gio/gmenuexporter.c

   1 /*
   2  * Copyright © 2011 Canonical Ltd.
   3  *
   4  *  This library is free software; you can redistribute it and/or
   5  *  modify it under the terms of the GNU Lesser General Public
   6  *  License as published by the Free Software Foundation; either
   7  *  version 2.1 of the License, or (at your option) any later version.
   8  *
   9  *  This library is distributed in the hope that it will be useful, but
  10  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  *  Lesser General Public License for more details.
  13  *
  14  *  You should have received a copy of the GNU Lesser General Public
  15  *  License along with this library; if not, see <http://www.gnu.org/licenses/>.
  16  *
  17  * Author: Ryan Lortie <desrt@desrt.ca>
  18  */
  19
  20 #include "config.h"
  21
  22 #include "gmenuexporter.h"
  23
  24 #include "gdbusmethodinvocation.h"
  25 #include "gdbusintrospection.h"
  26 #include "gdbusnamewatching.h"
  27 #include "gdbuserror.h"
  28
  29 /**
  30  * SECTION:gmenuexporter
  31  * @title: GMenuModel exporter
  32  * @short_description: Export GMenuModels on D-Bus
  33  * @include: gio/gio.h
  34  * @see_also: #GMenuModel, #GDBusMenuModel
  35  *
  36  * These functions support exporting a #GMenuModel on D-Bus.
  37  * The D-Bus interface that is used is a private implementation
  38  * detail.
  39  *
  40  * To access an exported #GMenuModel remotely, use
  41  * g_dbus_menu_model_get() to obtain a #GDBusMenuModel.
  42  */
  43
  44 /* {{{1 D-Bus Interface description */
  45
  46 /* For documentation of this interface, see
  47  * https://wiki.gnome.org/Projects/GLib/GApplication/DBusAPI
  48  */
  49
  50 static GDBusInterfaceInfo *
  51 org_gtk_Menus_get_interface (void)
  52 {
  53   static GDBusInterfaceInfo *interface_info;
  54
  55   if (interface_info == NULL)
  56     {
  57       GError *error = NULL;
  58       GDBusNodeInfo *info;
  59
  60       info = g_dbus_node_info_new_for_xml ("<node>"
  61                                            "  <interface name='org.gtk.Menus'>"
  62                                            "    <method name='Start'>"
  63                                            "      <arg type='au' name='groups' direction='in'/>"
  64                                            "      <arg type='a(uuaa{sv})' name='content' direction='out'/>"
  65                                            "    </method>"
  66                                            "    <method name='End'>"
  67                                            "      <arg type='au' name='groups' direction='in'/>"
  68                                            "    </method>"
  69                                            "    <signal name='Changed'>"
  70                                            "      arg type='a(uuuuaa{sv})' name='changes'/>"
  71                                            "    </signal>"
  72                                            "  </interface>"
  73                                            "</node>", &error);
  74       if (info == NULL)
  75         g_error ("%s\n", error->message);
  76       interface_info = g_dbus_node_info_lookup_interface (info, "org.gtk.Menus");
  77       g_assert (interface_info != NULL);
  78       g_dbus_interface_info_ref (interface_info);
  79       g_dbus_node_info_unref (info);
  80     }
  81
  82   return interface_info;
  83 }
  84
  85 /* {{{1 Forward declarations */
  86 typedef struct _GMenuExporterMenu                           GMenuExporterMenu;
  87 typedef struct _GMenuExporterLink                           GMenuExporterLink;
  88 typedef struct _GMenuExporterGroup                          GMenuExporterGroup;
  89 typedef struct _GMenuExporterRemote                         GMenuExporterRemote;
  90 typedef struct _GMenuExporterWatch                          GMenuExporterWatch;
  91 typedef struct _GMenuExporter                               GMenuExporter;
  92
  93 static gboolean                 g_menu_exporter_group_is_subscribed    (GMenuExporterGroup *group);
  94 static guint                    g_menu_exporter_group_get_id           (GMenuExporterGroup *group);
  95 static GMenuExporter *          g_menu_exporter_group_get_exporter     (GMenuExporterGroup *group);
  96 static GMenuExporterMenu *      g_menu_exporter_group_add_menu         (GMenuExporterGroup *group,
  97                                                                         GMenuModel         *model);
  98 static void                     g_menu_exporter_group_remove_menu      (GMenuExporterGroup *group,
  99                                                                         guint               id);
 100
 101 static GMenuExporterGroup *     g_menu_exporter_create_group           (GMenuExporter      *exporter);
 102 static GMenuExporterGroup *     g_menu_exporter_lookup_group           (GMenuExporter      *exporter,
 103                                                                         guint               group_id);
 104 static void                     g_menu_exporter_report                 (GMenuExporter      *exporter,
 105                                                                         GVariant           *report);
 106 static void                     g_menu_exporter_remove_group           (GMenuExporter      *exporter,
 107                                                                         guint               id);
 108
 109 /* {{{1 GMenuExporterLink, GMenuExporterMenu */
 110
 111 struct _GMenuExporterMenu
 112 {
 113   GMenuExporterGroup *group;
 114   guint               id;
 115
 116   GMenuModel *model;
 117   gulong      handler_id;
 118   GSequence  *item_links;
 119 };
 120
 121 struct _GMenuExporterLink
 122 {
 123   gchar             *name;
 124   GMenuExporterMenu *menu;
 125   GMenuExporterLink *next;
 126 };
 127
 128 static void
 129 g_menu_exporter_menu_free (GMenuExporterMenu *menu)
 130 {
 131   g_menu_exporter_group_remove_menu (menu->group, menu->id);
 132
 133   if (menu->handler_id != 0)
 134     g_signal_handler_disconnect (menu->model, menu->handler_id);
 135
 136   if (menu->item_links != NULL)
 137     g_sequence_free (menu->item_links);
 138
 139   g_object_unref (menu->model);
 140
 141   g_slice_free (GMenuExporterMenu, menu);
 142 }
 143
 144 static void
 145 g_menu_exporter_link_free (gpointer data)
 146 {
 147   GMenuExporterLink *link = data;
 148
 149   while (link != NULL)
 150     {
 151       GMenuExporterLink *tmp = link;
 152       link = tmp->next;
 153
 154       g_menu_exporter_menu_free (tmp->menu);
 155       g_free (tmp->name);
 156
 157       g_slice_free (GMenuExporterLink, tmp);
 158     }
 159 }
 160
 161 static GMenuExporterLink *
 162 g_menu_exporter_menu_create_links (GMenuExporterMenu *menu,
 163                                    gint               position)
 164 {
 165   GMenuExporterLink *list = NULL;
 166   GMenuLinkIter *iter;
 167   const char *name;
 168   GMenuModel *model;
 169
 170   iter = g_menu_model_iterate_item_links (menu->model, position);
 171
 172   while (g_menu_link_iter_get_next (iter, &name, &model))
 173     {
 174       GMenuExporterGroup *group;
 175       GMenuExporterLink *tmp;
 176
 177       /* keep sections in the same group, but create new groups
 178        * otherwise
 179        */
 180       if (!g_str_equal (name, "section"))
 181         group = g_menu_exporter_create_group (g_menu_exporter_group_get_exporter (menu->group));
 182       else
 183         group = menu->group;
 184
 185       tmp = g_slice_new (GMenuExporterLink);
 186       tmp->name = g_strconcat (":", name, NULL);
 187       tmp->menu = g_menu_exporter_group_add_menu (group, model);
 188       tmp->next = list;
 189       list = tmp;
 190
 191       g_object_unref (model);
 192     }
 193
 194   g_object_unref (iter);
 195
 196   return list;
 197 }
 198
 199 static GVariant *
 200 g_menu_exporter_menu_describe_item (GMenuExporterMenu *menu,
 201                                     gint               position)
 202 {
 203   GMenuAttributeIter *attr_iter;
 204   GVariantBuilder builder;
 205   GSequenceIter *iter;
 206   GMenuExporterLink *link;
 207   const char *name;
 208   GVariant *value;
 209
 210   g_variant_builder_init (&builder, G_VARIANT_TYPE_VARDICT);
 211
 212   attr_iter = g_menu_model_iterate_item_attributes (menu->model, position);
 213   while (g_menu_attribute_iter_get_next (attr_iter, &name, &value))
 214     {
 215       g_variant_builder_add (&builder, "{sv}", name, value);
 216       g_variant_unref (value);
 217     }
 218   g_object_unref (attr_iter);
 219
 220   iter = g_sequence_get_iter_at_pos (menu->item_links, position);
 221   for (link = g_sequence_get (iter); link; link = link->next)
 222     g_variant_builder_add (&builder, "{sv}", link->name,
 223                            g_variant_new ("(uu)", g_menu_exporter_group_get_id (link->menu->group), link->menu->id));
 224
 225   return g_variant_builder_end (&builder);
 226 }
 227
 228 static GVariant *
 229 g_menu_exporter_menu_list (GMenuExporterMenu *menu)
 230 {
 231   GVariantBuilder builder;
 232   gint i, n;
 233
 234   g_variant_builder_init (&builder, G_VARIANT_TYPE ("aa{sv}"));
 235
 236   n = g_sequence_get_length (menu->item_links);
 237   for (i = 0; i < n; i++)
 238     g_variant_builder_add_value (&builder, g_menu_exporter_menu_describe_item (menu, i));
 239
 240   return g_variant_builder_end (&builder);
 241 }
 242
 243 static void
 244 g_menu_exporter_menu_items_changed (GMenuModel *model,
 245                                     gint        position,
 246                                     gint        removed,
 247                                     gint        added,
 248                                     gpointer    user_data)
 249 {
 250   GMenuExporterMenu *menu = user_data;
 251   GSequenceIter *point;
 252   gint i;
 253
 254   g_assert (menu->model == model);
 255   g_assert (menu->item_links != NULL);
 256   g_assert (position + removed <= g_sequence_get_length (menu->item_links));
 257
 258   point = g_sequence_get_iter_at_pos (menu->item_links, position + removed);
 259   g_sequence_remove_range (g_sequence_get_iter_at_pos (menu->item_links, position), point);
 260
 261   for (i = position; i < position + added; i++)
 262     g_sequence_insert_before (point, g_menu_exporter_menu_create_links (menu, i));
 263
 264   if (g_menu_exporter_group_is_subscribed (menu->group))
 265     {
 266       GVariantBuilder builder;
 267
 268       g_variant_builder_init (&builder, G_VARIANT_TYPE ("(uuuuaa{sv})"));
 269       g_variant_builder_add (&builder, "u", g_menu_exporter_group_get_id (menu->group));
 270       g_variant_builder_add (&builder, "u", menu->id);
 271       g_variant_builder_add (&builder, "u", position);
 272       g_variant_builder_add (&builder, "u", removed);
 273
 274       g_variant_builder_open (&builder, G_VARIANT_TYPE ("aa{sv}"));
 275       for (i = position; i < position + added; i++)
 276         g_variant_builder_add_value (&builder, g_menu_exporter_menu_describe_item (menu, i));
 277       g_variant_builder_close (&builder);
 278
 279       g_menu_exporter_report (g_menu_exporter_group_get_exporter (menu->group), g_variant_builder_end (&builder));
 280     }
 281 }
 282
 283 static void
 284 g_menu_exporter_menu_prepare (GMenuExporterMenu *menu)
 285 {
 286   gint n_items;
 287
 288   g_assert (menu->item_links == NULL);
 289
 290   if (g_menu_model_is_mutable (menu->model))
 291     menu->handler_id = g_signal_connect (menu->model, "items-changed",
 292                                          G_CALLBACK (g_menu_exporter_menu_items_changed), menu);
 293
 294   menu->item_links = g_sequence_new (g_menu_exporter_link_free);
 295
 296   n_items = g_menu_model_get_n_items (menu->model);
 297   if (n_items)
 298     g_menu_exporter_menu_items_changed (menu->model, 0, 0, n_items, menu);
 299 }
 300
 301 static GMenuExporterMenu *
 302 g_menu_exporter_menu_new (GMenuExporterGroup *group,
 303                           guint               id,
 304                           GMenuModel         *model)
 305 {
 306   GMenuExporterMenu *menu;
 307
 308   menu = g_slice_new0 (GMenuExporterMenu);
 309   menu->group = group;
 310   menu->id = id;
 311   menu->model = g_object_ref (model);
 312
 313   return menu;
 314 }
 315
 316 /* {{{1 GMenuExporterGroup */
 317
 318 struct _GMenuExporterGroup
 319 {
 320   GMenuExporter *exporter;
 321   guint          id;
 322
 323   GHashTable *menus;
 324   guint       next_menu_id;
 325   gboolean    prepared;
 326
 327   gint subscribed;
 328 };
 329
 330 static void
 331 g_menu_exporter_group_check_if_useless (GMenuExporterGroup *group)
 332 {
 333   if (g_hash_table_size (group->menus) == 0 && group->subscribed == 0)
 334     {
 335       g_menu_exporter_remove_group (group->exporter, group->id);
 336
 337       g_hash_table_unref (group->menus);
 338
 339       g_slice_free (GMenuExporterGroup, group);
 340     }
 341 }
 342
 343 static void
 344 g_menu_exporter_group_subscribe (GMenuExporterGroup *group,
 345                                  GVariantBuilder    *builder)
 346 {
 347   GHashTableIter iter;
 348   gpointer key, val;
 349
 350   if (!group->prepared)
 351     {
 352       GMenuExporterMenu *menu;
 353
 354       /* set this first, so that any menus created during the
 355        * preparation of the first menu also end up in the prepared
 356        * state.
 357        * */
 358       group->prepared = TRUE;
 359
 360       menu = g_hash_table_lookup (group->menus, 0);
 361
 362       /* If the group was created by a subscription and does not yet
 363        * exist, it won't have a root menu...
 364        *
 365        * That menu will be prepared if it is ever added (due to
 366        * group->prepared == TRUE).
 367        */
 368       if (menu)
 369         g_menu_exporter_menu_prepare (menu);
 370     }
 371
 372   group->subscribed++;
 373
 374   g_hash_table_iter_init (&iter, group->menus);
 375   while (g_hash_table_iter_next (&iter, &key, &val))
 376     {
 377       guint id = GPOINTER_TO_INT (key);
 378       GMenuExporterMenu *menu = val;
 379
 380       if (!g_sequence_is_empty (menu->item_links))
 381         {
 382           g_variant_builder_open (builder, G_VARIANT_TYPE ("(uuaa{sv})"));
 383           g_variant_builder_add (builder, "u", group->id);
 384           g_variant_builder_add (builder, "u", id);
 385           g_variant_builder_add_value (builder, g_menu_exporter_menu_list (menu));
 386           g_variant_builder_close (builder);
 387         }
 388     }
 389 }
 390
 391 static void
 392 g_menu_exporter_group_unsubscribe (GMenuExporterGroup *group,
 393                                    gint                count)
 394 {
 395   g_assert (group->subscribed >= count);
 396
 397   group->subscribed -= count;
 398
 399   g_menu_exporter_group_check_if_useless (group);
 400 }
 401
 402 static GMenuExporter *
 403 g_menu_exporter_group_get_exporter (GMenuExporterGroup *group)
 404 {
 405   return group->exporter;
 406 }
 407
 408 static gboolean
 409 g_menu_exporter_group_is_subscribed (GMenuExporterGroup *group)
 410 {
 411   return group->subscribed > 0;
 412 }
 413
 414 static guint
 415 g_menu_exporter_group_get_id (GMenuExporterGroup *group)
 416 {
 417   return group->id;
 418 }
 419
 420 static void
 421 g_menu_exporter_group_remove_menu (GMenuExporterGroup *group,
 422                                    guint               id)
 423 {
 424   g_hash_table_remove (group->menus, GINT_TO_POINTER (id));
 425
 426   g_menu_exporter_group_check_if_useless (group);
 427 }
 428
 429 static GMenuExporterMenu *
 430 g_menu_exporter_group_add_menu (GMenuExporterGroup *group,
 431                                 GMenuModel         *model)
 432 {
 433   GMenuExporterMenu *menu;
 434   guint id;
 435
 436   id = group->next_menu_id++;
 437   menu = g_menu_exporter_menu_new (group, id, model);
 438   g_hash_table_insert (group->menus, GINT_TO_POINTER (id), menu);
 439
 440   if (group->prepared)
 441     g_menu_exporter_menu_prepare (menu);
 442
 443   return menu;
 444 }
 445
 446 static GMenuExporterGroup *
 447 g_menu_exporter_group_new (GMenuExporter *exporter,
 448                            guint          id)
 449 {
 450   GMenuExporterGroup *group;
 451
 452   group = g_slice_new0 (GMenuExporterGroup);
 453   group->menus = g_hash_table_new (NULL, NULL);
 454   group->exporter = exporter;
 455   group->id = id;
 456
 457   return group;
 458 }
 459
 460 /* {{{1 GMenuExporterRemote */
 461
 462 struct _GMenuExporterRemote
 463 {
 464   GMenuExporter *exporter;
 465   GHashTable    *watches;
 466   guint          watch_id;
 467 };
 468
 469 static void
 470 g_menu_exporter_remote_subscribe (GMenuExporterRemote *remote,
 471                                   guint                group_id,
 472                                   GVariantBuilder     *builder)
 473 {
 474   GMenuExporterGroup *group;
 475   guint count;
 476
 477   count = (gsize) g_hash_table_lookup (remote->watches, GINT_TO_POINTER (group_id));
 478   g_hash_table_insert (remote->watches, GINT_TO_POINTER (group_id), GINT_TO_POINTER (count + 1));
 479
 480   /* Group will be created (as empty/unsubscribed if it does not exist) */
 481   group = g_menu_exporter_lookup_group (remote->exporter, group_id);
 482   g_menu_exporter_group_subscribe (group, builder);
 483 }
 484
 485 static void
 486 g_menu_exporter_remote_unsubscribe (GMenuExporterRemote *remote,
 487                                     guint                group_id)
 488 {
 489   GMenuExporterGroup *group;
 490   guint count;
 491
 492   count = (gsize) g_hash_table_lookup (remote->watches, GINT_TO_POINTER (group_id));
 493
 494   if (count == 0)
 495     return;
 496
 497   if (count != 1)
 498     g_hash_table_insert (remote->watches, GINT_TO_POINTER (group_id), GINT_TO_POINTER (count - 1));
 499   else
 500     g_hash_table_remove (remote->watches, GINT_TO_POINTER (group_id));
 501
 502   group = g_menu_exporter_lookup_group (remote->exporter, group_id);
 503   g_menu_exporter_group_unsubscribe (group, 1);
 504 }
 505
 506 static gboolean
 507 g_menu_exporter_remote_has_subscriptions (GMenuExporterRemote *remote)
 508 {
 509   return g_hash_table_size (remote->watches) != 0;
 510 }
 511
 512 static void
 513 g_menu_exporter_remote_free (gpointer data)
 514 {
 515   GMenuExporterRemote *remote = data;
 516   GHashTableIter iter;
 517   gpointer key, val;
 518
 519   g_hash_table_iter_init (&iter, remote->watches);
 520   while (g_hash_table_iter_next (&iter, &key, &val))
 521     {
 522       GMenuExporterGroup *group;
 523
 524       group = g_menu_exporter_lookup_group (remote->exporter, GPOINTER_TO_INT (key));
 525       g_menu_exporter_group_unsubscribe (group, GPOINTER_TO_INT (val));
 526     }
 527
 528   if (remote->watch_id > 0)
 529     g_bus_unwatch_name (remote->watch_id);
 530
 531   g_hash_table_unref (remote->watches);
 532
 533   g_slice_free (GMenuExporterRemote, remote);
 534 }
 535
 536 static GMenuExporterRemote *
 537 g_menu_exporter_remote_new (GMenuExporter *exporter,
 538                             guint          watch_id)
 539 {
 540   GMenuExporterRemote *remote;
 541
 542   remote = g_slice_new0 (GMenuExporterRemote);
 543   remote->exporter = exporter;
 544   remote->watches = g_hash_table_new (NULL, NULL);
 545   remote->watch_id = watch_id;
 546
 547   return remote;
 548 }
 549
 550 /* {{{1 GMenuExporter */
 551
 552 struct _GMenuExporter
 553 {
 554   GDBusConnection *connection;
 555   gchar *object_path;
 556   guint registration_id;
 557   GHashTable *groups;
 558   guint next_group_id;
 559
 560   GMenuExporterMenu *root;
 561   GMenuExporterRemote *peer_remote;
 562   GHashTable *remotes;
 563 };
 564
 565 static void
 566 g_menu_exporter_name_vanished (GDBusConnection *connection,
 567                                const gchar     *name,
 568                                gpointer         user_data)
 569 {
 570   GMenuExporter *exporter = user_data;
 571
 572   /* connection == NULL when we get called because the connection closed */
 573   g_assert (exporter->connection == connection || connection == NULL);
 574
 575   g_hash_table_remove (exporter->remotes, name);
 576 }
 577
 578 static GVariant *
 579 g_menu_exporter_subscribe (GMenuExporter *exporter,
 580                            const gchar   *sender,
 581                            GVariant      *group_ids)
 582 {
 583   GMenuExporterRemote *remote;
 584   GVariantBuilder builder;
 585   GVariantIter iter;
 586   guint32 id;
 587
 588   if (sender != NULL)
 589     remote = g_hash_table_lookup (exporter->remotes, sender);
 590   else
 591     remote = exporter->peer_remote;
 592
 593   if (remote == NULL)
 594     {
 595       if (sender != NULL)
 596         {
 597           guint watch_id;
 598
 599           watch_id = g_bus_watch_name_on_connection (exporter->connection, sender, G_BUS_NAME_WATCHER_FLAGS_NONE,
 600                                                      NULL, g_menu_exporter_name_vanished, exporter, NULL);
 601           remote = g_menu_exporter_remote_new (exporter, watch_id);
 602           g_hash_table_insert (exporter->remotes, g_strdup (sender), remote);
 603         }
 604       else
 605         remote = exporter->peer_remote =
 606           g_menu_exporter_remote_new (exporter, 0);
 607     }
 608
 609   g_variant_builder_init (&builder, G_VARIANT_TYPE ("(a(uuaa{sv}))"));
 610
 611   g_variant_builder_open (&builder, G_VARIANT_TYPE ("a(uuaa{sv})"));
 612
 613   g_variant_iter_init (&iter, group_ids);
 614   while (g_variant_iter_next (&iter, "u", &id))
 615     g_menu_exporter_remote_subscribe (remote, id, &builder);
 616
 617   g_variant_builder_close (&builder);
 618
 619   return g_variant_builder_end (&builder);
 620 }
 621
 622 static void
 623 g_menu_exporter_unsubscribe (GMenuExporter *exporter,
 624                              const gchar   *sender,
 625                              GVariant      *group_ids)
 626 {
 627   GMenuExporterRemote *remote;
 628   GVariantIter iter;
 629   guint32 id;
 630
 631   if (sender != NULL)
 632     remote = g_hash_table_lookup (exporter->remotes, sender);
 633   else
 634     remote = exporter->peer_remote;
 635
 636   if (remote == NULL)
 637     return;
 638
 639   g_variant_iter_init (&iter, group_ids);
 640   while (g_variant_iter_next (&iter, "u", &id))
 641     g_menu_exporter_remote_unsubscribe (remote, id);
 642
 643   if (!g_menu_exporter_remote_has_subscriptions (remote))
 644     {
 645       if (sender != NULL)
 646         g_hash_table_remove (exporter->remotes, sender);
 647       else
 648         g_clear_pointer (&exporter->peer_remote, g_menu_exporter_remote_free);
 649     }
 650 }
 651
 652 static void
 653 g_menu_exporter_report (GMenuExporter *exporter,
 654                         GVariant      *report)
 655 {
 656   GVariantBuilder builder;
 657
 658   g_variant_builder_init (&builder, G_VARIANT_TYPE_TUPLE);
 659   g_variant_builder_open (&builder, G_VARIANT_TYPE_ARRAY);
 660   g_variant_builder_add_value (&builder, report);
 661   g_variant_builder_close (&builder);
 662
 663   g_dbus_connection_emit_signal (exporter->connection,
 664                                  NULL,
 665                                  exporter->object_path,
 666                                  "org.gtk.Menus", "Changed",
 667                                  g_variant_builder_end (&builder),
 668                                  NULL);
 669 }
 670
 671 static void
 672 g_menu_exporter_remove_group (GMenuExporter *exporter,
 673                               guint          id)
 674 {
 675   g_hash_table_remove (exporter->groups, GINT_TO_POINTER (id));
 676 }
 677
 678 static GMenuExporterGroup *
 679 g_menu_exporter_lookup_group (GMenuExporter *exporter,
 680                               guint          group_id)
 681 {
 682   GMenuExporterGroup *group;
 683
 684   group = g_hash_table_lookup (exporter->groups, GINT_TO_POINTER (group_id));
 685
 686   if (group == NULL)
 687     {
 688       group = g_menu_exporter_group_new (exporter, group_id);
 689       g_hash_table_insert (exporter->groups, GINT_TO_POINTER (group_id), group);
 690     }
 691
 692   return group;
 693 }
 694
 695 static GMenuExporterGroup *
 696 g_menu_exporter_create_group (GMenuExporter *exporter)
 697 {
 698   GMenuExporterGroup *group;
 699   guint id;
 700
 701   id = exporter->next_group_id++;
 702   group = g_menu_exporter_group_new (exporter, id);
 703   g_hash_table_insert (exporter->groups, GINT_TO_POINTER (id), group);
 704
 705   return group;
 706 }
 707
 708 static void
 709 g_menu_exporter_free (gpointer user_data)
 710 {
 711   GMenuExporter *exporter = user_data;
 712
 713   g_menu_exporter_menu_free (exporter->root);
 714   g_clear_pointer (&exporter->peer_remote, g_menu_exporter_remote_free);
 715   g_hash_table_unref (exporter->remotes);
 716   g_hash_table_unref (exporter->groups);
 717   g_object_unref (exporter->connection);
 718   g_free (exporter->object_path);
 719
 720   g_slice_free (GMenuExporter, exporter);
 721 }
 722
 723 static void
 724 g_menu_exporter_method_call (GDBusConnection       *connection,
 725                              const gchar           *sender,
 726                              const gchar           *object_path,
 727                              const gchar           *interface_name,
 728                              const gchar           *method_name,
 729                              GVariant              *parameters,
 730                              GDBusMethodInvocation *invocation,
 731                              gpointer               user_data)
 732 {
 733   GMenuExporter *exporter = user_data;
 734   GVariant *group_ids;
 735
 736   group_ids = g_variant_get_child_value (parameters, 0);
 737
 738   if (g_str_equal (method_name, "Start"))
 739     g_dbus_method_invocation_return_value (invocation, g_menu_exporter_subscribe (exporter, sender, group_ids));
 740
 741   else if (g_str_equal (method_name, "End"))
 742     {
 743       g_menu_exporter_unsubscribe (exporter, sender, group_ids);
 744       g_dbus_method_invocation_return_value (invocation, NULL);
 745     }
 746
 747   else
 748     g_assert_not_reached ();
 749
 750   g_variant_unref (group_ids);
 751 }
 752
 753 /* {{{1 Public API */
 754
 755 /**
 756  * g_dbus_connection_export_menu_model:
 757  * @connection: a #GDBusConnection
 758  * @object_path: a D-Bus object path
 759  * @menu: a #GMenuModel
 760  * @error: return location for an error, or %NULL
 761  *
 762  * Exports @menu on @connection at @object_path.
 763  *
 764  * The implemented D-Bus API should be considered private.
 765  * It is subject to change in the future.
 766  *
 767  * An object path can only have one menu model exported on it. If this
 768  * constraint is violated, the export will fail and 0 will be
 769  * returned (with @error set accordingly).
 770  *
 771  * You can unexport the menu model using
 772  * g_dbus_connection_unexport_menu_model() with the return value of
 773  * this function.
 774  *
 775  * Returns: the ID of the export (never zero), or 0 in case of failure
 776  *
 777  * Since: 2.32
 778  */
 779 guint
 780 g_dbus_connection_export_menu_model (GDBusConnection  *connection,
 781                                      const gchar      *object_path,
 782                                      GMenuModel       *menu,
 783                                      GError          **error)
 784 {
 785   const GDBusInterfaceVTable vtable = {
 786     g_menu_exporter_method_call,
 787   };
 788   GMenuExporter *exporter;
 789   guint id;
 790
 791   exporter = g_slice_new0 (GMenuExporter);
 792
 793   id = g_dbus_connection_register_object (connection, object_path, org_gtk_Menus_get_interface (),
 794                                           &vtable, exporter, g_menu_exporter_free, error);
 795
 796   if (id == 0)
 797     {
 798       g_slice_free (GMenuExporter, exporter);
 799       return 0;
 800     }
 801
 802   exporter->connection = g_object_ref (connection);
 803   exporter->object_path = g_strdup (object_path);
 804   exporter->groups = g_hash_table_new (NULL, NULL);
 805   exporter->remotes = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, g_menu_exporter_remote_free);
 806   exporter->root = g_menu_exporter_group_add_menu (g_menu_exporter_create_group (exporter), menu);
 807
 808   return id;
 809 }
 810
 811 /**
 812  * g_dbus_connection_unexport_menu_model:
 813  * @connection: a #GDBusConnection
 814  * @export_id: the ID from g_dbus_connection_export_menu_model()
 815  *
 816  * Reverses the effect of a previous call to
 817  * g_dbus_connection_export_menu_model().
 818  *
 819  * It is an error to call this function with an ID that wasn't returned
 820  * from g_dbus_connection_export_menu_model() or to call it with the
 821  * same ID more than once.
 822  *
 823  * Since: 2.32
 824  */
 825 void
 826 g_dbus_connection_unexport_menu_model (GDBusConnection *connection,
 827                                        guint            export_id)
 828 {
 829   g_dbus_connection_unregister_object (connection, export_id);
 830 }
 831
 832 /* {{{1 Epilogue */
 833 /* vim:set foldmethod=marker: */