Make inotify optional.

posix/Reanimate/FileWatch.hs

@@ -0,0 +1,18 @@
+module Reanimate.FileWatch
+  ( watchFile ) where
+
+import Control.Concurrent
+import           System.Directory
+
+watchFile :: FilePath -> IO () -> IO ()
+watchFile path handler = do
+    t0 <- getModificationTime path
+    forkIO $ loop t0
+    return ()
+  where
+    loop lastModTime = do
+      t1 <- getModificationTime path
+      if t1 /= lastModTime
+        then handler >> loop t1
+        else threadDelay (10^3 * delay) >> loop lastModTime
+    delay = 1000 -- pool delay in ms.

reanimate.cabal

@@ -32,6 +32,10 @@ Source-Repository head
     Type:      git
     Location:  git://github.com/lemmih/reanimate.git
 
+Flag inotify
+  Description: Enable file watching using linux's inotify
+  Default:     True
+
 library
   hs-source-dirs:     src
   default-language:   Haskell2010
@@ -48,14 +52,21 @@ library
                       Reanimate.Misc
   other-modules:      Reanimate.Svg.NamedColors
                       Reanimate.Cache
+                      Reanimate.FileWatch
                       Paths_reanimate
   build-depends:       base >=4.10 && <4.13,
                        time, text, unix, filepath, process, directory,
                        containers, reanimate-svg >= 0.7.0.0, xml, bytestring, lens, linear, mtl, matrix,
                        JuicyPixels, attoparsec, parallel, diagrams, diagrams-svg,
                        diagrams-core, diagrams-lib, diagrams-contrib,
-                       svg-builder, matrices, cubicbezier, palette, hinotify, websockets,
+                       svg-builder, matrices, cubicbezier, palette, websockets,
                        hashable
+  if flag(inotify)
+    hs-source-dirs:    unix
+    build-depends:     hinotify
+  else
+    hs-source-dirs:    posix
+
 
 Flag server
   Description: Enable rendering server

src/Reanimate/Driver.hs

@@ -7,7 +7,7 @@ import qualified Data.Text          as T
 import           Network.WebSockets
 import           System.Directory   (findFile, listDirectory)
 import           System.Environment (getArgs, getProgName)
-import           System.INotify     (EventVariety (..), addWatch, withINotify)
+import           Reanimate.FileWatch (watchFile)
 import           System.IO          (BufferMode (..), hPutStrLn, hSetBuffering,
                                      stderr, stdin)
 
@@ -38,7 +38,7 @@ reanimate animation = do
         case mbSelf of
           Nothing -> do
             hPutStrLn stderr "Failed to find own source code."
-          Just self -> withINotify $ \notify -> do
+          Just self -> do
             conn <- acceptRequest pending
             slave <- newEmptyMVar
             let handler = modifyMVar_ slave $ \tid -> do
@@ -66,7 +66,7 @@ reanimate animation = do
                               loop (frame : acc)
                   return tid
             putStrLn "Found self. Listening."
-            addWatch notify [Modify] self (const handler)
+            watchFile self handler
             putMVar slave =<< forkIO (return ())
             let loop = do
                   fps <- receiveData conn :: IO T.Text

unix/Reanimate/FileWatch.hs

@@ -0,0 +1,10 @@
+module Reanimate.FileWatch
+  ( watchFile ) where
+
+import           System.INotify
+
+watchFile :: FilePath -> IO () -> IO ()
+watchFile path handler = do
+  notify <- initINotify
+  addWatch notify [Modify] path (const handler)
+  return ()