Ensure Keyboard Access
It is important that all controls that can be manipulated via the mouse also be accessible via the keyboard. This is intended to support users with mobility impairments as well as screen reader users.
The Adobe Flash Player facilitates keyboard access on its own by automatically making mouse defined events accessible via the keyboard. However, there are two specific techniques commonly used among Adobe Flash designers that should be avoided. In addition, designers should add keyboard shortcuts to facilitate keyboard access in complex applications. Finally, designers should be aware of an issue with the Flash Player 9 and earlier in pages that blend HTML and Flash content.
on (click) {
getURL(index.html);
}
For example, the ActionScript 2.0 script shown above might be used to open a web page. It is directly associated with the instance of the movie clip used as a button. This script should instead be placed in a frame, likely the first frame, of the movie. The revised script, converted to ActionScript 3.0 could be as follows:
Please note that the following script uses the ActionScript MouseEvent, but this method is also operational from the keyboard.
function gotoAdobeSite(event:MouseEvent):void
{
var adobeURL:URLRequest = new URLRequest("http://www.adobe.com/");
navigateToURL(adobeURL);
}
home_mc.addEventListener(MouseEvent.CLICK, gotoAdobeSite);
Flash allows a higher level of keyboard interaction than is allowed in HTML. Many Flash movies can be made more functional, powerful, and easy to use by allowing keyboard access. View a keyboard example.
Warning: Avoid Empty Hit Areas
Hit areas are empty button clips with a shape defined in the hit state. These allow designers to reuse a single library objects repeatedly by placing them over text objects and varying only the scripts used. The problem with this technique is that screen readers assume that if the contents of the up state of a button clip is empty, then it is not a button at all.
Solution: Simple - make the hit state a movie clip in the up state, extend it over all the button frames and set the alpha to 0%! The screen readers will recognize the button and allow the user to activate it.
Assign Keyboard Shortcuts for Most Essential Controls
For users with mobility impairments, pressing keys may be very difficult. Therefore in complex applications with multiple controls, it is extremely helpful for users to navigate the application using keyboard shortcuts. By using keyboard shortcuts helps to reduce the number of keystrokes required to perform important tasks.
Using the shortcut field on the Accessibility panel or the .shortcut property in ActionScript is not enough. Creating a keyboard shortcut requires that a listener event be defined and a script associated with that listener. Please note the shortcut field does not create the listener.
The controls page has a great example and tutorial using keypress shortcuts. Check it out!!
