diff options
| -rw-r--r-- | XMonad/Layout/MultiToggle.hs | 123 |
1 files changed, 102 insertions, 21 deletions
diff --git a/XMonad/Layout/MultiToggle.hs b/XMonad/Layout/MultiToggle.hs index a411b84..0cd6ab4 100644 --- a/XMonad/Layout/MultiToggle.hs +++ b/XMonad/Layout/MultiToggle.hs @@ -9,34 +9,110 @@ -- Maintainer : <l.mai@web.de> -- Stability : unstable -- Portability : unportable +-- +-- Dynamically apply and unapply transformers to your window layout. This can +-- be used to rotate your window layout by 90 degrees, or to make the +-- currently focused window occupy the whole screen (\"zoom in\") then undo +-- the transformation (\"zoom out\"). module XMonad.Layout.MultiToggle ( - EL(..), - unEL, - LayoutTransformer(..), + -- * Usage + -- $usage + Transformer(..), Toggle(..), - (.*.), - HNil(..), + (??), + EOT(..), mkToggle ) where - import XMonad import Control.Arrow import Data.Typeable import Data.Maybe +-- $usage +-- The basic idea is to have a base layout and a set of layout transformers, +-- of which at most one is active at any time. Enabling another transformer +-- first disables any currently active transformer; i.e. it works like a +-- group of radio buttons. +-- +-- A side effect of this meta-layout is that layout transformers no longer +-- receive any messages; any message not handled by SwitchTrans itself will +-- undo the current layout transformer, pass the message on to the base +-- layout, then reapply the transformer. +-- +-- To use this module, you first have to define the transformers that you +-- want to be handled by @MultiToggle@. For example, if the transformer is +-- 'XMonad.Layouts.Mirror': +-- +-- > data MIRROR = MIRROR deriving (Read, Show, Eq, Typeable) +-- > instance Transformer MIRROR Window where +-- > transform _ x k = k (Mirror x) +-- +-- @MIRROR@ can be any identifier (it has to start with an uppercase letter, +-- of course); I've chosen an all-uppercase version of the transforming +-- function's name here. You need to put @{-\# OPTIONS_GHC -fglasgow-exts \#-}@ +-- at the beginning of your file to be able to derive "Data.Typeable". +-- +-- Somewhere else in your file you probably have a definition of @layout@; +-- the default looks like this: +-- +-- > layout = tiled ||| Mirror tiled ||| Full +-- +-- After changing this to +-- +-- > layout = mkToggle (MIRROR ?? EOT) (tiled ||| Full) +-- +-- you can now dynamically apply the 'XMonad.Layouts.Mirror' transformation: +-- +-- > ... +-- > , ((modMask, xK_x ), sendMessage $ Toggle MIRROR) +-- > ... +-- +-- (That should be part of your key bindings.) When you press @mod-x@, the +-- active layout is mirrored. Another @mod-x@ and it's back to normal. +-- +-- It's also possible to stack @MultiToggle@s. Let's define a few more +-- transformers ('XMonad.Layout.NoBorders.noBorders' is in +-- "XMonad.Layout.NoBorders"): +-- +-- > data NOBORDERS = NOBORDERS deriving (Read, Show, Eq, Typeable) +-- > instance Transformer NOBORDERS Window where +-- > transform _ x k = k (noBorders x) +-- > +-- > data FULL = FULL deriving (Read, Show, Eq, Typeable) +-- > instance Transformer FULL Window where +-- > transform _ x k = k Full +-- +-- @ +-- layout = id +-- . 'XMonad.Layout.NoBorders.smartBorders' +-- . mkToggle (NOBORDERS ?? FULL ?? EOT) +-- . mkToggle (MIRROR ?? EOT) +-- $ tiled ||| 'XMonad.Layout.Grid.Grid' ||| 'XMonad.Layout.Circle.Circle' +-- @ +-- +-- By binding a key to @(sendMessage $ Toggle FULL)@ you can temporarily +-- maximize windows, in addition to being able to rotate layouts and remove +-- window borders. + +-- | A class to identify custom transformers (and look up transforming +-- functions by type). +class (Eq t, Typeable t) => Transformer t a | t -> a where + transform :: (LayoutClass l a) => t -> l a -> (forall l'. (LayoutClass l' a) => l' a -> b) -> b + data EL a = forall l. (LayoutClass l a) => EL (l a) unEL :: EL a -> (forall l. (LayoutClass l a) => l a -> b) -> b unEL (EL x) k = k x -class (Eq t, Typeable t) => LayoutTransformer t a | t -> a where - transform :: t -> EL a -> EL a +transform' :: (Transformer t a) => t -> EL a -> EL a +transform' t el = el `unEL` \l -> transform t l EL -data Toggle a = forall t. (LayoutTransformer t a) => Toggle t +-- | Toggle the specified layout transformer. +data Toggle a = forall t. (Transformer t a) => Toggle t deriving (Typeable) instance (Typeable a) => Message (Toggle a) @@ -56,7 +132,7 @@ expand :: (LayoutClass l a, HList ts a) => MultiToggleS ts l a -> MultiToggle ts expand (MultiToggleS b i ts) = resolve ts (fromMaybe (-1) i) id (\x mt -> - let g = transform x in + let g = transform' x in mt{ currLayout = g . EL $ baseLayout mt, currTrans = g @@ -73,25 +149,30 @@ instance (LayoutClass l a, Read (l a), HList ts a, Read ts) => Read (MultiToggle instance (Show ts, Show (l a)) => Show (MultiToggle ts l a) where showsPrec p = showsPrec p . collapse +-- | Construct a @MultiToggle@ layout from a transformer table and a base +-- layout. mkToggle :: (LayoutClass l a) => ts -> l a -> MultiToggle ts l a mkToggle ts l = MultiToggle l (EL l) Nothing id ts -data HNil = HNil deriving (Read, Show) +-- | Marks the end of a transformer list. +data EOT = EOT deriving (Read, Show) data HCons a b = HCons a b deriving (Read, Show) -infixr 0 .*. -(.*.) :: (HList b w) => a -> b -> HCons a b -(.*.) = HCons +infixr 0 ?? +-- | Prepend an element to a heterogenuous list. Used to build transformer +-- tables for 'mkToggle'. +(??) :: (HList b w) => a -> b -> HCons a b +(??) = HCons class HList c a where - find :: (LayoutTransformer t a) => c -> t -> Maybe Int - resolve :: c -> Int -> b -> (forall t. (LayoutTransformer t a) => t -> b) -> b + find :: (Transformer t a) => c -> t -> Maybe Int + resolve :: c -> Int -> b -> (forall t. (Transformer t a) => t -> b) -> b -instance HList HNil w where - find HNil _ = Nothing - resolve HNil _ d _ = d +instance HList EOT w where + find EOT _ = Nothing + resolve EOT _ d _ = d -instance (LayoutTransformer a w, HList b w) => HList (HCons a b) w where +instance (Transformer a w, HList b w) => HList (HCons a b) w where find (HCons x xs) t | t `geq` x = Just 0 | otherwise = fmap succ (find xs t) @@ -129,7 +210,7 @@ instance (Typeable a, Show ts, HList ts a, LayoutClass l a) => LayoutClass (Mult } else do handleMessage l (SomeMessage ReleaseResources) - let f = transform t + let f = transform' t return . Just $ mt{ currLayout = f . EL $ baseLayout mt, |