Re: Rounded Polyline, and other questions?

[anthonym overture com]

On Tue, Apr 27, 2004 at 07:58:54AM +0200, Lars Clausen wrote:
> >   I believe the best approach to accomplishing what I want to do would
> > be to migrate the rounded arrow code from the SADT object into the
> > diarenderer.  I'ved create a couple of functions called 'draw_rounded_polyline'
> > and 'draw_rounded_polyline_with_arrows', and copied the code from the
> > SADT arrow into the first.  I'll then probably move the arrow and point
> > adjusting code from the draw_polyline_with_arrows into a common function
> > so it can be shared.  I can then call the rounded version of
> > draw_polyline_with_arrows in my object.
> 
> And you're making a default implementation of draw_rounded_polyline* in
> DiaRenderer, yes?

Yeah, that's where I put it.  Right now its copied fairly verbatim from
the SADT arrow class, which uses draw_line and draw_arc so should be
applicable to subclasses of the Renderer which support those functions.

> >   With the above approach my programmed objects essentially become a
> > constrained version of the zigzagline, which seems like a much cleaner
> > approach than some of the other arrow type programmed objects I've
> > looked at.  I don't know if it is actually possible to extend zigzagline
> > or whether I need to essentially copy it and add in the constraints?
> 
> It ought to be possible to extend the zigzagline, but methinks the
> properties and object menus will get in the way -- notice how they're
> defined with macros for polyline.  If you can think up a way to define
> objects that's not more complex than now, but makes inheritance easier,
> I'm all ears.

I'll think about it.  I've not done too horribly much 'C' OO, but once
I'm a bit more familiar with the code maybe something will come to mind.

> >   I'm really new to the code so could be completely off on all of the
> > above, please correct me if I am.
> 
> It sounds like you have a good understanding of the code already, so Iøm
> not too worried.  You may want to code off the DIA_0_94_DEV branch, if
> you're not doing so already.

I was not, I'll do that.

Thanks for the feedback,

-Anthony

PS. was the arrow patch I sent to this list acceptable?  Not sure if
sending to the group was the appropriate thing, but the FAQ seemed to
imply that it was.

-- 
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Anthony Molinaro                                 <anthonym@overture.com>