This interface is used to denote that an object is capable of being
a completion proposal for class@Completion.
Currently, no method or functions are required but additional methods
may be added in the future. Proposals created by
#GtkSourceCompletionProvider can use func@GObject.IMPLEMENT_INTERFACE to
implement this with null for the interface init function.
Interface for completion proposals.
This interface is used to denote that an object is capable of being a completion proposal for class@Completion.
Currently, no method or functions are required but additional methods may be added in the future. Proposals created by #GtkSourceCompletionProvider can use func@GObject.IMPLEMENT_INTERFACE to implement this with null for the interface init function.