`GtkFileFilter` filters files by name or mime type.
`GtkFileFilter` can be used to restrict the files being shown in a `GtkFileChooser`. Files can be filtered based on their name (with [ method@Gtk.FileFilter.add_pattern]) or on their mime type (with [method@Gtk.FileFilter.add_mime_type]).
Filtering by mime types handles aliasing and subclassing of mime types; e.g. a filter for text/plain also matches a file with mime type application/rtf, since application/rtf is a subclass of text/plain. Note that `GtkFileFilter` allows wildcards for the subtype of a mime type, so you can e.g. filter for image/\*.
Normally, file filters are used by adding them to a `GtkFileChooser` (see [method@Gtk.FileChooser.add_filter]), but it is also possible to manually use a file filter on any [class@Gtk.FilterListModel] containing `GFileInfo` objects.
GtkFileFilter as GtkBuildable
The `GtkFileFilter` implementation of the `GtkBuildable` interface supports adding rules using the <mime-types> and <patterns> elements and listing the rules within. Specifying a <mime-type> or <pattern> has the same effect as as calling [ method@Gtk.FileFilter.add_mime_type] or [method@Gtk.FileFilter.add_pattern].
An example of a UI definition fragment specifying `GtkFileFilter` rules: ```xml <object class="GtkFileFilter"> <property name="name" translatable="yes">Text and Images</property> <mime-types> <mime-type>text/plain</mime-type> <mime-type> image/ *</mime-type> </mime-types> <patterns> <pattern>*.txt</pattern> <pattern>*.png</pattern> </patterns> </object> ```