{-# LANGUAGE DeriveDataTypeable, GeneralizedNewtypeDeriving, MultiParamTypeClasses, TypeSynonymInstances #-}
-----------------------------------------------------------------------------
-- |
-- Module : XMonad.Layout.MosaicAlt
-- Copyright : (c) 2007 James Webb
-- License : BSD-style (see xmonad/LICENSE)
--
-- Maintainer : xmonad#jwebb,sygneca,com
-- Stability : unstable
-- Portability : unportable
--
-- A layout which gives each window a specified amount of screen space
-- relative to the others. Compared to the 'Mosaic' layout, this one
-- divides the space in a more balanced way.
--
-----------------------------------------------------------------------------
module XMonad.Layout.MosaicAlt (
-- * Usage:
-- $usage
MosaicAlt(..)
, shrinkWindowAlt
, expandWindowAlt
, tallWindowAlt
, wideWindowAlt
, resetAlt
) where
import XMonad
import qualified XMonad.StackSet as W
import qualified Data.Map as M
import Data.List ( sortBy )
import Data.Ratio
-- $usage
-- You can use this module with the following in your @~\/.xmonad\/xmonad.hs@:
--
-- > import XMonad.Layout.MosaicAlt
-- > import qualified Data.Map as M
--
-- Then edit your @layoutHook@ by adding the MosaicAlt layout:
--
-- > myLayout = MosaicAlt M.empty ||| Full ||| etc..
-- > main = xmonad defaultConfig { layoutHook = myLayout }
--
-- For more detailed instructions on editing the layoutHook see:
--
-- "XMonad.Doc.Extending#Editing_the_layout_hook"
--
-- In the key-bindings, do something like:
--
-- > , ((modm .|. shiftMask , xK_a ), withFocused (sendMessage . expandWindowAlt))
-- > , ((modm .|. shiftMask , xK_z ), withFocused (sendMessage . shrinkWindowAlt))
-- > , ((modm .|. shiftMask , xK_s ), withFocused (sendMessage . tallWindowAlt))
-- > , ((modm .|. shiftMask , xK_d ), withFocused (sendMessage . wideWindowAlt))
-- > , ((modm .|. controlMask, xK_space), sendMessage resetAlt)
-- > ...
--
-- For detailed instruction on editing the key binding see:
--
-- "XMonad.Doc.Extending#Editing_key_bindings".
data HandleWindowAlt =
ShrinkWindowAlt Window
| ExpandWindowAlt Window
| TallWindowAlt Window
| WideWindowAlt Window
| ResetAlt
deriving ( Typeable, Eq )
instance Message HandleWindowAlt
shrinkWindowAlt, expandWindowAlt :: Window -> HandleWindowAlt
tallWindowAlt, wideWindowAlt :: Window -> HandleWindowAlt
shrinkWindowAlt = ShrinkWindowAlt
expandWindowAlt = ExpandWindowAlt
tallWindowAlt = TallWindowAlt
wideWindowAlt = WideWindowAlt
resetAlt :: HandleWindowAlt
resetAlt = ResetAlt
data Param = Param { area, aspect :: Rational } deriving ( Show, Read )
type Params = M.Map Window Param
data MosaicAlt a = MosaicAlt Params deriving ( Show, Read )
instance LayoutClass MosaicAlt Window where
description _ = "MosaicAlt"
doLayout (MosaicAlt params) rect stack =
return (arrange rect stack params', Just $ MosaicAlt params')
where
params' = ins (W.up stack) $ ins (W.down stack) $ ins [W.focus stack] params
ins wins as = foldl M.union as $ map (`M.singleton` (Param 1 1.5)) wins
handleMessage (MosaicAlt params) msg = return $ case fromMessage msg of
Just (ShrinkWindowAlt w) -> Just $ MosaicAlt $ alter params w (4 % 5) 1
Just (ExpandWindowAlt w) -> Just $ MosaicAlt $ alter params w (6 % 5) 1
Just (TallWindowAlt w) -> Just $ MosaicAlt $ alter params w 1 (3 % 4)
Just (WideWindowAlt w) -> Just $ MosaicAlt $ alter params w 1 (5 % 4)
Just ResetAlt -> Just $ MosaicAlt M.empty
_ -> Nothing
-- Change requested params for a window.
alter :: Params -> Window -> Rational -> Rational -> Params
alter params win arDelta asDelta = case M.lookup win params of
Just (Param ar as) -> M.insert win (Param (ar * arDelta) (as * asDelta)) params
Nothing -> M.insert win (Param arDelta (1.5 * asDelta)) params
-- Layout algorithm entry point.
arrange :: Rectangle -> W.Stack Window -> Params -> [(Window, Rectangle)]
arrange rect stack params = r
where
(_, r) = findSplits 3 rect tree params
tree = makeTree (sortBy areaCompare wins) params
wins = reverse (W.up stack) ++ W.focus stack : W.down stack
areaCompare a b = or1 b `compare` or1 a
or1 w = maybe 1 area $ M.lookup w params
-- Recursively group windows into a binary tree. Aim to balance the tree
-- according to the total requested area in each branch.
data Tree = Node (Rational, Tree) (Rational, Tree) | Leaf Window | None
makeTree :: [Window] -> Params -> Tree
makeTree wins params = case wins of
[] -> None
[x] -> Leaf x
_ -> Node (aArea, makeTree aWins params) (bArea, makeTree bWins params)
where ((aWins, aArea), (bWins, bArea)) = areaSplit params wins
-- Split a list of windows in half by area.
areaSplit :: Params -> [Window] -> (([Window], Rational), ([Window], Rational))
areaSplit params wins = gather [] 0 [] 0 wins
where
gather a aa b ba (r : rs) =
if aa <= ba
then gather (r : a) (aa + or1 r) b ba rs
else gather a aa (r : b) (ba + or1 r) rs
gather a aa b ba [] = ((reverse a, aa), (b, ba))
or1 w = maybe 1 area $ M.lookup w params
-- Figure out which ways to split the space, by exhaustive search.
-- Complexity is quadratic in the number of windows.
findSplits :: Int -> Rectangle -> Tree -> Params -> (Double, [(Window, Rectangle)])
findSplits _ _ None _ = (0, [])
findSplits _ rect (Leaf w) params = (aspectBadness rect w params, [(w, rect)])
findSplits depth rect (Node (aArea, aTree) (bArea, bTree)) params =
if hBadness < vBadness then (hBadness, hList) else (vBadness, vList)
where
(hBadness, hList) = trySplit splitHorizontallyBy
(vBadness, vList) = trySplit splitVerticallyBy
trySplit splitBy =
(aBadness + bBadness, aList ++ bList)
where
(aBadness, aList) = findSplits (depth - 1) aRect aTree params
(bBadness, bList) = findSplits (depth - 1) bRect bTree params
(aRect, bRect) = splitBy ratio rect
ratio = aArea / (aArea + bArea)
-- Decide how much we like this rectangle.
aspectBadness :: Rectangle -> Window -> Params -> Double
aspectBadness rect win params =
(if a < 1 then tall else wide) * sqrt(w * h)
where
tall = if w < 700 then ((1 / a) * (700 / w)) else 1 / a
wide = if w < 700 then a else (a * w / 700)
a = (w / h) / fromRational (maybe 1.5 aspect $ M.lookup win params)
w = fromIntegral $ rect_width rect
h = fromIntegral $ rect_height rect
-- vim: sw=4:et
