Text Size (LV)

[allanj-uaag]

SC Shortname

Text Size

SC Text

Except for images of text, text can be resized without assistive technology up to the user agent maximum without loss of content and functionality.

Current WCAG 1.4.4

Except for captions and images of text, text can be resized without assistive technology up to 200 percent without loss of content or functionality.

Proposed Change:

Except for captions and images of text, text can be resized without assistive technology up to 200 percent @@the user agent maximum without loss of content and functionality@@.

Suggested Priority Level

Level A

Related Glossary additions or changes

None

What Principle and Guideline the SC falls within.

Principle 1, Guideline 1.4.4 Resize text

Description

A person can increase or decrease text-size only. Non-text content does not change. A key functionality to preserve is that complete lines of text fit within the viewport. For any block of text, the last word of a line is the immediate predecessor of the first word in the next line in reading order. No exceptions. Also, text fits within bounding boxes, lines, and columns if present. Finally, margins should not change with text size.

Benefits

Some people need larger text in order to perceive letters. Although increasing size is most common, some people with tunnel vision and good visual acuity may prefer smaller letters so they can see more words at a time.

Example issues:

• Text settings don't increase the text in tool-tip text and other pop-up text
• Text settings don't increase the text in images
• Text settings don't increase the text in maps

User Need - Text Size: Users can change the text size (font size) of all text, without zooming the entire interface. - Source: Accessibility Requirements for People with Low Vision, Section 3.3.1: text size

Testability

1. Display content in a user agent.
2. Increase text size to the maximum.
3. Check whether text scales and is perceivable.

Expected Results

• Check New SC proposal: After initial page load, programmatic notification is provided for each visual indicator that content is loading or the page is busy. #3 is true.

Techniques

All Existing Techniques for Changed SC

• C28: Specifying the size of text containers using em units (CSS)
• Techniques for relative measurements
  • C12: Using percent for font sizes (CSS)
  • C13: Using named font sizes (CSS)
  • C14: Using em units for font sizes (CSS)
  • C22: Using CSS to control visual presentation of text

New Techniques

• Ensuring that there is no loss of content or functionality when the text resizes and text containers do not change when resized up to user agent maximum. To be based on G179, which is currently limited to a 200% maximum.
• Failure of Success Criterion 1.4.4 when resizing visually rendered text up to user agent maximum causes the text, image or controls to be clipped, truncated or obscured. To be based on F69, which is currently limited to a 200% maximum.

Related Information

Actions

• ACTION-76: When users change font size and list out the cases for the sc on Scott McCormack, August 25, 2016

Articles

• Font size - Education and Outreach Working Group Tutorial

Email

• Text Size - Wayne Dick, 14 September 2016
  • Re: Text Size Jim Allan, 14 September 2016
  • Text Size SC - Wayne Dick, 14 September 2016
• Thread: Re: lvtf-ACTION-70: Write font sc - LVTF List
• Thread: 1100% may be physically impossible and still not achieve the results on smaller monitors - WCAG WG List
• Thread: 1100% enlargement - LVTF List
• Thread: lvtf-ACTION-70: Write font sc - LVTF List
• Requirements doc - Alastair Campbell, 18 February 2016

GitHub

• WCAG 1.4.8 item 5 200% #5 LVTF GitHub SC Issue #5
• Text Size (User Need 3.3.1) - LVTF GitHub SC Issue #14

Minutes

• 15 September 2016 LVTF minutes
• 5 May 2016 LVTF minutes
• 19 May 2016 LVTF minutes
• 1 September 2016 LVTF minutes

Wiki Pages

• Use cases - LVTF Wiki

[DavidMacDonald]

"up to 200 percent @@the user agent maximum"

Huh? How can you exceed the user agent maximum with the user agent? Do you mean "OR"?

[jnurthen]

Can someone explain how stating that it has to work up to the user agent maximum works in practice? If I develop content which conforms and then someone develops or extends a user agent which allows a greater zoom level and now my content fails despite it being the same?
I don't think I can support this without there being a specific zoom level specified.

Regards,
James.

On Nov 10, 2016, at 16:57, David MacDonald [email protected] wrote:

"up to 200 percent @@the user agent maximum"

Huh? How can you exceed the user agent maximum with the user agent?

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[alastc]

I think this one is defunct, the Resize all content and Reflow should cover the same use-cases and are (more) testable.

[allanj-uaag]

closed covered by #58 and #77