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      1 /*
      2  * Copyright (C) 2010 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 "ScopedEventQueue.h"
     33 
     34 #include "Event.h"
     35 #include "EventTarget.h"
     36 
     37 namespace WebCore {
     38 
     39 ScopedEventQueue* ScopedEventQueue::s_instance = 0;
     40 
     41 ScopedEventQueue::ScopedEventQueue()
     42     : m_scopingLevel(0)
     43 {
     44 }
     45 
     46 ScopedEventQueue::~ScopedEventQueue()
     47 {
     48     ASSERT(!m_scopingLevel);
     49     ASSERT(!m_queuedEvents.size());
     50 }
     51 
     52 void ScopedEventQueue::initialize()
     53 {
     54     ASSERT(!s_instance);
     55     OwnPtr<ScopedEventQueue> instance = adoptPtr(new ScopedEventQueue);
     56     s_instance = instance.leakPtr();
     57 }
     58 
     59 void ScopedEventQueue::enqueueEvent(PassRefPtr<Event> event)
     60 {
     61     if (m_scopingLevel)
     62         m_queuedEvents.append(event);
     63     else
     64         dispatchEvent(event);
     65 }
     66 
     67 void ScopedEventQueue::dispatchAllEvents()
     68 {
     69     Vector<RefPtr<Event> > queuedEvents;
     70     queuedEvents.swap(m_queuedEvents);
     71 
     72     for (size_t i = 0; i < queuedEvents.size(); i++)
     73         dispatchEvent(queuedEvents[i].release());
     74 }
     75 
     76 void ScopedEventQueue::dispatchEvent(PassRefPtr<Event> event) const
     77 {
     78     RefPtr<EventTarget> eventTarget = event->target();
     79     eventTarget->dispatchEvent(event);
     80 }
     81 
     82 ScopedEventQueue* ScopedEventQueue::instance()
     83 {
     84     if (!s_instance)
     85         initialize();
     86 
     87     return s_instance;
     88 }
     89 
     90 void ScopedEventQueue::incrementScopingLevel()
     91 {
     92     m_scopingLevel++;
     93 }
     94 
     95 void ScopedEventQueue::decrementScopingLevel()
     96 {
     97     ASSERT(m_scopingLevel);
     98     m_scopingLevel--;
     99     if (!m_scopingLevel)
    100         dispatchAllEvents();
    101 }
    102 
    103 }
    104