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[vlc.git] / modules / misc / screensaver.c
1 /*****************************************************************************
2  * screensaver.c : disable screen savers when VLC is playing
3  *****************************************************************************
4  * Copyright (C) 2006 the VideoLAN team
5  * $Id$
6  *
7  * Authors: Sam Hocevar <sam@zoy.org>
8  *          Benjamin Pracht <bigben AT videolan DOT org>
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 /*****************************************************************************
26  * Preamble
27  *****************************************************************************/
28
29 #include <vlc/vlc.h>
30 #include <vlc_input.h>
31 #include <vlc_interface.h>
32 #include <vlc_aout.h>
33 #include <vlc_vout.h>
34
35 #include <sys/types.h>
36 #include <sys/wait.h>
37 #include <unistd.h>
38
39 #ifdef HAVE_DBUS
40
41 #define DBUS_API_SUBJECT_TO_CHANGE
42 #include <dbus/dbus.h>
43
44 #define GS_SERVICE   "org.gnome.ScreenSaver"
45 #define GS_PATH      "/org/gnome/ScreenSaver"
46 #define GS_INTERFACE "org.gnome.ScreenSaver"
47
48 #endif
49
50 /* this is for dbus < 0.3 */
51 #ifndef HAVE_DBUS_1
52 #define dbus_bus_name_has_owner(connection, name, err) dbus_bus_service_exists(connection, name, err)
53 #endif
54
55 /*****************************************************************************
56  * Local prototypes
57  *****************************************************************************/
58 static int  Activate     ( vlc_object_t * );
59 static void  Deactivate   ( vlc_object_t * );
60
61 static void Run          ( intf_thread_t *p_intf );
62
63 #ifdef HAVE_DBUS
64
65 static DBusConnection * dbus_init( intf_thread_t *p_intf );
66 static void poke_screensaver( intf_thread_t *p_intf,
67                               DBusConnection *p_connection );
68 static void screensaver_send_message_void ( intf_thread_t *p_intf,
69                                        DBusConnection *p_connection,
70                                        const char *psz_name );
71 static vlc_bool_t screensaver_is_running( DBusConnection *p_connection );
72
73
74 struct intf_sys_t
75 {
76     DBusConnection *p_connection;
77 };
78
79 #endif
80
81 /*****************************************************************************
82  * Module descriptor
83  *****************************************************************************/
84 vlc_module_begin();
85     set_description( _("X Screensaver disabler") );
86     set_capability( "interface", 0 );
87     set_callbacks( Activate, Deactivate );
88 vlc_module_end();
89
90 /*****************************************************************************
91  * Activate: initialize and create stuff
92  *****************************************************************************/
93 static int Activate( vlc_object_t *p_this )
94 {
95     intf_thread_t *p_intf = (intf_thread_t*)p_this;
96
97     p_intf->pf_run = Run;
98
99 #ifdef HAVE_DBUS
100     p_intf->p_sys = (intf_sys_t *)malloc( sizeof( intf_sys_t ) );
101     if( !p_intf->p_sys ) return VLC_ENOMEM;
102 #endif
103
104     return VLC_SUCCESS;
105 }
106
107 /*****************************************************************************
108  * Deactivate: uninitialize and cleanup
109  *****************************************************************************/
110 static void Deactivate( vlc_object_t *p_this )
111 {
112 #ifdef HAVE_DBUS
113     intf_thread_t *p_intf = (intf_thread_t*)p_this;
114
115     if( p_intf->p_sys->p_connection )
116     {
117 #  ifdef HAVE_DBUS_2
118         dbus_connection_unref( p_intf->p_sys->p_connection );
119 #  else
120         dbus_connection_disconnect( p_intf->p_sys->p_connection );
121 #  endif
122     }
123
124     if( p_intf->p_sys )
125     {
126         free( p_intf->p_sys );
127         p_intf->p_sys = NULL;
128     }
129 #endif
130 }
131
132 /*****************************************************************************
133  * Execute: Spawns a process using execv()
134  *****************************************************************************/
135 static void Execute( intf_thread_t *p_this, const char *const *ppsz_args )
136 {
137     pid_t pid;
138     switch( pid = fork() )
139     {
140         case 0:     /* we're the child */
141             /* We don't want output */
142             freopen( "/dev/null", "w", stdout );
143             freopen( "/dev/null", "w", stderr );
144             execv( ppsz_args[0] , (char *const *)ppsz_args );
145             /* If the file we want to execute doesn't exist we exit() */
146             exit( 1 );
147             break;
148         case -1:    /* we're the error */
149             msg_Dbg( p_this, "Couldn't fork() while launching %s",
150                      ppsz_args[0] );
151             break;
152         default:    /* we're the parent */
153             /* Wait for the child to exit.
154              * We will not deadlock because we ran "/bin/sh &" */
155             while( waitpid( pid, NULL, 0 ) != pid);
156             break;
157     }
158 }
159
160 /*****************************************************************************
161  * Run: main thread
162  *****************************************************************************
163  * This part of the module is in a separate thread so that we do not have
164  * too much system() overhead.
165  *****************************************************************************/
166 static void Run( intf_thread_t *p_intf )
167 {
168     vlc_object_lock( p_intf );
169
170 #ifdef HAVE_DBUS
171     p_intf->p_sys->p_connection = dbus_init( p_intf );
172 #endif
173
174     while( vlc_object_alive( p_intf ) )
175     {
176         vlc_object_t *p_vout;
177
178         /* Check screensaver every 30 seconds */
179         if( vlc_object_timedwait( p_intf, mdate() + 30000000 ) < 0 )
180             continue;
181
182         p_vout = vlc_object_find( p_intf, VLC_OBJECT_VOUT, FIND_ANYWHERE );
183
184         /* If there is a video output, disable xscreensaver */
185         if( p_vout )
186         {
187             input_thread_t *p_input;
188             p_input = vlc_object_find( p_vout, VLC_OBJECT_INPUT, FIND_PARENT );
189             vlc_object_release( p_vout );
190             if( p_input )
191             {
192                 if( PLAYING_S == p_input->i_state )
193                 {
194                     /* http://www.jwz.org/xscreensaver/faq.html#dvd */
195                     const char *const ppsz_xsargs[] = { "/bin/sh", "-c",
196                             "xscreensaver-command -deactivate &", (char*)NULL };
197                     Execute( p_intf, ppsz_xsargs );
198
199                     /* If we have dbus support, let's communicate directly
200                        with gnome-screensave else, run
201                        gnome-screensaver-command */
202 #ifdef HAVE_DBUS
203                     poke_screensaver( p_intf, p_intf->p_sys->p_connection );
204 #else
205                     const char *const ppsz_gsargs[] = { "/bin/sh", "-c",
206                             "gnome-screensaver-command --poke &", (char*)NULL };
207                     Execute( p_intf, ppsz_gsargs );
208 #endif
209                     /* FIXME: add support for other screensavers */
210                 }
211                 vlc_object_release( p_input );
212             }
213         }
214     }
215     vlc_object_unlock( p_intf );
216 }
217
218 #ifdef HAVE_DBUS
219
220 static DBusConnection * dbus_init( intf_thread_t *p_intf )
221 {
222     DBusError dbus_error;
223
224     dbus_error_init (&dbus_error);
225     DBusConnection * p_connection = dbus_bus_get( DBUS_BUS_SESSION, &dbus_error );
226
227     if ( !p_connection )
228     {
229         msg_Warn( p_intf, "failed to connect to the D-BUS daemon: %s",
230                           dbus_error.message);
231         dbus_error_free( &dbus_error );
232         return NULL;
233     }
234
235     return p_connection;
236 }
237
238 static void poke_screensaver( intf_thread_t *p_intf,
239                               DBusConnection *p_connection )
240 {
241     if( screensaver_is_running( p_connection ) )
242     {
243 #   ifdef SCREENSAVER_DEBUG
244         msg_Dbg( p_intf, "found a running gnome-screensaver instance" );
245 #   endif
246         /* gnome-screensaver changed it's D-Bus interface, so we need both */
247         screensaver_send_message_void( p_intf, p_connection, "Poke" );
248         screensaver_send_message_void( p_intf, p_connection,
249                 "SimulateUserActivity" );
250     }
251 #   ifdef SCREENSAVER_DEBUG
252     else
253     {
254         msg_Dbg( p_intf, "found no running gnome-screensaver instance" );
255     }
256 #   endif
257 }
258
259 static void screensaver_send_message_void ( intf_thread_t *p_intf,
260                                        DBusConnection *p_connection,
261                                        const char *psz_name )
262 {
263     DBusMessage *p_message;
264
265     if( !p_connection || !psz_name ) return;
266
267     p_message = dbus_message_new_method_call( GS_SERVICE, GS_PATH,
268                                               GS_INTERFACE, psz_name );
269     if( p_message == NULL )
270     {
271         msg_Err( p_intf, "DBUS initialization failed: message initialization" );
272         return;
273     }
274
275     if( !dbus_connection_send( p_connection, p_message, NULL ) )
276     {
277         msg_Err( p_intf, "DBUS communication failed" );
278     }
279
280     dbus_connection_flush( p_connection );
281
282     dbus_message_unref( p_message );
283 }
284
285 static vlc_bool_t screensaver_is_running( DBusConnection *p_connection )
286 {
287     DBusError error;
288     vlc_bool_t b_return;
289
290     if( !p_connection ) return VLC_FALSE;
291
292     dbus_error_init( &error );
293     b_return = dbus_bus_name_has_owner( p_connection, GS_SERVICE, &error );
294     if( dbus_error_is_set( &error ) ) dbus_error_free (&error);
295
296     return b_return;
297 }
298
299 #endif
300