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|
-----------------------------------------------------------------------------
-- |
-- Module : XMonad.hs
-- Copyright : (c) Spencer Janssen 2007
-- License : BSD3-style (see LICENSE)
--
-- Maintainer : sjanssen@cse.unl.edu
-- Stability : unstable
-- Portability : not portable, uses cunning newtype deriving
--
-----------------------------------------------------------------------------
--
-- The X monad, a state monad transformer over IO, for the window
-- manager state, and support routines.
--
module XMonad (
X, WorkSpace, XState(..),runX,
io, withDisplay, isRoot,
spawn, trace, whenJust
) where
import StackSet (StackSet)
import Control.Monad.State
import System.IO
import System.Posix.Process (executeFile, forkProcess, getProcessStatus)
import System.Exit
import Graphics.X11.Xlib
import Control.Exception
-- | XState, the window manager state.
-- Just the display, width, height and a window list
data XState = XState
{ display :: Display
, screen :: {-# UNPACK #-} !ScreenNumber
, theRoot :: {-# UNPACK #-} !Window
, wmdelete :: {-# UNPACK #-} !Atom
, wmprotocols :: {-# UNPACK #-} !Atom
, dimensions :: {-# UNPACK #-} !(Int,Int)
, workspace :: {-# UNPACK #-} !WorkSpace -- ^ workspace list
}
type WorkSpace = StackSet Window
-- | The X monad, a StateT transformer over IO encapuslating the window
-- manager state
newtype X a = X (StateT XState IO a)
deriving (Functor, Monad, MonadIO, MonadState XState)
-- | Run the X monad, given a chunk of X monad code, and an initial state
-- Return the result, and final state
runX :: XState -> X a -> IO ()
runX st (X a) = runStateT a st >> return ()
-- ---------------------------------------------------------------------
-- Convenient wrappers to state
-- | Run a monad action with the current display settings
withDisplay :: (Display -> X ()) -> X ()
withDisplay f = gets display >>= f
-- | True if the given window is the root window
isRoot :: Window -> X Bool
isRoot w = liftM (w==) (gets theRoot)
-- ---------------------------------------------------------------------
-- Utilities
-- | Lift an IO action into the X monad
io :: IO a -> X a
io = liftIO
{-# INLINE io #-}
-- | spawn. Launch an external application
spawn :: String -> X ()
spawn x = io $ do
pid <- forkProcess $ do
forkProcess (executeFile "/bin/sh" False ["-c", x] Nothing)
exitWith ExitSuccess
return ()
getProcessStatus True False pid
return ()
-- | Run a side effecting action with the current workspace. Like 'when' but
whenJust :: Maybe a -> (a -> X ()) -> X ()
whenJust mg f = maybe (return ()) f mg
-- | A 'trace' for the X monad. Logs a string to stderr. The result may
-- be found in your .xsession-errors file
trace :: String -> X ()
trace msg = io $! do hPutStrLn stderr msg; hFlush stderr
|
