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 #if wxUSE_TIMER
  15
  16 #include "wx/private/timer.h"
  17
  18 // the type used for milliseconds is large enough for microseconds too but
  19 // introduce a synonym for it to avoid confusion
  20 typedef wxMilliClock_t wxUsecClock_t;
  21
  22 // ----------------------------------------------------------------------------
  23 // wxTimer implementation class for Unix platforms
  24 // ----------------------------------------------------------------------------
  25
  26 class wxUnixTimerImpl : public wxTimerImpl
  27 {
  28 public:
  29     wxUnixTimerImpl(wxTimer *timer);
  30     virtual ~wxUnixTimerImpl();
  31
  32     virtual bool IsRunning() const;
  33     virtual bool Start(int milliseconds = -1, bool oneShot = false);
  34     virtual void Stop();
  35
  36     // for wxTimerScheduler only: resets the internal flag indicating that the
  37     // timer is running
  38     void MarkStopped()
  39     {
  40         wxASSERT_MSG( m_isRunning, _T("stopping non-running timer?") );
  41
  42         m_isRunning = false;
  43     }
  44
  45 private:
  46     bool m_isRunning;
  47 };
  48
  49 // ----------------------------------------------------------------------------
  50 // wxTimerSchedule: information about a single timer, used by wxTimerScheduler
  51 // ----------------------------------------------------------------------------
  52
  53 struct wxTimerSchedule
  54 {
  55     wxTimerSchedule(wxUnixTimerImpl *timer, wxUsecClock_t expiration)
  56         : m_timer(timer),
  57           m_expiration(expiration)
  58     {
  59     }
  60
  61     // the timer itself (we don't own this pointer)
  62     wxUnixTimerImpl *m_timer;
  63
  64     // the time of its next expiration, in usec
  65     wxUsecClock_t m_expiration;
  66 };
  67
  68 // the linked list of all active timers, we keep it sorted by expiration time
  69 WX_DECLARE_LIST(wxTimerSchedule, wxTimerList);
  70
  71 // ----------------------------------------------------------------------------
  72 // wxTimerScheduler: class responsible for updating all timers
  73 // ----------------------------------------------------------------------------
  74
  75 class wxTimerScheduler
  76 {
  77 public:
  78     // get the unique timer scheduler instance
  79     static wxTimerScheduler& Get()
  80     {
  81         if ( !ms_instance )
  82             ms_instance = new wxTimerScheduler;
  83
  84         return *ms_instance;
  85     }
  86
  87     // must be called on shutdown to delete the global timer scheduler
  88     static void Shutdown()
  89     {
  90         if ( ms_instance )
  91         {
  92             delete ms_instance;
  93             ms_instance = NULL;
  94         }
  95     }
  96
  97     // adds timer which should expire at the given absolute time to the list
  98     void AddTimer(wxUnixTimerImpl *timer, wxUsecClock_t expiration);
  99
 100     // remove timer from the list, called automatically from timer dtor
 101     void RemoveTimer(wxUnixTimerImpl *timer);
 102
 103
 104     // the functions below are used by the event loop implementation to monitor
 105     // and notify timers:
 106
 107     // if this function returns true, the time remaining until the next time
 108     // expiration is returned in the provided parameter (always positive or 0)
 109     //
 110     // it returns false if there are no timers
 111     bool GetNext(wxUsecClock_t *remaining) const;
 112
 113     // trigger the timer event for all timers which have expired
 114     void NotifyExpired();
 115
 116 private:
 117     // ctor and dtor are private, this is a singleton class only created by
 118     // Get() and destroyed by Shutdown()
 119     wxTimerScheduler() { }
 120     ~wxTimerScheduler();
 121
 122     // add the given timer schedule to the list in the right place
 123     //
 124     // we take ownership of the pointer "s" which must be heap-allocated
 125     void DoAddTimer(wxTimerSchedule *s);
 126
 127
 128     // the list of all currently active timers sorted by expiration
 129     wxTimerList m_timers;
 130
 131     static wxTimerScheduler *ms_instance;
 132 };
 133
 134 // this helper function currently only exists for Unix platforms but could be
 135 // moved to wx/stopwatch.h if it turns out to be useful elsewhere
 136 //
 137 // returns the number of microseconds since the Epoch
 138 extern wxUsecClock_t wxGetLocalTimeUsec();
 139
 140 #endif // wxUSE_TIMER
 141
 142 #endif // _WX_UNIX_PRIVATE_TIMER_H_