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 G_BEGIN_DECLS
  30
  31 /*
  32  * The api version to ensure dia core and the plug-ins agree on
  33  * talking about the same thing. If some incompatible change is
  34  * made to the interface between plug-ins and core it needs to
  35  * be incremented to allow the core to detect outdated plug-ins
  36  * and avoid to load them - which otherwise would produce strange
  37  * misinterpretations or even crashes.
  38  *
  39  * Some of the things which require a new plug-in api version are :
  40  *  - Changes to DiaRenderer's vtable, that is adding new methods,
  41  *    especially if they are shifting the placement of previously
  42  *    defined ones, see : lib/diarenderer.h
  43  *  - Changes to lib/object.h:_ObjectOps
  44  *  - Changes to _DiaExportFilter, _DiaImportFilter, lib/filter.h
  45  *  - New, incompatibe versions of libraries where both the core
  46  *    and the plug-in depend on (Dia >0.90 crashing on pygtk 1.x
  47  *    could have been avoided this way)
  48  * The list is by no means complete. If in doubt about your change
  49  * please ask on dia-list or alternative increment ;-)      --hb
  50  */
  51 #define DIA_PLUGIN_API_VERSION 7
  52
  53 typedef enum {
  54   DIA_PLUGIN_INIT_OK,
  55   DIA_PLUGIN_INIT_ERROR
  56 } PluginInitResult;
  57
  58 typedef PluginInitResult (*PluginInitFunc) (PluginInfo *info);
  59 typedef gboolean (*PluginCanUnloadFunc) (PluginInfo *info);
  60 typedef void (*PluginUnloadFunc) (PluginInfo *info);
  61
  62 /* functions for use by plugins ... */
  63
  64 gboolean dia_plugin_info_init(PluginInfo *info, gchar *name,
  65                               gchar *description,
  66                               PluginCanUnloadFunc can_unload_func,
  67                               PluginUnloadFunc unload_func);
  68
  69 gchar *dia_plugin_check_version(gint version);
  70
  71
  72 /* functiosn for use by dia ... */
  73 const gchar *dia_plugin_get_filename    (PluginInfo *info);
  74 const gchar *dia_plugin_get_name        (PluginInfo *info);
  75 const gchar *dia_plugin_get_description (PluginInfo *info);
  76 const gpointer *dia_plugin_get_symbol   (PluginInfo *info, const gchar *name);
  77
  78 gboolean dia_plugin_can_unload       (PluginInfo *info);
  79 gboolean dia_plugin_is_loaded        (PluginInfo *info);
  80 gboolean dia_plugin_get_inhibit_load (PluginInfo *info);
  81 void     dia_plugin_set_inhibit_load (PluginInfo *info, gboolean inhibit_load);
  82
  83 void dia_plugin_load   (PluginInfo *info);
  84 void dia_plugin_unload (PluginInfo *info);
  85
  86 void dia_register_plugin         (const gchar *filename);
  87 void dia_register_plugins_in_dir (const gchar *directory);
  88 void dia_register_plugins        (void);
  89 void dia_register_builtin_plugin (PluginInitFunc init_func);
  90
  91 GList *dia_list_plugins(void);
  92
  93 void dia_pluginrc_write(void);
  94
  95 /* macro defining the version check that should be implemented by all
  96  * plugins. */
  97 #define DIA_PLUGIN_CHECK_INIT \
  98 G_MODULE_EXPORT const gchar *g_module_check_init(GModule *gmodule); \
  99 const gchar * \
 100 g_module_check_init(GModule *gmodule) \
 101 { \
 102   return dia_plugin_check_version(DIA_PLUGIN_API_VERSION); \
 103 }
 104
 105 /* prototype for plugin init function (should be implemented by plugin) */
 106 G_MODULE_EXPORT PluginInitResult dia_plugin_init(PluginInfo *info);
 107
 108 G_END_DECLS
 109
 110 #endif