gecko-dev/dom/html/HTMLImageElement.cpp
Emilio Cobos Álvarez f09824aad6 Bug 1149357: Properly update responsive images for density changes. r=dholbert
Before that we were not notifying the image frame in any way if we ended up not
doing a load, and we were instead relying on the reflow the viewport resize
caused to get the new density in ComputeSize from the content node (but nowhere
else, since that's the bug part 1 fixes).

This was generally unsound, since you can stash random media in a sizes=
attribute, which don't necessarily needs to cause a reflow.

Now we need to notify necessarily because nsImageFrame stores the adjusted
intrinsic size.

mCurrentDensity could also get out of sync as well, when the selected image
density changed, but we ended up returning early because our source hadn't
change in the first early exit.

This patch moves us to a model where we don't re-trigger loads for density
changes if the source doesn't change (unless we pass aAlwaysLoad when we need
to, per spec).

This matches our previous behavior (without the bugginess of not updating the
intrinsic size), and also Chromium, at least.

This changes behavior in one case, which is when we don't load the same source
node, but we have the same source URL, and the density does change. This could
happen with <picture> and two <source>s with same source and different media and
sizes. This makes our behavior consistent with the behavior we have when both
the source and the density doesn't change.

Blink and WebKit do trigger a second image load both when the source changes
without changing density and when density changes. I'll file a spec issue, since
per:

  https://html.spec.whatwg.org/#reacting-to-environment-changes

We should be triggering the load when the density changes but the source
doesn't as well, but no UA does that.

I filed https://github.com/whatwg/html/issues/3709 with a little summary of the
situation and what I think the behavior should be (which is what this patch
implements). That being said, I'll update the impl if the spec people think
otherwise :).

MozReview-Commit-ID: Eqy16ygHRLo
2018-05-25 12:09:30 +02:00

1394 lines
43 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 "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 "nsImageFrame.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 "mozilla/dom/MutationEventBinding.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 "mozilla/EventDispatcher.h"
#include "mozilla/EventStates.h"
#include "mozilla/GenericSpecifiedValuesInlines.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->ComputeIndexOf(aSubject) < parent->ComputeIndexOf(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,
bool aUseUrgentStartForChannel)
: Runnable("dom::ImageLoadTask")
, mElement(aElement)
, mAlwaysLoad(aAlwaysLoad)
, mUseUrgentStartForChannel(aUseUrgentStartForChannel)
{
mDocument = aElement->OwnerDoc();
mDocument->BlockOnload();
}
NS_IMETHOD Run() override
{
if (mElement->mPendingImageLoadTask == this) {
mElement->mPendingImageLoadTask = nullptr;
mElement->mUseUrgentStartForChannel = mUseUrgentStartForChannel;
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;
// True if we want to set nsIClassOfService::UrgentStart to the channel to
// get the response ASAP for better user responsiveness.
bool mUseUrgentStartForChannel;
};
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_CYCLE_COLLECTION_INHERITED(HTMLImageElement,
nsGenericHTMLElement,
mResponsiveSelector)
NS_IMPL_ISUPPORTS_CYCLE_COLLECTION_INHERITED(HTMLImageElement,
nsGenericHTMLElement,
nsIImageLoadingContent,
imgINotificationObserver)
NS_IMPL_ELEMENT_CLONE(HTMLImageElement)
bool
HTMLImageElement::IsInteractiveHTMLContent(bool aIgnoreTabindex) const
{
return HasAttr(kNameSpaceID_None, nsGkAtoms::usemap) ||
nsGenericHTMLElement::IsInteractiveHTMLContent(aIgnoreTabindex);
}
void
HTMLImageElement::AsyncEventRunning(AsyncEventDispatcher* aEvent)
{
nsImageLoadingContent::AsyncEventRunning(aEvent);
}
void
HTMLImageElement::GetCurrentSrc(nsAString& aValue)
{
nsCOMPtr<nsIURI> currentURI;
GetCurrentURI(getter_AddRefs(currentURI));
if (currentURI) {
nsAutoCString spec;
currentURI->GetSpec(spec);
CopyUTF8toUTF16(spec, aValue);
} else {
SetDOMStringToNull(aValue);
}
}
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;
}
CSSIntPoint
HTMLImageElement::GetXY()
{
nsIFrame* frame = GetPrimaryFrame(FlushType::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;
}
bool
HTMLImageElement::ParseAttribute(int32_t aNamespaceID,
nsAtom* aAttribute,
const nsAString& aValue,
nsIPrincipal* aMaybeScriptedPrincipal,
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,
aMaybeScriptedPrincipal, aResult);
}
void
HTMLImageElement::MapAttributesIntoRule(const nsMappedAttributes* aAttributes,
GenericSpecifiedValues* 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 nsAtom* 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 == MutationEventBinding::ADDITION ||
aModType == MutationEventBinding::REMOVAL) {
retval |= nsChangeHint_ReconstructFrame;
}
}
return retval;
}
NS_IMETHODIMP_(bool)
HTMLImageElement::IsAttributeMapped(const nsAtom* 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, nsAtom* aName,
const 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);
}
}
return nsGenericHTMLElement::BeforeSetAttr(aNameSpaceID, aName,
aValue, aNotify);
}
nsresult
HTMLImageElement::AfterSetAttr(int32_t aNameSpaceID, nsAtom* aName,
const nsAttrValue* aValue,
const nsAttrValue* aOldValue,
nsIPrincipal* aMaybeScriptedPrincipal,
bool aNotify)
{
nsAttrValueOrString attrVal(aValue);
if (aValue) {
AfterMaybeChangeAttr(aNameSpaceID, aName, attrVal, aOldValue,
aMaybeScriptedPrincipal, true, 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.
if (aName == nsGkAtoms::src &&
aNameSpaceID == kNameSpaceID_None &&
!aValue) {
// Mark channel as urgent-start before load image if the image load is
// initaiated by a user interaction.
mUseUrgentStartForChannel = EventStateManager::IsHandlingUserInput();
// 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(VoidString());
}
QueueImageLoadTask(true);
} else {
// Bug 1076583 - We still behave synchronously in the non-responsive case
CancelImageRequests(aNotify);
}
} else if (aName == nsGkAtoms::srcset &&
aNameSpaceID == kNameSpaceID_None) {
// Mark channel as urgent-start before load image if the image load is
// initaiated by a user interaction.
mUseUrgentStartForChannel = EventStateManager::IsHandlingUserInput();
mSrcsetTriggeringPrincipal = aMaybeScriptedPrincipal;
PictureSourceSrcsetChanged(this, attrVal.String(), aNotify);
} else if (aName == nsGkAtoms::sizes &&
aNameSpaceID == kNameSpaceID_None) {
// Mark channel as urgent-start before load image if the image load is
// initaiated by a user interaction.
mUseUrgentStartForChannel = EventStateManager::IsHandlingUserInput();
PictureSourceSizesChanged(this, attrVal.String(), aNotify);
}
return nsGenericHTMLElement::AfterSetAttr(aNameSpaceID, aName,
aValue, aOldValue,
aMaybeScriptedPrincipal,
aNotify);
}
nsresult
HTMLImageElement::OnAttrSetButNotChanged(int32_t aNamespaceID, nsAtom* aName,
const nsAttrValueOrString& aValue,
bool aNotify)
{
AfterMaybeChangeAttr(aNamespaceID, aName, aValue, nullptr, nullptr, false, aNotify);
return nsGenericHTMLElement::OnAttrSetButNotChanged(aNamespaceID, aName,
aValue, aNotify);
}
void
HTMLImageElement::AfterMaybeChangeAttr(int32_t aNamespaceID, nsAtom* aName,
const nsAttrValueOrString& aValue,
const nsAttrValue* aOldValue,
nsIPrincipal* aMaybeScriptedPrincipal,
bool aValueMaybeChanged, 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) {
// Mark channel as urgent-start before load image if the image load is
// initaiated by a user interaction.
mUseUrgentStartForChannel = EventStateManager::IsHandlingUserInput();
mSrcTriggeringPrincipal = nsContentUtils::GetAttrTriggeringPrincipal(
this, aValue.String(), aMaybeScriptedPrincipal);
if (InResponsiveMode()) {
if (mResponsiveSelector &&
mResponsiveSelector->Content() == this) {
mResponsiveSelector->SetDefaultSource(aValue.String(),
mSrcTriggeringPrincipal);
}
QueueImageLoadTask(true);
} else if (aNotify && OwnerDoc()->ShouldLoadImages()) {
// 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.
// Potentially, false could be passed here rather than aNotify since
// UpdateState will be called by SetAttrAndNotify, but there are two
// obstacles to this: 1) LoadImage will end up calling
// UpdateState(aNotify), and we do not want it to call UpdateState(false)
// when aNotify is true, and 2) When this function is called by
// OnAttrSetButNotChanged, SetAttrAndNotify will not subsequently call
// UpdateState.
LoadImage(aValue.String(), true, aNotify, eImageLoadType_Normal,
mSrcTriggeringPrincipal);
mNewRequestsWillNeedAnimationReset = false;
}
} else if (aNamespaceID == kNameSpaceID_None &&
aName == nsGkAtoms::crossorigin &&
aNotify) {
if (aValueMaybeChanged && GetCORSMode() != AttrValueToCORSMode(aOldValue)) {
// 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 = GetImageReferrerPolicy();
if (!InResponsiveMode() &&
referrerPolicy != RP_Unset &&
aValueMaybeChanged &&
referrerPolicy != ReferrerPolicyFromAttr(aOldValue)) {
// 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;
}
}
// 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) {
// Mark channel as urgent-start before load image if the image load is
// initaiated by a user interaction.
mUseUrgentStartForChannel = EventStateManager::IsHandlingUserInput();
if (InResponsiveMode()) {
// per spec, full selection runs when this changes, even though
// it doesn't directly affect the source selection
QueueImageLoadTask(true);
} else if (OwnerDoc()->ShouldLoadImages()) {
// 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, IgnoreErrors());
}
}
}
void
HTMLImageElement::GetEventTargetParent(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;
}
nsGenericHTMLElement::GetEventTargetParent(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::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;
}
// Mark channel as urgent-start before load image if the image load is
// initaiated by a user interaction.
mUseUrgentStartForChannel = EventStateManager::IsHandlingUserInput();
// 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.
// Mark channel as urgent-start before load image if the image load is
// initaiated by a user interaction.
mUseUrgentStartForChannel = EventStateManager::IsHandlingUserInput();
// 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() &&
OwnerDoc()->ShouldLoadImages()) {
nsContentUtils::AddScriptRunner(
NewRunnableMethod<bool>("dom::HTMLImageElement::MaybeLoadImage",
this,
&HTMLImageElement::MaybeLoadImage,
false));
}
}
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) {
OwnerDoc()->RemoveResponsiveContent(this);
mInDocResponsiveContent = false;
}
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(bool aAlwaysForceLoad)
{
// 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(aAlwaysForceLoad, /* aNotify */ true, aAlwaysForceLoad);
if (!LoadingEnabled()) {
CancelImageRequests(true);
}
}
EventStates
HTMLImageElement::IntrinsicState() const
{
return nsGenericHTMLElement::IntrinsicState() |
nsImageLoadingContent::ImageState();
}
void
HTMLImageElement::NodeInfoChanged(nsIDocument* aOldDoc)
{
nsGenericHTMLElement::NodeInfoChanged(aOldDoc);
// Force reload image if adoption steps are run.
// If loading is temporarily disabled, don't even launch script runner.
// Otherwise script runner may run later when someone has reenabled loading.
if (LoadingEnabled() && OwnerDoc()->ShouldLoadImages()) {
// Use script runner for the case the adopt is from appendChild.
// Bug 1076583 - We still behave synchronously in the non-responsive case
nsContentUtils::AddScriptRunner(
(InResponsiveMode())
? NewRunnableMethod<bool>("dom::HTMLImageElement::QueueImageLoadTask",
this,
&HTMLImageElement::QueueImageLoadTask,
true)
: NewRunnableMethod<bool>("dom::HTMLImageElement::MaybeLoadImage",
this,
&HTMLImageElement::MaybeLoadImage,
true));
}
}
// 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,
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();
}
NS_IMETHODIMP
HTMLImageElement::GetNaturalHeight(uint32_t* aNaturalHeight)
{
*aNaturalHeight = NaturalHeight();
return NS_OK;
}
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);
}
return height;
}
NS_IMETHODIMP
HTMLImageElement::GetNaturalWidth(uint32_t* aNaturalWidth)
{
*aNaturalWidth = NaturalWidth();
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);
}
return width;
}
nsresult
HTMLImageElement::CopyInnerTo(Element* aDest, bool aPreallocateChildren)
{
bool destIsStatic = aDest->OwnerDoc()->IsStaticDocument();
auto dest = static_cast<HTMLImageElement*>(aDest);
if (destIsStatic) {
CreateStaticImageClone(dest);
}
nsresult rv = nsGenericHTMLElement::CopyInnerTo(aDest, aPreallocateChildren);
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) &&
dest->OwnerDoc()->ShouldLoadImages()) {
// Mark channel as urgent-start before load image if the image load is
// initaiated by a user interaction.
mUseUrgentStartForChannel = EventStateManager::IsHandlingUserInput();
nsContentUtils::AddScriptRunner(
NewRunnableMethod<bool>("dom::HTMLImageElement::MaybeLoadImage",
dest,
&HTMLImageElement::MaybeLoadImage,
false));
}
}
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
HTMLFormElement*
HTMLImageElement::GetForm() const
{
return mForm;
}
#endif
void
HTMLImageElement::SetForm(HTMLFormElement* aForm)
{
MOZ_ASSERT(aForm, "Don't pass null here");
NS_ASSERTION(!mForm,
"We don't support switching from one non-null form to another.");
mForm = 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);
}
if (!idVal.IsEmpty()) {
mForm->RemoveImageElementFromTable(this, idVal);
}
}
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()->ShouldLoadImages()) {
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,
mUseUrgentStartForChannel);
// 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)
{
// 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;
}
nsresult
HTMLImageElement::LoadSelectedImage(bool aForce, bool aNotify, bool aAlwaysLoad)
{
double currentDensity = 1.0; // default to 1.0 for the src attribute case
// Helper to update state when only density may have changed (i.e., the source
// to load hasn't changed, and we don't do any request at all). We need (apart
// from updating our internal state) to tell the image frame because its
// intrinsic size may have changed.
//
// In the case we actually trigger a new load, that load will trigger a call
// to nsImageFrame::NotifyNewCurrentRequest, which takes care of that for us.
auto UpdateDensityOnly = [&]() -> void {
if (mCurrentDensity == currentDensity) {
return;
}
mCurrentDensity = currentDensity;
if (nsImageFrame* f = do_QueryFrame(GetPrimaryFrame())) {
f->ResponsiveContentDensityChanged();
}
};
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.
const bool sourceChanged = UpdateResponsiveSource();
if (mResponsiveSelector) {
currentDensity = mResponsiveSelector->GetSelectedImageDensity();
}
if (!sourceChanged && !aAlwaysLoad) {
UpdateDensityOnly();
return NS_OK;
}
} else if (mResponsiveSelector) {
currentDensity = mResponsiveSelector->GetSelectedImageDensity();
}
nsresult rv = NS_ERROR_FAILURE;
nsCOMPtr<nsIURI> selectedSource;
if (mResponsiveSelector) {
nsCOMPtr<nsIURI> url = mResponsiveSelector->GetSelectedImageURL();
nsCOMPtr<nsIPrincipal> triggeringPrincipal = mResponsiveSelector->GetSelectedImageTriggeringPrincipal();
selectedSource = url;
if (!aAlwaysLoad && SelectedSourceMatchesLast(selectedSource)) {
UpdateDensityOnly();
return NS_OK;
}
if (url) {
rv = LoadImage(url, aForce, aNotify, eImageLoadType_Imageset,
triggeringPrincipal);
}
} else {
nsAutoString src;
if (!GetAttr(kNameSpaceID_None, nsGkAtoms::src, src)) {
CancelImageRequests(aNotify);
rv = NS_OK;
} else {
nsIDocument* doc = OwnerDoc();
StringToURI(src, doc, getter_AddRefs(selectedSource));
if (!aAlwaysLoad && SelectedSourceMatchesLast(selectedSource)) {
UpdateDensityOnly();
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,
mSrcTriggeringPrincipal);
}
}
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.
nsCOMPtr<nsIPrincipal> principal;
if (aSourceNode == this) {
principal = mSrcsetTriggeringPrincipal;
} else if (auto* source = HTMLSourceElement::FromNode(aSourceNode)) {
principal = source->GetSrcsetTriggeringPrincipal();
}
mResponsiveSelector->SetCandidatesFromSourceSet(aNewValue, principal);
}
if (!mInDocResponsiveContent && IsInComposedDoc()) {
OwnerDoc()->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->AsElement())) {
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->AsElement())) {
// Failed to find any source
mResponsiveSelector = nullptr;
}
break;
} else if (candidateSource->IsHTMLElement(nsGkAtoms::source) &&
TryCreateResponsiveSelector(candidateSource->AsElement())) {
// 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(Element* aSourceElement)
{
MOZ_ASSERT(aSourceElement->IsHTMLElement(nsGkAtoms::source));
DebugOnly<Element *> parent(nsINode::GetParentElement());
MOZ_ASSERT(parent && parent->IsHTMLElement(nsGkAtoms::picture));
MOZ_ASSERT(IsPreviousSibling(aSourceElement, this));
// Check media and type
auto* src = static_cast<HTMLSourceElement*>(aSourceElement);
if (!src->MatchesCurrentMedia()) {
return false;
}
nsAutoString type;
if (src->GetAttr(kNameSpaceID_None, nsGkAtoms::type, type) &&
!SupportedPictureSourceType(type)) {
return false;
}
return true;
}
bool
HTMLImageElement::TryCreateResponsiveSelector(Element* aSourceElement)
{
nsCOMPtr<nsIPrincipal> principal;
// Skip if this is not a <source> with matching media query
bool isSourceTag = aSourceElement->IsHTMLElement(nsGkAtoms::source);
if (isSourceTag) {
if (!SourceElementMatches(aSourceElement)) {
return false;
}
auto* source = HTMLSourceElement::FromNode(aSourceElement);
principal = source->GetSrcsetTriggeringPrincipal();
} else if (aSourceElement->IsHTMLElement(nsGkAtoms::img)) {
// Otherwise this is the <img> tag itself
MOZ_ASSERT(aSourceElement == this);
principal = mSrcsetTriggeringPrincipal;
}
// Skip if has no srcset or an empty srcset
nsString srcset;
if (!aSourceElement->GetAttr(kNameSpaceID_None, nsGkAtoms::srcset, srcset)) {
return false;
}
if (srcset.IsEmpty()) {
return false;
}
// Try to parse
RefPtr<ResponsiveImageSelector> sel =
new ResponsiveImageSelector(aSourceElement);
if (!sel->SetCandidatesFromSourceSet(srcset, principal)) {
// No possible candidates, don't need to bother parsing sizes
return false;
}
nsAutoString sizes;
aSourceElement->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(aSourceElement == this);
nsAutoString src;
if (GetAttr(kNameSpaceID_None, nsGkAtoms::src, src) && !src.IsEmpty()) {
sel->SetDefaultSource(src, mSrcTriggeringPrincipal);
}
}
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