1#ifndef foosubscribehfoo
2#define foosubscribehfoo
3
4/***
5 This file is part of PulseAudio.
6
7 Copyright 2004-2006 Lennart Poettering
8 Copyright 2006 Pierre Ossman <ossman@cendio.se> for Cendio AB
9
10 PulseAudio is free software; you can redistribute it and/or modify
11 it under the terms of the GNU Lesser General Public License as published
12 by the Free Software Foundation; either version 2.1 of the License,
13 or (at your option) any later version.
14
15 PulseAudio is distributed in the hope that it will be useful, but
16 WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 General Public License for more details.
19
20 You should have received a copy of the GNU Lesser General Public License
21 along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
22***/
23
24#include <inttypes.h>
25
26#include <pulse/def.h>
27#include <pulse/context.h>
28#include <pulse/cdecl.h>
29#include <pulse/version.h>
30
31/** \page subscribe Event Subscription
32 *
33 * \section overv_sec Overview
34 *
35 * The application can be notified, asynchronously, whenever the internal
36 * layout of the server changes. Possible notifications are described in the
37 * \ref pa_subscription_event_type and \ref pa_subscription_mask
38 * enumerations.
39 *
40 * The application sets the notification mask using pa_context_subscribe()
41 * and the function that will be called whenever a notification occurs using
42 * pa_context_set_subscribe_callback().
43 *
44 * The callback will be called with a \ref pa_subscription_event_type_t
45 * representing the event that caused the callback. Clients can examine what
46 * object changed using \ref PA_SUBSCRIPTION_EVENT_FACILITY_MASK. The actual
47 * event type can then be extracted with \ref PA_SUBSCRIPTION_EVENT_TYPE_MASK.
48 * Please note that the masked values are integers, not flags (so you will
49 * check the object/event type using a comparison not a binary AND). For
50 * example, the callback might look something like:
51 *
52@verbatim
53void my_subscription_callback(pa_context *c, pa_subscription_event_type_t t,
54 uint32_t idx, void *userdata) {
55 if ((t & PA_SUBSCRIPTION_EVENT_FACILITY_MASK) == PA_SUBSCRIPTION_EVENT_SOURCE) {
56 if ((t & PA_SUBSCRIPTION_EVENT_TYPE_MASK) == PA_SUBSCRIPTION_EVENT_NEW) {
57 ... a source was added, let's do stuff! ...
58 }
59 }
60}
61@endverbatim
62 */
63
64/** \file
65 * Daemon introspection event subscription subsystem.
66 *
67 * See also \subpage subscribe
68 */
69
70PA_C_DECL_BEGIN
71
72/** Subscription event callback prototype */
73typedef void (*pa_context_subscribe_cb_t)(pa_context *c, pa_subscription_event_type_t t, uint32_t idx, void *userdata);
74
75/** Enable event notification */
76pa_operation* pa_context_subscribe(pa_context *c, pa_subscription_mask_t m, pa_context_success_cb_t cb, void *userdata);
77
78/** Set the context specific call back function that is called whenever the state of the daemon changes */
79void pa_context_set_subscribe_callback(pa_context *c, pa_context_subscribe_cb_t cb, void *userdata);
80
81PA_C_DECL_END
82
83#endif
84