Engineering Technology

1

• Accessibility
• What ?...
• Why ?...
• ?

2
Multimedia Accessibility

• Accessibility is not only a problem of the web
• Any multimedia artifact has the same problem.
• Design is about solving problems!
• Nothing - exists in a vacuum Think about it

3
Multimedia Accessibility

• Accessibility is one of the prime functions of
  HCI
• HCI is based around making a system user centred.
• Whatever the system it is the interface which
  communicates to the user.

4
Multimedia Accessibility

• For a number of years accessibility has
  been progressively built into main operating
  systems, including browsers
• and design applications.

5
Multimedia Accessibility

• The alt command has been an integral aspect of
  HTML tags since JavaScript and Jscript. It is
  even incorporated into Dreamweaver
• ltimg src"Images/Interactive.gif" width"324"
  height"74" border"0" alt"Interactive Image
  Button"gt
• Accessibility1No.htm
• Accessibility2yes.htm

6
Accessibility Strategies

• Hearing disabilities
• Provide synchronized captions for any audio
  that conveys content
• Photo epilepsy
• Remove strobing content that flashes between 2
  and 55 times per second
• Motor disabilities
• Ensure the Flash content is keyboard accessible
• Do not require fine motor skills

7
Accessibility Strategies

• Cognative disabilities
• Give users control over time sensitive content
• Be consistent
• Use the clearest, simplest language appropriate
• Low vision
• Provide plenty of contrast
• Allow Flash content to scale
• Blindness
• Ensure screen reader accessibility or
  alternative!
• Ensure keyboard access
• Provide dynamic text equivalent for non-text
  objects

8
Accessibility - Flash

• In Flash MX 2004, a new set of Flash interactive
  components are now available
• Simple Button
• Check Box
• Radio Button
• Label
• Text Input
• Text Area
• Combo Box
• List Box
• Window
• Alert
• Data Grid

9
Accessibility - Flash

• Flash already has the ability to create
  accessible material without screen readers and
  the like.
• Flash gives you control
• Over keyboard events
• Over mouse events
• Over sound
• Over dynamic text

10
Accessibility - Flash

• To add a text equivalent, select an item on the
  stage and enter a short description of the object
  into the Name text box on the Accessibility
  panel. If a longer description is needed, it can
  be added to the Description field on the
  Accessibility panel. The screen reader will now
  read this text in place of the object.

Window Menu gt Accessibility
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Accessibility - Flash
12
Accessibility - Flash

• If it is appropriate, you can easily provide a
  text equivalent for your entire movie, rather
  than worrying about trying to get individual
  parts of the movie to be accessible.
• This would be similar to providing an alternative
  text for an entire Web page.

13
Accessibility - Flash

• Just deselect everything on the Flash stage,
  select the Accessibility panel, and deselect Make
  Child Objects Accessible to hide the internal
  contents of the movie.
• Then deselect Auto Label and
• add a brief Name and if needed,
• a longer Description.

14
Accessibility - Flash

• Detecting screen readers
• Perhaps you want to provide a different Flash
  interface or options if a user is using a screen
  reader.
• For instance, you may want to provide additional
  buttons or turn on self-voicing features when the
  person watching your movie is using a screen
  reader. You can detect screen readers using
  ActionScript.

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Accessibility - Flash

• Detecting screen readers
• The Accessibility.isActive() function will
  return "true" if a screen reader that is capable
  of accessing Flash content is detected (currently
  only up-to-date versions of Window-Eyes and
  Jaws). For instance, you might add
• if (Accessibility.isActive())   
  _root.selfVoicing.play()

16
Accessibility - Flash

• Detecting screen readers
• if (Accessibility.isActive())   
  getURL(screenreaderpage.htm) else   
  getURL(normalpage.htm)

17
Accessibility - Flash

• Keyboard Accessibility
• Unless you are using version 7 of the Flash
  player in Internet Explorer for Windows, when
  Flash receives the focus within a Web page, it
  maintains that focus.
• What this means is that once you click in or tab
  to a Flash movie, you cannot use the keyboard to
  navigate to other items on the page.

18
Accessibility - Flash

• Keyboard Accessibility
• The screen readers that support Flash (current
  versions of JAWS and Window-Eyes) have built in
  functionality that will change focus back to the
  Web page after all of the Flash items have been
  accessed.
• Common browsers with older versions of the Flash
  player, however, do not have this functionality.

19
Accessibility - Flash

• Keyboard Accessibility
• Those using Mozilla, Netscape 7, or Opera will
  notice that the Flash content is skipped entirely
  when navigating with the Tab key (or Q and A keys
  in Opera).

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Accessibility - Flash

• Keyboard Accessibility
• To access the elements within the Flash movie
  with these browsers, the user must use the mouse
  to click within the movie. At this point, you
  will then no longer be able to navigate outside
  of the Flash movie without using the mouse.
• This can be an issue for people with motor
  disabilities that must use the keyboard for
  navigation.

21
Accessibility - Flash

• You can alleviate this by placing the movie in
  a Web page by itself so that there is no need to
  navigate to other items within the page.
• If the movie is on a Web page with other
  elements, you could make the movie invisible to
  the Web browser or set all of the buttons in the
  movie to be inaccessible in the Accessibility
  panel.

22
Accessibility - Flash

• However, both of these options make the movie
  itself inaccessible to the keyboard and should
  only be used if an HTML alternative is provided
  or if the movie does not contain important
  content or functionality.

23
Accessibility - Flash

• Hot spots are dealt with in the same way as
  image objects
• Scaling content
• Because Flash is vector based, it can be easily
  resized and maintain its original look. Vector
  elements do not pixelate and can be infinitely
  enlarged on a screen without losing their shape
  or quality.

24
Accessibility - Flash

• Scaling content
• This feature is very useful to individuals with
  low vision. When possible, allow your Flash
  content to automatically scale to a percentage
  value of the browser width and height rather than
  specifying specific pixel values for width and
  height.
• This allows the content to be enlarged as the
  Web page is enlarged in browsers and assistive
  technologies that provide this functionality.

25

• Other considerations
• some Flash content, including banners ads or
  page decorations are often not necessary to the
  content of the page.
• It is possible to hide flash content from both
  web browsers and screen readers.

26

• Other considerations
• To hide these you would add the wmode option
  with the value opaque to both the OBJECT and
  EMBED tags of the web page containing the Flash
  movie
• ltobjectgt
• ltparam namewmode valueopaquegt
• ltembed wmodeopaquegt
• lt/embedgt
• lt/objectgt

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• This would effectively hide the Flash movie from
  the reader and the keyboard, however it will
  still appear on the page.
• Only use this if the movie contains unimportant
  content.

28

• Other References
• Accessibility and Macromedia Flash 2004
• http//www.macromedia.com/macromedia/accessibility
  / features/flash
• Flash Accessibility Whitepaper
• http/www.markme.com/accessibility/files/whitepape
  r.htm
• Bob Regans Flash Accessibility Blog
• http//www.markme.com/accessibility