;; b = button, i = state, l = texts, f = recv, w = width, h = height

(define-struct clkr* 
  (field b i l f)
  #:mutable)

(define (make-clkr p w h l f)
  (let* ((b (make-button p w h (car l) #f))
	 (c (make-clkr* b 0 l f))
	 (n (length l)))
    (edit-button-recv
     b (lambda ()
	 (let* ((l (clkr*-l c))
		(n (length l))
		(f (clkr*-f c))
		(i (clkr*-i c)))
	   (set! i (modulo (+ i 1) n))
	   (edit-button-text b (list-ref l i))
	   (f i)
	   (set-clkr*-i! c i))))
    c))

(define (edit-clkr-texts c l)
  (set-clkr*-l! c l)
  (set-clkr*-i! c 0)
  (edit-button-text (clkr*-b c) (car l)))

(define (edit-clkr-recv c f)
  (set-clkr*-f! c f))

(define (edit-clkr-font c v)
  (edit-button-font (clkr*-b c) v))