-- GENERATED by C->Haskell Compiler, version 0.13.13 (gtk2hs branch) "Bin IO", 27 May 2012 (Haskell)
-- Edit the ORIGINAL .chs file instead!


{-# LINE 1 "./System/Glib/GString.chs" #-}
-- -*-haskell-*-
--  GIMP Toolkit (GTK)
--
--  Author : Andreas Baldeau
--
--  Created: 14 November 2010
--
--  Copyright (C) 2010 Andreas Baldeau
--
--  This library is free software; you can redistribute it and/or
--  modify it under the terms of the GNU Lesser General Public
--  License as published by the Free Software Foundation; either
--  version 2.1 of the License, or (at your option) any later version.
--
--  This library 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
--  Lesser General Public License for more details.
--
-- |
-- Maintainer  : gtk2hs-users@lists.sourceforge.net
-- Stability   : provisional
-- Portability : portable (depends on GHC)
--
-- Defines functions to extract data from a GString.
--
module System.Glib.GString (
  GString,
  readGString,
  readGStringByteString,
  fromGString,
  ) where

import Foreign
import Control.Exception        (bracket)
import Control.Monad            (foldM)
import Data.ByteString          (ByteString, packCStringLen)

import System.Glib.FFI


{-# LINE 41 "./System/Glib/GString.chs" #-}

type GString = Ptr (())
{-# LINE 43 "./System/Glib/GString.chs" #-}

-- methods

-- Turn a GString into a String but don't destroy it.
--
readGString :: GString -> IO (Maybe String)
readGString :: GString -> IO (Maybe String)
readGString GString
gstring
  | GString
gstring GString -> GString -> Bool
forall a. Eq a => a -> a -> Bool
== GString
forall a. Ptr a
nullPtr = Maybe String -> IO (Maybe String)
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return Maybe String
forall a. Maybe a
Nothing
  | Bool
otherwise          = do
    Ptr CChar
gstr <- (\GString
ptr -> do {GString -> Int -> IO (Ptr CChar)
forall b. Ptr b -> Int -> IO (Ptr CChar)
forall a b. Storable a => Ptr b -> Int -> IO a
peekByteOff GString
ptr Int
0 ::IO (Ptr CChar)}) GString
gstring
    CULong
len <- (\GString
ptr -> do {GString -> Int -> IO CULong
forall b. Ptr b -> Int -> IO CULong
forall a b. Storable a => Ptr b -> Int -> IO a
peekByteOff GString
ptr Int
8 ::IO CULong}) GString
gstring
    (String -> Maybe String) -> IO String -> IO (Maybe String)
forall a b. (a -> b) -> IO a -> IO b
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap String -> Maybe String
forall a. a -> Maybe a
Just (IO String -> IO (Maybe String)) -> IO String -> IO (Maybe String)
forall a b. (a -> b) -> a -> b
$ CStringLen -> IO String
peekCStringLen (Ptr CChar
gstr, CULong -> Int
forall a b. (Integral a, Num b) => a -> b
fromIntegral CULong
len)

-- Turn a GString into a ByteString but don't destroy it.
--
readGStringByteString :: GString -> IO (Maybe ByteString)
readGStringByteString :: GString -> IO (Maybe ByteString)
readGStringByteString GString
gstring
  | GString
gstring GString -> GString -> Bool
forall a. Eq a => a -> a -> Bool
== GString
forall a. Ptr a
nullPtr = Maybe ByteString -> IO (Maybe ByteString)
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return Maybe ByteString
forall a. Maybe a
Nothing
  | Bool
otherwise          = do
    Ptr CChar
gstr <- (\GString
ptr -> do {GString -> Int -> IO (Ptr CChar)
forall b. Ptr b -> Int -> IO (Ptr CChar)
forall a b. Storable a => Ptr b -> Int -> IO a
peekByteOff GString
ptr Int
0 ::IO (Ptr CChar)}) GString
gstring
    CULong
len <- (\GString
ptr -> do {GString -> Int -> IO CULong
forall b. Ptr b -> Int -> IO CULong
forall a b. Storable a => Ptr b -> Int -> IO a
peekByteOff GString
ptr Int
8 ::IO CULong}) GString
gstring
    (ByteString -> Maybe ByteString)
-> IO ByteString -> IO (Maybe ByteString)
forall a b. (a -> b) -> IO a -> IO b
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap ByteString -> Maybe ByteString
forall a. a -> Maybe a
Just (IO ByteString -> IO (Maybe ByteString))
-> IO ByteString -> IO (Maybe ByteString)
forall a b. (a -> b) -> a -> b
$ CStringLen -> IO ByteString
packCStringLen (Ptr CChar
gstr, CULong -> Int
forall a b. (Integral a, Num b) => a -> b
fromIntegral CULong
len)

-- Turn a GList into a list of pointers (freeing the GList in the process).
--
fromGString :: GString -> IO (Maybe String)
fromGString :: GString -> IO (Maybe String)
fromGString GString
gstring
  | GString
gstring GString -> GString -> Bool
forall a. Eq a => a -> a -> Bool
== GString
forall a. Ptr a
nullPtr = Maybe String -> IO (Maybe String)
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return Maybe String
forall a. Maybe a
Nothing
  | Bool
otherwise          = do
    Ptr CChar
gstr <- (\GString
ptr -> do {GString -> Int -> IO (Ptr CChar)
forall b. Ptr b -> Int -> IO (Ptr CChar)
forall a b. Storable a => Ptr b -> Int -> IO a
peekByteOff GString
ptr Int
0 ::IO (Ptr CChar)}) GString
gstring
    CULong
len <- (\GString
ptr -> do {GString -> Int -> IO CULong
forall b. Ptr b -> Int -> IO CULong
forall a b. Storable a => Ptr b -> Int -> IO a
peekByteOff GString
ptr Int
8 ::IO CULong}) GString
gstring
    Maybe String
str <- (String -> Maybe String) -> IO String -> IO (Maybe String)
forall a b. (a -> b) -> IO a -> IO b
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap String -> Maybe String
forall a. a -> Maybe a
Just (IO String -> IO (Maybe String)) -> IO String -> IO (Maybe String)
forall a b. (a -> b) -> a -> b
$ CStringLen -> IO String
peekCStringLen (Ptr CChar
gstr, CULong -> Int
forall a b. (Integral a, Num b) => a -> b
fromIntegral CULong
len)
    Ptr CChar
_ <- GString -> CInt -> IO (Ptr CChar)
g_string_free GString
gstring (CInt -> IO (Ptr CChar)) -> CInt -> IO (Ptr CChar)
forall a b. (a -> b) -> a -> b
$ Bool -> CInt
forall a. Num a => Bool -> a
fromBool Bool
True
    Maybe String -> IO (Maybe String)
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return Maybe String
str


foreign import ccall unsafe "g_string_free"
  g_string_free :: ((Ptr ()) -> (CInt -> (IO (Ptr CChar))))