Text adaptation user to content requirements

From Low Vision Accessibility Task Force

A page to work out the content requirements from the user requirements and issues.

User requirements

User requirements (for text-adaptation) are the ability to:

  • Change the font-family to your preference.
  • Change the foreground/background colors for text.
  • Increase the spacing for text by letter/word/paragraph.
  • Perceive non-text images that are used instead of text (e.g. icons used for buttons)

 Issues found (what actually breaks for users)

Let’s assume the user has the ability to select text-adaptations via a browser extension, the issues found when that is done are:

  1. Unreadable text (either wrapping out of the containing box, or causing boxes to overlap) when a large font-family is selected and/or increased spacing is applied to text for some layouts.
  2. Un-clickable links, when a large font-family is selected and/or increased spacing is applied to text for some layouts.
  3. Icons can become unreadable when colors are changed when they are background-images.
  4. Font-icons disappear when font-family is overridden.
  5. Users have difficulty overriding author inline CSS rules that use !important.
  6. The Stylish addon does not override author inline !important CSS rules.
  7. Text that is hidden with color becomes visible.
  8. Transparent images used for text in controls that depend on a page's background color for visibility become unreadable when background color is overridden.
  9. Background image sprites used for text become unreadable when high contrast mode is enabled.
  10. Text becomes unreadable when author changes foreground color and doesn't change background color.
  11. User adding text in Canvas using a string is not able to be overridden.

@@ Any more??

Content requirements (what authors need to do)

The content requirements could then be (straw man example):

  1. Allow for a 10% buffer on text size within a layout. (#1)
  2. Same as #1.
  3. Use foreground (HTML) image methods such as img / svg, (#3) or
    • Provide fallback. Identify background images that are content in a semantic way so they can be ignored by the user-agent changes. Use James' Icon Font Technique (#3)
  4. Same as #3
  5. Nothing/not applicable: No content requirement as users can override inline !important author CSS rules. Users need to carefully craft their user rules to be at the same or higher specificity level as an author's rules. This necessitates users investigating an author's markup. Check CSS !important Spacing Test (#5)
  6. Nothing/not applicable: No requirement as this is a Stylish bug. The addon applies CSS at document level and not as a true user stylesheet. Check CSS !important Spacing Test(#6)
  7. Same as #10
  8. Same as #3 & #10? Or does this fall under User Interface Component Contrast (Minimum) SC?
  9. Heed F3 (Failure of Success Criterion 1.1.1 due to using CSS to include images that convey important information). (#9)
  10. Heed F24: Success Criterion 1.4.3, 1.4.6 and 1.4.8 due to specifying foreground colors without specifying background colors or vice versa. (#10)
  11. Nothing/not applicable. In the understanding document state that we consider Canvas's implementation of text to be images of text. (#11)

Tracker Issues

LVTF resolutions