/* 
   elmo - ELectronic Mail Operator

   Copyright (C) 2003 rzyjontko

   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; version 2.

   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.  

   ----------------------------------------------------------------------
   
   An implementation of hooks.
   
*/
/****************************************************************************
 *    IMPLEMENTATION HEADERS
 ****************************************************************************/

#include "hook.h"
#include "xmalloc.h"

/****************************************************************************
 *    IMPLEMENTATION PRIVATE DEFINITIONS / ENUMERATIONS / SIMPLE TYPEDEFS
 ****************************************************************************/
/****************************************************************************
 *    IMPLEMENTATION PRIVATE CLASS PROTOTYPES / EXTERNAL CLASS REFERENCES
 ****************************************************************************/
/****************************************************************************
 *    IMPLEMENTATION PRIVATE STRUCTURES / UTILITY CLASSES
 ****************************************************************************/
/****************************************************************************
 *    IMPLEMENTATION REQUIRED EXTERNAL REFERENCES (AVOID)
 ****************************************************************************/
/****************************************************************************
 *    IMPLEMENTATION PRIVATE DATA
 ****************************************************************************/
/****************************************************************************
 *    INTERFACE DATA
 ****************************************************************************/
/****************************************************************************
 *    IMPLEMENTATION PRIVATE FUNCTION PROTOTYPES
 ****************************************************************************/
/****************************************************************************
 *    IMPLEMENTATION PRIVATE FUNCTIONS
 ****************************************************************************/
/****************************************************************************
 *    INTERFACE FUNCTIONS
 ****************************************************************************/


hook_t *
hook_create (void (*action)(void))
{
  hook_t *result = xmalloc (sizeof (hook_t));
  result->action = action;
  result->next   = NULL;
  return result;
}


void
hook_add (hook_t *hook, void (*action)(void))
{
  if (hook->action == NULL){
    hook->action = action;
  }
  else {
    while (hook->next)
      hook = hook->next;
    hook->next = hook_create (action);
  }
}


void
hook_destroy (hook_t *hook)
{
  hook_t *tmp;

  if (hook == NULL)
    return;
  
  hook = hook->next;
  while (hook){
    tmp = hook->next;
    xfree (hook);
    hook = tmp;
  }
}


void
hook_execute (hook_t *hook)
{
  while (hook){
    if (hook->action)
      hook->action ();
    hook = hook->next;
  }
}

/****************************************************************************
 *    INTERFACE CLASS BODIES
 ****************************************************************************/
/****************************************************************************
 *
 *    END MODULE hook.c
 *
 ****************************************************************************/