{-# OPTIONS_GHC -fglasgow-exts #-} -- For deriving Data/Typeable
{-# LANGUAGE FlexibleInstances, MultiParamTypeClasses, PatternGuards #-}
-----------------------------------------------------------------------------
-- |
-- Module : XMonadContrib.ToggleLayouts
-- Copyright : (c) David Roundy <droundy@darcs.net>
-- License : BSD
--
-- Maintainer : David Roundy <droundy@darcs.net>
-- Stability : unstable
-- Portability : portable
--
-- A module for writing easy Layouts
-----------------------------------------------------------------------------
module XMonadContrib.ToggleLayouts (
-- * Usage
-- $usage
toggleLayouts, ToggleLayout(..)
) where
import XMonad
import Operations ( LayoutMessages(Hide, ReleaseResources) )
-- $usage
-- Use toggleLayouts to toggle between two layouts.
--
-- import XMonadContrib.ToggleLayouts
--
-- and add to your layoutHook something like
--
-- > layoutHook = Layout $ toggleLayouts (noBorders Full) $ Select layouts
--
-- and a key binding like
-- > , ((modMask .|. controlMask, xK_space), sendMessage ToggleLayout)
--
-- or a key binding like
-- > , ((modMask .|. controlMask, xK_space), sendMessage (Toggle "Full"))
data ToggleLayouts lt lf a = ToggleLayouts Bool (lt a) (lf a) deriving (Read,Show)
data ToggleLayout = ToggleLayout | Toggle String deriving (Read,Show,Typeable)
instance Message ToggleLayout
toggleLayouts :: (LayoutClass lt a, LayoutClass lf a) => lt a -> lf a -> ToggleLayouts lt lf a
toggleLayouts = ToggleLayouts False
instance (LayoutClass lt a, LayoutClass lf a) => LayoutClass (ToggleLayouts lt lf) a where
doLayout (ToggleLayouts True lt lf) r s = do (ws,mlt') <- doLayout lt r s
return (ws,fmap (\lt' -> ToggleLayouts True lt' lf) mlt')
doLayout (ToggleLayouts False lt lf) r s = do (ws,mlf') <- doLayout lf r s
return (ws,fmap (\lf' -> ToggleLayouts False lt lf') mlf')
description (ToggleLayouts True lt _) = description lt
description (ToggleLayouts False _ lf) = description lf
handleMessage (ToggleLayouts bool lt lf) m
| Just ReleaseResources <- fromMessage m =
do mlf' <- handleMessage lf m
mlt' <- handleMessage lt m
return $ case (mlt',mlf') of
(Nothing ,Nothing ) -> Nothing
(Just lt',Nothing ) -> Just $ ToggleLayouts bool lt' lf
(Nothing ,Just lf') -> Just $ ToggleLayouts bool lt lf'
(Just lt',Just lf') -> Just $ ToggleLayouts bool lt' lf'
handleMessage (ToggleLayouts True lt lf) m
| Just ToggleLayout <- fromMessage m = do mlt' <- handleMessage lt (SomeMessage Hide)
let lt' = maybe lt id mlt'
return $ Just $ ToggleLayouts False lt' lf
| Just (Toggle d) <- fromMessage m,
d == description lt || d == description lf =
do mlt' <- handleMessage lt (SomeMessage Hide)
let lt' = maybe lt id mlt'
return $ Just $ ToggleLayouts False lt' lf
| otherwise = do mlt' <- handleMessage lt m
return $ fmap (\lt' -> ToggleLayouts True lt' lf) mlt'
handleMessage (ToggleLayouts False lt lf) m
| Just ToggleLayout <- fromMessage m = do mlf' <- handleMessage lf (SomeMessage Hide)
let lf' = maybe lf id mlf'
return $ Just $ ToggleLayouts True lt lf'
| Just (Toggle d) <- fromMessage m,
d == description lt || d == description lf =
do mlf' <- handleMessage lf (SomeMessage Hide)
let lf' = maybe lf id mlf'
return $ Just $ ToggleLayouts True lt lf'
| otherwise = do mlf' <- handleMessage lf m
return $ fmap (\lf' -> ToggleLayouts False lt lf') mlf'
