f1d51a8e2deaa9b475a79998ad910e51b19022ea
[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 *psz_path,
136                                             const char *const *ppsz_args )
137 {
138     pid_t pid;
139     switch( pid = fork() )
140     {
141         case 0:     /* we're the child */
142             /* We don't want output */
143             fclose( stdout );
144             fclose( stderr );
145             execv( psz_path, (char *const *)ppsz_args );
146             /* If the file we want to execute doesn't exist we exit() */
147             exit( -1 );
148             break;
149         case -1:    /* we're the error */
150             msg_Dbg( p_this, "Couldn't fork() while launching %s", psz_path );
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             waitpid( pid, NULL, 0 );
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 #ifdef HAVE_DBUS
169     p_intf->p_sys->p_connection = dbus_init( p_intf );
170 #endif
171
172     vlc_object_lock( p_intf );
173     for(;;)
174     {
175         vlc_object_t *p_vout;
176
177         /* Check screensaver every 30 seconds */
178         if( vlc_object_timedwait( p_intf, mdate() + 30000000 ) < 0 )
179             break;
180
181         p_vout = vlc_object_find( p_intf, VLC_OBJECT_VOUT, FIND_ANYWHERE );
182
183         /* If there is a video output, disable xscreensaver */
184         if( p_vout )
185         {
186             input_thread_t *p_input;
187             p_input = vlc_object_find( p_vout, VLC_OBJECT_INPUT, FIND_PARENT );
188             vlc_object_release( p_vout );
189             if( p_input )
190             {
191                 if( PLAYING_S == p_input->i_state )
192                 {
193                     /* http://www.jwz.org/xscreensaver/faq.html#dvd */
194                     const char *const ppsz_xsargs[] = { "/bin/sh", "-c",
195                             "xscreensaver-command -deactivate &", (char*)NULL };
196                     Execute( p_intf, "/bin/sh", ppsz_xsargs );
197
198                     /* If we have dbus support, let's communicate directly
199                        with gnome-screensave else, run
200                        gnome-screensaver-command */
201 #ifdef HAVE_DBUS
202                     poke_screensaver( p_intf, p_intf->p_sys->p_connection );
203 #else
204                     const char *const ppsz_gsargs[] = { "/bin/sh", "-c",
205                             "gnome-screensaver-command --poke &", (char*)NULL };
206                     Execute( p_intf, "/bin/sh", ppsz_gsargs );
207 #endif
208                     /* FIXME: add support for other screensavers */
209                 }
210                 vlc_object_release( p_input );
211             }
212         }
213     }
214     vlc_object_unlock( p_intf );
215 }
216
217 #ifdef HAVE_DBUS
218
219 static DBusConnection * dbus_init( intf_thread_t *p_intf )
220 {
221     DBusError dbus_error;
222
223     dbus_error_init (&dbus_error);
224     DBusConnection * p_connection = dbus_bus_get( DBUS_BUS_SESSION, &dbus_error );
225
226     if ( !p_connection )
227     {
228         msg_Warn( p_intf, "failed to connect to the D-BUS daemon: %s",
229                           dbus_error.message);
230         dbus_error_free( &dbus_error );
231         return NULL;
232     }
233
234     return p_connection;
235 }
236
237 static void poke_screensaver( intf_thread_t *p_intf,
238                               DBusConnection *p_connection )
239 {
240     if( screensaver_is_running( p_connection ) )
241     {
242 #   ifdef SCREENSAVER_DEBUG
243         msg_Dbg( p_intf, "found a running gnome-screensaver instance" );
244 #   endif
245         /* gnome-screensaver changed it's D-Bus interface, so we need both */
246         screensaver_send_message_void( p_intf, p_connection, "Poke" );
247         screensaver_send_message_void( p_intf, p_connection,
248                 "SimulateUserActivity" );
249     }
250 #   ifdef SCREENSAVER_DEBUG
251     else
252     {
253         msg_Dbg( p_intf, "found no running gnome-screensaver instance" );
254     }
255 #   endif
256 }
257
258 static void screensaver_send_message_void ( intf_thread_t *p_intf,
259                                        DBusConnection *p_connection,
260                                        const char *psz_name )
261 {
262     DBusMessage *p_message;
263
264     if( !p_connection || !psz_name ) return;
265
266     p_message = dbus_message_new_method_call( GS_SERVICE, GS_PATH,
267                                               GS_INTERFACE, psz_name );
268     if( p_message == NULL )
269     {
270         msg_Err( p_intf, "DBUS initialization failed: message initialization" );
271         return;
272     }
273
274     if( !dbus_connection_send( p_connection, p_message, NULL ) )
275     {
276         msg_Err( p_intf, "DBUS communication failed" );
277     }
278
279     dbus_connection_flush( p_connection );
280
281     dbus_message_unref( p_message );
282 }
283
284 static vlc_bool_t screensaver_is_running( DBusConnection *p_connection )
285 {
286     DBusError error;
287     vlc_bool_t b_return;
288
289     if( !p_connection ) return VLC_FALSE;
290
291     dbus_error_init( &error );
292     b_return = dbus_bus_name_has_owner( p_connection, GS_SERVICE, &error );
293     if( dbus_error_is_set( &error ) ) dbus_error_free (&error);
294
295     return b_return;
296 }
297
298 #endif
299