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, see <http://www.gnu.org/licenses/>.
  17  *
  18  * Authors: Ryan Lortie <desrt@desrt.ca>
  19  */
  20
  21 #include "config.h"
  22
  23 #include "gactiongroupexporter.h"
  24
  25 #include "gdbusmethodinvocation.h"
  26 #include "gremoteactiongroup.h"
  27 #include "gdbusintrospection.h"
  28 #include "gdbusconnection.h"
  29 #include "gactiongroup.h"
  30 #include "gdbuserror.h"
  31
  32 /**
  33  * SECTION:gactiongroupexporter
  34  * @title: GActionGroup exporter
  35  * @include: gio/gio.h
  36  * @short_description: Export GActionGroups on D-Bus
  37  * @see_also: #GActionGroup, #GDBusActionGroup
  38  *
  39  * These functions support exporting a #GActionGroup on D-Bus.
  40  * The D-Bus interface that is used is a private implementation
  41  * detail.
  42  *
  43  * To access an exported #GActionGroup remotely, use
  44  * g_dbus_action_group_get() to obtain a #GDBusActionGroup.
  45  */
  46
  47 static GVariant *
  48 g_action_group_describe_action (GActionGroup *action_group,
  49                                 const gchar  *name)
  50 {
  51   const GVariantType *type;
  52   GVariantBuilder builder;
  53   gboolean enabled;
  54   GVariant *state;
  55
  56   g_variant_builder_init (&builder, G_VARIANT_TYPE ("(bgav)"));
  57
  58   enabled = g_action_group_get_action_enabled (action_group, name);
  59   g_variant_builder_add (&builder, "b", enabled);
  60
  61   if ((type = g_action_group_get_action_parameter_type (action_group, name)))
  62     {
  63       gchar *str = g_variant_type_dup_string (type);
  64       g_variant_builder_add (&builder, "g", str);
  65       g_free (str);
  66     }
  67   else
  68     g_variant_builder_add (&builder, "g", "");
  69
  70   g_variant_builder_open (&builder, G_VARIANT_TYPE ("av"));
  71   if ((state = g_action_group_get_action_state (action_group, name)))
  72     {
  73       g_variant_builder_add (&builder, "v", state);
  74       g_variant_unref (state);
  75     }
  76   g_variant_builder_close (&builder);
  77
  78   return g_variant_builder_end (&builder);
  79 }
  80
  81 /* Using XML saves us dozens of relocations vs. using the introspection
  82  * structure types.  We only need to burn cycles and memory if we
  83  * actually use the exporter -- not in every single app using GIO.
  84  *
  85  * It's also a lot easier to read. :)
  86  *
  87  * For documentation of this interface, see
  88  * https://wiki.gnome.org/Projects/GLib/GApplication/DBusAPI
  89  */
  90 const char org_gtk_Actions_xml[] =
  91   "<node>"
  92   "  <interface name='org.gtk.Actions'>"
  93   "    <method name='List'>"
  94   "      <arg type='as' name='list' direction='out'/>"
  95   "    </method>"
  96   "    <method name='Describe'>"
  97   "      <arg type='s' name='action_name' direction='in'/>"
  98   "      <arg type='(bgav)' name='description' direction='out'/>"
  99   "    </method>"
 100   "    <method name='DescribeAll'>"
 101   "      <arg type='a{s(bgav)}' name='descriptions' direction='out'/>"
 102   "    </method>"
 103   "    <method name='Activate'>"
 104   "      <arg type='s' name='action_name' direction='in'/>"
 105   "      <arg type='av' name='parameter' direction='in'/>"
 106   "      <arg type='a{sv}' name='platform_data' direction='in'/>"
 107   "    </method>"
 108   "    <method name='SetState'>"
 109   "      <arg type='s' name='action_name' direction='in'/>"
 110   "      <arg type='v' name='value' direction='in'/>"
 111   "      <arg type='a{sv}' name='platform_data' direction='in'/>"
 112   "    </method>"
 113   "    <signal name='Changed'>"
 114   "      <arg type='as' name='removals'/>"
 115   "      <arg type='a{sb}' name='enable_changes'/>"
 116   "      <arg type='a{sv}' name='state_changes'/>"
 117   "      <arg type='a{s(bgav)}' name='additions'/>"
 118   "    </signal>"
 119   "  </interface>"
 120   "</node>";
 121
 122 static GDBusInterfaceInfo *org_gtk_Actions;
 123
 124 typedef struct
 125 {
 126   GActionGroup    *action_group;
 127   GDBusConnection *connection;
 128   GMainContext    *context;
 129   gchar           *object_path;
 130   GHashTable      *pending_changes;
 131   GSource         *pending_source;
 132 } GActionGroupExporter;
 133
 134 #define ACTION_ADDED_EVENT             (1u<<0)
 135 #define ACTION_REMOVED_EVENT           (1u<<1)
 136 #define ACTION_STATE_CHANGED_EVENT     (1u<<2)
 137 #define ACTION_ENABLED_CHANGED_EVENT   (1u<<3)
 138
 139 static gboolean
 140 g_action_group_exporter_dispatch_events (gpointer user_data)
 141 {
 142   GActionGroupExporter *exporter = user_data;
 143   GVariantBuilder removes;
 144   GVariantBuilder enabled_changes;
 145   GVariantBuilder state_changes;
 146   GVariantBuilder adds;
 147   GHashTableIter iter;
 148   gpointer value;
 149   gpointer key;
 150
 151   g_variant_builder_init (&removes, G_VARIANT_TYPE_STRING_ARRAY);
 152   g_variant_builder_init (&enabled_changes, G_VARIANT_TYPE ("a{sb}"));
 153   g_variant_builder_init (&state_changes, G_VARIANT_TYPE ("a{sv}"));
 154   g_variant_builder_init (&adds, G_VARIANT_TYPE ("a{s(bgav)}"));
 155
 156   g_hash_table_iter_init (&iter, exporter->pending_changes);
 157   while (g_hash_table_iter_next (&iter, &key, &value))
 158     {
 159       guint events = GPOINTER_TO_INT (value);
 160       const gchar *name = key;
 161
 162       /* Adds and removes are incompatible with enabled or state
 163        * changes, but we must report at least one event.
 164        */
 165       g_assert (((events & (ACTION_ENABLED_CHANGED_EVENT | ACTION_STATE_CHANGED_EVENT)) == 0) !=
 166                 ((events & (ACTION_REMOVED_EVENT | ACTION_ADDED_EVENT)) == 0));
 167
 168       if (events & ACTION_REMOVED_EVENT)
 169         g_variant_builder_add (&removes, "s", name);
 170
 171       if (events & ACTION_ENABLED_CHANGED_EVENT)
 172         {
 173           gboolean enabled;
 174
 175           enabled = g_action_group_get_action_enabled (exporter->action_group, name);
 176           g_variant_builder_add (&enabled_changes, "{sb}", name, enabled);
 177         }
 178
 179       if (events & ACTION_STATE_CHANGED_EVENT)
 180         {
 181           GVariant *state;
 182
 183           state = g_action_group_get_action_state (exporter->action_group, name);
 184           g_variant_builder_add (&state_changes, "{sv}", name, state);
 185           g_variant_unref (state);
 186         }
 187
 188       if (events & ACTION_ADDED_EVENT)
 189         {
 190           GVariant *description;
 191
 192           description = g_action_group_describe_action (exporter->action_group, name);
 193           g_variant_builder_add (&adds, "{s@(bgav)}", name, description);
 194         }
 195     }
 196
 197   g_hash_table_remove_all (exporter->pending_changes);
 198
 199   g_dbus_connection_emit_signal (exporter->connection, NULL, exporter->object_path,
 200                                  "org.gtk.Actions", "Changed",
 201                                  g_variant_new ("(asa{sb}a{sv}a{s(bgav)})",
 202                                                 &removes, &enabled_changes,
 203                                                 &state_changes, &adds),
 204                                  NULL);
 205
 206   exporter->pending_source = NULL;
 207
 208   return FALSE;
 209 }
 210
 211 static guint
 212 g_action_group_exporter_get_events (GActionGroupExporter *exporter,
 213                                     const gchar          *name)
 214 {
 215   return (gsize) g_hash_table_lookup (exporter->pending_changes, name);
 216 }
 217
 218 static void
 219 g_action_group_exporter_set_events (GActionGroupExporter *exporter,
 220                                     const gchar          *name,
 221                                     guint                 events)
 222 {
 223   gboolean have_events;
 224   gboolean is_queued;
 225
 226   if (events != 0)
 227     g_hash_table_insert (exporter->pending_changes, g_strdup (name), GINT_TO_POINTER (events));
 228   else
 229     g_hash_table_remove (exporter->pending_changes, name);
 230
 231   have_events = g_hash_table_size (exporter->pending_changes) > 0;
 232   is_queued = exporter->pending_source != NULL;
 233
 234   if (have_events && !is_queued)
 235     {
 236       GSource *source;
 237
 238       source = g_idle_source_new ();
 239       exporter->pending_source = source;
 240       g_source_set_callback (source, g_action_group_exporter_dispatch_events, exporter, NULL);
 241       g_source_set_name (source, "[gio] g_action_group_exporter_dispatch_events");
 242       g_source_attach (source, exporter->context);
 243       g_source_unref (source);
 244     }
 245
 246   if (!have_events && is_queued)
 247     {
 248       g_source_destroy (exporter->pending_source);
 249       exporter->pending_source = NULL;
 250     }
 251 }
 252
 253 static void
 254 g_action_group_exporter_action_added (GActionGroup *action_group,
 255                                       const gchar  *action_name,
 256                                       gpointer      user_data)
 257 {
 258   GActionGroupExporter *exporter = user_data;
 259   guint event_mask;
 260
 261   event_mask = g_action_group_exporter_get_events (exporter, action_name);
 262
 263   /* The action is new, so we should not have any pending
 264    * enabled-changed or state-changed signals for it.
 265    */
 266   g_assert (~event_mask & (ACTION_STATE_CHANGED_EVENT |
 267                            ACTION_ENABLED_CHANGED_EVENT));
 268
 269   event_mask |= ACTION_ADDED_EVENT;
 270
 271   g_action_group_exporter_set_events (exporter, action_name, event_mask);
 272 }
 273
 274 static void
 275 g_action_group_exporter_action_removed (GActionGroup *action_group,
 276                                         const gchar  *action_name,
 277                                         gpointer      user_data)
 278 {
 279   GActionGroupExporter *exporter = user_data;
 280   guint event_mask;
 281
 282   event_mask = g_action_group_exporter_get_events (exporter, action_name);
 283
 284   /* If the add event for this is still queued then just cancel it since
 285    * it's gone now.
 286    *
 287    * If the event was freshly added, there should not have been any
 288    * enabled or state changed events.
 289    */
 290   if (event_mask & ACTION_ADDED_EVENT)
 291     {
 292       g_assert (~event_mask & ~(ACTION_STATE_CHANGED_EVENT | ACTION_ENABLED_CHANGED_EVENT));
 293       event_mask &= ~ACTION_ADDED_EVENT;
 294     }
 295
 296   /* Otherwise, queue a remove event.  Drop any state or enabled changes
 297    * that were queued before the remove. */
 298   else
 299     {
 300       event_mask |= ACTION_REMOVED_EVENT;
 301       event_mask &= ~(ACTION_STATE_CHANGED_EVENT | ACTION_ENABLED_CHANGED_EVENT);
 302     }
 303
 304   g_action_group_exporter_set_events (exporter, action_name, event_mask);
 305 }
 306
 307 static void
 308 g_action_group_exporter_action_state_changed (GActionGroup *action_group,
 309                                               const gchar  *action_name,
 310                                               GVariant     *value,
 311                                               gpointer      user_data)
 312 {
 313   GActionGroupExporter *exporter = user_data;
 314   guint event_mask;
 315
 316   event_mask = g_action_group_exporter_get_events (exporter, action_name);
 317
 318   /* If it was removed, it must have been added back.  Otherwise, why
 319    * are we hearing about changes?
 320    */
 321   g_assert (~event_mask & ACTION_REMOVED_EVENT ||
 322             event_mask & ACTION_ADDED_EVENT);
 323
 324   /* If it is freshly added, don't also bother with the state change
 325    * signal since the updated state will be sent as part of the pending
 326    * add message.
 327    */
 328   if (~event_mask & ACTION_ADDED_EVENT)
 329     event_mask |= ACTION_STATE_CHANGED_EVENT;
 330
 331   g_action_group_exporter_set_events (exporter, action_name, event_mask);
 332 }
 333
 334 static void
 335 g_action_group_exporter_action_enabled_changed (GActionGroup *action_group,
 336                                                 const gchar  *action_name,
 337                                                 gboolean      enabled,
 338                                                 gpointer      user_data)
 339 {
 340   GActionGroupExporter *exporter = user_data;
 341   guint event_mask;
 342
 343   event_mask = g_action_group_exporter_get_events (exporter, action_name);
 344
 345   /* Reasoning as above. */
 346   g_assert (~event_mask & ACTION_REMOVED_EVENT ||
 347             event_mask & ACTION_ADDED_EVENT);
 348
 349   if (~event_mask & ACTION_ADDED_EVENT)
 350     event_mask |= ACTION_ENABLED_CHANGED_EVENT;
 351
 352   g_action_group_exporter_set_events (exporter, action_name, event_mask);
 353 }
 354
 355 static void
 356 org_gtk_Actions_method_call (GDBusConnection       *connection,
 357                              const gchar           *sender,
 358                              const gchar           *object_path,
 359                              const gchar           *interface_name,
 360                              const gchar           *method_name,
 361                              GVariant              *parameters,
 362                              GDBusMethodInvocation *invocation,
 363                              gpointer               user_data)
 364 {
 365   GActionGroupExporter *exporter = user_data;
 366   GVariant *result = NULL;
 367
 368   if (g_str_equal (method_name, "List"))
 369     {
 370       gchar **list;
 371
 372       list = g_action_group_list_actions (exporter->action_group);
 373       result = g_variant_new ("(^as)", list);
 374       g_strfreev (list);
 375     }
 376
 377   else if (g_str_equal (method_name, "Describe"))
 378     {
 379       const gchar *name;
 380       GVariant *desc;
 381
 382       g_variant_get (parameters, "(&s)", &name);
 383
 384       if (!g_action_group_has_action (exporter->action_group, name))
 385         {
 386           g_dbus_method_invocation_return_error (invocation, G_DBUS_ERROR, G_DBUS_ERROR_INVALID_ARGS,
 387                                                  "The named action ('%s') does not exist.", name);
 388           return;
 389         }
 390
 391       desc = g_action_group_describe_action (exporter->action_group, name);
 392       result = g_variant_new ("(@(bgav))", desc);
 393     }
 394
 395   else if (g_str_equal (method_name, "DescribeAll"))
 396     {
 397       GVariantBuilder builder;
 398       gchar **list;
 399       gint i;
 400
 401       list = g_action_group_list_actions (exporter->action_group);
 402       g_variant_builder_init (&builder, G_VARIANT_TYPE ("a{s(bgav)}"));
 403       for (i = 0; list[i]; i++)
 404         {
 405           const gchar *name = list[i];
 406           GVariant *description;
 407
 408           description = g_action_group_describe_action (exporter->action_group, name);
 409           g_variant_builder_add (&builder, "{s@(bgav)}", name, description);
 410         }
 411       result = g_variant_new ("(a{s(bgav)})", &builder);
 412       g_strfreev (list);
 413     }
 414
 415   else if (g_str_equal (method_name, "Activate"))
 416     {
 417       GVariant *parameter = NULL;
 418       GVariant *platform_data;
 419       GVariantIter *iter;
 420       const gchar *name;
 421
 422       g_variant_get (parameters, "(&sav@a{sv})", &name, &iter, &platform_data);
 423       g_variant_iter_next (iter, "v", &parameter);
 424       g_variant_iter_free (iter);
 425
 426       if (G_IS_REMOTE_ACTION_GROUP (exporter->action_group))
 427         g_remote_action_group_activate_action_full (G_REMOTE_ACTION_GROUP (exporter->action_group),
 428                                                     name, parameter, platform_data);
 429       else
 430         g_action_group_activate_action (exporter->action_group, name, parameter);
 431
 432       if (parameter)
 433         g_variant_unref (parameter);
 434
 435       g_variant_unref (platform_data);
 436     }
 437
 438   else if (g_str_equal (method_name, "SetState"))
 439     {
 440       GVariant *platform_data;
 441       const gchar *name;
 442       GVariant *state;
 443
 444       g_variant_get (parameters, "(&sv@a{sv})", &name, &state, &platform_data);
 445
 446       if (G_IS_REMOTE_ACTION_GROUP (exporter->action_group))
 447         g_remote_action_group_change_action_state_full (G_REMOTE_ACTION_GROUP (exporter->action_group),
 448                                                         name, state, platform_data);
 449       else
 450         g_action_group_change_action_state (exporter->action_group, name, state);
 451
 452       g_variant_unref (platform_data);
 453       g_variant_unref (state);
 454     }
 455
 456   else
 457     g_assert_not_reached ();
 458
 459   g_dbus_method_invocation_return_value (invocation, result);
 460 }
 461
 462 static void
 463 g_action_group_exporter_free (gpointer user_data)
 464 {
 465   GActionGroupExporter *exporter = user_data;
 466
 467   g_signal_handlers_disconnect_by_func (exporter->action_group,
 468                                         g_action_group_exporter_action_added, exporter);
 469   g_signal_handlers_disconnect_by_func (exporter->action_group,
 470                                         g_action_group_exporter_action_enabled_changed, exporter);
 471   g_signal_handlers_disconnect_by_func (exporter->action_group,
 472                                         g_action_group_exporter_action_state_changed, exporter);
 473   g_signal_handlers_disconnect_by_func (exporter->action_group,
 474                                         g_action_group_exporter_action_removed, exporter);
 475
 476   g_hash_table_unref (exporter->pending_changes);
 477   if (exporter->pending_source)
 478     g_source_destroy (exporter->pending_source);
 479
 480   g_main_context_unref (exporter->context);
 481   g_object_unref (exporter->connection);
 482   g_object_unref (exporter->action_group);
 483   g_free (exporter->object_path);
 484
 485   g_slice_free (GActionGroupExporter, exporter);
 486 }
 487
 488 /**
 489  * g_dbus_connection_export_action_group:
 490  * @connection: a #GDBusConnection
 491  * @object_path: a D-Bus object path
 492  * @action_group: a #GActionGroup
 493  * @error: a pointer to a %NULL #GError, or %NULL
 494  *
 495  * Exports @action_group on @connection at @object_path.
 496  *
 497  * The implemented D-Bus API should be considered private.  It is
 498  * subject to change in the future.
 499  *
 500  * A given object path can only have one action group exported on it.
 501  * If this constraint is violated, the export will fail and 0 will be
 502  * returned (with @error set accordingly).
 503  *
 504  * You can unexport the action group using
 505  * g_dbus_connection_unexport_action_group() with the return value of
 506  * this function.
 507  *
 508  * The thread default main context is taken at the time of this call.
 509  * All incoming action activations and state change requests are
 510  * reported from this context.  Any changes on the action group that
 511  * cause it to emit signals must also come from this same context.
 512  * Since incoming action activations and state change requests are
 513  * rather likely to cause changes on the action group, this effectively
 514  * limits a given action group to being exported from only one main
 515  * context.
 516  *
 517  * Returns: the ID of the export (never zero), or 0 in case of failure
 518  *
 519  * Since: 2.32
 520  **/
 521 guint
 522 g_dbus_connection_export_action_group (GDBusConnection  *connection,
 523                                        const gchar      *object_path,
 524                                        GActionGroup     *action_group,
 525                                        GError          **error)
 526 {
 527   const GDBusInterfaceVTable vtable = {
 528     org_gtk_Actions_method_call
 529   };
 530   GActionGroupExporter *exporter;
 531   guint id;
 532
 533   if G_UNLIKELY (org_gtk_Actions == NULL)
 534     {
 535       GError *error = NULL;
 536       GDBusNodeInfo *info;
 537
 538       info = g_dbus_node_info_new_for_xml (org_gtk_Actions_xml, &error);
 539       if G_UNLIKELY (info == NULL)
 540         g_error ("%s", error->message);
 541       org_gtk_Actions = g_dbus_node_info_lookup_interface (info, "org.gtk.Actions");
 542       g_assert (org_gtk_Actions != NULL);
 543       g_dbus_interface_info_ref (org_gtk_Actions);
 544       g_dbus_node_info_unref (info);
 545     }
 546
 547   exporter = g_slice_new (GActionGroupExporter);
 548   id = g_dbus_connection_register_object (connection, object_path, org_gtk_Actions, &vtable,
 549                                           exporter, g_action_group_exporter_free, error);
 550
 551   if (id == 0)
 552     {
 553       g_slice_free (GActionGroupExporter, exporter);
 554       return 0;
 555     }
 556
 557   exporter->context = g_main_context_ref_thread_default ();
 558   exporter->pending_changes = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, NULL);
 559   exporter->pending_source = NULL;
 560   exporter->action_group = g_object_ref (action_group);
 561   exporter->connection = g_object_ref (connection);
 562   exporter->object_path = g_strdup (object_path);
 563
 564   g_signal_connect (action_group, "action-added",
 565                     G_CALLBACK (g_action_group_exporter_action_added), exporter);
 566   g_signal_connect (action_group, "action-removed",
 567                     G_CALLBACK (g_action_group_exporter_action_removed), exporter);
 568   g_signal_connect (action_group, "action-state-changed",
 569                     G_CALLBACK (g_action_group_exporter_action_state_changed), exporter);
 570   g_signal_connect (action_group, "action-enabled-changed",
 571                     G_CALLBACK (g_action_group_exporter_action_enabled_changed), exporter);
 572
 573   return id;
 574 }
 575
 576 /**
 577  * g_dbus_connection_unexport_action_group:
 578  * @connection: a #GDBusConnection
 579  * @export_id: the ID from g_dbus_connection_export_action_group()
 580  *
 581  * Reverses the effect of a previous call to
 582  * g_dbus_connection_export_action_group().
 583  *
 584  * It is an error to call this function with an ID that wasn't returned
 585  * from g_dbus_connection_export_action_group() or to call it with the
 586  * same ID more than once.
 587  *
 588  * Since: 2.32
 589  **/
 590 void
 591 g_dbus_connection_unexport_action_group (GDBusConnection *connection,
 592                                          guint            export_id)
 593 {
 594   g_dbus_connection_unregister_object (connection, export_id);
 595 }