Add A.RandomBackground, actions to start terminals with a random -bg option

XMonad/Actions/RandomBackground.hs

@@ -0,0 +1,39 @@
+-----------------------------------------------------------------------------
+-- |
+-- Module      :  XMonad.Actions.RandomBackground
+-- Copyright   :  (c) 2009 Anze Slosar
+--                translation to Haskell by Adam Vogt
+-- License     :  BSD3-style (see LICENSE)
+--
+-- Maintainer  :  <vogt.adam@gmail.com>
+-- Stability   :  unstable
+-- Portability :  unportable
+--
+-- An action to start terminals with a random background color
+--
+-----------------------------------------------------------------------------
+
+module XMonad.Actions.RandomBackground (randomBg,randomBg') where
+
+import XMonad(X, XConf(config), XConfig(terminal), io, spawn,
+              MonadIO, asks)
+import System.Random(Random(randomRIO))
+import Control.Monad(replicateM)
+import Numeric(showHex)
+
+-- | randomHex produces hex values in the form @xxyyzz@, with each of @xx@,
+-- @yy@, @zz@ within the range specified. The first parameter determines the
+-- the number of such groups.
+randomHex ::  Int -> (Int, Int) -> IO String
+randomHex n = fmap disp . replicateM n . randomRIO
+    where ensure x = reverse . take x . (++repeat '0') . reverse
+          disp = concatMap $ ensure 2 . ($ "") . showHex
+
+-- | randomBg' appends the random hex @ -bg '#xxyyzz'@ to the supplied string
+randomBg' ::  (MonadIO m) => (Int, Int) -> String -> m String
+randomBg' x t = do
+  num <- io $ randomHex 3 x
+  return $ concat [t," -bg '#",num,"'"]
+
+randomBg :: (Int,Int) -> X ()
+randomBg x = spawn =<< randomBg' x =<< asks (terminal . config)

xmonad-contrib.cabal

@@ -89,6 +89,7 @@ library
                         XMonad.Actions.Plane
                         XMonad.Actions.Promote
                         XMonad.Actions.RotSlaves
+                        XMonad.Actions.RandomBackground
                         XMonad.Actions.Search
                         XMonad.Actions.SimpleDate
                         XMonad.Actions.SinkAll