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/* -*- 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 */
* Base class for all element classes as well as nsDocumentFragment. This
* provides an implementation of nsINode, implements nsIContent, provides
* utility methods for subclasses, and so forth.
#ifndef FragmentOrElement_h___
#define FragmentOrElement_h___
#include "mozilla/Attributes.h"
#include "mozilla/EnumSet.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/UniquePtr.h"
#include "nsCycleCollectionParticipant.h" // NS_DECL_CYCLE_*
#include "nsIContent.h" // base class
#include "nsIHTMLCollection.h"
class ContentUnbinder;
class nsContentList;
class nsLabelsNodeList;
class nsDOMAttributeMap;
class nsDOMTokenList;
class nsIControllers;
class nsICSSDeclaration;
class nsDOMCSSAttributeDeclaration;
class nsDOMStringMap;
class nsIURI;
namespace mozilla {
class DeclarationBlock;
enum class ContentRelevancyReason;
using ContentRelevancy = EnumSet<ContentRelevancyReason, uint8_t>;
class ElementAnimationData;
namespace dom {
struct CustomElementData;
class Element;
class PopoverData;
} // namespace dom
} // namespace mozilla
* Tearoff to use for nodes to implement nsISupportsWeakReference
class nsNodeSupportsWeakRefTearoff final : public nsISupportsWeakReference {
explicit nsNodeSupportsWeakRefTearoff(nsINode* aNode) : mNode(aNode) {}
// nsISupports
// nsISupportsWeakReference
~nsNodeSupportsWeakRefTearoff() = default;
nsCOMPtr<nsINode> mNode;
* A generic base class for DOM elements and document fragments,
* implementing many nsIContent, nsINode and Element methods.
namespace mozilla::dom {
class ShadowRoot;
class FragmentOrElement : public nsIContent {
explicit FragmentOrElement(
already_AddRefed<mozilla::dom::NodeInfo>& aNodeInfo);
explicit FragmentOrElement(
already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo);
// We want to avoid the overhead of extra function calls for
// refcounting when we're not doing refcount logging, so we can't
NS_IMETHOD QueryInterface(REFNSIID aIID, void** aInstancePtr) override;
// nsINode interface methods
virtual void GetTextContentInternal(nsAString& aTextContent,
mozilla::OOMReporter& aError) override;
virtual void SetTextContentInternal(const nsAString& aTextContent,
nsIPrincipal* aSubjectPrincipal,
mozilla::ErrorResult& aError) override;
// nsIContent interface methods
virtual already_AddRefed<nsINodeList> GetChildren(uint32_t aFilter) override;
virtual const nsTextFragment* GetText() override;
virtual uint32_t TextLength() const override;
virtual bool TextIsOnlyWhitespace() override;
virtual bool ThreadSafeTextIsOnlyWhitespace() const override;
virtual void DestroyContent() override;
virtual void SaveSubtreeState() override;
nsIHTMLCollection* Children();
uint32_t ChildElementCount() {
if (!HasChildren()) {
return 0;
return Children()->Length();
* If there are listeners for DOMNodeInserted event, fires the event on all
* aNodes
static void FireNodeInserted(Document* aDoc, nsINode* aParent,
nsTArray<nsCOMPtr<nsIContent> >& aNodes);
FragmentOrElement, nsIContent)
static void ClearContentUnbinder();
static bool CanSkip(nsINode* aNode, bool aRemovingAllowed);
static bool CanSkipInCC(nsINode* aNode);
static bool CanSkipThis(nsINode* aNode);
static void RemoveBlackMarkedNode(nsINode* aNode);
static void MarkNodeChildren(nsINode* aNode);
static void InitCCCallbacks();
* Is the HTML local name a void element?
static bool IsHTMLVoid(nsAtom* aLocalName);
virtual ~FragmentOrElement();
* Dummy CopyInnerTo so that we can use the same macros for
* Elements and DocumentFragments.
nsresult CopyInnerTo(FragmentOrElement* aDest) { return NS_OK; }
* There are a set of DOM- and scripting-specific instance variables
* that may only be instantiated when a content object is accessed
* through the DOM. Rather than burn actual slots in the content
* objects for each of these instance variables, we put them off
* in a side structure that's only allocated when the content is
* accessed through the DOM.
class nsExtendedDOMSlots : public nsIContent::nsExtendedContentSlots {
void TraverseExtendedSlots(nsCycleCollectionTraversalCallback&) final;
void UnlinkExtendedSlots(nsIContent&) final;
size_t SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const final;
* SMIL Overridde style rules (for SMIL animation of CSS properties)
* @see Element::GetSMILOverrideStyle
RefPtr<nsDOMCSSAttributeDeclaration> mSMILOverrideStyle;
* Holds any SMIL override style declaration for this element.
RefPtr<DeclarationBlock> mSMILOverrideStyleDeclaration;
* The controllers of the XUL Element.
nsCOMPtr<nsIControllers> mControllers;
* An object implementing the .labels property for this element.
RefPtr<nsLabelsNodeList> mLabelsList;
* ShadowRoot bound to the element.
RefPtr<ShadowRoot> mShadowRoot;
* Web components custom element data.
UniquePtr<CustomElementData> mCustomElementData;
* Web animations data.
UniquePtr<ElementAnimationData> mAnimations;
* PopoverData for the element.
UniquePtr<PopoverData> mPopoverData;
* Last remembered size (in CSS pixels) for the element.
Maybe<float> mLastRememberedBSize;
Maybe<float> mLastRememberedISize;
* Whether the content of this element is relevant for the purposes
* of `content-visibility: auto.
Maybe<ContentRelevancy> mContentRelevancy;
* Whether the content of this element is considered visible for
* the purposes of `content-visibility: auto.
Maybe<bool> mVisibleForContentVisibility;
class nsDOMSlots : public nsIContent::nsContentSlots {
void Traverse(nsCycleCollectionTraversalCallback&) final;
void Unlink(nsINode&) final;
size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
* The .style attribute (an interface that forwards to the actual
* style rules)
* @see nsGenericHTMLElement::GetStyle
nsCOMPtr<nsICSSDeclaration> mStyle;
* The .dataset attribute.
* @see nsGenericHTMLElement::GetDataset
nsDOMStringMap* mDataset; // [Weak]
* @see Element::Attributes
RefPtr<nsDOMAttributeMap> mAttributeMap;
* An object implementing the .children property for this element.
RefPtr<nsContentList> mChildrenList;
* An object implementing the .classList property for this element.
RefPtr<nsDOMTokenList> mClassList;
* An object implementing the .part property for this element.
RefPtr<nsDOMTokenList> mPart;
* In case ExtendedDOMSlots is needed before normal DOMSlots, an instance of
* FatSlots class, which combines those two slot types, is created.
* This way we can avoid extra allocation for ExtendedDOMSlots.
* FatSlots is useful for example when creating Custom Elements.
class FatSlots final : public nsDOMSlots, public nsExtendedDOMSlots {
FatSlots() : nsDOMSlots(), nsExtendedDOMSlots() {
SetExtendedContentSlots(this, false);
~FatSlots() final { MOZ_COUNT_DTOR(FatSlots); }
void GetMarkup(bool aIncludeSelf, nsAString& aMarkup);
void SetInnerHTMLInternal(const nsAString& aInnerHTML, ErrorResult& aError);
// Override from nsINode
nsIContent::nsContentSlots* CreateSlots() override {
return new nsDOMSlots();
nsIContent::nsExtendedContentSlots* CreateExtendedSlots() final {
return new nsExtendedDOMSlots();
nsDOMSlots* DOMSlots() { return static_cast<nsDOMSlots*>(Slots()); }
nsDOMSlots* GetExistingDOMSlots() const {
return static_cast<nsDOMSlots*>(GetExistingSlots());
nsExtendedDOMSlots* ExtendedDOMSlots() {
nsContentSlots* slots = GetExistingContentSlots();
if (!slots) {
FatSlots* fatSlots = new FatSlots();
mSlots = fatSlots;
return fatSlots;
if (!slots->GetExtendedContentSlots()) {
slots->SetExtendedContentSlots(CreateExtendedSlots(), true);
return static_cast<nsExtendedDOMSlots*>(slots->GetExtendedContentSlots());
const nsExtendedDOMSlots* GetExistingExtendedDOMSlots() const {
return static_cast<const nsExtendedDOMSlots*>(
nsExtendedDOMSlots* GetExistingExtendedDOMSlots() {
return static_cast<nsExtendedDOMSlots*>(GetExistingExtendedContentSlots());
friend class ::ContentUnbinder;
} // namespace mozilla::dom
if (NS_SUCCEEDED(rv)) return rv; \
rv = FragmentOrElement::QueryInterface(aIID, aInstancePtr); \
#endif /* FragmentOrElement_h___ */