(root)/
glib-2.79.0/
gio/
gmenuexporter.c
       1  /*
       2   * Copyright © 2011 Canonical Ltd.
       3   *
       4   * SPDX-License-Identifier: LGPL-2.1-or-later
       5   *
       6   *  This library is free software; you can redistribute it and/or
       7   *  modify it under the terms of the GNU Lesser General Public
       8   *  License as published by the Free Software Foundation; either
       9   *  version 2.1 of the License, or (at your option) any later version.
      10   *
      11   *  This library is distributed in the hope that it will be useful, but
      12   *  WITHOUT ANY WARRANTY; without even the implied warranty of
      13   *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      14   *  Lesser General Public License for more details.
      15   *
      16   *  You should have received a copy of the GNU Lesser General Public
      17   *  License along with this library; if not, see <http://www.gnu.org/licenses/>.
      18   *
      19   * Author: Ryan Lortie <desrt@desrt.ca>
      20   */
      21  
      22  #include "config.h"
      23  
      24  #include "gmenuexporter.h"
      25  
      26  #include "gdbusmethodinvocation.h"
      27  #include "gdbusintrospection.h"
      28  #include "gdbusnamewatching.h"
      29  #include "gdbuserror.h"
      30  
      31  /* {{{1 D-Bus Interface description */
      32  
      33  /* For documentation of this interface, see
      34   * https://wiki.gnome.org/Projects/GLib/GApplication/DBusAPI
      35   */
      36  
      37  static GDBusInterfaceInfo *
      38  org_gtk_Menus_get_interface (void)
      39  {
      40    static GDBusInterfaceInfo *interface_info;
      41    static gsize interface_info_initialized = 0;
      42  
      43    if (g_once_init_enter (&interface_info_initialized))
      44      {
      45        GError *error = NULL;
      46        GDBusNodeInfo *info;
      47  
      48        info = g_dbus_node_info_new_for_xml ("<node>"
      49                                             "  <interface name='org.gtk.Menus'>"
      50                                             "    <method name='Start'>"
      51                                             "      <arg type='au' name='groups' direction='in'/>"
      52                                             "      <arg type='a(uuaa{sv})' name='content' direction='out'/>"
      53                                             "    </method>"
      54                                             "    <method name='End'>"
      55                                             "      <arg type='au' name='groups' direction='in'/>"
      56                                             "    </method>"
      57                                             "    <signal name='Changed'>"
      58                                             "      arg type='a(uuuuaa{sv})' name='changes'/>"
      59                                             "    </signal>"
      60                                             "  </interface>"
      61                                             "</node>", &error);
      62        if (info == NULL)
      63          g_error ("%s", error->message);
      64        interface_info = g_dbus_node_info_lookup_interface (info, "org.gtk.Menus");
      65        g_assert (interface_info != NULL);
      66        g_dbus_interface_info_ref (interface_info);
      67        g_dbus_node_info_unref (info);
      68  
      69        g_once_init_leave (&interface_info_initialized, 1);
      70      }
      71  
      72    return interface_info;
      73  }
      74  
      75  /* {{{1 Forward declarations */
      76  typedef struct _GMenuExporterMenu                           GMenuExporterMenu;
      77  typedef struct _GMenuExporterLink                           GMenuExporterLink;
      78  typedef struct _GMenuExporterGroup                          GMenuExporterGroup;
      79  typedef struct _GMenuExporterRemote                         GMenuExporterRemote;
      80  typedef struct _GMenuExporterWatch                          GMenuExporterWatch;
      81  typedef struct _GMenuExporter                               GMenuExporter;
      82  
      83  static gboolean                 g_menu_exporter_group_is_subscribed    (GMenuExporterGroup *group);
      84  static guint                    g_menu_exporter_group_get_id           (GMenuExporterGroup *group);
      85  static GMenuExporter *          g_menu_exporter_group_get_exporter     (GMenuExporterGroup *group);
      86  static GMenuExporterMenu *      g_menu_exporter_group_add_menu         (GMenuExporterGroup *group,
      87                                                                          GMenuModel         *model);
      88  static void                     g_menu_exporter_group_remove_menu      (GMenuExporterGroup *group,
      89                                                                          guint               id);
      90  
      91  static GMenuExporterGroup *     g_menu_exporter_create_group           (GMenuExporter      *exporter);
      92  static GMenuExporterGroup *     g_menu_exporter_lookup_group           (GMenuExporter      *exporter,
      93                                                                          guint               group_id);
      94  static void                     g_menu_exporter_report                 (GMenuExporter      *exporter,
      95                                                                          GVariant           *report);
      96  static void                     g_menu_exporter_remove_group           (GMenuExporter      *exporter,
      97                                                                          guint               id);
      98  
      99  /* {{{1 GMenuExporterLink, GMenuExporterMenu */
     100  
     101  struct _GMenuExporterMenu
     102  {
     103    GMenuExporterGroup *group;
     104    guint               id;
     105  
     106    GMenuModel *model;
     107    gulong      handler_id;
     108    GSequence  *item_links;
     109  };
     110  
     111  struct _GMenuExporterLink
     112  {
     113    gchar             *name;
     114    GMenuExporterMenu *menu;
     115    GMenuExporterLink *next;
     116  };
     117  
     118  static void
     119  g_menu_exporter_menu_free (GMenuExporterMenu *menu)
     120  {
     121    g_menu_exporter_group_remove_menu (menu->group, menu->id);
     122  
     123    if (menu->handler_id != 0)
     124      g_signal_handler_disconnect (menu->model, menu->handler_id);
     125  
     126    if (menu->item_links != NULL)
     127      g_sequence_free (menu->item_links);
     128  
     129    g_object_unref (menu->model);
     130  
     131    g_slice_free (GMenuExporterMenu, menu);
     132  }
     133  
     134  static void
     135  g_menu_exporter_link_free (gpointer data)
     136  {
     137    GMenuExporterLink *link = data;
     138  
     139    while (link != NULL)
     140      {
     141        GMenuExporterLink *tmp = link;
     142        link = tmp->next;
     143  
     144        g_menu_exporter_menu_free (tmp->menu);
     145        g_free (tmp->name);
     146  
     147        g_slice_free (GMenuExporterLink, tmp);
     148      }
     149  }
     150  
     151  static GMenuExporterLink *
     152  g_menu_exporter_menu_create_links (GMenuExporterMenu *menu,
     153                                     gint               position)
     154  {
     155    GMenuExporterLink *list = NULL;
     156    GMenuLinkIter *iter;
     157    const char *name;
     158    GMenuModel *model;
     159  
     160    iter = g_menu_model_iterate_item_links (menu->model, position);
     161  
     162    while (g_menu_link_iter_get_next (iter, &name, &model))
     163      {
     164        GMenuExporterGroup *group;
     165        GMenuExporterLink *tmp;
     166  
     167        /* keep sections in the same group, but create new groups
     168         * otherwise
     169         */
     170        if (!g_str_equal (name, "section"))
     171          group = g_menu_exporter_create_group (g_menu_exporter_group_get_exporter (menu->group));
     172        else
     173          group = menu->group;
     174  
     175        tmp = g_slice_new (GMenuExporterLink);
     176        tmp->name = g_strconcat (":", name, NULL);
     177        tmp->menu = g_menu_exporter_group_add_menu (group, model);
     178        tmp->next = list;
     179        list = tmp;
     180  
     181        g_object_unref (model);
     182      }
     183  
     184    g_object_unref (iter);
     185  
     186    return list;
     187  }
     188  
     189  static GVariant *
     190  g_menu_exporter_menu_describe_item (GMenuExporterMenu *menu,
     191                                      gint               position)
     192  {
     193    GMenuAttributeIter *attr_iter;
     194    GVariantBuilder builder;
     195    GSequenceIter *iter;
     196    GMenuExporterLink *link;
     197    const char *name;
     198    GVariant *value;
     199  
     200    g_variant_builder_init (&builder, G_VARIANT_TYPE_VARDICT);
     201  
     202    attr_iter = g_menu_model_iterate_item_attributes (menu->model, position);
     203    while (g_menu_attribute_iter_get_next (attr_iter, &name, &value))
     204      {
     205        g_variant_builder_add (&builder, "{sv}", name, value);
     206        g_variant_unref (value);
     207      }
     208    g_object_unref (attr_iter);
     209  
     210    iter = g_sequence_get_iter_at_pos (menu->item_links, position);
     211    for (link = g_sequence_get (iter); link; link = link->next)
     212      g_variant_builder_add (&builder, "{sv}", link->name,
     213                             g_variant_new ("(uu)", g_menu_exporter_group_get_id (link->menu->group), link->menu->id));
     214  
     215    return g_variant_builder_end (&builder);
     216  }
     217  
     218  static GVariant *
     219  g_menu_exporter_menu_list (GMenuExporterMenu *menu)
     220  {
     221    GVariantBuilder builder;
     222    gint i, n;
     223  
     224    g_variant_builder_init (&builder, G_VARIANT_TYPE ("aa{sv}"));
     225  
     226    n = g_sequence_get_length (menu->item_links);
     227    for (i = 0; i < n; i++)
     228      g_variant_builder_add_value (&builder, g_menu_exporter_menu_describe_item (menu, i));
     229  
     230    return g_variant_builder_end (&builder);
     231  }
     232  
     233  static void
     234  g_menu_exporter_menu_items_changed (GMenuModel *model,
     235                                      gint        position,
     236                                      gint        removed,
     237                                      gint        added,
     238                                      gpointer    user_data)
     239  {
     240    GMenuExporterMenu *menu = user_data;
     241    GSequenceIter *point;
     242    gint i;
     243  #ifndef G_DISABLE_ASSERT
     244    gint n_items;
     245  #endif
     246  
     247    g_assert (menu->model == model);
     248    g_assert (menu->item_links != NULL);
     249  
     250  #ifndef G_DISABLE_ASSERT
     251    n_items = g_sequence_get_length (menu->item_links);
     252  #endif
     253    g_assert (position >= 0 && position < G_MENU_EXPORTER_MAX_SECTION_SIZE);
     254    g_assert (removed >= 0 && removed < G_MENU_EXPORTER_MAX_SECTION_SIZE);
     255    g_assert (added < G_MENU_EXPORTER_MAX_SECTION_SIZE);
     256    g_assert (position + removed <= n_items);
     257    g_assert (n_items - removed + added < G_MENU_EXPORTER_MAX_SECTION_SIZE);
     258  
     259    point = g_sequence_get_iter_at_pos (menu->item_links, position + removed);
     260    g_sequence_remove_range (g_sequence_get_iter_at_pos (menu->item_links, position), point);
     261  
     262    for (i = position; i < position + added; i++)
     263      g_sequence_insert_before (point, g_menu_exporter_menu_create_links (menu, i));
     264  
     265    if (g_menu_exporter_group_is_subscribed (menu->group))
     266      {
     267        GVariantBuilder builder;
     268  
     269        g_variant_builder_init (&builder, G_VARIANT_TYPE ("(uuuuaa{sv})"));
     270        g_variant_builder_add (&builder, "u", g_menu_exporter_group_get_id (menu->group));
     271        g_variant_builder_add (&builder, "u", menu->id);
     272        g_variant_builder_add (&builder, "u", position);
     273        g_variant_builder_add (&builder, "u", removed);
     274  
     275        g_variant_builder_open (&builder, G_VARIANT_TYPE ("aa{sv}"));
     276        for (i = position; i < position + added; i++)
     277          g_variant_builder_add_value (&builder, g_menu_exporter_menu_describe_item (menu, i));
     278        g_variant_builder_close (&builder);
     279  
     280        g_menu_exporter_report (g_menu_exporter_group_get_exporter (menu->group), g_variant_builder_end (&builder));
     281      }
     282  }
     283  
     284  static void
     285  g_menu_exporter_menu_prepare (GMenuExporterMenu *menu)
     286  {
     287    gint n_items;
     288  
     289    g_assert (menu->item_links == NULL);
     290  
     291    if (g_menu_model_is_mutable (menu->model))
     292      menu->handler_id = g_signal_connect (menu->model, "items-changed",
     293                                           G_CALLBACK (g_menu_exporter_menu_items_changed), menu);
     294  
     295    menu->item_links = g_sequence_new (g_menu_exporter_link_free);
     296  
     297    n_items = g_menu_model_get_n_items (menu->model);
     298    if (n_items)
     299      g_menu_exporter_menu_items_changed (menu->model, 0, 0, n_items, menu);
     300  }
     301  
     302  static GMenuExporterMenu *
     303  g_menu_exporter_menu_new (GMenuExporterGroup *group,
     304                            guint               id,
     305                            GMenuModel         *model)
     306  {
     307    GMenuExporterMenu *menu;
     308  
     309    menu = g_slice_new0 (GMenuExporterMenu);
     310    menu->group = group;
     311    menu->id = id;
     312    menu->model = g_object_ref (model);
     313  
     314    return menu;
     315  }
     316  
     317  /* {{{1 GMenuExporterGroup */
     318  
     319  struct _GMenuExporterGroup
     320  {
     321    GMenuExporter *exporter;
     322    guint          id;
     323  
     324    GHashTable *menus;
     325    guint       next_menu_id;
     326    gboolean    prepared;
     327  
     328    gint subscribed;
     329  };
     330  
     331  static void
     332  g_menu_exporter_group_check_if_useless (GMenuExporterGroup *group)
     333  {
     334    if (g_hash_table_size (group->menus) == 0 && group->subscribed == 0)
     335      {
     336        g_menu_exporter_remove_group (group->exporter, group->id);
     337  
     338        g_hash_table_unref (group->menus);
     339  
     340        g_slice_free (GMenuExporterGroup, group);
     341      }
     342  }
     343  
     344  static void
     345  g_menu_exporter_group_subscribe (GMenuExporterGroup *group,
     346                                   GVariantBuilder    *builder)
     347  {
     348    GHashTableIter iter;
     349    gpointer key, val;
     350  
     351    if (!group->prepared)
     352      {
     353        GMenuExporterMenu *menu;
     354  
     355        /* set this first, so that any menus created during the
     356         * preparation of the first menu also end up in the prepared
     357         * state.
     358         * */
     359        group->prepared = TRUE;
     360  
     361        menu = g_hash_table_lookup (group->menus, 0);
     362  
     363        /* If the group was created by a subscription and does not yet
     364         * exist, it won't have a root menu...
     365         *
     366         * That menu will be prepared if it is ever added (due to
     367         * group->prepared == TRUE).
     368         */
     369        if (menu)
     370          g_menu_exporter_menu_prepare (menu);
     371      }
     372  
     373    group->subscribed++;
     374  
     375    g_hash_table_iter_init (&iter, group->menus);
     376    while (g_hash_table_iter_next (&iter, &key, &val))
     377      {
     378        guint id = GPOINTER_TO_INT (key);
     379        GMenuExporterMenu *menu = val;
     380  
     381        if (!g_sequence_is_empty (menu->item_links))
     382          {
     383            g_variant_builder_open (builder, G_VARIANT_TYPE ("(uuaa{sv})"));
     384            g_variant_builder_add (builder, "u", group->id);
     385            g_variant_builder_add (builder, "u", id);
     386            g_variant_builder_add_value (builder, g_menu_exporter_menu_list (menu));
     387            g_variant_builder_close (builder);
     388          }
     389      }
     390  }
     391  
     392  static void
     393  g_menu_exporter_group_unsubscribe (GMenuExporterGroup *group,
     394                                     gint                count)
     395  {
     396    g_assert (group->subscribed >= count);
     397  
     398    group->subscribed -= count;
     399  
     400    g_menu_exporter_group_check_if_useless (group);
     401  }
     402  
     403  static GMenuExporter *
     404  g_menu_exporter_group_get_exporter (GMenuExporterGroup *group)
     405  {
     406    return group->exporter;
     407  }
     408  
     409  static gboolean
     410  g_menu_exporter_group_is_subscribed (GMenuExporterGroup *group)
     411  {
     412    return group->subscribed > 0;
     413  }
     414  
     415  static guint
     416  g_menu_exporter_group_get_id (GMenuExporterGroup *group)
     417  {
     418    return group->id;
     419  }
     420  
     421  static void
     422  g_menu_exporter_group_remove_menu (GMenuExporterGroup *group,
     423                                     guint               id)
     424  {
     425    g_hash_table_remove (group->menus, GINT_TO_POINTER (id));
     426  
     427    g_menu_exporter_group_check_if_useless (group);
     428  }
     429  
     430  static GMenuExporterMenu *
     431  g_menu_exporter_group_add_menu (GMenuExporterGroup *group,
     432                                  GMenuModel         *model)
     433  {
     434    GMenuExporterMenu *menu;
     435    guint id;
     436  
     437    id = group->next_menu_id++;
     438    menu = g_menu_exporter_menu_new (group, id, model);
     439    g_hash_table_insert (group->menus, GINT_TO_POINTER (id), menu);
     440  
     441    if (group->prepared)
     442      g_menu_exporter_menu_prepare (menu);
     443  
     444    return menu;
     445  }
     446  
     447  static GMenuExporterGroup *
     448  g_menu_exporter_group_new (GMenuExporter *exporter,
     449                             guint          id)
     450  {
     451    GMenuExporterGroup *group;
     452  
     453    group = g_slice_new0 (GMenuExporterGroup);
     454    group->menus = g_hash_table_new (NULL, NULL);
     455    group->exporter = exporter;
     456    group->id = id;
     457  
     458    return group;
     459  }
     460  
     461  /* {{{1 GMenuExporterRemote */
     462  
     463  struct _GMenuExporterRemote
     464  {
     465    GMenuExporter *exporter;
     466    GHashTable    *watches;
     467    guint          watch_id;
     468  };
     469  
     470  static void
     471  g_menu_exporter_remote_subscribe (GMenuExporterRemote *remote,
     472                                    guint                group_id,
     473                                    GVariantBuilder     *builder)
     474  {
     475    GMenuExporterGroup *group;
     476    guint count;
     477  
     478    count = (gsize) g_hash_table_lookup (remote->watches, GINT_TO_POINTER (group_id));
     479    g_hash_table_insert (remote->watches, GINT_TO_POINTER (group_id), GINT_TO_POINTER (count + 1));
     480  
     481    /* Group will be created (as empty/unsubscribed if it does not exist) */
     482    group = g_menu_exporter_lookup_group (remote->exporter, group_id);
     483    g_menu_exporter_group_subscribe (group, builder);
     484  }
     485  
     486  static void
     487  g_menu_exporter_remote_unsubscribe (GMenuExporterRemote *remote,
     488                                      guint                group_id)
     489  {
     490    GMenuExporterGroup *group;
     491    guint count;
     492  
     493    count = (gsize) g_hash_table_lookup (remote->watches, GINT_TO_POINTER (group_id));
     494  
     495    if (count == 0)
     496      return;
     497  
     498    if (count != 1)
     499      g_hash_table_insert (remote->watches, GINT_TO_POINTER (group_id), GINT_TO_POINTER (count - 1));
     500    else
     501      g_hash_table_remove (remote->watches, GINT_TO_POINTER (group_id));
     502  
     503    group = g_menu_exporter_lookup_group (remote->exporter, group_id);
     504    g_menu_exporter_group_unsubscribe (group, 1);
     505  }
     506  
     507  static gboolean
     508  g_menu_exporter_remote_has_subscriptions (GMenuExporterRemote *remote)
     509  {
     510    return g_hash_table_size (remote->watches) != 0;
     511  }
     512  
     513  static void
     514  g_menu_exporter_remote_free (gpointer data)
     515  {
     516    GMenuExporterRemote *remote = data;
     517    GHashTableIter iter;
     518    gpointer key, val;
     519  
     520    g_hash_table_iter_init (&iter, remote->watches);
     521    while (g_hash_table_iter_next (&iter, &key, &val))
     522      {
     523        GMenuExporterGroup *group;
     524  
     525        group = g_menu_exporter_lookup_group (remote->exporter, GPOINTER_TO_INT (key));
     526        g_menu_exporter_group_unsubscribe (group, GPOINTER_TO_INT (val));
     527      }
     528  
     529    if (remote->watch_id > 0)
     530      g_bus_unwatch_name (remote->watch_id);
     531  
     532    g_hash_table_unref (remote->watches);
     533  
     534    g_slice_free (GMenuExporterRemote, remote);
     535  }
     536  
     537  static GMenuExporterRemote *
     538  g_menu_exporter_remote_new (GMenuExporter *exporter,
     539                              guint          watch_id)
     540  {
     541    GMenuExporterRemote *remote;
     542  
     543    remote = g_slice_new0 (GMenuExporterRemote);
     544    remote->exporter = exporter;
     545    remote->watches = g_hash_table_new (NULL, NULL);
     546    remote->watch_id = watch_id;
     547  
     548    return remote;
     549  }
     550  
     551  /* {{{1 GMenuExporter */
     552  
     553  struct _GMenuExporter
     554  {
     555    GDBusConnection *connection;
     556    gchar *object_path;
     557    guint registration_id;
     558    GHashTable *groups;
     559    guint next_group_id;
     560  
     561    GMenuExporterMenu *root;
     562    GMenuExporterRemote *peer_remote;
     563    GHashTable *remotes;
     564  };
     565  
     566  static void
     567  g_menu_exporter_name_vanished (GDBusConnection *connection,
     568                                 const gchar     *name,
     569                                 gpointer         user_data)
     570  {
     571    GMenuExporter *exporter = user_data;
     572  
     573    /* connection == NULL when we get called because the connection closed */
     574    g_assert (exporter->connection == connection || connection == NULL);
     575  
     576    g_hash_table_remove (exporter->remotes, name);
     577  }
     578  
     579  static GVariant *
     580  g_menu_exporter_subscribe (GMenuExporter *exporter,
     581                             const gchar   *sender,
     582                             GVariant      *group_ids)
     583  {
     584    GMenuExporterRemote *remote;
     585    GVariantBuilder builder;
     586    GVariantIter iter;
     587    guint32 id;
     588  
     589    if (sender != NULL)
     590      remote = g_hash_table_lookup (exporter->remotes, sender);
     591    else
     592      remote = exporter->peer_remote;
     593  
     594    if (remote == NULL)
     595      {
     596        if (sender != NULL)
     597          {
     598            guint watch_id;
     599  
     600            watch_id = g_bus_watch_name_on_connection (exporter->connection, sender, G_BUS_NAME_WATCHER_FLAGS_NONE,
     601                                                       NULL, g_menu_exporter_name_vanished, exporter, NULL);
     602            remote = g_menu_exporter_remote_new (exporter, watch_id);
     603            g_hash_table_insert (exporter->remotes, g_strdup (sender), remote);
     604          }
     605        else
     606          remote = exporter->peer_remote =
     607            g_menu_exporter_remote_new (exporter, 0);
     608      }
     609  
     610    g_variant_builder_init (&builder, G_VARIANT_TYPE ("(a(uuaa{sv}))"));
     611  
     612    g_variant_builder_open (&builder, G_VARIANT_TYPE ("a(uuaa{sv})"));
     613  
     614    g_variant_iter_init (&iter, group_ids);
     615    while (g_variant_iter_next (&iter, "u", &id))
     616      g_menu_exporter_remote_subscribe (remote, id, &builder);
     617  
     618    g_variant_builder_close (&builder);
     619  
     620    return g_variant_builder_end (&builder);
     621  }
     622  
     623  static void
     624  g_menu_exporter_unsubscribe (GMenuExporter *exporter,
     625                               const gchar   *sender,
     626                               GVariant      *group_ids)
     627  {
     628    GMenuExporterRemote *remote;
     629    GVariantIter iter;
     630    guint32 id;
     631  
     632    if (sender != NULL)
     633      remote = g_hash_table_lookup (exporter->remotes, sender);
     634    else
     635      remote = exporter->peer_remote;
     636  
     637    if (remote == NULL)
     638      return;
     639  
     640    g_variant_iter_init (&iter, group_ids);
     641    while (g_variant_iter_next (&iter, "u", &id))
     642      g_menu_exporter_remote_unsubscribe (remote, id);
     643  
     644    if (!g_menu_exporter_remote_has_subscriptions (remote))
     645      {
     646        if (sender != NULL)
     647          g_hash_table_remove (exporter->remotes, sender);
     648        else
     649          g_clear_pointer (&exporter->peer_remote, g_menu_exporter_remote_free);
     650      }
     651  }
     652  
     653  static void
     654  g_menu_exporter_report (GMenuExporter *exporter,
     655                          GVariant      *report)
     656  {
     657    GVariantBuilder builder;
     658  
     659    g_variant_builder_init (&builder, G_VARIANT_TYPE_TUPLE);
     660    g_variant_builder_open (&builder, G_VARIANT_TYPE_ARRAY);
     661    g_variant_builder_add_value (&builder, report);
     662    g_variant_builder_close (&builder);
     663  
     664    g_dbus_connection_emit_signal (exporter->connection,
     665                                   NULL,
     666                                   exporter->object_path,
     667                                   "org.gtk.Menus", "Changed",
     668                                   g_variant_builder_end (&builder),
     669                                   NULL);
     670  }
     671  
     672  static void
     673  g_menu_exporter_remove_group (GMenuExporter *exporter,
     674                                guint          id)
     675  {
     676    g_hash_table_remove (exporter->groups, GINT_TO_POINTER (id));
     677  }
     678  
     679  static GMenuExporterGroup *
     680  g_menu_exporter_lookup_group (GMenuExporter *exporter,
     681                                guint          group_id)
     682  {
     683    GMenuExporterGroup *group;
     684  
     685    group = g_hash_table_lookup (exporter->groups, GINT_TO_POINTER (group_id));
     686  
     687    if (group == NULL)
     688      {
     689        group = g_menu_exporter_group_new (exporter, group_id);
     690        g_hash_table_insert (exporter->groups, GINT_TO_POINTER (group_id), group);
     691      }
     692  
     693    return group;
     694  }
     695  
     696  static GMenuExporterGroup *
     697  g_menu_exporter_create_group (GMenuExporter *exporter)
     698  {
     699    GMenuExporterGroup *group;
     700    guint id;
     701  
     702    id = exporter->next_group_id++;
     703    group = g_menu_exporter_group_new (exporter, id);
     704    g_hash_table_insert (exporter->groups, GINT_TO_POINTER (id), group);
     705  
     706    return group;
     707  }
     708  
     709  static void
     710  g_menu_exporter_free (gpointer user_data)
     711  {
     712    GMenuExporter *exporter = user_data;
     713  
     714    g_menu_exporter_menu_free (exporter->root);
     715    g_clear_pointer (&exporter->peer_remote, g_menu_exporter_remote_free);
     716    g_hash_table_unref (exporter->remotes);
     717    g_hash_table_unref (exporter->groups);
     718    g_object_unref (exporter->connection);
     719    g_free (exporter->object_path);
     720  
     721    g_slice_free (GMenuExporter, exporter);
     722  }
     723  
     724  static void
     725  g_menu_exporter_method_call (GDBusConnection       *connection,
     726                               const gchar           *sender,
     727                               const gchar           *object_path,
     728                               const gchar           *interface_name,
     729                               const gchar           *method_name,
     730                               GVariant              *parameters,
     731                               GDBusMethodInvocation *invocation,
     732                               gpointer               user_data)
     733  {
     734    GMenuExporter *exporter = user_data;
     735    GVariant *group_ids;
     736  
     737    group_ids = g_variant_get_child_value (parameters, 0);
     738  
     739    if (g_str_equal (method_name, "Start"))
     740      g_dbus_method_invocation_return_value (invocation, g_menu_exporter_subscribe (exporter, sender, group_ids));
     741  
     742    else if (g_str_equal (method_name, "End"))
     743      {
     744        g_menu_exporter_unsubscribe (exporter, sender, group_ids);
     745        g_dbus_method_invocation_return_value (invocation, NULL);
     746      }
     747  
     748    else
     749      g_assert_not_reached ();
     750  
     751    g_variant_unref (group_ids);
     752  }
     753  
     754  /* {{{1 Public API */
     755  
     756  /**
     757   * g_dbus_connection_export_menu_model:
     758   * @connection: a #GDBusConnection
     759   * @object_path: a D-Bus object path
     760   * @menu: a #GMenuModel
     761   * @error: return location for an error, or %NULL
     762   *
     763   * Exports @menu on @connection at @object_path.
     764   *
     765   * The implemented D-Bus API should be considered private.
     766   * It is subject to change in the future.
     767   *
     768   * An object path can only have one menu model exported on it. If this
     769   * constraint is violated, the export will fail and 0 will be
     770   * returned (with @error set accordingly).
     771   *
     772   * Exporting menus with sections containing more than
     773   * %G_MENU_EXPORTER_MAX_SECTION_SIZE items is not supported and results in
     774   * undefined behavior.
     775   *
     776   * You can unexport the menu model using
     777   * g_dbus_connection_unexport_menu_model() with the return value of
     778   * this function.
     779   *
     780   * Returns: the ID of the export (never zero), or 0 in case of failure
     781   *
     782   * Since: 2.32
     783   */
     784  guint
     785  g_dbus_connection_export_menu_model (GDBusConnection  *connection,
     786                                       const gchar      *object_path,
     787                                       GMenuModel       *menu,
     788                                       GError          **error)
     789  {
     790    const GDBusInterfaceVTable vtable = {
     791      g_menu_exporter_method_call, NULL, NULL, { 0 }
     792    };
     793    GMenuExporter *exporter;
     794    guint id;
     795  
     796    exporter = g_slice_new0 (GMenuExporter);
     797  
     798    id = g_dbus_connection_register_object (connection, object_path, org_gtk_Menus_get_interface (),
     799                                            &vtable, exporter, g_menu_exporter_free, error);
     800  
     801    if (id == 0)
     802      {
     803        g_slice_free (GMenuExporter, exporter);
     804        return 0;
     805      }
     806  
     807    exporter->connection = g_object_ref (connection);
     808    exporter->object_path = g_strdup (object_path);
     809    exporter->groups = g_hash_table_new (NULL, NULL);
     810    exporter->remotes = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, g_menu_exporter_remote_free);
     811    exporter->root = g_menu_exporter_group_add_menu (g_menu_exporter_create_group (exporter), menu);
     812  
     813    return id;
     814  }
     815  
     816  /**
     817   * g_dbus_connection_unexport_menu_model:
     818   * @connection: a #GDBusConnection
     819   * @export_id: the ID from g_dbus_connection_export_menu_model()
     820   *
     821   * Reverses the effect of a previous call to
     822   * g_dbus_connection_export_menu_model().
     823   *
     824   * It is an error to call this function with an ID that wasn't returned
     825   * from g_dbus_connection_export_menu_model() or to call it with the
     826   * same ID more than once.
     827   *
     828   * Since: 2.32
     829   */
     830  void
     831  g_dbus_connection_unexport_menu_model (GDBusConnection *connection,
     832                                         guint            export_id)
     833  {
     834    g_dbus_connection_unregister_object (connection, export_id);
     835  }
     836  
     837  /* {{{1 Epilogue */
     838  /* vim:set foldmethod=marker: */