Add FixedColumn, a layout like Tall but based on the resize hints of windows

XMonad/Layout/FixedColumn.hs

@@ -0,0 +1,91 @@
+{-# LANGUAGE FlexibleInstances, MultiParamTypeClasses, TypeSynonymInstances #-}
+-----------------------------------------------------------------------------
+-- |
+-- Module      :  XMonad.Layout.FixedColumn
+-- Copyright   :  (c) 2008 Justin Bogner <mail@justinbogner.com>
+-- License     :  BSD3-style (as xmonad)
+--
+-- Maintainer  :  Justin Bogner <mail@justinbogner.com>
+-- Stability   :  unstable
+-- Portability :  unportable
+--
+-- A layout much like Tall, but using a multiple of a window's minimum
+-- resize amount instead of a percentage of screen to decide where to
+-- split. This is useful when you usually leave a text editor or
+-- terminal in the master pane and like it to be 80 columns wide.
+--
+-----------------------------------------------------------------------------
+
+module XMonad.Layout.FixedColumn (
+    -- * Usage
+    -- $usage
+        FixedColumn(..)
+) where
+
+import Control.Monad (msum)
+import Data.Maybe (fromMaybe)
+import Graphics.X11.Xlib (Window, rect_width)
+import Graphics.X11.Xlib.Extras ( getWMNormalHints
+                                , getWindowAttributes
+                                , sh_base_size
+                                , sh_resize_inc
+                                , wa_border_width)
+
+import XMonad.Core (X, LayoutClass(..), fromMessage, io, withDisplay)
+import XMonad.Layout (Resize(..), IncMasterN(..), tile)
+import XMonad.StackSet as W
+
+-- $usage
+-- You can use this module with the following in your @~\/.xmonad\/xmonad.hs@:
+--
+-- > import XMonad.Layout.FixedColumn
+--
+-- Then edit your @layoutHook@ by adding the FixedColumn layout:
+--
+-- > myLayouts = FixedColumn 20 80 10 ||| Full ||| etc..
+-- > main = xmonad defaultConfig { layoutHook = myLayouts }
+--
+-- For more detailed instructions on editing the layoutHook see:
+--
+-- "XMonad.Doc.Extending#Editing_the_layout_hook"
+
+-- | A tiling mode based on preserving a nice fixed width
+--   window. Supports 'Shrink', 'Expand' and 'IncMasterN'.
+data FixedColumn a = FixedColumn !Int -- Number of windows in the master pane
+                                 !Int -- Number to increment by when resizing
+                                 !Int -- Default width of master pane
+                                 !Int -- Column width for normal windows
+                        deriving (Read, Show)
+
+instance LayoutClass FixedColumn Window where
+    doLayout (FixedColumn nmaster _ ncol fallback) r s = do
+            fws <- mapM (widthCols fallback ncol) ws
+            let frac = maximum (take nmaster fws) // rect_width r
+                rs   = tile frac r nmaster (length ws)
+            return $ (zip ws rs, Nothing)
+        where ws     = W.integrate s
+              x // y = fromIntegral x / fromIntegral y
+
+    pureMessage (FixedColumn nmaster delta ncol fallback) m =
+            msum [fmap resize     (fromMessage m)
+                 ,fmap incmastern (fromMessage m)]
+        where resize Shrink
+                  = FixedColumn nmaster delta (max 0 $ ncol - delta) fallback
+              resize Expand
+                  = FixedColumn nmaster delta (ncol + delta) fallback
+              incmastern (IncMasterN d)
+                  = FixedColumn (max 0 (nmaster+d)) delta ncol fallback
+
+    description _ = "FixedColumn"
+
+-- | Determine the width of @w@ given that we would like it to be @n@
+--   columns wide, using @inc@ as a resize increment for windows that
+--   don't have one
+widthCols :: Int -> Int -> Window -> X Int
+widthCols inc n w = withDisplay $ \d -> io $ do
+    sh <- getWMNormalHints d w
+    bw <- fmap (fromIntegral . wa_border_width) $ getWindowAttributes d w
+    let widthHint f = f sh >>= return . fromIntegral . fst
+        oneCol      = fromMaybe inc $ widthHint sh_resize_inc
+        base        = fromMaybe 0 $ widthHint sh_base_size
+    return $ 2 * bw + base + n * oneCol

xmonad-contrib.cabal

@@ -129,6 +129,7 @@ library
                         XMonad.Layout.Dishes
                         XMonad.Layout.DragPane
                         XMonad.Layout.DwmStyle
+                        XMonad.Layout.FixedColumn
                         XMonad.Layout.Gaps
                         XMonad.Layout.Grid
                         XMonad.Layout.HintedGrid