Refactoring: cleaner separation app/lib and more cleanups

9 files changed, 551 insertions, 463 deletions

diff --git a/src/app/Configuration.hs b/src/app/Configuration.hs
index db5c109..e1e3c24 100644
--- a/src/app/Configuration.hs
+++ b/src/app/Configuration.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE FlexibleContexts, CPP #-}
 
 ------------------------------------------------------------------------------
 -- |
@@ -17,14 +17,33 @@
 ------------------------------------------------------------------------------
 
 
-module Configuration (parseConfig) where
+module Configuration (readConfig, readDefaultConfig) where
 
 import Text.ParserCombinators.Parsec
 import Text.ParserCombinators.Parsec.Number (int)
 import Text.ParserCombinators.Parsec.Perm ((<|?>), (<$?>), permute)
+import Control.Monad.IO.Class (liftIO)
+
+import System.Posix.Files
+import System.FilePath ((</>))
+import System.Environment
+import System.Directory (getHomeDirectory)
+
+import Xmobar.Config
 
 import qualified Xmobar.Config as C
 
+#if defined XFT || defined UTF8
+import qualified System.IO as S (readFile,hGetLine)
+#endif
+
+readFileSafe :: FilePath -> IO String
+#if defined XFT || defined UTF8
+readFileSafe = S.readFile
+#else
+readFileSafe = readFile
+#endif
+
 stripComments :: String -> String
 stripComments =
   unlines . map (drop 5 . strip False . (replicate 5 ' '++)) . lines
@@ -156,3 +175,39 @@ commandsErr = "commands: this usually means that a command could not" ++
               "\nbe parsed." ++
               "\nThe error could be located at the begining of the command" ++
               "\nwhich follows the offending one."
+
+-- | Reads the configuration files or quits with an error
+readConfig :: FilePath -> String -> IO (Config,[String])
+readConfig f usage = do
+  file <- liftIO $ fileExist f
+  s <- liftIO $ if file then readFileSafe f else error $
+                  f ++ ": file not found!\n" ++ usage
+  either (\err -> error $ f ++
+                    ": configuration file contains errors at:\n" ++ show err)
+         return $ parseConfig s
+
+xdgConfigDir :: IO String
+xdgConfigDir = do env <- getEnvironment
+                  case lookup "XDG_CONFIG_HOME" env of
+                       Just val -> return val
+                       Nothing  -> fmap (</> ".config") getHomeDirectory
+
+xmobarConfigDir :: IO FilePath
+xmobarConfigDir = fmap (</> "xmobar") xdgConfigDir
+
+getXdgConfigFile :: IO FilePath
+getXdgConfigFile = fmap (</> "xmobarrc") xmobarConfigDir
+
+-- | Read default configuration file or load the default config
+readDefaultConfig :: String -> IO (Config,[String])
+readDefaultConfig usage = do
+  xdgConfigFile <- getXdgConfigFile
+  xdgConfigFileExists <- liftIO $ fileExist xdgConfigFile
+  home <- liftIO $ getEnv "HOME"
+  let defaultConfigFile = home ++ "/.xmobarrc"
+  defaultConfigFileExists <- liftIO $ fileExist defaultConfigFile
+  if xdgConfigFileExists
+    then readConfig xdgConfigFile usage
+    else if defaultConfigFileExists
+         then readConfig defaultConfigFile usage
+         else return (defaultConfig,[])
diff --git a/src/app/Main.hs b/src/app/Main.hs
index 22834b1..0760d16 100644
--- a/src/app/Main.hs
+++ b/src/app/Main.hs
@@ -13,126 +13,35 @@
 --
 -----------------------------------------------------------------------------
 
-module Main ( -- * Main Stuff
-              -- $main
-              main
-            , readConfig
-            , readDefaultConfig
-            ) where
+module Main (main) where
 
-import Xmobar
-import Xmobar.Parsers
-import Xmobar.Config
-import Xmobar.XUtil
-
-import Data.Foldable (for_)
 import Data.List (intercalate)
-import qualified Data.Map as Map
 
 import Data.Version (showVersion)
-import Graphics.X11.Xlib
 import System.Console.GetOpt
-import System.Directory (getHomeDirectory)
 import System.Exit
-import System.Environment
-import System.FilePath ((</>))
-import System.Posix.Files
-import Control.Concurrent.Async (Async, cancel)
-import Control.Exception (bracket)
+import System.Environment (getArgs)
 import Control.Monad (unless)
-import Control.Monad.IO.Class (liftIO)
 import Text.Read (readMaybe)
 
-import Xmobar.Signal (setupSignalHandler, withDeferSignals)
+import Xmobar (xmobar)
+import Xmobar.Config
 
 import Paths_xmobar (version)
-import Configuration
+import Configuration (readConfig, readDefaultConfig)
 
 -- $main
 
 -- | The main entry point
 main :: IO ()
-main = withDeferSignals $ do
-  initThreads
-  d <- openDisplay ""
-  args <- getArgs
-  (o,file) <- getOpts args
+main = do
+  (o,file) <- getArgs >>= getOpts
   (c,defaultings) <- case file of
-                       [cfgfile] -> readConfig cfgfile
-                       _ -> readDefaultConfig
-
+                       [cfgfile] -> readConfig cfgfile usage
+                       _ -> readDefaultConfig usage
   unless (null defaultings) $ putStrLn $
     "Fields missing from config defaulted: " ++ intercalate "," defaultings
-
-  conf  <- doOpts c o
-  fs    <- initFont d (font conf)
-  fl    <- mapM (initFont d) (additionalFonts conf)
-  cls   <- mapM (parseTemplate conf) (splitTemplate conf)
-  sig   <- setupSignalHandler
-  bracket (mapM (mapM $ startCommand sig) cls)
-          cleanupThreads
-          $ \vars -> do
-    (r,w) <- createWin d fs conf
-    let ic = Map.empty
-        to = textOffset conf
-        ts = textOffsets conf ++ replicate (length fl) (-1)
-    startLoop (XConf d r w (fs:fl) (to:ts) ic conf) sig vars
-
-cleanupThreads :: [[([Async ()], a)]] -> IO ()
-cleanupThreads vars =
-  -- putStrLn "In cleanupThreads"
-  for_ (concat vars) $ \(asyncs, _) ->
-    for_ asyncs cancel
-
--- | Splits the template in its parts
-splitTemplate :: Config -> [String]
-splitTemplate conf =
-  case break (==l) t of
-    (le,_:re) -> case break (==r) re of
-                   (ce,_:ri) -> [le, ce, ri]
-                   _         -> def
-    _         -> def
-  where [l, r] = alignSep
-                   (if length (alignSep conf) == 2 then conf else defaultConfig)
-        t = template conf
-        def = [t, "", ""]
-
-
--- | Reads the configuration files or quits with an error
-readConfig :: FilePath -> IO (Config,[String])
-readConfig f = do
-  file <- liftIO $ fileExist f
-  s <- liftIO $ if file then readFileSafe f else error $
-                  f ++ ": file not found!\n" ++ usage
-  either (\err -> error $ f ++
-                    ": configuration file contains errors at:\n" ++ show err)
-         return $ parseConfig s
-
-xdgConfigDir :: IO String
-xdgConfigDir = do env <- getEnvironment
-                  case lookup "XDG_CONFIG_HOME" env of
-                       Just val -> return val
-                       Nothing  -> fmap (</> ".config") getHomeDirectory
-
-xmobarConfigDir :: IO FilePath
-xmobarConfigDir = fmap (</> "xmobar") xdgConfigDir
-
-getXdgConfigFile :: IO FilePath
-getXdgConfigFile = fmap (</> "xmobarrc") xmobarConfigDir
-
--- | Read default configuration file or load the default config
-readDefaultConfig :: IO (Config,[String])
-readDefaultConfig = do
-  xdgConfigFile <- getXdgConfigFile
-  xdgConfigFileExists <- liftIO $ fileExist xdgConfigFile
-  home <- liftIO $ getEnv "HOME"
-  let defaultConfigFile = home ++ "/.xmobarrc"
-  defaultConfigFileExists <- liftIO $ fileExist defaultConfigFile
-  if xdgConfigFileExists
-    then readConfig xdgConfigFile
-    else if defaultConfigFileExists
-         then readConfig defaultConfigFile
-         else return (defaultConfig,[])
+  doOpts c o >>= xmobar
 
 data Opts = Help
           | Version
diff --git a/src/lib/Xmobar.hs b/src/lib/Xmobar.hs
index 4172780..722ee72 100644
--- a/src/lib/Xmobar.hs
+++ b/src/lib/Xmobar.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE CPP #-}
+
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Xmobar
@@ -14,349 +15,55 @@
 --
 -----------------------------------------------------------------------------
 
-module Xmobar
-    ( -- * Main Stuff
-      -- $main
-      X , XConf (..), runX
-    , startLoop
-    -- * Program Execution
-    -- $command
-    , startCommand
-    -- * Window Management
-    -- $window
-    , createWin
-    -- * Printing
-    -- $print
-    , drawInWin, printStrings
-    ) where
-
-import Prelude hiding (lookup)
-import Graphics.X11.Xlib hiding (textExtents, textWidth)
-import Graphics.X11.Xlib.Extras
-import Graphics.X11.Xinerama
-import Graphics.X11.Xrandr
-
-import Control.Arrow ((&&&))
-import Control.Applicative ((<$>))
-import Control.Monad.Reader
-import Control.Concurrent
-import Control.Concurrent.Async (Async, async)
-import Control.Concurrent.STM
-import Control.Exception (handle, SomeException(..))
-import Data.Bits
-import Data.Map hiding (foldr, map, filter)
-import Data.Maybe (fromJust, isJust)
+module Xmobar (xmobar) where
 
-import Xmobar.Bitmap as Bitmap
+import Xmobar.EventLoop (startLoop, startCommand)
 import Xmobar.Config
-import Xmobar.Parsers
-import Xmobar.Commands
-import Xmobar.Actions
-import Xmobar.Runnable
-import Xmobar.Signal
-import Xmobar.Window
-import Xmobar.XUtil
-import Xmobar.ColorCache
-
-#ifdef XFT
-import Graphics.X11.Xft
-import Xmobar.MinXft (drawBackground)
-#endif
-
-#ifdef DBUS
-import Xmobar.IPC.DBus
-#endif
-
--- $main
---
--- The Xmobar data type and basic loops and functions.
-
--- | The X type is a ReaderT
-type X = ReaderT XConf IO
-
--- | The ReaderT inner component
-data XConf =
-    XConf { display   :: Display
-          , rect      :: Rectangle
-          , window    :: Window
-          , fontListS :: [XFont]
-          , verticalOffsets :: [Int]
-          , iconS     :: Map FilePath Bitmap
-          , config    :: Config
-          }
-
--- | Runs the ReaderT
-runX :: XConf -> X () -> IO ()
-runX xc f = runReaderT f xc
-
--- | Starts the main event loop and threads
-startLoop :: XConf -> TMVar SignalType -> [[([Async ()], TVar String)]]
-             -> IO ()
-startLoop xcfg@(XConf _ _ w _ _ _ _) sig vs = do
-#ifdef XFT
-    xftInitFtLibrary
-#endif
-    tv <- atomically $ newTVar []
-    _ <- forkIO (handle (handler "checker") (checker tv [] vs sig))
-#ifdef THREADED_RUNTIME
-    _ <- forkOS (handle (handler "eventer") (eventer sig))
-#else
-    _ <- forkIO (handle (handler "eventer") (eventer sig))
-#endif
-#ifdef DBUS
-    runIPC sig
-#endif
-    eventLoop tv xcfg [] sig
-  where
-    handler thing (SomeException e) =
-      void $ putStrLn ("Thread " ++ thing ++ " failed: " ++ show e)
-    -- Reacts on events from X
-    eventer signal =
-      allocaXEvent $ \e -> do
-        dpy <- openDisplay ""
-        xrrSelectInput dpy (defaultRootWindow dpy) rrScreenChangeNotifyMask
-        selectInput dpy w (exposureMask .|. structureNotifyMask .|. buttonPressMask)
-
-        forever $ do
-#ifdef THREADED_RUNTIME
-          nextEvent dpy e
-#else
-          nextEvent' dpy e
-#endif
-          ev <- getEvent e
-          case ev of
-            ConfigureEvent {} -> atomically $ putTMVar signal Reposition
-            ExposeEvent {} -> atomically $ putTMVar signal Wakeup
-            RRScreenChangeNotifyEvent {} -> atomically $ putTMVar signal Reposition
-            ButtonEvent {} -> atomically $ putTMVar signal (Action (ev_button ev) (fi $ ev_x ev))
-            _ -> return ()
-
--- | Send signal to eventLoop every time a var is updated
-checker :: TVar [String]
-           -> [String]
-           -> [[([Async ()], TVar String)]]
-           -> TMVar SignalType
-           -> IO ()
-checker tvar ov vs signal = do
-      nval <- atomically $ do
-              nv <- mapM concatV vs
-              guard (nv /= ov)
-              writeTVar tvar nv
-              return nv
-      atomically $ putTMVar signal Wakeup
-      checker tvar nval vs signal
-    where
-      concatV = fmap concat . mapM (readTVar . snd)
-
-
--- | Continuously wait for a signal from a thread or a interrupt handler
-eventLoop :: TVar [String]
-             -> XConf
-             -> [([Action], Position, Position)]
-             -> TMVar SignalType
-             -> IO ()
-eventLoop tv xc@(XConf d r w fs vos is cfg) as signal = do
-      typ <- atomically $ takeTMVar signal
-      case typ of
-         Wakeup -> do
-            str <- updateString cfg tv
-            xc' <- updateCache d w is (iconRoot cfg) str >>=
-                     \c -> return xc { iconS = c }
-            as' <- updateActions xc r str
-            runX xc' $ drawInWin r str
-            eventLoop tv xc' as' signal
-
-         Reposition ->
-            reposWindow cfg
-
-         ChangeScreen -> do
-            ncfg <- updateConfigPosition cfg
-            reposWindow ncfg
 
-         Hide   t -> hide   (t*100*1000)
-         Reveal t -> reveal (t*100*1000)
-         Toggle t -> toggle t
+import Data.Foldable (for_)
+import qualified Data.Map as Map
 
-         TogglePersistent -> eventLoop
-            tv xc { config = cfg { persistent = not $ persistent cfg } } as signal
+import Graphics.X11.Xlib
+import Control.Concurrent.Async (Async, cancel)
+import Control.Exception (bracket)
 
-         Action but x -> action but x
-
-    where
-        isPersistent = not $ persistent cfg
-
-        hide t
-            | t == 0 =
-                when isPersistent (hideWindow d w) >> eventLoop tv xc as signal
-            | otherwise = do
-                void $ forkIO
-                     $ threadDelay t >> atomically (putTMVar signal $ Hide 0)
-                eventLoop tv xc as signal
-
-        reveal t
-            | t == 0 = do
-                when isPersistent (showWindow r cfg d w)
-                eventLoop tv xc as signal
-            | otherwise = do
-                void $ forkIO
-                     $ threadDelay t >> atomically (putTMVar signal $ Reveal 0)
-                eventLoop tv xc as signal
-
-        toggle t = do
-            ismapped <- isMapped d w
-            atomically (putTMVar signal $ if ismapped then Hide t else Reveal t)
-            eventLoop tv xc as signal
-
-        reposWindow rcfg = do
-          r' <- repositionWin d w (head fs) rcfg
-          eventLoop tv (XConf d r' w fs vos is rcfg) as signal
-
-        updateConfigPosition ocfg =
-          case position ocfg of
-            OnScreen n o -> do
-              srs <- getScreenInfo d
-              return (if n == length srs
-                       then
-                        (ocfg {position = OnScreen 1 o})
-                       else
-                        (ocfg {position = OnScreen (n+1) o}))
-            o -> return (ocfg {position = OnScreen 1 o})
-
-        action button x = do
-          mapM_ runAction $
-            filter (\(Spawn b _) -> button `elem` b) $
-            concatMap (\(a,_,_) -> a) $
-            filter (\(_, from, to) -> x >= from && x <= to) as
-          eventLoop tv xc as signal
-
--- $command
-
--- | Runs a command as an independent thread and returns its Async handles
--- and the TVar the command will be writing to.
-startCommand :: TMVar SignalType
-             -> (Runnable,String,String)
-             -> IO ([Async ()], TVar String)
-startCommand sig (com,s,ss)
-    | alias com == "" = do var <- atomically $ newTVar is
-                           atomically $ writeTVar var (s ++ ss)
-                           return ([], var)
-    | otherwise = do var <- atomically $ newTVar is
-                     let cb str = atomically $ writeTVar var (s ++ str ++ ss)
-                     a1 <- async $ start com cb
-                     a2 <- async $ trigger com $ maybe (return ())
-                                                 (atomically . putTMVar sig)
-                     return ([a1, a2], var)
-    where is = s ++ "Updating..." ++ ss
-
-updateString :: Config -> TVar [String]
-                -> IO [[(Widget, String, Int, Maybe [Action])]]
-updateString conf v = do
-  s <- readTVarIO v
-  let l:c:r:_ = s ++ repeat ""
-  liftIO $ mapM (parseString conf) [l, c, r]
-
-updateActions :: XConf -> Rectangle -> [[(Widget, String, Int, Maybe [Action])]]
-                 -> IO [([Action], Position, Position)]
-updateActions conf (Rectangle _ _ wid _) ~[left,center,right] = do
-  let (d,fs) = (display &&& fontListS) conf
-      strLn :: [(Widget, String, Int, Maybe [Action])] -> IO [(Maybe [Action], Position, Position)]
-      strLn  = liftIO . mapM getCoords
-      iconW i = maybe 0 Bitmap.width (lookup i $ iconS conf)
-      getCoords (Text s,_,i,a) = textWidth d (fs!!i) s >>= \tw -> return (a, 0, fi tw)
-      getCoords (Icon s,_,_,a) = return (a, 0, fi $ iconW s)
-      partCoord off xs = map (\(a, x, x') -> (fromJust a, x, x')) $
-                         filter (\(a, _,_) -> isJust a) $
-                         scanl (\(_,_,x') (a,_,w') -> (a, x', x' + w'))
-                               (Nothing, 0, off)
-                               xs
-      totSLen = foldr (\(_,_,len) -> (+) len) 0
-      remWidth xs = fi wid - totSLen xs
-      offs = 1
-      offset a xs = case a of
-                     C -> (remWidth xs + offs) `div` 2
-                     R -> remWidth xs
-                     L -> offs
-  fmap concat $ mapM (\(a,xs) ->
-                       (\xs' -> partCoord (offset a xs') xs') <$> strLn xs) $
-                     zip [L,C,R] [left,center,right]
-
--- $print
-
--- | Draws in and updates the window
-drawInWin :: Rectangle -> [[(Widget, String, Int, Maybe [Action])]] -> X ()
-drawInWin wr@(Rectangle _ _ wid ht) ~[left,center,right] = do
-  r <- ask
-  let (c,d) = (config &&& display) r
-      (w,(fs,vs)) = (window &&& fontListS &&& verticalOffsets) r
-      strLn = liftIO . mapM getWidth
-      iconW i = maybe 0 Bitmap.width (lookup i $ iconS r)
-      getWidth (Text s,cl,i,_) =
-        textWidth d (fs!!i) s >>= \tw -> return (Text s,cl,i,fi tw)
-      getWidth (Icon s,cl,i,_) = return (Icon s,cl,i,fi $ iconW s)
-
-  p <- liftIO $ createPixmap d w wid ht
-                         (defaultDepthOfScreen (defaultScreenOfDisplay d))
-#if XFT
-  when (alpha c /= 255) (liftIO $ drawBackground d p (bgColor c) (alpha c) wr)
-#endif
-  withColors d [bgColor c, borderColor c] $ \[bgcolor, bdcolor] -> do
-    gc <- liftIO $ createGC  d w
-#if XFT
-    when (alpha c == 255) $ do
-#else
-    do
-#endif
-      liftIO $ setForeground d gc bgcolor
-      liftIO $ fillRectangle d p gc 0 0 wid ht
-    -- write to the pixmap the new string
-    printStrings p gc fs vs 1 L =<< strLn left
-    printStrings p gc fs vs 1 R =<< strLn right
-    printStrings p gc fs vs 1 C =<< strLn center
-    -- draw border if requested
-    liftIO $ drawBorder (border c) (borderWidth c) d p gc bdcolor wid ht
-    -- copy the pixmap with the new string to the window
-    liftIO $ copyArea d p w gc 0 0 wid ht 0 0
-    -- free up everything (we do not want to leak memory!)
-    liftIO $ freeGC d gc
-    liftIO $ freePixmap d p
-    -- resync
-    liftIO $ sync d True
-
-verticalOffset :: (Integral b, Integral a, MonadIO m) =>
-                  a -> Widget -> XFont -> Int -> Config -> m b
-verticalOffset ht (Text t) fontst voffs _
-  | voffs > -1 = return $ fi voffs
-  | otherwise = do
-     (as,ds) <- liftIO $ textExtents fontst t
-     let margin = (fi ht - fi ds - fi as) `div` 2
-     return $ fi as + margin - 1
-verticalOffset ht (Icon _) _ _ conf
-  | iconOffset conf > -1 = return $ fi (iconOffset conf)
-  | otherwise = return $ fi (ht `div` 2) - 1
-
--- | An easy way to print the stuff we need to print
-printStrings :: Drawable -> GC -> [XFont] -> [Int] -> Position
-             -> Align -> [(Widget, String, Int, Position)] -> X ()
-printStrings _ _ _ _ _ _ [] = return ()
-printStrings dr gc fontlist voffs offs a sl@((s,c,i,l):xs) = do
-  r <- ask
-  let (conf,d) = (config &&& display) r
-      alph = alpha conf
-      Rectangle _ _ wid ht = rect r
-      totSLen = foldr (\(_,_,_,len) -> (+) len) 0 sl
-      remWidth = fi wid - fi totSLen
-      fontst = fontlist !! i
-      offset = case a of
-                 C -> (remWidth + offs) `div` 2
-                 R -> remWidth
-                 L -> offs
-      (fc,bc) = case break (==',') c of
-                 (f,',':b) -> (f, b           )
-                 (f,    _) -> (f, bgColor conf)
-  valign <- verticalOffset ht s (head fontlist) (voffs !! i) conf
-  case s of
-    (Text t) -> liftIO $ printString d dr fontst gc fc bc offset valign t alph
-    (Icon p) -> liftIO $ maybe (return ())
-                           (drawBitmap d dr gc fc bc offset valign)
-                           (lookup p (iconS r))
-  printStrings dr gc fontlist voffs (offs + l) a xs
+import Xmobar.Parsers
+import Xmobar.XUtil
+import Xmobar.Config()
+import Xmobar.Signal (setupSignalHandler, withDeferSignals)
+import Xmobar.Window
+import Xmobar.Types
+
+splitTemplate :: Config -> [String]
+splitTemplate conf =
+  case break (==l) t of
+    (le,_:re) -> case break (==r) re of
+                   (ce,_:ri) -> [le, ce, ri]
+                   _         -> def
+    _         -> def
+  where [l, r] = alignSep
+                   (if length (alignSep conf) == 2 then conf else defaultConfig)
+        t = template conf
+        def = [t, "", ""]
+
+xmobar :: Config -> IO ()
+xmobar conf = withDeferSignals $ do
+  initThreads
+  d <- openDisplay ""
+  fs    <- initFont d (font conf)
+  fl    <- mapM (initFont d) (additionalFonts conf)
+  cls   <- mapM (parseTemplate conf) (splitTemplate conf)
+  sig   <- setupSignalHandler
+  bracket (mapM (mapM $ startCommand sig) cls)
+          cleanupThreads
+          $ \vars -> do
+    (r,w) <- createWin d fs conf
+    let ic = Map.empty
+        to = textOffset conf
+        ts = textOffsets conf ++ replicate (length fl) (-1)
+    startLoop (XConf d r w (fs:fl) (to:ts) ic conf) sig vars
+
+cleanupThreads :: [[([Async ()], a)]] -> IO ()
+cleanupThreads vars =
+  for_ (concat vars) $ \(asyncs, _) ->
+    for_ asyncs cancel
diff --git a/src/lib/Xmobar/Draw.hs b/src/lib/Xmobar/Draw.hs
new file mode 100644
index 0000000..e63cd27
--- /dev/null
+++ b/src/lib/Xmobar/Draw.hs
@@ -0,0 +1,123 @@
+{-# LANGUAGE CPP #-}
+
+------------------------------------------------------------------------------
+-- |
+-- Module: Xmobar.Draw
+-- Copyright: (c) 2018 Jose Antonio Ortega Ruiz
+-- License: BSD3-style (see LICENSE)
+--
+-- Maintainer: jao@gnu.org
+-- Stability: unstable
+-- Portability: portable
+-- Created: Sat Nov 24, 2018 18:49
+--
+--
+-- Drawing the xmobar contents
+--
+------------------------------------------------------------------------------
+
+
+module Xmobar.Draw (drawInWin) where
+
+import Prelude hiding (lookup)
+import Control.Monad.IO.Class
+import Control.Monad.Reader
+import Control.Arrow ((&&&))
+import Data.Map hiding (foldr, map, filter)
+
+import Graphics.X11.Xlib hiding (textExtents, textWidth)
+
+import Xmobar.Parsers (Widget(..))
+import Xmobar.Actions (Action(..))
+import qualified Xmobar.Bitmap as B
+import Xmobar.Types
+import Xmobar.XUtil
+import Xmobar.Config
+import Xmobar.ColorCache
+import Xmobar.Window (drawBorder)
+
+#ifdef XFT
+import Xmobar.MinXft (drawBackground)
+#endif
+
+fi :: (Integral a, Num b) => a -> b
+fi = fromIntegral
+
+-- | Draws in and updates the window
+drawInWin :: Rectangle -> [[(Widget, String, Int, Maybe [Action])]] -> X ()
+drawInWin wr@(Rectangle _ _ wid ht) ~[left,center,right] = do
+  r <- ask
+  let (c,d) = (config &&& display) r
+      (w,(fs,vs)) = (window &&& fontListS &&& verticalOffsets) r
+      strLn = liftIO . mapM getWidth
+      iconW i = maybe 0 B.width (lookup i $ iconS r)
+      getWidth (Text s,cl,i,_) =
+        textWidth d (fs!!i) s >>= \tw -> return (Text s,cl,i,fi tw)
+      getWidth (Icon s,cl,i,_) = return (Icon s,cl,i,fi $ iconW s)
+
+  p <- liftIO $ createPixmap d w wid ht
+                         (defaultDepthOfScreen (defaultScreenOfDisplay d))
+#if XFT
+  when (alpha c /= 255) (liftIO $ drawBackground d p (bgColor c) (alpha c) wr)
+#endif
+  withColors d [bgColor c, borderColor c] $ \[bgcolor, bdcolor] -> do
+    gc <- liftIO $ createGC  d w
+#if XFT
+    when (alpha c == 255) $ do
+#else
+    do
+#endif
+      liftIO $ setForeground d gc bgcolor
+      liftIO $ fillRectangle d p gc 0 0 wid ht
+    -- write to the pixmap the new string
+    printStrings p gc fs vs 1 L =<< strLn left
+    printStrings p gc fs vs 1 R =<< strLn right
+    printStrings p gc fs vs 1 C =<< strLn center
+    -- draw border if requested
+    liftIO $ drawBorder (border c) (borderWidth c) d p gc bdcolor wid ht
+    -- copy the pixmap with the new string to the window
+    liftIO $ copyArea d p w gc 0 0 wid ht 0 0
+    -- free up everything (we do not want to leak memory!)
+    liftIO $ freeGC d gc
+    liftIO $ freePixmap d p
+    -- resync
+    liftIO $ sync d True
+
+verticalOffset :: (Integral b, Integral a, MonadIO m) =>
+                  a -> Widget -> XFont -> Int -> Config -> m b
+verticalOffset ht (Text t) fontst voffs _
+  | voffs > -1 = return $ fi voffs
+  | otherwise = do
+     (as,ds) <- liftIO $ textExtents fontst t
+     let margin = (fi ht - fi ds - fi as) `div` 2
+     return $ fi as + margin - 1
+verticalOffset ht (Icon _) _ _ conf
+  | iconOffset conf > -1 = return $ fi (iconOffset conf)
+  | otherwise = return $ fi (ht `div` 2) - 1
+
+-- | An easy way to print the stuff we need to print
+printStrings :: Drawable -> GC -> [XFont] -> [Int] -> Position
+             -> Align -> [(Widget, String, Int, Position)] -> X ()
+printStrings _ _ _ _ _ _ [] = return ()
+printStrings dr gc fontlist voffs offs a sl@((s,c,i,l):xs) = do
+  r <- ask
+  let (conf,d) = (config &&& display) r
+      alph = alpha conf
+      Rectangle _ _ wid ht = rect r
+      totSLen = foldr (\(_,_,_,len) -> (+) len) 0 sl
+      remWidth = fi wid - fi totSLen
+      fontst = fontlist !! i
+      offset = case a of
+                 C -> (remWidth + offs) `div` 2
+                 R -> remWidth
+                 L -> offs
+      (fc,bc) = case break (==',') c of
+                 (f,',':b) -> (f, b           )
+                 (f,    _) -> (f, bgColor conf)
+  valign <- verticalOffset ht s (head fontlist) (voffs !! i) conf
+  case s of
+    (Text t) -> liftIO $ printString d dr fontst gc fc bc offset valign t alph
+    (Icon p) -> liftIO $ maybe (return ())
+                           (B.drawBitmap d dr gc fc bc offset valign)
+                           (lookup p (iconS r))
+  printStrings dr gc fontlist voffs (offs + l) a xs
diff --git a/src/lib/Xmobar/EventLoop.hs b/src/lib/Xmobar/EventLoop.hs
new file mode 100644
index 0000000..27fcf6d
--- /dev/null
+++ b/src/lib/Xmobar/EventLoop.hs
@@ -0,0 +1,250 @@
+{-# LANGUAGE CPP #-}
+
+------------------------------------------------------------------------------
+-- |
+-- Module: Xmobar.EventLoop
+-- Copyright: (c) 2018 Jose Antonio Ortega Ruiz
+-- License: BSD3-style (see LICENSE)
+--
+-- Maintainer: jao@gnu.org
+-- Stability: unstable
+-- Portability: portable
+-- Created: Sat Nov 24, 2018 19:40
+--
+--
+-- Event loop
+--
+------------------------------------------------------------------------------
+
+
+module Xmobar.EventLoop (startLoop, startCommand) where
+
+import Prelude hiding (lookup)
+import Graphics.X11.Xlib hiding (textExtents, textWidth)
+import Graphics.X11.Xlib.Extras
+import Graphics.X11.Xinerama
+import Graphics.X11.Xrandr
+
+import Control.Arrow ((&&&))
+import Control.Applicative ((<$>))
+import Control.Monad.Reader
+import Control.Concurrent
+import Control.Concurrent.Async (Async, async)
+import Control.Concurrent.STM
+import Control.Exception (handle, SomeException(..))
+import Data.Bits
+import Data.Map hiding (foldr, map, filter)
+import Data.Maybe (fromJust, isJust)
+
+import Xmobar.Bitmap as Bitmap
+import Xmobar.Config
+import Xmobar.Parsers
+import Xmobar.Commands
+import Xmobar.Actions
+import Xmobar.Runnable
+import Xmobar.Signal
+import Xmobar.Window
+import Xmobar.XUtil
+import Xmobar.Draw
+import Xmobar.Types
+
+#ifdef XFT
+import Graphics.X11.Xft
+#endif
+
+#ifdef DBUS
+import Xmobar.IPC.DBus
+#endif
+
+-- $main
+
+-- | Starts the main event loop and threads
+startLoop :: XConf -> TMVar SignalType -> [[([Async ()], TVar String)]]
+             -> IO ()
+startLoop xcfg@(XConf _ _ w _ _ _ _) sig vs = do
+#ifdef XFT
+    xftInitFtLibrary
+#endif
+    tv <- atomically $ newTVar []
+    _ <- forkIO (handle (handler "checker") (checker tv [] vs sig))
+#ifdef THREADED_RUNTIME
+    _ <- forkOS (handle (handler "eventer") (eventer sig))
+#else
+    _ <- forkIO (handle (handler "eventer") (eventer sig))
+#endif
+#ifdef DBUS
+    runIPC sig
+#endif
+    eventLoop tv xcfg [] sig
+  where
+    handler thing (SomeException e) =
+      void $ putStrLn ("Thread " ++ thing ++ " failed: " ++ show e)
+    -- Reacts on events from X
+    eventer signal =
+      allocaXEvent $ \e -> do
+        dpy <- openDisplay ""
+        xrrSelectInput dpy (defaultRootWindow dpy) rrScreenChangeNotifyMask
+        selectInput dpy w (exposureMask .|. structureNotifyMask .|. buttonPressMask)
+
+        forever $ do
+#ifdef THREADED_RUNTIME
+          nextEvent dpy e
+#else
+          nextEvent' dpy e
+#endif
+          ev <- getEvent e
+          case ev of
+            ConfigureEvent {} -> atomically $ putTMVar signal Reposition
+            ExposeEvent {} -> atomically $ putTMVar signal Wakeup
+            RRScreenChangeNotifyEvent {} -> atomically $ putTMVar signal Reposition
+            ButtonEvent {} -> atomically $ putTMVar signal (Action (ev_button ev) (fi $ ev_x ev))
+            _ -> return ()
+
+-- | Send signal to eventLoop every time a var is updated
+checker :: TVar [String]
+           -> [String]
+           -> [[([Async ()], TVar String)]]
+           -> TMVar SignalType
+           -> IO ()
+checker tvar ov vs signal = do
+      nval <- atomically $ do
+              nv <- mapM concatV vs
+              guard (nv /= ov)
+              writeTVar tvar nv
+              return nv
+      atomically $ putTMVar signal Wakeup
+      checker tvar nval vs signal
+    where
+      concatV = fmap concat . mapM (readTVar . snd)
+
+
+-- | Continuously wait for a signal from a thread or a interrupt handler
+eventLoop :: TVar [String]
+             -> XConf
+             -> [([Action], Position, Position)]
+             -> TMVar SignalType
+             -> IO ()
+eventLoop tv xc@(XConf d r w fs vos is cfg) as signal = do
+      typ <- atomically $ takeTMVar signal
+      case typ of
+         Wakeup -> do
+            str <- updateString cfg tv
+            xc' <- updateCache d w is (iconRoot cfg) str >>=
+                     \c -> return xc { iconS = c }
+            as' <- updateActions xc r str
+            runX xc' $ drawInWin r str
+            eventLoop tv xc' as' signal
+
+         Reposition ->
+            reposWindow cfg
+
+         ChangeScreen -> do
+            ncfg <- updateConfigPosition cfg
+            reposWindow ncfg
+
+         Hide   t -> hide   (t*100*1000)
+         Reveal t -> reveal (t*100*1000)
+         Toggle t -> toggle t
+
+         TogglePersistent -> eventLoop
+            tv xc { config = cfg { persistent = not $ persistent cfg } } as signal
+
+         Action but x -> action but x
+
+    where
+        isPersistent = not $ persistent cfg
+
+        hide t
+            | t == 0 =
+                when isPersistent (hideWindow d w) >> eventLoop tv xc as signal
+            | otherwise = do
+                void $ forkIO
+                     $ threadDelay t >> atomically (putTMVar signal $ Hide 0)
+                eventLoop tv xc as signal
+
+        reveal t
+            | t == 0 = do
+                when isPersistent (showWindow r cfg d w)
+                eventLoop tv xc as signal
+            | otherwise = do
+                void $ forkIO
+                     $ threadDelay t >> atomically (putTMVar signal $ Reveal 0)
+                eventLoop tv xc as signal
+
+        toggle t = do
+            ismapped <- isMapped d w
+            atomically (putTMVar signal $ if ismapped then Hide t else Reveal t)
+            eventLoop tv xc as signal
+
+        reposWindow rcfg = do
+          r' <- repositionWin d w (head fs) rcfg
+          eventLoop tv (XConf d r' w fs vos is rcfg) as signal
+
+        updateConfigPosition ocfg =
+          case position ocfg of
+            OnScreen n o -> do
+              srs <- getScreenInfo d
+              return (if n == length srs
+                       then
+                        (ocfg {position = OnScreen 1 o})
+                       else
+                        (ocfg {position = OnScreen (n+1) o}))
+            o -> return (ocfg {position = OnScreen 1 o})
+
+        action button x = do
+          mapM_ runAction $
+            filter (\(Spawn b _) -> button `elem` b) $
+            concatMap (\(a,_,_) -> a) $
+            filter (\(_, from, to) -> x >= from && x <= to) as
+          eventLoop tv xc as signal
+
+-- $command
+
+-- | Runs a command as an independent thread and returns its Async handles
+-- and the TVar the command will be writing to.
+startCommand :: TMVar SignalType
+             -> (Runnable,String,String)
+             -> IO ([Async ()], TVar String)
+startCommand sig (com,s,ss)
+    | alias com == "" = do var <- atomically $ newTVar is
+                           atomically $ writeTVar var (s ++ ss)
+                           return ([], var)
+    | otherwise = do var <- atomically $ newTVar is
+                     let cb str = atomically $ writeTVar var (s ++ str ++ ss)
+                     a1 <- async $ start com cb
+                     a2 <- async $ trigger com $ maybe (return ())
+                                                 (atomically . putTMVar sig)
+                     return ([a1, a2], var)
+    where is = s ++ "Updating..." ++ ss
+
+updateString :: Config -> TVar [String]
+                -> IO [[(Widget, String, Int, Maybe [Action])]]
+updateString conf v = do
+  s <- readTVarIO v
+  let l:c:r:_ = s ++ repeat ""
+  liftIO $ mapM (parseString conf) [l, c, r]
+
+updateActions :: XConf -> Rectangle -> [[(Widget, String, Int, Maybe [Action])]]
+                 -> IO [([Action], Position, Position)]
+updateActions conf (Rectangle _ _ wid _) ~[left,center,right] = do
+  let (d,fs) = (display &&& fontListS) conf
+      strLn :: [(Widget, String, Int, Maybe [Action])] -> IO [(Maybe [Action], Position, Position)]
+      strLn  = liftIO . mapM getCoords
+      iconW i = maybe 0 Bitmap.width (lookup i $ iconS conf)
+      getCoords (Text s,_,i,a) = textWidth d (fs!!i) s >>= \tw -> return (a, 0, fi tw)
+      getCoords (Icon s,_,_,a) = return (a, 0, fi $ iconW s)
+      partCoord off xs = map (\(a, x, x') -> (fromJust a, x, x')) $
+                         filter (\(a, _,_) -> isJust a) $
+                         scanl (\(_,_,x') (a,_,w') -> (a, x', x' + w'))
+                               (Nothing, 0, off)
+                               xs
+      totSLen = foldr (\(_,_,len) -> (+) len) 0
+      remWidth xs = fi wid - totSLen xs
+      offs = 1
+      offset a xs = case a of
+                     C -> (remWidth xs + offs) `div` 2
+                     R -> remWidth xs
+                     L -> offs
+  fmap concat $ mapM (\(a,xs) ->
+                       (\xs' -> partCoord (offset a xs') xs') <$> strLn xs) $
+                     zip [L,C,R] [left,center,right]
diff --git a/src/lib/Xmobar/Plugins.hs b/src/lib/Xmobar/Plugins.hs
index 75ee306..e8c6403 100644
--- a/src/lib/Xmobar/Plugins.hs
+++ b/src/lib/Xmobar/Plugins.hs
@@ -17,7 +17,6 @@
 module Xmobar.Plugins
     ( Exec (..)
     , tenthSeconds
-    , readFileSafe
     , hGetLineSafe
     ) where
 
diff --git a/src/lib/Xmobar/Types.hs b/src/lib/Xmobar/Types.hs
new file mode 100644
index 0000000..f7c4fdf
--- /dev/null
+++ b/src/lib/Xmobar/Types.hs
@@ -0,0 +1,47 @@
+------------------------------------------------------------------------------
+-- |
+-- Module: Xmobar.Types
+-- Copyright: (c) 2018 Jose Antonio Ortega Ruiz
+-- License: BSD3-style (see LICENSE)
+--
+-- Maintainer: jao@gnu.org
+-- Stability: unstable
+-- Portability: portable
+-- Created: Sat Nov 24, 2018 19:02
+--
+--
+-- The Xmobar basic type
+--
+------------------------------------------------------------------------------
+
+
+module Xmobar.Types (X , XConf (..), runX) where
+
+import Graphics.X11.Xlib
+import Control.Monad.Reader
+import Data.Map
+
+import Xmobar.Config
+import Xmobar.Bitmap
+import Xmobar.XUtil
+
+
+-- The Xmobar data type and basic loops and functions.
+
+-- | The X type is a ReaderT
+type X = ReaderT XConf IO
+
+-- | The ReaderT inner component
+data XConf =
+    XConf { display   :: Display
+          , rect      :: Rectangle
+          , window    :: Window
+          , fontListS :: [XFont]
+          , verticalOffsets :: [Int]
+          , iconS     :: Map FilePath Bitmap
+          , config    :: Config
+          }
+
+-- | Runs the ReaderT
+runX :: XConf -> X () -> IO ()
+runX xc f = runReaderT f xc
diff --git a/src/lib/Xmobar/XUtil.hs b/src/lib/Xmobar/XUtil.hs
index 5093e59..536a2fb 100644
--- a/src/lib/Xmobar/XUtil.hs
+++ b/src/lib/Xmobar/XUtil.hs
@@ -22,7 +22,6 @@ module Xmobar.XUtil
     , textWidth
     , printString
     , nextEvent'
-    , readFileSafe
     , hGetLineSafe
     ) where
 
@@ -40,7 +39,7 @@ import System.Posix.Types (Fd(..))
 import System.IO
 
 #if defined XFT || defined UTF8
-import qualified System.IO as S (readFile,hGetLine)
+import qualified System.IO as S (hGetLine)
 #endif
 
 #if defined XFT
@@ -50,13 +49,6 @@ import Graphics.X11.Xrender
 
 import Xmobar.ColorCache
 
-readFileSafe :: FilePath -> IO String
-#if defined XFT || defined UTF8
-readFileSafe = S.readFile
-#else
-readFileSafe = readFile
-#endif
-
 hGetLineSafe :: Handle -> IO String
 #if defined XFT || defined UTF8
 hGetLineSafe = S.hGetLine
diff --git a/xmobar.cabal b/xmobar.cabal
index 4a22a8b..9c6fcf7 100644
--- a/xmobar.cabal
+++ b/xmobar.cabal
@@ -95,19 +95,12 @@ library
     hs-source-dirs:  src/lib
 
     exposed-modules: Xmobar,
+                     Xmobar.Types,
+                     Xmobar.Config,
                      Xmobar.Actions,
                      Xmobar.Bitmap,
-                     Xmobar.Config,
-                     Xmobar.Parsers,
                      Xmobar.Commands,
-                     Xmobar.Localize,
-                     Xmobar.XUtil,
-                     Xmobar.StatFS,
                      Xmobar.Runnable,
-                     Xmobar.ColorCache,
-                     Xmobar.Window,
-                     Xmobar.Signal,
-                     Xmobar.Environment,
                      Xmobar.Plugins,
                      Xmobar.Plugins.BufferedPipeReader,
                      Xmobar.Plugins.CommandReader,
@@ -139,6 +132,17 @@ library
                      Xmobar.Plugins.Monitors.Bright,
                      Xmobar.Plugins.Monitors.CatInt
 
+    other-modules: Xmobar.Localize,
+                   Xmobar.Parsers,
+                   Xmobar.XUtil,
+                   Xmobar.StatFS,
+                   Xmobar.ColorCache,
+                   Xmobar.Window,
+                   Xmobar.Draw,
+                   Xmobar.Signal,
+                   Xmobar.Environment,
+                   Xmobar.EventLoop
+
     extra-libraries: Xrandr Xrender
 
     ghc-options: -funbox-strict-fields -Wall -fno-warn-unused-do-bind
@@ -297,6 +301,8 @@ test-suite XmobarTest
   other-modules: Plugins.Monitors.CommonSpec,
                  Xmobar.Commands,
                  Xmobar.Signal,
+                 Xmobar.XUtil,
+                 Xmobar.ColorCache,
                  Xmobar.Plugins,
                  Xmobar.Plugins.Utils,
                  Xmobar.Plugins.Monitors.Common