1 files changed, 161 insertions, 0 deletions
diff --git a/dom/base/DOMIntersectionObserver.h b/dom/base/DOMIntersectionObserver.h
new file mode 100644
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+++ b/dom/base/DOMIntersectionObserver.h
@@ -0,0 +1,161 @@
+/* -*- 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"
+
+namespace mozilla {
+namespace 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_SCRIPT_HOLDER_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 \
+    }                                                \
+  }
+
+class DOMIntersectionObserver final : public nsISupports,
+                                      public nsWrapperCache {
+  virtual ~DOMIntersectionObserver() { Disconnect(); }
+
+  typedef void (*NativeCallback)(
+      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);
+
+  void Update(Document* aDocument, DOMHighResTimeStamp time);
+  MOZ_CAN_RUN_SCRIPT void Notify();
+
+  static already_AddRefed<DOMIntersectionObserver> CreateLazyLoadObserver(
+      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;
+
+  // Holds raw pointers which are explicitly cleared by UnlinkTarget().
+  nsTArray<Element*> mObservationTargets;
+
+  nsTArray<RefPtr<DOMIntersectionObserverEntry>> mQueuedEntries;
+  bool mConnected;
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(DOMIntersectionObserver,
+                              NS_DOM_INTERSECTION_OBSERVER_IID)
+
+}  // namespace dom
+}  // namespace mozilla
+
+#endif