How to get an event on block resizing ?

Hi everybody,

I'm trying to catch an event after (during?) the resizing of a block. I know there are Observers and Responders. I found the serviceID for document handling, for example. But what is the one for a block resizing, a block moving, etc ?

I found a nice snippet called DocWatch, but I can't find any solution in it. Any idea ?

Thanks in advance

Rémi