{-# LANGUAGE FlexibleContexts, FlexibleInstances, MultiParamTypeClasses, UndecidableInstances, PatternGuards, DeriveDataTypeable #-}
-----------------------------------------------------------------------------
-- |
-- Module : XMonad.Layout.LayoutBuilder
-- Copyright : (c) 2009 Anders Engstrom <ankaan@gmail.com>
-- License : BSD3-style (see LICENSE)
--
-- Maintainer : Anders Engstrom <ankaan@gmail.com>
-- Stability : unstable
-- Portability : unportable
--
-- A layout combinator that sends a specified number of windows to one rectangle
-- and the rest to another.
--
-----------------------------------------------------------------------------
module XMonad.Layout.LayoutBuilder (
-- * Usage
-- $usage
layoutN,
layoutR,
layoutAll,
IncLayoutN (..),
SubMeasure (..),
SubBox (..),
absBox,
relBox,
LayoutN,
) where
import XMonad
import qualified XMonad.StackSet as W
import Data.Maybe (isJust)
-- $usage
-- You can use this module with the following in your @~\/.xmonad\/xmonad.hs@:
--
-- > import XMonad.Layout.LayoutBuilder
--
-- Then edit your @layoutHook@ by adding something like:
--
-- > myLayout = ( (layoutN 1 (relBox 0 0 0.5 1) (Just $ relBox 0 0 1 1) $ simpleTabbed)
-- > $ (layoutAll (relBox 0.5 0 1 1) $ simpleTabbed)
-- > ) |||
-- > ( (layoutN 1 (relBox (1/3) 0 (1/2) 1) (Just $ relBox 0 0 1 1) $ Tall 0 0.01 0.5)
-- > $ (layoutR 0.1 0.5 (relBox (2/3) 0 1 1) Nothing $ Tall 0 0.01 0.5)
-- > $ (layoutAll (relBox 0 0 (1/3) 1) $ Tall 0 0.01 0.5)
-- > ) |||
-- > ( (layoutN 1 (absBox (-512-200) 0 512 0) (Just $ relBox 0 0 1 1) $ simpleTabbed)
-- > $ (layoutN 1 (absBox (-200) 0 0 0) Nothing $ simpleTabbed)
-- > $ (layoutAll (absBox 0 0 (-512-200) 0) $ simpleTabbed)
-- > ) ||| Full ||| etc...
-- > main = xmonad def { layoutHook = myLayout }
--
-- This will produce a layout similar to DragPane, but with the possibility to have multiple windows in the left half
-- and tabs that show the available windows. It will also produce a layout similar to ThreeColMid and a special layout
-- created for use with a 80 columns wide Emacs window, its sidebar and a tabbed area for all other windows.
--
-- This module can be used to create many different custom layouts, but there are limitations. The primary limitation
-- can be observed in the second and third example when there are only two columns with windows in them. The leftmost
-- area is left blank. These blank areas can be avoided by placing the rectangles appropriately.
--
-- These examples require "XMonad.Layout.Tabbed".
--
-- For more detailed instructions on editing the layoutHook see:
--
-- "XMonad.Doc.Extending#Editing_the_layout_hook"
--
-- You may wish to add the following keybindings:
--
-- > , ((modm .|. shiftMask, xK_h ), sendMessage $ IncLayoutN (-1))
-- > , ((modm .|. shiftMask, xK_l ), sendMessage $ IncLayoutN 1)
--
-- For detailed instruction on editing the key binding see:
--
-- "XMonad.Doc.Extending#Editing_key_bindings".
type WindowNum = Either Int (Rational,Rational)
-- | Use one layout in the specified area for a number of windows and possibly let another layout handle the rest.
data LayoutN l1 l2 a =
LayoutN (Maybe a) (Maybe a) WindowNum SubBox (Maybe SubBox) (l1 a) (Maybe (l2 a))
deriving (Show,Read)
-- | Use the specified layout in the described area for N windows and send the rest of the windows to the next layout in the chain.
-- It is possible to supply an alternative area that will then be used instead, if there are no windows to send to the next layout.
layoutN :: (Read a, Eq a, LayoutClass l1 a, LayoutClass l2 a, LayoutClass l3 a) =>
Int -- ^ The number of windows to handle
-> SubBox -- ^ The box to place the windows in
-> Maybe SubBox -- ^ Possibly an alternative box that is used when this layout handles all windows that are left
-> l1 a -- ^ The layout to use in the specified area
-> LayoutN l2 l3 a -- ^ Where to send the remaining windows
-> LayoutN l1 (LayoutN l2 l3) a -- ^ The resulting layout
layoutN num box mbox sub next = LayoutN Nothing Nothing (Left num) box mbox sub (Just next)
-- | As layoutN, but the number of windows is given relative to the total number of windows remaining to be handled. The first
-- argument is how much to change the ratio when using IncLayoutN, and the second is the initial ratio.
layoutR :: (Read a, Eq a, LayoutClass l1 a, LayoutClass l2 a, LayoutClass l3 a) =>
Rational -- ^ How much to change the ratio with each IncLayoutN
-> Rational -- ^ The ratio of the remaining windows to handle
-> SubBox -- ^ The box to place the windows in
-> Maybe SubBox -- ^ Possibly an alternative box that is used when this layout handles all windows that are left
-> l1 a -- ^ The layout to use in the specified area
-> LayoutN l2 l3 a -- ^ Where to send the remaining windows
-> LayoutN l1 (LayoutN l2 l3) a -- ^ The resulting layout
layoutR numdiff num box mbox sub next = LayoutN Nothing Nothing (Right (numdiff,num)) box mbox sub (Just next)
-- | Use the specified layout in the described area for all remaining windows.
layoutAll :: (Read a, Eq a, LayoutClass l1 a) =>
SubBox -- ^ The box to place the windows in
-> l1 a -- ^ The layout to use in the specified area
-> LayoutN l1 Full a -- ^ The resulting layout
layoutAll box sub = LayoutN Nothing Nothing (Right (0,1)) box Nothing sub Nothing
-- | Change the number of windows handled by the focused layout.
data IncLayoutN = IncLayoutN Int deriving Typeable
instance Message IncLayoutN
-- | The absolute or relative measures used to describe the area a layout should be placed in. For negative absolute values
-- the total remaining space will be added. For sizes, the remaining space will also be added for zeroes. Relative values
-- are applied on the remaining space after the top-left corner of the box have been removed.
data SubMeasure = Abs Int | Rel Rational deriving (Show,Read)
-- | A box to place a layout in. The stored values are xpos, ypos, width and height.
data SubBox = SubBox SubMeasure SubMeasure SubMeasure SubMeasure deriving (Show,Read)
-- | Create a box with only absolute measurements. If the values are negative, the total remaining space will be added. For
-- sizes it will also be added for zeroes.
absBox :: Int -- ^ Absolute X-Position
-> Int -- ^ Absolute Y-Position
-> Int -- ^ Absolute width
-> Int -- ^ Absolute height
-> SubBox -- ^ The resulting 'SubBox' describing the area
absBox x y w h = SubBox (Abs x) (Abs y) (Abs w) (Abs h)
-- | Create a box with only relative measurements.
relBox :: Rational -- ^ Relative X-Position with respect to the surrounding area
-> Rational -- ^ Relative Y-Position with respect to the surrounding area
-> Rational -- ^ Relative width with respect to the remaining width
-> Rational -- ^ Relative height with respect to the remaining height
-> SubBox -- ^ The resulting 'SubBox' describing the area
relBox x y w h = SubBox (Rel x) (Rel y) (Rel w) (Rel h)
instance (LayoutClass l1 a, LayoutClass l2 a, Read a, Show a, Eq a, Typeable a) =>
LayoutClass (LayoutN l1 l2) a where
-- | Update window locations.
runLayout (W.Workspace _ (LayoutN subf nextf num box mbox sub next) s) rect
= do let (subs,nexts,subf',nextf') = splitStack s num subf nextf
selBox = if isJust nextf'
then box
else maybe box id mbox
(sublist,sub') <- handle sub subs $ calcArea selBox rect
(nextlist,next') <- case next of Nothing -> return ([],Nothing)
Just n -> do (res,l) <- handle n nexts rect
return (res,Just l)
return (sublist++nextlist, Just $ LayoutN subf' nextf' num box mbox sub' next' )
where
handle l s' r = do (res,ml) <- runLayout (W.Workspace "" l s') r
l' <- return $ maybe l id ml
return (res,l')
-- | Propagate messages.
handleMessage l m
| Just (IncLayoutN _) <- fromMessage m = windowNum l m
| Just (IncMasterN _) <- fromMessage m = sendFocus l m
| Just (Shrink) <- fromMessage m = sendFocus l m
| Just (Expand) <- fromMessage m = sendFocus l m
| otherwise = sendBoth l m
-- | Descriptive name for layout.
description (LayoutN _ _ _ _ _ sub Nothing) = "layoutAll "++ description sub
description (LayoutN _ _ (Left _) _ _ sub (Just next)) = "layoutN "++ description sub ++" "++ description next
description (LayoutN _ _ (Right _) _ _ sub (Just next)) = "layoutR "++ description sub ++" "++ description next
windowNum :: (LayoutClass l1 a, LayoutClass l2 a, Read a, Show a, Eq a, Typeable a) => LayoutN l1 l2 a -> SomeMessage -> X (Maybe (LayoutN l1 l2 a))
windowNum l@(LayoutN subf nextf num box mbox subl nextl) m | (Just (IncLayoutN n)) <- fromMessage m =
do foc <- isFocus subf
if foc then do let newnum = case num of
(Left oldnum) -> Left $ max 1 $ oldnum + n
(Right (diff,oldnum)) -> Right (diff, min 1 $ max 0 $ oldnum + (fromIntegral n)*diff)
return $ Just $ LayoutN subf nextf newnum box mbox subl nextl
else sendNext l m
windowNum l m = sendNext l m
sendSub :: (LayoutClass l1 a, LayoutClass l2 a, Read a, Show a, Eq a, Typeable a) => LayoutN l1 l2 a -> SomeMessage -> X (Maybe (LayoutN l1 l2 a))
sendSub (LayoutN subf nextf num box mbox sub next) m =
do sub' <- handleMessage sub m
return $ if isJust sub'
then Just $ LayoutN subf nextf num box mbox (maybe sub id sub') next
else Nothing
sendBoth :: (LayoutClass l1 a, LayoutClass l2 a, Read a, Show a, Eq a, Typeable a) => LayoutN l1 l2 a -> SomeMessage -> X (Maybe (LayoutN l1 l2 a))
sendBoth l@(LayoutN _ _ _ _ _ _ Nothing) m = sendSub l m
sendBoth (LayoutN subf nextf num box mbox sub (Just next)) m =
do sub' <- handleMessage sub m
next' <- handleMessage next m
return $ if isJust sub' || isJust next'
then Just $ LayoutN subf nextf num box mbox (maybe sub id sub') (Just $ maybe next id next')
else Nothing
sendNext :: (LayoutClass l1 a, LayoutClass l2 a, Read a, Show a, Eq a, Typeable a) => LayoutN l1 l2 a -> SomeMessage -> X (Maybe (LayoutN l1 l2 a))
sendNext (LayoutN _ _ _ _ _ _ Nothing) _ = return Nothing
sendNext (LayoutN subf nextf num box mbox sub (Just next)) m =
do next' <- handleMessage next m
return $ if isJust next'
then Just $ LayoutN subf nextf num box mbox sub next'
else Nothing
sendFocus :: (LayoutClass l1 a, LayoutClass l2 a, Read a, Show a, Eq a, Typeable a) => LayoutN l1 l2 a -> SomeMessage -> X (Maybe (LayoutN l1 l2 a))
sendFocus l@(LayoutN subf _ _ _ _ _ _) m = do foc <- isFocus subf
if foc then sendSub l m
else sendNext l m
isFocus :: (Show a) => Maybe a -> X Bool
isFocus Nothing = return False
isFocus (Just w) = do ms <- (W.stack . W.workspace . W.current) `fmap` gets windowset
return $ maybe False (\s -> show w == (show $ W.focus s)) ms
calcNum :: Int -> WindowNum -> Int
calcNum tot num = max 1 $ case num of Left i -> i
Right (_,r) -> ceiling $ r * fromIntegral tot
splitStack :: Eq a => Maybe (W.Stack a) -> WindowNum -> Maybe a -> Maybe a -> (Maybe (W.Stack a),Maybe (W.Stack a),Maybe a,Maybe a)
splitStack Nothing _ _ _ = (Nothing,Nothing,Nothing,Nothing)
splitStack (Just s) num subf nextf = ( differentiate' subf' subl
, differentiate' nextf' nextl
, subf'
, nextf'
)
where
ws = W.integrate s
n = calcNum (length ws) num
subl = take n ws
nextl = drop n ws
subf' = foc subl subf
nextf' = foc nextl nextf
foc [] _ = Nothing
foc l f = if W.focus s `elem` l
then Just $ W.focus s
else if maybe False (`elem` l) f
then f
else Just $ head l
calcArea :: SubBox -> Rectangle -> Rectangle
calcArea (SubBox xpos ypos width height) rect = Rectangle (rect_x rect + fromIntegral xpos') (rect_y rect + fromIntegral ypos') width' height'
where
xpos' = calc False xpos $ rect_width rect
ypos' = calc False ypos $ rect_height rect
width' = calc True width $ rect_width rect - xpos'
height' = calc True height $ rect_height rect - ypos'
calc zneg val tot = fromIntegral $ min (fromIntegral tot) $ max 0 $
case val of Rel v -> floor $ v * fromIntegral tot
Abs v -> if v<0 || (zneg && v==0)
then (fromIntegral tot)+v
else v
differentiate' :: Eq q => Maybe q -> [q] -> Maybe (W.Stack q)
differentiate' _ [] = Nothing
differentiate' Nothing w = W.differentiate w
differentiate' (Just f) w
| f `elem` w = Just $ W.Stack { W.focus = f
, W.up = reverse $ takeWhile (/=f) w
, W.down = tail $ dropWhile (/=f) w
}
| otherwise = W.differentiate w
