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Diffstat (limited to 'Layouts.hs')
| -rw-r--r-- | Layouts.hs | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/Layouts.hs b/Layouts.hs new file mode 100644 index 0000000..5605917 --- /dev/null +++ b/Layouts.hs @@ -0,0 +1,166 @@ +{-# OPTIONS_GHC -fglasgow-exts #-} -- For deriving Data/Typeable +{-# LANGUAGE FlexibleInstances, MultiParamTypeClasses, PatternGuards, TypeSynonymInstances #-} + +-- -------------------------------------------------------------------------- +-- | +-- Module : Layouts.hs +-- Copyright : (c) Spencer Janssen 2007 +-- License : BSD3-style (see LICENSE) +-- +-- Maintainer : sjanssen@cse.unl.edu +-- Stability : unstable +-- Portability : not portable, Typeable deriving, mtl, posix +-- +-- The collection of core layouts. +-- +----------------------------------------------------------------------------- + +module Layouts (ChangeLayout(..), Choose, (|||), Resize(..), IncMasterN(..), + Full(..), Tall(..), Mirror(..), splitVertically, + splitHorizontally, splitHorizontallyBy, splitVerticallyBy) where + +import XMonad + +import Graphics.X11 (Rectangle(..)) +import qualified StackSet as W +import Control.Arrow ((***), second) +import Control.Monad +import Data.Maybe (fromMaybe) + + +------------------------------------------------------------------------ +-- LayoutClass selection manager + +-- | A layout that allows users to switch between various layout options. + +-- | Messages to change the current layout. +data ChangeLayout = FirstLayout | NextLayout deriving (Eq, Show, Typeable) + +instance Message ChangeLayout + +-- | The layout choice combinator +(|||) :: (LayoutClass l a, LayoutClass r a) => l a -> r a -> Choose l r a +(|||) = flip SLeft +infixr 5 ||| + +data Choose l r a = SLeft (r a) (l a) + | SRight (l a) (r a) deriving (Read, Show) + +data NextNoWrap = NextNoWrap deriving (Eq, Show, Typeable) +instance Message NextNoWrap + +-- This has lots of pseudo duplicated code, we must find a better way +instance (LayoutClass l a, LayoutClass r a) => LayoutClass (Choose l r) a where + doLayout (SLeft r l) = (fmap (second . fmap $ SLeft r) .) . doLayout l + doLayout (SRight l r) = (fmap (second . fmap $ SRight l) .) . doLayout r + + description (SLeft _ l) = description l + description (SRight _ r) = description r + + handleMessage lr m | Just FirstLayout <- fromMessage m = case lr of + SLeft {} -> return Nothing + SRight l r -> fmap (Just . flip SLeft l . fromMaybe r) $ handleMessage r m + + handleMessage lr m | Just NextLayout <- fromMessage m = do + mlr <- handleMessage lr $ SomeMessage NextNoWrap + maybe (handleMessage lr $ SomeMessage FirstLayout) (return . Just) mlr + + handleMessage (SLeft r l) m | Just NextNoWrap <- fromMessage m = do + handleMessage l (SomeMessage Hide) + mr <- handleMessage r (SomeMessage FirstLayout) + return . Just . SRight l $ fromMaybe r mr + + -- The default cases for left and right: + handleMessage (SLeft r l) m = fmap (fmap $ SLeft r) $ handleMessage l m + handleMessage (SRight l r) m = fmap (fmap $ SRight l) $ handleMessage r m + +-- +-- | Builtin layout algorithms: +-- +-- > fullscreen mode +-- > tall mode +-- +-- The latter algorithms support the following operations: +-- +-- > Shrink +-- > Expand +-- +data Resize = Shrink | Expand deriving Typeable + +-- | You can also increase the number of clients in the master pane +data IncMasterN = IncMasterN Int deriving Typeable + +instance Message Resize +instance Message IncMasterN + +-- | Simple fullscreen mode, just render all windows fullscreen. +data Full a = Full deriving (Show, Read) + +instance LayoutClass Full a + +-- | The inbuilt tiling mode of xmonad, and its operations. +data Tall a = Tall Int Rational Rational deriving (Show, Read) + +instance LayoutClass Tall a where + pureLayout (Tall nmaster _ frac) r s = zip ws rs + where ws = W.integrate s + rs = tile frac r nmaster (length ws) + + pureMessage (Tall nmaster delta frac) m = msum [fmap resize (fromMessage m) + ,fmap incmastern (fromMessage m)] + where resize Shrink = Tall nmaster delta (max 0 $ frac-delta) + resize Expand = Tall nmaster delta (min 1 $ frac+delta) + incmastern (IncMasterN d) = Tall (max 0 (nmaster+d)) delta frac + description _ = "Tall" + +-- | Mirror a rectangle +mirrorRect :: Rectangle -> Rectangle +mirrorRect (Rectangle rx ry rw rh) = (Rectangle ry rx rh rw) + +-- | Mirror a layout, compute its 90 degree rotated form. +data Mirror l a = Mirror (l a) deriving (Show, Read) + +instance LayoutClass l a => LayoutClass (Mirror l) a where + doLayout (Mirror l) r s = (map (second mirrorRect) *** fmap Mirror) + `fmap` doLayout l (mirrorRect r) s + handleMessage (Mirror l) = fmap (fmap Mirror) . handleMessage l + description (Mirror l) = "Mirror "++ description l + +-- | tile. Compute the positions for windows using the default 2 pane tiling algorithm. +-- +-- The screen is divided (currently) into two panes. all clients are +-- then partioned between these two panes. one pane, the `master', by +-- convention has the least number of windows in it (by default, 1). +-- the variable `nmaster' controls how many windows are rendered in the +-- master pane. +-- +-- `delta' specifies the ratio of the screen to resize by. +-- +-- 'frac' specifies what proportion of the screen to devote to the +-- master area. +-- +tile :: Rational -> Rectangle -> Int -> Int -> [Rectangle] +tile f r nmaster n = if n <= nmaster || nmaster == 0 + then splitVertically n r + else splitVertically nmaster r1 ++ splitVertically (n-nmaster) r2 -- two columns + where (r1,r2) = splitHorizontallyBy f r + +-- +-- Divide the screen vertically into n subrectangles +-- +splitVertically, splitHorizontally :: Int -> Rectangle -> [Rectangle] +splitVertically n r | n < 2 = [r] +splitVertically n (Rectangle sx sy sw sh) = Rectangle sx sy sw smallh : + splitVertically (n-1) (Rectangle sx (sy+fromIntegral smallh) sw (sh-smallh)) + where smallh = sh `div` fromIntegral n --hmm, this is a fold or map. + +splitHorizontally n = map mirrorRect . splitVertically n . mirrorRect + +-- Divide the screen into two rectangles, using a rational to specify the ratio +splitHorizontallyBy, splitVerticallyBy :: RealFrac r => r -> Rectangle -> (Rectangle, Rectangle) +splitHorizontallyBy f (Rectangle sx sy sw sh) = + ( Rectangle sx sy leftw sh + , Rectangle (sx + fromIntegral leftw) sy (sw-fromIntegral leftw) sh) + where leftw = floor $ fromIntegral sw * f + +splitVerticallyBy f = (mirrorRect *** mirrorRect) . splitHorizontallyBy f . mirrorRect |