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
|
