Application: gvSIG desktop

/* $Id: lt_ioCallbackStream.h 3539 2006-01-09 12:23:20Z nacho $ */

/* //////////////////////////////////////////////////////////////////////////

//                                                                         //

// This code is Copyright (c) 2004 LizardTech, Inc, 1008 Western Avenue,   //

// Suite 200, Seattle, WA 98104.  Unauthorized use or distribution         //

// prohibited.  Access to and use of this code is permitted only under     //

// license from LizardTech, Inc.  Portions of the code are protected by    //

// US and foreign patents and other filings. All Rights Reserved.          //

//                                                                         //

////////////////////////////////////////////////////////////////////////// */

/* PUBLIC */

#ifndef LT_IO_CALLBACK_STREAM_H

#define LT_IO_CALLBACK_STREAM_H

#include "lt_ioCallbackStreamTypes.h"

#include "lt_ioStreamInf.h"

#if defined(LT_COMPILER_MS)

        #pragma warning(push,4)

#endif

LT_BEGIN_NAMESPACE( LizardTech )

/**

 * Stream driven entirely by user-defined callbacks

 *

 * This class implements a stream whose operations -- read(), write(), open(),

 * close(), etc -- are all defined by functions passed in from the user.

 *

 * This class can be used as an alternative to deriving custom stream classes

 * from LTIOStreamInf.  This class also forms the basis for the C-callable

 * stream defined in lt_ioCStream.h.

 */

class LTIOCallbackStream : public LTIOStreamInf

{

public:

   LTIOCallbackStream();

   virtual ~LTIOCallbackStream();

   /**

    * initialize

    *

    * The parameters to this function are a set of function pointers

    * which implement all the required operations needed to support

    * a stream.  Their semantics exactly mirror the semantics of the

    * corresponding member functions in LTIOStreamInf.

    *

    * The \a user parameter is a pointer to a user-defined area

    * containing information about the stream itself, e.g. the

    * filename and a FILE*.  This pointer is passed as the first

    * argument to each of the user's stream functions.  This class

    * never attempts to interpret this data directly.

    *

    * Note that the implementation of the \a duplicate function

    * is required to create a new copy of this user-defined data by

    * whatever means appropriate.  The user retains ownership of the

    * copied user data.

    *

    * @param  open       pointer to user's open function

    * @param  close      pointer to user's close function

    * @param  read       pointer to user's read function

    * @param  write      pointer to user's write function

    * @param  seek       pointer to user's seek function

    * @param  tell       pointer to user's tell function

    * @param  isEOF      pointer to user's isEOF function

    * @param  isOpen     pointer to user's isOpen function

    * @param  duplicate  pointer to user's duplicate function

    * @param  user       pointer to user-defined stream data

    * @return status code indicating success or failure

    */

   virtual LT_STATUS initialize(LTIOCallbackStream_Open open,

                                LTIOCallbackStream_Close close,

                                LTIOCallbackStream_Read read,

                                LTIOCallbackStream_Write write,

                                LTIOCallbackStream_Seek seek,

                                LTIOCallbackStream_Tell tell,

                                LTIOCallbackStream_IsEOF isEOF,

                                LTIOCallbackStream_IsOpen isOpen,

                                LTIOCallbackStream_Duplicate duplicate,

                                void* user);

        virtual bool isEOF();

        virtual bool isOpen();

   virtual LT_STATUS open();

        virtual LT_STATUS close();

   virtual lt_uint32 read( lt_uint8 *pDest, lt_uint32 numBytes );

   virtual lt_uint32 write( const lt_uint8 *pSrc, lt_uint32 numBytes );

   virtual LT_STATUS seek( lt_int64 offset, LTIOSeekDir origin );

   virtual lt_int64 tell();

   virtual LTIOStreamInf* duplicate();

        virtual LT_STATUS getLastError() const;

        virtual const char* getID() const;

private:

   LTIOCallbackStream_Open m_open;

   LTIOCallbackStream_Close m_close;

   LTIOCallbackStream_Read m_read;

   LTIOCallbackStream_Write m_write;

   LTIOCallbackStream_Seek m_seek;

   LTIOCallbackStream_Tell m_tell;

   LTIOCallbackStream_IsEOF m_isEOF;

   LTIOCallbackStream_IsOpen m_isOpen;

   LTIOCallbackStream_Duplicate m_duplicate;

   void* m_user;

};

LT_END_NAMESPACE( LizardTech )

#if defined(LT_COMPILER_MS)

        #pragma warning(pop)

#endif

#endif // LT_IO_CALLBACK_STREAM_H