-- A little demo program that was proposed on gui@haskell.org to compare
-- toolkit APIs.  This is a version for the iHaskell API.
--
-- There is a single button, which, when clicked once, changes the display
-- and, when clicked a second time, terminates the application.
--

import Monad

import Gtk       (binGetChild)
import IH hiding (init, main)
import qualified
       IH        (init, main)

main :: IO ()
main = 
  do
    IH.init Nothing

    -- create a counter for clicks
    --
    clicksPort <- newPort 0

    -- create the label and button, where the button increments the click count
    --
    label  <- newLabel " Hello World "
    button <- newButtonWithLabel " Bye " (clicksPort <-$ (+1))
    butlbl <- liftM fromWidget $ binGetChild button :: IO Label

    -- pack the label and button vertically and embed them into a window
    --
    contents <- newBox Vertical True 10 [widget label, widget button]
    newWindow " Bye Demo " contents mainQuit False

    -- clicks are handled by `handleClick' depending on the number of clicks
    --
    let
      handleClick 2 = mainQuit
      handleClick 1 = do
		        setLabelText label  " Goodbye "
			setLabelText butlbl " Exit "
    clicks <- listenToPort clicksPort
    forkIO $ mapM_ handleClick clicks

    -- enter the event loop
    --
    IH.main