[Interest] Place a QWidget below a button (and follow it!)

[Sensei]

Hi all!

I am trying to "attach" a widget to a button inside a main window, 
making it follow any movement of the entire window.

In details, I have a widget that will display a floating window when the 
user clicks on a QToolButton. This floating widget must be placed below 
the button that summoned its soul, and if the main window moves, the 
floating window must be positioned in the same place.

In other words, I'd like to place this widget *relative* to another 
widget (inside a main window). This placement should follow every 
movement of the main window.

The entire hierarchy (pertinent to my problem) is as follows:

QMainWindow
   QSplitter
     QWidget
       QStackedWidget
          QListWidget
          QTreeWidget
          QWidget <------- My custom widget
             QToolButton
             QWidget <---- The floating window

Erroneously, I imagined that it could be sufficient to reimplement 
moveEvent in my custom widget, but what I did find? That it isn't 
actually called, instead I should, probably, reimplement the moveEvent 
in the QMainWindow and propagate the event to the custom widget (which 
in turn will move the floating window).

However, this is quite contorted and probably unnecessary.


Any hints?


Thanks & Cheers!