Ross,
You can find the CSS2 specification at
http://www.w3.org/TR/REC-CSS2/
This is a W3C recommendation, but the actual implementation is up
to browser manufacturers. I know that all current versions of Internet
Explorer support nearly all of CSS2, but that Netscape 6 doesn't. I
haven't checked with Mozilla or Netscape 7.
Denis Anson, MS, OTR
Computer Access Specialist
College Misericordia
301 Lake St.
Dallas, PA 18612
email: [log in to unmask]
Phone: 570-674-6413
> -----Original Message-----
> From: * EASI: Equal Access to Software & Information
> [mailto:[log in to unmask]] On Behalf Of Ross Eadie
> Sent: Tuesday, October 29, 2002 12:41 AM
> To: [log in to unmask]
> Subject: Re: Question about absolute vs. relative sizes
>
> Your trust is safely placed. I spend a lot of time thinking
about
> the
> visual appeal of all my documents and such things. Graphics
> properly used
> make things much easier to understand. On the topic of CSS, I
did
> not find
> a 2.X spec last time I checked the W3 site and other links
about 7
> or 8
> months ago. Where might I find the 2.X spec, and is it stable?
>
> At 01:39 PM 10/28/02 , you wrote:
> > There are actually two "relative" issues being dealt
with
> here,
> >which may be part of the confusion. When a page is laid out
using
> >relative proportions, the size of table cells or graphical
elements
> will
> >automatically change with the size or resolution of the
display
> screen.
> >If one viewer looks at the page with a 17 inch monitor set to
> 1024x768
> >resolution, and another views it with a 13 inch monitor and
640x480
> >resolution, you can assure that the text occupies the same
> proportion of
> >the visible screen. This is considered good practice, because
your
> >table won't hang off the side of the small screen, requiring
> frequent
> >scrolling.
> >
> > The em and ex elements don't scale with the screen
size, but
> with
> >the font size. If I need to have a larger font on the screen
> because of
> >low vision, the relative size of margins and some in-line
graphics
> need
> >to change to accommodate that change. For example, I use a
CSS
> >"drop-cap" on some of my pages, and that should change in
> proportion to
> >the text around it so that the overall layout remains the
same.
> >
> > So, tables and graphics have a relative measure that is
> based on
> >the size of the screen, and in-line elements have a relative
> measure
> >that is a function of the font size that is around them, and
to
> some
> >extent, to the font, since the proportion of ex height to em
height
> >differs between fonts.
> >
> > I trust you were being facetious about not caring about
> border
> >widths, because you were blind. That is the mirror of the
attitude
> that
> >has led to so many inaccessible pages. "I can see, so I don't
care
> >about blind access." When we design pages, they aren't for
*us* to
> look
> >at, but for our audience.
> >
> > Denis Anson, MS, OTR
> > Computer Access Specialist
> > College Misericordia
> > 301 Lake St.
> > Dallas, PA 18612
> > email: [log in to unmask]
> > Phone: 570-674-6413
> >
> >
> > > -----Original Message-----
> > > From: * EASI: Equal Access to Software & Information
> > > [mailto:[log in to unmask]] On Behalf Of Ross
> Eadie
> > > Sent: Monday, October 28, 2002 12:37 PM
> > > To: [log in to unmask]
> > > Subject: Re: Question about absolute vs. relative
sizes
> > >
> > > I am by no means an expert, but It would seem to me
that
> >elements
> > > related
> > > to the spacial layout of the screen should be created
by
> using
> > > percentages.
> > > I think you might be getting confused with the
dynamic
> >relationship
> > > of
> > > relative percentages of the screen verses the affect
a
> screen
> >size
> > > can have
> > > on an element using pixcel size. On the other hand,
> someone
> >could
> > > make the
> > > pixcel size relative to the screen pixcel size
variable if
> one
> >can
> > > create a
> > > script or program to extract that information from
every
> user
> >agent
> > > hitting
> > > the page. I am not overly familiar with CSS 2.? or
1.0
> for
> >that
> > > matter.
> > > Does it provide a utility to extract the screen size
> variable
> >from a
> > > user
> > > agent's computer? It is just so much easier to use
> >percentages.
> > > As for using pixcel size for borders and similar
elements,
> I
> >would
> > > suggest
> > > the element use dynamic relative measurements as well
to
> avoid
> > > visual
> > > distortions. I am totally blind, and I honestly
don't
> care
> >about
> > > the size
> > > of borders anyway <grin>.
> > >
> > > At 09:18 AM 10/28/02 , you wrote:
> > > >Hello EASI Colleagues,
> > > >
> > > >I would appreciate hearing comments from web
> accessibility
> >experts
> > > on this
> > > question I received from a web developer who is
> retrofitting a
> >site.
> > > >
> > > >Alan
> > > >
> > > >The question:
> > > >
> > > >Which length measurements are relative?
> > > >
> > > >The WAI examples list percentages (%) and em (base
font
> >height) as
> > > examples of relative length measurements (slide 32).
BUT,
> the
> >CSS1
> > > and CSS2
> > > >specifications also list ex (the x-height) and px
> (pixels)
> > > >as relative measurements. "px" is relative because
> > > >
> > > ><blockquote>
> > > >Pixel units are relative to the resolution of the
viewing
> >device,
> > > i.e.,
> > > most often a computer display. If the pixel density
of the
> >output
> > > device is
> > > very different from that of a typical computer
display,
> the
> >user
> > > agent
> > > should rescale pixel values. It is recommended that
the
> >reference
> > > pixel be
> > > the visual angle of one pixel on a device with a
pixel
> density
> >of
> > > 90dpi and
> > > a distance from the reader of an arm's length. For a
> nominal
> >arm's
> > > length
> > > of 28 inches, the visual angle is therefore about
0.0227
> >degrees.
> > > (CSS2 spec)
> > > >
> > > ></blockquote>
> > > >
> > > >Since the pixel is defined in terms of a visual
angle and
> a
> > > distance,
> > > isn't it really an absolute value just like in
(inches) or
> cm
> > > (centimetres)? Also, it's not resizeable by the user
like
> font-
> > > relative
> > > measurements are, is it?
> > > >
> > > >On the other hand, it's very useful for defining
things
> like
> > > border-width
> > > or image sizes. Is it OK (i.e. accessible) to use px
for
> >certain
> > > properties
> > > and not for others?
> > > >
> > > >
> > > >
> > > >Alan Cantor
> > > >Project Manager
> > > >Strategic e-Government Implementation
> > > >e-Government, OCCS
> > > >416-212-1152
> > > >[log in to unmask]
> > > >
> > > ---
> > > Ross Eadie
> > > Voice: (204) 339-5287
> >
> ---
> Ross Eadie
> Voice: (204) 339-5287
|
