1 /*
2 * Copyright (C) 2011 Google 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 are
6 * met:
7 *
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following disclaimer
12 * in the documentation and/or other materials provided with the
13 * distribution.
14 * * Neither the name of Google Inc. nor the names of its
15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31 #include "config.h"
32 #include "core/dom/MutationObserver.h"
33
34 #include "bindings/core/v8/ExceptionState.h"
35 #include "core/dom/ExceptionCode.h"
36 #include "core/dom/Microtask.h"
37 #include "core/dom/MutationCallback.h"
38 #include "core/dom/MutationObserverInit.h"
39 #include "core/dom/MutationObserverRegistration.h"
40 #include "core/dom/MutationRecord.h"
41 #include "core/dom/Node.h"
42 #include "core/inspector/InspectorInstrumentation.h"
43 #include "wtf/MainThread.h"
44 #include <algorithm>
45
46 namespace blink {
47
48 static unsigned s_observerPriority = 0;
49
50 struct MutationObserver::ObserverLessThan {
operator ()blink::MutationObserver::ObserverLessThan51 bool operator()(const RefPtrWillBeMember<MutationObserver>& lhs, const RefPtrWillBeMember<MutationObserver>& rhs)
52 {
53 return lhs->m_priority < rhs->m_priority;
54 }
55 };
56
create(PassOwnPtr<MutationCallback> callback)57 PassRefPtrWillBeRawPtr<MutationObserver> MutationObserver::create(PassOwnPtr<MutationCallback> callback)
58 {
59 ASSERT(isMainThread());
60 return adoptRefWillBeNoop(new MutationObserver(callback));
61 }
62
MutationObserver(PassOwnPtr<MutationCallback> callback)63 MutationObserver::MutationObserver(PassOwnPtr<MutationCallback> callback)
64 : m_callback(callback)
65 , m_priority(s_observerPriority++)
66 {
67 }
68
~MutationObserver()69 MutationObserver::~MutationObserver()
70 {
71 #if !ENABLE(OILPAN)
72 ASSERT(m_registrations.isEmpty());
73 #endif
74 if (!m_records.isEmpty())
75 InspectorInstrumentation::didClearAllMutationRecords(m_callback->executionContext(), this);
76 }
77
observe(Node * node,const MutationObserverInit & observerInit,ExceptionState & exceptionState)78 void MutationObserver::observe(Node* node, const MutationObserverInit& observerInit, ExceptionState& exceptionState)
79 {
80 if (!node) {
81 exceptionState.throwDOMException(NotFoundError, "The provided node was null.");
82 return;
83 }
84
85 MutationObserverOptions options = 0;
86
87 if (observerInit.hasAttributeOldValue() && observerInit.attributeOldValue())
88 options |= AttributeOldValue;
89
90 HashSet<AtomicString> attributeFilter;
91 if (observerInit.hasAttributeFilter()) {
92 const Vector<String>& sequence = observerInit.attributeFilter();
93 for (unsigned i = 0; i < sequence.size(); ++i)
94 attributeFilter.add(AtomicString(sequence[i]));
95 options |= AttributeFilter;
96 }
97
98 bool attributes = observerInit.hasAttributes() && observerInit.attributes();
99 if (attributes || (!observerInit.hasAttributes() && (observerInit.hasAttributeOldValue() || observerInit.hasAttributeFilter())))
100 options |= Attributes;
101
102 if (observerInit.hasCharacterDataOldValue() && observerInit.characterDataOldValue())
103 options |= CharacterDataOldValue;
104
105 bool characterData = observerInit.hasCharacterData() && observerInit.characterData();
106 if (characterData || (!observerInit.hasCharacterData() && observerInit.hasCharacterDataOldValue()))
107 options |= CharacterData;
108
109 if (observerInit.childList())
110 options |= ChildList;
111
112 if (observerInit.subtree())
113 options |= Subtree;
114
115 if (!(options & Attributes)) {
116 if (options & AttributeOldValue) {
117 exceptionState.throwTypeError("The options object may only set 'attributeOldValue' to true when 'attributes' is true or not present.");
118 return;
119 }
120 if (options & AttributeFilter) {
121 exceptionState.throwTypeError("The options object may only set 'attributeFilter' when 'attributes' is true or not present.");
122 return;
123 }
124 }
125 if (!((options & CharacterData) || !(options & CharacterDataOldValue))) {
126 exceptionState.throwTypeError("The options object may only set 'characterDataOldValue' to true when 'characterData' is true or not present.");
127 return;
128 }
129
130 if (!(options & (Attributes | CharacterData | ChildList))) {
131 exceptionState.throwTypeError("The options object must set at least one of 'attributes', 'characterData', or 'childList' to true.");
132 return;
133 }
134
135 node->registerMutationObserver(*this, options, attributeFilter);
136 }
137
takeRecords()138 MutationRecordVector MutationObserver::takeRecords()
139 {
140 MutationRecordVector records;
141 records.swap(m_records);
142 InspectorInstrumentation::didClearAllMutationRecords(m_callback->executionContext(), this);
143 return records;
144 }
145
disconnect()146 void MutationObserver::disconnect()
147 {
148 m_records.clear();
149 InspectorInstrumentation::didClearAllMutationRecords(m_callback->executionContext(), this);
150 MutationObserverRegistrationSet registrations(m_registrations);
151 for (MutationObserverRegistrationSet::iterator iter = registrations.begin(); iter != registrations.end(); ++iter)
152 (*iter)->unregister();
153 ASSERT(m_registrations.isEmpty());
154 }
155
observationStarted(MutationObserverRegistration * registration)156 void MutationObserver::observationStarted(MutationObserverRegistration* registration)
157 {
158 ASSERT(!m_registrations.contains(registration));
159 m_registrations.add(registration);
160 }
161
observationEnded(MutationObserverRegistration * registration)162 void MutationObserver::observationEnded(MutationObserverRegistration* registration)
163 {
164 ASSERT(m_registrations.contains(registration));
165 m_registrations.remove(registration);
166 }
167
activeMutationObservers()168 static MutationObserverSet& activeMutationObservers()
169 {
170 DEFINE_STATIC_LOCAL(OwnPtrWillBePersistent<MutationObserverSet>, activeObservers, (adoptPtrWillBeNoop(new MutationObserverSet())));
171 return *activeObservers;
172 }
173
suspendedMutationObservers()174 static MutationObserverSet& suspendedMutationObservers()
175 {
176 DEFINE_STATIC_LOCAL(OwnPtrWillBePersistent<MutationObserverSet>, suspendedObservers, (adoptPtrWillBeNoop(new MutationObserverSet())));
177 return *suspendedObservers;
178 }
179
activateObserver(PassRefPtrWillBeRawPtr<MutationObserver> observer)180 static void activateObserver(PassRefPtrWillBeRawPtr<MutationObserver> observer)
181 {
182 if (activeMutationObservers().isEmpty())
183 Microtask::enqueueMicrotask(WTF::bind(&MutationObserver::deliverMutations));
184
185 activeMutationObservers().add(observer);
186 }
187
enqueueMutationRecord(PassRefPtrWillBeRawPtr<MutationRecord> mutation)188 void MutationObserver::enqueueMutationRecord(PassRefPtrWillBeRawPtr<MutationRecord> mutation)
189 {
190 ASSERT(isMainThread());
191 m_records.append(mutation);
192 activateObserver(this);
193 InspectorInstrumentation::didEnqueueMutationRecord(m_callback->executionContext(), this);
194 }
195
setHasTransientRegistration()196 void MutationObserver::setHasTransientRegistration()
197 {
198 ASSERT(isMainThread());
199 activateObserver(this);
200 }
201
getObservedNodes() const202 WillBeHeapHashSet<RawPtrWillBeMember<Node> > MutationObserver::getObservedNodes() const
203 {
204 WillBeHeapHashSet<RawPtrWillBeMember<Node> > observedNodes;
205 for (MutationObserverRegistrationSet::const_iterator iter = m_registrations.begin(); iter != m_registrations.end(); ++iter)
206 (*iter)->addRegistrationNodesToSet(observedNodes);
207 return observedNodes;
208 }
209
canDeliver()210 bool MutationObserver::canDeliver()
211 {
212 return !m_callback->executionContext()->activeDOMObjectsAreSuspended();
213 }
214
deliver()215 void MutationObserver::deliver()
216 {
217 ASSERT(canDeliver());
218
219 // Calling clearTransientRegistrations() can modify m_registrations, so it's necessary
220 // to make a copy of the transient registrations before operating on them.
221 WillBeHeapVector<RawPtrWillBeMember<MutationObserverRegistration>, 1> transientRegistrations;
222 for (MutationObserverRegistrationSet::iterator iter = m_registrations.begin(); iter != m_registrations.end(); ++iter) {
223 if ((*iter)->hasTransientRegistrations())
224 transientRegistrations.append(*iter);
225 }
226 for (size_t i = 0; i < transientRegistrations.size(); ++i)
227 transientRegistrations[i]->clearTransientRegistrations();
228
229 if (m_records.isEmpty())
230 return;
231
232 MutationRecordVector records;
233 records.swap(m_records);
234
235 InspectorInstrumentation::willDeliverMutationRecords(m_callback->executionContext(), this);
236 m_callback->call(records, this);
237 InspectorInstrumentation::didDeliverMutationRecords(m_callback->executionContext());
238 }
239
resumeSuspendedObservers()240 void MutationObserver::resumeSuspendedObservers()
241 {
242 ASSERT(isMainThread());
243 if (suspendedMutationObservers().isEmpty())
244 return;
245
246 MutationObserverVector suspended;
247 copyToVector(suspendedMutationObservers(), suspended);
248 for (size_t i = 0; i < suspended.size(); ++i) {
249 if (suspended[i]->canDeliver()) {
250 suspendedMutationObservers().remove(suspended[i]);
251 activateObserver(suspended[i]);
252 }
253 }
254 }
255
deliverMutations()256 void MutationObserver::deliverMutations()
257 {
258 ASSERT(isMainThread());
259 MutationObserverVector observers;
260 copyToVector(activeMutationObservers(), observers);
261 activeMutationObservers().clear();
262 std::sort(observers.begin(), observers.end(), ObserverLessThan());
263 for (size_t i = 0; i < observers.size(); ++i) {
264 if (observers[i]->canDeliver())
265 observers[i]->deliver();
266 else
267 suspendedMutationObservers().add(observers[i]);
268 }
269 }
270
trace(Visitor * visitor)271 void MutationObserver::trace(Visitor* visitor)
272 {
273 #if ENABLE(OILPAN)
274 visitor->trace(m_records);
275 visitor->trace(m_registrations);
276 #endif
277 }
278
279 } // namespace blink
280