cintervaltimer.cpp

ARM_显示器_键盘_源代码

// ARM Ltd
// Copyright 1998 All Rights reserved

// David Earlam 22.9.1998
// helper class to call a function every n milliseconds 
// WM_TIMER (CWnd->SetTimer() is useless below 55mSecs which equates to a periodic rate
// of only 19.2 Hertz.
//
//
#include <afxwin.h>
#include "CintervalTimer.h"

#define TARGET_RESOLUTION 1  /* Try for 1-millisecond accuracy. */ 

CIntervalTimer::CIntervalTimer()
{
	m_wTimerRes=0;
	m_wTimerID=0;
}

CIntervalTimer::~CIntervalTimer()
{
	StopPeriodicTimer();
	FreeTimerResolution();
}

 
UINT CIntervalTimer::SetTimerCallback(DWORD dwUser, 
                      UINT msInterval,       /* Event interval */ 
					  LPTIMECALLBACK lpMMTimeProc    )               
                                                
{ 
        TIMECAPS tc; 

		
#if 0
        DWORD dwVersion;
        dwVersion = GetVersion();
        if (LOBYTE(LOWORD(dwVersion))<4) /*win32s*/
        {
                m_wTimerID=SetTimer(NULL,0,msInterval,(TIMERPROC)BumpProgressWin32sTimerProc);
        }
        else
#endif
        {
                if(timeGetDevCaps(&tc, sizeof(TIMECAPS)) != TIMERR_NOERROR) 
                { 
                        return TIMERR_NOCANDO; 
                } 
 
                m_wTimerRes = min(max(tc.wPeriodMin, TARGET_RESOLUTION), 
                                                tc.wPeriodMax); 
 
                timeBeginPeriod(m_wTimerRes); 
   
                m_wTimerID = timeSetEvent( 
                          msInterval,           /* Delay                        */ 
                                m_wTimerRes,            /* Resolution  */ 
                         (LPTIMECALLBACK) lpMMTimeProc, /* Callback function   */ 
                        (DWORD) dwUser,               /* User data             */ 
                        TIME_PERIODIC);               /* Event type (periodic) */ 
        }
    
        if (m_wTimerID == 0) 
        return TIMERR_NOCANDO; 
    else 
        return TIMERR_NOERROR; 
} 


void CIntervalTimer::FreeTimerResolution(void)
{
        if (m_wTimerRes != 0)
                timeEndPeriod(m_wTimerRes);
}



void CIntervalTimer::StopPeriodicTimer(void) 
{ 
    if (m_wTimerID != 0)
        {      /* If timer event is pending */ 
                DWORD dwVersion;

                dwVersion = GetVersion();
                if (LOBYTE(LOWORD(dwVersion))<4) /*win32s*/
                {
                        KillTimer(NULL,m_wTimerID);
                }
                else
                {
                        timeKillEvent(m_wTimerID);  /* Cancel the event */ 
                }
                m_wTimerID = 0;
                        
    } 
} 
 
 
#if 0
/*no multimedia timers in win32s, use a lowly WM_TIMER callback to simulate*/
void CALLBACK BumpProgressWin32sTimerProc( HWND  hwnd,/* handle of window for timer messages*/
    UINT  uMsg, /* WM_TIMER message*/
    UINT  idEvent,      /* timer identifier*/
    DWORD  dwTime )/*Universal Coordinated Time*/
{
        BumpProgressMMTimeProc(idEvent,WM_TIMER,(DWORD) &myProgressData,dwTime,0);
}
#endif