qt - How to detect when a QDockWidget is moved out of a QMainWindow? -

there signal allows user know qdockwidget has been moved inside qmainwindow :

void docklocationchanged(qt::dockwidgetarea area) 

the problem signal not fired when qdockwidget moved out of qmainwindow (either dragging or double-clicking dockwidget's title bar).

is there way detect event, without reimplementing moveevent()?

there floating property purpose, , toplevelchanged signal.