Perceivable Techniques

Small Screen Size

• Ensuring that navigation works on different screen sizes (M014)
• Providing vertical navigation mechanisms that work without horizontal scrolling on narrow width screens (M016)
• Providing the open/closed state information in the menu icon (M017)
• Ensure best presentations of captions (either default visible or visible control on mobile) - from Detlev
• size of captions on mobile devices

Zoom/Magnification

• Ensuring that menu can be zoomed to 200% (M018)
  • Menus in particular may present unique challenges when content is magnified to 200%. This may occur because menus often appear vertically and accessing menu items that scroll out of the viewable area may be truncated and/or may present challenges such as menus may disappear when the user scrolls the viewable area.
  • We don't want to imply that 200% is somehow a number that makes it accessible. It's more of a threshold that we have to realistically say once you get to too big you have a very small number of characters or words that appear on the screen so for that reason we don't test above that
• Setting viewport meta setting to allow magnification to 200% (M021)
• Supporting the characteristic properties of the platform (e.g. zoom, larger font, captions) (M007)
  • More applicable to native apps
  • Need to do some more research around media players (caption font sizes)
  • Using Apple system font provides the larger font size in Safari
• Providing a way for users to change font size (M013)
  • Silverlight technique SL23 is related to this one. http://www.w3.org/TR/WCAG20-TECHS/SL23.html
• Ensure snap scrolling does not prevent access to content with resize of text
  • e.g. http://guidobouman.github.io/jquery-panelsnap/
  • Snap scrolling could also potentially affect access to controls to for users with limited mobility.
• Ensure fixed position content does not prevent access to content when text is resized.
  • e.g. www.cnn.com from a device such as an iPhone.

Contrast

Situation A - text is less than 1.5 times default text size or is less than 1.2 times the default text size and bold

• Ensuring that a contrast ratio of at least 4.5:1 exists between text (and images of text) and background behind the text

Situation B - text is 1.5 times default text size or is 1.2 times the default text size and bold

• Ensuring that a contrast ratio of at least 3:1 exists between text (and images of text) and background behind the text

Non Linear Screen Layout

• Managing accessibility for non-linear screen layouts (from Jan) -- to give guidance for very complex mobile pages, including pages that may ignore the DOM, where there is content being swiped in from the sides.
  • Anything working outside the DOM must communicate it to the accessibilityAPI
  • Correct affordances so that people know where there is an operation available from the side swipe
  • Meaningful sequence and focus order with a side swipe - i.e. when menus are swiped in
  • Point of regard - don't lose your current location on main page with a side swipe in/out (i.e. menu swiping in)
  • Considerations for items that steal focus (an advertisement for example). 3.2.1 On Focus 3.2.2 On Input 2.2.2 Pause, stop, hide - auto updating. "If you take an action and a message pops up about that action the message will pop up and become part of the swipe order on that screen – it's something the user initiated but it's not necessarily happening instantly it's happening sometime later - another example is pop up banner ads that you don't want to take focus to, but that's just the way the website works"

Meta

• M19: Providing media metadata
  • Future consideration
  • Check if there is anything in UAAG (Jeanne)