lib/hook.c

   1 /* Hooks
   2    Copyright (C) 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003,
   3    2004, 2005, 2007, 2009, 2010 Free Software Foundation, Inc.
   4    Written 1994, 1995, 1996 by:
   5    Miguel de Icaza, Janne Kukonlehto, Dugan Porter,
   6    Jakub Jelinek, Mauricio Plaza.
   7
   8    The file_date routine is mostly from GNU's fileutils package,
   9    written by Richard Stallman and David MacKenzie.
  10
  11    This program is free software; you can redistribute it and/or modify
  12    it under the terms of the GNU General Public License as published by
  13    the Free Software Foundation; either version 2 of the License, or
  14    (at your option) any later version.
  15
  16    This program is distributed in the hope that it will be useful,
  17    but WITHOUT ANY WARRANTY; without even the implied warranty of
  18    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19    GNU General Public License for more details.
  20
  21    You should have received a copy of the GNU General Public License
  22    along with this program; if not, write to the Free Software
  23    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  24
  25 /** \file
  26  *  \brief Source: hooks
  27  */
  28
  29 #include <config.h>
  30
  31 #include "lib/global.h"
  32 #include "lib/hook.h"
  33
  34 /*** global variables ****************************************************************************/
  35
  36 /*** file scope macro definitions ****************************************************************/
  37
  38 /*** file scope type declarations ****************************************************************/
  39
  40 /*** file scope variables ************************************************************************/
  41
  42 /*** file scope functions ************************************************************************/
  43
  44 /* --------------------------------------------------------------------------------------------- */
  45 /*** public functions ****************************************************************************/
  46 /* --------------------------------------------------------------------------------------------- */
  47
  48 void
  49 add_hook (hook_t ** hook_list, void (*hook_fn) (void *), void *data)
  50 {
  51     hook_t *new_hook = g_new (hook_t, 1);
  52
  53     new_hook->hook_fn = hook_fn;
  54     new_hook->next = *hook_list;
  55     new_hook->hook_data = data;
  56
  57     *hook_list = new_hook;
  58 }
  59
  60 /* --------------------------------------------------------------------------------------------- */
  61
  62 void
  63 execute_hooks (hook_t * hook_list)
  64 {
  65     hook_t *new_hook = NULL;
  66     hook_t *p;
  67
  68     /* We copy the hook list first so tahat we let the hook
  69      * function call delete_hook
  70      */
  71
  72     while (hook_list != NULL)
  73     {
  74         add_hook (&new_hook, hook_list->hook_fn, hook_list->hook_data);
  75         hook_list = hook_list->next;
  76     }
  77     p = new_hook;
  78
  79     while (new_hook != NULL)
  80     {
  81         new_hook->hook_fn (new_hook->hook_data);
  82         new_hook = new_hook->next;
  83     }
  84
  85     for (hook_list = p; hook_list != NULL;)
  86     {
  87         p = hook_list;
  88         hook_list = hook_list->next;
  89         g_free (p);
  90     }
  91 }
  92
  93 /* --------------------------------------------------------------------------------------------- */
  94
  95 void
  96 delete_hook (hook_t ** hook_list, void (*hook_fn) (void *))
  97 {
  98     hook_t *new_list = NULL;
  99     hook_t *current, *next;
 100
 101     for (current = *hook_list; current != NULL; current = next)
 102     {
 103         next = current->next;
 104         if (current->hook_fn == hook_fn)
 105             g_free (current);
 106         else
 107             add_hook (&new_list, current->hook_fn, current->hook_data);
 108     }
 109     *hook_list = new_list;
 110 }
 111
 112 /* --------------------------------------------------------------------------------------------- */
 113
 114 gboolean
 115 hook_present (hook_t * hook_list, void (*hook_fn) (void *))
 116 {
 117     hook_t *p;
 118
 119     for (p = hook_list; p != NULL; p = p->next)
 120         if (p->hook_fn == hook_fn)
 121             return TRUE;
 122     return FALSE;
 123 }
 124
 125 /* --------------------------------------------------------------------------------------------- */