lib/filter.c

   1 /* Dia -- a diagram creation/manipulation program
   2  * Copyright (C) 1998 Alexander Larsson
   3  *
   4  * filter.c: definitions for adding new loaders and export filters.
   5  * Copyright (C) 1999 James Henstridge
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  20  */
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include <config.h>
  24 #endif
  25
  26 #include "filter.h"
  27 #include "intl.h"
  28 #include <string.h>
  29
  30 static GList *export_filters = NULL;
  31 static GList *import_filters = NULL;
  32 static GList *callback_filters = NULL;
  33
  34 static gint
  35 export_filter_compare(gconstpointer a, gconstpointer b)
  36 {
  37   const DiaExportFilter *fa = a, *fb = b;
  38
  39   return g_strcasecmp(_(fa->description), _(fb->description));
  40 }
  41
  42 void
  43 filter_register_export(DiaExportFilter *efilter)
  44 {
  45   if (efilter->description == NULL) {
  46     return;
  47   }
  48   export_filters = g_list_insert_sorted(export_filters, efilter,
  49                                         export_filter_compare);
  50 }
  51
  52 void
  53 filter_unregister_export(DiaExportFilter *efilter)
  54 {
  55   export_filters = g_list_remove(export_filters, efilter);
  56 }
  57
  58 /* returns a sorted list of the export filters. */
  59 GList *
  60 filter_get_export_filters(void)
  61 {
  62   return export_filters;
  63 }
  64
  65 /* creates a nice label for the export filter (must be g_free'd) */
  66 gchar *
  67 filter_get_export_filter_label(DiaExportFilter *efilter)
  68 {
  69   GString *str = g_string_new(_(efilter->description));
  70   gint ext = 0;
  71   gchar *ret;
  72
  73   for (ext = 0; efilter->extensions[ext] != NULL; ext++) {
  74     if (ext == 0)
  75       g_string_append(str, " (*.");
  76     else
  77       g_string_append(str, ", *.");
  78     g_string_append(str, efilter->extensions[ext]);
  79   }
  80   if (ext > 0)
  81     g_string_append(str, ")");
  82   ret = str->str;
  83   g_string_free(str, FALSE);
  84   return ret;
  85 }
  86
  87 /* Guess the filter for a given filename.
  88  * Returns the first filter found that matches the extension on the filename,
  89  * or NULL if none such are found. */
  90 DiaExportFilter *
  91 filter_guess_export_filter(const gchar *filename)
  92 {
  93   GList *tmp;
  94   gchar *ext;
  95
  96   ext = strrchr(filename, '.');
  97   if (ext)
  98     ext++;
  99   else
 100     ext = "";
 101
 102   for (tmp = export_filters; tmp != NULL; tmp = tmp->next) {
 103     DiaExportFilter *ef = tmp->data;
 104     gint i;
 105
 106     for (i = 0; ef->extensions[i] != NULL; i++)
 107       if (!g_strcasecmp(ef->extensions[i], ext))
 108         return ef;
 109   }
 110   return NULL;
 111 }
 112
 113 /** Get an export filter by unique name.
 114  */
 115 DiaExportFilter *
 116 filter_get_by_name(const gchar *name)
 117 {
 118   GList *tmp;
 119   DiaExportFilter *filter = NULL;
 120
 121   for (tmp = export_filters; tmp != NULL; tmp = tmp->next) {
 122     DiaExportFilter *ef = tmp->data;
 123     if (ef->unique_name != NULL) {
 124       if (!g_strcasecmp(ef->unique_name, name)) {
 125         if (filter)
 126           g_warning(_("Multiple export filters with unique name %s"), name);
 127         filter = ef;
 128       }
 129     }
 130   }
 131   return filter;
 132 }
 133
 134 static gint
 135 import_filter_compare(gconstpointer a, gconstpointer b)
 136 {
 137   const DiaImportFilter *fa = a, *fb = b;
 138
 139   return g_strcasecmp(_(fa->description), _(fb->description));
 140 }
 141
 142 void
 143 filter_register_import(DiaImportFilter *ifilter)
 144 {
 145   if (ifilter->description == NULL) {
 146     return;
 147   }
 148   import_filters = g_list_insert_sorted(import_filters, ifilter,
 149                                         import_filter_compare);
 150 }
 151
 152 void
 153 filter_unregister_import(DiaImportFilter *ifilter)
 154 {
 155   import_filters = g_list_remove(import_filters, ifilter);
 156 }
 157
 158 /* returns a sorted list of the export filters. */
 159 GList *
 160 filter_get_import_filters(void)
 161 {
 162   return import_filters;
 163 }
 164
 165 /* creates a nice label for the export filter (must be g_free'd) */
 166 gchar *
 167 filter_get_import_filter_label(DiaImportFilter *ifilter)
 168 {
 169   GString *str = g_string_new(_(ifilter->description));
 170   gint ext = 0;
 171   gchar *ret;
 172
 173   for (ext = 0; ifilter->extensions[ext] != NULL; ext++) {
 174     if (ext == 0)
 175       g_string_append(str, " (*.");
 176     else
 177       g_string_append(str, ", *.");
 178     g_string_append(str, ifilter->extensions[ext]);
 179   }
 180   if (ext > 0)
 181     g_string_append(str, ")");
 182   ret = str->str;
 183   g_string_free(str, FALSE);
 184   return ret;
 185 }
 186
 187 /* guess the filter for a given filename. */
 188 DiaImportFilter *
 189 filter_guess_import_filter(const gchar *filename)
 190 {
 191   GList *tmp;
 192   gchar *ext;
 193
 194   ext = strrchr(filename, '.');
 195   if (ext)
 196     ext++;
 197   else
 198     ext = "";
 199
 200   for (tmp = import_filters; tmp != NULL; tmp = tmp->next) {
 201     DiaImportFilter *efilter = tmp->data;
 202     gint i;
 203
 204     for (i = 0; efilter->extensions[i] != NULL; i++)
 205       if (!g_strcasecmp(efilter->extensions[i], ext))
 206         return efilter;
 207   }
 208   return NULL;
 209 }
 210
 211 /* register a new callback from a plug-in */
 212 void
 213 filter_register_callback(DiaCallbackFilter *cbfilter)
 214 {
 215   /* sanity check */
 216   g_return_if_fail (cbfilter != NULL);
 217   g_return_if_fail (cbfilter->callback != NULL);
 218   g_return_if_fail (cbfilter->menupath != NULL);
 219   g_return_if_fail (cbfilter->description != NULL);
 220   g_return_if_fail (cbfilter->action != NULL);
 221
 222   /* callback_filters is always pointing to the last element */
 223   callback_filters = g_list_append (callback_filters, (gpointer)cbfilter);
 224 }
 225
 226 /* return the registered callbacks list, called once to build menus */
 227 GList *
 228 filter_get_callbacks(void)
 229 {
 230   return g_list_first (callback_filters);
 231 }