1 | /* |
2 | * Copyright (C) 2016 Apple Inc. All rights reserved. |
3 | * |
4 | * Redistribution and use in source and binary forms, with or without |
5 | * modification, are permitted provided that the following conditions |
6 | * are met: |
7 | * 1. Redistributions of source code must retain the above copyright |
8 | * notice, this list of conditions and the following disclaimer. |
9 | * 2. Redistributions in binary form must reproduce the above copyright |
10 | * notice, this list of conditions and the following disclaimer in the |
11 | * documentation and/or other materials provided with the distribution. |
12 | * |
13 | * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' |
14 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, |
15 | * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
16 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS |
17 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
18 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
19 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
20 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
21 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
22 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF |
23 | * THE POSSIBILITY OF SUCH DAMAGE. |
24 | */ |
25 | |
26 | #pragma once |
27 | |
28 | #if ENABLE(INTERSECTION_OBSERVER) |
29 | |
30 | #include "ActiveDOMObject.h" |
31 | #include "GCReachableRef.h" |
32 | #include "IntersectionObserverCallback.h" |
33 | #include "IntersectionObserverEntry.h" |
34 | #include "LengthBox.h" |
35 | #include <wtf/RefCounted.h> |
36 | #include <wtf/Variant.h> |
37 | #include <wtf/WeakPtr.h> |
38 | #include <wtf/text/WTFString.h> |
39 | |
40 | namespace WebCore { |
41 | |
42 | class Document; |
43 | class Element; |
44 | |
45 | struct IntersectionObserverRegistration { |
46 | WeakPtr<IntersectionObserver> observer; |
47 | Optional<size_t> previousThresholdIndex; |
48 | }; |
49 | |
50 | struct IntersectionObserverData { |
51 | WTF_MAKE_STRUCT_FAST_ALLOCATED; |
52 | |
53 | // IntersectionObservers for which the element that owns this IntersectionObserverData is the root. |
54 | // An IntersectionObserver is only owned by a JavaScript wrapper. ActiveDOMObject::hasPendingActivity |
55 | // is overridden to keep this wrapper alive while the observer has ongoing observations. |
56 | Vector<WeakPtr<IntersectionObserver>> observers; |
57 | |
58 | // IntersectionObserverRegistrations for which the element that owns this IntersectionObserverData is the target. |
59 | Vector<IntersectionObserverRegistration> registrations; |
60 | }; |
61 | |
62 | class IntersectionObserver : public RefCounted<IntersectionObserver>, public ActiveDOMObject, public CanMakeWeakPtr<IntersectionObserver> { |
63 | public: |
64 | struct Init { |
65 | Element* root { nullptr }; |
66 | String rootMargin; |
67 | Variant<double, Vector<double>> threshold; |
68 | }; |
69 | |
70 | static ExceptionOr<Ref<IntersectionObserver>> create(Document&, Ref<IntersectionObserverCallback>&&, Init&&); |
71 | |
72 | ~IntersectionObserver(); |
73 | |
74 | Document* trackingDocument() const { return m_root ? &m_root->document() : m_implicitRootDocument.get(); } |
75 | |
76 | Element* root() const { return m_root; } |
77 | String rootMargin() const; |
78 | const LengthBox& rootMarginBox() const { return m_rootMargin; } |
79 | const Vector<double>& thresholds() const { return m_thresholds; } |
80 | const Vector<Element*> observationTargets() const { return m_observationTargets; } |
81 | |
82 | void observe(Element&); |
83 | void unobserve(Element&); |
84 | void disconnect(); |
85 | |
86 | struct TakenRecords { |
87 | Vector<Ref<IntersectionObserverEntry>> records; |
88 | Vector<GCReachableRef<Element>> pendingTargets; |
89 | }; |
90 | TakenRecords takeRecords(); |
91 | |
92 | void targetDestroyed(Element&); |
93 | bool hasObservationTargets() const { return m_observationTargets.size(); } |
94 | void rootDestroyed(); |
95 | |
96 | bool createTimestamp(DOMHighResTimeStamp&) const; |
97 | |
98 | void appendQueuedEntry(Ref<IntersectionObserverEntry>&&); |
99 | void notify(); |
100 | |
101 | // ActiveDOMObject. |
102 | bool hasPendingActivity() const override; |
103 | const char* activeDOMObjectName() const override; |
104 | bool canSuspendForDocumentSuspension() const override; |
105 | void stop() override; |
106 | |
107 | private: |
108 | IntersectionObserver(Document&, Ref<IntersectionObserverCallback>&&, Element* root, LengthBox&& parsedRootMargin, Vector<double>&& thresholds); |
109 | |
110 | bool removeTargetRegistration(Element&); |
111 | void removeAllTargets(); |
112 | |
113 | WeakPtr<Document> m_implicitRootDocument; |
114 | Element* m_root; |
115 | LengthBox m_rootMargin; |
116 | Vector<double> m_thresholds; |
117 | RefPtr<IntersectionObserverCallback> m_callback; |
118 | Vector<Element*> m_observationTargets; |
119 | Vector<GCReachableRef<Element>> m_pendingTargets; |
120 | Vector<Ref<IntersectionObserverEntry>> m_queuedEntries; |
121 | }; |
122 | |
123 | |
124 | } // namespace WebCore |
125 | |
126 | #endif // ENABLE(INTERSECTION_OBSERVER) |
127 | |