events: remove leading underscores
[vlc.git] / include / vlc_events.h
1 /*****************************************************************************
2  * events.h: events definitions
3  * Interface used to send events.
4  *****************************************************************************
5  * Copyright (C) 2007 the VideoLAN team
6  * $Id$
7  *
8  * Authors: Pierre d'Herbemont
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or
13  * (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
23  *****************************************************************************/
24
25 #ifndef VLC_EVENTS_H
26 # define VLC_EVENTS_H
27
28 #include <vlc_arrays.h>
29 #include <vlc_meta.h>
30
31 /**
32  * \file
33  * This file is the interface definition for events
34  * (implementation in src/misc/events.c)
35  */
36
37 /*****************************************************************************
38  * Documentation
39  *****************************************************************************/
40 /*
41  **** Background
42  *
43  * This implements a way to send and receive event for an object (which can be
44  * a simple C struct or less).
45  *
46  * This is in direct concurrency with the Variable based Callback
47  * (see src/misc/variables.c).
48  *
49  * It has the following advantages over Variable based Callback:
50  * - No need to implement the whole VLC_COMMON_MEMBERS in the object,
51  * thus it reduce it size. This is especially true for input_item_t which
52  * doesn't have VLC_COMMON_MEMBERS. This is the first reason of existence of
53  * this implementation.
54  * - Libvlc can easily be based upon that.
55  * - Existing event are clearly declared (in include/vlc_events.h)
56  *
57  *
58  **** Example usage
59  *
60  * (vlc_cool_object_t doesn't need to have the VLC_COMMON_MEMBERS.)
61  *
62  * struct vlc_cool_object_t
63  * {
64  *        ...
65  *        vlc_event_manager_t p_event_manager;
66  *        ...
67  * }
68  *
69  * vlc_my_cool_object_new()
70  * {
71  *        ...
72  *        vlc_event_manager_init( &p_self->p_event_manager, p_self, p_a_libvlc_object );
73  *        vlc_event_manager_register_event_type(p_self->p_event_manager,
74  *                vlc_MyCoolObjectDidSomething, p_e)
75  *        ...
76  * }
77  *
78  * vlc_my_cool_object_release()
79  * {
80  *         ...
81  *         vlc_event_manager_fini( &p_self->p_event_manager );
82  *         ...
83  * }
84  *
85  * vlc_my_cool_object_do_something()
86  * {
87  *        ...
88  *        vlc_event_t event;
89  *        event.type = vlc_MyCoolObjectDidSomething;
90  *        event.u.my_cool_object_did_something.what_it_did = kSomething;
91  *        vlc_event_send( &p_self->p_event_manager, &event );
92  * }
93  * */
94
95   /*****************************************************************************
96  * Event Type
97  *****************************************************************************/
98
99 /* Private structure defined in misc/events.c */
100 struct vlc_event_listeners_group_t;
101
102 /* Event manager type */
103 typedef struct vlc_event_manager_t
104 {
105     void * p_obj;
106     vlc_mutex_t object_lock;
107     vlc_mutex_t event_sending_lock;
108     vlc_object_t *p_parent_object;
109     DECL_ARRAY(struct vlc_event_listeners_group_t *) listeners_groups;
110 } vlc_event_manager_t;
111
112 /* List of event */
113 /* Be sure to keep sync-ed with misc/events.c debug name table */
114 typedef enum vlc_event_type_t {
115     /* Input (thread) events */
116     vlc_InputStateChanged,
117     vlc_InputSelectedStreamChanged,
118
119     /* Input item events */
120     vlc_InputItemMetaChanged,
121     vlc_InputItemSubItemAdded,
122     vlc_InputItemSubItemTreeAdded,
123     vlc_InputItemDurationChanged,
124     vlc_InputItemPreparsedChanged,
125     vlc_InputItemNameChanged,
126     vlc_InputItemInfoChanged,
127     vlc_InputItemErrorWhenReadingChanged,
128
129     /* Service Discovery event */
130     vlc_ServicesDiscoveryItemAdded,
131     vlc_ServicesDiscoveryItemRemoved,
132     vlc_ServicesDiscoveryStarted,
133     vlc_ServicesDiscoveryEnded
134 } vlc_event_type_t;
135
136 /* Event definition */
137 typedef struct vlc_event_t
138 {
139     vlc_event_type_t type;
140     void * p_obj; /* Sender object, automatically filled by vlc_event_send() */
141     union vlc_event_type_specific
142     {
143         /* Input (thread) events */
144         struct vlc_input_state_changed
145         {
146             int new_state;
147         } input_state_changed;
148         struct vlc_input_selected_stream_changed
149         {
150             void * unused;
151         } input_selected_stream_changed;
152
153         /* Input item events */
154         struct vlc_input_item_meta_changed
155         {
156             vlc_meta_type_t meta_type;
157         } input_item_meta_changed;
158         struct vlc_input_item_subitem_added
159         {
160             input_item_t * p_new_child;
161         } input_item_subitem_added;
162         struct vlc_input_item_subitem_tree_added
163         {
164             input_item_node_t * p_root;
165         } input_item_subitem_tree_added;
166         struct vlc_input_item_duration_changed
167         {
168             mtime_t new_duration;
169         } input_item_duration_changed;
170         struct vlc_input_item_preparsed_changed
171         {
172             int new_status;
173         } input_item_preparsed_changed;
174         struct vlc_input_item_name_changed
175         {
176             const char * new_name;
177         } input_item_name_changed;
178         struct vlc_input_item_info_changed
179         {
180             void * unused;
181         } input_item_info_changed;
182         struct input_item_error_when_reading_changed
183         {
184             bool new_value;
185         } input_item_error_when_reading_changed;
186
187         /* Service discovery events */
188         struct vlc_services_discovery_item_added
189         {
190             input_item_t * p_new_item;
191             const char * psz_category;
192         } services_discovery_item_added;
193         struct vlc_services_discovery_item_removed
194         {
195             input_item_t * p_item;
196         } services_discovery_item_removed;
197         struct vlc_services_discovery_started
198         {
199             void * unused;
200         } services_discovery_started;
201         struct vlc_services_discovery_ended
202         {
203             void * unused;
204         } services_discovery_ended;
205
206     } u;
207 } vlc_event_t;
208
209 /* Event callback type */
210 typedef void ( *vlc_event_callback_t )( const vlc_event_t *, void * );
211
212  /*****************************************************************************
213  * Event manager
214  *****************************************************************************/
215
216 /*
217  * p_obj points to the object that owns the event manager, and from
218  * which events are sent
219  * p_obj is here to give us a libvlc instance
220  */
221 #define vlc_event_manager_init_with_vlc_object(a,b) \
222             vlc_event_manager_init( a, b, b )
223
224 VLC_EXPORT(int, vlc_event_manager_init, ( vlc_event_manager_t * p_em,
225                                           void * p_obj, vlc_object_t * ));
226 #define vlc_event_manager_init(a,b,c) \
227             vlc_event_manager_init(a, b, VLC_OBJECT(c))
228
229 /*
230  * Destroy
231  */
232 VLC_EXPORT(void, vlc_event_manager_fini, ( vlc_event_manager_t * p_em ));
233
234 /*
235  * Tells a specific event manager that it will handle event_type object
236  */
237 VLC_EXPORT(int, vlc_event_manager_register_event_type,
238                 ( vlc_event_manager_t * p_em, vlc_event_type_t event_type ));
239
240 /*
241  * Send an event to the listener attached to this p_em.
242  */
243 VLC_EXPORT(void, vlc_event_send, ( vlc_event_manager_t * p_em,
244                                    vlc_event_t * p_event ));
245
246 /*
247  * Add a callback for an event.
248  */
249 VLC_EXPORT(int, vlc_event_attach, ( vlc_event_manager_t * p_event_manager,
250                                     vlc_event_type_t event_type,
251                                     vlc_event_callback_t pf_callback,
252                                     void *p_user_data,
253                                     const char * psz_debug_name ));
254 #define vlc_event_attach(a, b, c, d) vlc_event_attach(a, b, c, d, #c)
255
256 /*
257  * Remove a callback for an event.
258  */
259 VLC_EXPORT(int, vlc_event_detach, ( vlc_event_manager_t *p_event_manager,
260                                     vlc_event_type_t event_type,
261                                     vlc_event_callback_t pf_callback,
262                                     void *p_user_data ));
263
264 #endif /* VLC_EVENTS_H */