(***********************************************************************)
(*                                                                     *)
(*                           Objective Caml                            *)
(*                                                                     *)
(*               Pierre Weis, projet Cristal, INRIA Rocquencourt       *)
(*                                                                     *)
(*  Copyright 2001 Institut National de Recherche en Informatique et   *)
(*  en Automatique.  All rights reserved.  This file is distributed    *)
(*  under the terms of the Q Public License version 1.0.               *)
(*                                                                     *)
(***********************************************************************)

(* The toggling buttons hello world program: creates two buttons, one
simple button to quit the program, and another one with two mutually
recursive callbacks functions. Those callback functions configure the
button with a new text and simultaneously change the current call back
function of the button to reinstall the other callback.
   
Compile using:
 ocamlc -I +labltk -c hello_quit.ml
Link using:
 ocamlc -I +labltk -custom labltk.cma  hello_quit.cmo -o hello_quit

Try with ./hello_quit

*)

open Camltk;;

let hello_quit () =
  let main_window = openTk () in
  let bouton_quit =
    Button.create main_window
      [Text "Quit"; Command closeTk] in
  let bouton_press = Button.create main_window [] in
  let rec action_press () =
    Button.configure bouton_press
      [Text "Hello!"; Command press_init]
  and press_init () =
    Button.configure bouton_press
      [Text "Press"; Command action_press] in
  press_init ();
  pack [bouton_press; bouton_quit] [Side Side_Left];
  mainLoop ();;

if !Sys.interactive then () else begin hello_quit(); exit 0 end;;