Allow multiple signals over dbus at once

It's easy to implement, since arguments to dbus method calls are handed
over as list anyway. It also removes the need for safeHead.

Bottom line: extra functionality without extra cost.

2 files changed, 8 insertions, 4 deletions

diff --git a/readme.md b/readme.md
index 6af1568..7bb7adb 100644
--- a/readme.md
+++ b/readme.md
@@ -339,6 +339,11 @@ An example using the `dbus-send` command line utility:
             org.Xmobar.Control.SendSignal \
             "string:Toggle"
 
+It is also possible to send multiple signals at once:
+        # send to another screen, reveal and toggle the persistent flag
+        dbus-send [..] \
+            "string:ChangeScreen" "string:Reveal" "string:TogglePersistent"
+
 
 ## The Output Template
 
diff --git a/src/IPC/DBus.hs b/src/IPC/DBus.hs
index 469a7c6..d755220 100644
--- a/src/IPC/DBus.hs
+++ b/src/IPC/DBus.hs
@@ -18,13 +18,12 @@ import Prelude hiding (catch)
 
 import DBus
 import DBus.Client
-import Control.Monad (join, when)
+import Control.Monad (when)
 import Control.Concurrent
 import Control.Exception (catch)
 import System.IO (stderr, hPutStrLn)
 
 import Signal
-import Plugins.Utils (safeHead)
 
 busName :: BusName
 busName = busName_ "org.Xmobar.Control"
@@ -56,8 +55,8 @@ sendSignalMethod mvst = method interfaceName sendSignalName
 
     sendSignalMethodCall :: MethodCall -> IO Reply
     sendSignalMethodCall mc = do
-        when ( methodCallMember mc == sendSignalName ) $ sendSignal $
-            join $ safeHead $ map fromVariant $ methodCallBody mc
+        when ( methodCallMember mc == sendSignalName )
+             $ mapM_ (sendSignal . fromVariant) (methodCallBody mc)
         return ( replyReturn [] )
 
     sendSignal :: Maybe SignalType -> IO ()