1/* GDBus - GLib D-Bus Library
2 *
3 * Copyright (C) 2008-2010 Red Hat, Inc.
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2.1 of the License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General
16 * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
17 *
18 * Author: David Zeuthen <davidz@redhat.com>
19 */
20
21#ifndef __G_DBUS_CONNECTION_H__
22#define __G_DBUS_CONNECTION_H__
23
24#if !defined (__GIO_GIO_H_INSIDE__) && !defined (GIO_COMPILATION)
25#error "Only <gio/gio.h> can be included directly."
26#endif
27
28#include <gio/giotypes.h>
29
30G_BEGIN_DECLS
31
32#define G_TYPE_DBUS_CONNECTION (g_dbus_connection_get_type ())
33#define G_DBUS_CONNECTION(o) (G_TYPE_CHECK_INSTANCE_CAST ((o), G_TYPE_DBUS_CONNECTION, GDBusConnection))
34#define G_IS_DBUS_CONNECTION(o) (G_TYPE_CHECK_INSTANCE_TYPE ((o), G_TYPE_DBUS_CONNECTION))
35
36GLIB_AVAILABLE_IN_ALL
37GType g_dbus_connection_get_type (void) G_GNUC_CONST;
38
39/* ---------------------------------------------------------------------------------------------------- */
40
41GLIB_AVAILABLE_IN_ALL
42void g_bus_get (GBusType bus_type,
43 GCancellable *cancellable,
44 GAsyncReadyCallback callback,
45 gpointer user_data);
46GLIB_AVAILABLE_IN_ALL
47GDBusConnection *g_bus_get_finish (GAsyncResult *res,
48 GError **error);
49GLIB_AVAILABLE_IN_ALL
50GDBusConnection *g_bus_get_sync (GBusType bus_type,
51 GCancellable *cancellable,
52 GError **error);
53
54/* ---------------------------------------------------------------------------------------------------- */
55
56GLIB_AVAILABLE_IN_ALL
57void g_dbus_connection_new (GIOStream *stream,
58 const gchar *guid,
59 GDBusConnectionFlags flags,
60 GDBusAuthObserver *observer,
61 GCancellable *cancellable,
62 GAsyncReadyCallback callback,
63 gpointer user_data);
64GLIB_AVAILABLE_IN_ALL
65GDBusConnection *g_dbus_connection_new_finish (GAsyncResult *res,
66 GError **error);
67GLIB_AVAILABLE_IN_ALL
68GDBusConnection *g_dbus_connection_new_sync (GIOStream *stream,
69 const gchar *guid,
70 GDBusConnectionFlags flags,
71 GDBusAuthObserver *observer,
72 GCancellable *cancellable,
73 GError **error);
74
75GLIB_AVAILABLE_IN_ALL
76void g_dbus_connection_new_for_address (const gchar *address,
77 GDBusConnectionFlags flags,
78 GDBusAuthObserver *observer,
79 GCancellable *cancellable,
80 GAsyncReadyCallback callback,
81 gpointer user_data);
82GLIB_AVAILABLE_IN_ALL
83GDBusConnection *g_dbus_connection_new_for_address_finish (GAsyncResult *res,
84 GError **error);
85GLIB_AVAILABLE_IN_ALL
86GDBusConnection *g_dbus_connection_new_for_address_sync (const gchar *address,
87 GDBusConnectionFlags flags,
88 GDBusAuthObserver *observer,
89 GCancellable *cancellable,
90 GError **error);
91
92/* ---------------------------------------------------------------------------------------------------- */
93
94GLIB_AVAILABLE_IN_ALL
95void g_dbus_connection_start_message_processing (GDBusConnection *connection);
96GLIB_AVAILABLE_IN_ALL
97gboolean g_dbus_connection_is_closed (GDBusConnection *connection);
98GLIB_AVAILABLE_IN_ALL
99GIOStream *g_dbus_connection_get_stream (GDBusConnection *connection);
100GLIB_AVAILABLE_IN_ALL
101const gchar *g_dbus_connection_get_guid (GDBusConnection *connection);
102GLIB_AVAILABLE_IN_ALL
103const gchar *g_dbus_connection_get_unique_name (GDBusConnection *connection);
104GLIB_AVAILABLE_IN_ALL
105GCredentials *g_dbus_connection_get_peer_credentials (GDBusConnection *connection);
106
107GLIB_AVAILABLE_IN_2_34
108guint32 g_dbus_connection_get_last_serial (GDBusConnection *connection);
109
110GLIB_AVAILABLE_IN_ALL
111gboolean g_dbus_connection_get_exit_on_close (GDBusConnection *connection);
112GLIB_AVAILABLE_IN_ALL
113void g_dbus_connection_set_exit_on_close (GDBusConnection *connection,
114 gboolean exit_on_close);
115GLIB_AVAILABLE_IN_ALL
116GDBusCapabilityFlags g_dbus_connection_get_capabilities (GDBusConnection *connection);
117
118/* ---------------------------------------------------------------------------------------------------- */
119
120GLIB_AVAILABLE_IN_ALL
121void g_dbus_connection_close (GDBusConnection *connection,
122 GCancellable *cancellable,
123 GAsyncReadyCallback callback,
124 gpointer user_data);
125GLIB_AVAILABLE_IN_ALL
126gboolean g_dbus_connection_close_finish (GDBusConnection *connection,
127 GAsyncResult *res,
128 GError **error);
129GLIB_AVAILABLE_IN_ALL
130gboolean g_dbus_connection_close_sync (GDBusConnection *connection,
131 GCancellable *cancellable,
132 GError **error);
133
134/* ---------------------------------------------------------------------------------------------------- */
135
136GLIB_AVAILABLE_IN_ALL
137void g_dbus_connection_flush (GDBusConnection *connection,
138 GCancellable *cancellable,
139 GAsyncReadyCallback callback,
140 gpointer user_data);
141GLIB_AVAILABLE_IN_ALL
142gboolean g_dbus_connection_flush_finish (GDBusConnection *connection,
143 GAsyncResult *res,
144 GError **error);
145GLIB_AVAILABLE_IN_ALL
146gboolean g_dbus_connection_flush_sync (GDBusConnection *connection,
147 GCancellable *cancellable,
148 GError **error);
149
150/* ---------------------------------------------------------------------------------------------------- */
151
152GLIB_AVAILABLE_IN_ALL
153gboolean g_dbus_connection_send_message (GDBusConnection *connection,
154 GDBusMessage *message,
155 GDBusSendMessageFlags flags,
156 volatile guint32 *out_serial,
157 GError **error);
158GLIB_AVAILABLE_IN_ALL
159void g_dbus_connection_send_message_with_reply (GDBusConnection *connection,
160 GDBusMessage *message,
161 GDBusSendMessageFlags flags,
162 gint timeout_msec,
163 volatile guint32 *out_serial,
164 GCancellable *cancellable,
165 GAsyncReadyCallback callback,
166 gpointer user_data);
167GLIB_AVAILABLE_IN_ALL
168GDBusMessage *g_dbus_connection_send_message_with_reply_finish (GDBusConnection *connection,
169 GAsyncResult *res,
170 GError **error);
171GLIB_AVAILABLE_IN_ALL
172GDBusMessage *g_dbus_connection_send_message_with_reply_sync (GDBusConnection *connection,
173 GDBusMessage *message,
174 GDBusSendMessageFlags flags,
175 gint timeout_msec,
176 volatile guint32 *out_serial,
177 GCancellable *cancellable,
178 GError **error);
179
180/* ---------------------------------------------------------------------------------------------------- */
181
182GLIB_AVAILABLE_IN_ALL
183gboolean g_dbus_connection_emit_signal (GDBusConnection *connection,
184 const gchar *destination_bus_name,
185 const gchar *object_path,
186 const gchar *interface_name,
187 const gchar *signal_name,
188 GVariant *parameters,
189 GError **error);
190GLIB_AVAILABLE_IN_ALL
191void g_dbus_connection_call (GDBusConnection *connection,
192 const gchar *bus_name,
193 const gchar *object_path,
194 const gchar *interface_name,
195 const gchar *method_name,
196 GVariant *parameters,
197 const GVariantType *reply_type,
198 GDBusCallFlags flags,
199 gint timeout_msec,
200 GCancellable *cancellable,
201 GAsyncReadyCallback callback,
202 gpointer user_data);
203GLIB_AVAILABLE_IN_ALL
204GVariant *g_dbus_connection_call_finish (GDBusConnection *connection,
205 GAsyncResult *res,
206 GError **error);
207GLIB_AVAILABLE_IN_ALL
208GVariant *g_dbus_connection_call_sync (GDBusConnection *connection,
209 const gchar *bus_name,
210 const gchar *object_path,
211 const gchar *interface_name,
212 const gchar *method_name,
213 GVariant *parameters,
214 const GVariantType *reply_type,
215 GDBusCallFlags flags,
216 gint timeout_msec,
217 GCancellable *cancellable,
218 GError **error);
219GLIB_AVAILABLE_IN_2_30
220void g_dbus_connection_call_with_unix_fd_list (GDBusConnection *connection,
221 const gchar *bus_name,
222 const gchar *object_path,
223 const gchar *interface_name,
224 const gchar *method_name,
225 GVariant *parameters,
226 const GVariantType *reply_type,
227 GDBusCallFlags flags,
228 gint timeout_msec,
229 GUnixFDList *fd_list,
230 GCancellable *cancellable,
231 GAsyncReadyCallback callback,
232 gpointer user_data);
233GLIB_AVAILABLE_IN_2_30
234GVariant *g_dbus_connection_call_with_unix_fd_list_finish (GDBusConnection *connection,
235 GUnixFDList **out_fd_list,
236 GAsyncResult *res,
237 GError **error);
238GLIB_AVAILABLE_IN_2_30
239GVariant *g_dbus_connection_call_with_unix_fd_list_sync (GDBusConnection *connection,
240 const gchar *bus_name,
241 const gchar *object_path,
242 const gchar *interface_name,
243 const gchar *method_name,
244 GVariant *parameters,
245 const GVariantType *reply_type,
246 GDBusCallFlags flags,
247 gint timeout_msec,
248 GUnixFDList *fd_list,
249 GUnixFDList **out_fd_list,
250 GCancellable *cancellable,
251 GError **error);
252
253/* ---------------------------------------------------------------------------------------------------- */
254
255
256/**
257 * GDBusInterfaceMethodCallFunc:
258 * @connection: A #GDBusConnection.
259 * @sender: The unique bus name of the remote caller.
260 * @object_path: The object path that the method was invoked on.
261 * @interface_name: The D-Bus interface name the method was invoked on.
262 * @method_name: The name of the method that was invoked.
263 * @parameters: A #GVariant tuple with parameters.
264 * @invocation: (transfer full): A #GDBusMethodInvocation object that must be used to return a value or error.
265 * @user_data: The @user_data #gpointer passed to g_dbus_connection_register_object().
266 *
267 * The type of the @method_call function in #GDBusInterfaceVTable.
268 *
269 * Since: 2.26
270 */
271typedef void (*GDBusInterfaceMethodCallFunc) (GDBusConnection *connection,
272 const gchar *sender,
273 const gchar *object_path,
274 const gchar *interface_name,
275 const gchar *method_name,
276 GVariant *parameters,
277 GDBusMethodInvocation *invocation,
278 gpointer user_data);
279
280/**
281 * GDBusInterfaceGetPropertyFunc:
282 * @connection: A #GDBusConnection.
283 * @sender: The unique bus name of the remote caller.
284 * @object_path: The object path that the method was invoked on.
285 * @interface_name: The D-Bus interface name for the property.
286 * @property_name: The name of the property to get the value of.
287 * @error: Return location for error.
288 * @user_data: The @user_data #gpointer passed to g_dbus_connection_register_object().
289 *
290 * The type of the @get_property function in #GDBusInterfaceVTable.
291 *
292 * Returns: A #GVariant with the value for @property_name or %NULL if
293 * @error is set. If the returned #GVariant is floating, it is
294 * consumed - otherwise its reference count is decreased by one.
295 *
296 * Since: 2.26
297 */
298typedef GVariant *(*GDBusInterfaceGetPropertyFunc) (GDBusConnection *connection,
299 const gchar *sender,
300 const gchar *object_path,
301 const gchar *interface_name,
302 const gchar *property_name,
303 GError **error,
304 gpointer user_data);
305
306/**
307 * GDBusInterfaceSetPropertyFunc:
308 * @connection: A #GDBusConnection.
309 * @sender: The unique bus name of the remote caller.
310 * @object_path: The object path that the method was invoked on.
311 * @interface_name: The D-Bus interface name for the property.
312 * @property_name: The name of the property to get the value of.
313 * @value: The value to set the property to.
314 * @error: Return location for error.
315 * @user_data: The @user_data #gpointer passed to g_dbus_connection_register_object().
316 *
317 * The type of the @set_property function in #GDBusInterfaceVTable.
318 *
319 * Returns: %TRUE if the property was set to @value, %FALSE if @error is set.
320 *
321 * Since: 2.26
322 */
323typedef gboolean (*GDBusInterfaceSetPropertyFunc) (GDBusConnection *connection,
324 const gchar *sender,
325 const gchar *object_path,
326 const gchar *interface_name,
327 const gchar *property_name,
328 GVariant *value,
329 GError **error,
330 gpointer user_data);
331
332/**
333 * GDBusInterfaceVTable:
334 * @method_call: Function for handling incoming method calls.
335 * @get_property: Function for getting a property.
336 * @set_property: Function for setting a property.
337 *
338 * Virtual table for handling properties and method calls for a D-Bus
339 * interface.
340 *
341 * Since 2.38, if you want to handle getting/setting D-Bus properties
342 * asynchronously, give %NULL as your get_property() or set_property()
343 * function. The D-Bus call will be directed to your @method_call function,
344 * with the provided @interface_name set to "org.freedesktop.DBus.Properties".
345 *
346 * Ownership of the #GDBusMethodInvocation object passed to the
347 * method_call() function is transferred to your handler; you must
348 * call one of the methods of #GDBusMethodInvocation to return a reply
349 * (possibly empty), or an error. These functions also take ownership
350 * of the passed-in invocation object, so unless the invocation
351 * object has otherwise been referenced, it will be then be freed.
352 * Calling one of these functions may be done within your
353 * method_call() implementation but it also can be done at a later
354 * point to handle the method asynchronously.
355 *
356 * The usual checks on the validity of the calls is performed. For
357 * `Get` calls, an error is automatically returned if the property does
358 * not exist or the permissions do not allow access. The same checks are
359 * performed for `Set` calls, and the provided value is also checked for
360 * being the correct type.
361 *
362 * For both `Get` and `Set` calls, the #GDBusMethodInvocation
363 * passed to the @method_call handler can be queried with
364 * g_dbus_method_invocation_get_property_info() to get a pointer
365 * to the #GDBusPropertyInfo of the property.
366 *
367 * If you have readable properties specified in your interface info,
368 * you must ensure that you either provide a non-%NULL @get_property()
369 * function or provide implementations of both the `Get` and `GetAll`
370 * methods on org.freedesktop.DBus.Properties interface in your @method_call
371 * function. Note that the required return type of the `Get` call is
372 * `(v)`, not the type of the property. `GetAll` expects a return value
373 * of type `a{sv}`.
374 *
375 * If you have writable properties specified in your interface info,
376 * you must ensure that you either provide a non-%NULL @set_property()
377 * function or provide an implementation of the `Set` call. If implementing
378 * the call, you must return the value of type %G_VARIANT_TYPE_UNIT.
379 *
380 * Since: 2.26
381 */
382struct _GDBusInterfaceVTable
383{
384 GDBusInterfaceMethodCallFunc method_call;
385 GDBusInterfaceGetPropertyFunc get_property;
386 GDBusInterfaceSetPropertyFunc set_property;
387
388 /*< private >*/
389 /* Padding for future expansion - also remember to update
390 * gdbusconnection.c:_g_dbus_interface_vtable_copy() when
391 * changing this.
392 */
393 gpointer padding[8];
394};
395
396GLIB_AVAILABLE_IN_ALL
397guint g_dbus_connection_register_object (GDBusConnection *connection,
398 const gchar *object_path,
399 GDBusInterfaceInfo *interface_info,
400 const GDBusInterfaceVTable *vtable,
401 gpointer user_data,
402 GDestroyNotify user_data_free_func,
403 GError **error);
404GLIB_AVAILABLE_IN_2_46
405guint g_dbus_connection_register_object_with_closures (GDBusConnection *connection,
406 const gchar *object_path,
407 GDBusInterfaceInfo *interface_info,
408 GClosure *method_call_closure,
409 GClosure *get_property_closure,
410 GClosure *set_property_closure,
411 GError **error);
412GLIB_AVAILABLE_IN_ALL
413gboolean g_dbus_connection_unregister_object (GDBusConnection *connection,
414 guint registration_id);
415
416/* ---------------------------------------------------------------------------------------------------- */
417
418/**
419 * GDBusSubtreeEnumerateFunc:
420 * @connection: A #GDBusConnection.
421 * @sender: The unique bus name of the remote caller.
422 * @object_path: The object path that was registered with g_dbus_connection_register_subtree().
423 * @user_data: The @user_data #gpointer passed to g_dbus_connection_register_subtree().
424 *
425 * The type of the @enumerate function in #GDBusSubtreeVTable.
426 *
427 * This function is called when generating introspection data and also
428 * when preparing to dispatch incoming messages in the event that the
429 * %G_DBUS_SUBTREE_FLAGS_DISPATCH_TO_UNENUMERATED_NODES flag is not
430 * specified (ie: to verify that the object path is valid).
431 *
432 * Hierarchies are not supported; the items that you return should not
433 * contain the '/' character.
434 *
435 * The return value will be freed with g_strfreev().
436 *
437 * Returns: A newly allocated array of strings for node names that are children of @object_path.
438 *
439 * Since: 2.26
440 */
441typedef gchar** (*GDBusSubtreeEnumerateFunc) (GDBusConnection *connection,
442 const gchar *sender,
443 const gchar *object_path,
444 gpointer user_data);
445
446/**
447 * GDBusSubtreeIntrospectFunc:
448 * @connection: A #GDBusConnection.
449 * @sender: The unique bus name of the remote caller.
450 * @object_path: The object path that was registered with g_dbus_connection_register_subtree().
451 * @node: A node that is a child of @object_path (relative to @object_path) or %NULL for the root of the subtree.
452 * @user_data: The @user_data #gpointer passed to g_dbus_connection_register_subtree().
453 *
454 * The type of the @introspect function in #GDBusSubtreeVTable.
455 *
456 * Subtrees are flat. @node, if non-%NULL, is always exactly one
457 * segment of the object path (ie: it never contains a slash).
458 *
459 * This function should return %NULL to indicate that there is no object
460 * at this node.
461 *
462 * If this function returns non-%NULL, the return value is expected to
463 * be a %NULL-terminated array of pointers to #GDBusInterfaceInfo
464 * structures describing the interfaces implemented by @node. This
465 * array will have g_dbus_interface_info_unref() called on each item
466 * before being freed with g_free().
467 *
468 * The difference between returning %NULL and an array containing zero
469 * items is that the standard DBus interfaces will returned to the
470 * remote introspector in the empty array case, but not in the %NULL
471 * case.
472 *
473 * Returns: A %NULL-terminated array of pointers to #GDBusInterfaceInfo, or %NULL.
474 *
475 * Since: 2.26
476 */
477typedef GDBusInterfaceInfo ** (*GDBusSubtreeIntrospectFunc) (GDBusConnection *connection,
478 const gchar *sender,
479 const gchar *object_path,
480 const gchar *node,
481 gpointer user_data);
482
483/**
484 * GDBusSubtreeDispatchFunc:
485 * @connection: A #GDBusConnection.
486 * @sender: The unique bus name of the remote caller.
487 * @object_path: The object path that was registered with g_dbus_connection_register_subtree().
488 * @interface_name: The D-Bus interface name that the method call or property access is for.
489 * @node: A node that is a child of @object_path (relative to @object_path) or %NULL for the root of the subtree.
490 * @out_user_data: (nullable) (not optional): Return location for user data to pass to functions in the returned #GDBusInterfaceVTable (never %NULL).
491 * @user_data: The @user_data #gpointer passed to g_dbus_connection_register_subtree().
492 *
493 * The type of the @dispatch function in #GDBusSubtreeVTable.
494 *
495 * Subtrees are flat. @node, if non-%NULL, is always exactly one
496 * segment of the object path (ie: it never contains a slash).
497 *
498 * Returns: A #GDBusInterfaceVTable or %NULL if you don't want to handle the methods.
499 *
500 * Since: 2.26
501 */
502typedef const GDBusInterfaceVTable * (*GDBusSubtreeDispatchFunc) (GDBusConnection *connection,
503 const gchar *sender,
504 const gchar *object_path,
505 const gchar *interface_name,
506 const gchar *node,
507 gpointer *out_user_data,
508 gpointer user_data);
509
510/**
511 * GDBusSubtreeVTable:
512 * @enumerate: Function for enumerating child nodes.
513 * @introspect: Function for introspecting a child node.
514 * @dispatch: Function for dispatching a remote call on a child node.
515 *
516 * Virtual table for handling subtrees registered with g_dbus_connection_register_subtree().
517 *
518 * Since: 2.26
519 */
520struct _GDBusSubtreeVTable
521{
522 GDBusSubtreeEnumerateFunc enumerate;
523 GDBusSubtreeIntrospectFunc introspect;
524 GDBusSubtreeDispatchFunc dispatch;
525
526 /*< private >*/
527 /* Padding for future expansion - also remember to update
528 * gdbusconnection.c:_g_dbus_subtree_vtable_copy() when
529 * changing this.
530 */
531 gpointer padding[8];
532};
533
534GLIB_AVAILABLE_IN_ALL
535guint g_dbus_connection_register_subtree (GDBusConnection *connection,
536 const gchar *object_path,
537 const GDBusSubtreeVTable *vtable,
538 GDBusSubtreeFlags flags,
539 gpointer user_data,
540 GDestroyNotify user_data_free_func,
541 GError **error);
542GLIB_AVAILABLE_IN_ALL
543gboolean g_dbus_connection_unregister_subtree (GDBusConnection *connection,
544 guint registration_id);
545
546/* ---------------------------------------------------------------------------------------------------- */
547
548/**
549 * GDBusSignalCallback:
550 * @connection: A #GDBusConnection.
551 * @sender_name: The unique bus name of the sender of the signal.
552 * @object_path: The object path that the signal was emitted on.
553 * @interface_name: The name of the interface.
554 * @signal_name: The name of the signal.
555 * @parameters: A #GVariant tuple with parameters for the signal.
556 * @user_data: User data passed when subscribing to the signal.
557 *
558 * Signature for callback function used in g_dbus_connection_signal_subscribe().
559 *
560 * Since: 2.26
561 */
562typedef void (*GDBusSignalCallback) (GDBusConnection *connection,
563 const gchar *sender_name,
564 const gchar *object_path,
565 const gchar *interface_name,
566 const gchar *signal_name,
567 GVariant *parameters,
568 gpointer user_data);
569
570GLIB_AVAILABLE_IN_ALL
571guint g_dbus_connection_signal_subscribe (GDBusConnection *connection,
572 const gchar *sender,
573 const gchar *interface_name,
574 const gchar *member,
575 const gchar *object_path,
576 const gchar *arg0,
577 GDBusSignalFlags flags,
578 GDBusSignalCallback callback,
579 gpointer user_data,
580 GDestroyNotify user_data_free_func);
581GLIB_AVAILABLE_IN_ALL
582void g_dbus_connection_signal_unsubscribe (GDBusConnection *connection,
583 guint subscription_id);
584
585/* ---------------------------------------------------------------------------------------------------- */
586
587/**
588 * GDBusMessageFilterFunction:
589 * @connection: (transfer none): A #GDBusConnection.
590 * @message: (transfer full): A locked #GDBusMessage that the filter function takes ownership of.
591 * @incoming: %TRUE if it is a message received from the other peer, %FALSE if it is
592 * a message to be sent to the other peer.
593 * @user_data: User data passed when adding the filter.
594 *
595 * Signature for function used in g_dbus_connection_add_filter().
596 *
597 * A filter function is passed a #GDBusMessage and expected to return
598 * a #GDBusMessage too. Passive filter functions that don't modify the
599 * message can simply return the @message object:
600 * |[
601 * static GDBusMessage *
602 * passive_filter (GDBusConnection *connection
603 * GDBusMessage *message,
604 * gboolean incoming,
605 * gpointer user_data)
606 * {
607 * // inspect @message
608 * return message;
609 * }
610 * ]|
611 * Filter functions that wants to drop a message can simply return %NULL:
612 * |[
613 * static GDBusMessage *
614 * drop_filter (GDBusConnection *connection
615 * GDBusMessage *message,
616 * gboolean incoming,
617 * gpointer user_data)
618 * {
619 * if (should_drop_message)
620 * {
621 * g_object_unref (message);
622 * message = NULL;
623 * }
624 * return message;
625 * }
626 * ]|
627 * Finally, a filter function may modify a message by copying it:
628 * |[
629 * static GDBusMessage *
630 * modifying_filter (GDBusConnection *connection
631 * GDBusMessage *message,
632 * gboolean incoming,
633 * gpointer user_data)
634 * {
635 * GDBusMessage *copy;
636 * GError *error;
637 *
638 * error = NULL;
639 * copy = g_dbus_message_copy (message, &error);
640 * // handle @error being set
641 * g_object_unref (message);
642 *
643 * // modify @copy
644 *
645 * return copy;
646 * }
647 * ]|
648 * If the returned #GDBusMessage is different from @message and cannot
649 * be sent on @connection (it could use features, such as file
650 * descriptors, not compatible with @connection), then a warning is
651 * logged to standard error. Applications can
652 * check this ahead of time using g_dbus_message_to_blob() passing a
653 * #GDBusCapabilityFlags value obtained from @connection.
654 *
655 * Returns: (transfer full) (nullable): A #GDBusMessage that will be freed with
656 * g_object_unref() or %NULL to drop the message. Passive filter
657 * functions can simply return the passed @message object.
658 *
659 * Since: 2.26
660 */
661typedef GDBusMessage *(*GDBusMessageFilterFunction) (GDBusConnection *connection,
662 GDBusMessage *message,
663 gboolean incoming,
664 gpointer user_data);
665
666GLIB_AVAILABLE_IN_ALL
667guint g_dbus_connection_add_filter (GDBusConnection *connection,
668 GDBusMessageFilterFunction filter_function,
669 gpointer user_data,
670 GDestroyNotify user_data_free_func);
671
672GLIB_AVAILABLE_IN_ALL
673void g_dbus_connection_remove_filter (GDBusConnection *connection,
674 guint filter_id);
675
676/* ---------------------------------------------------------------------------------------------------- */
677
678
679G_END_DECLS
680
681#endif /* __G_DBUS_CONNECTION_H__ */
682