content: {-# LANGUAGE FlexibleInstances, MultiParamTypeClasses #-}
  -----------------------------------------------------------------------------
  -- |
  -- Module      :  XMonad.Layout.DwmStyle
  -- Copyright   :  (c) 2007 Andrea Rossato
  -- License     :  BSD-style (see xmonad/LICENSE)
  --
  -- Maintainer  :  andrea.rossato@unibz.it
  -- Stability   :  unstable
  -- Portability :  unportable
  --
  -- A layout modifier for decorating windows in a dwm like style.
  -----------------------------------------------------------------------------
  
  module XMonad.Layout.DwmStyle
      ( -- * Usage:
        -- $usage
        dwmStyle
      , Theme (..)
      , def
      , defaultTheme
      , DwmStyle (..)
      , shrinkText, CustomShrink(CustomShrink)
      , Shrinker(..)
      ) where
  
  import XMonad
  import XMonad.StackSet ( Stack (..) )
  import XMonad.Layout.Decoration
  
  -- $usage
  -- You can use this module with the following in your
  -- @~\/.xmonad\/xmonad.hs@:
  --
  -- > import XMonad.Layout.DwmStyle
  --
  -- Then edit your @layoutHook@ by adding the DwmStyle decoration to
  -- your layout:
  --
  -- > myL = dwmStyle shrinkText def (layoutHook def)
  -- > main = xmonad def { layoutHook = myL }
  --
  -- For more detailed instructions on editing the layoutHook see:
  --
  -- "XMonad.Doc.Extending#Editing_the_layout_hook"
  --
  -- You can also edit the default configuration options.
  --
  -- > myDWConfig = def { inactiveBorderColor = "red"
  -- >                  , inactiveTextColor   = "red"}
  --
  -- and
  --
  -- > myL = dwmStyle shrinkText myDWConfig (layoutHook def)
  --
  -- A complete xmonad.hs file for this would therefore be:
  --
  -- > import XMonad
  -- > import XMonad.Layout.DwmStyle
  -- >
  -- > main = xmonad def {
  -- >     layoutHook = dwmStyle shrinkText def (layoutHook def)
  -- >     }
  --
  
  
  -- | Add simple old dwm-style decorations to windows of a layout.
  dwmStyle :: (Eq a, Shrinker s) => s -> Theme
           -> l a -> ModifiedLayout (Decoration DwmStyle s) l a
  dwmStyle s c = decoration s c Dwm
  
  data DwmStyle a = Dwm deriving (Show, Read)
  
  instance Eq a => DecorationStyle DwmStyle a where
      describeDeco _ = "DwmStyle"
      shrink  _ _  r = r
      pureDecoration _ wh ht _ s@(Stack fw _ _) _ (w,Rectangle x y wid _) =
          if w == fw || not (isInStack s w) then Nothing else Just $ Rectangle (fi nx) y nwh (fi ht)
              where nwh = min wid $ fi wh
                    nx  = fi x + wid - nwh
  