gio/gactiongroupexporter.c

   1 /*
   2  * Copyright © 2010 Codethink Limited
   3  * Copyright © 2011 Canonical Limited
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU Lesser General Public License as published
   7  * by the Free Software Foundation; either version 2 of the licence or (at
   8  * 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
  16  * Public 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  * Authors: Ryan Lortie <desrt@desrt.ca>
  21  */
  22
  23 #include "config.h"
  24
  25 #include "gactiongroupexporter.h"
  26
  27 #include "gdbusmethodinvocation.h"
  28 #include "gdbusintrospection.h"
  29 #include "gdbusconnection.h"
  30 #include "gactiongroup.h"
  31 #include "gapplication.h"
  32 #include "gdbuserror.h"
  33
  34 /**
  35  * SECTION:gactiongroupexporter
  36  * @title: GActionGroup exporter
  37  * @short_description: Export GActionGroups on D-Bus
  38  * @see_also: #GActionGroup, #GDBusActionGroup
  39  *
  40  * These functions support exporting a #GActionGroup on D-Bus.
  41  * The D-Bus interface that is used is a private implementation
  42  * detail.
  43  *
  44  * To access an exported #GActionGroup remotely, use
  45  * g_dbus_action_group_new() to obtain a #GDBusActionGroup.
  46  */
  47
  48 G_GNUC_INTERNAL GVariant *
  49 g_action_group_describe_action (GActionGroup *action_group,
  50                                 const gchar  *name)
  51 {
  52   const GVariantType *type;
  53   GVariantBuilder builder;
  54   gboolean enabled;
  55   GVariant *state;
  56
  57   g_variant_builder_init (&builder, G_VARIANT_TYPE ("(bgav)"));
  58
  59   enabled = g_action_group_get_action_enabled (action_group, name);
  60   g_variant_builder_add (&builder, "b", enabled);
  61
  62   if ((type = g_action_group_get_action_parameter_type (action_group, name)))
  63     {
  64       gchar *str = g_variant_type_dup_string (type);
  65       g_variant_builder_add (&builder, "g", str);
  66       g_free (str);
  67     }
  68   else
  69     g_variant_builder_add (&builder, "g", "");
  70
  71   g_variant_builder_open (&builder, G_VARIANT_TYPE ("av"));
  72   if ((state = g_action_group_get_action_state (action_group, name)))
  73     {
  74       g_variant_builder_add (&builder, "v", state);
  75       g_variant_unref (state);
  76     }
  77   g_variant_builder_close (&builder);
  78
  79   return g_variant_builder_end (&builder);
  80 }
  81
  82 /* The org.gtk.Actions interface
  83  * =============================
  84  *
  85  * This interface describes a group of actions.
  86  *
  87  * Each action:
  88  * - has a unique string name
  89  * - can be activated
  90  * - optionally has a parameter type that must be given to the activation
  91  * - has an enabled state that may be true or false
  92  * - optionally has a state which can change value, but not type
  93  *
  94  * Methods
  95  * -------
  96  *
  97  * List :: () → (as)
  98  *
  99  *   Lists the names of the actions exported at this object path.
 100  *
 101  * Describe :: (s) → (bgav)
 102  *
 103  *   Describes a single action, or a given name.
 104  *
 105  *   The return value has the following components:
 106  *   b: specifies if the action is currently enabled. This is
 107  *      a hint that attempting to interact with the action will
 108  *      produce no effect.
 109  *   g: specifies the optional parameter type. If not "",
 110  *      the string specifies the type of argument that must
 111  *      be passed to the activation.
 112  *   av: specifies the optional state. If not empty, the array
 113  *       contains the current value of the state as a variant
 114  *
 115  * DescribeAll :: () → (a{s(bgav)})
 116  *
 117  *   Describes all actions in a single round-trip.
 118  *
 119  *   The dictionary maps action name strings to their descriptions
 120  *   (in the format discussed above).
 121  *
 122  * Activate :: (sava{sv}) → ()
 123  *
 124  *   Requests activation of the named action.
 125  *
 126  *   The action is named by the first parameter (s).
 127  *
 128  *   If the action activation requires a parameter then this parameter
 129  *   must be given in the second parameter (av). If there is no parameter
 130  *   to be specified, the array must be empty.
 131  *
 132  *   The final parameter (a{sv}) is a list of "platform data".
 133  *
 134  *   This method is not guaranteed to have any particular effect. The
 135  *   implementation may take some action (including changing the state
 136  *   of the action, if it is stateful) or it may take none at all. In
 137  *   particular, callers should expect their request to be completely
 138  *   ignored when the enabled flag is false (but even this is not
 139  *   guaranteed).
 140  *
 141  * SetState :: (sva{sv}) → ()
 142  *
 143  *   Requests the state of an action to be changed to the given value.
 144  *
 145  *   The action is named by the first parameter (s).
 146  *
 147  *   The requested new state is given in the second parameter (v).
 148  *   It must be equal in type to the existing state.
 149  *
 150  *   The final parameter (a{sv}) is a list of "platform data".
 151  *
 152  *   This method is not guaranteed to have any particular effect.
 153  *   The implementation of an action can choose to ignore the requested
 154  *   state change, or choose to change its state to something else or
 155  *   to trigger other side effects. In particular, callers should expect
 156  *   their request to be completely ignored when the enabled flag is
 157  *   false (but even this is not guaranteed).
 158  *
 159  * Signals
 160  * -------
 161  *
 162  * Changed :: (asa{sb}a{sv}a{s(bgav)})
 163  *
 164  *   Signals that some change has occured to the action group.
 165  *
 166  *   Four separate types of changes are possible, and the 4 parameters
 167  *   of the change signal reflect these possibilities:
 168  *   as: a list of removed actions
 169  *   a{sb}: a list of actions that had their enabled flag changed
 170  *   a{sv}: a list of actions that had their state changed
 171  *   a{s(bgav)}: a list of new actions added in the same format as
 172  *               the return value of the DescribeAll method
 173  */
 174
 175 /* Using XML saves us dozens of relocations vs. using the introspection
 176  * structure types.  We only need to burn cycles and memory if we
 177  * actually use the exporter -- not in every single app using GIO.
 178  *
 179  * It's also a lot easier to read. :)
 180  */
 181 const char org_gtk_Actions_xml[] =
 182   "<node>"
 183   "  <interface name='org.gtk.Actions'>"
 184   "    <method name='List'>"
 185   "      <arg type='as' name='list' direction='out'/>"
 186   "    </method>"
 187   "    <method name='Describe'>"
 188   "      <arg type='s' name='action_name' direction='in'/>"
 189   "      <arg type='(bgav)' name='description' direction='out'/>"
 190   "    </method>"
 191   "    <method name='DescribeAll'>"
 192   "      <arg type='a{s(bgav)}' name='descriptions' direction='out'/>"
 193   "    </method>"
 194   "    <method name='Activate'>"
 195   "      <arg type='s' name='action_name' direction='in'/>"
 196   "      <arg type='av' name='parameter' direction='in'/>"
 197   "      <arg type='a{sv}' name='platform_data' direction='in'/>"
 198   "    </method>"
 199   "    <method name='SetState'>"
 200   "      <arg type='s' name='action_name' direction='in'/>"
 201   "      <arg type='v' name='value' direction='in'/>"
 202   "      <arg type='a{sv}' name='platform_data' direction='in'/>"
 203   "    </method>"
 204   "    <signal name='Changed'>"
 205   "      <arg type='as' name='removals'/>"
 206   "      <arg type='a{sb}' name='enable_changes'/>"
 207   "      <arg type='a{sv}' name='state_changes'/>"
 208   "      <arg type='a{s(bgav)}' name='additions'/>"
 209   "    </signal>"
 210   "  </interface>"
 211   "</node>";
 212
 213 static GDBusInterfaceInfo *org_gtk_Actions;
 214
 215 typedef struct
 216 {
 217   GActionGroup    *action_group;
 218   GDBusConnection *connection;
 219   GMainContext    *context;
 220   gchar           *object_path;
 221   GHashTable      *pending_changes;
 222   GSource         *pending_source;
 223 } GActionGroupExporter;
 224
 225 #define ACTION_ADDED_EVENT             (1u<<0)
 226 #define ACTION_REMOVED_EVENT           (1u<<1)
 227 #define ACTION_STATE_CHANGED_EVENT     (1u<<2)
 228 #define ACTION_ENABLED_CHANGED_EVENT   (1u<<3)
 229
 230 static gboolean
 231 g_action_group_exporter_dispatch_events (gpointer user_data)
 232 {
 233   GActionGroupExporter *exporter = user_data;
 234   GVariantBuilder removes;
 235   GVariantBuilder enabled_changes;
 236   GVariantBuilder state_changes;
 237   GVariantBuilder adds;
 238   GHashTableIter iter;
 239   gpointer value;
 240   gpointer key;
 241
 242   g_variant_builder_init (&removes, G_VARIANT_TYPE_STRING_ARRAY);
 243   g_variant_builder_init (&enabled_changes, G_VARIANT_TYPE ("a{sb}"));
 244   g_variant_builder_init (&state_changes, G_VARIANT_TYPE ("a{sv}"));
 245   g_variant_builder_init (&adds, G_VARIANT_TYPE ("a{s(bgav)}"));
 246
 247   g_hash_table_iter_init (&iter, exporter->pending_changes);
 248   while (g_hash_table_iter_next (&iter, &key, &value))
 249     {
 250       guint events = GPOINTER_TO_INT (value);
 251       const gchar *name = key;
 252
 253       /* Adds and removes are incompatible with enabled or state
 254        * changes, but we must report at least one event.
 255        */
 256       g_assert (((events & (ACTION_ENABLED_CHANGED_EVENT | ACTION_STATE_CHANGED_EVENT)) == 0) !=
 257                 ((events & (ACTION_REMOVED_EVENT | ACTION_ADDED_EVENT)) == 0));
 258
 259       if (events & ACTION_REMOVED_EVENT)
 260         g_variant_builder_add (&removes, "s", name);
 261
 262       if (events & ACTION_ENABLED_CHANGED_EVENT)
 263         {
 264           gboolean enabled;
 265
 266           enabled = g_action_group_get_action_enabled (exporter->action_group, name);
 267           g_variant_builder_add (&enabled_changes, "{sb}", name, enabled);
 268         }
 269
 270       if (events & ACTION_STATE_CHANGED_EVENT)
 271         {
 272           GVariant *state;
 273
 274           state = g_action_group_get_action_state (exporter->action_group, name);
 275           g_variant_builder_add (&state_changes, "{sv}", name, state);
 276           g_variant_unref (state);
 277         }
 278
 279       if (events & ACTION_ADDED_EVENT)
 280         {
 281           GVariant *description;
 282
 283           description = g_action_group_describe_action (exporter->action_group, name);
 284           g_variant_builder_add (&adds, "{s@(bgav)}", name, description);
 285         }
 286     }
 287
 288   g_hash_table_remove_all (exporter->pending_changes);
 289
 290   g_dbus_connection_emit_signal (exporter->connection, NULL, exporter->object_path,
 291                                  "org.gtk.Actions", "Changed",
 292                                  g_variant_new ("(asa{sb}a{sv}a{s(bgav)})",
 293                                                 &removes, &enabled_changes,
 294                                                 &state_changes, &adds),
 295                                  NULL);
 296
 297   exporter->pending_source = NULL;
 298
 299   return FALSE;
 300 }
 301
 302 static guint
 303 g_action_group_exporter_get_events (GActionGroupExporter *exporter,
 304                                     const gchar          *name)
 305 {
 306   return (gsize) g_hash_table_lookup (exporter->pending_changes, name);
 307 }
 308
 309 static void
 310 g_action_group_exporter_set_events (GActionGroupExporter *exporter,
 311                                     const gchar          *name,
 312                                     guint                 events)
 313 {
 314   gboolean have_events;
 315   gboolean is_queued;
 316
 317   if (events != 0)
 318     g_hash_table_insert (exporter->pending_changes, g_strdup (name), GINT_TO_POINTER (events));
 319   else
 320     g_hash_table_remove (exporter->pending_changes, name);
 321
 322   have_events = g_hash_table_size (exporter->pending_changes) > 0;
 323   is_queued = exporter->pending_source != NULL;
 324
 325   if (have_events && !is_queued)
 326     {
 327       GSource *source;
 328
 329       source = g_idle_source_new ();
 330       exporter->pending_source = source;
 331       g_source_set_callback (source, g_action_group_exporter_dispatch_events, exporter, NULL);
 332       g_source_attach (source, exporter->context);
 333       g_source_unref (source);
 334     }
 335
 336   if (!have_events && is_queued)
 337     {
 338       g_source_destroy (exporter->pending_source);
 339       exporter->pending_source = NULL;
 340     }
 341 }
 342
 343 static void
 344 g_action_group_exporter_action_added (GActionGroup *action_group,
 345                                       const gchar  *action_name,
 346                                       gpointer      user_data)
 347 {
 348   GActionGroupExporter *exporter = user_data;
 349   guint event_mask;
 350
 351   event_mask = g_action_group_exporter_get_events (exporter, action_name);
 352
 353   /* The action is new, so we should not have any pending
 354    * enabled-changed or state-changed signals for it.
 355    */
 356   g_assert (~event_mask & (ACTION_STATE_CHANGED_EVENT |
 357                            ACTION_ENABLED_CHANGED_EVENT));
 358
 359   event_mask |= ACTION_ADDED_EVENT;
 360
 361   g_action_group_exporter_set_events (exporter, action_name, event_mask);
 362 }
 363
 364 static void
 365 g_action_group_exporter_action_removed (GActionGroup *action_group,
 366                                         const gchar  *action_name,
 367                                         gpointer      user_data)
 368 {
 369   GActionGroupExporter *exporter = user_data;
 370   guint event_mask;
 371
 372   event_mask = g_action_group_exporter_get_events (exporter, action_name);
 373
 374   /* If the add event for this is still queued then just cancel it since
 375    * it's gone now.
 376    *
 377    * If the event was freshly added, there should not have been any
 378    * enabled or state changed events.
 379    */
 380   if (event_mask & ACTION_ADDED_EVENT)
 381     {
 382       g_assert (~event_mask & ~(ACTION_STATE_CHANGED_EVENT | ACTION_ENABLED_CHANGED_EVENT));
 383       event_mask &= ~ACTION_ADDED_EVENT;
 384     }
 385
 386   /* Otherwise, queue a remove event.  Drop any state or enabled changes
 387    * that were queued before the remove. */
 388   else
 389     {
 390       event_mask |= ACTION_REMOVED_EVENT;
 391       event_mask &= ~(ACTION_STATE_CHANGED_EVENT | ACTION_ENABLED_CHANGED_EVENT);
 392     }
 393
 394   g_action_group_exporter_set_events (exporter, action_name, event_mask);
 395 }
 396
 397 static void
 398 g_action_group_exporter_action_state_changed (GActionGroup *action_group,
 399                                               const gchar  *action_name,
 400                                               GVariant     *value,
 401                                               gpointer      user_data)
 402 {
 403   GActionGroupExporter *exporter = user_data;
 404   guint event_mask;
 405
 406   event_mask = g_action_group_exporter_get_events (exporter, action_name);
 407
 408   /* If it was removed, it must have been added back.  Otherwise, why
 409    * are we hearing about changes?
 410    */
 411   g_assert (~event_mask & ACTION_REMOVED_EVENT ||
 412             event_mask & ACTION_ADDED_EVENT);
 413
 414   /* If it is freshly added, don't also bother with the state change
 415    * signal since the updated state will be sent as part of the pending
 416    * add message.
 417    */
 418   if (~event_mask & ACTION_ADDED_EVENT)
 419     event_mask |= ACTION_STATE_CHANGED_EVENT;
 420
 421   g_action_group_exporter_set_events (exporter, action_name, event_mask);
 422 }
 423
 424 static void
 425 g_action_group_exporter_action_enabled_changed (GActionGroup *action_group,
 426                                                 const gchar  *action_name,
 427                                                 gboolean      enabled,
 428                                                 gpointer      user_data)
 429 {
 430   GActionGroupExporter *exporter = user_data;
 431   guint event_mask;
 432
 433   event_mask = g_action_group_exporter_get_events (exporter, action_name);
 434
 435   /* Reasoning as above. */
 436   g_assert (~event_mask & ACTION_REMOVED_EVENT ||
 437             event_mask & ACTION_ADDED_EVENT);
 438
 439   if (~event_mask & ACTION_ADDED_EVENT)
 440     event_mask |= ACTION_ENABLED_CHANGED_EVENT;
 441
 442   g_action_group_exporter_set_events (exporter, action_name, event_mask);
 443 }
 444
 445 static void
 446 g_action_group_exporter_pre_emit (GActionGroupExporter *exporter,
 447                                   GVariant             *platform_data)
 448 {
 449   if (G_IS_APPLICATION (exporter->action_group))
 450     G_APPLICATION_GET_CLASS (exporter->action_group)
 451       ->before_emit (G_APPLICATION (exporter->action_group), platform_data);
 452 }
 453
 454 static void
 455 g_action_group_exporter_post_emit (GActionGroupExporter *exporter,
 456                                    GVariant             *platform_data)
 457 {
 458   if (G_IS_APPLICATION (exporter->action_group))
 459     G_APPLICATION_GET_CLASS (exporter->action_group)
 460       ->after_emit (G_APPLICATION (exporter->action_group), platform_data);
 461 }
 462
 463 static void
 464 org_gtk_Actions_method_call (GDBusConnection       *connection,
 465                              const gchar           *sender,
 466                              const gchar           *object_path,
 467                              const gchar           *interface_name,
 468                              const gchar           *method_name,
 469                              GVariant              *parameters,
 470                              GDBusMethodInvocation *invocation,
 471                              gpointer               user_data)
 472 {
 473   GActionGroupExporter *exporter = user_data;
 474   GVariant *result = NULL;
 475
 476   if (g_str_equal (method_name, "List"))
 477     {
 478       gchar **list;
 479
 480       list = g_action_group_list_actions (exporter->action_group);
 481       result = g_variant_new ("(^as)", list);
 482       g_strfreev (list);
 483     }
 484
 485   else if (g_str_equal (method_name, "Describe"))
 486     {
 487       const gchar *name;
 488       GVariant *desc;
 489
 490       g_variant_get (parameters, "(&s)", &name);
 491       desc = g_action_group_describe_action (exporter->action_group, name);
 492       result = g_variant_new ("(@(bgav))", desc);
 493     }
 494
 495   else if (g_str_equal (method_name, "DescribeAll"))
 496     {
 497       GVariantBuilder builder;
 498       gchar **list;
 499       gint i;
 500
 501       list = g_action_group_list_actions (exporter->action_group);
 502       g_variant_builder_init (&builder, G_VARIANT_TYPE ("a{s(bgav)}"));
 503       for (i = 0; list[i]; i++)
 504         {
 505           const gchar *name = list[i];
 506           GVariant *description;
 507
 508           description = g_action_group_describe_action (exporter->action_group, name);
 509           g_variant_builder_add (&builder, "{s@(bgav)}", name, description);
 510         }
 511       result = g_variant_new ("(a{s(bgav)})", &builder);
 512       g_strfreev (list);
 513     }
 514
 515   else if (g_str_equal (method_name, "Activate"))
 516     {
 517       GVariant *parameter = NULL;
 518       GVariant *platform_data;
 519       GVariantIter *iter;
 520       const gchar *name;
 521
 522       g_variant_get (parameters, "(&sav@a{sv})", &name, &iter, &platform_data);
 523       g_variant_iter_next (iter, "v", &parameter);
 524       g_variant_iter_free (iter);
 525
 526       g_action_group_exporter_pre_emit (exporter, platform_data);
 527       g_action_group_activate_action (exporter->action_group, name, parameter);
 528       g_action_group_exporter_post_emit (exporter, platform_data);
 529
 530       if (parameter)
 531         g_variant_unref (parameter);
 532
 533       g_variant_unref (platform_data);
 534     }
 535
 536   else if (g_str_equal (method_name, "SetState"))
 537     {
 538       GVariant *platform_data;
 539       const gchar *name;
 540       GVariant *state;
 541
 542       g_variant_get (parameters, "(&sv@a{sv})", &name, &state, &platform_data);
 543       g_action_group_exporter_pre_emit (exporter, platform_data);
 544       g_action_group_change_action_state (exporter->action_group, name, state);
 545       g_action_group_exporter_post_emit (exporter, platform_data);
 546       g_variant_unref (platform_data);
 547       g_variant_unref (state);
 548     }
 549
 550   else
 551     g_assert_not_reached ();
 552
 553   g_dbus_method_invocation_return_value (invocation, result);
 554 }
 555
 556 static void
 557 g_action_group_exporter_free (gpointer user_data)
 558 {
 559   GActionGroupExporter *exporter = user_data;
 560
 561   g_signal_handlers_disconnect_by_func (exporter->action_group,
 562                                         g_action_group_exporter_action_added, exporter);
 563   g_signal_handlers_disconnect_by_func (exporter->action_group,
 564                                         g_action_group_exporter_action_enabled_changed, exporter);
 565   g_signal_handlers_disconnect_by_func (exporter->action_group,
 566                                         g_action_group_exporter_action_state_changed, exporter);
 567   g_signal_handlers_disconnect_by_func (exporter->action_group,
 568                                         g_action_group_exporter_action_removed, exporter);
 569
 570   g_hash_table_unref (exporter->pending_changes);
 571   if (exporter->pending_source)
 572     g_source_destroy (exporter->pending_source);
 573
 574   g_main_context_unref (exporter->context);
 575   g_object_unref (exporter->connection);
 576   g_object_unref (exporter->action_group);
 577   g_free (exporter->object_path);
 578
 579   g_slice_free (GActionGroupExporter, exporter);
 580 }
 581
 582 /**
 583  * g_dbus_connection_export_action_group:
 584  * @connection: a #GDBusConnection
 585  * @object_path: a D-Bus object path
 586  * @action_group: a #GActionGroup
 587  * @error: a pointer to a %NULL #GError, or %NULL
 588  *
 589  * Exports @action_group on @connection at @object_path.
 590  *
 591  * The implemented D-Bus API should be considered private.  It is
 592  * subject to change in the future.
 593  *
 594  * A given object path can only have one action group exported on it.
 595  * If this constraint is violated, the export will fail and 0 will be
 596  * returned (with @error set accordingly).
 597  *
 598  * You can unexport the action group using
 599  * g_dbus_connection_unexport_action_group() with the return value of
 600  * this function.
 601  *
 602  * The thread default main context is taken at the time of this call.
 603  * All incoming action activations and state change requests are
 604  * reported from this context.  Any changes on the action group that
 605  * cause it to emit signals must also come from this same context.
 606  * Since incoming action activations and state change requests are
 607  * rather likely to cause changes on the action group, this effectively
 608  * limits a given action group to being exported from only one main
 609  * context.
 610  *
 611  * Returns: the ID of the export (never zero), or 0 in case of failure
 612  *
 613  * Since: 2.32
 614  **/
 615 guint
 616 g_dbus_connection_export_action_group (GDBusConnection  *connection,
 617                                        const gchar      *object_path,
 618                                        GActionGroup     *action_group,
 619                                        GError          **error)
 620 {
 621   const GDBusInterfaceVTable vtable = {
 622     org_gtk_Actions_method_call
 623   };
 624   GActionGroupExporter *exporter;
 625   guint id;
 626
 627   if G_UNLIKELY (org_gtk_Actions == NULL)
 628     {
 629       GError *error = NULL;
 630       GDBusNodeInfo *info;
 631
 632       info = g_dbus_node_info_new_for_xml (org_gtk_Actions_xml, &error);
 633       if G_UNLIKELY (info == NULL)
 634         g_error ("%s", error->message);
 635       org_gtk_Actions = g_dbus_node_info_lookup_interface (info, "org.gtk.Actions");
 636       g_assert (org_gtk_Actions != NULL);
 637       g_dbus_interface_info_ref (org_gtk_Actions);
 638       g_dbus_node_info_unref (info);
 639     }
 640
 641   exporter = g_slice_new (GActionGroupExporter);
 642   id = g_dbus_connection_register_object (connection, object_path, org_gtk_Actions, &vtable,
 643                                           exporter, g_action_group_exporter_free, error);
 644
 645   if (id == 0)
 646     {
 647       g_slice_free (GActionGroupExporter, exporter);
 648       return 0;
 649     }
 650
 651   exporter->context = g_main_context_ref_thread_default ();
 652   exporter->pending_changes = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL);
 653   exporter->pending_source = NULL;
 654   exporter->action_group = g_object_ref (action_group);
 655   exporter->connection = g_object_ref (connection);
 656   exporter->object_path = g_strdup (object_path);
 657
 658   g_signal_connect (action_group, "action-added",
 659                     G_CALLBACK (g_action_group_exporter_action_added), exporter);
 660   g_signal_connect (action_group, "action-removed",
 661                     G_CALLBACK (g_action_group_exporter_action_removed), exporter);
 662   g_signal_connect (action_group, "action-state-changed",
 663                     G_CALLBACK (g_action_group_exporter_action_state_changed), exporter);
 664   g_signal_connect (action_group, "action-enabled-changed",
 665                     G_CALLBACK (g_action_group_exporter_action_enabled_changed), exporter);
 666
 667   return id;
 668 }
 669
 670 /**
 671  * g_dbus_connection_unexport_action_group:
 672  * @connection: a #GDBusConnection
 673  * @export_id: the ID from g_dbus_connection_export_action_group()
 674  *
 675  * Reverses the effect of a previous call to
 676  * g_dbus_connection_export_action_group().
 677  *
 678  * It is an error to call this function with an ID that wasn't returned
 679  * from g_dbus_connection_export_action_group() or to call it with the
 680  * same ID more than once.
 681  *
 682  * Since: 2.32
 683  **/
 684 void
 685 g_dbus_connection_unexport_action_group (GDBusConnection *connection,
 686                                          guint            export_id)
 687 {
 688   g_dbus_connection_unregister_object (connection, export_id);
 689 }