[plt-scheme] drawing in MrEd's pasteboards

From: nik gaffney (nik at fo.am)
Date: Fri Sep 8 11:20:24 EDT 2006

>> from the description of a pasteboard% it looks like it should be possible
>> to do similar path based drawing in a within an editor-canvas% as in a 
>> canvas% draw context. however, i cant seem to find an obvious way to get
>> this working with out resorting to creating bitmaps, then using
>> image-clip%, is there a more straightforward method of drawing into a
>> pasteboard ?+
> You should be able to do the same things in a canvas% and in an
> editor-canvas% (the second has more going on, so you may need to be a
> little more careful about ordering of drawing, tho). In particular, they
> both draw into a canvas-dc, so you should be able to use all the same
> path stuff in both places.
> What's going wrong?

to perhaps clarify, i would like to be able to draw a path based object into an
editor-canvas, and be able to move or resize it.

so, from what i understand of how the editor canvas works, id like to know an
idiomatic way to get a function such as the following to draw into an
image-snip%  ->

(a-drawing-function (send an-editor-canvas get-dc))

what im currently doing is something like ->

(define offscreen (make-object bitmap% 16 100 100))
(define bdc (make-object bitmap-dc% offscreen))

(a-drawing-function bdc)
(send bdc set-bitmap #f)

(define img (make-object image-snip% offscreen #f))
(send p insert img)

which looks rather awkward, especially for redrawing and scaling. so im just
wondering if im going about this in the wrong way?


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