interface/wx/stopwatch.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        stopwatch.h
   3 // Purpose:     interface of wxStopWatch
   4 // Author:      wxWidgets team
   5 // RCS-ID:      $Id$
   6 // Licence:     wxWindows licence
   7 /////////////////////////////////////////////////////////////////////////////
   8
   9 /**
  10     @class wxStopWatch
  11
  12     The wxStopWatch class allow you to measure time intervals.
  13
  14     For example, you may use it to measure the time elapsed by some function:
  15
  16     @code
  17         wxStopWatch sw;
  18         CallLongRunningFunction();
  19         wxLogMessage("The long running function took %ldms to execute",
  20                      sw.Time());
  21         sw.Pause();
  22         ... stopwatch is stopped now ...
  23         sw.Resume();
  24         CallLongRunningFunction();
  25         wxLogMessage("And calling it twice took $ldms in all", sw.Time());
  26     @endcode
  27
  28     Since wxWidgets 2.9.3 this class uses @c ::QueryPerformanceCounter()
  29     function under MSW to measure the elapsed time. It provides higher
  30     precision than the usual timer functions but can suffer from bugs in its
  31     implementation in some Windows XP versions. If you encounter such problems,
  32     installing a Microsoft hot fix from http://support.microsoft.com/?id=896256
  33     could be necessary.
  34
  35     @library{wxbase}
  36     @category{misc}
  37
  38     @see wxTimer
  39 */
  40 class wxStopWatch
  41 {
  42 public:
  43     /**
  44         Constructor. This starts the stop watch.
  45     */
  46     wxStopWatch();
  47
  48     /**
  49         Pauses the stop watch. Call Resume() to resume time measuring again.
  50
  51         If this method is called several times, @c Resume() must be called the same
  52         number of times to really resume the stop watch. You may, however, call
  53         Start() to resume it unconditionally.
  54     */
  55     void Pause();
  56
  57     /**
  58         Resumes the stop watch which had been paused with Pause().
  59     */
  60     void Resume();
  61
  62     /**
  63         (Re)starts the stop watch with a given initial value.
  64
  65         The stopwatch will always be running after calling Start(), even if
  66         Pause() had been called before and even if it had been called multiple
  67         times.
  68     */
  69     void Start(long milliseconds = 0);
  70
  71     /**
  72         Returns the time in milliseconds since the start (or restart) or the last
  73         call of Pause().
  74
  75         @see TimeInMicro()
  76     */
  77     long Time() const;
  78
  79     /**
  80         Returns elapsed time in microseconds.
  81
  82         This method is similar to Time() but returns the elapsed time in
  83         microseconds and not milliseconds. Notice that not all platforms really
  84         can measure times with this precision.
  85
  86         @since 2.9.3
  87      */
  88     wxLongLong TimeInMicro() const;
  89 };
  90