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/*
* Gypsy
*
* A simple to use and understand GPSD replacement
* that uses D-Bus, GLib and memory allocations
*
* Author: Iain Holmes <iain@gnome.org>
* Copyright (C) 2007
*
* This example code is in the public domain.
*/
/*
* simple-gps-dbus: A simple gps example using pure D-Bus.
*/
#include <glib.h>
#define DBUS_API_SUBJECT_TO_CHANGE
#include <dbus/dbus-glib.h>
#include <dbus/dbus-glib-lowlevel.h>
#include <dbus/dbus.h>
static DBusHandlerResult
parse_position_changed (DBusConnection *conn,
DBusMessage *message,
void *user_data)
{
int timestamp, fields;
double latitude, longitude, altitude;
DBusError error;
dbus_error_init (&error);
if (!dbus_message_get_args (message, &error,
DBUS_TYPE_INT32, &fields,
DBUS_TYPE_INT32, ×tamp,
DBUS_TYPE_DOUBLE, &latitude,
DBUS_TYPE_DOUBLE, &longitude,
DBUS_TYPE_DOUBLE, &altitude,
DBUS_TYPE_INVALID)) {
g_warning ("Could not get position: %s", error.message);
dbus_error_free (&error);
return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
}
g_print ("Latitude: %f\nLongitude: %f\nAltitude: %f\n",
latitude, longitude, altitude);
return DBUS_HANDLER_RESULT_HANDLED;
}
static DBusHandlerResult
parse_course_changed (DBusConnection *conn,
DBusMessage *message,
void *user_data)
{
int timestamp, fields;
double speed, direction, climb;
DBusError error;
dbus_error_init (&error);
if (!dbus_message_get_args (message, &error,
DBUS_TYPE_INT32, &fields,
DBUS_TYPE_INT32, ×tamp,
DBUS_TYPE_DOUBLE, &speed,
DBUS_TYPE_DOUBLE, &direction,
DBUS_TYPE_DOUBLE, &climb,
DBUS_TYPE_INVALID)) {
g_warning ("Could not get position: %s", error.message);
dbus_error_free (&error);
return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
}
g_print ("Speed: %f\nDirection: %f\nClimb: %f\n",
speed, direction, climb);
return DBUS_HANDLER_RESULT_HANDLED;
}
static DBusHandlerResult
signal_filter (DBusConnection *conn,
DBusMessage *message,
void *user_data)
{
if (dbus_message_is_signal (message, "org.freedesktop.gypsy.Client",
"PositionChanged")) {
return parse_position_changed (conn, message, user_data);
}
if (dbus_message_is_signal (message, "org.freedesktop.gypsy.Client",
"CourseChanged")) {
return parse_course_changed (conn, message, user_data);
}
return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
}
static DBusConnection *
get_connection (void)
{
GError *error = NULL;
DBusGConnection *conn;
conn = dbus_g_bus_get (DBUS_BUS_SYSTEM, &error);
if (conn == NULL) {
g_error ("Error getting bus: %s", error->message);
}
return dbus_g_connection_get_connection (conn);
}
#define POSITION_CHANGED_MATCH "type='signal',interface='org.freedesktop.gypsy.Client',member='PositionChanged'"
#define COURSE_CHANGED_MATCH "type='signal',interface='org.freedesktop.gypsy.Client',member='CourseChanged'"
int
main (int argc,
char **argv)
{
DBusConnection *conn;
DBusError error;
GMainLoop *mainloop;
g_type_init ();
conn = get_connection ();
dbus_error_init (&error);
dbus_bus_add_match (conn, POSITION_CHANGED_MATCH, &error);
if (dbus_error_is_set (&error)) {
g_error ("Error adding match: %s", error.message);
}
dbus_bus_add_match (conn, COURSE_CHANGED_MATCH, &error);
if (dbus_error_is_set (&error)) {
g_error ("Error adding match: %s", error.message);
}
if (!dbus_connection_add_filter (conn, signal_filter,
NULL, NULL)) {
g_error ("Error adding filter");
}
mainloop = g_main_loop_new (NULL, FALSE);
g_main_loop_run (mainloop);
return 0;
}
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