canvas/source/tools/elapsedtime.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
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   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 #include <sal/config.h>
  21
  22 #include <canvas/elapsedtime.hxx>
  23
  24 #include <tools/time.hxx>
  25 #include <utility>
  26
  27 namespace canvas::tools {
  28
  29 double ElapsedTime::getSystemTime()
  30 {
  31     return ::tools::Time::GetMonotonicTicks() / 1.0E6;
  32 }
  33
  34 ElapsedTime::ElapsedTime()
  35     : m_pTimeBase(),
  36       m_fLastQueriedTime( 0.0 ),
  37       m_fStartTime( getSystemTime() ),
  38       m_fFrozenTime( 0.0 ),
  39       m_bInPauseMode( false ),
  40       m_bInHoldMode( false )
  41 {
  42 }
  43
  44 ElapsedTime::ElapsedTime(
  45     std::shared_ptr<ElapsedTime> pTimeBase )
  46     : m_pTimeBase(std::move( pTimeBase )),
  47       m_fLastQueriedTime( 0.0 ),
  48       m_fStartTime( getCurrentTime() ),
  49       m_fFrozenTime( 0.0 ),
  50       m_bInPauseMode( false ),
  51       m_bInHoldMode( false )
  52 {
  53 }
  54
  55 void ElapsedTime::reset()
  56 {
  57     m_fLastQueriedTime = 0.0;
  58     m_fStartTime = getCurrentTime();
  59     m_fFrozenTime = 0.0;
  60     m_bInPauseMode = false;
  61     m_bInHoldMode = false;
  62 }
  63
  64 void ElapsedTime::adjustTimer( double fOffset )
  65 {
  66     // to make getElapsedTime() become _larger_, have to reduce
  67     // m_fStartTime.
  68     m_fStartTime -= fOffset;
  69
  70     // also adjust frozen time, this method must _always_ affect the
  71     // value returned by getElapsedTime()!
  72     if (m_bInHoldMode || m_bInPauseMode)
  73         m_fFrozenTime += fOffset;
  74 }
  75
  76 double ElapsedTime::getCurrentTime() const
  77 {
  78     return m_pTimeBase == nullptr ? getSystemTime() : m_pTimeBase->getElapsedTimeImpl();
  79 }
  80
  81 double ElapsedTime::getElapsedTime() const
  82 {
  83     m_fLastQueriedTime = getElapsedTimeImpl();
  84     return m_fLastQueriedTime;
  85 }
  86
  87 double ElapsedTime::getElapsedTimeImpl() const
  88 {
  89     if (m_bInHoldMode || m_bInPauseMode)
  90         return m_fFrozenTime;
  91
  92     return getCurrentTime() - m_fStartTime;
  93 }
  94
  95 void ElapsedTime::pauseTimer()
  96 {
  97     m_fFrozenTime = getElapsedTimeImpl();
  98     m_bInPauseMode = true;
  99 }
 100
 101 void ElapsedTime::continueTimer()
 102 {
 103     m_bInPauseMode = false;
 104
 105     // stop pausing, time runs again. Note that
 106     // getElapsedTimeImpl() honors hold mode, i.e. a
 107     // continueTimer() in hold mode will preserve the latter
 108     const double fPauseDuration( getElapsedTimeImpl() - m_fFrozenTime );
 109
 110     // adjust start time, such that subsequent getElapsedTime() calls
 111     // will virtually start from m_fFrozenTime.
 112     m_fStartTime += fPauseDuration;
 113 }
 114
 115 void ElapsedTime::holdTimer()
 116 {
 117     // when called during hold mode (e.g. more than once per time
 118     // object), the original hold time will be maintained.
 119     m_fFrozenTime = getElapsedTimeImpl();
 120     m_bInHoldMode = true;
 121 }
 122
 123 void ElapsedTime::releaseTimer()
 124 {
 125     m_bInHoldMode = false;
 126 }
 127
 128 } // namespace
 129
 130 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */