[plt-scheme] text% : snips, styles and delta-styles

Hi folks

Inside a text% editor, I trying to change the delta-style from some snips.
However, when I change the delta-style for a style for the first snip,
all the text in the editor get the same style, even if I change the
delta style for others snip further.

Maybe I missed something about styles and delta-styles...

Here is my code for changing the styles :
  (define colorize
    (lambda (a-text)
      (let* ((input (open-input-string (send a-text get-text)))
             (lex (makeLexer input))
             (lexed (analyse-all lex))) ; lexed is a list of (id text position)
        (let ((oldIndex 0) ; It is unused right now
              (color-snip
               (lambda (l)
                 (let ((type (car l)) (pos (caddr l)))
                   (send a-text split-snip pos) ;  for splitting snips
                   (let ((snip (send a-text find-snip pos 'before))) ;
and get the one before
                     (printf "~a: ~a~n" type (send snip get-text 0
(send snip get-count)))
                     (let ((snip-style (send snip get-style))
(new-snip-delta (assv type get-delta)))
                       (when new-snip-delta
                         (let ((snip-delta (cadr new-snip-delta)))
                           (send snip-style get-delta snip-delta)
                           (send snip-style set-delta (send snip-delta
set-delta-foreground (cadr (assv type types-style))))))
                       ))))))
          (for-each color-snip lexed)))
      ))

get-delta is a a-list with delta styles :
  (define get-delta
    `(; Syntax: (identifier a-style-delta)
      (keyword ,(let ((new-delta (make-object style-delta%
'change-normal-color)))
                  (send new-delta set-delta-foreground "blue")))
      (empty ,(let ((new-delta (make-object style-delta% 'change-normal-color)))
               (send new-delta set-delta-foreground "orange")))
      (string ,(let ((new-delta (make-object style-delta%
'change-normal-color)))
                  (send new-delta set-delta-foreground "green")))
      (int ,(let ((new-delta (make-object style-delta% 'change-normal-color)))
                  (send new-delta set-delta-foreground "red"))))
    )

and types-style is another a-list with (keyword "color") elements.


For my example, all the editor is orange colored, because the first
snip style is linked with empty, for other snip, with get-style,
get-delta and get-delta-foreground, I'm able to see that the colors in
the delta are differents, but these differences are not visible.


Does anyone has an example with style-list, snip and colors for a text% object ?


Thanks,
-- 
Cyprien Nicolas