Hi,

As an alteration to Sawfish's "shade-hover" mode, I've written a bit of
code that shades and unshades a window when it gains and loses the
focus.  Hitting the "shade" button on a temporarily-unshaded window will
set it to be permanently unshaded.  It does this by exploiting the fact
that a window's "shade" property has a slightly odd relationship with
the actual shaded state of a window (which, if not deliberate, I'd like
filed as a non-bug :).

I suspect Sawfish's "shade-hover" mode is used mostly by people who
prefer the focus to be updated on window-enter and window-exit (I
prefer window-enter only).  If so, shade-focus can be seen as a
generalisation of shade-hover, because they behave exactly the same with
enter-exit focus switching.

The code isn't that aesthetically pleasing - I've been using the WM for
less than a week, so I'm not fully up on the guts of the system yet :)
It works, though.  An interesting extension would be allow windows to
individually choose between "shade-hover", "shade-focus" and "no
auto-shading", but that kind of thing is way beyond my current abilities
:)