Re: Motivation for having a 'text color' that is invisible

[Lars Clausen <lars raeder dk>]

On Sat, 2007-10-27 at 22:03 +0530, Sameer Sahasrabuddhe wrote:
> On 10/27/07, Lars Clausen <lars raeder dk> wrote:
> > So invisible (as opposed to transparent) text would not be counted
> > towards diagram extents?  If that's not the point, I don't know what
> > there is to toggling visibility that transparency doesn't handle.
>
> Invisible, undisplayed, unrendered, transparent ... it's getting a bit
> confusing here! :)

Now I'm suddenly undecided whether transparent should be part of the
color system or separate.  I think I prefer having it as part of
coloring, since it then can be applied to all colored objects without
having to add significant fluff to the UI.

> By "diagram extents", are you referring to objections that I raised in
> another mail, about mysterious blank areas that will show up?

Yes.

> Having a toggle is a big deal ... the text, or a part of an object in
> general, is "not present" at all in that instance of the object. It
> never reaches the renderer(s), nor does it show up when calculating
> the size of a group, or when aligning multiple objects. (I don't know
> enough about Dia in terms of how rendering really works). Such a
> toggle ensures that the "disabled part" is not counted in all those
> operations.

It would indeed have to happen at a very different level.  Both
approaches have their uses, I'd say the transparent color would be
easier to fit into the current UI, as it doesn't require an extra toggle
button for all manner of things, and it's probably also easier to code.

For clarity, then: "transparent" means a color setting, while
"undisplayed" means that the (part of the) object is not considered to
exist for any calculations at all, including bounding box, diagram
extends, parenting etc.

-Lars