RE: Adapting Text Units: Spaces, paragraphs, and ems

If paragraph spacing must be included, then we can do it as a factor on font size just like the rest, although it will have ambiguity as to which “paragraph’s” font size to use along with much more…

I purposely did not include it because of all the other layout questions it raises, and the fact that we’d need a clear definition for paragraph spacing.  I’m sorry but it’s just nowhere near as testable as the other 3 bullets.  Here’s some questions we should be prepared to deal with:

1.       Which paragraph’s font size do I base the spacing on?

2.       Is it spacing before or after or split between the two?

3.       Does a heading or sub-heading count as a paragraph?  Seems like that would be a much bigger distinguisher so I’m assuming no.

4.       What if a list, block quote, image, or other element breaks up a paragraph?  This becomes an important difference depending on the answers to 1 and 2.

5.       If a paragraph has another visual distinction like a first line indent or border, is the spacing requirement the same?

In the end though, I’m having a tough time seeing how a test for paragraph spacing could ever really fail in the context of this criterion, and what CSS rules would be used to test it that didn’t make a lot of assumptions on tags used by the author.  For example, if I start with a typical site with no negative margins and no absolutely positioned elements, then what possible content or functionality could be lost by applying:

p + p {margin-top: 1em}
p ~ p {margin-bottom: 1em}

The other 3 bullets are important because they affect the content within the element and thus how it is sized is being tested.  What is being tested with paragraph spacing?

Steve


From: Katie Haritos-Shea [mailto:ryladog@gmail.com]
Sent: Wednesday, July 12, 2017 2:23 PM
To: Laura Carlson <laura.lee.carlson@gmail.com>
Cc: John Foliot <john.foliot@deque.com>; public-low-vision-a11y-tf <public-low-vision-a11y-tf@w3.org>; Jason White <jjwhite@ets.org>; w3c-wai-gl@w3.org; Alastair Campbell <acampbell@nomensa.com>; Detlev Fischer <detlev.fischer@testkreis.de>; Repsher, Stephen J <stephen.j.repsher@boeing.com>; Greg Lowney <gcl-0039@access-research.org>
Subject: Re: Adapting Text Units: Spaces, paragraphs, and ems

+1 to Stephens technology agnostic language approach.

Awesome work Wayne, Alistair, Laura etc all...
Katie Haritos-Shea
703-371-5545

On Jul 12, 2017 2:11 PM, "Laura Carlson" <laura.lee.carlson@gmail.com<mailto:laura.lee.carlson@gmail.com>> wrote:
Hi Steve,

How would you propose to phase new paragraph bullet using font size?
Lisa has objected to inclusion of the Adapting Text SC in 2.1 without
it.

Thanks.

Kindest Regards,
Laura

On 7/12/17, Repsher, Stephen J <stephen.j.repsher@boeing.com<mailto:stephen.j.repsher@boeing.com>> wrote:
> We’re not being technology agnostic here.  The truth is that the only reason
> we are drawing a difference between em units and a unitless factor on the
> font size is technology-specific to CSS.  In reality they are exactly the
> same, i.e. for the current element:
>
> `Line-height: 1.5` = `line-height: 1.5em`
>
> The problem is that these are inherited properties, so a length value in em
> passes the same computed length to children, while the factor becomes a
> factor on the child’s font size.  Obviously the latter is usually the
> desired behavior.  Why the CSS standard doesn’t also allow factors to be
> used for `letter-spacing` and `word-spacing` is a good question.
>
> So, to be totally technology agnostic here, we ought to pick one and be
> consistent.  Given the confusion that could arise by specifying inheritance
> with em units, I’d strongly vote for the following:
>
>
> 1.       line height (line spacing) to at least 1.5 times the font size
>
> 2.       letter spacing (tracking) to at least 0.12 times the font size
>
> 3.       word spacing to at least 0.16 times the font size
>
> We can explain what this translates to for CSS in Understanding, which is
> advantageous in case things change.
>
> Steve
>
> From: Alastair Campbell [mailto:acampbell@nomensa.com<mailto:acampbell@nomensa.com>]
> Sent: Wednesday, July 12, 2017 12:17 PM
> To: John Foliot <john.foliot@deque.com<mailto:john.foliot@deque.com>>
> Cc: Laura Carlson <laura.lee.carlson@gmail.com<mailto:laura.lee.carlson@gmail.com>>; Greg Lowney
> <gcl-0039@access-research.org<mailto:gcl-0039@access-research.org>>; Jason White <jjwhite@ets.org<mailto:jjwhite@ets.org>>; Detlev
> Fischer <detlev.fischer@testkreis.de<mailto:detlev.fischer@testkreis.de>>; w3c-wai-gl@w3.org<mailto:w3c-wai-gl@w3.org>;
> public-low-vision-a11y-tf <public-low-vision-a11y-tf@w3.org<mailto:public-low-vision-a11y-tf@w3.org>>
> Subject: Re: Adapting Text Units: Spaces, paragraphs, and ems
>
> That’s fine for me, thanks.
>
> Any objections? Going, going…
>
> -Alastair
>
>
> From: John Foliot
>
> Hi Alastair,
>
> A bit more fine-tuning... how about:
>
> * line-height (spacing) to at least 1.5 em (space line-and-a-half)
> * spacing between paragraphs to at least 2 em (2 lines)
>
> * letter spacing (tracking) to at least 0.12 em
> * word spacing to at least 0.16 em
>
> ???
>
> JF
>
>


--
Laura L. Carlson