Does it make sense to have snip%'s copy method signal an error instead of returning a (useless) snip%? or maybe it could check and see if this is a subclass and signal an error in that case?
Robby On Tuesday, April 5, 2011, Matthias Felleisen <matth...@ccs.neu.edu> wrote: > > Please! > > On Apr 5, 2011, at 3:06 PM, Jay McCarthy wrote: > >> Should I update the docs to mention that as one that must be overridden? >> >> Jay >> >> 2011/4/5 Robby Findler <ro...@eecs.northwestern.edu>: >>> copy. >>> >>> Robby >>> >>> On Tue, Apr 5, 2011 at 1:34 PM, Jay McCarthy <jay.mccar...@gmail.com> wrote: >>>> I'm trying to create a useful snip that displays a different sub-snip >>>> every second. I think I've overridden every method required to get a >>>> "useful" snip, but nothing gets display in DrRacket and the functions >>>> aren't called ever. Are there other methods that need to be >>>> overridden? >>>> >>>> The code is below... >>>> >>>> Jay >>>> >>>> #lang racket/base >>>> (require (for-syntax racket/base) >>>> racket/class >>>> racket/function >>>> racket/runtime-path >>>> racket/snip) >>>> >>>> (define reactive-snip% >>>> (class* snip% () >>>> (init-field sub-snips) >>>> >>>> (printf "Snips: ~a\n" sub-snips) >>>> >>>> (define (the-snip) >>>> (list-ref sub-snips >>>> (modulo (current-seconds) (length sub-snips)))) >>>> >>>> (define-syntax-rule (delegate id) >>>> (define/override (id . a) >>>> (define some-snip (the-snip)) >>>> (printf "Delegating (~a ~a) to ~a\n" >>>> 'id a >>>> some-snip) >>>> (send/apply some-snip id a))) >>>> >>>> (delegate get-extent) >>>> (delegate draw) >>>> (delegate get-text) >>>> ; set-unmodified or modified >>>> >>>> (super-new))) >>>> >>>> (define-runtime-path img1 '(lib "PLT-206-larval.png" "icons")) >>>> (define-runtime-path img2 '(lib "PLT-206-mars.jpg" "icons")) >>>> >>>> (define sub-snips >>>> (map (curry make-object image-snip%) >>>> (list img1 img2))) >>>> >>>> (define x >>>> (make-object >>>> reactive-snip% >>>> sub-snips)) >>>> >>>> sub-snips >>>> >>>> x >>>> >>>> -- >>>> Jay McCarthy <j...@cs.byu.edu> >>>> Assistant Professor / Brigham Young University >>>> http://faculty.cs.byu.edu/~jay >>>> >>>> "The glory of God is Intelligence" - D&C 93 >>>> _________________________________________________ >>>> For list-related administrative tasks: >>>> http://lists.racket-lang.org/listinfo/users >>>> >>> >> >> >> >> -- >> Jay McCarthy <j...@cs.byu.edu> >> Assistant Professor / Brigham Young University >> http://faculty.cs.byu.edu/~jay >> >> "The glory of God is Intelligence" - D&C 93 >> >> _________________________________________________ >> For list-related administrative tasks: >> http://lists.racket-lang.org/listinfo/users > > _________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/users
