{-# OPTIONS -fglasgow-exts #-}
module ClientMessage where

import Data.Int
import Foreign
import Foreign.C.String
import Foreign.C.Types
import Graphics.X11.Xlib.Event
import Graphics.X11.Types
import Graphics.X11.Xlib.Types

#include <X11/X.h>
#include <X11/X.h>
#include <X11/Xlib.h>
#include <X11/Xatom.h>
#include <X11/Xutil.h>

type XClientMessageEvent = (Atom, ClientData)

data ClientData
    = ClientData8  [Int8]
    | ClientData16 [Int16]
    | ClientData32 [Int32]
      deriving Show

peekXButtonEvent :: Ptr XClientMessageEvent -> IO XClientMessageEvent
peekXButtonEvent p = do
	message_type    <- #{peek XClientMessageEvent,message_type} p
        format		<- #{peek XClientMessageEvent,format} p :: IO CInt
        let dataPtr     = #{ptr XClientMessageEvent,data.l} p :: Ptr ()
        data' <- case format of
                   8  -> peekArray 20 ((castPtr dataPtr) :: Ptr Int8)  >>= return . ClientData8
                   16 -> peekArray 10 ((castPtr dataPtr) :: Ptr Int16) >>= return . ClientData16
                   32 -> peekArray 5  ((castPtr dataPtr) :: Ptr Int32) >>= return . ClientData32
	return (message_type, data')

get_ClientMessageEvent :: XEventPtr -> IO XClientMessageEvent
get_ClientMessageEvent p = peekXButtonEvent (castPtr p)

foreign import ccall "XGetAtomName" c_xGetAtomName :: Ptr Display -> Atom -> IO CString


getAtomName :: Display -> Atom -> IO String
getAtomName (Display d) a = c_xGetAtomName d a >>= peekCString