sscan-0.2: Main.hs
{-
sscan --- text UI for scanning with SANE
Copyright (C) 2017 Sean Whitton
This file is part of sscan.
sscan is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
sscan is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with sscan. If not, see <http://www.gnu.org/licenses/>.
-}
{-# LANGUAGE OverloadedStrings #-}
import Control.Concurrent.Async (concurrently_)
import Control.Monad (unless, void, when)
import Data.Time.Clock.POSIX (getPOSIXTime, posixSecondsToUTCTime)
import Data.Time.Format (defaultTimeLocale, formatTime,
iso8601DateFormat)
import Lens.Micro ((^.))
import System.Directory (getHomeDirectory, removeFile,
renamePath, withCurrentDirectory)
import System.Exit (ExitCode (..))
import System.FilePath ((<.>), (</>))
import System.IO (IOMode (WriteMode), hClose,
hGetContents, hPutStr, openFile,
withBinaryFile, withFile)
import System.IO.Temp (withSystemTempDirectory)
import System.Process
import Types.State
import UI
processScanSessDir :: St -> FilePath -> IO ()
processScanSessDir st dir = withCurrentDirectory dir $ do
posix <- getPOSIXTime
let stamp = show (round posix :: Int)
logH <- openFile (logFile stamp) WriteMode -- TODO maybe AppendMode?
void $ case st^.stOutFormat of
PDF -> do
-- 1. convert tiff->PDF
void $ createProcessWait_ "convert"
(proc "convert" (allPages ++ ["temp.pdf"]))
-- 2. set metadata with pdftk
renamePath (dir </> "temp.pdf") (dir </> "temp2.pdf")
writeFile "metadata" (metadata posix)
void $ createProcessWait_ "pdftk"
(proc "pdftk"
["temp2.pdf", "update_info", "metadata", "output", "temp.pdf"])
{ std_in = NoStream
, std_out = NoStream
, std_err = UseHandle logH
}
-- 3. maybe ocrmypdf
when (st^.stOCR) $ do
renamePath (dir </> "temp.pdf") (dir </> "temp2.pdf")
-- OCRmyPDF dies if stdout is not connected, so tell it
-- to output to stdout
withBinaryFile "temp.pdf" WriteMode $ \tempFile -> do
(_, _, Just herr, p) <- createProcess_ "OCRmyPDF"
-- we'd like to use --remove-background here, but then
-- qpdf says that ocrmypdf's output is damaged.
-- reported upstream
(proc "ocrmypdf" ["-c", "-i", "-r", "temp2.pdf", "-"])
{ std_in = NoStream
, std_out = UseHandle tempFile
, std_err = CreatePipe
}
-- OCRmyPDF does not yet have a --quiet option, so we
-- emulate the chronic(1) utility
exitCode <- waitForProcess p
unless (exitCode == ExitSuccess) $
hGetContents herr >>= hPutStr logH
hClose herr
-- 4. qpdf (ocrmypdf invokes qpdf but it doesn't use
-- --linearize, which shrinks the PDF, often substantially)
void $ createProcessWait_ "qpdf"
(proc "qpdf" ["--linearize", "temp.pdf", outFile stamp])
{ std_in = NoStream
, std_out = NoStream
, std_err = UseHandle logH
}
-- assume that only one page was scanned. Not clear how we
-- can avoid this assumption when producing a PNG
PNG -> void $ createProcessWait_ "convert"
(proc "convert" ["page1" <.> "tiff", outFile stamp])
{ std_in = NoStream
, std_out = NoStream
, std_err = UseHandle logH
}
hClose logH
-- clean up the log file if it's empty
finalLog <- readFile (logFile stamp)
when (null finalLog) $ removeFile (logFile stamp)
where
logFile stamp = (st^.stOutdir) </> stamp <.> "log"
outFile stamp = (st^.stOutdir) </> stamp <.> outExt
outExt = case st^.stOutFormat of
PDF -> "pdf"
PNG -> "png"
allPages = map (\n -> "page" ++ show n <.> "tiff") [1..(getLatestPage st)]
metadata posix = let date = formatTime
defaultTimeLocale
(iso8601DateFormat Nothing)
(posixSecondsToUTCTime posix)
in unlines [ "InfoBegin"
, "InfoKey: Title"
, "InfoValue: scan of " ++ date
]
makeInitialState :: IO St
makeInitialState = do
home <- getHomeDirectory
papersize <- init <$> readFile "/etc/papersize"
let paper = if papersize == "letter" then Letter else A4
return St
{ _stScanSess = Nothing
, _stOCR = True
, _stColour = Greyscale
, _stPaper = paper
, _stDefaultPaper = paper
, _stDPI = 300
, _stOutFormat = PDF
, _stOutdir = home </> "tmp"
}
scanPage :: St -> FilePath -> IO Bool
scanPage st dir = withFile outF WriteMode $ \outH -> do
exit <- createProcessWait_ "scanimage" (proc "scanimage" (scanimageArgs st))
{ std_in = NoStream
, std_out = UseHandle outH
, std_err = Inherit -- let the user see progress bar
}
case exit of
ExitSuccess -> return True
ExitFailure c -> do
putStrLn $ "scanimage exited with exit code " ++ show c ++ "!"
putStrLn "This might because sscan tried to use an option that your"
putStrLn "scanner does not support. Please try another preset."
putStrLn "Press any key to abort this scanning session..."
void getChar
return False
where
outF = dir </> "page" ++ (show $ getLatestPage st + 1) <.> "tiff"
scanimageArgs :: St -> [String]
scanimageArgs st =
[ "-vp"
, "--format=tiff"
, "--resolution=" ++ show (st^.stDPI)
, "--mode=" ++ case st^.stColour of
Colour -> "Color"
Greyscale -> "Gray"
Lineart -> "Lineart"
] ++ case st^.stPaper of
Auto -> ["--swcrop=yes"]
_ -> [ "-x"
, show $ case st^.stPaper of
A4 -> 210 :: Double
Letter -> 215.9 :: Double
Photo -> 150 :: Double
Auto -> 1 :: Double
, "-y"
, show $ case st^.stPaper of
A4 -> 297 :: Double
Letter -> 279.4 :: Double
Photo -> 100 :: Double
Auto -> 1 :: Double
]
-- other device-specific scanimage options the old script supported:
-- --swdespeck; --color-filter; --depth
-- TODO include usbreset.c as a cbit, and use FFI to optionally reset
-- the scanner's USB connection after a scan -- this is needed on some
-- scanners that I occasionally use
processCommand :: St -> IO ()
processCommand st = case st^.stScanSess of
Nothing -> putStrLn "Waiting for OCR threads to complete..."
>> return () -- quit sscan
Just (ScanSess command _ maybeDir) -> case maybeDir of
Nothing -> withSystemTempDirectory "sscan" $ \dir ->
processCommand (setScanSessDir dir st)
Just dir -> case command of
Abort -> newSession
NextPage -> scanPage st dir >>= \scanned ->
if scanned
then presentUI (incrementPages st)
else newSession
FinalPage -> scanPage st dir
>> finaliseSession (incrementPages st) dir
Finalise -> finaliseSession st dir
where
newSession = presentUI $ resetScanSess st
finaliseSession st' dir =
concurrently_ (processScanSessDir st' dir) newSession
presentUI :: St -> IO ()
presentUI st = runTheApp st >>= processCommand
main :: IO ()
main = makeInitialState >>= presentUI
-- | Create a process, wait for it to finish, don't close any
-- handles used by the CreateProcess record
createProcessWait_ :: String -> CreateProcess -> IO ExitCode
createProcessWait_ s c = do
(_, _, _, p) <- createProcess_ s c
waitForProcess p