Move signal handler and data types to own module

This is necessary to make SignalType available for other modules without
import loops. This also decoupels the modules and their functionality a
bit more so this is generally a cleaner solution.

1 files changed, 33 insertions, 0 deletions

diff --git a/src/Signal.hs b/src/Signal.hs
new file mode 100644
index 0000000..3919d86
--- /dev/null
+++ b/src/Signal.hs
@@ -0,0 +1,33 @@
+{-# LANGUAGE DeriveDataTypeable #-}
+
+module Signal where
+
+import Data.Typeable (Typeable)
+import Control.Concurrent
+import Control.Exception hiding (handle)
+import System.Posix.Signals
+
+data WakeUp = WakeUp deriving (Show,Typeable)
+instance Exception WakeUp
+
+data SignalType = Wakeup
+                | Reposition
+                | ChangeScreen
+
+-- | 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 ()