gtk:label-pattern (object)

object -- a gtk:label widget you want to set the pattern to
pattern -- a string for the pattern as described below

The accessor for the pattern slot sets the pattern of underlines you want under the existing text within the label. For example, if the current text of the label says "FooBarBaz" passing a pattern of "___ ___" will underline "Foo" and "Baz" but not "Bar".