How to catch the event of QToolBar when change its area

When a toolbar add to mainwindow, user can drag and drop it to change area (BottomToolBarArea, TopToolBarArea, ...)

How to catch the event when it changes area?
I tried all available signals of QToolBar but it's not working.

Thanks.

I found your issue by searching how to prevent the toolbar to desappear by clicking on the context menu...
Add the slot for the "orientationChanged" signal to your main window.
If you works with designer and your toolbar name is "toolBar",
add the on_toolBar_orientationChanged ( Qt::Orientation) Slot to the main window class.
I have tested, it works.

Doesnt QToolBar::allowedAreasChanged help you ??