Merge for pull request #53

1 files changed, 70 insertions, 0 deletions

diff --git a/src/Signal.hs b/src/Signal.hs
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+++ b/src/Signal.hs
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+{-# LANGUAGE DeriveDataTypeable, CPP #-}
+
+-----------------------------------------------------------------------------
+-- |
+-- Module      :  Signal
+-- Copyright   :  (c) Andrea Rosatto
+--             :  (c) Jose A. Ortega Ruiz
+--             :  (c) Jochen Keil
+-- License     :  BSD-style (see LICENSE)
+--
+-- Maintainer  :  Jose A. Ortega Ruiz <jao@gnu.org>
+-- Stability   :  unstable
+-- Portability :  unportable
+--
+-- Signal handling, including DBUS when available
+--
+-----------------------------------------------------------------------------
+
+module Signal where
+
+import Data.Typeable (Typeable)
+import Control.Concurrent
+import Control.Exception hiding (handle)
+import System.Posix.Signals
+
+#ifdef DBUS
+import DBus (IsVariant(..))
+import Control.Monad ((>=>))
+
+import Plugins.Utils (safeHead)
+#endif
+
+data WakeUp = WakeUp deriving (Show,Typeable)
+instance Exception WakeUp
+
+data SignalType = Wakeup
+                | Reposition
+                | ChangeScreen
+                | Hide
+                | Reveal
+                | Toggle
+                | TogglePersistent
+    deriving (Read, Show)
+
+#ifdef DBUS
+instance IsVariant SignalType where
+    toVariant   = toVariant . show
+    fromVariant = fromVariant >=> parseSignalType
+#endif
+
+parseSignalType :: String -> Maybe SignalType
+parseSignalType = fmap fst . safeHead . reads
+
+-- | Signal handling
+setupSignalHandler :: IO (MVar SignalType)
+setupSignalHandler = do
+   tid   <- newEmptyMVar
+   installHandler sigUSR2 (Catch $ updatePosHandler tid) Nothing
+   installHandler sigUSR1 (Catch $ changeScreenHandler tid) Nothing
+   return tid
+
+updatePosHandler :: MVar SignalType -> IO ()
+updatePosHandler sig = do
+   putMVar sig Reposition
+   return ()
+
+changeScreenHandler :: MVar SignalType -> IO ()
+changeScreenHandler sig = do
+   putMVar sig ChangeScreen
+   return ()