{-# LANGUAGE ScopedTypeVariables, FlexibleInstances, MultiParamTypeClasses #-}
{-# OPTIONS_HADDOCK hide #-}
-- -*-haskell-*-
--  GIMP Toolkit (GTK) Pixbuf as Array
--
--  Author : Ciancia, Axel Simon
--
--  Created: 26 March 2002
--
--  Copyright (C) 2002-2005 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 : no (uses MTC, depends on internal GHC module)
--
-- 'PixbufData' exposes 'Pixbuf's as mutable array.
--

-- #hide
module Graphics.UI.Gtk.Gdk.PixbufData (
  PixbufData,
  mkPixbufData
  ) where

import System.Glib.FFI
import Graphics.UI.Gtk.Types
-- internal module of GHC
import Data.Array.Base ( MArray(..), newArray_, unsafeRead, unsafeWrite,
                         getBounds, getNumElements )

-- | An array that stored the raw pixel data of a 'Pixbuf'.
--
-- * See 'Graphics.UI.Gtk.Gdk.Pixbuf.pixbufGetPixels'.
--
data PixbufData i e = PixbufData !Pixbuf
                  {-# UNPACK #-} !(Ptr e)
                                 !(i,i)
                  {-# UNPACK #-} !Int

mkPixbufData :: Storable e => Pixbuf -> Ptr e -> Int -> PixbufData Int e
mkPixbufData :: forall e. Storable e => Pixbuf -> Ptr e -> Int -> PixbufData Int e
mkPixbufData Pixbuf
pb (Ptr e
ptr :: Ptr e) Int
size =
  Pixbuf -> Ptr e -> (Int, Int) -> Int -> PixbufData Int e
forall i e. Pixbuf -> Ptr e -> (i, i) -> Int -> PixbufData i e
PixbufData Pixbuf
pb Ptr e
ptr (Int
0, Int
count) Int
count
  where count :: Int
count = Int -> Int
forall a b. (Integral a, Num b) => a -> b
fromIntegral (Int
size Int -> Int -> Int
forall a. Integral a => a -> a -> a
`div` e -> Int
forall a. Storable a => a -> Int
sizeOf (e
forall a. HasCallStack => a
undefined :: e))

-- | 'PixbufData' is a mutable array.
instance Storable e => MArray PixbufData e IO where
  newArray :: forall i. Ix i => (i, i) -> e -> IO (PixbufData i e)
newArray (i
l,i
u) e
e = [Char] -> IO (PixbufData i e)
forall a. HasCallStack => [Char] -> a
error [Char]
"Gtk.Gdk.Pixbuf.newArray: not implemented"
  newArray_ :: forall i. Ix i => (i, i) -> IO (PixbufData i e)
newArray_ (i
l,i
u)  = [Char] -> IO (PixbufData i e)
forall a. HasCallStack => [Char] -> a
error [Char]
"Gtk.Gdk.Pixbuf.newArray_: not implemented"
  {-# INLINE unsafeRead #-}
  unsafeRead :: forall i. Ix i => PixbufData i e -> Int -> IO e
unsafeRead (PixbufData (Pixbuf ForeignPtr Pixbuf
pb) Ptr e
pixPtr (i, i)
_ Int
_) Int
idx = do
      e
e <- Ptr e -> Int -> IO e
forall a. Storable a => Ptr a -> Int -> IO a
peekElemOff Ptr e
pixPtr Int
idx
      ForeignPtr Pixbuf -> IO ()
forall a. ForeignPtr a -> IO ()
touchForeignPtr ForeignPtr Pixbuf
pb
      e -> IO e
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return e
e
  {-# INLINE unsafeWrite #-}
  unsafeWrite :: forall i. Ix i => PixbufData i e -> Int -> e -> IO ()
unsafeWrite (PixbufData (Pixbuf ForeignPtr Pixbuf
pb) Ptr e
pixPtr (i, i)
_ Int
_) Int
idx e
elem = do
      Ptr e -> Int -> e -> IO ()
forall a. Storable a => Ptr a -> Int -> a -> IO ()
pokeElemOff Ptr e
pixPtr Int
idx e
elem
      ForeignPtr Pixbuf -> IO ()
forall a. ForeignPtr a -> IO ()
touchForeignPtr ForeignPtr Pixbuf
pb
  {-# INLINE getBounds #-}
  getBounds :: forall i. Ix i => PixbufData i e -> IO (i, i)
getBounds (PixbufData Pixbuf
_ Ptr e
_ (i, i)
bd Int
_) = (i, i) -> IO (i, i)
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return (i, i)
bd
  {-# INLINE getNumElements #-}
  getNumElements :: forall i. Ix i => PixbufData i e -> IO Int
getNumElements (PixbufData Pixbuf
_ Ptr e
_ (i, i)
_ Int
count) = Int -> IO Int
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return Int
count