1 files changed, 113 insertions, 0 deletions
diff --git a/tv/5pkgs/haskell/xmonad-tv/src/Shutdown.hs b/tv/5pkgs/haskell/xmonad-tv/src/Shutdown.hs
new file mode 100644
index 00000000..d4a4d93c
--- /dev/null
+++ b/tv/5pkgs/haskell/xmonad-tv/src/Shutdown.hs
@@ -0,0 +1,113 @@
+{-# LANGUAGE LambdaCase #-}
+
+module Shutdown
+    ( newShutdownEventHandler
+    , shutdown
+    )
+  where
+
+import Control.Applicative ((<|>), empty)
+import Control.Concurrent (threadDelay)
+import Control.Monad (forever, guard, when)
+import Data.Monoid (All(All))
+import System.Directory (XdgDirectory(XdgData), createDirectoryIfMissing, doesFileExist, getAppUserDataDirectory, getXdgDirectory)
+import System.Exit (exitSuccess)
+import System.Environment (lookupEnv)
+import System.FilePath ((</>))
+import System.IO.Error (isDoesNotExistError, tryIOError)
+import System.IO (hPutStrLn, stderr)
+import System.Posix.Process (getProcessID)
+import System.Posix.Signals (nullSignal, signalProcess)
+import System.Posix.Types (ProcessID)
+import XMonad hiding (getXMonadDataDir)
+
+
+-- XXX this is for compatibility with both xmonad<0.17 and xmonad>=0.17
+getXMonadDataDir :: IO String
+getXMonadDataDir = xmEnvDir <|> xmDir <|> xdgDir
+  where
+    -- | Check for xmonad's environment variables first
+    xmEnvDir :: IO String
+    xmEnvDir =
+        maybe empty pure =<< lookupEnv "XMONAD_DATA_DIR"
+
+    -- | Check whether the config file or a build script is in the
+    -- @~\/.xmonad@ directory
+    xmDir :: IO String
+    xmDir = do
+        d <- getAppUserDataDirectory "xmonad"
+        conf  <- doesFileExist $ d </> "xmonad.hs"
+        build <- doesFileExist $ d </> "build"
+        pid <- doesFileExist $ d </> "xmonad.pid"
+
+        -- Place *everything* in ~/.xmonad if yes
+        guard $ conf || build || pid
+        pure d
+
+    -- | Use XDG directories as a fallback
+    xdgDir :: IO String
+    xdgDir = do
+        d <- getXdgDirectory XdgData "xmonad"
+        d <$ createDirectoryIfMissing True d
+
+
+newShutdownEventHandler :: IO (Event -> X All)
+newShutdownEventHandler = do
+    writeProcessIDToFile
+    return handleShutdownEvent
+
+handleShutdownEvent :: Event -> X All
+handleShutdownEvent = \case
+  ClientMessageEvent { ev_message_type = mt } -> do
+    isShutdownEvent <- (mt ==) <$> getAtom "XMONAD_SHUTDOWN"
+    when isShutdownEvent $ do
+      broadcastMessage ReleaseResources
+      writeStateToFile
+      io exitSuccess >> return ()
+    return (All (not isShutdownEvent))
+  _ ->
+    return (All True)
+
+sendShutdownEvent :: IO ()
+sendShutdownEvent = do
+    dpy <- openDisplay ""
+    rw <- rootWindow dpy $ defaultScreen dpy
+    a <- internAtom dpy "XMONAD_SHUTDOWN" False
+    allocaXEvent $ \e -> do
+        setEventType e clientMessage
+        setClientMessageEvent e rw a 32 0 currentTime
+        sendEvent dpy rw False structureNotifyMask e
+    sync dpy False
+
+shutdown :: IO ()
+shutdown = do
+    pid <- readProcessIDFromFile
+    sendShutdownEvent
+    hPutStrLn stderr ("waiting for: " <> show pid)
+    result <- tryIOError (waitProcess pid)
+    if isSuccess result
+      then hPutStrLn stderr ("result: " <> show result <> " [AKA success^_^]")
+      else hPutStrLn stderr ("result: " <> show result)
+  where
+    isSuccess = either isDoesNotExistError (const False)
+
+waitProcess :: ProcessID -> IO ()
+waitProcess pid = forever (signalProcess nullSignal pid >> threadDelay 10000)
+
+--
+-- PID file stuff
+--
+
+getProcessIDFileName :: IO FilePath
+getProcessIDFileName = (</> "xmonad.pid") <$> getXMonadDataDir
+
+writeProcessIDToFile :: IO ()
+writeProcessIDToFile = do
+    pidFileName <- getProcessIDFileName
+    pid <- getProcessID
+    writeFile pidFileName (show pid)
+
+readProcessIDFromFile :: IO ProcessID
+readProcessIDFromFile = do
+    pidFileName <- getProcessIDFileName
+    read <$> readFile pidFileName