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 #include "config.h"
27 #include "platform/Clock.h"
28
29 #include "wtf/CurrentTime.h"
30
31 namespace blink {
32
Clock()33 Clock::Clock()
34 : m_running(false)
35 , m_rate(1)
36 , m_offset(0)
37 {
38 m_startTime = m_lastTime = now();
39 }
40
setCurrentTime(double time)41 void Clock::setCurrentTime(double time)
42 {
43 m_startTime = m_lastTime = now();
44 m_offset = time;
45 }
46
currentTime() const47 double Clock::currentTime() const
48 {
49 return currentDelta() + m_offset;
50 }
51
setPlayRate(double rate)52 void Clock::setPlayRate(double rate)
53 {
54 m_offset += currentDelta();
55 m_lastTime = m_startTime = now();
56 m_rate = rate;
57 }
58
start()59 void Clock::start()
60 {
61 if (m_running)
62 return;
63
64 m_lastTime = m_startTime = now();
65 m_running = true;
66 }
67
stop()68 void Clock::stop()
69 {
70 if (!m_running)
71 return;
72
73 m_offset += currentDelta();
74 m_lastTime = m_startTime = now();
75 m_running = false;
76 }
77
now() const78 double Clock::now() const
79 {
80 return WTF::currentTime();
81 }
82
currentDelta() const83 double Clock::currentDelta() const
84 {
85 if (m_running)
86 m_lastTime = now();
87 return (m_lastTime - m_startTime) * m_rate;
88 }
89
create()90 PassOwnPtr<Clock> Clock::create()
91 {
92 return adoptPtr(new Clock());
93 }
94
95 } // namespace blink
96