+/** If this Tabbable is currently parented by a tab, ensure that the tab is the
+ * current one. If it is parented by a window, then toggle the visibility of
+ * that window.
+ */
+void
+Tabbable::change_visibility ()
+{
+ if (tabbed()) {
+ _parent_notebook->set_current_page (_parent_notebook->page_num (_contents));
+ return;
+ }
+
+ if (tab_requested_by_state) {
+ /* should be tabbed, but currently isn't parented by a notebook */
+ return;
+ }
+
+ if (_window && (current_toplevel() == _window)) {
+ /* Use WindowProxy method which will rotate then hide */
+ toggle();
+ }
+}
+
+void
+Tabbable::make_visible ()