{-# OPTIONS -fglasgow-exts #-}
-----------------------------------------------------------------------------
-- |
-- Module : XMonadContrib.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 XMonadContrib.MosaicAlt (
-- * Usage:
-- $usage
MosaicAlt(..)
, shrinkWindowAlt
, expandWindowAlt
, resetAlt
) where
import XMonad
import Operations
import Graphics.X11.Xlib
import qualified StackSet as W
import qualified Data.Map as M
import Data.List ( sortBy )
import Data.Ratio
import Graphics.X11.Types ( Window )
-- $usage
-- You can use this module with the following in your configuration file:
--
-- > import XMonadContrib.MosaicAlt
--
-- > defaultLayouts = ...
-- > , SomeLayout $ MosaicAlt M.empty
-- > ...
--
-- > keys = ...
-- > , ((modMask .|. shiftMask, xK_a), withFocused (sendMessage . expandWindowAlt))
-- > , ((modMask .|. shiftMask, xK_z), withFocused (sendMessage . shrinkWindowAlt))
-- > , ((modMask .|. controlMask, xK_space), sendMessage resetAlt)
-- > ...
-- %import XMonadContrib.MosaicAlt
-- %layout , SomeLayout $ MosaicAlt M.empty
data HandleWindowAlt =
ShrinkWindowAlt Window
| ExpandWindowAlt Window
| ResetAlt
deriving ( Typeable, Eq )
instance Message HandleWindowAlt
shrinkWindowAlt, expandWindowAlt :: Window -> HandleWindowAlt
shrinkWindowAlt = ShrinkWindowAlt
expandWindowAlt = ExpandWindowAlt
resetAlt :: HandleWindowAlt
resetAlt = ResetAlt
type Areas = M.Map Window Rational
data MosaicAlt a = MosaicAlt Areas deriving ( Show, Read )
instance Layout MosaicAlt Window where
description _ = "MosaicAlt"
doLayout (MosaicAlt areas) rect stack =
return (arrange rect stack areas', Just $ MosaicAlt areas')
where
areas' = ins (W.up stack) $ ins (W.down stack) $ ins [W.focus stack] areas
ins wins as = foldl M.union as $ map (`M.singleton` 1) wins
handleMessage (MosaicAlt areas) msg = return $ case fromMessage msg of
Just (ShrinkWindowAlt w) -> Just $ MosaicAlt $ alter areas w (4 % 5)
Just (ExpandWindowAlt w) -> Just $ MosaicAlt $ alter areas w (6 % 5)
Just ResetAlt -> Just $ MosaicAlt M.empty
_ -> Nothing
-- Layout algorithm entry point.
arrange :: Rectangle -> W.Stack Window -> Areas -> [(Window, Rectangle)]
arrange rect stack areas = tree rect (sortBy areaCompare winList) totalArea areas
where
winList = reverse (W.up stack) ++ W.focus stack : W.down stack
totalArea = areaSum areas winList
areaCompare a b = or1 b `compare` or1 a
or1 w = maybe 1 id $ M.lookup w areas
-- Selects a horizontal or vertical split to get the best aspect ratio.
-- FIXME: Give the user more dynamic control.
splitBest :: Rational -> Rectangle -> (Rectangle, Rectangle)
splitBest ratio rect =
if (w % h) < cutoff then splitVerticallyBy ratio rect
else splitHorizontallyBy ratio rect
where
-- Prefer wide windows to tall ones, mainly because it makes xterms more usable.
cutoff = if w > 1000 then 1.25
else if w < 500 then 2.25
else 2.25 - (w - 500) % 500
w = rect_width rect
h = rect_height rect
-- Recursively group windows into a binary tree. Aim to balance the tree
-- according to the total requested area in each branch.
tree :: Rectangle -> [Window] -> Rational -> Areas -> [(Window, Rectangle)]
tree rect winList totalArea areas = case winList of
[] -> []
[x] -> [(x, rect)]
_ -> tree aRect aWins aArea areas ++ tree bRect bWins bArea areas
where
(aRect, bRect) = splitBest (aArea / (aArea + bArea)) rect
((aWins, aArea), (bWins, bArea)) = areaSplit areas winList totalArea
-- Sum the requested areas of a bunch of windows.
areaSum :: Areas -> [Window] -> Rational
areaSum areas = sum . map (maybe 1 id . flip M.lookup areas)
-- Split a list of windows in half by area.
areaSplit :: Areas -> [Window] -> Rational -> (([Window], Rational), ([Window], Rational))
areaSplit areas wins totalArea = ((reverse aWins, aArea), (bWins, bArea))
where
((aWins, aArea), (bWins, bArea)) = gather [] wins 0
gather a b t = if t >= (totalArea / 2) then ((a, t), (b, totalArea - t))
else gather (head b : a) (tail b) (t + or1 (head b))
or1 w = maybe 1 id $ M.lookup w areas
-- Change requested area for a window.
alter :: Areas -> Window -> Rational -> Areas
alter areas win delta = case M.lookup win areas of
Just v -> M.insert win (v * delta) areas
Nothing -> M.insert win delta areas
-- vim: sw=4:et
