Stklos question

From: Jen Mankoff <jmankoff_at_cs.oberlin.edu>
Date: Fri, 27 Jan 1995 23:32:20 -0500

I'm having trouble with composite-classes in STklos. Below is a
session in STk and the code that's giving me trouble. I've simplified
the code down to the basic stuff that seems to cause the error: in the
full application, there is a need for the hierarchy I've chosen. If
anyone can help me fix this problem, I'd greatly appreciate the help.

Thanks alot

        -jen mankoff
        -jmankoff_at_cs.oberlin.edu

***************************** STk session ***********************
STk> (begin (require "Canvas") (define c (make <Canvas>)) (pack c))
<... munch ...>
STk> (define b (make <barplot> :parent c :coords '(1 2 3 4) :data '(foo) :numbars 3))

*** Error:
    initialize-item: no method for #[<barplot> 100c2c34] subclass
Current eval stack:
__________________
  0 (error "initialize-item: no method for ~S subclass" self)
  1 (initialize-item self parent-id coords initargs)
  2 (let ((cid (initialize-item self parent-id coords initargs))) (slot-set! self (quote cid) cid))
  3 (initialize instance (append other-args (list :tk-options tk-options)))
  4 (letrec ((instance (allocate-instance class initargs)) (valids (slot-ref class (quote tk-valid-options))) (tk-options ()) (other-args ())) (letrec ((|G2| (lambda (args) (if (null? args) (begin #[undefined]) (begin (let ((opt (tk::find-option (car args) valids))) (if opt (set! tk-options (list* (vector-ref opt 1) (cadr args) tk-options)) (set! other-args (list* (car args) (cadr args) other-args)))) (|G2| (cddr args))))))) (|G2| initargs)))
...
STk>

**************************** my code ****************************

;; data-store keeps data and other information
;; which can be be represented, among other ways,
;; as a barplot (see below)

(define-class <data-store> ()
  ((data ;; passed in
    :init-keyword :data
    :accessor data)))

(define-method initialize-item
  ((self <data-store>) args)
  (slot-set! 'data (get-keyword :data args)))

;; barplot inherits from Tk (so it can draw in a canvas)
;; and from data-store (it's source of data & info about the data)
(define-class <barplot> (<Tk-composite-item> <data-store>)
  ((numbars
    :accessor barspace)))

(define-method initialize-item
  ((self <barplot>) parent coords data args)
  (let* ((parent (slot-ref self 'parent))
         (numbars (get-keyword :numbars initargs 3))
         (data (get-keyword :data initargs))
         )
    (slot-set! self 'numbars numbars)))
Received on Sat Jan 28 1995 - 05:33:37 CET