implementation module Gtk.Signal

import StdEnv

import Control.Monad
import Control.Monad.Identity
import Control.Monad.State
import qualified Data.Map

import Gtk.Internal
import Gtk.State
import Gtk.Widgets

installSignalHandler :: !GSignalHandler !w -> State GtkState w | gtkWidget w
installSignalHandler handler widget =
	modify (\st ->
		{ st
		& signal_handlers = 'Data.Map'.put (st.signal_counter+1) handler_internal st.signal_handlers
		, signal_counter  = st.signal_counter+1
		}) >>|
	gets (\st -> st.signal_counter) >>= \id ->
	(toState case handler_internal of
		GSHI_Void _ -> g_signal_connect_void (toPtr (gtkWidget widget)) signal_name id) >>|
	pure widget
where
	(signal_name,handler_internal) = case handler of
		DestroyHandler f  -> ("destroy", GSHI_Void f)
		ActivateHandler f -> ("activate",GSHI_Void f)