art_nav: art_nav: ntimer.h Source File

00001 /* -*- mode: C++ -*-
00002  *
00003  *  Navigator timer class
00004  *
00005  *  Copyright (C) 2007, 2010, Austin Robot Technology
00006  *
00007  *  License: Modified BSD Software License Agreement
00008  *
00009  *  $Id: ntimer.h 620 2010-09-25 01:11:51Z jack.oquin $
00010  */
00011 
00012 #ifndef _NAV_TIMER_HH_
00013 #define _NAV_TIMER_HH_
00014 
00015 #include <sys/time.h>
00016 #include <time.h>
00017 
00022 class NavTimer
00023 {
00024  public:
00025 
00027   NavTimer()
00028     {
00029       this->Cancel();
00030     };
00031 
00032   virtual ~NavTimer() {};
00033 
00035   virtual void Cancel(void)
00036   {
00037     timer_running = false;
00038   }
00039 
00047   virtual bool Check(void)
00048   {
00049     if (!timer_running)
00050       return false;                     // timer not set
00051 
00052     // decrement time remaining by the duration of one cycle
00053     time_remaining -= (1.0 / art_msgs::ArtHertz::NAVIGATOR);
00054     return (time_remaining <= 0.0);
00055   }
00056 
00061   virtual void Restart(double duration)
00062   {
00063     if (timer_running && time_remaining > 0.0)
00064       return;
00065 
00066     Start(duration);
00067   }
00068 
00070   virtual void Start(double duration)
00071   {
00072     timer_running = true;
00073     time_remaining = duration;
00074   }
00075 
00076  protected:
00077 
00078   double time_remaining;                //< time remaining until done
00079   bool timer_running;                   //< true when timer running
00080 };
00081 
00082 #endif // _NAV_TIMER_HH_