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|
-- -*-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
{# context lib="glib" prefix="g" #}
{#pointer * GString#}
-- methods
-- Turn a GString into a String but don't destroy it.
--
readGString :: GString -> IO (Maybe String)
readGString gstring
| gstring == nullPtr = return Nothing
| otherwise = do
gstr <- {#get GString->str#} gstring
len <- {#get GString->len#} gstring
fmap Just $ peekCStringLen (gstr, fromIntegral len)
-- Turn a GString into a ByteString but don't destroy it.
--
readGStringByteString :: GString -> IO (Maybe ByteString)
readGStringByteString gstring
| gstring == nullPtr = return Nothing
| otherwise = do
gstr <- {#get GString->str#} gstring
len <- {#get GString->len#} gstring
fmap Just $ packCStringLen (gstr, fromIntegral len)
-- Turn a GList into a list of pointers (freeing the GList in the process).
--
fromGString :: GString -> IO (Maybe String)
fromGString gstring
| gstring == nullPtr = return Nothing
| otherwise = do
gstr <- {#get GString->str#} gstring
len <- {#get GString->len#} gstring
str <- fmap Just $ peekCStringLen (gstr, fromIntegral len)
_ <- {#call unsafe string_free#} gstring $ fromBool True
return str
|
