{-# LANGUAGE FlexibleContexts, FlexibleInstances
  , MultiParamTypeClasses, TemplateHaskell, UndecidableInstances #-}


{- Who made what?

Shelarcy made the AFDirectoryPath extension.

The rest is made by Mads Lindstrøm.

-}

-- |Contain types which implementations of the 'AutoForm' class should handle specially.
module Graphics.UI.AF.General.CustomTypes
    ( AFFilePath(..)
    , AFDirectoryPath(..)
    , afOpenFile
    )
where


import Graphics.UI.AF.General.MySYB

import IO
import Graphics.UI.AF.General.AutoForm

-- |Contains a file system pointer in form of a text string, just like FilePath.
-- A new type were needed as FilePath is just a type synonym (for string). Otherwise,
-- It would be impossible to behave in one way for strings and another for file paths.
newtype AFFilePath = AFFilePath { filePath :: String } deriving (Show, Read, Eq)

-- |afOpenFil is the counterpart of IO.openFile, just using AFFilePath
-- instead.
afOpenFile :: AFFilePath -> IOMode -> IO Handle
afOpenFile (AFFilePath path) mode = openFile path mode

-- Note that, a list of AFFilePath should probably also behave
-- specially, like being able to select multiple files in a file
-- requester dialog. But this is not implemented yet.

$(derive [''AFFilePath])

instance (AutoForm action comH builder satCxt com) => TypePresentation AFFilePath action comH builder satCxt com

-- |AutoForms directory path -type. A new type is needed for the same
--  reason it was needed for 'AFFilePath'.
newtype AFDirectoryPath = AFDirectoryPath { directoryPath :: String } deriving (Show, Read, Eq)

instance (AutoForm action comH builder satCxt com) => TypePresentation AFDirectoryPath action comH builder satCxt com
$(derive [''AFDirectoryPath])