modules/misc/inhibit.c

   1 /*****************************************************************************
   2  * inhibit.c : prevents the computer from suspending when VLC is playing
   3  *****************************************************************************
   4  * Copyright © 2007 Rafaël Carré
   5  * $Id$
   6  *
   7  * Author: Rafaël Carré <funman@videolanorg>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 /*
  25  * Based on freedesktop Power Management Specification version 0.2
  26  * http://people.freedesktop.org/~hughsient/temp/power-management-spec-0.2.html
  27  */
  28
  29 /*****************************************************************************
  30  * Preamble
  31  *****************************************************************************/
  32
  33 #ifdef HAVE_CONFIG_H
  34 # include "config.h"
  35 #endif
  36
  37 #include <vlc_common.h>
  38 #include <vlc_plugin.h>
  39 #include <vlc_input.h>
  40 #include <vlc_interface.h>
  41 #include <vlc_playlist.h>
  42
  43 #include <dbus/dbus.h>
  44
  45 #define PM_SERVICE   "org.freedesktop.PowerManagement"
  46 #define PM_PATH      "/org/freedesktop/PowerManagement/Inhibit"
  47 #define PM_INTERFACE "org.freedesktop.PowerManagement.Inhibit"
  48
  49 /*****************************************************************************
  50  * Local prototypes
  51  *****************************************************************************/
  52 static int  Activate     ( vlc_object_t * );
  53 static void Deactivate   ( vlc_object_t * );
  54
  55 static int Inhibit( intf_thread_t *p_intf );
  56 static int UnInhibit( intf_thread_t *p_intf );
  57
  58 static int InputChange( vlc_object_t *, const char *,
  59                         vlc_value_t, vlc_value_t, void * );
  60 static int StateChange( vlc_object_t *, const char *,
  61                         vlc_value_t, vlc_value_t, void * );
  62
  63 struct intf_sys_t
  64 {
  65     playlist_t      *p_playlist;
  66     vlc_object_t    *p_input;
  67     DBusConnection  *p_conn;
  68     dbus_uint32_t   i_cookie;
  69 };
  70
  71 /*****************************************************************************
  72  * Module descriptor
  73  *****************************************************************************/
  74 vlc_module_begin ()
  75     set_description( N_("Power Management Inhibitor") )
  76     set_capability( "interface", 0 )
  77     set_callbacks( Activate, Deactivate )
  78 vlc_module_end ()
  79
  80 /*****************************************************************************
  81  * Activate: initialize and create stuff
  82  *****************************************************************************/
  83 static int Activate( vlc_object_t *p_this )
  84 {
  85     intf_thread_t *p_intf = (intf_thread_t*)p_this;
  86     intf_sys_t *p_sys;
  87     DBusError     error;
  88
  89     p_sys = p_intf->p_sys = (intf_sys_t *) calloc( 1, sizeof( intf_sys_t ) );
  90     if( !p_sys )
  91         return VLC_ENOMEM;
  92
  93     p_sys->i_cookie = 0;
  94     p_sys->p_input = NULL;
  95
  96     dbus_error_init( &error );
  97     p_sys->p_conn = dbus_bus_get( DBUS_BUS_SESSION, &error );
  98     if( !p_sys->p_conn )
  99     {
 100         msg_Err( p_this, "Failed to connect to the D-Bus session daemon: %s",
 101                 error.message );
 102         dbus_error_free( &error );
 103         free( p_sys );
 104         return VLC_EGENERIC;
 105     }
 106
 107     p_sys->p_playlist = pl_Get( p_intf );
 108     var_AddCallback( p_sys->p_playlist, "item-current", InputChange, p_intf );
 109     return VLC_SUCCESS;
 110 }
 111
 112 /*****************************************************************************
 113  * Deactivate: uninitialize and cleanup
 114  *****************************************************************************/
 115 static void Deactivate( vlc_object_t *p_this )
 116 {
 117     intf_thread_t *p_intf = (intf_thread_t*)p_this;
 118     intf_sys_t *p_sys = p_intf->p_sys;
 119
 120     var_DelCallback( p_sys->p_playlist, "item-current", InputChange, p_intf );
 121
 122     if( p_sys->p_input ) /* Do delete "state" after "item-changed"! */
 123     {
 124         var_DelCallback( p_sys->p_input, "state", StateChange, p_intf );
 125         vlc_object_release( p_sys->p_input );
 126     }
 127
 128     if( p_sys->i_cookie )
 129         UnInhibit( p_intf );
 130     dbus_connection_unref( p_sys->p_conn );
 131
 132     free( p_sys );
 133 }
 134
 135 /*****************************************************************************
 136  * Inhibit: Notify the power management daemon that it shouldn't suspend
 137  * the computer because of inactivity
 138  *
 139  * returns false if Out of memory, else true
 140  *****************************************************************************/
 141 static int Inhibit( intf_thread_t *p_intf )
 142 {
 143     DBusConnection *p_conn;
 144     DBusMessage *p_msg;
 145     DBusMessageIter args;
 146     DBusMessage *p_reply;
 147     dbus_uint32_t i_cookie;
 148
 149     p_conn = p_intf->p_sys->p_conn;
 150
 151     p_msg = dbus_message_new_method_call( PM_SERVICE, PM_PATH, PM_INTERFACE,
 152                                           "Inhibit" );
 153     if( !p_msg )
 154         return false;
 155
 156     dbus_message_iter_init_append( p_msg, &args );
 157
 158     char *psz_app = strdup( PACKAGE );
 159     if( !psz_app ||
 160         !dbus_message_iter_append_basic( &args, DBUS_TYPE_STRING, &psz_app ) )
 161     {
 162         free( psz_app );
 163         dbus_message_unref( p_msg );
 164         return false;
 165     }
 166     free( psz_app );
 167
 168     char *psz_inhibit_reason = strdup( _("Playing some media.") );
 169     if( !psz_inhibit_reason )
 170     {
 171         dbus_message_unref( p_msg );
 172         return false;
 173     }
 174     if( !dbus_message_iter_append_basic( &args, DBUS_TYPE_STRING,
 175                                          &psz_inhibit_reason ) )
 176     {
 177         free( psz_inhibit_reason );
 178         dbus_message_unref( p_msg );
 179         return false;
 180     }
 181     free( psz_inhibit_reason );
 182
 183     p_reply = dbus_connection_send_with_reply_and_block( p_conn, p_msg,
 184         50, NULL ); /* blocks 50ms maximum */
 185     dbus_message_unref( p_msg );
 186     if( p_reply == NULL )
 187     {   /* g-p-m is not active, or too slow. Better luck next time? */
 188         return true;
 189     }
 190
 191     /* extract the cookie from the reply */
 192     if( dbus_message_get_args( p_reply, NULL,
 193             DBUS_TYPE_UINT32, &i_cookie,
 194             DBUS_TYPE_INVALID ) == FALSE )
 195     {
 196         return false;
 197     }
 198
 199     /* Save the cookie */
 200     p_intf->p_sys->i_cookie = i_cookie;
 201     return true;
 202 }
 203
 204 /*****************************************************************************
 205  * UnInhibit: Notify the power management daemon that we aren't active anymore
 206  *
 207  * returns false if Out of memory, else true
 208  *****************************************************************************/
 209 static int UnInhibit( intf_thread_t *p_intf )
 210 {
 211     DBusConnection *p_conn;
 212     DBusMessage *p_msg;
 213     DBusMessageIter args;
 214     dbus_uint32_t i_cookie;
 215
 216     p_conn = p_intf->p_sys->p_conn;
 217
 218     p_msg = dbus_message_new_method_call( PM_SERVICE, PM_PATH, PM_INTERFACE,
 219                                           "UnInhibit" );
 220     if( !p_msg )
 221         return false;
 222
 223     dbus_message_iter_init_append( p_msg, &args );
 224
 225     i_cookie = p_intf->p_sys->i_cookie;
 226     if( !dbus_message_iter_append_basic( &args, DBUS_TYPE_UINT32, &i_cookie ) )
 227     {
 228         dbus_message_unref( p_msg );
 229         return false;
 230     }
 231
 232     if( !dbus_connection_send( p_conn, p_msg, NULL ) )
 233         return false;
 234     dbus_connection_flush( p_conn );
 235
 236     dbus_message_unref( p_msg );
 237
 238     p_intf->p_sys->i_cookie = 0;
 239     return true;
 240 }
 241
 242
 243 static int StateChange( vlc_object_t *p_input, const char *var,
 244                         vlc_value_t prev, vlc_value_t value, void *data )
 245 {
 246     intf_thread_t *p_intf = data;
 247     const int old = prev.i_int, cur = value.i_int;
 248
 249     if( ( old == PLAYING_S ) == ( cur == PLAYING_S ) )
 250         return VLC_SUCCESS; /* No interesting change */
 251
 252     if( ( p_intf->p_sys->i_cookie != 0 ) == ( cur == PLAYING_S ) )
 253         return VLC_SUCCESS; /* Already in correct state */
 254
 255     if( cur == PLAYING_S )
 256         Inhibit( p_intf );
 257     else
 258         UnInhibit( p_intf );
 259
 260     (void)p_input; (void)var; (void)prev;
 261     return VLC_SUCCESS;
 262 }
 263
 264 static int InputChange( vlc_object_t *p_playlist, const char *var,
 265                         vlc_value_t prev, vlc_value_t value, void *data )
 266 {
 267     intf_thread_t *p_intf = data;
 268     intf_sys_t *p_sys = p_intf->p_sys;
 269
 270     if( p_sys->p_input )
 271     {
 272         var_DelCallback( p_sys->p_input, "state", StateChange, p_intf );
 273         vlc_object_release( p_sys->p_input );
 274     }
 275     p_sys->p_input = VLC_OBJECT(playlist_CurrentInput( p_sys->p_playlist ));
 276     if( p_sys->p_input )
 277         var_AddCallback( p_sys->p_input, "state", StateChange, p_intf );
 278
 279     (void)var; (void)prev; (void)value; (void)p_playlist;
 280     return VLC_SUCCESS;
 281 }