1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
|
-- -*-haskell-*-
-- GIMP Toolkit (GTK) GValue
--
-- Author : Axel Simon
--
-- Created: 1 June 2001
--
-- Copyright (c) 1999..2002 Axel Simon
--
-- 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)
--
-- This module implements only the necessities for the GTK binding.
--
-- * Everything here is only used by "Graphics.UI.Gtk.TreeList.TreeModel" and
-- friends.
--
module System.Glib.GValue (
GValue(GValue),
valueInit,
valueGetType,
allocaGValue
) where
import System.Glib.FFI
import System.Glib.GType (GType)
{# context lib="glib" prefix="g" #}
{# pointer *GValue newtype #}
-- | Clear a GValue.
--
valueInit :: GValue -> GType -> IO ()
valueInit gv gt = do
-- The g_type field of the value must be zero or g_value_init will fail.
{# call unsafe value_init #} gv gt
return ()
-- | Get the type of the value stored in the GValue
--
valueGetType :: GValue -> IO GType
valueGetType (GValue gvPtr) = {# get GValue->g_type #} gvPtr
-- | Temporarily allocate a GValue.
--
allocaGValue :: (GValue -> IO b) -> IO b
allocaGValue body =
-- c2hs is broken in that it can't handle arrays of compound arrays in the
-- sizeof hook
allocaBytes ({# sizeof GType #}+ 2* {# sizeof guint64 #}) $ \gvPtr -> do
-- The g_type field of the value must be zero or g_value_init will fail.
{# set GValue->g_type #} gvPtr (0 :: GType)
result <- body (GValue gvPtr)
{#call unsafe value_unset#} (GValue gvPtr)
return result
|
