Bart,
I have been meaning to contribute this to Helmut's page, but never got 
around
to it. I will do so shortly now. Anyway, I have always wanted a 
graphics editor
with BlackBox and never had the time to work on one. I developed a 
module
named ShapesDraw, however, that could serve to render primitive shapes 
for
the editor. It exports the following procedures:

Arc, a 90 degree arc
RoundedRect, a rectangle with rounded corners
Arrow, an arrow with a solid shaft
PathArrow, an arrow with a hollow interior
Pie, a segment of a pie chart
Sin, an efficient computation of sine
Cos, an efficient computation of cosine

I think the arrow routines are particularly nice, as you can specify 
the exact shape
of the arrowheads. You can even put them on either or both ends of a 
Bezier curve.
Integer arithmetic is used for efficiency, and angles are specified to 
a precision
of 1/64 of one degree. The module is well-documented. It has a suite of 
test programs
including some with animation. The BlackBox system is particularly 
nice, as you
get resolution-independent rendering for hardcopy output. Anyone is 
welcome to
use the module as one of the building blocks of a BlackBox editor.

Best regards,
Stan

On Jun 3, 2004, at 7:12 AM, Wijck, Bart van wrote:

> All,
>
> I'd like to be able to use a Visio style editor view. The user would 
> be able
> to draw a graph using visual components from a palet (e.g. activity and
> product icons), or from a menu and draw arrows between them. It would 
> be
> nice if they snapped onto the icon (anchor points) and the arrows move 
> if
> the icons are dragged elsewhere. Icons (and attached lines) should be 
> able
> to be deleted.
>
> Clicking on for icons should provide forms for details (name etc).
>
> Possibly clicking with the right mouse button (or some other method) 
> on the
> activity icon should open a second editor view to create a diagram of
> activities and products at a lower level (decomposition).
>
> Is there a subsystem which comes somewhere close to the above? It 
> sounds
> rather specific but could be quite generically useful.
>
> Regards, Bart

odin