public class StringFilter : Filter
`GtkStringFilter` determines whether to include items by comparing strings to a fixed search term.
The strings are obtained from the items by evaluating a `GtkExpression` set with [method@Gtk.StringFilter.set_expression], and they are compared against a search term set with [method@Gtk.StringFilter.set_search].
`GtkStringFilter` has several different modes of comparison - it can match the whole string, just a prefix, or any substring. Use [ method@Gtk.StringFilter.set_match_mode] choose a mode.
It is also possible to make case-insensitive comparisons, with [method@Gtk.StringFilter.set_ignore_case].