Detect window switches?

[Joost Kremers]

Hi all,

Is there a way in Emacs to detect a window switch? Basically, I'd like
to perform an action when a window showing a particular buffer gains or
loses focus. Is there a hook or something that exposes this to Elisp?

TIA

Joost



-- 
Joost Kremers                                   joostkremers@fastmail.fm
Selbst in die Unterwelt dringt durch Spalten Licht
EN:SiS(9)