Created attachment 183372 [details] [review]
gio-2.0 and codegen: Support for manual dbus object registration

Added the new GIO function DBusConnection.register_object_vtable
it allows to register a dbus object using the manual GDBus registration
via interface info and interface vtable.

An implementation example follows:

const string introspection_xml =
"""<node>
  <interface name='org.example.ManualObject'>
    <method name='Hello'>"
      <arg type='s' name='greeting' direction='in'/>
      <arg type='s' name='response' direction='out'/>
    </method>"
  </interface>
</node>""";

const GLib.DBusInterfaceVTable ivtable = { method_call, null, null };
public void method_call(GLib.DBusConnection connection, string sender, string object_path, string interface_name, string method_name, GLib.Variant parameters, GLib.DBusMethodInvocation invocation) {
	var s = @"Method $interface_name.$method_name called on $object_path with parameters:\n$(parameters.print(true))";
	print(s+"\n");

	invocation.return_value(new Variant("(s)", s));
}

void on_bus_aquired (DBusConnection conn) {
	try {
		var iface_node = new DBusNodeInfo.for_xml(introspection_xml);
		var iface_info = iface_node.lookup_interface("org.example.ManualObject");
		conn.register_object_vtable ("/org/example/demo/manual_object", iface_info, ivtable);
	} catch (Error e) {
		stderr.printf (@"Could not register service $(e.message)\n");
	}
}

void main () {
	Bus.own_name (BusType.SESSION, "org.example.Demo", BusNameOwnerFlags.NONE,
	                on_bus_aquired,
	                () => {},
	                () => stderr.printf ("Could not aquire name\n"));

	new MainLoop ().run ();
}