Techniques for WCAG 2.0

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Flash Technology Notes

Adobe Flash Player is a cross-platform browser plug-in. Authors creating content for display by the Flash Player may choose to do so for a variety of factors, including video support, authoring preference, vector-based graphics capabilities, or to take advantage of available components. The motivation of the author notwithstanding, it is equally important to ensure that content playing in the Flash Player meets the accessibility criteria in WCAG 2.0 as it is for other web content.

User Agent Support for Flash

The Flash Player provides a combination of built-in support for accessibility and capabilities that authors and authoring tools can take advantage of in order to enable support for accessible content. Flash authors may use any of a few tools for authoring accessible Flash content, including but not limited to:

For blind, low-vision, and other assistive technology users the Flash Player introduced support for an accessibility API in 2001 with Flash Player 6. Flash accessibility support for assistive technology relies on the Microsoft Active Accessibility (MSAA) interface and a Flash Player-specific interface to properly convey information about Flash content for assistive technologies. Support for assistive technologies is provided for users viewing content using combinations of:

Assistive technology support for MSAA is provided in several assistive technologies, including but not limited to:

Flash Accessibility Support

Flash Player also supports keyboard access for users who are unable to use a mouse. Keyboard support is best within the ActiveX version of the player used in Internet Explorer, but techniques to provide support within Mozilla Firefox are also available. Flash authors can control the tab order of content within published Flash content, as is demonstrated in the WCAG 2.0 techniques for Flash.

Flash Player is often used to display video, and it provides support for text tracks which can be used to provide closed captions or subtitles in any language, and it also supports multiple tracks of audio, thereby enabling support for video description, and it supports multiple video tracks, enabling the delivery of sign language interpretation for audio-visual content.

The Flash Player does not currently support high-contrast mode or text resizing via the Windows operating system. However, Flash authors may take advantage of Flash's support for Cascading Stylesheets (CSS), other built-in style support, or Flash's display filter features to offer alternative views of a Flash-based interface with larger text, alternative fonts, or alternative or high-contrast color schemes.

Flash accessibility support for assistive technology relies on use in Windows operating systems, using Internet Explorer 6 or later (with Flash Player 6 or later) or Mozilla Firefox 3 or later (with Flash Player 9 or later).

For additional general information about the Flash Player, visit the Flash Player FAQ.

Special Considerations for WCAG 2.0 Compliance