lib/event.c

   1 /*****************************************************************************
   2  * event.c: New libvlc event control API
   3  *****************************************************************************
   4  * Copyright (C) 2007-2010 VLC authors and VideoLAN
   5  * $Id $
   6  *
   7  * Authors: Filippo Carone <filippo@carone.org>
   8  *          Pierre d'Herbemont <pdherbemont # videolan.org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify it
  11  * under the terms of the GNU Lesser General Public License as published by
  12  * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public License
  21  * along with this program; if not, write to the Free Software Foundation,
  22  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  23  *****************************************************************************/
  24
  25 #ifdef HAVE_CONFIG_H
  26 # include "config.h"
  27 #endif
  28
  29 #include <assert.h>
  30 #include <errno.h>
  31
  32 #include <vlc/libvlc.h>
  33 #include "libvlc_internal.h"
  34
  35 #include <vlc_common.h>
  36
  37 /*
  38  * Event Handling
  39  */
  40
  41 /* Example usage
  42  *
  43  * struct libvlc_cool_object_t
  44  * {
  45  *        ...
  46  *        libvlc_event_manager_t * p_event_manager;
  47  *        ...
  48  * }
  49  *
  50  * libvlc_my_cool_object_new()
  51  * {
  52  *        ...
  53  *        p_self->p_event_manager = libvlc_event_manager_new( p_self )
  54  *        ...
  55  * }
  56  *
  57  * libvlc_my_cool_object_release()
  58  * {
  59  *         ...
  60  *         libvlc_event_manager_release( p_self->p_event_manager );
  61  *         ...
  62  * }
  63  *
  64  * libvlc_my_cool_object_do_something()
  65  * {
  66  *        ...
  67  *        libvlc_event_t event;
  68  *        event.type = libvlc_MyCoolObjectDidSomething;
  69  *        event.u.my_cool_object_did_something.what_it_did = kSomething;
  70  *        libvlc_event_send( p_self->p_event_manager, &event );
  71  * }
  72  * */
  73
  74 typedef struct libvlc_event_listener_t
  75 {
  76     libvlc_event_type_t event_type;
  77     void *              p_user_data;
  78     libvlc_callback_t   pf_callback;
  79 } libvlc_event_listener_t;
  80
  81 typedef struct libvlc_event_manager_t
  82 {
  83     void * p_obj;
  84     vlc_array_t listeners;
  85     vlc_mutex_t lock;
  86 } libvlc_event_sender_t;
  87
  88 /*
  89  * Internal libvlc functions
  90  */
  91
  92 /**************************************************************************
  93  *       libvlc_event_manager_new (internal) :
  94  *
  95  * Init an object's event manager.
  96  **************************************************************************/
  97 libvlc_event_manager_t *
  98 libvlc_event_manager_new( void * p_obj )
  99 {
 100     libvlc_event_manager_t * p_em;
 101
 102     p_em = malloc(sizeof( libvlc_event_manager_t ));
 103     if( !p_em )
 104     {
 105         libvlc_printerr( "Not enough memory" );
 106         return NULL;
 107     }
 108
 109     p_em->p_obj = p_obj;
 110     vlc_array_init(&p_em->listeners);
 111     vlc_mutex_init_recursive(&p_em->lock);
 112     return p_em;
 113 }
 114
 115 /**************************************************************************
 116  *       libvlc_event_manager_release (internal) :
 117  *
 118  * Release an object's event manager.
 119  **************************************************************************/
 120 void libvlc_event_manager_release( libvlc_event_manager_t * p_em )
 121 {
 122     vlc_mutex_destroy(&p_em->lock);
 123
 124     for (int i = 0; i < vlc_array_count(&p_em->listeners); i++)
 125         free(vlc_array_item_at_index(&p_em->listeners, i));
 126
 127     vlc_array_clear(&p_em->listeners);
 128     free( p_em );
 129 }
 130
 131 /**************************************************************************
 132  *       libvlc_event_send (internal) :
 133  *
 134  * Send a callback.
 135  **************************************************************************/
 136 void libvlc_event_send( libvlc_event_manager_t * p_em,
 137                         libvlc_event_t * p_event )
 138 {
 139     /* Fill event with the sending object now */
 140     p_event->p_obj = p_em->p_obj;
 141
 142     vlc_mutex_lock(&p_em->lock);
 143     for (int i = 0; i < vlc_array_count(&p_em->listeners); i++)
 144     {
 145         libvlc_event_listener_t *listener;
 146
 147         listener = vlc_array_item_at_index(&p_em->listeners, i);
 148         if (listener->event_type == p_event->type)
 149             listener->pf_callback(p_event, listener->p_user_data);
 150     }
 151     vlc_mutex_unlock(&p_em->lock);
 152 }
 153
 154 /*
 155  * Public libvlc functions
 156  */
 157
 158 #define DEF( a ) { libvlc_##a, #a, },
 159
 160 typedef struct
 161 {
 162     int type;
 163     const char name[40];
 164 } event_name_t;
 165
 166 static const event_name_t event_list[] = {
 167     DEF(MediaMetaChanged)
 168     DEF(MediaSubItemAdded)
 169     DEF(MediaDurationChanged)
 170     DEF(MediaParsedChanged)
 171     DEF(MediaFreed)
 172     DEF(MediaStateChanged)
 173     DEF(MediaSubItemTreeAdded)
 174
 175     DEF(MediaPlayerMediaChanged)
 176     DEF(MediaPlayerNothingSpecial)
 177     DEF(MediaPlayerOpening)
 178     DEF(MediaPlayerBuffering)
 179     DEF(MediaPlayerPlaying)
 180     DEF(MediaPlayerPaused)
 181     DEF(MediaPlayerStopped)
 182     DEF(MediaPlayerForward)
 183     DEF(MediaPlayerBackward)
 184     DEF(MediaPlayerEndReached)
 185     DEF(MediaPlayerEncounteredError)
 186     DEF(MediaPlayerTimeChanged)
 187     DEF(MediaPlayerPositionChanged)
 188     DEF(MediaPlayerSeekableChanged)
 189     DEF(MediaPlayerPausableChanged)
 190     DEF(MediaPlayerTitleChanged)
 191     DEF(MediaPlayerSnapshotTaken)
 192     DEF(MediaPlayerLengthChanged)
 193     DEF(MediaPlayerVout)
 194     DEF(MediaPlayerScrambledChanged)
 195     DEF(MediaPlayerESAdded)
 196     DEF(MediaPlayerESDeleted)
 197     DEF(MediaPlayerESSelected)
 198     DEF(MediaPlayerCorked)
 199     DEF(MediaPlayerUncorked)
 200     DEF(MediaPlayerMuted)
 201     DEF(MediaPlayerUnmuted)
 202     DEF(MediaPlayerAudioVolume)
 203     DEF(MediaPlayerAudioDevice)
 204
 205     DEF(MediaListItemAdded)
 206     DEF(MediaListWillAddItem)
 207     DEF(MediaListItemDeleted)
 208     DEF(MediaListWillDeleteItem)
 209
 210     DEF(MediaListViewItemAdded)
 211     DEF(MediaListViewWillAddItem)
 212     DEF(MediaListViewItemDeleted)
 213     DEF(MediaListViewWillDeleteItem)
 214
 215     DEF(MediaListPlayerPlayed)
 216     DEF(MediaListPlayerNextItemSet)
 217     DEF(MediaListPlayerStopped)
 218
 219     DEF(MediaDiscovererStarted)
 220     DEF(MediaDiscovererEnded)
 221
 222     DEF(VlmMediaAdded)
 223     DEF(VlmMediaRemoved)
 224     DEF(VlmMediaChanged)
 225     DEF(VlmMediaInstanceStarted)
 226     DEF(VlmMediaInstanceStopped)
 227     DEF(VlmMediaInstanceStatusInit)
 228     DEF(VlmMediaInstanceStatusOpening)
 229     DEF(VlmMediaInstanceStatusPlaying)
 230     DEF(VlmMediaInstanceStatusPause)
 231     DEF(VlmMediaInstanceStatusEnd)
 232     DEF(VlmMediaInstanceStatusError)
 233 };
 234 #undef DEF
 235
 236 static const char unknown_event_name[] = "Unknown Event";
 237
 238 static int evcmp( const void *a, const void *b )
 239 {
 240     return (*(const int *)a) - ((event_name_t *)b)->type;
 241 }
 242
 243 const char * libvlc_event_type_name( int event_type )
 244 {
 245     const event_name_t *p;
 246
 247     p = bsearch( &event_type, event_list,
 248                  sizeof(event_list)/sizeof(event_list[0]), sizeof(*p),
 249                  evcmp );
 250     return p ? p->name : unknown_event_name;
 251 }
 252
 253 /**************************************************************************
 254  *       libvlc_event_attach (public) :
 255  *
 256  * Add a callback for an event.
 257  **************************************************************************/
 258 int libvlc_event_attach(libvlc_event_manager_t *em, libvlc_event_type_t type,
 259                         libvlc_callback_t callback, void *opaque)
 260 {
 261     libvlc_event_listener_t *listener = malloc(sizeof (*listener));
 262     if (unlikely(listener == NULL))
 263         return ENOMEM;
 264
 265     listener->event_type = type;
 266     listener->p_user_data = opaque;
 267     listener->pf_callback = callback;
 268
 269     vlc_mutex_lock(&em->lock);
 270     vlc_array_append(&em->listeners, listener);
 271     vlc_mutex_unlock(&em->lock);
 272     return 0;
 273 }
 274
 275 /**************************************************************************
 276  *       libvlc_event_detach (public) :
 277  *
 278  * Remove a callback for an event.
 279  **************************************************************************/
 280 void libvlc_event_detach(libvlc_event_manager_t *em, libvlc_event_type_t type,
 281                          libvlc_callback_t callback, void *opaque)
 282 {
 283     vlc_mutex_lock(&em->lock);
 284     for (int i = 0; i < vlc_array_count(&em->listeners); i++)
 285     {
 286          libvlc_event_listener_t *listener;
 287
 288          listener = vlc_array_item_at_index(&em->listeners, i);
 289
 290          if (listener->event_type == type
 291           && listener->pf_callback == callback
 292           && listener->p_user_data == opaque)
 293          {   /* that's our listener */
 294              vlc_array_remove(&em->listeners, i);
 295              vlc_mutex_unlock(&em->lock);
 296              free(listener);
 297              return;
 298          }
 299     }
 300     abort();
 301 }