audio3eng.cpp

Symbian OS C++ 手机应用开发（第一卷）部分事例代码

/* 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) : 
    iState(ENotReady),
    iAppUi(aAppUi)
    {
    }

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_