Use GnomeWallClock instead of periodic timeout

This class support changes in the timezone and notifications of clock skews
when using a recent version of Linux (using timerfds)
See https://bugzilla.gnome.org/show_bug.cgi?id=655129

Fixes https://bugs.launchpad.net/indicator-datetime/+bug/837440

2 files changed, 14 insertions, 65 deletions

diff --git a/configure.ac b/configure.ac
index 71fd0e9..7c7317f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -64,6 +64,7 @@ GEOCLUE_REQUIRED_VERSION=0.12.0
 ECAL_REQUIRED_VERSION=2.30
 EDS_REQUIRED_VERSION=2.30
 ICAL_REQUIRED_VERSION=0.44
+GNOME_DESKTOP_REQUIRED_VERSION=3.1.90
 CAIRO_REQUIRED_VERSION=1.10
 GDK_REQUIRED_VERSION=2.22
 GLIB_REQUIRED_VERSION=2.26
@@ -100,6 +101,7 @@ PKG_CHECK_MODULES(SERVICE, indicator3-0.4 >= $INDICATOR_REQUIRED_VERSION
                            libedataserverui-3.0 >= EDS_REQUIRED_VERSION
                            cairo >= CAIRO_REQUIRED_VERSION
                            gdk-3.0 >= GDK_REQUIRED_VERSION
+                           gnome-desktop-3.0 >= $GNOME_DESKTOP_REQUIRED_VERSION
                            gconf-2.0 >= GCONF_REQUIRED_VERSION)
 
 PKG_CHECK_MODULES(PREF, gio-2.0 >= $GIO_REQUIRED_VERSION
diff --git a/src/datetime-service.c b/src/datetime-service.c
index 80c0b57..8026398 100644
--- a/src/datetime-service.c
+++ b/src/datetime-service.c
@@ -38,6 +38,10 @@ with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <geoclue/geoclue-master.h>
 #include <geoclue/geoclue-master-client.h>
 
+#define GNOME_DESKTOP_USE_UNSTABLE_API
+#include <gdesktop-enums.h>
+#include <libgnome-desktop/gnome-wall-clock.h>
+
 #include <time.h>
 #include <libecal/e-cal.h>
 #include <libical/ical.h>
@@ -57,7 +61,6 @@ with this program.  If not, see <http://www.gnu.org/licenses/>.
 static void geo_create_client (GeoclueMaster * master, GeoclueMasterClient * client, gchar * path, GError * error, gpointer user_data);
 static gboolean update_appointment_menu_items (gpointer user_data);
 static gboolean update_timezone_menu_items(gpointer user_data);
-static void setup_timer (void);
 static void geo_client_invalid (GeoclueMasterClient * client, gpointer user_data);
 static void geo_address_change (GeoclueMasterClient * client, gchar * a, gchar * b, gchar * c, gchar * d, gpointer user_data);
 static gboolean get_greeter_mode (void);
@@ -1139,67 +1142,12 @@ build_menus (DbusmenuMenuitem * root)
 	return;
 }
 
-/* Run when the timezone file changes */
 static void
-timezone_changed (GFileMonitor * monitor, GFile * file, GFile * otherfile, GFileMonitorEvent event, gpointer user_data)
+on_clock_changed (GnomeWallClock *clock,
+                  GParamSpec     *pspec,
+                  gpointer        user_data)
 {
-	update_current_timezone();
-	datetime_interface_update(DATETIME_INTERFACE(user_data));
-	update_datetime(NULL);
-	setup_timer();
-	return;
-}
-
-/* Set up monitoring the timezone file */
-static void
-build_timezone (DatetimeInterface * dbus)
-{
-	GFile * timezonefile = g_file_new_for_path(TIMEZONE_FILE);
-	GFileMonitor * monitor = g_file_monitor_file(timezonefile, G_FILE_MONITOR_NONE, NULL, NULL);
-	if (monitor != NULL) {
-		g_signal_connect(G_OBJECT(monitor), "changed", G_CALLBACK(timezone_changed), dbus);
-		g_debug("Monitoring timezone file: '" TIMEZONE_FILE "'");
-	} else {
-		g_warning("Unable to monitor timezone file: '" TIMEZONE_FILE "'");
-	}
-	return;
-}
-
-/* Source ID for the timer */
-static guint timer = 0;
-
-/* Execute at a given time, update and setup a new
-   timer to go again.  */
-static gboolean
-timer_func (gpointer user_data)
-{
-	timer = 0;
-	/* Reset up each time to reduce error */
-	setup_timer();
-	update_datetime(NULL);
-	return FALSE;
-}
-
-/* Sets up the time to launch the timer to update the
-   date in the datetime entry */
-static void
-setup_timer (void)
-{
-	if (timer != 0) {
-		g_source_remove(timer);
-		timer = 0;
-	}
-
-	time_t t;
-	t = time(NULL);
-	struct tm * ltime = localtime(&t);
-
-	timer = g_timeout_add_seconds(((23 - ltime->tm_hour) * 60 * 60) +
-	                              ((59 - ltime->tm_min) * 60) +
-	                              ((60 - ltime->tm_sec)) + 60 /* one minute past */,
-	                              timer_func, NULL);
-
-	return;
+  update_datetime (NULL);
 }
 
 static void
@@ -1213,7 +1161,6 @@ session_active_change_cb (GDBusProxy * proxy, gchar * sender_name, gchar * signa
 		if (!idle) {
 			datetime_interface_update(DATETIME_INTERFACE(user_data));
 			update_datetime(NULL);
-			setup_timer();
 		}
 	}
 	return;
@@ -1437,6 +1384,8 @@ service_shutdown (IndicatorService * service, gpointer user_data)
 int
 main (int argc, char ** argv)
 {
+	GnomeWallClock *clock;
+
 	g_type_init();
 
 	/* Acknowledging the service init and setting up the interface */
@@ -1472,11 +1421,9 @@ main (int argc, char ** argv)
 	/* Setup dbus interface */
 	dbus = g_object_new(DATETIME_INTERFACE_TYPE, NULL);
 
-	/* Setup timezone watch */
-	build_timezone(dbus);
-
 	/* Setup the timer */
-	setup_timer();
+	clock = g_object_new (GNOME_TYPE_WALL_CLOCK, NULL);
+	g_signal_connect (priv->clock_tracker, "notify::clock", G_CALLBACK (on_clock_changed), NULL);
 
 	/* And watch for system resumes */
 	g_dbus_proxy_new_for_bus (G_BUS_TYPE_SYSTEM,