Function gtk_font_dialog_choose_face 

pub unsafe extern "C" fn gtk_font_dialog_choose_face(
    self_: *mut GtkFontDialog,
    parent: *mut GtkWindow,
    initial_value: *mut PangoFontFace,
    cancellable: *mut GCancellable,
    callback: GAsyncReadyCallback,
    user_data: gpointer,
)