audio3eng.cpp

Symbian OS C++ 程序开发事例

/* Copyright (c) 2004, Symbian Software Ltd. All rights reserved */

#ifndef __Audio3ENG_H_
#define __Audio3ENG_H_

#include "Audio3eng.h"
#include "Audio3Ui.h"
#include "Audio3.hrh"

#include <mda\common\audio.h>
#include <e32math.h>

CAudio3Engine::CAudio3Engine(CAudio3Ui& aAppUi) : 
	iAppUi(aAppUi),
    iState(ENotReady)
    {
    }

CAudio3Engine* CAudio3Engine::NewL(CAudio3Ui& aAppUi)
    {
    CAudio3Engine* self = NewLC(aAppUi);
    CleanupStack::Pop();  // self
    return self;
    }

CAudio3Engine* CAudio3Engine::NewLC(CAudio3Ui& aAppUi)
    {
    CAudio3Engine* self = new (ELeave) CAudio3Engine(aAppUi);
    CleanupStack::PushL(self);
    self->ConstructL();
    return self;
    }

void CAudio3Engine::ConstructL()
    {
    }

void CAudio3Engine::SetFileL(const TDesC& /*aFileName*/)
	{
	}

CAudio3Engine::~CAudio3Engine()
    {
    delete iSynchronousExampleStream;    
    iSynchronousExampleStream = NULL;

    delete iAsynchronousExampleStream;    
    iAsynchronousExampleStream = NULL;
    }

void CAudio3Engine::StopL()
	{
	if (iSynchronousExampleStream)
		{
		iSynchronousExampleStream->Stop();	
		iState=EReadySynchronous;
		}
	else
		{
		iAsynchronousExampleStream->Stop();	
		iState=EReadyAsynchronous;
		}
	}

void CAudio3Engine::CreateSynchronousExample()
	{
	delete iSynchronousExampleStream;
	iSynchronousExampleStream=NULL;

	delete iAsynchronousExampleStream;
	iAsynchronousExampleStream=NULL;
	
	iSynchronousExampleStream= new (ELeave) CSynchronousExampleStream;
	iSynchronousExampleStream->ConstructL(this);
	}

void CAudio3Engine::CreateAsynchronousExample()
	{
	delete iSynchronousExampleStream;
	iSynchronousExampleStream=NULL;

	delete iAsynchronousExampleStream;
	iAsynchronousExampleStream=NULL;
	
	iAsynchronousExampleStream= new (ELeave) CAsynchronousExampleStream;
	iAsynchronousExampleStream->ConstructL(this);
	}

void CAudio3Engine::PlayL()
	{
	if (iSynchronousExampleStream)
		iSynchronousExampleStream->StartPlayL();
	else
		iAsynchronousExampleStream->StartPlayL();
	iState=EPlaying;
	}

void CSynchronousExampleStream::MaoscBufferCopied(TInt aError, const TDesC8& /*aBuffer*/)
	{
	if (aError==KErrNone || aError==KErrAbort)//user selected "Stop"
		NextBuffer();
	else
		User::Invariant();
	}

void CSynchronousExampleStream::MaoscOpenComplete(TInt aError)
	{
	if (aError==KErrNone)
		{
		iStream->SetAudioPropertiesL(TMdaAudioDataSettings::ESampleRate8000Hz,TMdaAudioDataSettings::EChannelsMono);
		iStream->SetVolume(iStream->MaxVolume());
		iEngine->SetState(CAudio3Engine::EReadySynchronous);
		}
	}

void CSynchronousExampleStream::MaoscPlayComplete(TInt aError)
	{
	if (aError==KErrNone || aError==KErrCancel)//user selected "Stop"
		{
		iEngine->SetState(CAudio3Engine::EReadySynchronous);
		PlayEnded(aError);
		}
	else
		User::Invariant();
	}

_LIT(KFileName, "testing123.raw");

void CSynchronousExampleStream::OpenFileL()
	{
	User::LeaveIfError(iSession.Connect());
	User::LeaveIfError(iFile.Open(iSession,KFileName,EFileShareAny));
	}

void CSynchronousExampleStream::CloseFile()
	{
	iFile.Close();
	iSession.Close();
	}

void CSynchronousExampleStream::StartPlayL()
	{
	iFileError=KErrNone;
	OpenFileL();
	NextBuffer();
	}
	
CSynchronousExampleStream::~CSynchronousExampleStream()
	{
	delete iStream;
	CloseFile();
	}

void CSynchronousExampleStream::PlayEnded(TInt /*aError*/)
	{
	CloseFile();
	}

void CSynchronousExampleStream::ConstructL(CAudio3Engine* aEngine)
	{
	iEngine=aEngine;
	iStream=CMdaAudioOutputStream::NewL(*this);
	iStream->Open(NULL);
	}

TInt CSynchronousExampleStream::FillBuffer()
	{
	TInt err=iFile.Read(iBuffer);
	if (err==KErrNone)
		if (iBuffer.Length() < KBufferSize)
			err=KErrEof;
	return err;
	}

void CSynchronousExampleStream::Stop()
	{
	iStream->Stop();
	}

void CAsynchronousExampleStream::Stop()
	{
	iStream->Stop();
	Cancel();	//stop any more data arriving
	}

void CSynchronousExampleStream::NextBuffer()
	{
	if (iFileError==KErrNone)
		{
		iFileError=FillBuffer();
		TRAPD(err,iStream->WriteL(iBuffer));
		if (err!=KErrNone)
			Stop();
		}
	}

CAsynchronousExampleStream::CAsynchronousExampleStream()
: CActive(EPriorityNormal)
	{
	}

const TInt KMaxDelay=50000;	

void CAsynchronousExampleStream::StartPlayL()
	{
	OpenFileL();
	iState=ETimer;
	iSeed=100;
	iTimer.After(iStatus,1);//activate RunL()
	SetActive();
	}

CAsynchronousExampleStream::~CAsynchronousExampleStream()
	{
	Cancel();
	iTimer.Close();
	delete iStream;
	CloseFile();
	}

void CAsynchronousExampleStream::ConstructL(CAudio3Engine *aEngine)
	{
	iEngine=aEngine;

	iTimer.CreateLocal();
	iStream=CMdaAudioOutputStream::NewL(*this);
	iStream->Open(NULL);
	CActiveScheduler::Add(this);
	}

void CAsynchronousExampleStream::NextBuffer(const TDesC8& aBuffer)
	{
	//assume the buffer is already there!
	ASSERT(iBufList[iReturned]==aBuffer);
	iBufList[iReturned].SetLength(0);

	if (++iReturned == KNumBuf)
		iReturned=0;
	}

void CAsynchronousExampleStream::PlayEnded(TInt /*aError*/)
	{
	CloseFile();
	iReturned=0;
	iEnd=0;
	}

void CAsynchronousExampleStream::RandomDelay()
	{
	TInt delay=	Math::Rand(iSeed) % KMaxDelay;
	iTimer.After(iStatus, delay);
	SetActive();
	}

void CAsynchronousExampleStream::DoCancel()
	{
	iTimer.Cancel();
	//if there is an outstanding file read, this can't be cancelled.
	}

void CAsynchronousExampleStream::RunL()
	{
	switch (iState)
		{
		case ETimer:
			//A buffer is available to read from the source
			if (iBufList[iEnd].Length()==0)
				{
				iFile.Read(iBufList[iEnd],iStatus);
				iState=EReading;
				SetActive();
				break;
				}
			else
				{//... but ignore it because there are no buffers free
				TInt pos=KBufferSize;
				iFile.Seek(ESeekCurrent, pos);
				RandomDelay();
				break;
				}
		case EReading:
				//Got the buffer from the source, so send it
			if (iBufList[iEnd].Length())
				{
				TRAPD(err,iStream->WriteL(iBufList[iEnd]));
				if (++iEnd==KNumBuf)
					iEnd=0;
				iState=ETimer;
				RandomDelay();
				break;
				}
			else
				{
				iFinished=ETrue;
				}
		}
	}

void CAsynchronousExampleStream::MaoscBufferCopied(TInt aError, const TDesC8& aBuffer)
	{
	if (aError==KErrNone || aError==KErrAbort)//user selected "Stop"
		NextBuffer(aBuffer);
	else
		User::Invariant();
	}

void CAsynchronousExampleStream::MaoscOpenComplete(TInt aError)
	{
	if (aError==KErrNone)
		{
		iStream->SetAudioPropertiesL(TMdaAudioDataSettings::ESampleRate8000Hz,TMdaAudioDataSettings::EChannelsMono);
		iStream->SetVolume(iStream->MaxVolume());
		iEngine->SetState(CAudio3Engine::EReadyAsynchronous);
		}
	}

void CAsynchronousExampleStream::MaoscPlayComplete(TInt aError)
	{
	if (aError==KErrNone || aError==KErrCancel)//user selected "Stop"
		{
		iEngine->SetState(CAudio3Engine::EReadyAsynchronous);
		PlayEnded(aError);
		}
	else
		User::Invariant();
	}

void CAsynchronousExampleStream::OpenFileL()
	{
	User::LeaveIfError(iSession.Connect());
	User::LeaveIfError(iFile.Open(iSession,KFileName,EFileShareAny));
	}

void CAsynchronousExampleStream::CloseFile()
	{
	iFile.Close();
	iSession.Close();
	}

void CAudio3Engine::UpdateMenu(CEikMenuPane* aMenuPane)
    {
	switch(iState)
		{
		case ENotReady:
			aMenuPane->SetItemDimmed(ECmdSynchronous, EFalse);
			aMenuPane->SetItemDimmed(ECmdAsynchronous, EFalse);
			aMenuPane->SetItemDimmed(ECmdPlay, ETrue);
			aMenuPane->SetItemDimmed(ECmdStop, ETrue);
			break;

		case EReadySynchronous:
			aMenuPane->SetItemDimmed(ECmdSynchronous, ETrue);
			aMenuPane->SetItemDimmed(ECmdAsynchronous, EFalse);
			aMenuPane->SetItemDimmed(ECmdPlay, EFalse);
			aMenuPane->SetItemDimmed(ECmdStop, ETrue);
			break;

		case EReadyAsynchronous:
			aMenuPane->SetItemDimmed(ECmdSynchronous, EFalse);
			aMenuPane->SetItemDimmed(ECmdAsynchronous, ETrue);
			aMenuPane->SetItemDimmed(ECmdPlay, EFalse);
			aMenuPane->SetItemDimmed(ECmdStop, ETrue);
			break;

		case EPlaying:
			aMenuPane->SetItemDimmed(ECmdSynchronous, ETrue);
			aMenuPane->SetItemDimmed(ECmdAsynchronous, ETrue);
			aMenuPane->SetItemDimmed(ECmdPlay, ETrue);
			aMenuPane->SetItemDimmed(ECmdStop, EFalse);
			break;
		}
	}

#endif// __Audio3ENG_H_