On Mon, 17 Apr 2000, [EMAIL PROTECTED] wrote:
> Alexander Larsson wrote:
>>
>> On Mon, 17 Apr 2000, Arjan J. Molenaar wrote:
>> > I'm quite charmed by the way constraints can solve placement problems,
>> > but since I never did anything using constraints (well, except
>> > programmatical constraints, which are quite inflexible) I'm not sure
>> > where this will end.
>> >
>> > DIA could also benefit from such a canvas, but I don't know when...
>>
>> In such a canvas i don't think constraint solving or even
>> connection-points should be handled. Just generic code for "objects"
>> that can be "drawn" and positioned. Maybe some generic trasformation
>> too. We need to steal some ideas from gnome-canvas, combine with Dia
>> ideas and new ideas and make a perfect canvas.
>
> Again, we see some conflicts because of termonilogy.
>
> In Dia, the grapples/handles uses to resize a widget are call
> connection points.
>
> Suggestion: rename them to grapples
Not quite true. They're called handles. They just happen to coincide with
the connection points in most cases. Connection points are the places that
have little blue crosses and that you can connect the handle of a line to.
> When a edge connect to non-rectangular visual shape, like a losange
> or oval, an obvious problem occur, the grapples do not matches the
> connection points. And peolples complainned of not enough of thoses CP.
I agree with the not enough CP being a problem. Handles not matching CPs
is not a bug, it's a feature. It allows things like the UML Stereotype
object, where the CPs are wastly different from the handles (and rightly
so).
> Even for rectangular shape, edges need to know where they connect,
> may need the help of constraint placement, or visual effect desired.
Some kind of constraint on the connections could solve several problems,
such as ensuring that a line is orthogonal to the object border. It's not
an easy task, though, since the objects would have to provide a lot of info
for the constraints.
-Lars
--
Lars Clausen (http://shasta.cs.uiuc.edu/~lrclause) | H�rdgrim of Numenor
"I do not agree with a word that you say, but I | Retainer of Sir Kegg
will defend to the death your right to say it." | of Westfield
--Evelyn Beatrice Hall paraphrasing Voltaire | Chaos Berserker of Khorne
