1 /*
2 * Copyright (C) 2008 Apple Inc. All Rights Reserved.
3 * Copyright (C) 2013 Google Inc. All Rights Reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
15 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
17 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR
18 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
19 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
20 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
21 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
22 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 *
26 */
27 #ifndef LifecycleNotifier_h
28 #define LifecycleNotifier_h
29
30 #include "platform/LifecycleObserver.h"
31 #include "wtf/HashSet.h"
32 #include "wtf/PassOwnPtr.h"
33 #include "wtf/TemporaryChange.h"
34
35 namespace WebCore {
36
37 template<typename T> class LifecycleContext;
38
39 template<typename T>
40 class LifecycleNotifier {
41 public:
42 typedef LifecycleObserver<T> Observer;
43 typedef T Context;
44
create(Context * context)45 static PassOwnPtr<LifecycleNotifier> create(Context* context)
46 {
47 return adoptPtr(new LifecycleNotifier(context));
48 }
49
50
51 virtual ~LifecycleNotifier();
52
53
54 // FIXME: this won't need to be virtual anymore.
55 virtual void addObserver(Observer*);
56 virtual void removeObserver(Observer*);
57
isIteratingOverObservers()58 bool isIteratingOverObservers() const { return m_iterating != IteratingNone; }
59
60 protected:
LifecycleNotifier(Context * context)61 explicit LifecycleNotifier(Context* context)
62 : m_iterating(IteratingNone)
63 , m_context(context)
64 {
65 }
66
context()67 Context* context() const { return m_context; }
68
69 enum IterationType {
70 IteratingNone,
71 IteratingOverAll,
72 IteratingOverActiveDOMObjects,
73 IteratingOverContextObservers,
74 IteratingOverDocumentObservers,
75 IteratingOverPageObservers,
76 IteratingOverDOMWindowObservers
77 };
78
79 IterationType m_iterating;
80
81 private:
82 typedef HashSet<Observer*> ObserverSet;
83
84 ObserverSet m_observers;
85 Context* m_context;
86 };
87
88 template<typename T>
~LifecycleNotifier()89 inline LifecycleNotifier<T>::~LifecycleNotifier()
90 {
91 TemporaryChange<IterationType> scope(this->m_iterating, IteratingOverAll);
92 for (typename ObserverSet::iterator it = m_observers.begin(); it != m_observers.end(); it = m_observers.begin()) {
93 Observer* observer = *it;
94 m_observers.remove(observer);
95 ASSERT(observer->lifecycleContext() == m_context);
96 observer->contextDestroyed();
97 }
98 }
99
100 template<typename T>
addObserver(typename LifecycleNotifier<T>::Observer * observer)101 inline void LifecycleNotifier<T>::addObserver(typename LifecycleNotifier<T>::Observer* observer)
102 {
103 RELEASE_ASSERT(m_iterating != IteratingOverAll);
104 m_observers.add(observer);
105 }
106
107 template<typename T>
removeObserver(typename LifecycleNotifier<T>::Observer * observer)108 inline void LifecycleNotifier<T>::removeObserver(typename LifecycleNotifier<T>::Observer* observer)
109 {
110 RELEASE_ASSERT(m_iterating != IteratingOverAll);
111 m_observers.remove(observer);
112 }
113
114
115
116 } // namespace WebCore
117
118 #endif // LifecycleNotifier_h
119