ENH log when bluetooth adapter not found

lib/Xmobar/Plugins/Bluetooth.hs

@@ -76,22 +76,21 @@ startAdapter
 startAdapter is cs cb cl = do
   state <- newMVar emptyState
   let dpy = displayIcon cb (iconFormatter is cs)
-  mapRIO (wrap state) $ do
+  mapRIO (BTEnv state dpy) $ do
     ot <- getBtObjectTree cl
-    -- TODO if this fails it won't be logged
-    forM_ (findAdapter ot) $ \adapter -> do
-      -- set up adapter
-      initAdapter adapter cl
-      void $ addAdaptorListener dpy adapter cl
-      -- set up devices on the adapter (and listeners for adding/removing devices)
-      let devices = findDevices adapter ot
-      addDeviceAddedListener dpy adapter cl
-      addDeviceRemovedListener dpy adapter cl
-      forM_ devices $ \d -> addAndInitDevice dpy d cl
-      -- after setting things up, show the icon based on the initialized state
-      dpy
-  where
-    wrap s env = BTEnv {btEnv = env, btState = s}
+    case findAdapter ot of
+      Nothing -> logError "could not find bluetooth adapter"
+      Just adapter -> do
+        -- set up adapter
+        initAdapter adapter cl
+        void $ addAdaptorListener adapter cl
+        -- set up devices on the adapter (and listeners for adding/removing devices)
+        let devices = findDevices adapter ot
+        addDeviceAddedListener adapter cl
+        addDeviceRemovedListener adapter cl
+        forM_ devices $ \d -> addAndInitDevice d cl
+        -- after setting things up, show the icon based on the initialized state
+        dpy
 
 --------------------------------------------------------------------------------
 -- Icon Display
@@ -123,8 +122,9 @@ iconFormatter (iconConn, iconDisc) cs powered connected =
 -- an MVar.
 
 data BTEnv = BTEnv
-  { btEnv :: !SimpleApp
-  , btState :: !(MVar BtState)
+  { btState :: !(MVar BtState)
+  , btDisplay :: !(BTIO ())
+  , btEnv :: !SimpleApp
   }
 
 instance HasLogFunc BTEnv where
@@ -195,30 +195,25 @@ addBtOMListener
   -> m ()
 addBtOMListener sc = void . addInterfaceAddedListener btBus btOMPath sc
 
-addDeviceAddedListener :: BTIO () -> ObjectPath -> SysClient -> BTIO ()
-addDeviceAddedListener dpy adapter client =
-  addBtOMListener addDevice client
+addDeviceAddedListener :: ObjectPath -> SysClient -> BTIO ()
+addDeviceAddedListener adapter client = addBtOMListener addDevice client
   where
-    addDevice = pathCallback adapter dpy $ \d ->
-      addAndInitDevice dpy d client
+    addDevice = pathCallback adapter $ \d ->
+      addAndInitDevice d client
 
-addDeviceRemovedListener :: BTIO () -> ObjectPath -> SysClient -> BTIO ()
-addDeviceRemovedListener dpy adapter sys =
+addDeviceRemovedListener :: ObjectPath -> SysClient -> BTIO ()
+addDeviceRemovedListener adapter sys =
   addBtOMListener remDevice sys
   where
-    remDevice = pathCallback adapter dpy $ \d -> do
+    remDevice = pathCallback adapter $ \d -> do
       old <- removeDevice d
       forM_ old $ liftIO . removeMatch (toClient sys) . btDevSigHandler
 
-pathCallback
-  :: MonadUnliftIO m
-  => ObjectPath
-  -> m ()
-  -> (ObjectPath -> m ())
-  -> SignalCallback m
-pathCallback adapter dpy f [device, _] = forM_ (fromVariant device) $ \d ->
+pathCallback :: ObjectPath -> (ObjectPath -> BTIO ()) -> SignalCallback BTIO
+pathCallback adapter f [device, _] = forM_ (fromVariant device) $ \d -> do
+  dpy <- asks btDisplay
   when (adaptorHasDevice adapter d) $ f d >> dpy
-pathCallback _ _ _ _ = return ()
+pathCallback _ _ _ = return ()
 
 --------------------------------------------------------------------------------
 -- Adapter
@@ -265,15 +260,11 @@ withBTPropertyRule cl path update iface prop = do
     signalToUpdate = withSignalMatch update
     matchConnected = matchPropertyChanged iface prop
 
-addAdaptorListener
-  :: BTIO ()
-  -> ObjectPath
-  -> SysClient
-  -> BTIO (Maybe SignalHandler)
-addAdaptorListener dpy adaptor sys = do
+addAdaptorListener :: ObjectPath -> SysClient -> BTIO (Maybe SignalHandler)
+addAdaptorListener adaptor sys = do
+  dpy <- asks btDisplay
+  let procMatch b = putPowered b >> dpy
   withBTPropertyRule sys adaptor procMatch adapterInterface adaptorPowered
-  where
-    procMatch b = putPowered b >> dpy
 
 callGetPowered
   :: (MonadReader env m, HasLogFunc env, MonadUnliftIO m)
@@ -300,9 +291,9 @@ adaptorPowered = "Powered"
 --------------------------------------------------------------------------------
 -- Devices
 
-addAndInitDevice :: BTIO () -> ObjectPath -> SysClient -> BTIO ()
-addAndInitDevice dpy device client = do
-  res <- addDeviceListener dpy device client
+addAndInitDevice :: ObjectPath -> SysClient -> BTIO ()
+addAndInitDevice device client = do
+  res <- addDeviceListener device client
   case res of
     Just handler -> do
       logInfo $ "initializing device at path " <> device_
@@ -321,11 +312,11 @@ initDevice sh device sys = do
         , btDevSigHandler = sh
         }
 
-addDeviceListener :: BTIO () -> ObjectPath -> SysClient -> BTIO (Maybe SignalHandler)
-addDeviceListener dpy device sys = do
+addDeviceListener :: ObjectPath -> SysClient -> BTIO (Maybe SignalHandler)
+addDeviceListener device sys = do
+  dpy <- asks btDisplay
+  let procMatch c = updateDevice device c >> dpy
   withBTPropertyRule sys device procMatch devInterface devConnected
-  where
-    procMatch c = updateDevice device c >> dpy
 
 callGetConnected
   :: (MonadReader env m, HasLogFunc env, MonadUnliftIO m)