Accessibility Properties

Available Properties

The javax.accessibility package provides the following properties:

• assistive_technologies
• screen_magnifier_present
• screen_reader_present

Loading Assistive Technologies

The assistive_technologies property specifies the assistive technologies to load into the JVM. It takes a comma-delimited list as input.

Indicating the Presence of a Screen Magnifier

When the screen_magnifier_present property is set to true, it lets the Java platform libraries know that a screen magnifier is present on the system. Application developers can check this property, and if a screen magnifier is present, developers should make sure their applications are compatible with screen magnification. For example, on Microsoft Windows operating systems, the reference implementation of the Java 2D^TM API checks this property and if true, turns off Microsoft DirectDraw to avoid problems with the screen magnifier. (Some screen magnifiers may not be able to magnify DirectDraw graphics.)

Indicating the Presence of a Screen Reader

When the screen_reader_present property is set to true, it lets the Java platform libraries know that a screen reader is present on the system. Application developers can check this property. If an application is self-voicing and a screen reader is present, developers can turn off the self-voicing.

Setting Properties

You can set a property at run time or in a properties file. To set a property at run time, enter a command such as the following:

java -Djavax.accessibility.screen_magnifier_present=true foo.class

The reference implementation includes an accessibility.properties file in the jre/lib directory. To set a property in the accessibility.properties file, add a line or lines such as the following:

assistive_technologies=Ferret,Monkey
screen_magnifier_present=true
screen_reader_present=true