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 (at) 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, write to the Free Software 22 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 23 USA. 24 ***/ 25 26 #include <inttypes.h> 27 28 #include <pulse/def.h> 29 #include <pulse/context.h> 30 #include <pulse/cdecl.h> 31 #include <pulse/version.h> 32 33 /** \page subscribe Event Subscription 34 * 35 * \section overv_sec Overview 36 * 37 * The application can be notified, asynchronously, whenever the internal 38 * layout of the server changes. Possible notifications are described in the 39 * \ref pa_subscription_event_type and \ref pa_subscription_mask 40 * enumerations. 41 * 42 * The application sets the notification mask using pa_context_subscribe() 43 * and the function that will be called whenever a notification occurs using 44 * pa_context_set_subscribe_callback(). 45 * 46 * The callback will be called with a \ref pa_subscription_event_type_t 47 * representing the event that caused the callback. Clients can examine what 48 * object changed using \ref PA_SUBSCRIPTION_EVENT_FACILITY_MASK. The actual 49 * event type can then be extracted with \ref PA_SUBSCRIPTION_EVENT_TYPE_MASK. 50 * Please note that the masked values are integers, not flags (so you will 51 * check the object/event type using a comparison not a binary AND). For 52 * example, the callback might look something like: 53 * 54 @verbatim 55 void my_subscription_callback(pa_context *c, pa_subscription_event_type_t t, 56 uint32_t idx, void *userdata) 57 { 58 if ((t & PA_SUBSCRIPTION_EVENT_FACILITY_MASK) == PA_SUBSCRIPTION_EVENT_SOURCE) { 59 if ((t & PA_SUBSCRIPTION_EVENT_TYPE_MASK) == PA_SUBSCRIPTION_EVENT_NEW) { 60 ... a source was added, let's do stuff! ... 61 } 62 } 63 } 64 @endverbatim 65 */ 66 67 /** \file 68 * Daemon introspection event subscription subsystem. 69 * 70 * See also \subpage subscribe 71 */ 72 73 PA_C_DECL_BEGIN 74 75 /** Subscription event callback prototype */ 76 typedef void (*pa_context_subscribe_cb_t)(pa_context *c, pa_subscription_event_type_t t, uint32_t idx, void *userdata); 77 78 /** Enable event notification */ 79 pa_operation* pa_context_subscribe(pa_context *c, pa_subscription_mask_t m, pa_context_success_cb_t cb, void *userdata); 80 81 /** Set the context specific call back function that is called whenever the state of the daemon changes */ 82 void pa_context_set_subscribe_callback(pa_context *c, pa_context_subscribe_cb_t cb, void *userdata); 83 84 PA_C_DECL_END 85 86 #endif 87
