1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
|
{-# OPTIONS -fglasgow-exts #-}
-----------------------------------------------------------------------------
-- |
-- 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, WindowSet, WorkspaceId(..), ScreenId(..), XState(..), XConf(..), Layout(..),
Typeable, Message, SomeMessage(..), fromMessage,
runX, io, withDisplay, withWorkspace, isRoot, spawn, restart, trace, whenJust, whenX
) where
import StackSet (StackSet)
import Control.Monad.State
import Control.Monad.Reader
import System.IO
import System.Posix.Process (executeFile, forkProcess, getProcessStatus, createSession)
import System.Exit
import System.Environment
import Graphics.X11.Xlib
import Data.Typeable
import qualified Data.Map as M
-- | XState, the window manager state.
-- Just the display, width, height and a window list
data XState = XState
{ windowset :: !WindowSet -- ^ workspace list
, xineScreens :: ![Rectangle] -- ^ dimensions of each screen
, dimensions :: !(Position,Position) -- ^ dimensions of the screen,
-- used for hiding windows
, layouts :: !(M.Map WorkspaceId (Layout, [Layout])) }
-- ^ mapping of workspaces to descriptions of their layouts
data XConf = XConf
{ display :: Display -- ^ the X11 display
, theRoot :: !Window -- ^ the root window
, wmdelete :: !Atom -- ^ window deletion atom
, wmprotocols :: !Atom -- ^ wm protocols atom
, normalBorder :: !Color -- ^ border color of unfocused windows
, focusedBorder :: !Color } -- ^ border color of the focused window
type WindowSet = StackSet WorkspaceId Window ScreenId
-- | Virtual workspace indicies
newtype WorkspaceId = W Int deriving (Eq,Ord,Show,Read,Enum,Num,Integral,Real)
-- | Physical screen indicies
newtype ScreenId = S Int deriving (Eq,Ord,Show,Read,Enum,Num,Integral,Real)
------------------------------------------------------------------------
-- | The X monad, a StateT transformer over IO encapsulating the window
-- manager state
--
-- Dynamic components may be retrieved with 'get', static components
-- with 'ask'. With newtype deriving we get readers and state monads
-- instantiated on XConf and XState automatically.
--
newtype X a = X (ReaderT XConf (StateT XState IO) a)
deriving (Functor, Monad, MonadIO, MonadState XState, MonadReader XConf)
-- | Run the X monad, given a chunk of X monad code, and an initial state
-- Return the result, and final state
runX :: XConf -> XState -> X a -> IO ()
runX c st (X a) = runStateT (runReaderT a c) st >> return ()
-- ---------------------------------------------------------------------
-- Convenient wrappers to state
-- | Run a monad action with the current display settings
withDisplay :: (Display -> X ()) -> X ()
withDisplay f = asks display >>= f
-- | Run a monadic action with the current workspace
withWorkspace :: (WindowSet -> X a) -> X a
withWorkspace f = gets windowset >>= f
-- | True if the given window is the root window
isRoot :: Window -> X Bool
isRoot w = liftM (w==) (asks theRoot)
------------------------------------------------------------------------
-- Layout handling
-- | The different layout modes
-- 'doLayout', a pure function to layout a Window set 'modifyLayout',
-- 'modifyLayout' can be considered a branch of an exception handler.
--
data Layout = Layout { doLayout :: Rectangle -> [Window] -> X [(Window, Rectangle)]
, modifyLayout :: SomeMessage -> Maybe Layout }
-- Based on ideas in /An Extensible Dynamically-Typed Hierarchy of Exceptions/,
-- Simon Marlow, 2006. Use extensible messages to the modifyLayout handler.
--
-- User-extensible messages must be a member of this class:
--
class Typeable a => Message a
--
-- A wrapped value of some type in the Message class.
--
data SomeMessage = forall a. Message a => SomeMessage a
--
-- And now, unwrap a given, unknown Message type, performing a (dynamic)
-- type check on the result.
--
fromMessage :: Message m => SomeMessage -> Maybe m
fromMessage (SomeMessage m) = cast m
-- ---------------------------------------------------------------------
-- General utilities
-- | Lift an IO action into the X monad
io :: IO a -> X a
io = liftIO
-- | spawn. Launch an external application
spawn :: String -> X ()
spawn x = io $ do
pid <- forkProcess $ do
forkProcess (createSession >> executeFile "/bin/sh" False ["-c", x] Nothing)
exitWith ExitSuccess
return ()
getProcessStatus True False pid
return ()
-- | Restart xmonad via exec().
--
-- If the first parameter is 'Just name', restart will attempt to execute the
-- program corresponding to 'name'. Otherwise, xmonad will attempt to execute
-- the name of the current program.
--
-- When the second parameter is 'True', xmonad will attempt to resume with the
-- current window state.
restart :: Maybe String -> Bool -> X ()
restart mprog resume = do
prog <- maybe (io $ getProgName) return mprog
args <- io $ getArgs
args' <- if resume then gets (("--resume":) . return . show . windowset) else return []
io $ catch (executeFile prog True (args' ++ args) Nothing)
(const $ return ()) -- ignore executable not found exception
-- | 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
-- | Conditionally run an action, using a X event to decide
whenX :: X Bool -> X () -> X ()
whenX a f = a >>= \b -> when b f
-- | Grab the X server (lock it) from the X monad
-- withServerX :: X () -> X ()
-- withServerX f = withDisplay $ \dpy -> do
-- io $ grabServer dpy
-- f
-- io $ ungrabServer dpy
-- | 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
|
