-----------------------------------------------------------------------------
-- |
-- Module : XMonadContrib.LayoutHelpers
-- 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.LayoutHelpers (
-- * Usage
-- $usage
DoLayout, ModDo, ModMod, ModLay,
layoutModify,
l2lModDo, idModify,
idModDo, idModMod,
) where
import Graphics.X11.Xlib ( Rectangle )
import XMonad
import StackSet ( Stack, integrate )
-- $usage
-- Use LayoutHelpers to help write easy Layouts.
type DoLayout a = Rectangle -> Stack a -> X ([(a, Rectangle)], Maybe (Layout a))
type ModifyLayout a = SomeMessage -> X (Maybe (Layout a))
type ModDo a = Rectangle -> Stack a -> [(a, Rectangle)] -> X ([(a, Rectangle)], Maybe (ModLay a))
type ModMod a = SomeMessage -> X (Maybe (ModLay a))
type ModLay a = Layout a -> Layout a
layoutModify :: ModDo a -> ModMod a -> ModLay a
layoutModify fdo fmod l = Layout { doLayout = dl, modifyLayout = modl }
where dl r s = do (ws, ml') <- doLayout l r s
(ws', mmod') <- fdo r s ws
let ml'' = case mmod' of
Just mod' -> Just $ mod' $ maybe l id ml'
Nothing -> layoutModify fdo fmod `fmap` ml'
return (ws', ml'')
modl m = do ml' <- modifyLayout l m
mmod' <- fmod m
return $ case mmod' of
Just mod' -> Just $ mod' $ maybe l id ml'
Nothing -> layoutModify fdo fmod `fmap` ml'
l2lModDo :: (Rectangle -> [a] -> [(a,Rectangle)]) -> DoLayout a
l2lModDo dl r s = return (dl r $ integrate s, Nothing)
idModDo :: ModDo a
idModDo _ _ wrs = return (wrs, Nothing)
idModify :: ModifyLayout a
idModify _ = return Nothing
idModMod :: ModMod a
idModMod _ = return Nothing
