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
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 COMPUTER, INC. ``AS IS'' AND ANY
14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24  *
25  */
26 
27 #ifndef EventQueue_h
28 #define EventQueue_h
29 
30 #include <wtf/HashSet.h>
31 #include <wtf/ListHashSet.h>
32 #include <wtf/OwnPtr.h>
33 #include <wtf/RefCounted.h>
34 #include <wtf/RefPtr.h>
35 
36 namespace WebCore {
37 
38 class Event;
39 class EventQueueTimer;
40 class Node;
41 class ScriptExecutionContext;
42 
43 class EventQueue : public RefCounted<EventQueue> {
44 public:
45     enum ScrollEventTargetType {
46         ScrollEventDocumentTarget,
47         ScrollEventElementTarget
48     };
49 
50     static PassRefPtr<EventQueue> create(ScriptExecutionContext*);
51     ~EventQueue();
52 
53     void enqueueEvent(PassRefPtr<Event>);
54     void enqueueOrDispatchScrollEvent(PassRefPtr<Node>, ScrollEventTargetType);
55     bool cancelEvent(Event*);
56     void cancelQueuedEvents();
57 
58 private:
59     explicit EventQueue(ScriptExecutionContext*);
60 
61     void pendingEventTimerFired();
62     void dispatchEvent(PassRefPtr<Event>);
63 
64     OwnPtr<EventQueueTimer> m_pendingEventTimer;
65     ListHashSet<RefPtr<Event> > m_queuedEvents;
66     HashSet<Node*> m_nodesWithQueuedScrollEvents;
67 
68     friend class EventQueueTimer;
69 };
70 
71 }
72 
73 #endif // EventQueue_h
74