Java Swing, 2nd Edition

Other Accessible Objects

Before going further, there are several simple objects in the accessibility package used by AccessibleContext that we should discuss in more detail.

The AccessibleState Class

Each accessible component can have one or more states associated with it. An assistive technology can query these states at any time to determine how best to deal with the component. The accessible states can only be retrieved, however, and not set. There are two classes that the Accessible package uses to handle states: AccessibleState and AccessibleStateSet.

The AccessibleState class contains an enumeration of static objects that define states that any accessible component can have. Note that a component can be in more than one state at any time. A list of the possible states that an accessible object can be in, along with a brief description of each, is shown in Table 25-3.

Table 25-3. AccessibleState constants

State	Meaning
ACTIVE	The window, dialog, or frame is the active one.
ARMED	The object, such as a button, has been pressed but not released, and the mouse cursor is still over the button.
BUSY	The object is busy processing and should not be interrupted.
CHECKED	The object is checked.
COLLAPSED	The object, such as a node in a tree, is collapsed.
EDITABLE	The object supports any form of editing.
ENABLED	The object is enabled.
EXPANDABLE	The object, such as a node in a tree, can report its children.
EXPANDED	The object, such as a node in a tree, is expanded.
FOCUSABLE	The object can accept the focus. ...