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1 : /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
2 : /*
3 : * This file is part of the LibreOffice project.
4 : *
5 : * This Source Code Form is subject to the terms of the Mozilla Public
6 : * License, v. 2.0. If a copy of the MPL was not distributed with this
7 : * file, You can obtain one at http://mozilla.org/MPL/2.0/.
8 : *
9 : * This file incorporates work covered by the following license notice:
10 : *
11 : * Licensed to the Apache Software Foundation (ASF) under one or more
12 : * contributor license agreements. See the NOTICE file distributed
13 : * with this work for additional information regarding copyright
14 : * ownership. The ASF licenses this file to you under the Apache
15 : * License, Version 2.0 (the "License"); you may not use this file
16 : * except in compliance with the License. You may obtain a copy of
17 : * the License at http://www.apache.org/licenses/LICENSE-2.0 .
18 : */
19 :
20 : #ifndef INCLUDED_CANVAS_ELAPSEDTIME_HXX
21 : #define INCLUDED_CANVAS_ELAPSEDTIME_HXX
22 :
23 : #include <sal/types.h>
24 :
25 : #include <boost/shared_ptr.hpp>
26 : #include <canvas/canvastoolsdllapi.h>
27 :
28 : namespace canvas
29 : {
30 : namespace tools
31 : {
32 : /** Calculate elapsed time.
33 :
34 : This class provides several time-measurement and
35 : -management functions. In its simplest use-case, it
36 : measures the time from its creation.
37 : */
38 65 : class CANVASTOOLS_DLLPUBLIC ElapsedTime
39 : {
40 : public:
41 : /** Create a new ElapsedTime object
42 :
43 : The moment of construction starts the time
44 : measurement. That means, a subsequent getElapsedTime()
45 : call will return the time difference between object
46 : creation and getElapsedTime() call.
47 : */
48 : ElapsedTime();
49 :
50 : /** Creates a new ElapsedTime object based on another
51 : timer.
52 :
53 : The moment of construction starts the time
54 : measurement. That means, a subsequent getElapsedTime()
55 : call will return the time difference between object
56 : creation and getElapsedTime() call. All time values
57 : are not taken from the system's time base, but from
58 : the provided timer.
59 : */
60 : ElapsedTime( ::boost::shared_ptr<ElapsedTime> const & pTimeBase );
61 :
62 : /** Reset the time
63 :
64 : The instance of the reset() call starts the time
65 : measurement from scratch. That means, a subsequent
66 : getElapsedTime() call will return the time difference
67 : between reset() and getElapsedTime() call.
68 : */
69 : void reset();
70 :
71 : /** Query the elapsed time
72 :
73 : This method returns the elapsed time in seconds
74 : between either the construction of this object, or the
75 : last reset() call, if any (but see the time modulation
76 : methods below, for means to modify the otherwise
77 : continuous flow of time).
78 :
79 : @return the elapsed time in seconds.
80 : */
81 : double getElapsedTime() const;
82 :
83 : /** Pauses the running timer.
84 :
85 : This method stops the time, as returned by this
86 : object, until continueTimer() is called. During this
87 : period, getElapsedTime() will always return the same
88 : time value (i.e. the instant when pauseTimer() was
89 : called).
90 : */
91 : void pauseTimer();
92 :
93 : /** Continues the paused timer.
94 :
95 : This method re-enables the time flow, that is, time
96 : starts running again for clients calling
97 : getElapsedTime(). The (subtle) difference to the
98 : holdTimer/releaseTimer() methods below is, that there
99 : is no perceived time 'jump' between the pauseTimer()
100 : call and the continueTimer() call, i.e. the time
101 : starts over with the same value it has stopped on
102 : pauseTimer().
103 : */
104 : void continueTimer();
105 :
106 : /** Adjusts the timer, hold and pause times.
107 :
108 : This method modifies the time as returned by this
109 : object by the specified amount. This affects the time
110 : as returned by getElapsedTime(), regardless of the
111 : mode (e.g. paused, or on hold).
112 :
113 : @param fOffset
114 : This value will be added to the current time, i.e. the
115 : next call to getElapsedTime() (when performed
116 : immediately) will be adjusted by fOffset.
117 :
118 : @param bLimitToLastQueriedTime
119 : Limits the given offset to the time that has been
120 : taken via getElapsedTime()
121 : */
122 : void adjustTimer( double fOffset,
123 : bool bLimitToLastQueriedTime = true );
124 :
125 : /** Holds the current time.
126 :
127 : This call makes the timer hold the current time
128 : (e.g. getElapsedTime() will return the time when
129 : holdTimer() was called), while the underlying time is
130 : running on. When releaseTimer() is called, the time
131 : will 'jump' to the then-current, underlying time. This
132 : is equivalent to pressing the "interim time" button on
133 : a stop watch, which shows this stopped time, while the
134 : clock keeps running internally.
135 : */
136 : void holdTimer();
137 :
138 : /** Releases a held timer.
139 :
140 : After this call, the timer again returns the running
141 : time on getElapsedTime().
142 : */
143 : void releaseTimer();
144 :
145 : private:
146 : static double getSystemTime();
147 : double getCurrentTime() const;
148 : double getElapsedTimeImpl() const; // does not set m_fLastQueriedTime
149 :
150 : const ::boost::shared_ptr<ElapsedTime> m_pTimeBase;
151 :
152 : /// To validate adjustTimer() calls with bLimitToLastQueriedTime=true
153 : mutable double m_fLastQueriedTime;
154 :
155 : /// Start time, from which the difference to the time base is returned
156 : double m_fStartTime;
157 :
158 : /// Instant, when last pause or hold started, relative to m_fStartTime
159 : double m_fFrozenTime;
160 :
161 : /// True, when in pause mode
162 : bool m_bInPauseMode;
163 :
164 : /// True, when in hold mode
165 : bool m_bInHoldMode;
166 : };
167 :
168 : }
169 : }
170 :
171 : #endif /* INCLUDED_CANVAS_ELAPSEDTIME_HXX */
172 :
173 : /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
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