// Copyright (c) 2004-2009 Nokia Corporation and/or its subsidiary(-ies).

// All rights reserved.

// This component and the accompanying materials are made available

// under the terms of "Eclipse Public License v1.0"

// which accompanies this distribution, and is available

// at the URL "http://www.eclipse.org/legal/epl-v10.html".

//

// Initial Contributors:

// Nokia Corporation - initial contribution.

//

// Contributors:

//

// Description:

//

// INCLUDE FILES

#include "BTGPSNmeaBuffer.h"

#include "BTGPSMessageDef.h"

#include "BTGPSPanic.h"

// EXTERNAL DATA STRUCTURES

// EXTERNAL FUNCTION PROTOTYPES  

// CONSTANTS

// Granularity

// MACROS

// LOCAL CONSTANTS AND MACROS

// MODULE DATA STRUCTURES

// LOCAL FUNCTION PROTOTYPES

// FORWARD DECLARATIONS

// ============================= LOCAL FUNCTIONS ===============================

// ============================ MEMBER FUNCTIONS ===============================

// -----------------------------------------------------------------------------

// CBTGPSNmeaBuffer::NewL

// -----------------------------------------------------------------------------

CBTGPSNmeaBuffer* CBTGPSNmeaBuffer::NewL(TInt aSize)

    {

    CBTGPSNmeaBuffer* self = new (ELeave) CBTGPSNmeaBuffer();

    CleanupStack::PushL(self);

    self->ConstructL(aSize);

    CleanupStack::Pop();

    return self;

    }

// -----------------------------------------------------------------------------

// CBTGPSNmeaBuffer::~CBTGPSNmeaBuffer

// -----------------------------------------------------------------------------

CBTGPSNmeaBuffer::~CBTGPSNmeaBuffer()

    {

    delete iBuffer;

    }

// -----------------------------------------------------------------------------

// CBTGPSNmeaBuffer::ConstructL

// -----------------------------------------------------------------------------

void CBTGPSNmeaBuffer::ConstructL(TInt aSize)

    {

    iBuffer = (TUint8*)User::AllocZL(aSize);

    iSize = aSize;

    }

// -----------------------------------------------------------------------------

// CBTGPSNmeaBuffer::CBTGPSNmeaBuffer

// C++ default constructor can NOT contain any code, that

// might leave.

// -----------------------------------------------------------------------------

CBTGPSNmeaBuffer::CBTGPSNmeaBuffer()

    {

    }

// -----------------------------------------------------------------------------

// CBTGPSNmeaBuffer::ResetBuffer

// -----------------------------------------------------------------------------

void CBTGPSNmeaBuffer::ResetBuffer()

    {

    Mem::FillZ(iBuffer,iSize);

    iBottom = 0;

    }

// -----------------------------------------------------------------------------

// CBTGPSNmeaBuffer::CurrentIndex

// -----------------------------------------------------------------------------

TInt CBTGPSNmeaBuffer::CurrentIndex() const

    {

    return iBottom;

    }

// -----------------------------------------------------------------------------

// CBTGPSNmeaBuffer::AddSentences

// -----------------------------------------------------------------------------

void CBTGPSNmeaBuffer::AddSentences(const TDesC8& aNmea)

    {

    TPtrC8 srcDes(aNmea);

    TInt srcLen = srcDes.Length();

    while(srcLen>0)

        {

        TInt maxSize = iSize-iBottom;

        TPtr8 ptr(iBuffer+iBottom, maxSize);

        TInt cpLen = Min(maxSize,srcLen);

        ptr.Copy(srcDes.Left(cpLen));

        iBottom = (iBottom+cpLen)%iSize;

        srcDes.Set(srcDes.Right(srcLen-cpLen));

        srcLen = srcDes.Length();

        }

    }

// -----------------------------------------------------------------------------

// CBTGPSNmeaBuffer::ReadSentences

// -----------------------------------------------------------------------------

TInt CBTGPSNmeaBuffer::ReadSentences(

            TDes8& aDest, 

            TInt& aBeginning) const

    {

    __ASSERT_DEBUG(aBeginning<iSize, Panic(EPanicIndexOutOfRange));

    //Clear destination descriptor

    aDest.Zero();

    TBool started = EFalse;

    TBool ended = EFalse;

    if(aBeginning==iBottom)

        {

        return KErrEof;

        }

    if(aBeginning == KBTGPSNmeaIndexNotSet)

        {

        if(iBuffer[iBottom]!=0)

            {

            //Buffer has been rotated

            aBeginning = iBottom;

            }

        else

            {

            //Read from 0 to iBottom

            aBeginning = 0;

            if(iBottom == 0)

                {

                return KErrEof;

                }

            }

        }

    do

        {

        TUint8 nextChar = iBuffer[aBeginning];

        if(nextChar == KNmeaSentenceLead)

            {

            //Mark start of NMEA sentences

            started = ETrue;

            }

        if(started && aDest.Length()<aDest.MaxLength())

            {

            aDest.Append(nextChar);

            }

        aBeginning ++;

        aBeginning = aBeginning%iSize;

        if(started && nextChar == KNmeaSentenceTerminator2)

            {

            //Mark end of the sentence.

            ended = ETrue;

            }

        }while(aBeginning!=iBottom && !ended);

    if(aDest.Length()!=0)

        {

        return KErrNone;

        }

    return KErrEof;

    }

//  End of File