include/wx/unix/private/timer.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/unix/private/timer.h
   3 // Purpose:     wxTimer for wxBase (unix)
   4 // Author:      Lukasz Michalski
   5 // Created:     15/01/2005
   6 // RCS-ID:      $Id$
   7 // Copyright:   (c) Lukasz Michalski
   8 // Licence:     wxWindows licence
   9 /////////////////////////////////////////////////////////////////////////////
  10
  11 #ifndef _WX_UNIX_PRIVATE_TIMER_H_
  12 #define _WX_UNIX_PRIVATE_TIMER_H_
  13
  14 #include "wx/private/timer.h"
  15
  16 // the type used for milliseconds is large enough for microseconds too but
  17 // introduce a synonym for it to avoid confusion
  18 typedef wxMilliClock_t wxUsecClock_t;
  19
  20 // ----------------------------------------------------------------------------
  21 // wxTimer implementation class for Unix platforms
  22 // ----------------------------------------------------------------------------
  23
  24 class wxUnixTimerImpl : public wxTimerImpl
  25 {
  26 public:
  27     wxUnixTimerImpl(wxTimer *timer);
  28     virtual ~wxUnixTimerImpl();
  29
  30     virtual bool IsRunning() const;
  31     virtual bool Start(int milliseconds = -1, bool oneShot = false);
  32     virtual void Stop();
  33
  34 private:
  35     bool m_isRunning;
  36
  37     friend class wxTimerScheduler;
  38 };
  39
  40 // ----------------------------------------------------------------------------
  41 // wxTimerSchedule: information about a single timer, used by wxTimerScheduler
  42 // ----------------------------------------------------------------------------
  43
  44 struct wxTimerSchedule
  45 {
  46     wxTimerSchedule(wxUnixTimerImpl *timer, wxUsecClock_t expiration)
  47         : m_timer(timer),
  48           m_expiration(expiration)
  49     {
  50     }
  51
  52     // the timer itself (we don't own this pointer)
  53     wxUnixTimerImpl *m_timer;
  54
  55     // the time of its next expiration, in usec
  56     wxUsecClock_t m_expiration;
  57 };
  58
  59 // the linked list of all active timers, we keep it sorted by expiration time
  60 WX_DECLARE_LIST(wxTimerSchedule, wxTimerList);
  61
  62 // ----------------------------------------------------------------------------
  63 // wxTimerScheduler: class responsible for updating all timers
  64 // ----------------------------------------------------------------------------
  65
  66 class wxTimerScheduler
  67 {
  68 public:
  69     // get the unique timer scheduler instance
  70     static wxTimerScheduler& Get()
  71     {
  72         if ( !ms_instance )
  73             ms_instance = new wxTimerScheduler;
  74
  75         return *ms_instance;
  76     }
  77
  78     // must be called on shutdown to delete the global timer scheduler
  79     static void Shutdown()
  80     {
  81         if ( ms_instance )
  82         {
  83             delete ms_instance;
  84             ms_instance = NULL;
  85         }
  86     }
  87
  88     // adds timer which should expire at the given absolute time to the list
  89     void AddTimer(wxUnixTimerImpl *timer, wxUsecClock_t expiration);
  90
  91     // remove timer from the list, called automatically from timer dtor
  92     void RemoveTimer(wxUnixTimerImpl *timer);
  93
  94
  95     // the functions below are used by the event loop implementation to monitor
  96     // and notify timers:
  97
  98     // if this function returns true, the time remaining until the next time
  99     // expiration is returned in the provided parameter (always positive or 0)
 100     //
 101     // it returns false if there are no timers
 102     bool GetNext(wxUsecClock_t *remaining) const;
 103
 104     // trigger the timer event for all timers which have expired
 105     void NotifyExpired();
 106
 107 private:
 108     // ctor and dtor are private, this is a singleton class only created by
 109     // Get() and destroyed by Shutdown()
 110     wxTimerScheduler() { }
 111     ~wxTimerScheduler();
 112
 113     // add the given timer schedule to the list in the right place
 114     //
 115     // we take ownership of the pointer "s" which must be heap-allocated
 116     void DoAddTimer(wxTimerSchedule *s);
 117
 118
 119     // the list of all currently active timers sorted by expiration
 120     wxTimerList m_timers;
 121
 122     static wxTimerScheduler *ms_instance;
 123 };
 124
 125 // this helper function currently only exists for Unix platforms but could be
 126 // moved to wx/stopwatch.h if it turns out to be useful elsewhere
 127 //
 128 // returns the number of microseconds since the Epoch
 129 extern wxUsecClock_t wxGetLocalTimeUsec();
 130
 131 #endif // _WX_UNIX_PRIVATE_TIMER_H_