What Is Accessibility?

When you interact with a computer, you normally input commands by way of a keyboard and mouse, and examine the computer's output by way of a video screen and printer. Unfortunately, many people cannot access a computer by using the conventional keyboard, mouse, video screen, and printer. For example, if a person has no limbs , this person won't be using the keyboard or mouse. Furthermore, a blind person would not have much use for a screen or printer. These people need more accessible computing devices.

You don't have to be physically challenged to benefit from computing devices that are more accessible. For example, suppose you are driving down a busy freeway and you feel a need to adjust your vehicle's environment. Without taking your eyes off the road, wouldn't it be great if you could ask your Java-enabled vehicle to take care of these tasks on your behalf ?

When you interact with a computer, you're really interacting with its software. To become more accessible, this software must be written to take into account assistive technologies. Assistive hardware and software technologies ”such as screen magnifiers, Braille input devices, speech synthesizers, speech recognizers, and so on ”are used either in place of or in conjunction with video displays, printers, mice, and keyboards.

To support assistive technologies, Sun Microsystems has created an accessibility framework designed around the javax.accessibility package. Classes and interfaces contained in this package are used throughout Swing's components to automate much of this support.

Sun has introduced some AWT accessibility support in version 1.3 of the Java 2 Platform Standard Edition. This has been accomplished by making API changes to the AWT's Component and Container classes, along with Component / Container subclasses. However, in the case of certain AWT classes (such as Menu and List ), this support is limited. (Sun is working to extend this support.) For more information, check out the accessibility framework enhancements in the Java 2 Platform Standard Edition version 1.3 documentation.

Because the accessibility framework is designed to be queried by assistive technologies, you will almost never need to interact with its classes and interfaces. However, if you are designing new Swing components, you should support appropriate accessibility interfaces and classes to ensure that assistive technologies can access information about these components.