OnStartRequest(nsIRequest* request) {
NS_ENSURE_TRUE(mDocument, NS_ERROR_FAILURE);
ImageDocument* imgDoc = static_cast<ImageDocument*>(mDocument.get());
nsCOMPtr<nsIChannel> channel = do_QueryInterface(request);
if (!channel) {
return NS_ERROR_FAILURE;
}
nsCOMPtr<nsPIDOMWindowOuter> domWindow = imgDoc->GetWindow();
NS_ENSURE_TRUE(domWindow, NS_ERROR_UNEXPECTED);
// Do a ShouldProcess check to see whether to keep loading the image.
nsCOMPtr<nsIURI> channelURI;
channel->GetURI(getter_AddRefs(channelURI));
nsAutoCString mimeType;
channel->GetContentType(mimeType);
nsCOMPtr<nsILoadInfo> loadInfo = channel->LoadInfo();
// query the corresponding arguments for the channel loadinfo and pass
// it on to the temporary loadinfo used for content policy checks.
nsCOMPtr<nsINode> requestingNode = domWindow->GetFrameElementInternal();
nsCOMPtr<nsIPrincipal> loadingPrincipal;
if (requestingNode) {
loadingPrincipal = requestingNode->NodePrincipal();
} else {
nsContentUtils::GetSecurityManager()->GetChannelResultPrincipal(
channel, getter_AddRefs(loadingPrincipal));
}
nsCOMPtr<nsILoadInfo> secCheckLoadInfo = new net::LoadInfo(
loadingPrincipal, loadInfo->TriggeringPrincipal(), requestingNode,
nsILoadInfo::SEC_ONLY_FOR_EXPLICIT_CONTENTSEC_CHECK,
nsIContentPolicy::TYPE_INTERNAL_IMAGE);
int16_t decision = nsIContentPolicy::ACCEPT;
nsresult rv = NS_CheckContentProcessPolicy(
channelURI, secCheckLoadInfo, mimeType, &decision,
nsContentUtils::GetContentPolicy());
if (NS_FAILED(rv) || NS_CP_REJECTED(decision)) {
request->Cancel(NS_ERROR_CONTENT_BLOCKED);
return NS_OK;
}
if (!imgDoc->mObservingImageLoader) {
NS_ENSURE_TRUE(imgDoc->mImageContent, NS_ERROR_UNEXPECTED);
imgDoc->mImageContent->AddNativeObserver(imgDoc);
imgDoc->mObservingImageLoader = true;
imgDoc->mImageContent->LoadImageWithChannel(channel,
getter_AddRefs(mNextStream));
}
return MediaDocumentStreamListener::OnStartRequest(request);
}
ImageDocument::ImageDocument()
: MediaDocument(),
mVisibleWidth(0.0),
mVisibleHeight(0.0),
mImageWidth(0),
mImageHeight(0),
mImageIsResized(false),
mShouldResize(false),
mFirstResize(false),
mObservingImageLoader(false),
mTitleUpdateInProgress(false),
mHasCustomTitle(false),
mOriginalZoomLevel(1.0),
mOriginalResolution(1.0) {}
ImageDocument::~ImageDocument() = default;
NS_IMPL_CYCLE_COLLECTION_INHERITED(ImageDocument, MediaDocument, mImageContent)
NS_IMPL_ISUPPORTS_CYCLE_COLLECTION_INHERITED(ImageDocument, MediaDocument,
imgINotificationObserver,
nsIDOMEventListener)
nsresult ImageDocument::Init() {
nsresult rv = MediaDocument::Init();
NS_ENSURE_SUCCESS(rv, rv);
mShouldResize = StaticPrefs::browser_enable_automatic_image_resizing();
mFirstResize = true;
return NS_OK;
}
JSObject* ImageDocument::WrapNode(JSContext* aCx,
JS::Handle<JSObject*> aGivenProto) {
return ImageDocument_Binding::Wrap(aCx, this, aGivenProto);
}
nsresult ImageDocument::StartDocumentLoad(const char* aCommand,
nsIChannel* aChannel,
nsILoadGroup* aLoadGroup,
nsISupports* aContainer,
nsIStreamListener** aDocListener,
bool aReset, nsIContentSink* aSink) {
nsresult rv = MediaDocument::StartDocumentLoad(
aCommand, aChannel, aLoadGroup, aContainer, aDocListener, aReset, aSink);
if (NS_FAILED(rv)) {
return rv;
}
mOriginalZoomLevel = IsSiteSpecific() ? 1.0 : GetZoomLevel();
mOriginalResolution = GetResolution();
NS_ASSERTION(aDocListener, "null aDocListener");
*aDocListener = new ImageListener(this);
NS_ADDREF(*aDocListener);
return NS_OK;
}
void ImageDocument::Destroy() {
if (RefPtr<HTMLImageElement> img = std::move(mImageContent)) {
// Remove our event listener from the image content.
img->RemoveEventListener(u"load"_ns, this, false);
img->RemoveEventListener(u"click"_ns, this, false);
// Break reference cycle with mImageContent, if we have one
if (mObservingImageLoader) {
img->RemoveNativeObserver(this);
}
}
MediaDocument::Destroy();
}
void ImageDocument::SetScriptGlobalObject(
nsIScriptGlobalObject* aScriptGlobalObject) {
// If the script global object is changing, we need to unhook our event
// listeners on the window.
nsCOMPtr<EventTarget> target;
if (mScriptGlobalObject && aScriptGlobalObject != mScriptGlobalObject) {
target = do_QueryInterface(mScriptGlobalObject);
target->RemoveEventListener(u"resize"_ns, this, false);
target->RemoveEventListener(u"keypress"_ns, this, false);
}
// Set the script global object on the superclass before doing
// anything that might require it....
MediaDocument::SetScriptGlobalObject(aScriptGlobalObject);
if (aScriptGlobalObject) {
if (!InitialSetupHasBeenDone()) {
MOZ_ASSERT(!GetRootElement(), "Where did the root element come from?");
// Create synthetic document
#ifdef DEBUG
nsresult rv =
#endif
CreateSyntheticDocument();
NS_ASSERTION(NS_SUCCEEDED(rv), "failed to create synthetic document");
target = mImageContent;
target->AddEventListener(u"load"_ns, this, false);
target->AddEventListener(u"click"_ns, this, false);
}
target = do_QueryInterface(aScriptGlobalObject);
target->AddEventListener(u"resize"_ns, this, false);
target->AddEventListener(u"keypress"_ns, this, false);
if (!InitialSetupHasBeenDone()) {
LinkStylesheet(u"resource://content-accessible/ImageDocument.css"_ns);
if (!nsContentUtils::IsChildOfSameType(this)) {
LinkStylesheet(nsLiteralString(
u"resource://content-accessible/TopLevelImageDocument.css"));
LinkStylesheet(nsLiteralString(
u"chrome://global/skin/media/TopLevelImageDocument.css"));
}
InitialSetupDone();
}
}
}
void ImageDocument::OnPageShow(bool aPersisted,
EventTarget* aDispatchStartTarget,
bool aOnlySystemGroup) {
if (aPersisted) {
mOriginalZoomLevel = IsSiteSpecific() ? 1.0 : GetZoomLevel();
mOriginalResolution = GetResolution();
}
RefPtr<ImageDocument> kungFuDeathGrip(this);
UpdateSizeFromLayout();
MediaDocument::OnPageShow(aPersisted, aDispatchStartTarget, aOnlySystemGroup);
}
void ImageDocument::ShrinkToFit() {
if (!mImageContent) {
return;
}
if (GetZoomLevel() != mOriginalZoomLevel && mImageIsResized &&
!nsContentUtils::IsChildOfSameType(this)) {
// If we're zoomed, so that we don't maintain the invariant that
// mImageIsResized if and only if its displayed width/height fit in
// mVisibleWidth/mVisibleHeight, then we may need to switch to/from the
// overflowingVertical class here, because our viewport size may have
// changed and we don't plan to adjust the image size to compensate. Since
// mImageIsResized it has a "height" attribute set, and we can just get the
// displayed image height by getting .height on the HTMLImageElement.
//
// Hold strong ref, because Height() can run script.
RefPtr<HTMLImageElement> img = mImageContent;
uint32_t imageHeight = img->Height();
nsDOMTokenList* classList = img->ClassList();
if (imageHeight > mVisibleHeight) {
classList->Add(u"overflowingVertical"_ns, IgnoreErrors());
} else {
classList->Remove(u"overflowingVertical"_ns, IgnoreErrors());
}
return;
}
if (GetResolution() != mOriginalResolution && mImageIsResized) {
// Don't resize if resolution has changed, e.g., through pinch-zooming on
// Android.
return;
}
// Keep image content alive while changing the attributes.
RefPtr<HTMLImageElement> image = mImageContent;
uint32_t newWidth = std::max(1, NSToCoordFloor(GetRatio() * mImageWidth));
uint32_t newHeight = std::max(1, NSToCoordFloor(GetRatio() * mImageHeight));
image->SetWidth(newWidth, IgnoreErrors());
image->SetHeight(newHeight, IgnoreErrors());
// The view might have been scrolled when zooming in, scroll back to the
// origin now that we're showing a shrunk-to-window version.
ScrollImageTo(0, 0);
if (!mImageContent) {
// ScrollImageTo flush destroyed our content.
return;
}
SetModeClass(eShrinkToFit);
mImageIsResized = true;
UpdateTitleAndCharset();
}
void ImageDocument::ScrollImageTo(int32_t aX, int32_t aY) {
RefPtr<PresShell> presShell = GetPresShell();
if (!presShell) {
return;
}
nsIScrollableFrame* sf = presShell->GetRootScrollFrameAsScrollable();
if (!sf) {
return;
}
float ratio = GetRatio();
// Don't try to scroll image if the document is not visible (mVisibleWidth or
// mVisibleHeight is zero).
if (ratio <= 0.0) {
return;
}
nsRect portRect = sf->GetScrollPortRect();
sf->ScrollTo(
nsPoint(
nsPresContext::CSSPixelsToAppUnits(aX / ratio) - portRect.width / 2,
nsPresContext::CSSPixelsToAppUnits(aY / ratio) - portRect.height / 2),
ScrollMode::Instant);
}
void ImageDocument::RestoreImage() {
if (!mImageContent) {
return;
}
// Keep image content alive while changing the attributes.
RefPtr<HTMLImageElement> imageContent = mImageContent;
imageContent->UnsetAttr(kNameSpaceID_None, nsGkAtoms::width, true);
imageContent->UnsetAttr(kNameSpaceID_None, nsGkAtoms::height, true);
if (ImageIsOverflowing()) {
if (!ImageIsOverflowingVertically()) {
SetModeClass(eOverflowingHorizontalOnly);
} else {
SetModeClass(eOverflowingVertical);
}
} else {
SetModeClass(eNone);
}
mImageIsResized = false;
UpdateTitleAndCharset();
}
void ImageDocument::NotifyPossibleTitleChange(bool aBoundTitleElement) {
if (!mHasCustomTitle && !mTitleUpdateInProgress) {
mHasCustomTitle = true;
}
Document::NotifyPossibleTitleChange(aBoundTitleElement);
}
void ImageDocument::Notify(imgIRequest* aRequest, int32_t aType,
const nsIntRect* aData) {
if (aType == imgINotificationObserver::SIZE_AVAILABLE) {
nsCOMPtr<imgIContainer> image;
aRequest->GetImage(getter_AddRefs(image));
return OnSizeAvailable(aRequest, image);
}
// Run this using a script runner because HAS_TRANSPARENCY notifications can
// come during painting and this will trigger invalidation.
if (aType == imgINotificationObserver::HAS_TRANSPARENCY) {
nsCOMPtr<nsIRunnable> runnable =
NewRunnableMethod("dom::ImageDocument::OnHasTransparency", this,
&ImageDocument::OnHasTransparency);
nsContentUtils::AddScriptRunner(runnable);
}
if (aType == imgINotificationObserver::LOAD_COMPLETE) {
uint32_t reqStatus;
aRequest->GetImageStatus(&reqStatus);
nsresult status =
reqStatus & imgIRequest::STATUS_ERROR ? NS_ERROR_FAILURE : NS_OK;
return OnLoadComplete(aRequest, status);
}
}
void ImageDocument::OnHasTransparency() {
if (!mImageContent || nsContentUtils::IsChildOfSameType(this)) {
return;
}
nsDOMTokenList* classList = mImageContent->ClassList();
classList->Add(u"transparent"_ns, IgnoreErrors());
}
void ImageDocument::SetModeClass(eModeClasses mode) {
nsDOMTokenList* classList = mImageContent->ClassList();
if (mode == eShrinkToFit) {
classList->Add(u"shrinkToFit"_ns, IgnoreErrors());
} else {
classList->Remove(u"shrinkToFit"_ns, IgnoreErrors());
}
if (mode == eOverflowingVertical) {
classList->Add(u"overflowingVertical"_ns, IgnoreErrors());
} else {
classList->Remove(u"overflowingVertical"_ns, IgnoreErrors());
}
if (mode == eOverflowingHorizontalOnly) {
classList->Add(u"overflowingHorizontalOnly"_ns, IgnoreErrors());
} else {
classList->Remove(u"overflowingHorizontalOnly"_ns, IgnoreErrors());
}
}
void ImageDocument::OnSizeAvailable(imgIRequest* aRequest,
imgIContainer* aImage) {
int32_t oldWidth = mImageWidth;
int32_t oldHeight = mImageHeight;
// Styles have not yet been applied, so we don't know the final size. For now,
// default to the image's intrinsic size.
aImage->GetWidth(&mImageWidth);
aImage->GetHeight(&mImageHeight);
// Multipart images send size available for each part; ignore them if it
// doesn't change our size. (We may not even support changing size in
// multipart images in the future.)
if (oldWidth == mImageWidth && oldHeight == mImageHeight) {
return;
}
nsCOMPtr<nsIRunnable> runnable =
NewRunnableMethod("dom::ImageDocument::DefaultCheckOverflowing", this,
&ImageDocument::DefaultCheckOverflowing);
nsContentUtils::AddScriptRunner(runnable);
UpdateTitleAndCharset();
}
void ImageDocument::OnLoadComplete(imgIRequest* aRequest, nsresult aStatus) {
UpdateTitleAndCharset();
// mImageContent can be null if the document is already destroyed
if (NS_FAILED(aStatus) && mImageContent) {
nsAutoCString src;
mDocumentURI->GetSpec(src);
AutoTArray<nsString, 1> formatString;
CopyUTF8toUTF16(src, *formatString.AppendElement());
nsAutoString errorMsg;
FormatStringFromName("InvalidImage", formatString, errorMsg);
mImageContent->SetAttr(kNameSpaceID_None, nsGkAtoms::alt, errorMsg, false);
}
}
NS_IMETHODIMP
ImageDocument::HandleEvent(Event* aEvent) {
nsAutoString eventType;
aEvent->GetType(eventType);
if (eventType.EqualsLiteral("resize")) {
CheckOverflowing(false);
} else if (eventType.EqualsLiteral("click") &&
StaticPrefs::browser_enable_click_image_resizing()) {
ResetZoomLevel();
mShouldResize = true;
if (mImageIsResized) {
int32_t x = 0, y = 0;
MouseEvent* event = aEvent->AsMouseEvent();
if (event) {
RefPtr<HTMLImageElement> img = mImageContent;
x = event->ClientX() - img->OffsetLeft();
y = event->ClientY() - img->OffsetTop();
}
mShouldResize = false;
RestoreImage();
FlushPendingNotifications(FlushType::Layout);
ScrollImageTo(x, y);
} else if (ImageIsOverflowing()) {
ShrinkToFit();
}
} else if (eventType.EqualsLiteral("load")) {
UpdateSizeFromLayout();
}
return NS_OK;
}
void ImageDocument::UpdateSizeFromLayout() {
// Pull an updated size from the content frame to account for any size
// change due to CSS properties like |image-orientation|.
if (!mImageContent) {
return;
}
// Need strong ref, because GetPrimaryFrame can run script.
RefPtr<HTMLImageElement> imageContent = mImageContent;
nsIFrame* contentFrame = imageContent->GetPrimaryFrame(FlushType::Frames);
if (!contentFrame) {
return;
}
nsIntSize oldSize(mImageWidth, mImageHeight);
IntrinsicSize newSize = contentFrame->GetIntrinsicSize();
if (newSize.width) {
mImageWidth = nsPresContext::AppUnitsToFloatCSSPixels(*newSize.width);
}
if (newSize.height) {
mImageHeight = nsPresContext::AppUnitsToFloatCSSPixels(*newSize.height);
}
// Ensure that our information about overflow is up-to-date if needed.
if (mImageWidth != oldSize.width || mImageHeight != oldSize.height) {
CheckOverflowing(false);
}
}
nsresult ImageDocument::CreateSyntheticDocument() {
// Synthesize an html document that refers to the image
nsresult rv = MediaDocument::CreateSyntheticDocument();
NS_ENSURE_SUCCESS(rv, rv);
// Add the image element
RefPtr<Element> body = GetBodyElement();
if (!body) {
NS_WARNING("no body on image document!");
return NS_ERROR_FAILURE;
}
RefPtr<mozilla::dom::NodeInfo> nodeInfo;
nodeInfo = mNodeInfoManager->GetNodeInfo(
nsGkAtoms::img, nullptr, kNameSpaceID_XHTML, nsINode::ELEMENT_NODE);
RefPtr<Element> image = NS_NewHTMLImageElement(nodeInfo.forget());
mImageContent = HTMLImageElement::FromNodeOrNull(image);
if (!mImageContent) {
return NS_ERROR_OUT_OF_MEMORY;
}
nsAutoCString src;
mDocumentURI->GetSpec(src);
NS_ConvertUTF8toUTF16 srcString(src);
// Make sure not to start the image load from here...
mImageContent->SetLoadingEnabled(false);
mImageContent->SetAttr(kNameSpaceID_None, nsGkAtoms::src, srcString, false);
mImageContent->SetAttr(kNameSpaceID_None, nsGkAtoms::alt, srcString, false);
body->AppendChildTo(mImageContent, false, IgnoreErrors());
mImageContent->SetLoadingEnabled(true);
return NS_OK;
}
void ImageDocument::DefaultCheckOverflowing() {
CheckOverflowing(StaticPrefs::browser_enable_automatic_image_resizing());
}
nsresult ImageDocument::CheckOverflowing(bool changeState) {
const bool imageWasOverflowing = ImageIsOverflowing();
const bool imageWasOverflowingVertically = ImageIsOverflowingVertically();
{
nsPresContext* context = GetPresContext();
if (!context) {
return NS_OK;
}
nsRect visibleArea = context->GetVisibleArea();
mVisibleWidth = nsPresContext::AppUnitsToFloatCSSPixels(visibleArea.width);
mVisibleHeight =
nsPresContext::AppUnitsToFloatCSSPixels(visibleArea.height);
}
const bool windowBecameBigEnough =
imageWasOverflowing && !ImageIsOverflowing();
const bool verticalOverflowChanged =
imageWasOverflowingVertically != ImageIsOverflowingVertically();
if (changeState || mShouldResize || mFirstResize || windowBecameBigEnough ||
verticalOverflowChanged) {
if (ImageIsOverflowing() && (changeState || mShouldResize)) {
ShrinkToFit();
} else if (mImageIsResized || mFirstResize || windowBecameBigEnough) {
RestoreImage();
} else if (!mImageIsResized && verticalOverflowChanged) {
if (ImageIsOverflowingVertically()) {
SetModeClass(eOverflowingVertical);
} else {
SetModeClass(eOverflowingHorizontalOnly);
}
}
}
mFirstResize = false;
return NS_OK;
}
void ImageDocument::UpdateTitleAndCharset() {
if (mHasCustomTitle) {
return;
}
AutoRestore<bool> restore(mTitleUpdateInProgress);
mTitleUpdateInProgress = true;
nsAutoCString typeStr;
nsCOMPtr<imgIRequest> imageRequest;
if (mImageContent) {
mImageContent->GetRequest(nsIImageLoadingContent::CURRENT_REQUEST,
getter_AddRefs(imageRequest));
}
if (imageRequest) {
nsCString mimeType;
imageRequest->GetMimeType(getter_Copies(mimeType));
ToUpperCase(mimeType);
nsCString::const_iterator start, end;
mimeType.BeginReading(start);
mimeType.EndReading(end);
nsCString::const_iterator iter = end;
if (FindInReadable("IMAGE/"_ns, start, iter) && iter != end) {
// strip out "X-" if any
if (*iter == 'X') {
++iter;
if (iter != end && *iter == '-') {
++iter;
if (iter == end) {
// looks like "IMAGE/X-" is the type?? Bail out of here.
mimeType.BeginReading(iter);
}
} else {
--iter;
}
}
typeStr = Substring(iter, end);
} else {
typeStr = mimeType;
}
}
nsAutoString status;
if (mImageIsResized) {
AutoTArray<nsString, 1> formatString;
formatString.AppendElement()->AppendInt(NSToCoordFloor(GetRatio() * 100));
FormatStringFromName("ScaledImage", formatString, status);
}
static const char* const formatNames[4] = {
"ImageTitleWithNeitherDimensionsNorFile",
"ImageTitleWithoutDimensions",
"ImageTitleWithDimensions2",
"ImageTitleWithDimensions2AndFile",
};
MediaDocument::UpdateTitleAndCharset(typeStr, mChannel, formatNames,
mImageWidth, mImageHeight, status);
}
void ImageDocument::ResetZoomLevel() {
if (nsContentUtils::IsChildOfSameType(this)) {
return;
}
if (RefPtr<BrowsingContext> bc = GetBrowsingContext()) {
// Resetting the zoom level on a discarded browsing context has no effect.
Unused << bc->SetFullZoom(mOriginalZoomLevel);
}
}
float ImageDocument::GetZoomLevel() {
if (BrowsingContext* bc = GetBrowsingContext()) {
return bc->FullZoom();
}
return mOriginalZoomLevel;
}
float ImageDocument::GetResolution() {
if (PresShell* presShell = GetPresShell()) {
return presShell->GetResolution();
}
return mOriginalResolution;
}
} // namespace mozilla::dom
nsresult NS_NewImageDocument(mozilla::dom::Document** aResult) {
auto* doc = new mozilla::dom::ImageDocument();
NS_ADDREF(doc);
nsresult rv = doc->Init();
if (NS_FAILED(rv)) {
NS_RELEASE(doc);
}
*aResult = doc;
return rv;
}