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