[Kde-accessibility] Re: [Kwin] Size of window borders

Bill Haneman Bill.Haneman at Sun.COM
Tue Sep 16 14:24:00 CEST 2003


I have a couple of observations about this issue, regarding window
border sizing and accessibility.

First, I don't think continuously-variable sizes are really a
requirement; the maximum implemented size is the most important point. 
Having each size (if you use fixed sizes) no more than about 50% bigger
than the next-largest size gives a pretty good range.

If you really want to support a wide range for accessibility reasons,
you may find that changing the rendering implementation slightly will
give the best results, without requiring theme authors to create
decorations at a large number of sizes.  If you can only render
decorations at, say, 40 pixels if the theme creator supports 40 pixel
wide decorations, you will find that lots of themes don't work with your
"accessible" configurations.

By changing the rendering implementation, I mean doing something like
this for decorations (both those composed of graphics primitives and
those using bitmaps): pick the "best" or "nearest" size to the target
size from those available, render, then rescale the result to the target
size.  You can cache the result if performance is a concern, for
instance in drawing window "buttons", etc.  The sizes for which a theme
author has optimized will look best, but other sizes will look OK too,
if slightly less sharp because of the rescaling.  Sharpness is often not
an issue for users who need really big borders, so this is probably
acceptable.

A few new lines of code in the kwin renderer could prevent the need for
window theme creators to support a large number of border sizes
directly.

- Bill

On Tue, 2003-09-16 at 13:17, Lubos Lunak wrote:
> On Tuesday 16 of September 2003 13:48, Gunnar Schmi Dt wrote:
> > -----BEGIN PGP SIGNED MESSAGE-----
> > Hash: SHA1
> >
> > Hello,
> >
> > On Tuesday 16 September 2003 12:59, Lubos Lunak wrote:
> > > On Tuesday 16 of September 2003 11:06, Luciano Montanaro wrote:
> > > > On Monday 15 September 2003 12:46, Gunnar Schmi Dt wrote:
> [snip]
> > > >
> > > > On the other hand, the "fixed setting" is not meant to be fixed at all,
> > > > it is just a hint to the decoration that "normal" or "big" or "huge"
> > > > borders are requested. If a decoration "normal" border is 3 pixels, a
> > > > "huge" border could be, let's say 24 pixels, but it is up to the
> > > > decoration writer to choose the exact size.
> > >
> > >  Agreed. Moreover, I expect that most decorations will implement only few
> > > sizes at most anyway, as they use pre-made pixmaps for the decoration
> > > buttons, and I don't think their developers will bother with scaling them
> > > to 10 different sizes.
> >
> > This "agreed" belongs to which statement?
> 
>  To the paragraph is left above.
> 
> > As I wrote in my answer to the
> > mail from Luciano having only five different sizes creates problems, so I
> > would suggest to either have a slider or to have some more standard sizes.
> > Also these standard sizes should include a recommended border width (well,
> > it is up to the decoration to follow that recommendation or not).
> >
> > >  Currently, there are these options: BorderTiny, BorderNormal,
> > > BorderLarge, BorderVeryLarge, BorderHuge. It's up to the decoration to
> > > decide what this means in terms of pixel sizes, it's only said that
> > > BorderNormal is the normal size. I can add more values, if you want (and
> > > suggest names for them), but I personally doubt having 10 levels makes
> > > sense.
> >
> > What about:
> > Tiny (3 pixels)
> > Small (5 pixels)
> > Medium (8 pixels)
> > Large (12 pixels)
> > Very Large (17 pixels)
> > Huge (23 pixels)
> > Very Huge (30 pixels)
> > Oversized (38 pixels)
> 
>  Well, I can add those 3 more possibilities if you think it makes sense (as I 
> already said, I expect most decorations not to support so many different 
> sizes, so this would be IMO only for the decorations where the developer will 
> bother will all the required scalling).
> 
>  I have two questions though:
> - To which size are those pixel values supposed to refer? Are those pixel 
> sizes supposed to be width of left/right borders? In which case current 
> decorations mostly have Tiny borders, which probably isn't right. Or is it 
> supposed to be the titlebar? In which case current decorations have roughly 
> VeryLarge borders, which I think isn't right either.
> - Second question is actually closely related to the first one: Which setting 
> should be the default one, i.e. the size decorations have now?
> 
> -- 
> Lubos Lunak
> KDE developer
> ---------------------------------------------------------------------
> SuSE CR, s.r.o.  e-mail: l.lunak at suse.cz , l.lunak at kde.org
> Drahobejlova 27  tel: +420 2 9654 2373
> 190 00 Praha 9   fax: +420 2 9654 2374
> Czech Republic   http://www.suse.cz/
> 
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