diff --git a/LICENSE b/LICENSE
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--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,20 @@
+Copyright (c) 2016 Brian W Bush
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be included
+in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
diff --git a/ReadMe.md b/ReadMe.md
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--- /dev/null
+++ b/ReadMe.md
@@ -0,0 +1,14 @@
+Linux joystick events via a Kafka message broker
+================================================
+
+This package contains functions for passing [Linux joystick](https://www.kernel.org/doc/Documentation/input/joystick-api.txt) events to topics on a [Kafka message broker](https://kafka.apache.org/).
+
+
+Clients
+-------
+
+The simple Kafka client that produces events from the joystick can be run, for example, as follows:
+
+ cabal run kafka-device-joystick -- /dev/input/js0 joystick-client localhost 9092 events joystick
+
+Also see https://hackage.haskell.org/package/kafka-device/.
diff --git a/Setup.hs b/Setup.hs
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--- /dev/null
+++ b/Setup.hs
@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain
diff --git a/kafka-device-joystick.cabal b/kafka-device-joystick.cabal
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--- /dev/null
+++ b/kafka-device-joystick.cabal
@@ -0,0 +1,49 @@
+name: kafka-device-joystick
+version: 0.1.5.0
+synopsis: Linux joystick events via a Kafka message broker
+description: This package contains functions for passing Linux joystick events to topics on a Kafka message broker \<\>. The joystick's driver must conform to the Linux Joystick API \<\>. Also see \<\>.
+license: MIT
+license-file: LICENSE
+author: Brian W Bush
+maintainer: Brian W Bush
+copyright: (c) 2016 Brian W Bush
+category: Hardware
+build-type: Simple
+cabal-version: >= 1.10
+stability: Experimental
+homepage: https://bitbucket.org/functionally/kafka-device-joystick
+bug-reports: https://bwbush.atlassian.net/projects/HKAFDEV/issues/
+package-url: https://bitbucket.org/functionally/kafka-device-joystick/downloads/kafka-device-joystick-0.1.5.0.tar.gz
+
+extra-source-files: ReadMe.md
+
+source-repository head
+ type: git
+ location: https://bitbucket.org/functionally/kafka-device-joystick
+
+library
+ exposed-modules: Network.UI.Kafka.Joystick
+ System.Hardware.Linux.Joystick
+ build-depends: base >= 4.8 && < 5
+ , aeson
+ , binary
+ , bytestring
+ , cereal
+ , kafka-device
+ , milena
+ hs-source-dirs: src
+ ghc-options: -Wall
+ default-language: Haskell2010
+
+executable kafka-device-joystick
+ main-is: Main.hs
+ build-depends: base
+ , aeson
+ , binary
+ , bytestring
+ , cereal
+ , kafka-device
+ , milena
+ hs-source-dirs: src
+ ghc-options: -Wall
+ default-language: Haskell2010
diff --git a/src/Main.hs b/src/Main.hs
new file mode 100644
--- /dev/null
+++ b/src/Main.hs
@@ -0,0 +1,46 @@
+{-|
+Module : Main
+Copyright : (c) 2016 Brian W Bush
+License : MIT
+Maintainer : Brian W Bush
+Stability : Experimental
+Portability : Linux
+
+Produce events for a Kafka topic from a Linux joystick.
+-}
+
+
+module Main (
+-- * Main entry
+ main
+) where
+
+
+import Data.String (IsString(fromString))
+import Network.UI.Kafka.Joystick (joystickLoop)
+import System.Environment (getArgs)
+
+
+-- The main action.
+main :: IO ()
+main =
+ do
+ args <- getArgs
+ case args of
+ [device, client, host, port, topic, sensor] ->
+ do
+ putStrLn $ "Device: " ++ device
+ putStrLn $ "Kafka client: " ++ client
+ putStrLn $ "Kafka address: (" ++ host ++ "," ++ port ++ ")"
+ putStrLn $ "Kafka topic: " ++ topic
+ putStrLn $ "Sensor name: " ++ sensor
+ (_, loop) <-
+ joystickLoop
+ device
+ (fromString client)
+ (fromString host, toEnum $ read port)
+ (fromString topic)
+ sensor
+ result <- loop
+ either print return result
+ _ -> putStrLn "USAGE: kafka-device-joystick device client host port topic sensor"
diff --git a/src/Network/UI/Kafka/Joystick.hs b/src/Network/UI/Kafka/Joystick.hs
new file mode 100644
--- /dev/null
+++ b/src/Network/UI/Kafka/Joystick.hs
@@ -0,0 +1,71 @@
+{-|
+Module : Network.UI.Kafka.Joystick
+Copyright : (c) 2016 Brian W Bush
+License : MIT
+Maintainer : Brian W Bush
+Stability : Experimental
+Portability : Linux
+
+Produce events for a Kafka topic from a Linux joystick, which must conform to the Linux Joystick API \<\>.
+-}
+
+
+{-# LANGUAGE RecordWildCards #-}
+
+
+module Network.UI.Kafka.Joystick (
+-- * Event handling
+ joystickLoop
+) where
+
+
+import Control.Monad (guard)
+import Data.ByteString.Lazy.Char8 (hGet)
+import Data.Maybe (catMaybes)
+import Network.Kafka (KafkaAddress, KafkaClientId)
+import Network.Kafka.Protocol (TopicName)
+import Network.UI.Kafka (ExitAction, LoopAction, Sensor, producerLoop)
+import Network.UI.Kafka.Types (Button(..), Event(..), Toggle(..))
+import System.Hardware.Linux.Joystick (Joystick(..), byteLength, interpretJoystick, maxValue)
+import System.IO (IOMode(ReadMode), hClose, openFile)
+
+
+-- | Produce events for a Kafka topic from a Linux Joystick.
+joystickLoop :: FilePath -- ^ The path to the joystick device, e.g. "\/dev\/input\/js0".
+ -> KafkaClientId -- ^ A Kafka client identifier for the producer.
+ -> KafkaAddress -- ^ The address of the Kafka broker.
+ -> TopicName -- ^ The Kafka topic name.
+ -> Sensor -- ^ The name of the sensor producing events.
+ -> IO (ExitAction, LoopAction) -- ^ Action to create the exit and loop actions.
+joystickLoop path client address topic sensor =
+ do
+ joystick <- openFile path ReadMode
+ (exit, loop) <-
+ producerLoop client address topic sensor
+ $ translate
+ . interpretJoystick
+ <$> hGet joystick byteLength
+ return
+ (
+ do
+ exit
+ hClose joystick
+ , loop
+ )
+
+
+-- | Translate a Linux Joystick event into events for Kafka.
+translate :: Joystick -- ^ The joystick event.
+ -> [Event] -- ^ The corresponding events for Kafka.
+translate Joystick{..} =
+ catMaybes
+ [
+ do
+ guard button
+ return
+ $ ButtonEvent (IndexButton number, if value == 0 then Up else Down)
+ , do
+ guard axis
+ return
+ $ AnalogEvent number (fromIntegral value / fromIntegral maxValue)
+ ]
diff --git a/src/System/Hardware/Linux/Joystick.hs b/src/System/Hardware/Linux/Joystick.hs
new file mode 100644
--- /dev/null
+++ b/src/System/Hardware/Linux/Joystick.hs
@@ -0,0 +1,149 @@
+{-|
+Module : System.Hardware.Linux.Joystick
+Copyright : (c) 2016 Brian W Bush
+License : MIT
+Maintainer : Brian W Bush
+Stability : Experimental
+Portability : Linux
+
+Interpret events from a Linux joystick, which must conform to the Linux Joystick API \<\>.
+-}
+
+
+{-# LANGUAGE DeriveGeneric #-}
+{-# LANGUAGE RecordWildCards #-}
+
+
+module System.Hardware.Linux.Joystick (
+-- * Types and values
+ Joystick(..)
+, minValue
+, maxValue
+, byteLength
+-- * Event handling
+, interpretJoystick
+, readJoystick
+) where
+
+
+import Data.Aeson.Types (FromJSON, ToJSON)
+import Data.Binary (Binary(..), decode, encode)
+import Data.Binary.Get (getWord16host, getWord32host)
+import Data.Binary.Put (putWord16host, putWord32host)
+import Data.Bits ((.&.), complement, shift)
+import Data.ByteString.Lazy.Char8 as BS (ByteString, length, readFile, splitAt)
+import Data.Serialize (Serialize)
+import Data.Word (Word8, Word16, Word32)
+import GHC.Generics (Generic)
+
+
+-- | The minimum for 'value'.
+minValue :: Int
+minValue = - maxValue
+
+
+-- | The maximum for 'value'.
+maxValue :: Int
+maxValue = 1 `shift` 15 - 1
+
+
+-- | The number of bytes in a joystick event.
+byteLength :: Integral a => a
+byteLength =
+ fromIntegral
+ . BS.length
+ . encode
+ $ RawJoystick 0 0 0 0
+
+
+
+data RawJoystick =
+ RawJoystick
+ {
+ rawTime :: Word32
+ , rawValue :: Word16
+ , rawType :: Word8
+ , rawNumber :: Word8
+ }
+ deriving (Eq, Ord, Read, Show)
+
+instance Binary RawJoystick where
+ get =
+ do
+ rawTime <- getWord32host
+ rawValue <- getWord16host
+ rawType <- get
+ rawNumber <- get
+ return RawJoystick{..}
+ put RawJoystick{..} =
+ do
+ putWord32host rawTime
+ putWord16host rawValue
+ put rawType
+ put rawNumber
+
+
+-- | Joystick data. See \<\> for details.
+data Joystick =
+ Joystick
+ {
+ timestamp :: Int -- ^ The event timestamp in milliseconds.
+ , value :: Int -- ^ The data value.
+ , number :: Int -- ^ The button or axis number.
+ , button :: Bool -- ^ Whether the button is being reported.
+ , axis :: Bool -- ^ Whether the axis is being reported.
+ , initial :: Bool -- ^ Whether the initial value is being reported.
+ }
+ deriving (Eq, Generic, Ord, Read, Show)
+
+instance FromJSON Joystick
+
+instance ToJSON Joystick
+
+instance Binary Joystick
+
+instance Serialize Joystick
+
+
+-- | Interpret Linux Joystick bytes accoding to \<\>.
+interpretJoystick :: ByteString -- ^ The eight bytes.
+ -> Joystick -- ^ The corresponding joystick data.
+interpretJoystick x =
+ let
+ RawJoystick{..} = decode x
+ timestamp = fromIntegral rawTime
+ value = twosComplement rawValue
+ number = fromIntegral rawNumber
+ typ = fromIntegral rawType :: Int
+ button = 0x01 .&. typ /= 0
+ axis = 0x02 .&. typ /= 0
+ initial = 0x80 .&. typ /= 0
+ in
+ Joystick{..}
+
+
+-- | Decode a two's complement.
+twosComplement :: Word16 -- ^ The two's complement.
+ -> Int -- ^ The corresponding integer.
+twosComplement x =
+ fromIntegral (x' .&. complement mask) - fromIntegral (x' .&. mask)
+ where
+ x' = fromIntegral x :: Int
+ mask = 1 `shift` 15
+
+
+-- | Read a stream of joystick data.
+readJoystick :: FilePath -- ^ The joystick device, e.g., "\/dev\/input\/js0".
+ -> IO [Joystick] -- ^ Action to read the joystick data.
+readJoystick path =
+ let
+ chunks :: ByteString -> [ByteString]
+ chunks x =
+ let
+ (y, ys) = BS.splitAt 8 x
+ in
+ y : chunks ys
+ in
+ map interpretJoystick
+ . chunks
+ <$> BS.readFile path