add XMonad.Actions.CycleSelectedLayouts

darcs-hash:20080116205020-3ebed-4cbcc5e67871dddb863909b153205417ebe1ce94.gz

1 files changed, 51 insertions, 0 deletions

diff --git a/XMonad/Actions/CycleSelectedLayouts.hs b/XMonad/Actions/CycleSelectedLayouts.hs
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+++ b/XMonad/Actions/CycleSelectedLayouts.hs
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+-----------------------------------------------------------------------------
+-- |
+-- Module      :  XMonad.Actions.CycleSelectedLayouts
+-- Copyright   :  (c) Roman Cheplyaka
+-- License     :  BSD3-style (see LICENSE)
+--
+-- Maintainer  :  Roman Cheplyaka <roma@ro-che.info>
+-- Stability   :  unstable
+-- Portability :  unportable
+--
+-- This module allows to cycle through the given subset of layouts.
+--
+-----------------------------------------------------------------------------
+
+module XMonad.Actions.CycleSelectedLayouts (
+    -- * Usage
+    -- $usage
+    cycleThroughLayouts) where
+
+import XMonad
+import Data.List (findIndex)
+import Data.Maybe (fromMaybe)
+import XMonad.Layout.LayoutCombinators (JumpToLayout(..))
+import qualified XMonad.StackSet as S
+
+-- $usage
+-- You can use this module with the following in your @~\/.xmonad\/xmonad.hs@:
+-- 
+-- > import XMonad hiding ((|||))
+-- > import XMonad.Layout.LayoutCombinators ((|||))
+-- > import XMonad.Actions.CycleSelectedLayouts
+--
+-- >   , ((modMask x,  xK_t ),   cycleThroughLayouts ["Tall", "Mirror Tall"])
+--
+-- Make sure you are using NewSelect from XMonad.Layout.LayoutCombinators,
+-- rather than the Select defined in xmonad core.
+
+cycleToNext :: (Eq a) => [a] -> a -> Maybe a
+cycleToNext lst a = do
+    -- not beautiful but simple and readable
+    ind <- findIndex (a==) lst
+    return $ lst !! if ind == length lst - 1 then 0 else ind+1
+
+-- | If the current layout is in the list, cycle to the next layout. Otherwise,
+--   apply the first layout from list.
+cycleThroughLayouts :: [String] -> X ()
+cycleThroughLayouts lst = do
+    winset <- gets windowset
+    let ld = description . S.layout . S.workspace . S.current $ winset
+    let newld = fromMaybe (head lst) (cycleToNext lst ld)
+    sendMessage $ JumpToLayout newld