src/mm-module.c

   1 /* MManager - a Desktop wide manager for multimedia applications.
   2  *
   3  * Copyright (C) 2008 Cosimo Cecchi <cosimoc@gnome.org>
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, write to the
  17  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18  * Boston, MA 02111-1307, USA.
  19  */
  20
  21 #include <glib.h>
  22 #include <glib-object.h>
  23 #include <gmodule.h>
  24 #include "mm-application-provider.h"
  25 #include "mm-category-provider.h"
  26 #include "mm-hit-collection-provider.h"
  27 #include "mm-module.h"
  28
  29 #define MM_MODULE_GET_PRIVATE(o) \
  30    (G_TYPE_INSTANCE_GET_PRIVATE ((o), MM_TYPE_MODULE, MMModuleDetails))
  31
  32 G_DEFINE_TYPE (MMModule, mm_module, G_TYPE_TYPE_MODULE);
  33
  34 struct _MMModuleDetails {
  35   /* library objects */
  36   char    *filename;
  37   GModule *library;
  38
  39   /* providers implemented by the module */
  40   MMApplicationProvider   *app_provider;
  41   MMCategoryProvider      *category_provider;
  42   MMHitCollectionProvider *collection_provider;
  43 };
  44
  45
  46 static gboolean mm_module_load (GTypeModule *gtm);
  47 static void mm_module_unload (GTypeModule *gtm);
  48
  49 static void
  50 mm_module_finalize (GObject *o)
  51 {
  52   MMModule *module = MM_MODULE (o);
  53
  54   g_free (module->details->filename);
  55   G_OBJECT_CLASS (mm_module_parent_class)->finalize (o);
  56 }
  57
  58 static void
  59 mm_module_class_init (MMModuleClass *klass)
  60 {
  61   GTypeModuleClass *type_module_class = G_TYPE_MODULE_CLASS (klass);
  62
  63   type_module_class->load = mm_module_load;
  64   type_module_class->unload = mm_module_unload;
  65   G_OBJECT_CLASS (klass)->finalize = mm_module_finalize;
  66
  67   g_type_class_add_private (klass, sizeof (MMModuleDetails));
  68 }
  69
  70 static void
  71 mm_module_init (MMModule *module)
  72 {
  73   MMModuleDetails *details =  module->details = MM_MODULE_GET_PRIVATE (module);
  74
  75   details->filename = NULL;
  76   details->library = NULL;
  77 }
  78
  79 static gboolean
  80 mm_module_load (GTypeModule *gtm)
  81 {
  82   MMModule *module = MM_MODULE (gtm);
  83   MMModuleDetails *details = module->details;
  84   gpointer m_initialize, m_shutdown, m_get_types;
  85
  86   details->library = g_module_open (details->filename,
  87                                     G_MODULE_BIND_LAZY |
  88                                     G_MODULE_BIND_LOCAL);
  89   if (!details->library) {
  90     g_warning ("error while loading module %s: %s",
  91                details->filename, g_module_error ());
  92     return FALSE;
  93   }
  94
  95   if (!g_module_symbol (details->library,
  96                         "mm_module_initialize",
  97                         &m_initialize) ||
  98       !g_module_symbol (details->library,
  99                         "mm_module_shutdown",
 100                         &m_shutdown) ||
 101       !g_module_symbol (details->library,
 102                         "mm_module_get_types",
 103                         &m_get_types)) {
 104     g_warning ("Unable to resolve symbols inside the module %s: %s",
 105                details->filename, g_module_error ());
 106     g_module_close (details->library);
 107
 108     return FALSE;
 109   }
 110
 111   module->initialize = m_initialize;
 112   module->shutdown = m_shutdown;
 113   module->get_types = m_get_types;
 114
 115   module->initialize (gtm);
 116
 117   return TRUE;
 118 }
 119
 120 static void
 121 mm_module_unload (GTypeModule *gtm)
 122 {
 123         MMModule *module = MM_MODULE (gtm);
 124
 125   module->shutdown ();
 126
 127   g_module_close (module->details->library);
 128
 129   module->initialize = NULL;
 130   module->shutdown = NULL;
 131   module->get_types = NULL;
 132 }
 133
 134 static GObject *
 135 mm_module_create_provider (MMModule *module, GType type)
 136 {
 137   return g_object_new (type, NULL);
 138 }
 139
 140 static void
 141 mm_module_add_types (MMModule *module, GType *types)
 142 {
 143   /* types[0] implements MMApplicationProvider
 144    * types[1] implements MMCategoryProvider
 145    * types[2] implements MMHitCollectionProvider
 146    */
 147   MMModuleDetails *details = module->details;
 148
 149   details->app_provider =
 150     MM_APPLICATION_PROVIDER (mm_module_create_provider (module, types[0]));
 151   details->category_provider =
 152     MM_CATEGORY_PROVIDER (mm_module_create_provider (module, types[1]));
 153   details->collection_provider =
 154     MM_HIT_COLLECTION_PROVIDER (mm_module_create_provider (module, types[2]));
 155 }
 156
 157 static void
 158 add_module_objects (MMModule *module)
 159 {
 160   GType *gtypes;
 161
 162   module->get_types (&gtypes);
 163
 164   mm_module_add_types (module, gtypes);
 165 }
 166
 167 /* public methods */
 168
 169 MMModule *
 170 mm_module_load_file (const char *path)
 171 {
 172   MMModule *module;
 173
 174   module = g_object_new (MM_TYPE_MODULE, NULL);
 175   module->details->filename = g_strdup (path);
 176
 177   if (g_type_module_use (G_TYPE_MODULE (module))) {
 178     add_module_objects (module);
 179     g_type_module_unuse (G_TYPE_MODULE (module));
 180     return module;
 181   } else {
 182     g_object_unref (module);
 183     return NULL;
 184   }
 185 }
 186
 187 MMApplicationProvider *
 188 mm_module_get_application_provider (MMModule *m)
 189 {
 190   g_return_val_if_fail (m != NULL, NULL);
 191
 192   return m->details->app_provider;
 193 }
 194
 195 MMCategoryProvider *
 196 mm_module_get_category_provider (MMModule *m)
 197 {
 198   g_return_val_if_fail (m != NULL, NULL);
 199
 200   return m->details->category_provider;
 201 }
 202
 203 MMHitCollectionProvider *
 204 mm_module_get_hit_collection_provider (MMModule *m)
 205 {
 206   g_return_val_if_fail (m != NULL, NULL);
 207
 208   return m->details->collection_provider;
 209 }