summaryrefslogtreecommitdiffstats
path: root/dom/base/DOMIntersectionObserver.h
blob: b9d2da77f7ab53c52bea7671a524ff366be770ed (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
/* -*- 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 IsForProximityToViewport : bool { No, Yes };
  static IntersectionOutput Intersect(
      const IntersectionInput&, const Element&,
      IsForProximityToViewport = IsForProximityToViewport::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 Maybe<nsRect> EdgeInclusiveIntersection(const nsRect& aRect,
                                                 const nsRect& aOtherRect);

 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;
  AutoTArray<double, 1> 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 = false;
};

NS_DEFINE_STATIC_IID_ACCESSOR(DOMIntersectionObserver,
                              NS_DOM_INTERSECTION_OBSERVER_IID)

}  // namespace mozilla::dom

#endif