1 2/* 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 28#ifndef LifecycleContext_h 29#define LifecycleContext_h 30 31#include "platform/LifecycleNotifier.h" 32#include "platform/LifecycleObserver.h" 33#include "wtf/HashSet.h" 34#include "wtf/OwnPtr.h" 35#include "wtf/PassOwnPtr.h" 36 37namespace blink { 38 39class Visitor; 40 41template <typename T> 42class LifecycleContext { 43public: 44 typedef LifecycleNotifier<T> Notifier; 45 typedef LifecycleObserver<T> Observer; 46 47 LifecycleContext() { } 48 virtual ~LifecycleContext() { } 49 50 virtual bool isContextThread() const { return true; } 51 52 // Called from the constructor of observers. 53 void wasObservedBy(Observer*); 54 55 // Called from the destructor of observers. 56 void wasUnobservedBy(Observer*); 57 58 virtual void trace(Visitor*) { } 59 60protected: 61 Notifier& lifecycleNotifier(); 62 63private: 64 PassOwnPtr<Notifier> createLifecycleNotifier(); 65 66 OwnPtr<Notifier> m_lifecycleNotifier; 67}; 68 69template<typename T> 70inline void LifecycleContext<T>::wasObservedBy(typename LifecycleContext<T>::Observer* observer) 71{ 72 ASSERT(isContextThread()); 73 lifecycleNotifier().addObserver(observer); 74} 75 76template<typename T> 77inline void LifecycleContext<T>::wasUnobservedBy(typename LifecycleContext<T>::Observer* observer) 78{ 79 ASSERT(isContextThread()); 80 lifecycleNotifier().removeObserver(observer); 81} 82 83template<typename T> 84inline typename LifecycleContext<T>::Notifier& LifecycleContext<T>::lifecycleNotifier() 85{ 86 if (!m_lifecycleNotifier) 87 m_lifecycleNotifier = static_cast<T*>(this)->createLifecycleNotifier(); 88 return *m_lifecycleNotifier; 89} 90 91template<typename T> 92inline PassOwnPtr<typename LifecycleContext<T>::Notifier> LifecycleContext<T>::createLifecycleNotifier() 93{ 94 return LifecycleContext<T>::Notifier::create(static_cast<T*>(this)); 95} 96 97} // namespace blink 98 99#endif // LifecycleContext_h 100