Add XMonad.Layout.PerScreen

XMonad/Layout/PerScreen.hs

@@ -0,0 +1,74 @@
+{-# LANGUAGE FlexibleInstances, MultiParamTypeClasses #-}
+
+-----------------------------------------------------------------------------
+-- |
+-- Module      :  XMonad.Layout.PerScreen
+-- Copyright   :  (c) Edward Z. Yang
+-- License     :  BSD-style (see LICENSE)
+--
+-- Maintainer  :  <ezyang@cs.stanford.edu>
+-- Stability   :  unstable
+-- Portability :  unportable
+--
+-- Configure layouts based on the width of your screen; use your
+-- favorite multi-column layout for wide screens and a full-screen
+-- layout for small ones.
+-----------------------------------------------------------------------------
+
+module XMonad.Layout.PerScreen
+    ( -- * Usage
+      -- $usage
+      PerScreen,
+      ifWider
+    ) where
+
+import XMonad
+import qualified XMonad.StackSet as W
+
+import Data.Maybe (fromMaybe)
+
+-- $usage
+-- You can use this module by importing it into your ~\/.xmonad\/xmonad.hs file:
+--
+-- > import XMonad.Layout.PerScreen
+--
+-- and modifying your layoutHook as follows (for example):
+--
+-- > layoutHook = ifWider 1280 (Tall 1 (3/100) (1/2) ||| Full) Full
+--
+-- Replace any of the layouts with any arbitrarily complicated layout.
+-- ifWider can also be used inside other layout combinators.
+
+ifWider :: (LayoutClass l1 a, LayoutClass l2 a)
+               => Dimension   -- ^ target screen width
+               -> (l1 a)      -- ^ layout to use when the screen is wide enough
+               -> (l2 a)      -- ^ layout to use otherwise
+               -> PerScreen l1 l2 a
+ifWider w = PerScreen w False
+
+data PerScreen l1 l2 a = PerScreen Dimension Bool (l1 a) (l2 a) deriving (Read, Show)
+
+-- | Construct new PerScreen values with possibly modified layouts.
+mkNewPerScreenT :: PerScreen l1 l2 a -> Maybe (l1 a) ->
+                      PerScreen l1 l2 a
+mkNewPerScreenT (PerScreen w _ lt lf) mlt' =
+    (\lt' -> PerScreen w True lt' lf) $ fromMaybe lt mlt'
+
+mkNewPerScreenF :: PerScreen l1 l2 a -> Maybe (l2 a) ->
+                      PerScreen l1 l2 a
+mkNewPerScreenF (PerScreen w _ lt lf) mlf' =
+    (\lf' -> PerScreen w False lt lf') $ fromMaybe lf mlf'
+
+instance (LayoutClass l1 a, LayoutClass l2 a, Show a) => LayoutClass (PerScreen l1 l2) a where
+    runLayout (W.Workspace i p@(PerScreen w _ lt lf) ms) r
+        | rect_width r > w    = do (wrs, mlt') <- runLayout (W.Workspace i lt ms) r
+                                   return (wrs, Just $ mkNewPerScreenT p mlt')
+        | otherwise           = do (wrs, mlt') <- runLayout (W.Workspace i lf ms) r
+                                   return (wrs, Just $ mkNewPerScreenF p mlt')
+
+    handleMessage (PerScreen w bool lt lf) m
+        | bool      = handleMessage lt m >>= maybe (return Nothing) (\nt -> return . Just $ PerScreen w bool nt lf)
+        | otherwise = handleMessage lf m >>= maybe (return Nothing) (\nf -> return . Just $ PerScreen w bool lt nf)
+
+    description (PerScreen _ True  l1 _) = description l1
+    description (PerScreen _ _     _ l2) = description l2

xmonad-contrib.cabal

@@ -252,6 +252,7 @@ library
                         XMonad.Layout.NoFrillsDecoration
                         XMonad.Layout.OnHost
                         XMonad.Layout.OneBig
+                        XMonad.Layout.PerScreen
                         XMonad.Layout.PerWorkspace
                         XMonad.Layout.PositionStoreFloat
                         XMonad.Layout.Reflect