use std::stream::const
use std::stream::head
use gui::widget::*
use gui::color::*
use gui::shape::*

let ui = gui::frame (100,50)

let (btn_id, btn_stream) = button ui (100, 50) (const "Click me!")

let counter = {
  let aux = fn n -> {
    let delta = if head btn_stream then 1 else 0;
    (n + delta) << @(aux (n + delta))
  };
  aux 0
}
let counter_string = std::int_to_string (head counter) << @counter_string

let (lab_id, lab_stream) = label ui (100, 50) counter_string 

let (grp_id, grp_stream) = hgroup 
  ui 
  (250,100) 
  (const [btn_id, lab_id]) 
  (Alignment::Top)

let _ = gui::attach_root (ui, grp_id)

let circle_color = 
  (if head counter % 3 == 0 then 
    red
  else if head counter %3 == 1 then
    green
  else 
    blue) << @circle_color

let circle = (draw_shape (Shape::Circle((200,200), 30, head circle_color))) << @circle

let print_on_btn = (if head btn_stream then (print_message "Button Clicked!") else ()) << @print_on_btn

let mouse_circle = (draw_shape (
  Shape::Circle(
    head (gui::input::mouse_pos_str ()),
    10,
    red
  ))) << @mouse_circle