content: {-# LANGUAGE TypeSynonymInstances, MultiParamTypeClasses, DeriveDataTypeable #-}
  {-# LANGUAGE PatternGuards, FlexibleContexts, FlexibleInstances #-}
  -----------------------------------------------------------------------------
  -- |
  -- Module      :  XMonad.Layout.BoringWindows
  -- Copyright   :  (c) 2008  David Roundy <droundy@darcs.net>
  -- License     :  BSD3-style (see LICENSE)
  --
  -- Maintainer  :  Adam Vogt <vogt.adam@gmail.com>
  -- Stability   :  unstable
  -- Portability :  unportable
  --
  -- BoringWindows is an extension to allow windows to be marked boring
  --
  -----------------------------------------------------------------------------
  
  module XMonad.Layout.BoringWindows (
                                     -- * Usage
                                     -- $usage
                                     boringWindows, boringAuto,
                                     markBoring, clearBoring,
                                     focusUp, focusDown, focusMaster,
  
                                     UpdateBoring(UpdateBoring),
                                     BoringMessage(Replace,Merge),
                                     BoringWindows()
  
                                     -- * Tips
                                     -- ** variant of 'Full'
                                     -- $simplest
                                    ) where
  
  import XMonad.Layout.LayoutModifier(ModifiedLayout(..),
                                      LayoutModifier(handleMessOrMaybeModifyIt, redoLayout))
  import XMonad(Typeable, LayoutClass, Message, X, fromMessage,
                sendMessage, windows, withFocused, Window)
  import Control.Applicative((<$>))
  import Data.List((\\), union)
  import Data.Maybe(fromMaybe, listToMaybe, maybeToList)
  import qualified Data.Map as M
  import qualified XMonad.StackSet as W
  
  -- $usage
  -- You can use this module with the following in your
  -- @~\/.xmonad\/xmonad.hs@:
  --
  -- > import XMonad.Layout.BoringWindows
  --
  -- Then edit your @layoutHook@ by adding the layout modifier:
  --
  -- > myLayout = boringWindows (Full ||| etc..)
  -- > main = xmonad def { layoutHook = myLayout }
  --
  -- Then to your keybindings, add:
  --
  -- > , ((modm, xK_j), focusUp)
  -- > , ((modm, xK_k), focusDown)
  -- > , ((modm, xK_m), focusMaster)
  --
  -- For more detailed instructions on editing the layoutHook see:
  --
  -- "XMonad.Doc.Extending#Editing_the_layout_hook"
  
  
  data BoringMessage = FocusUp | FocusDown | FocusMaster | IsBoring Window | ClearBoring
                       | Replace String [Window]
                       | Merge String [Window]
                       deriving ( Read, Show, Typeable )
  
  instance Message BoringMessage
  
  -- | UpdateBoring is sent before attempting to view another boring window, so
  -- that layouts have a chance to mark boring windows.
  data UpdateBoring = UpdateBoring
      deriving (Typeable)
  instance Message UpdateBoring
  
  markBoring, clearBoring, focusUp, focusDown, focusMaster :: X ()
  markBoring = withFocused (sendMessage . IsBoring)
  clearBoring = sendMessage ClearBoring
  focusUp = sendMessage UpdateBoring >> sendMessage FocusUp
  focusDown = sendMessage UpdateBoring >> sendMessage FocusDown
  focusMaster = sendMessage UpdateBoring >> sendMessage FocusMaster
  
  data BoringWindows a = BoringWindows
      { namedBoring :: M.Map String [a] -- ^ store borings with a specific source
      , chosenBoring :: [a]             -- ^ user-chosen borings
      , hiddenBoring :: Maybe [a]       -- ^ maybe mark hidden windows
      } deriving (Show,Read,Typeable)
  
  boringWindows :: (LayoutClass l a, Eq a) => l a -> ModifiedLayout BoringWindows l a
  boringWindows = ModifiedLayout (BoringWindows M.empty [] Nothing)
  
  -- | Mark windows that are not given rectangles as boring
  boringAuto :: (LayoutClass l a, Eq a) => l a -> ModifiedLayout BoringWindows l a
  boringAuto = ModifiedLayout (BoringWindows M.empty [] (Just []))
  
  instance LayoutModifier BoringWindows Window where
      redoLayout (b@BoringWindows { hiddenBoring = bs }) _r mst arrs = do
          let bs' = W.integrate' mst \\ map fst arrs
          return (arrs, Just $ b { hiddenBoring = const bs' <$> bs } )
  
      handleMessOrMaybeModifyIt bst@(BoringWindows nbs cbs lbs) m
          | Just (Replace k ws) <- fromMessage m
          , maybe True (ws/=) (M.lookup k nbs) =
              let nnb = if null ws then M.delete k nbs
                            else M.insert k ws nbs
              in rjl bst { namedBoring = nnb }
          | Just (Merge k ws) <- fromMessage m
          , maybe True (not . null . (ws \\)) (M.lookup k nbs) =
              rjl bst { namedBoring = M.insertWith union k ws nbs }
          | Just (IsBoring w) <- fromMessage m , w `notElem` cbs =
              rjl bst { chosenBoring = w:cbs }
          | Just ClearBoring <- fromMessage m, not (null cbs) =
              rjl bst { namedBoring = M.empty, chosenBoring = []}
          | Just FocusUp <- fromMessage m =
                              do windows $ W.modify' $ skipBoring W.focusUp'
                                 return Nothing
          | Just FocusDown <- fromMessage m =
                              do windows $ W.modify' $ skipBoring W.focusDown'
                                 return Nothing
          | Just FocusMaster <- fromMessage m =
                              do windows $ W.modify'
                                              $ skipBoring W.focusDown' -- wiggle focus to make sure
                                              . skipBoring W.focusUp'   -- no boring window gets the focus
                                              . focusMaster'
                                 return Nothing
          where skipBoring f st = fromMaybe st $ listToMaybe
                                  $ filter ((`notElem` W.focus st:bs) . W.focus)
                                  $ take (length $ W.integrate st)
                                  $ iterate f st
                bs = concat $ cbs:maybeToList lbs ++ M.elems nbs
                rjl = return . Just . Left
      handleMessOrMaybeModifyIt _ _ = return Nothing
  
  -- | Variant of 'focusMaster' that works on a
  -- 'Stack' rather than an entire 'StackSet'.
  focusMaster' :: W.Stack a -> W.Stack a
  focusMaster' c@(W.Stack _ [] _) = c
  focusMaster' (W.Stack t ls rs) = W.Stack x [] (xs ++ t : rs) where (x:xs) = reverse ls
  
  {- $simplest
  
  An alternative to 'Full' is "XMonad.Layout.Simplest".  Less windows are
  ignored by 'focusUp' and 'focusDown'. This may be helpful when you want windows
  to be uninteresting by some other layout modifier (ex.
  "XMonad.Layout.Minimize")
  
  -}
  