<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/> <title>Qwt User's Guide: QwtSystemClock Class Reference</title> <link href="tabs.css" rel="stylesheet" type="text/css"/> <link href="doxygen.css" rel="stylesheet" type="text/css"/> </head> <body> <!-- Generated by Doxygen 1.7.3 --> <div id="top"> <div id="titlearea"> <table cellspacing="0" cellpadding="0"> <tbody> <tr style="height: 56px;"> <td style="padding-left: 0.5em;"> <div id="projectname">Qwt User's Guide <span id="projectnumber">6.0.1</span></div> </td> </tr> </tbody> </table> </div> <div id="navrow1" class="tabs"> <ul class="tablist"> <li><a href="index.html"><span>Main Page</span></a></li> <li><a href="pages.html"><span>Related Pages</span></a></li> <li class="current"><a href="annotated.html"><span>Classes</span></a></li> <li><a href="files.html"><span>Files</span></a></li> </ul> </div> <div id="navrow2" class="tabs2"> <ul class="tablist"> <li><a href="annotated.html"><span>Class List</span></a></li> <li><a href="classes.html"><span>Class Index</span></a></li> <li><a href="inherits.html"><span>Class Hierarchy</span></a></li> <li><a href="functions.html"><span>Class Members</span></a></li> </ul> </div> </div> <div class="header"> <div class="summary"> <a href="#pub-methods">Public Member Functions</a> | <a href="#pub-static-methods">Static Public Member Functions</a> </div> <div class="headertitle"> <h1>QwtSystemClock Class Reference</h1> </div> </div> <div class="contents"> <!-- doxytag: class="QwtSystemClock" --> <p><a class="el" href="class_qwt_system_clock.html" title="QwtSystemClock provides high resolution clock time functions.">QwtSystemClock</a> provides high resolution clock time functions. <a href="#_details">More...</a></p> <p><code>#include <<a class="el" href="qwt__system__clock_8h_source.html">qwt_system_clock.h</a>></code></p> <p><a href="class_qwt_system_clock-members.html">List of all members.</a></p> <table class="memberdecls"> <tr><td colspan="2"><h2><a name="pub-methods"></a> Public Member Functions</h2></td></tr> <tr><td class="memItemLeft" align="right" valign="top">double </td><td class="memItemRight" valign="bottom"><a class="el" href="class_qwt_system_clock.html#a0baae39a5a9d4f4e8bf3a8bd308a6dad">elapsed</a> () const </td></tr> <tr><td class="memItemLeft" align="right" valign="top">bool </td><td class="memItemRight" valign="bottom"><a class="el" href="class_qwt_system_clock.html#a5432c09607488f9bb7e3d7592518efb1">isNull</a> () const </td></tr> <tr><td class="memItemLeft" align="right" valign="top"> </td><td class="memItemRight" valign="bottom"><a class="el" href="class_qwt_system_clock.html#a384e20d6049376575bf28306154854fd">QwtSystemClock</a> ()</td></tr> <tr><td class="memItemLeft" align="right" valign="top">double </td><td class="memItemRight" valign="bottom"><a class="el" href="class_qwt_system_clock.html#a6be327dd133c1d7ecccfb95050eef7b9">restart</a> ()</td></tr> <tr><td class="memItemLeft" align="right" valign="top">void </td><td class="memItemRight" valign="bottom"><a class="el" href="class_qwt_system_clock.html#a3408bd55b49582f7847865aacc7beb37">start</a> ()</td></tr> <tr><td class="memItemLeft" align="right" valign="top">virtual </td><td class="memItemRight" valign="bottom"><a class="el" href="class_qwt_system_clock.html#a79a46a34a317543a08a8424a333b9ee3">~QwtSystemClock</a> ()</td></tr> <tr><td colspan="2"><h2><a name="pub-static-methods"></a> Static Public Member Functions</h2></td></tr> <tr><td class="memItemLeft" align="right" valign="top">static double </td><td class="memItemRight" valign="bottom"><a class="el" href="class_qwt_system_clock.html#a1653b12f0f9a4fac9a437d516fd177ab">precision</a> ()</td></tr> </table> <hr/><a name="_details"></a><h2>Detailed Description</h2> <div class="textblock"><p><a class="el" href="class_qwt_system_clock.html" title="QwtSystemClock provides high resolution clock time functions.">QwtSystemClock</a> provides high resolution clock time functions. </p> <p>Sometimes the resolution offered by QTime ( millisecond ) is not accurate enough for implementing time measurements ( f.e. sampling ). <a class="el" href="class_qwt_system_clock.html" title="QwtSystemClock provides high resolution clock time functions.">QwtSystemClock</a> offers a subset of the QTime functionality using higher resolution timers ( if possible ).</p> <p>Precision and time intervals are multiples of milliseconds (ms).</p> <dl class="note"><dt><b>Note:</b></dt><dd>The implementation uses high-resolution performance counter on Windows, mach_absolute_time() on the Mac or POSIX timers on other systems. If none is available it falls back on QTimer. </dd></dl> </div><hr/><h2>Constructor & Destructor Documentation</h2> <a class="anchor" id="a384e20d6049376575bf28306154854fd"></a><!-- doxytag: member="QwtSystemClock::QwtSystemClock" ref="a384e20d6049376575bf28306154854fd" args="()" --> <div class="memitem"> <div class="memproto"> <table class="memname"> <tr> <td class="memname">QwtSystemClock::QwtSystemClock </td> <td>(</td> <td class="paramname"></td><td>)</td> <td></td> </tr> </table> </div> <div class="memdoc"> <p>Constructs a null clock object. </p> </div> </div> <a class="anchor" id="a79a46a34a317543a08a8424a333b9ee3"></a><!-- doxytag: member="QwtSystemClock::~QwtSystemClock" ref="a79a46a34a317543a08a8424a333b9ee3" args="()" --> <div class="memitem"> <div class="memproto"> <table class="memname"> <tr> <td class="memname">QwtSystemClock::~QwtSystemClock </td> <td>(</td> <td class="paramname"></td><td>)</td> <td><code> [virtual]</code></td> </tr> </table> </div> <div class="memdoc"> <p>Destructor. </p> </div> </div> <hr/><h2>Member Function Documentation</h2> <a class="anchor" id="a0baae39a5a9d4f4e8bf3a8bd308a6dad"></a><!-- doxytag: member="QwtSystemClock::elapsed" ref="a0baae39a5a9d4f4e8bf3a8bd308a6dad" args="() const " --> <div class="memitem"> <div class="memproto"> <table class="memname"> <tr> <td class="memname">double QwtSystemClock::elapsed </td> <td>(</td> <td class="paramname"></td><td>)</td> <td> const</td> </tr> </table> </div> <div class="memdoc"> <dl class="return"><dt><b>Returns:</b></dt><dd>Number of milliseconds that have elapsed since the last time <a class="el" href="class_qwt_system_clock.html#a3408bd55b49582f7847865aacc7beb37">start()</a> or <a class="el" href="class_qwt_system_clock.html#a6be327dd133c1d7ecccfb95050eef7b9">restart()</a> was called or 0.0 for null clocks. </dd></dl> </div> </div> <a class="anchor" id="a5432c09607488f9bb7e3d7592518efb1"></a><!-- doxytag: member="QwtSystemClock::isNull" ref="a5432c09607488f9bb7e3d7592518efb1" args="() const " --> <div class="memitem"> <div class="memproto"> <table class="memname"> <tr> <td class="memname">bool QwtSystemClock::isNull </td> <td>(</td> <td class="paramname"></td><td>)</td> <td> const</td> </tr> </table> </div> <div class="memdoc"> <dl class="return"><dt><b>Returns:</b></dt><dd>true if the clock has never been started. </dd></dl> </div> </div> <a class="anchor" id="a1653b12f0f9a4fac9a437d516fd177ab"></a><!-- doxytag: member="QwtSystemClock::precision" ref="a1653b12f0f9a4fac9a437d516fd177ab" args="()" --> <div class="memitem"> <div class="memproto"> <table class="memname"> <tr> <td class="memname">double QwtSystemClock::precision </td> <td>(</td> <td class="paramname"></td><td>)</td> <td><code> [static]</code></td> </tr> </table> </div> <div class="memdoc"> <dl class="return"><dt><b>Returns:</b></dt><dd>Accuracy of the system clock in milliseconds. </dd></dl> </div> </div> <a class="anchor" id="a6be327dd133c1d7ecccfb95050eef7b9"></a><!-- doxytag: member="QwtSystemClock::restart" ref="a6be327dd133c1d7ecccfb95050eef7b9" args="()" --> <div class="memitem"> <div class="memproto"> <table class="memname"> <tr> <td class="memname">double QwtSystemClock::restart </td> <td>(</td> <td class="paramname"></td><td>)</td> <td></td> </tr> </table> </div> <div class="memdoc"> <p>The start time to the current time and return the time, that is elapsed since the previous start time. </p> </div> </div> <a class="anchor" id="a3408bd55b49582f7847865aacc7beb37"></a><!-- doxytag: member="QwtSystemClock::start" ref="a3408bd55b49582f7847865aacc7beb37" args="()" --> <div class="memitem"> <div class="memproto"> <table class="memname"> <tr> <td class="memname">void QwtSystemClock::start </td> <td>(</td> <td class="paramname"></td><td>)</td> <td></td> </tr> </table> </div> <div class="memdoc"> <p>Sets the start time to the current time. </p> </div> </div> </div> <hr class="footer"/><address class="footer"><small>Generated by  <a href="http://www.doxygen.org/index.html"> <img class="footer" src="doxygen.png" alt="doxygen"/></a> 1.7.3 </small></address> </body> </html>