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Java Accessibility FAQ
Getting started with Java Accessibility
Usage
Certification
Performance
Compatibility & Development
Release & Delivery Info.
Use with Assistive Technologies
Question Index
What does 'Accessible' mean in this
context?
There are over 40 million Americans with disabilities, and far more
worldwide. For many of these individuals, their disability makes
it difficult to impossible to use computers and computer software as they
are shipped from the manufacturer. These individuals need some form
of computer accommodation which provides them with access to the same applications
that everyone else can use use unaided. These accommodations include:
screen readers which use synthesized speech to read the contents of a screen
to a person who is blind; screen magnifiers which enlarge a portion or
all of the screen sometimes as much as 16 times for a person with some
sight but who would otherwise be unable to see the screen; on-screen keyboards
with word prediction and speech recognition systems for people with physical
impairments who cannot type on a standard keyboard. In order to ensure
that these accommodations function properly on a computing platform, that
platform needs to make the system and the software that runs on it accessible,
either directly (e.g. a talking Web browser), or by ensuring that it works
with assistive technologies on that platform (e.g. is compatible with screen
readers). In the United states, there are a number of relevant laws
designed to ensure that individuals with disabilities have full and equal
access to computer technology in education and the workplace (see: http://java.sun.com/javase/technologies/accessibility/index.jsp).
Question Index
Who do I contact for more information?
Question Index
How much does Java Accessibility cost?
Nothing -- it is absolutely free.
Question Index
What is Sun doing to make the Java Platform
Accessible?
Sun is broadly doing 4 things with Accessibility on the Java Platform:
1. We have developed an API (the Java Accessibility API) to allow Java
applications to be compatible with screen access software. This API
is available the Java package 'javax.accessibility', shipping as part of
the Java Foundation Classes version 1.1, downloadable at http://java.sun.com/products/jfc
and also shipping as part of the Java Platform implementation Java 2 Standard Edition,
downloadable at http://java.sun.com/products/jdk/1.2.
2. We have developed a set of utilities for Assistive Technology vendors
(the Java Accessibility Utilities package), that allows them to easily
make queries of the system (things like "GetObjectAtPoint",
"GetTopLevelWindows", etc.), which is available as a downloadable package to
work in any Java VM from JDK 1.1 to the present.
3. We are developing a standard
mechanism for getting the Java Accessibility API information out of the
Java VM and to assistive technology running in the native host environment
(the Java Accessibility Bridge). This mechanism will be based on
JNI - Java Native Interfaces.
4. We developed the pluggable look & feel architecture to support
direct accessibility in the Java Foundation Classes (downloadable at http://java.sun.com/products/jfc).
With the pluggable look and feel architecture, mainstream developers can
build Java applications whose user interface is chosen by the user (who
might choose an audio interface instead of, or in addition to, a visual
interface).
Question Index
What about Microsoft's 'Active Accessibility for Java'?
Microsoft has an accessibility interface for the Win32 platform called
'Active Accessibility' which provides access to Microsoft Windows-specific
information about applications running on that platform. Microsoft
announced an API for extending Active Accessibility to Java applications
built using AFC when running in Microsoft Internet Explorer on a Win32
OS. This API contains a number of things that are only available
in Microsoft Windows (e.g. pointers to Microsoft Windows help file entries).
Question Index
Was Microsoft invited to take part in the
design of Java Accessibility?
Yes. As an important licensee, Microsoft was invited to collaborate
on the design of Java Accessibility from the beginning, and took part in
the Accessibility review of JDK 1.0.2 (report at: http://www.trace.wisc.edu/docs/java_access_rpt/report.htm,
contributed to by the Microsoft Accessibility team), and at every design
meeting for Java Accessibility that comprised more than just Sun employees.
Question Index
What is in the Java Accessibility API?
The Java
Accessibility API defines the contract between mainstream Java applets/applications
and Assistive Technologies through the Accessible interface.
This interface contains a method to get the AccessibleContext
class, which contains the core common set of Accessibility information
that every user-interface object must provide. In addition, the Java
Accessibility API defines a set of additional interfaces for providing
access to specific types of user-interface objects.
interface AccessibleAction:
For all user-interface objects. This interface provides the standard
mechanism for retrieving all of the accessibility information about an
object (by returning an instance of the AccessibleContext class
for the object). All user-interface objects should implement interface
Accessible and return the appropriate AccessibleContext
when asked.
class AccessibleContext:
For all user-interface objects. This class provides methods for
retireving the name and description of the object, the object's role and
states, the objects parent and children, the objects locale, and property
change listening a mechanism for tracking changes to this information.
All user-interface objects should implement interface Accessible
and return the appropriate AccessibleContext when asked.
interface AccessibleAction:
For objects that can perform one or more actions. This interface
provides the standard mechanism for an assistive technology to determine
what those actions are and tell the object to perform those actions. Any
object that can be manipulated should provide this interface.
interface AccessibleComponent:
For objects that have a graphical representation. This interface
provides the standard mechanism for an assistive technology to determine
and set the attributes of the graphical representation of the object.
Any object that is being rendered onto the screen should provide this interface.
interface AccessibleSelection:
For objects that allow their Accessible children to be selected.
This interface provides the standard mechanism for an assistive technology
to determine what the current selection is as well as manipulate that selection.
Any object that contains children we can be selected should provide this
interface.
interface AccessibleText:
For objects that present editable textual information on the display.
This interface provides the standard mechanism for an assistive technology
to access that text via its content as well as providing spatial location.
Any object that contains editable text should provide this interface.
interface AccessibleHypertext:
For objects that present hyper textual information on the display.
This interface extends the AccessibleText interface, and provides additional
mechanism for an assistive technology to enumerate and activate the hyperlinks
with that text. Any object that contains hypertext should provide
this interface.
interface AccessibleValue:
For objects that contain a varying numerical value. This interface
provides the standard mechanism for an assistive technology to determine
and set the current value of the object, as well as the objects minimum
and maximum values. Any object that contains a varying numerical
value should provide this interface.
The Java Accessibility API is extensible, and additional specialized
interfaces are planned for future version, including interface AccessibleTable,
and interface AccessibleDocument.
Question Index
What is in the Java Accessibility
Utilities package?
The Java Accessibility Utilities package contains two major pieces:
1. a set of utility classes (the com.sun.java.accessibility.util class
package) for use by Assistive Technology Vendors which provides methods
for listening to all AWT and JFC events in any running Java applications;
for getting the object at any given point in any Java window on the screen;
for enumerating the top-level Java windows that are open; for getting the
current Java component that has the keyboard focus; and for retrieving
the current mouse cursor location
2. example Java applications with full source code illustrating various
techniques for providing access to Java applications via the Java Accessibility
API
Question Index
How will Java Accessibility be used...
...by developers?
Developers who want to write directly-accessible Java applications
use the Java Foundation Classes and the pluggable look and feel architecture
to design applications that are independent of the actual modality of the
interface. In this way, a user can choose to use an interface of
that users' choice (e.g. a low-vision interface, or an audio interface,
etc.).
Developers who want to ensure that their Java applications will interoperate
with assistive technologies, such as screen readers, Braille terminals,
etc., use the Java Accessibility API in all of the user-interface components
of their applications. If they are exclusively using the user-interface
components of Java Foundation Classes to build their applications, most
of their work to ensure compatibility is done; they need to simply ensure
that appropriate names and descriptions are set on each of the user-interface
components. If these developers are using user-interface components
from other class libraries, or if they are developing their own custom
user-interface components, they need to explicitly support the Java Accessibility
API.
...by Assistive Technology vendors?
Vendors are building alternate user interfaces for the Java Foundation
Classes to provide interfaces in non-traditional modalities, including
the current development of low-vision and audio user interfaces for the
JFC.
Vendors are also building Assistive Technologies in Java, such as the
IBM Special Needs Systems group,
which is building a screen reader for the Java platform that will provide
blind access to Java applications which support the Java Accessibility
API.
Finally, vendors of native Assistive Technologies (such as those found
on the Macintosh, Microsoft Windows, and OS/2 platforms), will be utilizing
the forthcoming Java Accessibility Bridge to provide access to Java applications
running within those operating system environments.
Question Index
Who is using Java Accessibility?
The many developers who are building products on top of the Java Foundation
Classes are already automatically transparently using Java Accessibility
to make their applications accessible. Assistive Technology vendors
are currently building products on top of Java Accessibility, including
the IBM Special Needs Services group, which has announced the development
of a screen reader for the Java platform.
Question Index
Is Java Accessibility easy to use?
Since it is built into the Java Foundation Classes, which is core to
the Java Platform and thus don't need to be ported from a different environment,
developers will find that the Java Accessibility is very easy to use -
virtually all of the work is done for them. Furthermore, the accessibility
information provided by the Accessibility Interfaces can be found in virtually
any set of Java User Interface classes, so developers who want to make
their own class libraries accessible via the Java Accessibility standard
can do so easily, thereby ensuring that their class libraries and applications
built using them can be accessible.
Question Index
Are there guidelines for using the Java
Accessibility API correctly?
The IBM Special Needs Systems
group has been a close partner in the development of the Java Accessibility
API, and they have developed a set of Guidelines
for Writing Accessible Applications in the Java programming language.
This document describes in detail how to use the Java Accessibility API
and the Java Foundation Classes in order to develop mainstream applications
that are fully accessible.
Question Index
Is there an "Accessible" certification process?
Not at this time. To 100% certify that a Java application is
accessible, one would have to certify that it is accessible by every possible
alternative means of using a computer (e.g. screen reader, keyboard alternative,
etc.), on a per-Assistive Technology basis. However, Sun is investigating
ways to certify that an application fully implements the Java Accessibility
interfaces, which will go a long way toward ensuring that it will work
properly with Assistive Technologies.
Question Index
How does Java Accessibility relate to the 100%
Pure Java program?
The Java Accessibility API, which is implemented in the Java Foundation
Classes, provides the building blocks that enable developers to easily
create a accessible applications that are 100% Pure Java.
Question Index
Does Java Accessibility run better
on certain platforms?
No. Since Java Accessibility is designed to be truly cross-platform,
developers can take advantage of its ease of use on all Java Compatible
Platforms.
The Java Accessibility Bridge,
which provides a mechanism for existing native Assistive Technologies to
communicate with programs on the Java platform using the Java Accessibility
API, requires platform-specific code and when released may function differently
on different platforms.
Question Index
Will developers have to worry about the size
of Java Accessibility?
No. The code itself is very small, even though it is quite comprehensive.
Furthermore, because Java Accessibility is core to the Java Platform, it
will already be every machine that supports the Java Foundation Classes
as well as the next version of the JDK.
Question Index
How does Java Accessibility affect Sun's AWT?
The Java Accessibility Utilities package includes a lot of accessibility
support for AWT, providing mechanisms for externally monitoring all AWT events,
and for externally retrieving the AWT object at any given point on the
screen. AWT is not made fully accessible with this release of Java
Accessibility, as that requires changes to AWT, which will not be part
of the Java 2 Standard Edition release in 1998.
Question Index
How do the Java Foundation Classes support
Accessibility?
In addition to including the Java Accessibility API, the Java Foundation
Classes are build using the Pluggable Look & Feel architecture.
The Pluggable L&F separates the Look & Feel of a Java application
from the underlying model and logic behind that application. While
this make it easy to have custom looks for an applications (such as a "Macintosh"
look and a "Windows" look), it more importantly means that standard applications
built using the JFC can have instead an "audio" look, a "Braille" look,
and so forth. With the JFC, for the first time in the history of
the Assistive Technology industry, applications built using the JFC can
be directly accessible via speech or Braille simply by having the user
choose an audio or Braille UI factory for that application. This
direct accessibility support means that alternative interfaces such as
audio and Braille are first-class citizens, alongside their visual counterparts,
rather than only being supported through interpretive layers such as screen
readers and screen magnifiers.
Question Index
How was Java Accessibility designed?
The Java Accessibility API was created through an open design process
based on input from experts in the assistive technology field, including
developers who have implemented screen readers on four different platforms,
the alternative keyboard interfaces standard that is part of X Windows,
accessibility professors from Stanford and the University of Wisconsin-Madison,
and engineers from Sun, IBM, Apple, and Microsoft. In addition, the
IBM Special Needs Services group contributed source code to the implementation
of the Java Accessibility API on a number of the user-interface components
in the Java Foundation Classes, as well as proof-of-concept testing via
the development of their screen reader.
The Pluggable Look and Feel architecture of the Java Foundation Classes
was developed based on the input of many experts in user-interface design,
and tested by the over 300,000 developers who have downloaded them during
their development cycle. One of the key design reasons for making
the Pluggable Look and Feel was to support direct accessibility in the
modality of the user's choice. Several Assistive Technology developers
are creating alternate user interfaces using the Pluggable Look and Feel
architecture, and their input helped shape the design during its development.
Question Index
What about Java applications that aren't
built using JFC?
These programs will automatically be somewhat accessible because they
are build on top of AWT, to which the Java Accessibility Utilities provide
some access. However, to be fully accessible, these applications
should directly support the Java Accessibility interfaces, or be built
on top of some other class libraries that support Java Accessibility.
Question Index
Do any class libraries other than those that
come with JFC support Java Accessibility?
None have announced their support at this time, though a number of
class library vendors and Java Bean developers are reviewing the Java Accessibility
API, and several took part in the design of Java Accessibility.
Question Index
Will there be any compatibility issues
for accessible applications created with JDK 1.1 and JFC in future versions
of the JDK?
The JDK is backwards compatible which means that JFC applications created
for JDK 1.1 and JFC will be able to run on Java 2 Standard Edition, to be released later this
year. The only requirement is that developers use JFC 1.1 with Swing 1.1
or better, as the names of both the Java Accessibility API package and the
Swing package have changed.
Question Index
Which version of the Java Accessibility
Utilities should I use with specific versions of the JFC, the JDK, and the
Java Plugin?
Question Index
Where can I download Java Accessibility?
The Java Accessibility API is available for download
as part of the Java Foundation Classes version 1.1, at http://java.sun.com/products/jfc.
The Java Accessibility API is also available for download as part of the
Java Developers Kit (JDK) version 1.2. Java 2 Standard Edition can be found at the
Java 2 Standard Edition site
Information on downloading the
Java Accessibility Utilities package is available at http://www.sun.com/access.
Question Index
When can developers start using Java
Accessibility?
We want developers to start using Java Accessibility, and using the
Java Foundation Classes to write accessible Java applications immediately,
as several licensees and partners already have. JDK 1.1 supports
Java Accessibility and the Java Foundation Classes, which means that ISVs
can not only develop accessible applications as well as Assistive Technologies
for Java, but can deploy them now.
Question Index
Who creates the Java environment that
I am running on my system?
Independent software vendors, operating system vendors, hardware companies,
etc. who have licensed the Java platform (known as "Java Platform licensees",
of which there are over 120 at last count) each create and release for
sale products which can execute programs written in the Java language (known
as "Java Virtual Machines", or simply "Java VMs"). These include
Microsoft, which distributes Java VMs in Internet Explorer, the J++ environment,
and other products; Netscape, which distributes a Java VM in Netscape Navigator
and Netscape Communicator; IBM, which distributes a Java VM in OS/2 and
for a number of their network computers; Apple, which distributes a Java
VM in the Macintosh operating system; Silicon Graphics, which distributes
a Java VM in their IRIX operating system; and Sun Microsystems, which distributes
a Java VM in their Solaris operating system. In addition, Sun Microsystems
makes available free reference implementations of the Java Platform for
Solaris and for several of the Microsoft Windows environments (Windows
95, Windows 98, and Windows NT 3.5, and 4.0).
Question Index
What control does Sun have over the
creation and distribution of Java environments? Of Java applications
and applets?
All Java Platform licensees sign an agreement in which they agree (among
other things) to only distribute a Java Platform which passes the Java
Compatibility test suite. This test suite ensures the "write once,
run anywhere" proposition which means that a Java program developed on
(for example) a Solaris Java VM, will run properly on (for example) a Macintosh
with the Apple Java VM, so long as that Java program uses only those APIs
and language features of the Java Platform as defined by Sun Microsystems.
Sun Microsystems has no control over the creation and distribution of
Java applications and applets. Anyone can write a program using the
Java language. That program can then do anything that a program written
in any other language can do. Specifically, it can use hardware specific
features (e.g. tie itself to an operating system like Windows). It
can also create a user-interface that is incompatible with assistive technologies
like screen readers.
Question Index
Are there different kinds of Java applications
and applets from the point of view of accessibility?
Yes. There are basically three different kinds of Java applications
and applets from the point of view accessibility. They are:
-
applications whose user-interface is created using only the Abstract
Windowing Toolkit (or AWT); which provides a limited set of user-interface
controls (things like menus and check boxes, etc.; but it doesn't contain
things like tabbed panes and trees and floating palettes and toolbars).
-
applications whose user-interface is created using only user-interface
controls which implement the new Java Accessibility API, which provides
for communication with assistive technologies such as screen readers, screen
magnifiers, etc. The Swing user-interface toolkit which is part of
the Java Foundation Classes is currently the only toolkit which supports
the Java Accessibility API. Swing contains a much richer set of user-interface
controls than it's predecessor, AWT. Specifically, it contains things
like tabbed panes, trees, floating pallettes, and toolbars. In addition,
Swing contains a number of powerful user-interface controls that weren't
available in other platforms, such as hypertext viewers and tables.
-
applications whose user-interface is created using one or more user-interface
controls that don't come from either AWT or which implement the Java Accessibility
API (such as those user-interface controls which were fairly commonly developed
by a number of independent software vendors).
Question Index
What are the differences between these
three kinds of Java applications/applets from the point of view of accessibility?
In some implementations of the Java Platform (notably the reference
implementations from Sun for Windows and Solaris; and the Apple implementation
for Macintosh), the AWT user-interface controls are realized and rendered
both in the Java VM, and on the host (or "native") environment. Specifically
in the Microsoft Windows environment (for example), an AWT button is rendered
as a Windows button; the same is the case with AWT check boxes, menus,
text fields, etc. This has the unintentional (but good!) side effect
of making those AWT user-interface controls (and those Java applications
and applets which restrict themselves to those controls) accessible to
native assistive technologies such as screen readers, so long as they are
running in a Java VM which behaves this way with AWT user-interface controls.
Existing screen access solutions that work with native user-interface controls
should continue to work with Java applications/applets written using only
the AWT components, when those Java programs are run in a Java VM that
exposes AWT components as native components (such as the Sun Microsystems
reference implementation for Windows and for Solaris, and the Apple Computer
implementation for the Macintosh).
Java applications/applets written using only the Swing user-interface
controls render them as "lightweight" controls - they have no native (e.g.
Windows) peer, and so from the native host, they do not appear as actual
user-interface controls (e.g. buttons, check boxes, etc.), but rather simply
as pictures, perhaps with text rendered inside them (e.g. an "OK" button
would appear as the text "OK", with some graphics drawn around it that
to a sighted user will happen to be seen as a button). However, all
Swing user-interface controls support the Java Accessibility API, and so
assistive technologies can provide access to them, even though the native
host doesn't recognize them as valid user-interface controls.
Java applications/applets written using any other set of user-interface
controls will in all likelihood not be peered, and so assistive technologies
will not see them as native controls. Furthermore, unless the Java
application developers specifically supports the Java Accessibility API
in the programs they create using these other user-interface controls,
even those assistive technologies which use the Java Accessibility API
won't be able to provide access to them. In the future, we expect
that other user-interface toolkits will incorporate support for the Java
Accessibility APIs, but currently Swing is the only such user-interface
tookit.
Question Index
What changes with respect to accessibility
in the forthcoming release of Java 2 Standard Edition?
Java 2 Standard Edition contains, among a host of other features, three things important
to accessibility. It contains the Java Accessibility API (which becomes
a defined part of the Java Platform with this release), the Swing user-interface
classes, and the Java2D graphics libraries. This means that in the
future over time as the various Java Platform licensees upgrade to JDK
1.2, their Java VMs will have these features built-in, and developers
will start shipping Java applications and applets which utilize these new
features. Developers can already ship Java applications and applets
which depend upon the first two, as they can be downloaded to a JDK 1.1
environment.
The first two new features of Java 2 Standard Edition have been discussed before.
The Java2D library is a new set of graphics primitives which supersede
the older set contained in AWT. This new set is designed to meet
the needs of graphics professionals. Previous to Java2D, all programs
written in Java could display text in one of only three fonts: Times, Courier,
and Helvetica - and then in only one of four styles: Normal, Bold, Italic,
and Bold-Italic. This is because only those three fonts in those
four styles were guaranteed to be on all systems that the Java platform
ran on. Java2D introduces a new mechanism for rendering text: TrueType
and Postscript fonts are rendered directly by the Java2D subsystem.
This allows a Java program to make full use of not only the fonts installed
on the host system (e.g. all installed Macintosh fonts), but also to dynamically
render in fonts that may be stored on a server, and not installed on the
client system (since it would be wrong for a Java applet to install new
fonts dynamically onto a users system). In addition, since Java2D
has complete control over font rendering, it provides additional functionality
in the rendering of text unavailable before, including anti-aliasing for
greater legibility, a host of type-effects, the ability to rendering text
along a path (e.g. for maps), etc. Also text can be legibly rendered
on top of other images.
In order to provide this rich text support, however, it is necessary
for Java2D to bypass the text rendering subsystem of the host platform.
Specifically, in the Sun Microsystems reference implementation of Java 2 Standard Edition
for Windows, Java2D uses the DirectDraw APIs for rendering text and graphics
directly to the video driver. This technique, just like digital video
rendering techniques by QuickTime and Microsoft AVI players, will bypass
the Off-Screen-Models of Windows screen readers, and may not be compatible
with those Windows magnification tools which don't work with DirectDraw.
Assistive technologies on the Windows platform will need to support the
Java Accessibility API in order to provide access to text rendered using
Java2D.
Note: in Java 2 Standard Edition those UI controls rendered using AWT (e.g. awt.Button,
awt.TextField, etc.) continue to be peered controls and in the Sun Microsystems
implementation for Windows will still be rendered as Windows controls (e.g.
BUTTON, TEXTFIELD), and not rendered by Java2D. Specifically this
means that any AWT-based Java program that worked with screen access solutions
under JDK 1.1 should still work under Java 2 Standard Edition. However, newer Java
programs (such as those which use the new Swing user-interface classes)
will go from "pretty inaccessible" (text visible, but no knowledge of structure,
layout, or semantic meaning) to "completely inaccessible" (the entire window
becomes a picture) in the switch from JDK 1.1 to Java 2 Standard Edition until such time
as screen access solutions incorporate support for the Java Accessibility
APIs.
Question Index
How do native (e.g. Windows and Macintosh)
screen readers provide access to Java applications and applets running
on my system?
Screen readers generally provide access to applications by presenting
in speech and/or Braille the various elements that make up the user-interface
of those applications. In Java, this is done in one of two ways:
-
The first way is by providing access to the native/host user-interface
elements in those cases where the Java application or applet uses the AWT
user-interface elements and the Java VM in which the Java application or
applet is running realizes AWT user-interface elements as native/host user-interface
elements. In these cases, the screen reader isn't doing anything
special for Java; as far as the screen reader is concerned the Java application
or applet behaves in the same was as a native application, which the screen
reader knows how to deal with.
-
The second way is by utilizing the AccessBridge,
and configuring the Java VM to load the AccessBridge whenever a Java application
or applet is run. In these cases, the screen reader is specifically
using the Java Accessibility API to provide rich access to those Java applications
and applets which support accessibility. Note: a screen reader written
in the Java language would load directly into the Java VM, and would communicate
directly with Java applications and applets via the Java Accessibility
without using the AccessBridge.
Question Index
How do native (e.g. Windows and Macintosh)
screen magnifiers provide access to Java applications and applets running
on my system?
Screen magnifiers generally provide access to applications by magnifying
each of the pixels in the video buffer of the host computer (so one pixel
becomes four, or nine, or sixteen, etc.), with the physical screen showing
a portion of the magnified, virtual screen (which can pan back and forth,
up and down, "magnified portal" of the physical screen). In addition,
screen magnifiers track changes in mouse location, selection, text caret,
and the appearance/disappearance of menus and windows. In Java, this
is done in one of two ways:
-
The first way is by magnifying the video display as usual, and tracking
changes to the native/host user-interface elements in those cases
where the Java application or applet uses the AWT user-interface elements
and the Java VM in which the Java application or applet is running realizes
AWT user-interface elements as native/host user-interface elements.
In these cases, the screen magnifier isn't doing anything special for Java;
as far as the screen reader is concerned the Java application or applet
behaves in the same was as a native application, which the screen reader
knows how to deal with.
-
The second way is by magnifying the video display as usual, and further,
by utilizing the AccessBridge, configuring the
Java VM to load the AccessBridge whenever a Java application or applet
is run. In these cases, the screen magnifier is specifically using
the Java Accessibility API to track changes in those Java applications
and applets which support accessibility.
Question Index
What can I do to determine why my particular
assistive technology isn't working with a specific Java application or
applet?
Go through the following steps:
-
Is the Java application/applet written using AWT?
-
If so, then your problem probably lies with the Java VM you are using.
Switch to a Java VM that renders AWT controls via their native peers, such
as the Sun Microsystems reference Java VM, or the Java Plugin for Netscape
and Internet Explorer
-
If the application/applet isn't written using AWT, then is the Java application/applet
written using the Java Foundation Classes?
-
If so, then your problem may lies with the Java VM you are using.
Make sure you are using a Java VM that supports loading assistive technologies
- today only the Sun Microsystems Java VMs do this; in Java 2 Standard Edition it becomes
a formal part of the Java Platform specification, and all Java 2 Standard Edition compliant
Java VMs will support this.
-
Otherwise, your problem may lie with your assistive technology. Contact
the manufacturer of your assistive technology, and find out if they have
a version that supports the Java Accessibility API.
-
If the application/applet was written using neither AWT nor the Java Foundation
Classes, then the Java application/applet was probably not written to be
accessible.
-
Contact the manufacturer of the Java application/applet, and find out if
they have a version that supports the Java Accessibility API.
Question Index
I'm a Java developer. What should
I do to make my Java applications and applets accessible?
If you need to deliver an accessible Java applet or application
immediately, your only option is to use restrict your Java applet/application
to the AWT user-interface components. This will allow the existing
native screen access solutions to work with your Java applet or application
in most common Java VMs.
For the future, to provide the best access to users via assistive technologies,
and the most flexibility in the design of your user-interfaces, use only
those user-interface components which implement the Java Accessibility
API. The Swing user-interface classes which are part of the Java
Foundation Classes for JDK 1.1, and are built-in to Java 2 Standard Edition, implement
the Java Accessibility API. In fact, currently Swing is the only
user-interface toolkit which implements the Java Accessibility API.
If you want to use user-interface objects from any other toolkit (or ones
you create yourself), you will need to implement the Java Accessibility
API on those components. A number of books on the Java Foundation
Classes describe how to do this, including Java Foundation Classes by
Nelson (publisher McGraw-Hill), and Java Swing by Eckstein (publisher
OReilly & Associates). In addition to using only user-interface
controls which support the Java Accessibility API, you should make sure
that your Java application conforms to the IBM
Special Needs Systems guidelines on developing accessible Java applications.
In addition, if you are delivering an applet that uses the Java Accessibility
APIs in the near future, you must configure that applet to use the Java
Plugin, as the Java VM in the currently shipping versions of Netscape
and Internet Explorer do not support loading of assistive technologies
into the Java VM.
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