Adobe Flash Professional CC 2014 v.13.0 - Manual (Page 849)

Best practices - Accessibility guidelines
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About accessibility guidelines
Creating accessible sites
Exposing SWF file structure and navigation
Controlling descriptions and repetition
Using color
Ordering, tabbing, and the keyboard
Handling audio, video, and animation
Accessibility and extending Flash
Testing files and making changes
About accessibility guidelines
Screen readers are complex, and you can easily encounter unexpected results in FLA files developed for use with screen readers, which is
software that visually impaired users run to read websites aloud. Text is read aloud using specially designed software. A screen reader can only
interpret textual content. However, any descriptions that you provide for the overall SWF file, movie clips, images, or other graphical content are
also read aloud. Write descriptions for the important images and animations so that the screen reader can also interpret these assets in your SWF
file. This is the SWF file equivalent to alt text in an HTML web page.
Note: Flash Professional applications must be viewed in Internet Explorer on Windows, because Microsoft Active Accessibility (MSAA) support is
limited to this browser.
Flash Player uses Microsoft Active Accessibility (MSAA) to expose Flash Professional content to screen readers. MSAA is a Windows-based
technology that provides a standardized platform for information exchange between assistive technologies, such as screen readers, and other
applications. Events (such as a change in the application) and objects are visible to screen readers by using MSAA.
Note: Flash Player 7 (and later) does not work with all screen-reader technologies. The third-party software provider must handle the information
that MSAA provides.
Creating accessible sites
Making a website accessible involves several different criteria:
Expose the information to screen readers Make text or images realizable Some visitors might have difficulty reading small text or seeing small
graphics. Allow users to zoom in on these elements, taking advantage of scalable vector graphics in SWF files.
Provide audio narration Consider providing an audio narration for visitors without a screen reader, or where screen readers might not work, such
as with video content.
Provide captions for audio narrations Some visitors might not be able to hear an audio narration for your site or a video. Consider providing
captions for these visitors.
Do not rely on color to communicate information Many visitors might be color blind. If you rely on color to communicate information (such as:
Click the green button to go to page 1, click the red button to go to page 2), provide text or speech equivalents.
Historically, many online presentations (such as videos) provide alternative ways for visually impaired visitors to access the content, for instance, a
textual description of a video. However, Flash Professional provides textual information directly to the screen reader. Although this usually means
you need to make additional settings or ActionScript in a FLA file, you do not have to create a completely separate version.
Parts of your SWF file can be exposed to screen readers. Text elements (such as text fields, static text, and dynamic text), buttons, movie clips,
components, and the entire SWF file can be interpreted by MSA-compliant screen readers.
Section 508 is United States legislation that provides guidelines for making information accessible to people with disabilities. Section 508
specifically addresses the need for websites to be accessible in several ways. Some websites, including all federal websites, must comply with
these guidelines. If a SWF file does not communicate all of the information to the screen reader, the SWF file is no longer Section 508-compliant.
For more information, see the Section 508 website.
Many nations have specified guidelines to follow to create accessible web sites, or follow guidelines established by other organizations. For more
information on accessibility and web standards, see the World Wide Web Consortium (W3C) Web Accessibility Initiative website. These standards
and guidelines describe what factors you must address when you create accessible HTML websites, and some of this information applies to Flash
Professional.
Exposing SWF file structure and navigation
Because of the visual nature of some SWF files, the layout and navigation of the page can be complex and difficult for screen readers to translate.
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