1/*
2 * Copyright (C) 2011 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 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#ifndef Clock_h
27#define Clock_h
28
29#include "platform/PlatformExport.h"
30#include "wtf/PassOwnPtr.h"
31#include "wtf/RefCounted.h"
32
33namespace blink {
34
35class PLATFORM_EXPORT Clock {
36public:
37    static PassOwnPtr<Clock> create();
38
39    void setCurrentTime(double);
40    double currentTime() const;
41
42    void setPlayRate(double);
43    double playRate() const { return m_rate; }
44
45    void start();
46    void stop();
47    bool isRunning() const { return m_running; }
48
49private:
50    Clock();
51    double now() const;
52    double currentDelta() const;
53
54    bool m_running;
55    double m_rate;
56    double m_offset;
57    double m_startTime;
58    mutable double m_lastTime;
59};
60
61}
62
63#endif
64