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1 // Copyright 2016 The Chromium Authors. All rights reserved. | 1 // Copyright 2016 The Chromium Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 #include "core/dom/ElementVisibilityObserver.h" | 5 #include "core/dom/ElementVisibilityObserver.h" |
6 | 6 |
| 7 #include "bindings/core/v8/ExceptionState.h" |
7 #include "core/dom/Element.h" | 8 #include "core/dom/Element.h" |
| 9 #include "core/dom/IntersectionObserver.h" |
8 #include "core/dom/IntersectionObserverEntry.h" | 10 #include "core/dom/IntersectionObserverEntry.h" |
| 11 #include "core/dom/IntersectionObserverInit.h" |
9 #include "wtf/Functional.h" | 12 #include "wtf/Functional.h" |
10 | 13 |
11 namespace blink { | 14 namespace blink { |
12 | 15 |
13 ElementVisibilityObserver::ElementVisibilityObserver(Element* element, std::uniq
ue_ptr<VisibilityCallback> callback) | 16 ElementVisibilityObserver* ElementVisibilityObserver::create(Element* element, C
lient* client) |
14 : m_element(element) | |
15 , m_callback(std::move(callback)) | |
16 { | 17 { |
| 18 ElementVisibilityObserver* observer = new ElementVisibilityObserver(client); |
| 19 observer->start(element); |
| 20 return observer; |
| 21 } |
| 22 |
| 23 ElementVisibilityObserver::ElementVisibilityObserver(Client* client) |
| 24 : m_client(client) |
| 25 { |
| 26 DCHECK(m_client); |
17 } | 27 } |
18 | 28 |
19 ElementVisibilityObserver::~ElementVisibilityObserver() = default; | 29 ElementVisibilityObserver::~ElementVisibilityObserver() = default; |
20 | 30 |
21 void ElementVisibilityObserver::start() | 31 void ElementVisibilityObserver::start(Element* element) |
22 { | 32 { |
| 33 IntersectionObserverInit options; |
| 34 DoubleOrDoubleArray threshold; |
| 35 threshold.setDouble(std::numeric_limits<float>::min()); |
| 36 options.setThreshold(threshold); |
| 37 |
23 DCHECK(!m_intersectionObserver); | 38 DCHECK(!m_intersectionObserver); |
24 m_intersectionObserver = IntersectionObserver::create( | 39 m_intersectionObserver = IntersectionObserver::create(options, *this, ASSERT
_NO_EXCEPTION); |
25 Vector<Length>(), Vector<float>({std::numeric_limits<float>::min()}), &m
_element->document(), | |
26 WTF::bind(&ElementVisibilityObserver::onVisibilityChanged, wrapWeakPersi
stent(this))); | |
27 DCHECK(m_intersectionObserver); | 40 DCHECK(m_intersectionObserver); |
28 m_intersectionObserver->observe(m_element.release()); | 41 m_intersectionObserver->observe(element); |
29 } | 42 } |
30 | 43 |
31 void ElementVisibilityObserver::stop() | 44 void ElementVisibilityObserver::stop() |
32 { | 45 { |
33 DCHECK(m_intersectionObserver); | 46 DCHECK(m_intersectionObserver); |
34 | 47 |
35 m_intersectionObserver->disconnect(); | 48 m_intersectionObserver->disconnect(); |
36 m_intersectionObserver = nullptr; | 49 m_intersectionObserver = nullptr; |
| 50 // Client will no longer be called upon, release. |
| 51 m_client = nullptr; |
| 52 } |
| 53 |
| 54 void ElementVisibilityObserver::handleEvent(const HeapVector<Member<Intersection
ObserverEntry>>& entries, IntersectionObserver&) |
| 55 { |
| 56 if (!m_client) |
| 57 return; |
| 58 bool isVisible = entries.last()->intersectionRatio() > 0.f; |
| 59 m_client->onVisibilityChanged(isVisible); |
| 60 } |
| 61 |
| 62 ExecutionContext* ElementVisibilityObserver::getExecutionContext() const |
| 63 { |
| 64 if (!m_client) |
| 65 return nullptr; |
| 66 return m_client->getElementVisibilityExecutionContext(); |
37 } | 67 } |
38 | 68 |
39 DEFINE_TRACE(ElementVisibilityObserver) | 69 DEFINE_TRACE(ElementVisibilityObserver) |
40 { | 70 { |
41 visitor->trace(m_element); | 71 visitor->trace(m_client); |
42 visitor->trace(m_intersectionObserver); | 72 visitor->trace(m_intersectionObserver); |
43 } | 73 IntersectionObserverCallback::trace(visitor); |
44 | |
45 void ElementVisibilityObserver::onVisibilityChanged(const HeapVector<Member<Inte
rsectionObserverEntry>>& entries) | |
46 { | |
47 bool isVisible = entries.last()->intersectionRatio() > 0.f; | |
48 (*m_callback.get())(isVisible); | |
49 } | 74 } |
50 | 75 |
51 } // namespace blink | 76 } // namespace blink |
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