/*

* Copyright (c) 2003, 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:  Exif data parser for both Little and Big Endian formats.

*

*/

#ifndef EXIFENDIAN_H

#define EXIFENDIAN_H

//  INCLUDES

#include <e32base.h>

// CLASS DECLARATION

/**

*  Exif data parser base class.

*  Provides the base for Little and Big endian parsers.

*

*  @lib ExifLib

*  @since 2.6 

*/

NONSHARABLE_CLASS( CExifEndianBase ): public CBase

    {

    public:  // Constructors and destructor

        /**

        * Two-phased constructor.

        */

        static CExifEndianBase* NewBaseL( 

            const TUint8* aExifDataPtr, 

            TUint aDataLength, 

            TBool aIsExif );

        /**

        * Destructor.

        */

        virtual ~CExifEndianBase();

        /**

        * Gets the next 8-bit unsigned integer from the data.

        * @since 2.6 

        * @param aUint8 The 8-bit integer returned.

        * @return Error code.

        */

        TInt ReadUint8( TUint8& aUint8 );

        /**

        * Gets the next 16-bit unsigned integer from the data.

        * @since 2.6 

        * @param aUint16 The 16-bit integer returned.

        * @return Error code.

        */

        virtual TInt ReadUInt16( TUint16& aUint16 ) = 0;

        /**

        * Gets the next 32-bit unsigned integer from the data.

        * @since 2.6 

        * @param aUint32 The 32-bit integer returned.

        * @return Error code.

        */

        virtual TInt ReadUInt32( TUint32& aUint32 ) = 0;

        /**

        * Copies the data from the location, which starts and ends with the 

        * given Jpeg Markers.

        * @since 2.6 

        * @param aStartMarker Jpeg Marker for the beginning of copying.

        * @param aEndMarker Jpeg Marker for the end of copying.

        * @param aDestBuffer Pointer to the target descriptor.

        * @param aIncludeEnd States if the ending Jpeg Marker will be copied 

        *                    or not.

        * @return void

        */

        void CopyBufferL( 

            TUint16 aStartMarker, 

            TUint16 aEndMarker, 

            HBufC8*& aDestBuffer, 

            TBool aIncludeEnd = ETrue );

        /**

        * Copies the next specified amount of data to the given descriptor.

        * @since 2.6 

        * @param aCount Number of words to copy

        * @param aWordSize Word size

        * @param aBuffer Pointer to the target descriptor.

        * @return void

        */

        virtual TInt CopyBuffer( 

            TUint32 aCount, 

            TUint8 aWordSize, 

            HBufC8*& aBuffer ) = 0;

        /**

        * Copies the specified amount of data located in the given offset to 

        * the given descriptor.

        * @since 2.6 

        * @param aOffset Offset for starting copying

        * @param aCount Number of words to copy

        * @param aWordSize Word size

        * @param aBuffer Pointer to the target descriptor.

        * @return void

        */

        virtual TInt CopyBuffer( 

            TUint32 aOffset, 

            TUint32 aCount, 

            TUint8 aWordSize, 

            HBufC8*& aBuffer ) = 0;

        /**

        * Moves to the specified offset.

        * @since 2.6 

        * @param aOffset Target offset.

        * @return Error code.

        */

        TInt MoveTo( TUint aOffset );

        /**

        * Moves the current position forward by the given number of bytes.

        * @since 2.6 

        * @param aNoBytes Number of bytes to skip

        * @return Error code.

        */

        TInt Skip( TUint aNoBytes );

        /**

        * Locates the offset of the next specified 8-bit unsigned integer 

        * @since 2.6 

        * @param aSearch Queried 8-bit unsigned integer

        * @param aOffset The offset of the found location.

        * @return Error code.

        */

        TInt Locate8( TUint8 aSearch, TUint32& aOffset );

        /**

        * Locates the offset of the next specified 16-bit unsigned integer 

        * @since 2.6 

        * @param aSearch Queried 16-bit integer

        * @param aOffset The offset of the found location.

        * @return Error code.

        */

        virtual TInt Locate16( TUint16 aSearch, TUint32& aOffset ) = 0;

        /**

        * Locates the offset of the specified Jpeg Marker, which resides 

        * inside the given interval.

        * @since 2.6 

        * @param aMarker The queried Jpeg Marker

        * @param aOffset The offset of the found location.

        * @param aAfter Offset for starting searching.

        * @param aBefore Offset for ending searching.

        * @return Error code.

        */

        TInt LocateJpegMarker( 

            TUint16 aMarker, 

            TUint32& aOffset, 

            TUint32 aAfter = 0,

            TUint32 aBefore = 0 );

        /**

        * Locates the offset of the last specified Jpeg Marker, which resides

        * inside the given interval

        * @since 2.6 

        * @param aMarker The queried Jpeg Marker

        * @param aOffset The offset of the found location.

        * @param aAfter Offset for starting searching.

        * @param aBefore Offset for ending searching.

        * @return Error code.

        */

        TInt LocateJpegMarkerFromEnd( 

            TUint16 aMarker, 

            TUint32& aOffset, 

            TUint32 aAfter = 0,

            TUint32 aBefore = 0 );

        /**

        * Returns the current offset position

        * @since 3.1 

        * @param aOffset The offset of the location.

        * @return void.

        */

        void CurrentPosOffset( TUint32& aOffset );

    protected:

        /**

        * C++ default constructor.

        */

        CExifEndianBase();

    private:

        /**

        * By default Symbian 2nd phase constructor is private.

        */

        void ConstructL();

    protected:  // Data

        // The offset of the current position in the Exif data.

        TUint32 iPosOffset;

        // The offset of the Exif header (APP1 header) in the Exif data.

        TUint32 iExifStartOffset;

        // The offset for the end of Exif data.

        TUint32 iExifEndOffset;

        // The pointer to the beginning of the Exif data.

        TUint8* iDataStartPtr;

    };

/**

*  Exif data parser class for Little endian format.

*

*  @lib ExifLib

*  @since 2.6 

*/

NONSHARABLE_CLASS( CExifLittleEndian ): public CExifEndianBase

    {

    public:  // Constructors and destructor

        /**

        * Two-phased constructor.

        */

        static CExifLittleEndian* NewL( 

            const TUint8* aDataStartPtr,

            TUint8* aExifStartPtr, 

            TUint8* aExifEndPtr, 

            TBool aIsExif );

        /**

        * C++ default constructor.

        */

        CExifLittleEndian();

        /**

        * Destructor.

        */        

        virtual ~CExifLittleEndian();

    public: // Functions from base classes

        /**

        * From CExifEndianBase Gets the next 16-bit unsigned integer from the 

        * data.

        * @since 2.6 

        * @param aUint16 The 16-bit integer returned.

        * @return Error code.

        */

        TInt ReadUInt16( TUint16& aUint16 );

        /**

        * From CExifEndianBase Gets the next 32-bit unsigned integer from the 

        * data.

        * @since 2.6 

        * @param aUint32 The 32-bit integer returned.

        * @return Error code.

        */        

        TInt ReadUInt32( TUint32& aUint32 );

        /**

        * From CExifEndianBase Copies the next specified amount of data to the 

        * given descriptor.

        * @since 2.6 

        * @param aCount Number of words to copy

        * @param aWordSize Word size

        * @param aBuffer Pointer to the target descriptor.

        * @return void

        */

        TInt CopyBuffer( TUint32 aCount, TUint8 aWordSize, HBufC8*& aBuffer );

        /**

        * From CExifEndianBase Copies the specified amount of data located in 

        * the given offset to the given descriptor.

        * @since 2.6 

        * @param aOffset Offset for starting copying

        * @param aCount Number of words to copy

        * @param aWordSize Word size

        * @param aBuffer Pointer to the target descriptor.

        * @return void

        */

        TInt CopyBuffer( 

            TUint32 aOffset, 

            TUint32 aCount, 

            TUint8 aWordSize, 

            HBufC8*& aBuffer );

        /**

        * From CExifEndianBase Locates the offset of the next specified 16-bit 

        * unsigned integer 

        * @since 2.6 

        * @param aSearch Queried 16-bit integer

        * @param aOffset The offset of the found location.

        * @return Error code.

        */        

        TInt Locate16( TUint16 aSearch, TUint32& aOffset );

    private:

        /**

        * By default Symbian 2nd phase constructor is private.

        */

        void ConstructL( 

            TUint8* aDataStartPtr,

            TUint8* aExifStartPtr, 

            TUint8* aExifEndPtr, 

            TBool aIsExif );

    };

/**

*  Exif data parser class for Big endian format.

*

*  @lib ExifLib

*  @since 2.6 

*/

NONSHARABLE_CLASS( CExifBigEndian ): public CExifEndianBase

    {

    public:

        /**

        * Two-phased constructor.

        */

        static CExifBigEndian* NewL( 

            const TUint8* aDataStartPtr, 

            TUint8* aExifStartPtr, 

            TUint8* aExifEndPtr, 

            TBool aIsExif );

        /**

        * C++ default constructor.

        */

        CExifBigEndian();

        /**

        * Destructor.

        */        

        virtual ~CExifBigEndian();

    public: // Functions from base classes

        /**

        * From CExifEndianBase Gets the next 16-bit unsigned integer from the 

        * data.

        * @since 2.6 

        * @param aUint16 The 16-bit integer returned.

        * @return Error code.

        */        

        TInt ReadUInt16( TUint16& aUint16 );

        /**

        * From CExifEndianBase Gets the next 32-bit unsigned integer from the 

        * data.

        * @since 2.6 

        * @param aUint32 The 32-bit integer returned.

        * @return Error code.

        */        

        TInt ReadUInt32( TUint32& aUint32 );

        /**

        * From CExifEndianBase Copies the next specified amount of data to the 

        * given descriptor.

        * @since 2.6 

        * @param aCount Number of words to copy

        * @param aWordSize Word size

        * @param aBuffer Pointer to the target descriptor.

        * @return void

        */

        TInt CopyBuffer( TUint32 aCount, TUint8 aWordSize, HBufC8*& aBuffer );

        /**

        * From CExifEndianBase Copies the specified amount of data located in 

        * the given offset to the given descriptor.

        * @since 2.6 

        * @param aOffset Offset for starting copying

        * @param aCount Number of words to copy

        * @param aWordSize Word size

        * @param aBuffer Pointer to the target descriptor.

        * @return void

        */

        TInt CopyBuffer( 

            TUint32 aOffset, 

            TUint32 aCount, 

            TUint8 aWordSize, 

            HBufC8*& aBuffer );

        /**

        * From CExifEndianBase Locates the offset of the next specified 16-bit 

        * unsigned integer 

        * @since 2.6 

        * @param aSearch Queried 16-bit integer

        * @param aOffset The offset of the found location.

        * @return Error code.

        */        

        TInt Locate16( TUint16 aSearch, TUint32& aOffset );

    private:

        /**

        * By default Symbian 2nd phase constructor is private.

        */

        void ConstructL( 

            TUint8* aDataStartPtr, 

            TUint8* aExifStartPtr, 

            TUint8* aExifEndPtr, 

            TBool aIsExif );

    };

#endif // EXIFENDIAN_H

// End of File