+ /*
+ * A "hidden" trigger is a trigger that is not externally listed.
+ * It is used to hide triggers that are used internally by the session
+ * daemon so that they can't be listed nor unregistered by external
+ * clients.
+ *
+ * This is a property that can only be set internally by the session
+ * daemon. As such, it is not serialized nor set by a
+ * "create_from_buffer" constructor.
+ *
+ * The hidden property is preserved by copies.
+ *
+ * Note that notifications originating from an "hidden" trigger will not
+ * be sent to clients that are not within the session daemon's process.
+ */
+ bool is_hidden;
+