Java Accessibility Documentation: Explorer Example

JAVA ACCESSIBILITY

Explorer Example

Version 1.0

March 1998

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Based on user settings (in the Settings menu), Explorer tracks mouse movement, focus updates, and text caret movement in a particular Java^TM Virtual Machine. If set to do so, when it detects that the mouse has stopped moving for a short period of time, it calls EventQueueMonitor's method, getAccessibleAt, to determine the Accessible object under the mouse. Once it has done so, it displays the Accessible information of that object. Similarly, if set to do so, when it detects that a new UI object has the focus, it displays the Accessible information for that new UI object. Further, if set to do so, it will display the Accessible information for the text object containing the caret when the caret moves. Finally, if set to do so, it will call EventQueueMonitor's method, getAccessibleAt, to determine the Accessible object under the mouse when the user the F1 key, and then display the Accessible information of that object.

To run Explorer you need to have obtained and installed the JDK1.1.5 or better, and the Java Foundation Classes .

Snap shot of Explorer in action.

Preparing to Run Explorer:

The Explorer class is in the examples/Explorer directory included with this release of the Java Accessibility Utilities (click here to view the source). Before you can run it, you need to set up your environment appropriately by following these instructions:

Modify your CLASSPATH environment variable so that the jaccess.jar file that comes with this kit is included in the path.

Modify your CLASSPATH environment variable so that the examples/Explorer and examples/AccessibilityPanels directories that come with this kit are included in the path.

Modify your $JDKHOME/lib/awt.properties file to include the following lines (a sample awt.properties can be found here):
AWT.EventQueueClass=com.sun.java.accessibility.util.EventQueueMonitor
AWT.assistive_technologies=Explorer

After you follow these instructions, you should be ready to run Explorer. If you did not set up your CLASSPATH correctly you might get one of the following errors when running a Java application:

Failed loading com.sun.java.accessibility.util.EventQueueMonitor: java.lang.ClassNotFoundException: com.sun.java.accessibility.util.EventQueueMonitor

Error trying to newInstance Explorer java.lang.ClassNotFoundException: Explorer

The first error means that the jaccess.jar file is not in your CLASSPATH, and the second that the Explorer directory is not in your CLASSPATH.

Running Explorer:

By following the instructions above, Explorer will automatically be started any time you start a Java application. For example, if you run the "SwingSet" demonstration application that comes with the Java Foundation Classes, Explorer will automatically start.

Using Explorer:

Choose the mechanism(s) you want to use Explorer by making selections from the Settings menu. Until you tell Explorer how to explore, it will remain quiescent. To automatically explore the Java Accessibility API of the object under the mouse as the mouse moves, choose "Track Mouse" from the Settings menu. To automatically explore the Java Accessibility API of the object receiving focus, choose "Track Focus" from the Settings menu. To automatically explore the Java Accessibility API of the text object in which caret movements are occuring, choose "TrackCaret". Finally, to explore the Java Accessibility API of objects under the mouse upon command when you hit the F1 key on your keyboard, choose "Update with F1 key" from the Settings menu.

To submit comments or suggestions about Java Accessibility, please send mail to access@sun.com.