Fix #80: Add Geoclue2 location provider

This simply runs a GLib main loop when the location is requested
and tries to get the location from GeoClue2. We need to run a
main loop since the location is not immediately available, instead
it becomes available through a signal.

1 files changed, 281 insertions, 0 deletions

diff --git a/src/location-geoclue2.c b/src/location-geoclue2.c
new file mode 100644
index 0000000..4c4150e
--- /dev/null
+++ b/src/location-geoclue2.c
@@ -0,0 +1,281 @@
+/* location-geoclue2.c -- GeoClue2 location provider source
+   This file is part of Redshift.
+
+   Redshift is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Redshift is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Redshift.  If not, see <http://www.gnu.org/licenses/>.
+
+   Copyright (c) 2014  Jon Lund Steffensen <jonlst@gmail.com>
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <glib.h>
+#include <glib/gprintf.h>
+#include <gio/gio.h>
+
+#include "location-geoclue2.h"
+
+#ifdef ENABLE_NLS
+# include <libintl.h>
+# define _(s) gettext(s)
+#else
+# define _(s) s
+#endif
+
+
+typedef struct {
+	GMainLoop *loop;
+
+	int available;
+	float latitude;
+	float longitude;
+} get_location_data_t;
+
+
+int
+location_geoclue2_init(void *state)
+{
+#if !GLIB_CHECK_VERSION(2, 35, 0)
+	g_type_init();
+#endif
+	return 0;
+}
+
+int
+location_geoclue2_start(void *state)
+{
+	return 0;
+}
+
+void
+location_geoclue2_free(void *state)
+{
+}
+
+void
+location_geoclue2_print_help(FILE *f)
+{
+	fputs(_("Use the location as discovered by a GeoClue2 provider.\n"), f);
+	fputs("\n", f);
+
+	fputs(_("NOTE: currently redshift doesn't recheck GeoClue2 once started,\n"
+		"which means it has to be restarted to take notice after travel.\n"),
+	      f);
+	fputs("\n", f);
+}
+
+int
+location_geoclue2_set_option(void *state,
+			    const char *key, const char *value)
+{
+	fprintf(stderr, _("Unknown method parameter: `%s'.\n"), key);
+	return -1;
+}
+
+/* Handle position change callbacks */
+static void
+geoclue_client_signal_cb(GDBusProxy *client, gchar *sender_name,
+			 gchar *signal_name, GVariant *parameters,
+			 gpointer *user_data)
+{
+	get_location_data_t *data = (get_location_data_t *)user_data;
+
+	/* Only handle LocationUpdated signals */
+	if (g_strcmp0(signal_name, "LocationUpdated") != 0) {
+		return;
+	}
+
+	/* Obtain location path */
+	const gchar *location_path;
+	g_variant_get_child(parameters, 1, "&o", &location_path);
+
+	/* Obtain location */
+	GError *error = NULL;
+	GDBusProxy *location =
+		g_dbus_proxy_new_for_bus_sync(G_BUS_TYPE_SYSTEM,
+					      G_DBUS_PROXY_FLAGS_NONE,
+					      NULL,
+					      "org.freedesktop.GeoClue2",
+					      location_path,
+					      "org.freedesktop.GeoClue2.Location",
+					      NULL, &error);
+	if (location == NULL) {
+		g_printerr(_("Unable to obtain location: %s.\n"),
+			   error->message);
+		g_error_free(error);
+		return;
+	}
+
+	/* Read location properties */
+	GVariant *lat_v = g_dbus_proxy_get_cached_property(location,
+							   "Latitude");
+	data->latitude = g_variant_get_double(lat_v);
+
+	GVariant *lon_v = g_dbus_proxy_get_cached_property(location,
+							   "Longitude");
+	data->longitude = g_variant_get_double(lon_v);
+
+	data->available = 1;
+
+	/* Return from main loop */
+	g_main_loop_quit(data->loop);
+}
+
+/* Callback when GeoClue name appears on the bus */
+static void
+on_name_appeared(GDBusConnection *conn, const gchar *name,
+		 const gchar *name_owner, gpointer user_data)
+{
+	get_location_data_t *data = (get_location_data_t *)user_data;
+
+	/* Obtain GeoClue Manager */
+	GError *error = NULL;
+	GDBusProxy *geoclue_manager =
+		g_dbus_proxy_new_for_bus_sync(G_BUS_TYPE_SYSTEM,
+					      G_DBUS_PROXY_FLAGS_NONE,
+					      NULL,
+					      "org.freedesktop.GeoClue2",
+					      "/org/freedesktop/GeoClue2/Manager",
+					      "org.freedesktop.GeoClue2.Manager",
+					      NULL, &error);
+	if (geoclue_manager == NULL) {
+		g_printerr(_("Unable to obtain GeoClue Manager: %s.\n"),
+			   error->message);
+		g_error_free(error);
+		return;
+	}
+
+	/* Obtain GeoClue Client path */
+	error = NULL;
+	GVariant *client_path_v =
+		g_dbus_proxy_call_sync(geoclue_manager,
+				       "GetClient",
+				       NULL,
+				       G_DBUS_CALL_FLAGS_NONE,
+				       -1, NULL, &error);
+	if (client_path_v == NULL) {
+		g_printerr(_("Unable to obtain GeoClue client path: %s.\n"),
+			   error->message);
+		g_error_free(error);
+		g_object_unref(geoclue_manager);
+		return;
+	}
+
+	const gchar *client_path;
+	g_variant_get(client_path_v, "(&o)", &client_path);
+
+	/* Obtain GeoClue client */
+	error = NULL;
+	GDBusProxy *geoclue_client =
+		g_dbus_proxy_new_for_bus_sync(G_BUS_TYPE_SYSTEM,
+					      G_DBUS_PROXY_FLAGS_NONE,
+					      NULL,
+					      "org.freedesktop.GeoClue2",
+					      client_path,
+					      "org.freedesktop.GeoClue2.Client",
+					      NULL, &error);
+	if (geoclue_client == NULL) {
+		g_printerr(_("Unable to obtain GeoClue Client: %s.\n"),
+			   error->message);
+		g_error_free(error);
+		g_variant_unref(client_path_v);
+		g_object_unref(geoclue_manager);
+		return;
+	}
+
+	g_variant_unref(client_path_v);
+
+	/* Set distance threshold */
+	error = NULL;
+	GVariant *ret_v =
+		g_dbus_proxy_call_sync(geoclue_client,
+				       "org.freedesktop.DBus.Properties.Set",
+				       g_variant_new("(ssv)",
+						     "org.freedesktop.GeoClue2.Client",
+						     "DistanceThreshold",
+						     g_variant_new("u", 50000)),
+				       G_DBUS_CALL_FLAGS_NONE,
+				       -1, NULL, &error);
+	if (ret_v == NULL) {
+		g_printerr(_("Unable to set distance threshold: %s.\n"),
+			   error->message);
+		g_error_free(error);
+		g_object_unref(geoclue_client);
+		g_object_unref(geoclue_manager);
+		return;
+	}
+
+	g_variant_unref(ret_v);
+
+	/* Attach signal callback to client */
+	g_signal_connect(geoclue_client, "g-signal",
+			 G_CALLBACK(geoclue_client_signal_cb),
+			 data);
+
+	/* Start GeoClue client */
+	error = NULL;
+	ret_v = g_dbus_proxy_call_sync(geoclue_client,
+				       "Start",
+				       NULL,
+				       G_DBUS_CALL_FLAGS_NONE,
+				       -1, NULL, &error);
+	if (ret_v == NULL) {
+		g_printerr(_("Unable to start GeoClue client: %s.\n"),
+			   error->message);
+		g_error_free(error);
+		g_object_unref(geoclue_client);
+		g_object_unref(geoclue_manager);
+		return;
+	}
+
+	g_variant_unref(ret_v);
+}
+
+/* Callback when GeoClue disappears from the bus */
+static void
+on_name_vanished(GDBusConnection *connection, const gchar *name,
+		 gpointer user_data)
+{
+	get_location_data_t *data = (get_location_data_t *)user_data;
+
+	g_fprintf(stderr, _("Unable to connect to GeoClue.\n"));
+
+	g_main_loop_quit(data->loop);
+}
+
+int
+location_geoclue2_get_location(void *state,
+			       float *lat, float *lon)
+{
+	get_location_data_t data;
+	data.available = 0;
+
+	guint watcher_id = g_bus_watch_name(G_BUS_TYPE_SYSTEM,
+					    "org.freedesktop.GeoClue2",
+					    G_BUS_NAME_WATCHER_FLAGS_AUTO_START,
+					    on_name_appeared,
+					    on_name_vanished,
+					    &data, NULL);
+	data.loop = g_main_loop_new(NULL, FALSE);
+	g_main_loop_run(data.loop);
+
+	g_bus_unwatch_name(watcher_id);
+
+	if (!data.available) return -1;
+
+	*lat = data.latitude;
+	*lon = data.longitude;
+
+	return 0;
+}