lib/plug-ins.h

   1 /* Dia -- an diagram creation/manipulation program
   2  * Copyright (C) 1999 Alexander Larsson
   3  *
   4  * plug-ins.h: plugin loading handling interfaces for dia
   5  * Copyright (C) 2000 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 #ifndef PLUG_INS_H
  23 #define PLUG_INS_H
  24
  25 #include <glib.h>
  26 #include <gmodule.h>
  27 #include "diatypes.h"
  28
  29 /*
  30  * The api version to ensure dia core and the plug-ins agree on
  31  * talking about the same thing. If some incompatible change is
  32  * made to the interface between plug-ins and core it needs to
  33  * be incremented to allow the core to detect outdated plug-ins
  34  * and avoid to load them - which otherwise would produce strange
  35  * misinterpretations or even crashes.
  36  *
  37  * Some of the things which require a new plug-in api version are :
  38  *  - Changes to DiaRenderer's vtable, that is adding new methods,
  39  *    especially if they are shifting the placement of previously
  40  *    defined ones, see : lib/diarenderer.h
  41  *  - Changes to lib/object.h:_ObjectOps
  42  *  - Changes to _DiaExportFilter, _DiaImportFilter, lib/filter.h
  43  *  - New, incompatibe versions of libraries where both the core
  44  *    and the plug-in depend on (Dia >0.90 crashing on pygtk 1.x
  45  *    could have been avoided this way)
  46  * The list is by no means complete. If in doubt about your change
  47  * please ask on dia-list or alternative increment ;-)      --hb
  48  */
  49 #define DIA_PLUGIN_API_VERSION 6
  50
  51 typedef enum {
  52   DIA_PLUGIN_INIT_OK,
  53   DIA_PLUGIN_INIT_ERROR
  54 } PluginInitResult;
  55
  56 typedef PluginInitResult (*PluginInitFunc) (PluginInfo *info);
  57 typedef gboolean (*PluginCanUnloadFunc) (PluginInfo *info);
  58 typedef void (*PluginUnloadFunc) (PluginInfo *info);
  59
  60 /* functions for use by plugins ... */
  61
  62 gboolean dia_plugin_info_init(PluginInfo *info, gchar *name,
  63                               gchar *description,
  64                               PluginCanUnloadFunc can_unload_func,
  65                               PluginUnloadFunc unload_func);
  66
  67 gchar *dia_plugin_check_version(gint version);
  68
  69
  70 /* functiosn for use by dia ... */
  71 const gchar *dia_plugin_get_filename    (PluginInfo *info);
  72 const gchar *dia_plugin_get_name        (PluginInfo *info);
  73 const gchar *dia_plugin_get_description (PluginInfo *info);
  74 const gpointer *dia_plugin_get_symbol   (PluginInfo *info, const gchar *name);
  75
  76 gboolean dia_plugin_can_unload       (PluginInfo *info);
  77 gboolean dia_plugin_is_loaded        (PluginInfo *info);
  78 gboolean dia_plugin_get_inhibit_load (PluginInfo *info);
  79 void     dia_plugin_set_inhibit_load (PluginInfo *info, gboolean inhibit_load);
  80
  81 void dia_plugin_load   (PluginInfo *info);
  82 void dia_plugin_unload (PluginInfo *info);
  83
  84 void dia_register_plugin         (const gchar *filename);
  85 void dia_register_plugins_in_dir (const gchar *directory);
  86 void dia_register_plugins        (void);
  87 void dia_register_builtin_plugin (PluginInitFunc init_func);
  88
  89 GList *dia_list_plugins(void);
  90
  91 void dia_pluginrc_write(void);
  92
  93 /* macro defining the version check that should be implemented by all
  94  * plugins. */
  95 #define DIA_PLUGIN_CHECK_INIT \
  96 G_MODULE_EXPORT const gchar *g_module_check_init(GModule *gmodule); \
  97 const gchar * \
  98 g_module_check_init(GModule *gmodule) \
  99 { \
 100   return dia_plugin_check_version(DIA_PLUGIN_API_VERSION); \
 101 }
 102
 103 /* prototype for plugin init function (should be implemented by plugin) */
 104 G_MODULE_EXPORT PluginInitResult dia_plugin_init(PluginInfo *info);
 105
 106 #endif