Queries if model is mutable.
An immutable #GMenuModel will never emit the #GMenuModel::items-changed signal. Consumers of the model may make optimisations accordingly.
true if the model is mutable (ie: "items-changed" may be emitted).
Queries if model is mutable.
An immutable #GMenuModel will never emit the #GMenuModel::items-changed signal. Consumers of the model may make optimisations accordingly.