[cad-linux-dev] Re: braindead gui toolkits
- From: phrostie <pfrostie@xxxxxxxxx>
- To: cad-linux-dev@xxxxxxxxxxxxx
- Date: Fri, 29 Oct 2004 07:47:24 -0700 (PDT)
I've played with a number of IDEs for building GUIs and the easiest for me was
Visual-TCL also known as V-TCL. not familiar with Zinc, but just want to say
think you for not binding this with KDE/Gnome. things(building/distributing)
always get too complicated with you start down that path.
--- Eric Wilhelm <ewilhelm@> wrote:
> Ok, I'm just coming out of the woods with my adventures in Tk::Zinc.
> The text zooming did indeed work out, but it took some juggling to
> get from a "height" to a "font" (and that font is currently
> hard-coded.) If you're feeling adventurous, feel free to dig into
> the subversion repository.
> http://ericwilhelm.homeip.net/svn/CAD-Drawing/trunk/code/CAD/Drawing/
>
> Sorry, no tarballs yet. Maybe once it's seen some use I'll put it on
> CPAN.
>
> Some interesting issues come up in how to create keybindings between
> multiple windows. For instance, the zoom function. The "z" key
> activates zoom from any toplevel widget, but which canvas should it
> put that functionality into? My solution is "all of them". The
> problem then is how to tell the other canvases that you are done
> zooming (and that therefore they should be too.) This leads to the
> sharing of the functionality CAD::Drawing::GUI and
> CAD::Drawing::GUI::View modules. The GUI module handles the
> management of multiple canvases, while the View object is a single
> canvas (though it has to have the same drawing on it, scale and etc
> are independent.)
>
> As for the braind-dead-ness. I looked at GTK, QT, TK, WX, and finally
> ended up with Tk::Zinc because it was the only one that was able to
> scale text without having to do the recalculate-approximate dance
> (which leads to really bumpy zooming when you have to jump from 12pt
> to 24pt.)
>
> So, why are we using points to describe text in a world of pixels?
>
> Furthermore, why does the y-axis have to point downward? Sure, that's
> how X works, but isn't the point of toolkits to make programming
> easier? Am I thinking upside-down, or is that everyone else?
>
> Finally, what's with the rectangles? Okay, a rectangle can be
> described with two points, but it's just a special case of a
> polyline. A circle usually doesn't have it's own method (we have to
> call it an arc), so why rectangles? On top of that, we describe said
> rectangles as a list of four points?! Isn't it a pair of pairs?
>
> While I'm at the rectangles, why are arcs and elliptical arcs
> described as fitting inside of a rectangle? At least with Tk::Zinc,
> I can apply rotation afterwards (to get a slanted elliptical arc
> (though that makes for some hairy math), but Tk and Wx also suffer
> from the rectangular world syndrome and don't seem to have a way to
> rotate entities.
>
> Is there not any demand for these things? I just want a right-side-up
> canvas with arcs described by a center and radius, scalable
> pixel-sized text, and the ability to draw angled elliptical arcs.
>
> It's getting to the point where I just want to abandon most of the API
> and draw everything as bezier curves. Of course, the slow-down of
> evaluating these curves in Perl would not be fun.
>
> On a more upbeat note, working on this did give me an idea for a
> cadfs-based toolkit. Basically, this would be like Draft in that it
> immediately displays what happens in the database. However, to be
> able to repurpose (embed, etc) it for other applications, you would
> want a way to bind callbacks and such to this gui (particularly, a
> way for those callbacks to involve multiple viewports, etc.)
> Unfortunately, my latest effort is attached to the aging CAD::Drawing
> data-structure, but the concepts could easily be re-attached to
> something else (and should maybe be done so in a compiled language.)
>
> --Eric
> --
> "Left to themselves, things tend to go from bad to worse."
> --Murphy's Corollary
Given any mechanical device and the probablity for error to occure.
as long as all component are proportionally in error, then the device will
continue to funtion in a normal manor.
or as my father would say, make it fit.
>
=====
phrostie
Oh I have slipped the surly bonds of DOS
and danced the skies on Linux silvered wings.
http://pfrostie.freeservers.com/cad-tastrafy/
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