sane-project-backends/include/sane/sanei.h

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/* sane - Scanner Access Now Easy.
Copyright (C) 1996 David Mosberger-Tang and Andreas Beck
This file is part of the SANE package.
SANE is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
SANE is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
License for more details.
You should have received a copy of the GNU General Public License
along with sane; see the file COPYING. If not, write to the Free
Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/** @file sanei.h
* Convenience macros and function declarations for backends
* @sa sanei_backend.h sanei_thread.h
*/
/* Doxygen documentation */
/** @mainpage SANEI (SANE internal routines) documentation
*
* @image html ../sane-logo2.jpg
* @section intro Introduction
*
* The header files in the include/sane/ directory named sanei_*.h provide
* function declarations and macros that can be used by every SANE backend.
* Their implementations can be found in the sanei/ directory. The code aims
* to be platform-independent to avoid lots of \#ifdef code in the backends.
* Please use the SANEI functions wherever possible.
*
* This documentation was created by the use of doxygen, the
* doc/doxygen-sanei.conf configuration file and dcoumentation in the sanei_*.h
* files.
*
* This documenation is far from complete. Any help is appreciated.
*
* @section additional Additional documentation
* - The SANE standard can be found at <a
* href="http://www.mostang.com/sane/html/">the SANE webserver</a>.
* - Information on how to write a backend: <a
* href="../backend-writing.txt">backend-writing.txt</a>.
* - General SANE documentation is on <a
* href="http://www.mostang.com/sane/docs.html>the SANE documentation
* page</a>.
*
* @section contact Contact
*
* The common way to contact the developers of SANE is the sane-devel
* mailing list. See the <a
* href="http://www.mostang.com/sane/mail.html">mailing list webpage</a>
* for details. That's the place to ask questions, report bugs, or announce
* a new backend.
*
*/
#ifndef sanei_h
#define sanei_h
#include <sane/sane.h>
/** @name Public macros and functions
* @{
*/
/** @def STRINGIFY(x)
* Turn parameter into string.
*/
/** @def PASTE(x,y)
* Concatenate parameters.
*
*/
/** @def NELEMS(a)
* Return number of elements of an array.
*
*/
/** @fn extern SANE_Status sanei_check_value (const SANE_Option_Descriptor * opt, void * value);
* Check the constraints of a SANE option.
*
* @param opt option to check
* @param value value of the option
*
* @return
* - SANE_STATUS_GOOD - on success
* - SANE_STATUS_INVAL - if the value doesn't fit inside the constraint
* or any other error occured
* @sa sanei_constrain_value()
*/
/** @fn extern SANE_Status sanei_constrain_value (const SANE_Option_Descriptor * opt, void * value, SANE_Word * info);
* Check the constraints of a SANE option and adjust its value if necessary.
*
* Depending on the type of the option and constraint, value is modified
* to fit inside constraint.
*
* @param opt option to check
* @param value value of the option
* @param info info is set to SANE_INFO_INEXACT if value was changed
*
* @return
* - SANE_STATUS_GOOD - on success
* - SANE_STATUS_INVAL - if the function wasn't able to fit value into the
* constraint or any other error occured
* @sa sanei_check_value()
*/
/* @} */
/** @name Private macros
* @{
*/
/** @def STRINGIFY1(x)
* Internal use only.
*/
/** @def PASTE1(x,y)
* Internal use only.
*/
/* @} */
/* A few convenience macros: */
/** @hideinitializer */
#define NELEMS(a) ((int)(sizeof (a) / sizeof (a[0])))
/** @hideinitializer */
#define STRINGIFY1(x) #x
/** @hideinitializer */
#define STRINGIFY(x) STRINGIFY1(x)
/** @hideinitializer */
#define PASTE1(x,y) x##y
/** @hideinitializer */
#define PASTE(x,y) PASTE1(x,y)
extern SANE_Status sanei_check_value (const SANE_Option_Descriptor * opt,
void * value);
extern SANE_Status sanei_constrain_value (const SANE_Option_Descriptor * opt,
void * value, SANE_Word * info);
#endif /* sanei_h */