Accessible Multimedia

Jason Morningstar

UNC Chapel Hill | ITS Communications | Web Services

Goals

• Raise awareness of limitations
• Discuss accessibility features in Flash
• Address specific common issues
• Share some code snippets
• Captioning and Transcription resources

Barriers to Accessibility

• The power of Flash is in its timeline-based flexibility.

• The scripting features of Flash allow dynamic objects to modify themselves.

• Screen readers are designed for static content. Built for a contextual, data-driven medium, applications like JAWS struggle with Flash.

• Despite the limitations, when designed thoughtfully and used appropriately, Flash can be made accessible.

Equivalent Content

• Equivalent does not mean text-only.

• A text-only page is much less ‘equivalent' when compared to a Flash movie than a well formatted and accessible Web page with images, icons, paragraphs, and color.

Text and Audio

• Flash is getting better. Honest!

• With Flash MX 2004, you now have a limited ability to add text equivalents to graphics.

• If your Flash movie contains any audio, it may interfere with the screen reader. Unless the purpose of the Flash movie is to present audio, you should always provide an option to turn the audio off.

   

The Accessibility Panel

• Make Object Accessible - This option can be deselected to make the object invisible to the screen reader. If deselected, the text equivalent and any text immediately within the symbol will not be accessible to the screen reader. This can be useful if the symbol does not convey important content.

• Make Child Objects Accessible - If you have other objects within this clip symbol, you can make them hidden by selecting this option. This is useful for animations that are comprised of multiple parts, but as a whole only need one text equivalent.

   

Accessibility Panel, continued

• Name - The Flash ALT. This is for a brief description of the object.
• Description - The Flash LONGDESC. The screen reader will read the Name first, then the Description if both are present.
• Shortcut – A shortcut key for a specific object does not program the keyboard shortcut, but simply alerts the user as to what the shortcut key is. You will need to program additional ActionScript within the movie to capture that keyboard sequence.

Buttons

• Buttons must have equivalent text added in the Accessibility panel or they must contain text for them to be reliably accessible.

• Often, buttons are set to display content during the 'Over' or 'Down' states, meaning when the mouse is hovering over the button or pressing down on the button. The Flash player will only send a single text item to the screen reader from the Over or Down states of a button. Any additional text items, graphics, or movie clips will be ignored.

Buttons, continued

• Complex button objects, such as sliders, scroll bars, combo boxes, and list boxes are not accessible via the keyboard.

• Drag and drop items or any item that requires a click and drag is not accessible using a keyboard alone.

• Any button that contains an animation cannot be made accessible. If it is not set to inaccessible in the Accessibility panel, it will cause the screen reader to begin reading from the top of the Web page continually. Grr!

Keyboard Focus

• With the exception of version 7 for IE, 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.

Keyboard Focus, continued

• Screen readers have built in functionality which will change focus back to the Web page after all of the Flash items have been accessed. Common browsers, however, do not have this functionality. This can be an issue for people with motor disabilities that must use the keyboard for navigation.
• You can alleviate this by either making the movie invisible to the Web browser or by setting all of your buttons to be inaccessible in the Accessibility panel. But both of these options make the movie itself inaccessible.

Hiding Flash

To hide Flash content from both Web browser and screen readers, add the WMODE option to both the OBJECT and EMBED tags of your the Web page containing the Flash movie. Here’s the relevant code:

< OBJECT ... >
< PARAM NAME="wmode" VALUE="opaque" >
< EMBED wmode=opaque ... >
< /EMBED >
< /OBJECT >

Only use this in the movie does not convey important content or if an alternative is provided for the content the movie does contain.

Reading Order

With ActionScript, you can specify a specific tab order for form, button, and movie clip elements inside your Flash movie. If you want to specify the tab order of text within your movie, you must convert the text to a dynamic text object. To specify a tab order, each object that will be in the tab order must be given a unique instance name. This is added by selecting the item on the stage and typing the name into the Instance Name box on the Properties panel. Now add tabIndex information to a keyframe at frame 1 of your movie:

_root.Homepage.tabIndex = 1
_root.Contact.tabIndex = 2
_root.FirstName.tabIndex = 3
_root.LastName.tabIndex = 4
_root.SubmitButton.tabIndex = 5

Reading Order, continued

• In order for this to work, you must specify a tab order for every button, movie clip, input text, and dynamic text object on the stage that has been set to be accessible in the Accessibility panel. If you miss even one, then screen readers will disregard your tabIndex altogether.

Captioning Software

• Hi Caption
• MAGPie

Captioning Providers

• Caption Colorado
• National Captioning Institute

Transcript Providers

• Local services: Contact Jim Kessler in the Department of Disability Services (962-8300)
• Autosync
• Type-Thing
• We Type 4 U

CART

• Computer Access Realtime Transcription

Handy Links

• Contact me at jason_morningstar@unc.edu
• UNC's Webaccess Flash, Audio, and Video pages
• Bob Regan's Flash Accessibility White Paper (PDF)
• Comprehensive Flash tutorial from the University of Florida

• National Center for Accessible Media