1/* 2 * Copyright (C) 2012 Apple 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 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' 14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS 17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF 23 * THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26#ifndef EventSender_h 27#define EventSender_h 28 29#include "Timer.h" 30#include <wtf/Vector.h> 31 32namespace WebCore { 33 34template<typename T> class EventSender { 35 WTF_MAKE_NONCOPYABLE(EventSender); WTF_MAKE_FAST_ALLOCATED; 36public: 37 explicit EventSender(const AtomicString& eventType); 38 39 const AtomicString& eventType() const { return m_eventType; } 40 void dispatchEventSoon(T*); 41 void cancelEvent(T*); 42 void dispatchPendingEvents(); 43 44#ifndef NDEBUG 45 bool hasPendingEvents(T* sender) const 46 { 47 return m_dispatchSoonList.find(sender) != notFound || m_dispatchingList.find(sender) != notFound; 48 } 49#endif 50 51private: 52 void timerFired(Timer<EventSender<T>>&) { dispatchPendingEvents(); } 53 54 AtomicString m_eventType; 55 Timer<EventSender<T>> m_timer; 56 Vector<T*> m_dispatchSoonList; 57 Vector<T*> m_dispatchingList; 58}; 59 60template<typename T> EventSender<T>::EventSender(const AtomicString& eventType) 61 : m_eventType(eventType) 62 , m_timer(this, &EventSender::timerFired) 63{ 64} 65 66template<typename T> void EventSender<T>::dispatchEventSoon(T* sender) 67{ 68 m_dispatchSoonList.append(sender); 69 if (!m_timer.isActive()) 70 m_timer.startOneShot(0); 71} 72 73template<typename T> void EventSender<T>::cancelEvent(T* sender) 74{ 75 // Remove instances of this sender from both lists. 76 // Use loops because we allow multiple instances to get into the lists. 77 size_t size = m_dispatchSoonList.size(); 78 for (size_t i = 0; i < size; ++i) { 79 if (m_dispatchSoonList[i] == sender) 80 m_dispatchSoonList[i] = 0; 81 } 82 size = m_dispatchingList.size(); 83 for (size_t i = 0; i < size; ++i) { 84 if (m_dispatchingList[i] == sender) 85 m_dispatchingList[i] = 0; 86 } 87} 88 89template<typename T> void EventSender<T>::dispatchPendingEvents() 90{ 91 // Need to avoid re-entering this function; if new dispatches are 92 // scheduled before the parent finishes processing the list, they 93 // will set a timer and eventually be processed. 94 if (!m_dispatchingList.isEmpty()) 95 return; 96 97 m_timer.stop(); 98 99 m_dispatchSoonList.checkConsistency(); 100 101 m_dispatchingList.swap(m_dispatchSoonList); 102 size_t size = m_dispatchingList.size(); 103 for (size_t i = 0; i < size; ++i) { 104 if (T* sender = m_dispatchingList[i]) { 105 m_dispatchingList[i] = 0; 106 sender->dispatchPendingEvent(this); 107 } 108 } 109 m_dispatchingList.clear(); 110} 111 112} // namespace WebCore 113 114#endif // EventSender_h 115