/*

* Copyright (c) 2003-2008 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:  Skin serv's file buffer.

*

*/

// INCLUDE FILES

#include "AknsSrvFileBuffer.h"

// CONSTANTS

static const int KAknsSrvFileBufSize = 10*1024;

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

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

// C++ Constructor

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

//

CAknsSrvFileBuffer::CAknsSrvFileBuffer()

    // CBase initializes: iBuffer(0), iPosition(0), iLength(0)

    {

    }

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

// Destructor

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

//

CAknsSrvFileBuffer::~CAknsSrvFileBuffer()

    {

    delete iData;

    delete iContent;

    delete iBuffer;

    }

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

// Two-phased constructor

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

//

void CAknsSrvFileBuffer::ConstructL(RFile& aFilehandle)

    {

    iBuffer = HBufC8::NewL( KAknsSrvFileBufSize );

    iContent = ContentAccess::CContent::NewL(aFilehandle);

    iData = iContent->OpenContentL(ContentAccess::EView, ContentAccess::EContentShareReadOnly);

    FillBufferL();

    }

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

// CAknsSrvFileBuffer::NewL

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

//

CAknsSrvFileBuffer* CAknsSrvFileBuffer::NewL( RFile& aFilehandle )

    {

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

    CleanupStack::PushL( self );

    self->ConstructL(aFilehandle);

    CleanupStack::Pop( self );

    return self;

    }

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

// CAknsSrvFileBuffer::GetInt32L

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

//

TInt32 CAknsSrvFileBuffer::GetInt32L( const TUint aOffset )

    {

    ReadToBufferL( aOffset, 4 );

    TInt32 value;

    Mem::Copy( &value, PtrToBuffer(aOffset), 4 );

    return value;

    }

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

// CAknsSrvFileBuffer::GetUint16L

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

//

TUint16 CAknsSrvFileBuffer::GetUint16L( const TUint aOffset )

    {

    ReadToBufferL( aOffset, 2 );

    TUint16 value;

    Mem::Copy( &value, PtrToBuffer(aOffset), 2 );

    return value;

    }

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

// CAknsSrvFileBuffer::GetInt16L

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

//

TInt16 CAknsSrvFileBuffer::GetInt16L( const TUint aOffset )

    {

    ReadToBufferL( aOffset, 2 );

    TInt16 value;

    Mem::Copy( &value, PtrToBuffer(aOffset), 2 );

    return value;

    }

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

// CAknsSrvFileBuffer::GetUint8L

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

//

TUint8 CAknsSrvFileBuffer::GetUint8L( const TUint aOffset )

    {

    ReadToBufferL( aOffset, 1 );

    TUint8 value;

    Mem::Copy( &value, PtrToBuffer(aOffset), 1 );

    return value;

    }

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

// CAknsSrvFileBuffer::PtrToBuffer

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

//

const TAny* CAknsSrvFileBuffer::PtrToBuffer( const TUint aOffset ) const

    {

    return (iBuffer->Ptr()) + aOffset - iPosition;

    }

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

// CAknsSrvFileBuffer::ReadToBufferL

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

//

void CAknsSrvFileBuffer::ReadToBufferL( const TUint aOffset, const TUint aSize )

    {

    if( IsWithin( aOffset, aSize ) )

        {

        return;

        }

    iPosition = static_cast<TInt>(aOffset);

    FillBufferL();

    if( !IsWithin( aOffset, aSize ) )

        {

        User::Leave( KErrEof );

        }

    }

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

// CAknsSrvFileBuffer::FillBufferL

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

//

void CAknsSrvFileBuffer::FillBufferL()

    {

    TPtr8 ptr( iBuffer->Des() );

    iLength = 0;

    User::LeaveIfError( iData->Seek(ESeekStart, iPosition) );

    User::LeaveIfError( iData->Read(ptr, KAknsSrvFileBufSize));

    iLength = ptr.Length();

    }

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

// CAknsSrvFileBuffer::IsWithin

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

//

TBool CAknsSrvFileBuffer::IsWithin( const TUint aOffset, const TUint aSize ) const

    {

    if( (static_cast<TInt>(aOffset) >= iPosition) &&

        (static_cast<TInt>(aOffset+aSize) <= (iPosition+iLength)) )

        {

        return ETrue;

        }

    return EFalse;

    }

//  End of File