Move the IsVariant SignalType instance to Signal module

This belongs here, otherwise ghc will complain about orphaned instances

1 files changed, 17 insertions, 1 deletions

diff --git a/src/Signal.hs b/src/Signal.hs
index ad19fdd..f634c16 100644
--- a/src/Signal.hs
+++ b/src/Signal.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE DeriveDataTypeable #-}
+{-# LANGUAGE DeriveDataTypeable, CPP #-}
 
 module Signal where
 
@@ -7,6 +7,13 @@ 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
 
@@ -19,6 +26,15 @@ data SignalType = Wakeup
                 | 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