musicpositionappview.cpp

a position control(using in musicplayer) of symbian

#include <coemain.h>
#include <EIKENV.H>
#include "MusicPositionAppView.h"
const TInt KCallBackPeriod = 50000; // 14Hz
const TInt KOggControlFreq = 20;
_LIT(KMBMFile,"c:\\Position.mbm");
CMusicPositionAppView* CMusicPositionAppView::NewL(const TRect& aRect)
	{
	CMusicPositionAppView* self = CMusicPositionAppView::NewLC(aRect);
	CleanupStack::Pop(self);
	return self;
	}
CMusicPositionAppView* CMusicPositionAppView::NewLC(const TRect& aRect)
	{
	CMusicPositionAppView* self = new ( ELeave ) CMusicPositionAppView;
	CleanupStack::PushL(self);
	self->ConstructL(aRect);
	return self;
	}
void CMusicPositionAppView::ConstructL(const TRect& aRect)
	{
	// Create a window for this application view
	CreateWindowL();
	SetRect(aRect);
	SetComponentsToInheritVisibility(EFalse);
	LoadBackgroundBitmapL(KMBMFile,2);
	iPosition = new(ELeave)COggSlider64;
	iPosition ->SetBitmapFile(KMBMFile);
	iPosition->SetPosition(20, 150, 200 ,20);
	iPosition->SetStyle(0);
	CGulIcon* result = CEikonEnv::Static()->CreateIconL(KMBMFile, 0, 1);
	iPosition->SetKnobIcon(result);
	iPosition->SetMaxValue(240);
	AddControl(iPosition);

	
	iTimer=CPeriodic::NewL(CActive::EPriorityStandard);
	iCallBack = new(ELeave)TCallBack(CMusicPositionAppView::CallBack,this);
	
	ActivateL();
	}
CMusicPositionAppView::CMusicPositionAppView()
:iCycleFrequencyCounter(KOggControlFreq),iPoValue(0),iPlay(ETrue)
	{	
	}

CMusicPositionAppView::~CMusicPositionAppView()
	{
	if(iTimer)
		iTimer->Cancel();
	delete iTimer;
	delete iCallBack;
	ClearControls();
	}

TInt CMusicPositionAppView::CallBack(TAny* aPtr)
	{
	CMusicPositionAppView* self = (CMusicPositionAppView*) aPtr;
	self->HandleCallBack();

	return 1;
	}

void CMusicPositionAppView::HandleCallBack()
	{
	if(iPlay)
		{
		if (iCycleFrequencyCounter % 2)
			{
			CycleLowFrequencyControls();
			}
	    if(iPosition && iPoValue<=240)
	    	{
	    	iPosition->SetValue(iPoValue);
	    	}
		CycleHighFrequencyControls();
		Refresh();
		iCycleFrequencyCounter--;
		if (iCycleFrequencyCounter == 0)
			{
			// 1Hz controls
			iCycleFrequencyCounter = KOggControlFreq;
			iPoValue+=5;
			}
		}
	}
void CMusicPositionAppView::RestartCallBack()
	{
	iTimer->Cancel();
	if (!iTimer->IsActive())
		{
		iTimer->Start(TTimeIntervalMicroSeconds32(KCallBackPeriod), TTimeIntervalMicroSeconds32(KCallBackPeriod), *iCallBack);
		}
	}
void CMusicPositionAppView::StopCallBack()
	{
	if(iTimer->IsActive())
		iTimer->Cancel();
	}
// End of File