Increments the reference count for the interface type @g_type,
and returns the default interface vtable for the type.
If the type is not currently in use, then the default vtable
for the type will be created and initalized by calling
the base interface init and default vtable init functions for
the type (the @base_init and @class_init members of #GTypeInfo).
Calling g_type_default_interface_ref() is useful when you
want to make sure that signals and properties for an interface
have been installed.
Increments the reference count for the interface type @g_type, and returns the default interface vtable for the type.
If the type is not currently in use, then the default vtable for the type will be created and initalized by calling the base interface init and default vtable init functions for the type (the @base_init and @class_init members of #GTypeInfo). Calling g_type_default_interface_ref() is useful when you want to make sure that signals and properties for an interface have been installed.