Re: Update to 1.4.12 Text Spacing Understanding

Hi Jim,

Is there any distinction to be made between “user interface text” and “body / content text”?  I’m thinking here of web-apps (and non-Web ICT).  Imagine a typical menu “File  Edit  View” etc.  There are no paragraphs of text, or even sentences.


Regards,

Peter
--
Peter Korn | Director, Accessibility | Amazon Lab126
pkorn@amazon.com

From: Jim Allan <jimallan@tsbvi.edu>
Date: Thursday, August 8, 2019 at 9:47 AM
To: WAI-GL <w3c-wai-gl@w3.org>, public-low-vision-a11y-tf <public-low-vision-a11y-tf@w3.org>
Subject: Update to 1.4.12 Text Spacing Understanding
Resent-From: <w3c-wai-gl@w3.org>
Resent-Date: Thursday, August 8, 2019 at 9:44 AM

All,
A few weeks ago LVTF was asked our opinion on 1.4.12 wording change. We thought the current wording was fine and that expanding the Understanding document would bring some clarity to the issue. Below are the original understanding sections followed by the updated sections with changes in bold(@). There were some spelling corrections and some deletions. Attached is the track changes view in word format.

Intent

The intent of this Success Criterion (SC) is to ensure that people can override text spacing to improve their reading experience. Each of the requirements stipulated in the SC's four bullets helps ensure text styling can be adapted by the user to suit their needs.

This SC focuses on the ability to increase spacing between lines, words, letters, and paragraphs. Any combination of these may assist a user with effectively reading text. As well, ensuring users can override author settings for spacing also signficantly increases the likelihood other style preferences can be set by the user. For example, a user may need to change to a wider font family than the author has set in order to effectively read text.

Author Responsibility

This SC does not dictate that authors must set all their content to the specified metrics. Rather, it specifies that an author's content has the ability to be set to those metrics without loss of content or functionality. The author requirement is both to not interfere with a user's ability to override the author settings, and to ensure that content thus modified does not break content in the manners shown in figures 1 through 4 in Effects of Not Allowing for Spacing Override.

Applicability

If the markup-based technologies being used are capable of overriding text to the Success Criterion's metrics, then this SC is applicable. For instance Cascading Style Sheet/HTML technologies are quite able to allow for the specified spacing metrics. Plugin technologies would need to have a built-in ability to modify styles to the specified metrics. Currently, this SC does not apply to PDF as it is not implemented using markup.

Examples of text that are typically not affected by style properties<https://www.w3.org/WAI/WCAG21/Understanding/text-spacing.html#dfn-style-property> and not expected to adapt are:
·         Video captions embedded directly into the video frames and not provided as an associated caption file
·         Images of text<https://www.w3.org/WAI/WCAG21/Understanding/text-spacing.html#dfn-image-of-text>

For this SC, canvas<https://www.w3.org/TR/html5/scripting-1.html#the-canvas-element> implementations of text are considered to be images of text<https://www.w3.org/WAI/WCAG21/Understanding/text-spacing.html#dfn-image-of-text>.

User Responsibility

The ability to read and derive meaning from the overridden spacing rests with the user. If the increased spacing impacts those abilities, the user will adjust or they will return to the default view. Regardless, the user needs the flexibility to adjust spacing within the bounds set in the SC. Such changes may be acheived via user stylesheet, bookmarklet, extension, or application.

-------------

Updated Understanding
Intent
The intent of this Success Criterion (SC) is to ensure that people can override @author specified@ text spacing to improve their reading experience. Each of the requirements stipulated in the SC's four bullets helps ensure text styling can be adapted by the user to suit their needs.
@The specified metrics set a minimum baseline. The values in between the author's metrics and the metrics specified in this SC should not have loss of content or functionality.@

This SC focuses on the ability to increase spacing between lines, words, letters, and paragraphs. Any combination of these may assist a user with effectively reading text. As well, ensuring users can override author settings for spacing also significantly increases the likelihood other style preferences can be set by the user. For example, a user may need to change to a wider font family than the author has set in order to effectively read text.

Author Responsibility
This SC does not dictate that authors must set all their content to the specified metrics. Rather, it specifies that an author's content has the ability to be set to those metrics without loss of content or functionality. The author requirement is both to not interfere with a user's ability to override the author settings, and to ensure that content thus modified does not break content in the manners shown in figures 1 through 4 in Effects of Not Allowing for Spacing Override. @The values in the SC are a baseline. We want to encourage authors to surpass these, not see them as a ceiling to build to. If the user chooses to go beyond the SC’s metrics any resulting loss of content or functionality is the users responsibility.@
Applicability
If the markup-based technologies being used are capable of overriding text to the Success Criterion's metrics, then this SC is applicable. For instance Cascading Style Sheet/HTML technologies are quite able to allow for the specified spacing metrics. Plugin technologies would need to have a built-in ability to modify styles to the specified metrics. Currently, this SC does not apply to PDF as it is not implemented using markup.
Examples of text that are typically not affected by style properties<https://www.w3.org/WAI/WCAG21/Understanding/text-spacing.html#dfn-style-property> and not expected to adapt are:
•         Video captions embedded directly into the video frames and not provided as an associated caption file
•         Images of text<https://www.w3.org/WAI/WCAG21/Understanding/text-spacing.html#dfn-image-of-text>
For this SC, canvas<https://www.w3.org/TR/html5/scripting-1.html#the-canvas-element> implementations of text are considered to be images of text<https://www.w3.org/WAI/WCAG21/Understanding/text-spacing.html#dfn-image-of-text>.

User Responsibility
The ability to read and derive meaning from the overridden spacing rests with the user. @The user may choose to exceed the spacing adjustments in the SC. If the increased spacing causes loss of content or functionality, the user will adjust or return to the author’s original spacing or spacing within the bounds of the SC.@ Regardless, the user needs the flexibility to adjust spacing within the bounds set in the SC@ without loss of content or functionality.@ Such changes may be achieved via user stylesheet, bookmarklet, extension, or application.


--
Jim Allan, Accessibility Coordinator
Texas School for the Blind and Visually Impaired
1100 W. 45th St., Austin, Texas 78756
voice 512.206.9315    fax: 512.206.9452 http://www.tsbvi.edu/

"We shape our tools and thereafter our tools shape us." McLuhan, 1964