Close/destroy event propagation

[Fabrizio Pollastri]

Hi all,

in my application, I need to trigger a function when a widget (i.e. a wx.Button) 
is closed/destroyed for any reason: the parent top level window is closed, a 
parent widget (not the top level window) containing the widget is destroyed, the 
widget itself is destroyed.
What kind of event(s) I need to bind to the widget to catch any close/destroy 
event on any parent widget or on the widget itself?
Thank you in advance for any help.

F. Pollastri