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 // Copyright:   (c) Lukasz Michalski
   7 // Licence:     wxWindows licence
   8 /////////////////////////////////////////////////////////////////////////////
   9
  10 #ifndef _WX_UNIX_PRIVATE_TIMER_H_
  11 #define _WX_UNIX_PRIVATE_TIMER_H_
  12
  13 #if wxUSE_TIMER
  14
  15 #include "wx/private/timer.h"
  16
  17 // the type used for milliseconds is large enough for microseconds too but
  18 // introduce a synonym for it to avoid confusion
  19 typedef wxMilliClock_t wxUsecClock_t;
  20
  21 // ----------------------------------------------------------------------------
  22 // wxTimer implementation class for Unix platforms
  23 // ----------------------------------------------------------------------------
  24
  25 // NB: we have to export at least this symbol from the shared library, because
  26 //     it's used by wxDFB's wxCore
  27 class WXDLLIMPEXP_BASE wxUnixTimerImpl : public wxTimerImpl
  28 {
  29 public:
  30     wxUnixTimerImpl(wxTimer *timer);
  31     virtual ~wxUnixTimerImpl();
  32
  33     virtual bool IsRunning() const;
  34     virtual bool Start(int milliseconds = -1, bool oneShot = false);
  35     virtual void Stop();
  36
  37     // for wxTimerScheduler only: resets the internal flag indicating that the
  38     // timer is running
  39     void MarkStopped()
  40     {
  41         wxASSERT_MSG( m_isRunning, wxT("stopping non-running timer?") );
  42
  43         m_isRunning = false;
  44     }
  45
  46 private:
  47     bool m_isRunning;
  48 };
  49
  50 // ----------------------------------------------------------------------------
  51 // wxTimerSchedule: information about a single timer, used by wxTimerScheduler
  52 // ----------------------------------------------------------------------------
  53
  54 struct wxTimerSchedule
  55 {
  56     wxTimerSchedule(wxUnixTimerImpl *timer, wxUsecClock_t expiration)
  57         : m_timer(timer),
  58           m_expiration(expiration)
  59     {
  60     }
  61
  62     // the timer itself (we don't own this pointer)
  63     wxUnixTimerImpl *m_timer;
  64
  65     // the time of its next expiration, in usec
  66     wxUsecClock_t m_expiration;
  67 };
  68
  69 // the linked list of all active timers, we keep it sorted by expiration time
  70 WX_DECLARE_LIST(wxTimerSchedule, wxTimerList);
  71
  72 // ----------------------------------------------------------------------------
  73 // wxTimerScheduler: class responsible for updating all timers
  74 // ----------------------------------------------------------------------------
  75
  76 class wxTimerScheduler
  77 {
  78 public:
  79     // get the unique timer scheduler instance
  80     static wxTimerScheduler& Get()
  81     {
  82         if ( !ms_instance )
  83             ms_instance = new wxTimerScheduler;
  84
  85         return *ms_instance;
  86     }
  87
  88     // must be called on shutdown to delete the global timer scheduler
  89     static void Shutdown()
  90     {
  91         if ( ms_instance )
  92         {
  93             delete ms_instance;
  94             ms_instance = NULL;
  95         }
  96     }
  97
  98     // adds timer which should expire at the given absolute time to the list
  99     void AddTimer(wxUnixTimerImpl *timer, wxUsecClock_t expiration);
 100
 101     // remove timer from the list, called automatically from timer dtor
 102     void RemoveTimer(wxUnixTimerImpl *timer);
 103
 104
 105     // the functions below are used by the event loop implementation to monitor
 106     // and notify timers:
 107
 108     // if this function returns true, the time remaining until the next time
 109     // expiration is returned in the provided parameter (always positive or 0)
 110     //
 111     // it returns false if there are no timers
 112     bool GetNext(wxUsecClock_t *remaining) const;
 113
 114     // trigger the timer event for all timers which have expired, return true
 115     // if any did
 116     bool NotifyExpired();
 117
 118 private:
 119     // ctor and dtor are private, this is a singleton class only created by
 120     // Get() and destroyed by Shutdown()
 121     wxTimerScheduler() { }
 122     ~wxTimerScheduler();
 123
 124     // add the given timer schedule to the list in the right place
 125     //
 126     // we take ownership of the pointer "s" which must be heap-allocated
 127     void DoAddTimer(wxTimerSchedule *s);
 128
 129
 130     // the list of all currently active timers sorted by expiration
 131     wxTimerList m_timers;
 132
 133     static wxTimerScheduler *ms_instance;
 134 };
 135
 136 #endif // wxUSE_TIMER
 137
 138 #endif // _WX_UNIX_PRIVATE_TIMER_H_