patat-0.9.0.0: lib/Patat/Main.hs
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{-# LANGUAGE GeneralizedNewtypeDeriving #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE RecordWildCards #-}
module Patat.Main
( main
) where
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import Control.Concurrent (forkIO, killThread,
threadDelay)
import Control.Concurrent.Chan (Chan)
import qualified Control.Concurrent.Chan as Chan
import Control.Exception (bracket)
import Control.Monad (forever, unless, when)
import qualified Data.Aeson.Extended as A
import Data.Foldable (for_)
import Data.Functor (($>))
import Data.Time (UTCTime)
import Data.Version (showVersion)
import qualified Options.Applicative as OA
import qualified Options.Applicative.Help.Pretty as OA.PP
import Patat.AutoAdvance
import qualified Patat.Images as Images
import Patat.Presentation
import qualified Patat.Presentation.SpeakerNotes as SpeakerNotes
import qualified Patat.PrettyPrint as PP
import qualified Paths_patat
import Prelude
import qualified System.Console.ANSI as Ansi
import System.Directory (doesFileExist,
getModificationTime)
import System.Exit (exitFailure, exitSuccess)
import qualified System.IO as IO
import qualified Text.Pandoc as Pandoc
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data Options = Options
{ oFilePath :: !(Maybe FilePath)
, oForce :: !Bool
, oDump :: !Bool
, oWatch :: !Bool
, oVersion :: !Bool
} deriving (Show)
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parseOptions :: OA.Parser Options
parseOptions = Options
<$> (OA.optional $ OA.strArgument $
OA.metavar "FILENAME" <>
OA.help "Input file")
<*> (OA.switch $
OA.long "force" <>
OA.short 'f' <>
OA.help "Force ANSI terminal" <>
OA.hidden)
<*> (OA.switch $
OA.long "dump" <>
OA.short 'd' <>
OA.help "Just dump all slides and exit" <>
OA.hidden)
<*> (OA.switch $
OA.long "watch" <>
OA.short 'w' <>
OA.help "Watch file for changes")
<*> (OA.switch $
OA.long "version" <>
OA.help "Display version info and exit" <>
OA.hidden)
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parserInfo :: OA.ParserInfo Options
parserInfo = OA.info (OA.helper <*> parseOptions) $
OA.fullDesc <>
OA.header ("patat v" <> showVersion Paths_patat.version) <>
OA.progDescDoc (Just desc)
where
desc = OA.PP.vcat
[ "Terminal-based presentations using Pandoc"
, ""
, "Controls:"
, "- Next slide: space, enter, l, right, pagedown"
, "- Previous slide: backspace, h, left, pageup"
, "- Go forward 10 slides: j, down"
, "- Go backward 10 slides: k, up"
, "- First slide: 0"
, "- Last slide: G"
, "- Jump to slide N: N followed by enter"
, "- Reload file: r"
, "- Quit: q"
]
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parserPrefs :: OA.ParserPrefs
parserPrefs = OA.prefs OA.showHelpOnError
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errorAndExit :: [String] -> IO a
errorAndExit msg = do
mapM_ (IO.hPutStrLn IO.stderr) msg
exitFailure
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assertAnsiFeatures :: IO ()
assertAnsiFeatures = do
supports <- Ansi.hSupportsANSI IO.stdout
unless supports $ errorAndExit
[ "It looks like your terminal does not support ANSI codes."
, "If you still want to run the presentation, use `--force`."
]
--------------------------------------------------------------------------------
main :: IO ()
main = do
options <- OA.customExecParser parserPrefs parserInfo
when (oVersion options) $ do
putStrLn $ showVersion Paths_patat.version
putStrLn $ "Using pandoc: " ++ showVersion Pandoc.pandocVersion
exitSuccess
filePath <- case oFilePath options of
Just fp -> return fp
Nothing -> OA.handleParseResult $ OA.Failure $
OA.parserFailure parserPrefs parserInfo
(OA.ShowHelpText Nothing) mempty
errOrPres <- readPresentation filePath
pres <- either (errorAndExit . return) return errOrPres
unless (oForce options) assertAnsiFeatures
-- (Maybe) initialize images backend.
images <- traverse Images.new $ psImages $ pSettings pres
-- (Maybe) initialize speaker notes.
withMaybeHandle SpeakerNotes.with
(psSpeakerNotes $ pSettings pres) $ \speakerNotes ->
if oDump options
then dumpPresentation pres
else interactiveLoop options images speakerNotes pres
where
interactiveLoop
:: Options -> Maybe Images.Handle -> Maybe SpeakerNotes.Handle
-> Presentation -> IO ()
interactiveLoop options images speakerNotes pres0 =
interactively readPresentationCommand $ \commandChan0 -> do
-- If an auto delay is set, use 'autoAdvance' to create a new one.
commandChan <- case psAutoAdvanceDelay (pSettings pres0) of
Nothing -> return commandChan0
Just (A.FlexibleNum delay) -> autoAdvance delay commandChan0
-- Spawn a thread that adds 'Reload' commands based on the file time.
mtime0 <- getModificationTime (pFilePath pres0)
when (oWatch options) $ do
_ <- forkIO $ watcher commandChan (pFilePath pres0) mtime0
return ()
let loop :: Presentation -> Maybe String -> IO ()
loop pres mbError = do
for_ speakerNotes $ \sn ->
SpeakerNotes.write sn $ activeSpeakerNotes pres
size <- getDisplaySize pres
let display = case mbError of
Nothing -> displayPresentation size pres
Just err -> DisplayDoc $
displayPresentationError size pres err
Ansi.clearScreen
Ansi.setCursorPosition 0 0
cleanup <- case display of
DisplayDoc doc -> PP.putDoc doc $> mempty
DisplayImage path -> case images of
Nothing -> do
PP.putDoc $ displayPresentationError
size pres "image backend not initialized"
pure mempty
Just img -> do
putStrLn ""
IO.hFlush IO.stdout
Images.drawImage img path
c <- Chan.readChan commandChan
update <- updatePresentation c pres
cleanup
case update of
ExitedPresentation -> return ()
UpdatedPresentation pres' -> loop pres' Nothing
ErroredPresentation err -> loop pres (Just err)
loop pres0 Nothing
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-- | Utility for dealing with pecularities of stdin & interactive applications
-- on the terminal. Tries to restore the original state of the terminal as much
-- as possible.
interactively
:: (IO.Handle -> IO a)
-- ^ Reads a command from stdin (or from some other IO). This will be
-- interrupted by 'killThread' when the application finishes.
-> (Chan a -> IO ())
-- ^ Application to run.
-> IO ()
-- ^ Returns when application finishes.
interactively reader app = bracket setup teardown $ \(_, _, _, chan) -> app chan
where
setup = do
chan <- Chan.newChan
echo <- IO.hGetEcho IO.stdin
buff <- IO.hGetBuffering IO.stdin
IO.hSetEcho IO.stdin False
IO.hSetBuffering IO.stdin IO.NoBuffering
Ansi.hideCursor
readerThreadId <- forkIO $ forever $
reader IO.stdin >>= Chan.writeChan chan
return (echo, buff, readerThreadId, chan)
teardown (echo, buff, readerThreadId, _chan) = do
Ansi.showCursor
Ansi.clearScreen
Ansi.setCursorPosition 0 0
killThread readerThreadId
IO.hSetEcho IO.stdin echo
IO.hSetBuffering IO.stdin buff
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watcher :: Chan.Chan PresentationCommand -> FilePath -> UTCTime -> IO a
watcher chan filePath mtime0 = do
-- The extra exists check helps because some editors temporarily make the
-- file disappear while writing.
exists <- doesFileExist filePath
mtime1 <- if exists then getModificationTime filePath else return mtime0
when (mtime1 > mtime0) $ Chan.writeChan chan Reload
threadDelay (200 * 1000)
watcher chan filePath mtime1
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-- | Wrapper for optional handles.
withMaybeHandle
:: (settings -> (handle -> IO a) -> IO a)
-> Maybe settings
-> (Maybe handle -> IO a)
-> IO a
withMaybeHandle _ Nothing f = f Nothing
withMaybeHandle impl (Just settings) f = impl settings (f . Just)