Run.EventLoop

1 files changed, 252 insertions, 0 deletions

diff --git a/src/lib/Xmobar/Run/EventLoop.hs b/src/lib/Xmobar/Run/EventLoop.hs
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+{-# LANGUAGE CPP #-}
+
+------------------------------------------------------------------------------
+-- |
+-- Module: Xmobar.X11.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.Run.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.Config
+import Xmobar.Actions
+import Xmobar.Utils
+import Xmobar.System.Signal
+import Xmobar.Run.Commands
+import Xmobar.Run.Runnable
+import Xmobar.X11.Parsers
+import Xmobar.X11.Window
+import Xmobar.X11.XUtil
+import Xmobar.X11.Draw
+import Xmobar.X11.Bitmap as Bitmap
+import Xmobar.X11.Types
+
+#ifdef XFT
+import Graphics.X11.Xft
+#endif
+
+#ifdef DBUS
+import Xmobar.System.DBus
+#endif
+
+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
+
+         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]