[plt-scheme] a snip copy/paste puzzle
Do you get a stacktrace with the error message?
Robby
On Sat, Aug 8, 2009 at 1:57 AM, Jordan Johnson<jmj at fellowhuman.com> wrote:
> Hi all,
>
> I've been working on a snip implementation (representing an annotated
> expression) and am getting a mysterious error. I'd be grateful for any help
> the community can offer in solving the problem.
>
> The error: Currently when I attempt to copy and paste my snip, I get the
> error
>
> set-editor method of editor-snip%: expects argument of type
> <interface:editor% instance>; given #f
>
> ...and the editor-snip% in question is apparently not any of the snips I've
> defined, which I've verified by overriding their set-editor method. This
> error is coming from somewhere deep in MrEd, and (after embarrassingly many
> hours of reading internal code and probing/rewriting) I don't see the cause.
>
> Below is a version I've pared down to just what's necessary to see the
> structure and exercise the bug. To reproduce the error: run it, evaluate
> (test-w/text%), and attempt to copy and paste the editor-snip% you see in
> the frame it created.
>
> Any observations?
>
> Thanks,
> jmj
>
> ;;;;;;; code-desc-simplified.ss
>
> #lang scheme/gui
>
> (require framework embedded-gui)
> (provide anno-snip%)
>
> ;;;;;;;;;; Snipclassery (for cut/paste) ;;;;;;;;;;;
> ;; Design follows framework/private/comment-box.ss lines 23-31
> (define anno-snipclass%
> (class decorated-editor-snipclass%
> (define/override (make-snip stream-in) (new anno-snip%))
> (define/override (read in)
> (let ([pb (new anno-pb%)])
> (let ([code-ed (send pb get-code-editor)]
> [anno-ed (send pb get-anno-editor)])
> (send code-ed read-from-file in 'start)
> (send anno-ed read-from-file in 'start))))
>
> (super-new)))
>
> (define snipclass (make-object anno-snipclass%))
> (send snipclass set-version 1)
> (send snipclass set-classname "code-desc-snip.ss")
> (send (get-the-snip-class-list) add snipclass)
>
>
> ;;;; Snip representing an annotated chunk of code.
> (define anno-snip%
> (class decorated-editor-snip%
>
> (define/override (make-editor) (new anno-pb%))
> (define/override (make-snip) (new anno-snip%))
>
> ;; copy/paste:
> (inherit get-editor)
> (define/override (write stream-out)
> (let ([pb (get-editor)])
> (let ([code (send pb get-code-editor)]
> [anno (send pb get-anno-editor)])
> (send code write-to-file stream-out)
> (send anno write-to-file stream-out))))
>
> (define/override (copy) ;; -> anno-snip%
> ;; return a copy of this snip
> (let ([s (new anno-snip%)])
> (send s set-editor (send (get-editor) copy-self))
> s))
>
> (super-new)
> ))
>
> (define anno-pb%
> (let ()
> (define (find-owner-snip ed) ;; editor<%> -> (union #f editor-snip%)
> (let ([admin (send ed get-admin)])
> (and admin
> (admin . is-a? . editor-snip-editor-admin<%>)
> (send admin get-snip))))
> (define scheme+copy-self% ;; class for the code editor
> (class scheme:text% ;; (from framework/private/comment-box.ss)
> (inherit copy-self-to)
> (init-field [kind 'default])
> (define/override (copy-self)
> (let ([ed (new scheme+copy-self%)])
> (copy-self-to ed)
> ed))
> (super-new)
> (inherit set-max-undo-history)
> (set-max-undo-history 'forever)))
> (class aligned-pasteboard%
> (super-new)
>
> ;;;;;;; Component editors:
> ;; code-editor and anno-editor are the two text%s that contain the
> ;; code and annotation, respectively.
> ;; -> (union #f text%)
> (define/public (get-code-editor) code-editor)
> (define/public (make-code-editor) (new scheme+copy-self%
> [kind 'code]))
> ;; -> (union #f text%)
> (define/public (get-anno-editor) anno-editor)
> (define/public (make-anno-editor) (new text%))
>
> (define code-editor (make-code-editor)) ;; code box's editor
> (define anno-editor (make-anno-editor)) ;; annotation box's
>
> ;;;;;;; Container snips for the text editors:
>
> (define val (new vertical-alignment% [parent this]))
> ;; Container for the code box. I'm using this for the ability to
> ;; show/hide the box:
> (define code-view (new vertical-alignment%
> [parent val]
> [show? #t]))
>
> ;; Installs stretchable editor snips, if none are already installed,
> ;; to contain the code and anno editors.
> ;; (Does nothing if they already are installed, and returns #f.)
> ;; Returns #t if successful.
> (define (init-snips)
> (and (not (or (find-owner-snip code-editor)
> (find-owner-snip anno-editor)))
> (let ([code-snip (new stretchable-editor-snip%
> [editor code-editor]
> [with-border? #t]
> [min-width 50])]
> [anno-snip (new stretchable-editor-snip%
> [editor anno-editor]
> [with-border? #f]
> [min-width 50])])
> (make-object snip-wrapper% code-view code-snip)
> (make-object hline% code-view)
> (make-object snip-wrapper% val anno-snip)
> #t)))
>
> (init-snips)
>
> ;;;;;;;;; copy+paste ;;;;;;;;;
>
> (define/override (copy-self)
> (let ([ed (new anno-pb%)])
> (let ([ed-code (send ed get-code-editor)]
> [ed-anno (send ed get-anno-editor)])
> (send (get-code-editor) copy-self-to ed-code)
> (send (get-anno-editor) copy-self-to ed-anno)
> ed)))
> )))
>
> ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
> (define (test-w/text%)
> (define test-snip (new anno-snip%))
> (define test-pb (send test-snip get-editor))
> (define txt (new scheme:text%))
> (define f (mk-test-frame))
> (define c (new editor-canvas% [parent f][editor txt]))
> (send txt insert "\n(* x 3)\n4))" 0)
> (send txt insert test-snip 0)
> (send txt insert "(define (f x)\n(+ " 0)
> (send txt tabify-all)
> (send f show #t)
> )
> (define (mk-test-frame)
> (new frame% [label "ah"] [width 500] [height 300]
> [alignment '(center center)]))
>
>
>
>
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