/*

* Copyright (c) 2004 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:  This class provides base class for metadata source classes used

*                by different parsers.

*

*/

#ifndef CMETADATASOURCE_H

#define CMETADATASOURCE_H

// INCLUDES

#include <e32base.h>

// CLASS DECLARATION

/**

*  This class implements base class for metadata sources such as files or descriptors.

*

*  @lib MetaDataUtility.lib

*  @since 3.0

*/

class CMetaDataSource : public CBase

	{

	public:  // Destructor

		/**

		* Destructor.

		*/

		virtual ~CMetaDataSource();

	protected:  // Constructor

        /**

        * C++ default constructor.

        */

		CMetaDataSource();

    public: // New functions

        /**

        * Reads sufficient data from the source to fill the specified 8-bit descriptor

        * up to its maximum length.

        * @since 3.0

        * @param aDes Contains the data that was read

		* @param aLength How many bytes will be read

        * @return KErrNone, or one of the systemwide error codes.

		*/

		virtual void ReadL( TDes8& aDes ) = 0;

        /**

        * Reads data of specified length from the source into the specified 8-bit descriptor.

        * @since 3.0

        * @param aDes Contains the data that was read. Note that the descriptor

		*        length must be at least aLength!

		* @param aLength How many bytes will be read

        * @return KErrNone, or one of the systemwide error codes.

		*/

		virtual void ReadL( TDes8& aDes, TInt aLength ) = 0;

        /**

        * Reads data from specified position in the source into the specified 8-bit descriptor

        * up to its maximum length.

        * @since 3.0

        * @param aPos Offset from current position

		* @param aDes Contains the data that was read

        * @return KErrNone, or one of the systemwide error codes.

		*/

		virtual void ReadL( TInt aPos, TDes8& aDes ) = 0;

        /**

        * Reads data from specified position in the source into the specified 8-bit descriptor

        * up to its maximum length.

        * @since 3.0

        * @param aPos Offset from current position

		* @param aDes Contains the data that was read

		* @param aLength How many bytes will be read

        * @return KErrNone, or one of the systemwide error codes.

		*/

		virtual void ReadL( TInt aPos, TDes8& aDes, TInt aLength ) = 0;

        /**

        * Returns the size of the source in bytes.

        * @since 3.0

        * @param aSize On return, the size is stored here.

        * @return KErrNone, or one of the systemwide error codes.

		*/

		virtual TInt Size( TInt& aSize ) const = 0;

	};

#endif      // CMETADATASOURCE_H

// End of File