[Xmonad] Three column layout

[David Roundy]

On Sat, Jul 21, 2007 at 10:43:26PM +0200, Kai Grossjohann wrote:
> On Sat, Jul 21, 2007 at 04:56:16PM +0200, Kai Grossjohann wrote:
> 
> > Below, please find a patch that implements a three column layout.
> > Beware that I don't know Haskell at all.  It seems to work for me, but I
> > am surprised.
> 
> Improved version below.
> 
> This behaves very strangely when increasing nmaster.  It seems that 3col
> layout then disappears completely, or behaves like 2col.  Do others see
> this, too?  Why?
...
> +threeCol :: Int -> Rational -> Rational -> Layout a
> +threeCol nmaster delta frac =
> +    Layout { doLayout     = \r -> return . (\x->(x,Nothing)) .
> +                                  ap zip (tile3 frac r nmaster . length) . W.integrate
> +           , modifyLayout = \m -> return $ msum [fmap resize     (fromMessage m)
> +                                                ,fmap incmastern (fromMessage m)] }
> +
> +    where resize Shrink = tall nmaster delta (max 0 $ frac-delta)
> +          resize Expand = tall nmaster delta (min 1 $ frac+delta)
> +          incmastern (IncMasterN d) = tall (max 0 (nmaster+d)) delta frac

Your response to resize and incmaster events is to switch to a "tall"
layout.  Replace the above talls with threeCol and this should be fixed.
-- 
David Roundy
http://www.darcs.net