[Urwid] How do you use SimpleListWalker?

[Dominic LoBue]

Hello,

I'm writing an email reader with urwid, but I'm confused as to how the
SimpleListWalker class works. Is it just a metaclass that you can
extend to make writing your own custom listwalker easier, or should
you be able to use it on its own?

Also, what's the difference between SimpleListWalker and
PollingListWalker? My application is going to thread emails and the
index view is going to show conversations (like gmail), with
conversations with recent activity pushed to the top, so I'm not sure
which walker is more appropriate, or if its even necessary to bother
with.

Keep up the good work with urwid!

Dominic