research.m1stereo.tv/gitweb/ - melted/blob - src/framework/mlt_events.c

   1 /*
   2  * mlt_events.h -- event handling
   3  * Copyright (C) 2004-2005 Ushodaya Enterprises Limited
   4  * Author: Charles Yates <charles.yates@pandora.be>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software Foundation,
  18  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  19  */
  20
  21 #include <stdlib.h>
  22 #include <stdarg.h>
  23 #include <string.h>
  24
  25 #include "mlt_properties.h"
  26 #include "mlt_events.h"
  27
  28 /** Memory leak checks.
  29 */
  30
  31 //#define _MLT_EVENT_CHECKS_
  32
  33 #ifdef _MLT_EVENT_CHECKS_
  34 static int events_created = 0;
  35 static int events_destroyed = 0;
  36 #endif
  37
  38 struct mlt_events_struct
  39 {
  40         mlt_properties owner;
  41         mlt_properties list;
  42 };
  43
  44 typedef struct mlt_events_struct *mlt_events;
  45
  46 struct mlt_event_struct
  47 {
  48         mlt_events owner;
  49         int ref_count;
  50         int block_count;
  51         mlt_listener listener;
  52         void *service;
  53 };
  54
  55 /** Increment the reference count on this event.
  56 */
  57
  58 void mlt_event_inc_ref( mlt_event this )
  59 {
  60         if ( this != NULL && this->owner != NULL )
  61                 this->ref_count ++;
  62 }
  63
  64 /** Increment the block count on this event.
  65 */
  66
  67 void mlt_event_block( mlt_event this )
  68 {
  69         if ( this != NULL && this->owner != NULL )
  70                 this->block_count ++;
  71 }
  72
  73 /** Decrement the block count on this event.
  74 */
  75
  76 void mlt_event_unblock( mlt_event this )
  77 {
  78         if ( this != NULL && this->owner != NULL )
  79                 this->block_count --;
  80 }
  81
  82 /** Close this event.
  83 */
  84
  85 void mlt_event_close( mlt_event this )
  86 {
  87         if ( this != NULL && this->owner != NULL )
  88         {
  89                 if ( -- this->ref_count == 1 )
  90                         this->owner = NULL;
  91                 if ( this->ref_count <= 0 )
  92                 {
  93 #ifdef _MLT_EVENT_CHECKS_
  94                         events_destroyed ++;
  95                         fprintf( stderr, "Events created %d, destroyed %d\n", events_created, events_destroyed );
  96 #endif
  97                         free( this );
  98                 }
  99         }
 100 }
 101
 102 /** Forward declaration to private functions.
 103 */
 104
 105 static mlt_events mlt_events_fetch( mlt_properties );
 106 static void mlt_events_store( mlt_properties, mlt_events );
 107 static void mlt_events_close( mlt_events );
 108
 109 /** Initialise the events structure.
 110 */
 111
 112 void mlt_events_init( mlt_properties this )
 113 {
 114         mlt_events events = mlt_events_fetch( this );
 115         if ( events == NULL )
 116         {
 117                 events = malloc( sizeof( struct mlt_events_struct ) );
 118                 events->list = mlt_properties_new( );
 119                 mlt_events_store( this, events );
 120         }
 121 }
 122
 123 /** Register an event and transmitter.
 124 */
 125
 126 int mlt_events_register( mlt_properties this, char *id, mlt_transmitter transmitter )
 127 {
 128         int error = 1;
 129         mlt_events events = mlt_events_fetch( this );
 130         if ( events != NULL )
 131         {
 132                 mlt_properties list = events->list;
 133                 char temp[ 128 ];
 134                 error = mlt_properties_set_data( list, id, transmitter, 0, NULL, NULL );
 135                 sprintf( temp, "list:%s", id );
 136                 if ( mlt_properties_get_data( list, temp, NULL ) == NULL )
 137                         mlt_properties_set_data( list, temp, mlt_properties_new( ), 0, ( mlt_destructor )mlt_properties_close, NULL );
 138         }
 139         return error;
 140 }
 141
 142 /** Fire an event.
 143 */
 144
 145 void mlt_events_fire( mlt_properties this, char *id, ... )
 146 {
 147         mlt_events events = mlt_events_fetch( this );
 148         if ( events != NULL )
 149         {
 150                 int i = 0;
 151                 va_list alist;
 152                 void *args[ 10 ];
 153                 mlt_properties list = events->list;
 154                 mlt_properties listeners = NULL;
 155                 char temp[ 128 ];
 156                 mlt_transmitter transmitter = mlt_properties_get_data( list, id, NULL );
 157                 sprintf( temp, "list:%s", id );
 158                 listeners = mlt_properties_get_data( list, temp, NULL );
 159
 160                 va_start( alist, id );
 161                 do
 162                         args[ i ] = va_arg( alist, void * );
 163                 while( args[ i ++ ] != NULL );
 164                 va_end( alist );
 165
 166                 if ( listeners != NULL )
 167                 {
 168                         for ( i = 0; i < mlt_properties_count( listeners ); i ++ )
 169                         {
 170                                 mlt_event event = mlt_properties_get_data_at( listeners, i, NULL );
 171                                 if ( event != NULL && event->owner != NULL && event->block_count == 0 )
 172                                 {
 173                                         if ( transmitter != NULL )
 174                                                 transmitter( event->listener, event->owner, event->service, args );
 175                                         else
 176                                                 event->listener( event->owner, event->service );
 177                                 }
 178                         }
 179                 }
 180         }
 181 }
 182
 183 /** Register a listener.
 184 */
 185
 186 mlt_event mlt_events_listen( mlt_properties this, void *service, char *id, mlt_listener listener )
 187 {
 188         mlt_event event = NULL;
 189         mlt_events events = mlt_events_fetch( this );
 190         if ( events != NULL )
 191         {
 192                 mlt_properties list = events->list;
 193                 mlt_properties listeners = NULL;
 194                 char temp[ 128 ];
 195                 sprintf( temp, "list:%s", id );
 196                 listeners = mlt_properties_get_data( list, temp, NULL );
 197                 if ( listeners != NULL )
 198                 {
 199                         int first_null = -1;
 200                         int i = 0;
 201                         for ( i = 0; event == NULL && i < mlt_properties_count( listeners ); i ++ )
 202                         {
 203                                 mlt_event entry = mlt_properties_get_data_at( listeners, i, NULL );
 204                                 if ( entry != NULL && entry->owner != NULL )
 205                                 {
 206                                         if ( entry->service == service && entry->listener == listener )
 207                                                 event = entry;
 208                                 }
 209                                 else if ( ( entry == NULL || entry->owner == NULL ) && first_null == -1 )
 210                                 {
 211                                         first_null = i;
 212                                 }
 213                         }
 214
 215                         if ( event == NULL )
 216                         {
 217                                 event = malloc( sizeof( struct mlt_event_struct ) );
 218                                 if ( event != NULL )
 219                                 {
 220 #ifdef _MLT_EVENT_CHECKS_
 221                                         events_created ++;
 222 #endif
 223                                         sprintf( temp, "%d", first_null == -1 ? mlt_properties_count( listeners ) : first_null );
 224                                         event->owner = events;
 225                                         event->ref_count = 0;
 226                                         event->block_count = 0;
 227                                         event->listener = listener;
 228                                         event->service = service;
 229                                         mlt_properties_set_data( listeners, temp, event, 0, ( mlt_destructor )mlt_event_close, NULL );
 230                                 }
 231                         }
 232
 233                         if ( event != NULL )
 234                                 mlt_event_inc_ref( event );
 235                 }
 236         }
 237         return event;
 238 }
 239
 240 /** Block all events for a given service.
 241 */
 242
 243 void mlt_events_block( mlt_properties this, void *service )
 244 {
 245         mlt_events events = mlt_events_fetch( this );
 246         if ( events != NULL )
 247         {
 248                 int i = 0, j = 0;
 249                 mlt_properties list = events->list;
 250                 for ( j = 0; j < mlt_properties_count( list ); j ++ )
 251                 {
 252                         char *temp = mlt_properties_get_name( list, j );
 253                         if ( !strncmp( temp, "list:", 5 ) )
 254                         {
 255                                 mlt_properties listeners = mlt_properties_get_data( list, temp, NULL );
 256                                 for ( i = 0; i < mlt_properties_count( listeners ); i ++ )
 257                                 {
 258                                         mlt_event entry = mlt_properties_get_data_at( listeners, i, NULL );
 259                                         if ( entry != NULL && entry->service == service )
 260                                                 mlt_event_block( entry );
 261                                 }
 262                         }
 263                 }
 264         }
 265 }
 266
 267 /** Unblock all events for a given service.
 268 */
 269
 270 void mlt_events_unblock( mlt_properties this, void *service )
 271 {
 272         mlt_events events = mlt_events_fetch( this );
 273         if ( events != NULL )
 274         {
 275                 int i = 0, j = 0;
 276                 mlt_properties list = events->list;
 277                 for ( j = 0; j < mlt_properties_count( list ); j ++ )
 278                 {
 279                         char *temp = mlt_properties_get_name( list, j );
 280                         if ( !strncmp( temp, "list:", 5 ) )
 281                         {
 282                                 mlt_properties listeners = mlt_properties_get_data( list, temp, NULL );
 283                                 for ( i = 0; i < mlt_properties_count( listeners ); i ++ )
 284                                 {
 285                                         mlt_event entry = mlt_properties_get_data_at( listeners, i, NULL );
 286                                         if ( entry != NULL && entry->service == service )
 287                                                 mlt_event_unblock( entry );
 288                                 }
 289                         }
 290                 }
 291         }
 292 }
 293
 294 /** Disconnect all events for a given service.
 295 */
 296
 297 void mlt_events_disconnect( mlt_properties this, void *service )
 298 {
 299         mlt_events events = mlt_events_fetch( this );
 300         if ( events != NULL )
 301         {
 302                 int i = 0, j = 0;
 303                 mlt_properties list = events->list;
 304                 for ( j = 0; j < mlt_properties_count( list ); j ++ )
 305                 {
 306                         char *temp = mlt_properties_get_name( list, j );
 307                         if ( !strncmp( temp, "list:", 5 ) )
 308                         {
 309                                 mlt_properties listeners = mlt_properties_get_data( list, temp, NULL );
 310                                 for ( i = 0; i < mlt_properties_count( listeners ); i ++ )
 311                                 {
 312                                         mlt_event entry = mlt_properties_get_data_at( listeners, i, NULL );
 313                                         char *name = mlt_properties_get_name( listeners, i );
 314                                         if ( entry != NULL && entry->service == service )
 315                                                 mlt_properties_set_data( listeners, name, NULL, 0, NULL, NULL );
 316                                 }
 317                         }
 318                 }
 319         }
 320 }
 321
 322 /** Fetch the events object.
 323 */
 324
 325 static mlt_events mlt_events_fetch( mlt_properties this )
 326 {
 327         mlt_events events = NULL;
 328         if ( this != NULL )
 329                 events = mlt_properties_get_data( this, "_events", NULL );
 330         return events;
 331 }
 332
 333 /** Store the events object.
 334 */
 335
 336 static void mlt_events_store( mlt_properties this, mlt_events events )
 337 {
 338         if ( this != NULL && events != NULL )
 339                 mlt_properties_set_data( this, "_events", events, 0, ( mlt_destructor )mlt_events_close, NULL );
 340 }
 341
 342 /** Close the events object.
 343 */
 344
 345 static void mlt_events_close( mlt_events events )
 346 {
 347         if ( events != NULL )
 348         {
 349                 mlt_properties_close( events->list );
 350                 free( events );
 351         }
 352 }
 353