/*
 * Program name:  shim
 * Version:	  1.1 beta
 * Source file:	  shim_func.h (function prototypes, included in shim.c)
 * Description:	  A simple command line utility to show graphical images
 *		  of various formats. Use <shim -h> for more information.
 *
 * Comments:	  In general functions return -1 on failure and 0 on success.
 *
 * Copyright (C) 2005-2007  Jeroen van Aart
 *
 * This program 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.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

/*
 * holds data used in multiple functions
 */
struct Shim_Data
{
  SDL_Surface *screen; /* main surface */
  SDL_Surface *image; /* will hold the image to be displayed */
  char *name; /* the name of the image file to be loaded */
  int fullscreen; /* if 0 then display in window, if 1 then display fullscreen */
  int slideshow; /* if 0 then no slideshow, if 1 then slideshow, decided by option -s */
  int always; /* if 0 then do not continue forever with slideshow, if 1 then do so, decided by option -a in combination with -s */
  int sec; /* amount of seconds between image displays in slideshow mode */
  int msec; /* amount of miliseconds calculated from amount of seconds */
  int angle; /* holds the angle of rotation, 0=no rotation, 90, 270 */
  double zoom; /* if set to 0.5 image will be zoomed to half size, if 2 it will be zoomed to double size */
  int smooth; /* if set to 1 anti-aliasing is used with zooming/rotating */
  int output; /* if set to 1 images will be saved to a file instead of displayed */
};

/* 
  graciously exit the program 
*/
void cleanened
(
  struct Shim_Data *shimdata
);

/* 
  calls checkevent inside a loop 
*/
void eventloop
(
  struct Shim_Data *shimdata
);

/*
  shows an image, returns -1 on failure and 0 on success
*/
int showimage
(
  struct Shim_Data *shimdata,
  char *name
);

/* 
  shows an image when the -s option(slideshow) has been used 
*/
void showimage_slide
(
  struct Shim_Data *shimdata,
  int argc,
  char **argv
);

/*
 * shos an image possibly zoomed and/or rotated
 * return 0 on success, -1 on failure
 */
int showimage_zoom
(
  struct Shim_Data *shimdata,
  double zoom,
  int angle
);

/* 
  process the arguments given at program startup, if any  
*/
void process_arguments
(
  struct Shim_Data *shimdata,
  int arg,
  char **argv
);

/* 
  handles the -h(help) argument 
*/
void print_help
(
  char *name
);

/* 
  when program is started without any arguments this will print a short help text 
*/
void print_shorthelp
(
  char *name
);

/*
  during msec amount of time this function repeatedely calls checkevent_poll 
  and then waits for a while using delay, used with -s option(slideshow)
*/
void do_delay
(
  struct Shim_Data *shimdata,
  int msec
);

/* 
  show version information when -v option(version) has been given 
*/
void do_version
(
  void
);

/* 
  check the arguments given with the -s option(slideshow) 
*/
int process_s
(
  int argc,
  char **argv
);

/*
  Checks if the given string has only numeric values or not,
  returns -1 if string contains more than just numeric values, else 0
*/
int checkifnum
(
  int l,
  char **argv
);

/* 
  setup and prepare SDL for usage 
*/
int setupsdl
(
  void
);

/* 
  waits for an event to happen and acts accordingly 
*/
int checkevent
(
  struct Shim_Data *shimdata
);

/* 
  polls for an event which may have happened and acts accordingly
*/
int checkevent_poll
(
  struct Shim_Data *shimdata
);