User Agent Support Notes for Flash Techniques

This page documents user agent support notes for Flash Techniques.


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

FLASH1: Setting the name property for a non-text object

See User Agent Support for Flash for general information on user agent support.

FLASH2: Setting the description property for a non-text object in Flash

FLASH3: Marking objects in Flash so that they can be ignored by AT

FLASH4: Providing submit buttons in Flash

FLASH5: Combining adjacent image and text buttons for the same resource

FLASH6: Creating accessible hotspots using invisible buttons

FLASH7: Using scripting to change control labels

FLASH8: Adding a group name to the accessible name of a form control

FLASH9: Applying captions to prerecorded synchronized media

FLASH10: Indicating required form controls in Flash

FLASH11: Providing a longer text description of an object

FLASH12: Providing client-side validation and adding error text via the accessible description

FLASH13: Using HTML language attributes to specify language in Flash content

JAWS 8.0 or later can be configured to change language automatically on the basis of the lang attribute. However, it only switches amongst major languages as indicated by the primary code. If a regional language variant is indicated with a language subcode, JAWS will use the default variant for which it is configured.

FLASH14: Using redundant keyboard and mouse event handlers in Flash

FLASH15: Using the tabIndex property to specify a logical reading order and a logical tab order in Flash

FLASH16: Making actions keyboard accessible by using the click event on standard components

FLASH17: Providing keyboard access to a Flash object and avoiding a keyboard trap

The problem targeted by this technique only occurs in browsers other than Internet Explorer. Currently however, this technique works in Firefox on Windows and OSX, and for Google Chrome and Safari 5 on OSX. The Windows versions of Chrome and Safari do not currently shift focus to and from plug-ins correctly. Additionally, JavaScript needs to be enabled for this technique to work.

FLASH18: Providing a control to turn off sounds that play automatically in Flash

FLASH19: Providing a script that warns the user a time limit is about to expire and provides a way to extend it

FLASH20: Reskinning Flash components to provide highly visible focus indication

FLASH21: Using the DataGrid component to associate column headers with cells

FLASH22: Adding keyboard-accessible actions to static elements

FLASH23: Adding summary information to a DataGrid

FLASH24: Allowing the user to extend the default time limit

FLASH25: Labeling a form control by setting its accessible name

FLASH26: Applying audio descriptions to Flash video

FLASH27: Providing button labels that describe the purpose of a button

FLASH28: Providing text alternatives for ASCII art, emoticons, and leetspeak in Flash

FLASH29: Setting the label property for form components

FLASH30: Specifying accessible names for image buttons

FLASH31: Specifying caption text for a DataGrid

FLASH32: Using auto labeling to associate text labels with form controls

FLASH33: Using relative values for Flash object dimensions

FLASH34: Turning off sounds that play automatically when an assistive technology is detected

FLASH35: Using script to scroll Flash content, and providing a mechanism to pause it

FLASH36: Using scripts to control blinking and stop it in five seconds or less