Adds the @callback_symbol to the scope of @builder under the
given @callback_name.
Using this function overrides the behavior of
[method@Gtk.Builder.create_closure] for any callback symbols that
are added. Using this method allows for better encapsulation as it
does not require that callback symbols be declared in the global
namespace.
Adds the @callback_symbol to the scope of @builder under the given @callback_name.
Using this function overrides the behavior of [method@Gtk.Builder.create_closure] for any callback symbols that are added. Using this method allows for better encapsulation as it does not require that callback symbols be declared in the global namespace.