| GTK+ Reference Manual |
|---|
libunique offers 'unique application' support as well as ways to communicate with a running application instance. This is implemented in various ways, either using D-Bus, or socket-based communication.
Starting with GLib 2.26, D-Bus support has been integrated into GIO in the form of GDBus, and GApplication has been added to provide the same level of application support as libunique.
Example 68. A unique application
Here is a simple application using libunique:
int
main (int argc, char *argv[])
{
UniqueApp *app;
GtkWidget *window;
gtk_init (&argc, &argv);
app = unique_app_new ("org.gtk.TestApplication", NULL);
if (unique_app_is_running (app))
{
UniqueResponse response;
response = unique_app_send_message (app, UNIQUE_ACTIVATE, NULL);
g_object_unref (app);
return response == UNIQUE_RESPONSE_OK ? 0 : 1;
}
window = create_my_window ();
unique_app_watch_window (app, GTK_WINDOW (window));
gtk_widget_show (window);
gtk_main ();
g_object_unref (app);
return 0;
}
The same application using GtkApplication:
static void
activate (GtkApplication *app)
{
GtkWidget *window;
window = create_my_window ();
gtk_window_set_application (GTK_WINDOW (window), app);
gtk_widget_show (window);
}
int
main (int argc, char *argv[])
{
GtkApplication *app;
gint status;
app = gtk_application_new ("org.gtk.TestApplication", 0);
g_signal_connect (app, "activate", G_CALLBACK (activate), NULL);
status = g_application_run (app);
g_object_unref (app);
return status;
}
Instead of creating a UniqueApp with unique_app_new(), create
a GApplication with g_application_new() or a GtkApplication
with gtk_application_new(). The name that was used with
unique_app_new() is very likely usable as the application_id for
g_application_new() without any changes, and GtkApplication passes
the DESKTOP_STARTUP_ID environment variable
automatically.
While libunique expects you to check for an already running instance
yourself and activate it manually, GApplication handles all this on
its own in g_application_run(). If you still need to find out if there
is a running instance of your application, use
g_application_get_is_remote() instead of unique_app_is_running().