property_text()=(Glib::ustring)time.get_string(fps,App::get_time_format());
CellRendererText::render_vfunc(window,widget,background_area,ca,expose_area,flags);
property_text()=(Glib::ustring)time.get_string(fps,App::get_time_format());
CellRendererText::render_vfunc(window,widget,background_area,ca,expose_area,flags);