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 // NB: we have to export at least this symbol from the shared library, because
  27 //     it's used by wxDFB's wxCore
  28 class WXDLLIMPEXP_BASE wxUnixTimerImpl : public wxTimerImpl
  29 {
  30 public:
  31     wxUnixTimerImpl(wxTimer *timer);
  32     virtual ~wxUnixTimerImpl();
  33
  34     virtual bool IsRunning() const;
  35     virtual bool Start(int milliseconds = -1, bool oneShot = false);
  36     virtual void Stop();
  37
  38     // for wxTimerScheduler only: resets the internal flag indicating that the
  39     // timer is running
  40     void MarkStopped()
  41     {
  42         wxASSERT_MSG( m_isRunning, wxT("stopping non-running timer?") );
  43
  44         m_isRunning = false;
  45     }
  46
  47 private:
  48     bool m_isRunning;
  49 };
  50
  51 // ----------------------------------------------------------------------------
  52 // wxTimerSchedule: information about a single timer, used by wxTimerScheduler
  53 // ----------------------------------------------------------------------------
  54
  55 struct wxTimerSchedule
  56 {
  57     wxTimerSchedule(wxUnixTimerImpl *timer, wxUsecClock_t expiration)
  58         : m_timer(timer),
  59           m_expiration(expiration)
  60     {
  61     }
  62
  63     // the timer itself (we don't own this pointer)
  64     wxUnixTimerImpl *m_timer;
  65
  66     // the time of its next expiration, in usec
  67     wxUsecClock_t m_expiration;
  68 };
  69
  70 // the linked list of all active timers, we keep it sorted by expiration time
  71 WX_DECLARE_LIST(wxTimerSchedule, wxTimerList);
  72
  73 // ----------------------------------------------------------------------------
  74 // wxTimerScheduler: class responsible for updating all timers
  75 // ----------------------------------------------------------------------------
  76
  77 class wxTimerScheduler
  78 {
  79 public:
  80     // get the unique timer scheduler instance
  81     static wxTimerScheduler& Get()
  82     {
  83         if ( !ms_instance )
  84             ms_instance = new wxTimerScheduler;
  85
  86         return *ms_instance;
  87     }
  88
  89     // must be called on shutdown to delete the global timer scheduler
  90     static void Shutdown()
  91     {
  92         if ( ms_instance )
  93         {
  94             delete ms_instance;
  95             ms_instance = NULL;
  96         }
  97     }
  98
  99     // adds timer which should expire at the given absolute time to the list
 100     void AddTimer(wxUnixTimerImpl *timer, wxUsecClock_t expiration);
 101
 102     // remove timer from the list, called automatically from timer dtor
 103     void RemoveTimer(wxUnixTimerImpl *timer);
 104
 105
 106     // the functions below are used by the event loop implementation to monitor
 107     // and notify timers:
 108
 109     // if this function returns true, the time remaining until the next time
 110     // expiration is returned in the provided parameter (always positive or 0)
 111     //
 112     // it returns false if there are no timers
 113     bool GetNext(wxUsecClock_t *remaining) const;
 114
 115     // trigger the timer event for all timers which have expired, return true
 116     // if any did
 117     bool NotifyExpired();
 118
 119 private:
 120     // ctor and dtor are private, this is a singleton class only created by
 121     // Get() and destroyed by Shutdown()
 122     wxTimerScheduler() { }
 123     ~wxTimerScheduler();
 124
 125     // add the given timer schedule to the list in the right place
 126     //
 127     // we take ownership of the pointer "s" which must be heap-allocated
 128     void DoAddTimer(wxTimerSchedule *s);
 129
 130
 131     // the list of all currently active timers sorted by expiration
 132     wxTimerList m_timers;
 133
 134     static wxTimerScheduler *ms_instance;
 135 };
 136
 137 // this helper function currently only exists for Unix platforms but could be
 138 // moved to wx/stopwatch.h if it turns out to be useful elsewhere
 139 //
 140 // returns the number of microseconds since the Epoch
 141 extern wxUsecClock_t wxGetLocalTimeUsec();
 142
 143 #endif // wxUSE_TIMER
 144
 145 #endif // _WX_UNIX_PRIVATE_TIMER_H_