diff options
| -rw-r--r-- | XMonad/Util/SpawnNamedPipe.hs | 46 |
1 files changed, 40 insertions, 6 deletions
diff --git a/XMonad/Util/SpawnNamedPipe.hs b/XMonad/Util/SpawnNamedPipe.hs index f1477ce..c5d15ac 100644 --- a/XMonad/Util/SpawnNamedPipe.hs +++ b/XMonad/Util/SpawnNamedPipe.hs @@ -10,13 +10,16 @@ -- Stability : unstable -- Portability : not portable -- --- A module for spawning a pipe whose handle lives in the Xmonad state. This --- makes is possible to start dzen in the startup hook and pipe stuff to it in --- the logHook cleanly. +-- A module for spawning a pipe whose "Handle" lives in the Xmonad state. -- ----------------------------------------------------------------------------- -module XMonad.Util.SpawnNamedPipe (spawnNamedPipe, getNamedPipeHandle) where +module XMonad.Util.SpawnNamedPipe ( + -- * Usage + -- $usage + spawnNamedPipe + , getNamedPipe + ) where import XMonad import XMonad.Util.Run @@ -25,12 +28,39 @@ import qualified XMonad.Util.ExtensibleState as XS import Control.Monad import qualified Data.Map.Strict as Map +-- $usage +-- This module makes it possible to spawn a pipe to Dzen2 in the startupHook +-- and write to it from inside the logHook without the need for global +-- variables. +-- +-- > import XMonad.Util.SpawnNamedPipe +-- > import Data.Maybe +-- > +-- > -- StartupHook +-- > startupHook' = spawnNamedPipe "dzen2" "dzenPipe" +-- > +-- > -- LogHook +-- > logHook' = do +-- > mh <- getNamedPipeHandle "dzenPipe" +-- > dynamicLogWithPP $ defaultPP { +-- > ppOutput = maybe (\s -> return ()) (hPutStrLn) mh} +-- > +-- > -- Main +-- > main = xmonad $ defaultConfig { +-- > startupHook = startupHook' +-- > , logHook = logHook'} +-- + data NamedPipes = NamedPipes { pipeMap :: (Map.Map String Handle) } deriving (Show, Typeable) instance ExtensionClass NamedPipes where initialValue = NamedPipes Map.empty +-- | When 'spawnNamedPipe' is executed with a command "String" and a name +-- "String" respectively. The command string is spawned with 'spawnPipe' (as +-- long as the name chosen hasn't been used already) and the "Handle" returned +-- is saved in Xmonad's state associated with the name "String". spawnNamedPipe :: String -> String -> X () spawnNamedPipe cmd name = do b <- XS.gets (Map.member name . pipeMap) @@ -38,5 +68,9 @@ spawnNamedPipe cmd name = do h <- spawnPipe cmd XS.modify (NamedPipes . Map.insert name h . pipeMap) -getNamedPipeHandle :: String -> X (Maybe Handle) -getNamedPipeHandle name = XS.gets (Map.lookup name . pipeMap) +-- | Attempts to retrieve a "Handle" to a pipe previously stored in Xmonad's +-- state associated with the given string via a call to 'spawnNamedPipe'. If the +-- given string doesn't exist in the map stored in Xmonad's state Nothing is +-- returned. +getNamedPipe :: String -> X (Maybe Handle) +getNamedPipe name = XS.gets (Map.lookup name . pipeMap) |