Re: [Chicken-users] iup cells draw callback

[Martin DeMello]

This is the code from which the error message was thrown:

(define-values (callback-set! callback)

  (letrec ([signature/raw

            (foreign-lambda* c-string ([nonnull-ihandle handle] [iname/upcase name])

              "C_return(iupClassCallbackGetFormat(handle->iclass, name));")]

           [set/pointer!

            (foreign-lambda c-pointer "IupSetCallback" nonnull-ihandle iname/upcase c-pointer)]

           [get/pointer

            (foreign-lambda c-pointer "IupGetCallback" nonnull-ihandle iname/upcase)]

           [sigils

            (irregex "([bifdsvh]*)(?:=([bifdvh]))?")]

           [callback-set!

            (lambda (handle name proc)

              (let* ([sig

                      (cond

                        [(irregex-match sigils (or (signature/raw handle name) ""))

                         => (lambda (groups)

                              (string-append

                                (or (irregex-match-substring groups 2) "i")

                                (irregex-match-substring groups 1)))]

                        [else

                         (error 'callback-set! "callback has bad signature" handle name)])]

Looking up iupClassCallbackGetFormat here:

http://webserver2.tecgraf.puc-rio.br/iup/doxygen/group__iclass.html#ga5733bfa0e0889ec4e4293c2a57205650

it looks like the cb-draw callback has format "iiiiiiC", which doesn't match the sigil regex. I take it that means callbacks with a Canvas* argument are unsupported in chicken-iup?

martin

On Wed, Oct 14, 2015 at 12:51 AM, Martin DeMello <address@hidden> wrote:

Hi,

I'm trying to port the chessboard example from IUP to chicken. The C code is here:

http://webserver2.tecgraf.puc-rio.br/iup/examples/C/cells_checkboard.c

I'm stuck when trying to add a draw callback - it crashes with 

Error: (callback-set!) callback has bad signature

The code is here: https://gist.github.com/martindemello/2f8ba4ccfebed3bd4650 or below:

(use iup)

(define (nlines self) 8)

(define (ncols self) 8)

(define (height self line) 50)

(define (width self col) 50)

(define (draw self i j xmin xmax ymin ymax canvas) 'default)

(define dlg

  (dialog

    (vbox

      (cells name: "Chessboard"

             height-cb: height

             width-cb: width

             nlines-cb: nlines

             ncols-cb: ncols

             draw-cb: draw)

      (button title: 'E&xit

              expand: 'Yes

              tip: "Close button"

              action: (lambda (self) 'close)))

    title: 'IUP))

(show dlg)

(main-loop)

(destroy! dlg)

(exit 0)

martin