xmonad-config/lib/XMonad/Internal/DBus/Screensaver.hs

112 lines
3.1 KiB
Haskell

{-# LANGUAGE OverloadedStrings #-}
--------------------------------------------------------------------------------
-- | DBus module for X11 screensave/DPMS control
module XMonad.Internal.DBus.Screensaver
( exportScreensaver
, callToggle
, callQuery
, matchSignal
) where
import Control.Monad (void)
import DBus
import DBus.Client
import Graphics.X11.XScreenSaver
import Graphics.X11.Xlib.Display
import XMonad.Internal.DBus.Common
import XMonad.Internal.Process
--------------------------------------------------------------------------------
-- | Low-level functions
type SSState = Bool -- true is enabled
toggle :: IO SSState
toggle = do
st <- query
-- TODO figure out how not to do this with shell commands
void $ createProcess' $ proc "xset" $ "s" : args st
-- TODO this assumes the command succeeds
return $ not st
where
args s = if s then ["off", "-dpms"] else ["on", "+dpms"]
query :: IO SSState
query = do
dpy <- openDisplay ""
xssi <- xScreenSaverQueryInfo dpy
closeDisplay dpy
return $ case xssi of
Just XScreenSaverInfo { xssi_state = ScreenSaverDisabled } -> False
Just XScreenSaverInfo { xssi_state = _ } -> True
-- TODO handle errors better (at least log them?)
Nothing -> False
--------------------------------------------------------------------------------
-- | DBus Interface
--
-- Define a methods to toggle the screensaver. This methods will emit signal
-- with the new state when called. Define another method to get the current
-- state.
path :: ObjectPath
path = "/screensaver"
interface :: InterfaceName
interface = "org.xmonad.Screensaver"
memState :: MemberName
memState = "State"
memToggle :: MemberName
memToggle = "Toggle"
memQuery :: MemberName
memQuery = "Query"
sigCurrentState :: Signal
sigCurrentState = signal path interface memState
ruleCurrentState :: MatchRule
ruleCurrentState = matchAny
{ matchPath = Just path
, matchInterface = Just interface
, matchMember = Just memState
}
emitState :: Client -> SSState -> IO ()
emitState client sss = emit client $ sigCurrentState { signalBody = [toVariant sss] }
bodyGetCurrentState :: [Variant] -> Maybe SSState
bodyGetCurrentState [b] = fromVariant b :: Maybe SSState
bodyGetCurrentState _ = Nothing
--------------------------------------------------------------------------------
-- | Exported haskell API
exportScreensaver :: Client -> IO ()
exportScreensaver client =
export client path defaultInterface
{ interfaceName = interface
, interfaceMethods =
[ autoMethod memToggle $ emitState client =<< toggle
, autoMethod memQuery query
]
}
callToggle :: IO ()
callToggle = void $ callMethod $ methodCall path interface memToggle
callQuery :: IO (Maybe SSState)
callQuery = do
reply <- callMethod $ methodCall path interface memQuery
return $ reply >>= bodyGetCurrentState
matchSignal :: (Maybe SSState -> IO ()) -> IO SignalHandler
matchSignal cb = addMatchCallback ruleCurrentState $ cb . bodyGetCurrentState