[xmonad] xinerama and per-screen automatic layout modification

[adam vogt]

Hi Steffen,

I think it is simpler to check if the screen has height > width, and
then do what Mirror does if that happens to be the case. The following
code is a slight modification of the code for Mirror probably does
that (it compiles but I have not tested it):

{-# LANGUAGE MultiParamTypeClasses #-} -- at the top of the file
{-# LANGUAGE FlexibleInstances #-}

import XMonad
import Control.Arrow
import qualified XMonad.StackSet as W

-- | Mirror a layout, compute its 90 degree rotated form.
newtype MirrorAspect l a = MirrorAspect (l a) deriving (Show, Read)

instance LayoutClass l a => LayoutClass (MirrorAspect l) a where
    runLayout (W.Workspace i (MirrorAspect l) ms) r@(Rectangle _ _ w h)
        = (map (second mirrorRect) *** fmap MirrorAspect)
            `fmap` runLayout (W.Workspace i l ms) (mirrorRect r)
      where
          -- | possibly Mirror a rectangle
          mirrorRect :: Rectangle -> Rectangle
          mirrorRect r0@(Rectangle rx ry rw rh)
              | h > w = Rectangle ry rx rh rw
              | otherwise = r0
    handleMessage (MirrorAspect l) = fmap (fmap MirrorAspect) . handleMessage l
    description (MirrorAspect l) = "MirrorAspect "++ description l



Regards,
Adam