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 blink {
36
37 template<typename T>
38 class LifecycleNotifier {
39 public:
40 typedef LifecycleObserver<T> Observer;
41 typedef T Context;
42
create(Context * context)43 static PassOwnPtr<LifecycleNotifier> create(Context* context)
44 {
45 return adoptPtr(new LifecycleNotifier(context));
46 }
47
48
49 virtual ~LifecycleNotifier();
50
51
52 // FIXME: this won't need to be virtual anymore.
53 virtual void addObserver(Observer*);
54 virtual void removeObserver(Observer*);
55
isIteratingOverObservers()56 bool isIteratingOverObservers() const { return m_iterating != IteratingNone; }
57
58 protected:
LifecycleNotifier(Context * context)59 explicit LifecycleNotifier(Context* context)
60 : m_iterating(IteratingNone)
61 , m_context(context)
62 {
63 }
64
context()65 Context* context() const { return m_context; }
66
67 enum IterationType {
68 IteratingNone,
69 IteratingOverAll,
70 IteratingOverActiveDOMObjects,
71 IteratingOverContextObservers,
72 IteratingOverDocumentObservers,
73 IteratingOverPageObservers,
74 IteratingOverDOMWindowObservers
75 };
76
77 IterationType m_iterating;
78
79 private:
80 typedef HashSet<Observer*> ObserverSet;
81
82 ObserverSet m_observers;
83 Context* m_context;
84 };
85
86 template<typename T>
~LifecycleNotifier()87 inline LifecycleNotifier<T>::~LifecycleNotifier()
88 {
89 TemporaryChange<IterationType> scope(this->m_iterating, IteratingOverAll);
90 for (typename ObserverSet::iterator it = m_observers.begin(); it != m_observers.end(); it = m_observers.begin()) {
91 Observer* observer = *it;
92 m_observers.remove(observer);
93 ASSERT(observer->lifecycleContext() == m_context);
94 observer->contextDestroyed();
95 }
96 }
97
98 template<typename T>
addObserver(typename LifecycleNotifier<T>::Observer * observer)99 inline void LifecycleNotifier<T>::addObserver(typename LifecycleNotifier<T>::Observer* observer)
100 {
101 RELEASE_ASSERT(m_iterating != IteratingOverAll);
102 m_observers.add(observer);
103 }
104
105 template<typename T>
removeObserver(typename LifecycleNotifier<T>::Observer * observer)106 inline void LifecycleNotifier<T>::removeObserver(typename LifecycleNotifier<T>::Observer* observer)
107 {
108 RELEASE_ASSERT(m_iterating != IteratingOverAll);
109 m_observers.remove(observer);
110 }
111
112
113
114 } // namespace blink
115
116 #endif // LifecycleNotifier_h
117