Column_layout.dpatch

Ignore-this: ea5ebf0d6e8ac5c044d9291b3c55479d
This module defines layot named Column. It places all windows in one
column. Windows heights are calculated from equation: H1/H2

darcs-hash:20090605184515-94bf2-6842ff495fc3bcf3850291a3fc7f63a4d2c498d9.gz

1 files changed, 71 insertions, 0 deletions

diff --git a/XMonad/Layout/Column.hs b/XMonad/Layout/Column.hs
new file mode 100644
index 0000000..279525e
--- /dev/null
+++ b/XMonad/Layout/Column.hs
@@ -0,0 +1,71 @@
+{-# LANGUAGE FlexibleInstances, MultiParamTypeClasses, TypeSynonymInstances #-}
+-----------------------------------------------------------------------------
+-- |
+-- Module      :  XMonad.Layout.Column
+-- Copyright   :  (c) 2009 Ilya Portnov
+-- License     :  BSD3-style (see LICENSE)
+--
+-- Maintainer  :  Ilya Portnov <portnov84@rambler.ru>
+-- Stability   :  unstable
+-- Portability :  unportable
+--
+-- Provides Column layout that places all windows in one column. Windows
+-- heights are calculated from equation: H1/H2 = H2/H3 = ... = q, where q is
+-- given. With Shrink/Expand messages you can change the q value.
+--
+-----------------------------------------------------------------------------
+
+module XMonad.Layout.Column (
+                             -- * Usage
+                             -- $usage
+                             Column (..)
+                            ) where
+import XMonad
+import qualified XMonad.StackSet as W
+
+-- $usage
+-- This module defines layot named Column. It places all windows in one
+-- column. Windows heights are calculated from equation: H1/H2 = H2/H3 = ... =
+-- q, where `q' is given (thus, windows heights are members of geometric
+-- progression). With Shrink/Expand messages one can change the `q' value.
+--
+-- You can use this module by adding folowing in your @xmonad.hs@:
+--
+-- > import XMonad.Layout.Column
+--
+-- Then add layouts to your layoutHook:
+--
+-- > myLayoutHook = Column 1.6 ||| ...
+--
+-- In this example, each next window will have height 1.6 times less then
+-- previous window.
+
+data Column a = Column Float deriving (Read,Show)
+
+instance LayoutClass Column a where
+    pureLayout = columnLayout
+    pureMessage = columnMessage
+
+columnMessage :: Column a -> SomeMessage -> Maybe (Column a)
+columnMessage (Column q) m = fmap resize (fromMessage m)
+    where resize Shrink = Column (q-0.1)
+          resize Expand = Column (q+0.1)
+
+columnLayout :: Column a -> Rectangle -> W.Stack a -> [(a,Rectangle)]
+columnLayout (Column q) rect stack = zip ws rects
+    where ws = W.integrate stack
+          n = length ws
+          heights = map (xn n rect q) [1..n]
+          ys = [fromIntegral $ sum $ take k heights | k <- [0..n-1]]
+          rects = map (mkRect rect) $ zip heights ys
+
+mkRect :: Rectangle -> (Dimension,Position) -> Rectangle
+mkRect (Rectangle xs ys ws _) (h,y) = Rectangle xs (ys+fromIntegral y) ws h
+        
+xn :: Int -> Rectangle -> Float -> Int -> Dimension
+xn n (Rectangle _ _ _ h) q k = if q==1 then 
+                                  h `div` (fromIntegral n)
+                               else 
+                                  round ((fromIntegral h)*q^(n-k)*(1-q)/(1-q^n))
+
+