Controlling Descriptions And Repetition; Using Color - MACROMEDIA FLASH MX 2004-USING ACTIONSCRIPT IN FLASH Use Manual

Controlling descriptions and repetition

Designers and developers can assign descriptions for the animations, images, and graphics in a
SWF file. Provide names for graphics so the screen reader can interpret them. If a graphic or
animation does not communicate vital information to the SWF file (perhaps it is decorative or
repetitive), or you outlined the element in the overall SWF file description, do not provide a
separate description for that element. Providing unnecessary descriptions can be confusing to
users who use screen readers. For more information on assigning names and descriptions, see
"Using Flash to enter accessibility information for screen readers" in Using Flash.
Note: If you divide text or use images for text in your SWF files, provide either a name or description
for these elements.
If you have several nested movie clips that serve a single purpose or convey one idea, ensure that
you do the following:
•
Group these elements in your SWF file.
•
Provide a description for the parent movie clip.
•
Make all the child movie clips inaccessible.
This is extremely important, or the screen reader tries to describe all the irrelevant nested movie
clips, which will confuse the user, and might cause the user to leave your website. Make this
decision whenever you have more than one object, such as many movie clips, in a SWF file. If the
overall message is best conveyed using a single description, provide a description on one of the
objects, and make all the other objects inaccessible to the screen reader.
Looping SWF files and applications cause screen readers to constantly refresh. This occurs
because the screen reader is detecting that there is new content on the page, and because it thinks
the content is updated, it returns to the top of the web page and starts rereading the content. You
should make any looping or refreshing objects that do not have to be reread inaccessible to screen
readers.
Note: Do not type a description in the Description field of the Accessibility panel for instances (such
as text) that the screen reader reads aloud.

Using color

It is tempting to use a wide array of colors in a Flash SWF file. It is possible to use all these colors
in an accessible SWF file, but you must make some decisions about it. For example, you must not
only rely on color to communicate particular information or directives to users. A color-blind
user cannot operate a page if it asks to click on the blue area to launch a new page or the red area
to hear music. Offer text equivalents on the page or in an alternate version to make your site
accessible. Also, check that there is significant contrast between foreground and background
colors to assist users who have difficulty seeing particular colors, to enhance readability. If you
place light gray text on a white background, users cannot easily read it. Similarly, small text,
which is commonly found in many Flash websites, is difficult for many visitors to read. Using
high-contrast and large or resizable text benefits most users, even those without impairments.
132 Chapter 3: Using Best Practices