AutoMaster.dpatch

Provides layout modifier AutoMaster. It separates screen in two parts -
master and slave. Size of slave area automatically changes depending on
number of slave windows.

XMonad/Layout/AutoMaster.hs

@@ -0,0 +1,123 @@
+{-# LANGUAGE FlexibleInstances, MultiParamTypeClasses, TypeSynonymInstances, FlexibleContexts #-}
+-----------------------------------------------------------------------------
+-- |
+-- Module      :  XMonad.Layout.AutoMaster
+-- Copyright   :  (c) 2009 Ilya Portnov
+-- License     :  BSD3-style (see LICENSE)
+--
+-- Maintainer  :  Ilya Portnov <portnov84@rambler.ru>
+-- Stability   :  unstable
+-- Portability :  unportable
+--
+-- Provides layout modifier AutoMaster. It separates screen in two parts - 
+-- master and slave. Size of slave area automatically changes depending on
+-- number of slave windows.
+--
+-----------------------------------------------------------------------------
+
+module XMonad.Layout.AutoMaster (
+                             -- * Usage
+                             -- $usage
+                             autoMaster
+                            ) where
+import Control.Monad
+
+import XMonad
+import qualified XMonad.StackSet as W
+import XMonad.Layout.LayoutModifier
+
+-- $usage
+-- This module defines layout modifier named autoMaster. It separates
+-- screen in two parts - master and slave. Master windows are arranged
+-- in one row, in slave area underlying layout is run. Size of slave area
+-- automatically increases when number of slave windows is increasing.
+--
+-- You can use this module by adding folowing in your @xmonad.hs@:
+--
+-- > import XMonad.Layout.AutoMaster
+--
+-- Then add layouts to your layoutHook:
+--
+-- > myLayoutHook = autoMaster 1 (1/100) Grid ||| ...
+--
+-- In this example, master area by default contains 1 window (you can
+-- change this number in runtime with usual IncMasterN message), changing
+-- slave area size with 1/100 on each Shrink/Expand message.
+
+-- | Data type for layout modifier
+data AutoMaster a = AutoMaster Int Float Float
+    deriving (Read,Show)
+
+instance LayoutModifier AutoMaster Window where
+    modifyLayout (AutoMaster k bias _) = autoLayout k bias 
+    pureMess = autoMess
+
+-- | Handle Shrink/Expand and IncMasterN messages
+autoMess :: AutoMaster a -> SomeMessage -> Maybe (AutoMaster a)
+autoMess (AutoMaster k bias delta) m = msum [fmap resize (fromMessage m),
+                                             fmap incmastern (fromMessage m)]
+    where incmastern (IncMasterN d) = AutoMaster (max 1 (k+d)) bias delta
+          resize Expand = AutoMaster k (min ( 0.4)  $ bias+delta) delta
+          resize Shrink = AutoMaster k (max (-0.4)  $ bias-delta) delta
+
+-- | Main layout function
+autoLayout :: (LayoutClass l Window) =>
+              Int ->
+              Float ->
+              W.Workspace WorkspaceId (l Window) Window
+              -> Rectangle
+              -> X ([(Window, Rectangle)], Maybe (l Window))
+autoLayout k bias wksp rect = do
+    let stack = W.stack wksp
+    let ws = W.integrate' stack
+    let n = length ws
+    if null ws then
+        runLayout wksp rect
+        else do
+          if (n<=k) then
+              return ((divideRow rect ws),Nothing)
+              else do
+              let master = take k ws
+              let filtStack = stack >>= W.filter (\w -> not (w `elem` master))
+              wrs <- runLayout (wksp {W.stack = filtStack}) (slaveRect rect n bias)
+              return ((divideRow (masterRect rect n bias) master) ++ (fst wrs),
+                      snd wrs)
+
+-- | Calculates height of master area, depending on number of windows.
+masterHeight :: Int -> Float -> Float
+masterHeight n bias = (calcHeight n) + bias
+    where calcHeight :: Int -> Float
+          calcHeight 1 = 1.0
+          calcHeight m = if (m<9) then (43/45) - (fromIntegral m)*(7/90) else (1/3)
+
+-- | Rectangle for master area
+masterRect :: Rectangle -> Int -> Float -> Rectangle
+masterRect (Rectangle sx sy sw sh) n bias = Rectangle sx sy sw h
+    where h = round $ (fromIntegral sh)*(masterHeight n bias)
+
+-- | Rectangle for slave area
+slaveRect :: Rectangle -> Int -> Float -> Rectangle
+slaveRect (Rectangle sx sy sw sh) n bias = Rectangle sx (sy+(fromIntegral mh)) sw h
+    where mh = round $ (fromIntegral sh)*(masterHeight n bias)
+          h  = round $ (fromIntegral sh)*(1-masterHeight n bias)
+
+-- | Divide rectangle between windows 
+divideRow :: Rectangle -> [a] -> [(a, Rectangle)]
+divideRow (Rectangle x y w h) ws = zip ws rects
+    where n = length ws
+          oneW = fromIntegral w `div` n
+          oneRect = Rectangle x y (fromIntegral oneW) h
+          rects = take n $ iterate (shiftR (fromIntegral oneW)) oneRect
+
+-- | Shift rectangle right 
+shiftR :: Position -> Rectangle -> Rectangle
+shiftR s (Rectangle x y w h) = Rectangle (x+s) y w h
+
+-- | User interface function
+autoMaster :: LayoutClass l a =>
+              Int ->      -- Number of master windows
+              Float ->    -- Step for which to increment/decrement master area size with Shrink/Expand
+              l a ->
+              ModifiedLayout AutoMaster l a
+autoMaster nmaster delta = ModifiedLayout (AutoMaster nmaster 0 delta)
+

xmonad-contrib.cabal

@@ -128,6 +128,7 @@ library
                         XMonad.Hooks.UrgencyHook
                         XMonad.Hooks.XPropManage
                         XMonad.Layout.Accordion
+                        XMonad.Layout.AutoMaster
                         XMonad.Layout.BoringWindows
                         XMonad.Layout.CenteredMaster
                         XMonad.Layout.Circle