On Tue, Jun 5, 2012 at 8:04 PM, Evan Driscoll <driscoll@cs.wisc.edu> wrote:
A short version which suffices: is it possible to set up a keybinding to change the keybindings?

The direct way is impossible, I'm afraid; you can't change the keybindings dynamically.  You can change what a bound key *does* dynamically, though:  given your example
 
Mod-5 would choose between the desktops for project A. Then Mod-F2 would change to project B, and Mod-1 through Mod-5 would choose between the desktops for Project B.

it is possible for the mod-1 binding to check what workspace is current, or possibly check something in ExtendedState, to determine what it should do.  http://xmonad.org/xmonad-docs/xmonad-contrib/XMonad-Actions-PerWorkspaceKeys.html automates the former.

--
brandon s allbery                                      allbery.b@gmail.com
wandering unix systems administrator (available)     (412) 475-9364 vm/sms