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{-
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 TemplateHaskell #-}
module Types.State where
import Data.Maybe
import Lens.Micro ((&), (.~), (^.))
import Lens.Micro.TH (makeLenses)
-- | Whether to do colour, grey or b&w scans
data Colour = Lineart | Greyscale | Colour
deriving (Eq, Show)
cycleColour :: Colour -> Colour
cycleColour Lineart = Greyscale
cycleColour Greyscale = Colour
cycleColour Colour = Lineart
-- | Paper size to scan (determines both scanning area and PDF page
-- size)
data Paper = A4 | Letter | Photo | Auto
deriving (Eq, Show)
cyclePaper :: Paper -> Paper
cyclePaper A4 = Letter
cyclePaper Letter = Photo
cyclePaper Photo = Auto
cyclePaper Auto = A4
-- | DPI to scan
type DPI = Int
-- | Output format
data OutputFormat = PDF | PNG
deriving (Eq, Show)
-- | An active scanning session
data ScanSess = ScanSess
-- | An action requested by the user, that has not yet been
-- fulfilled
Command
-- | The number of pages scanned so far in this scanning session
Int
-- | Temporary directory containing pages scanned in this scanning
-- session, if any have been scanned, and the session is multi-page
(Maybe FilePath)
-- | An sscan operation selected by the user in the UI
data Command
-- | Scan an additional page, or the first page, of a multi-page
-- scanning session.
= NextPage
-- | Scan the final page of a multi-page scanning session, or the
-- first page of a single-page scanning session
| FinalPage
-- | End a multi-page scanning session without scanning anymore
-- pages, i.e., consider the most recently scanned page the final
-- page
| Finalise
-- | Abandon the current scanning session. Delete its tmpdir.
| Abort
-- | Application state
data St =
--
St { _stScanSess :: Maybe ScanSess -- ^ Nothing indicates user
-- wants to quit sscan
, _stOCR :: Bool -- ^ whether to use OCRmyPDF
, _stColour :: Colour
, _stPaper :: Paper -- ^ currently selected paper size
, _stDefaultPaper :: Paper -- ^ locale's default paper size
, _stDPI :: DPI
, _stOutFormat :: OutputFormat
, _stOutdir :: FilePath -- ^ where to save final PDFs
}
makeLenses ''St
ifScanSess :: St -> a -> a -> a
ifScanSess st a b = if isJust $ st^.stScanSess then a else b
-- | Update a state when there is no scanning session in progress (the
-- state should not be changed when some pages have already been
-- scanned)
updateSt :: St -> (St -> St) -> St
updateSt st f = ifScanSess st st (f st)
resetScanSess :: St -> St
resetScanSess st = st & stScanSess .~ Nothing
setScanSessDir :: FilePath -> St -> St
setScanSessDir dir st = case st^.stScanSess of
Nothing -> st
Just (ScanSess c p _) ->
st & stScanSess .~ (Just $ ScanSess c p (Just dir))
incrementPages :: St -> St
incrementPages st = case st^.stScanSess of
Nothing -> st
Just (ScanSess c p d) ->
st & stScanSess .~ (Just $ ScanSess c (p+1) d)
getLatestPage :: St -> Int
getLatestPage st = case st^.stScanSess of
Nothing -> 0
Just (ScanSess _ p _ ) -> p
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