The GtkBuilderConnectFunc to use when connecting signals in the class template
The data to pass to connect_func
The GDestroyNotify to free connect_data, this will only be used at class finalization time, when no classes of type widget_type are in use anymore. Since 3.10
For use in lanuage bindings, this will override the default GtkBuilderConnectFunc to be used when parsing GtkBuilder xml from this class's template data. Note This must be called from a composite widget classes class initializer after calling gtk_widget_class_set_template()