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| -rw-r--r-- | dom/base/DOMIntersectionObserver.h | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/dom/base/DOMIntersectionObserver.h b/dom/base/DOMIntersectionObserver.h new file mode 100644 index 0000000000..a5c4a0302d --- /dev/null +++ b/dom/base/DOMIntersectionObserver.h @@ -0,0 +1,206 @@ +/* -*- 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/. */ + +#ifndef DOMIntersectionObserver_h +#define DOMIntersectionObserver_h + +#include "mozilla/Attributes.h" +#include "mozilla/dom/IntersectionObserverBinding.h" +#include "mozilla/ServoStyleConsts.h" +#include "mozilla/Variant.h" +#include "nsDOMNavigationTiming.h" +#include "nsTArray.h" +#include "nsTHashSet.h" + +namespace mozilla::dom { + +class DOMIntersectionObserver; + +class DOMIntersectionObserverEntry final : public nsISupports, + public nsWrapperCache { + ~DOMIntersectionObserverEntry() = default; + + public: + DOMIntersectionObserverEntry(nsISupports* aOwner, DOMHighResTimeStamp aTime, + RefPtr<DOMRect> aRootBounds, + RefPtr<DOMRect> aBoundingClientRect, + RefPtr<DOMRect> aIntersectionRect, + bool aIsIntersecting, Element* aTarget, + double aIntersectionRatio) + : mOwner(aOwner), + mTime(aTime), + mRootBounds(std::move(aRootBounds)), + mBoundingClientRect(std::move(aBoundingClientRect)), + mIntersectionRect(std::move(aIntersectionRect)), + mIsIntersecting(aIsIntersecting), + mTarget(aTarget), + mIntersectionRatio(aIntersectionRatio) {} + NS_DECL_CYCLE_COLLECTING_ISUPPORTS + NS_DECL_CYCLE_COLLECTION_WRAPPERCACHE_CLASS(DOMIntersectionObserverEntry) + + nsISupports* GetParentObject() const { return mOwner; } + + JSObject* WrapObject(JSContext* aCx, + JS::Handle<JSObject*> aGivenProto) override { + return IntersectionObserverEntry_Binding::Wrap(aCx, this, aGivenProto); + } + + DOMHighResTimeStamp Time() const { return mTime; } + + DOMRect* GetRootBounds() { return mRootBounds; } + + DOMRect* BoundingClientRect() { return mBoundingClientRect; } + + DOMRect* IntersectionRect() { return mIntersectionRect; } + + bool IsIntersecting() const { return mIsIntersecting; } + + double IntersectionRatio() const { return mIntersectionRatio; } + + Element* Target() { return mTarget; } + + protected: + nsCOMPtr<nsISupports> mOwner; + DOMHighResTimeStamp mTime; + RefPtr<DOMRect> mRootBounds; + RefPtr<DOMRect> mBoundingClientRect; + RefPtr<DOMRect> mIntersectionRect; + bool mIsIntersecting; + RefPtr<Element> mTarget; + double mIntersectionRatio; +}; + +#define NS_DOM_INTERSECTION_OBSERVER_IID \ + { \ + 0x8570a575, 0xe303, 0x4d18, { \ + 0xb6, 0xb1, 0x4d, 0x2b, 0x49, 0xd8, 0xef, 0x94 \ + } \ + } + +// An input suitable to compute intersections with multiple targets. +struct IntersectionInput { + // Whether the root is implicit (null, originally). + const bool mIsImplicitRoot = false; + // The computed root node. For the implicit root, this will be the in-process + // root document we can compute coordinates against (along with the remote + // document visible rect if appropriate). + const nsINode* mRootNode = nullptr; + nsIFrame* mRootFrame = nullptr; + // The rect of mRootFrame in client coordinates. + nsRect mRootRect; + // The root margin computed against the root rect. + nsMargin mRootMargin; + // If this is in an OOP iframe, the visible rect of the OOP frame. + Maybe<nsRect> mRemoteDocumentVisibleRect; +}; + +struct IntersectionOutput { + const bool mIsSimilarOrigin; + const nsRect mRootBounds; + const nsRect mTargetRect; + const Maybe<nsRect> mIntersectionRect; + + bool Intersects() const { return mIntersectionRect.isSome(); } +}; + +class DOMIntersectionObserver final : public nsISupports, + public nsWrapperCache { + virtual ~DOMIntersectionObserver() { Disconnect(); } + + using NativeCallback = void (*)( + const Sequence<OwningNonNull<DOMIntersectionObserverEntry>>& aEntries); + DOMIntersectionObserver(Document&, NativeCallback); + + public: + DOMIntersectionObserver(already_AddRefed<nsPIDOMWindowInner>&& aOwner, + dom::IntersectionCallback& aCb); + NS_DECL_CYCLE_COLLECTING_ISUPPORTS + NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(DOMIntersectionObserver) + NS_DECLARE_STATIC_IID_ACCESSOR(NS_DOM_INTERSECTION_OBSERVER_IID) + + static already_AddRefed<DOMIntersectionObserver> Constructor( + const GlobalObject&, dom::IntersectionCallback&, ErrorResult&); + static already_AddRefed<DOMIntersectionObserver> Constructor( + const GlobalObject&, dom::IntersectionCallback&, + const IntersectionObserverInit&, ErrorResult&); + + JSObject* WrapObject(JSContext* aCx, + JS::Handle<JSObject*> aGivenProto) override { + return IntersectionObserver_Binding::Wrap(aCx, this, aGivenProto); + } + + nsISupports* GetParentObject() const; + + nsINode* GetRoot() const { return mRoot; } + + void GetRootMargin(nsACString&); + bool SetRootMargin(const nsACString&); + + void GetThresholds(nsTArray<double>& aRetVal); + void Observe(Element& aTarget); + void Unobserve(Element& aTarget); + + void UnlinkTarget(Element& aTarget); + void Disconnect(); + + void TakeRecords(nsTArray<RefPtr<DOMIntersectionObserverEntry>>& aRetVal); + + static IntersectionInput ComputeInput( + const Document& aDocument, const nsINode* aRoot, + const StyleRect<LengthPercentage>* aRootMargin); + + enum class IgnoreContentVisibility : bool { No, Yes }; + static IntersectionOutput Intersect( + const IntersectionInput&, Element&, + IgnoreContentVisibility = IgnoreContentVisibility::No); + // Intersects with a given rect, already relative to the root frame. + static IntersectionOutput Intersect(const IntersectionInput&, const nsRect&); + + void Update(Document& aDocument, DOMHighResTimeStamp time); + MOZ_CAN_RUN_SCRIPT void Notify(); + + static already_AddRefed<DOMIntersectionObserver> CreateLazyLoadObserver( + Document&); + static already_AddRefed<DOMIntersectionObserver> + CreateLazyLoadObserverViewport(Document&); + + static already_AddRefed<DOMIntersectionObserver> + CreateContentVisibilityObserver(Document&); + + protected: + void Connect(); + void QueueIntersectionObserverEntry(Element* aTarget, + DOMHighResTimeStamp time, + const Maybe<nsRect>& aRootRect, + const nsRect& aTargetRect, + const Maybe<nsRect>& aIntersectionRect, + bool aIsIntersecting, + double aIntersectionRatio); + + nsCOMPtr<nsPIDOMWindowInner> mOwner; + RefPtr<Document> mDocument; + Variant<RefPtr<dom::IntersectionCallback>, NativeCallback> mCallback; + RefPtr<nsINode> mRoot; + StyleRect<LengthPercentage> mRootMargin; + nsTArray<double> mThresholds; + + // These hold raw pointers which are explicitly cleared by UnlinkTarget(). + // + // We keep a set and an array because we need ordered access, but also + // constant time lookup. + nsTArray<Element*> mObservationTargets; + nsTHashSet<Element*> mObservationTargetSet; + + nsTArray<RefPtr<DOMIntersectionObserverEntry>> mQueuedEntries; + bool mConnected; +}; + +NS_DEFINE_STATIC_IID_ACCESSOR(DOMIntersectionObserver, + NS_DOM_INTERSECTION_OBSERVER_IID) + +} // namespace mozilla::dom + +#endif |