To tie signals to a specific function in your PHP-GTK 1 code, you could use connect, connect_object, connect_after or connect_object_after. The functionality of connect_object, in particular, wasn't clear at first sight.

Following some changes made in the GTK signals API, the decision was taken to rename connect_object to connect_simple and connect_object_after to connect_simple_after in PHP-GTK 2. Simple here means that you have fewer function parameters because the object itself is missing from them - something that connect_object meant, but did not imply.