[nfbcs] An Analysis of JAVASWT Classes

Steve Jacobson steve.jacobson at visi.com
Wed Jan 18 21:21:26 UTC 2012 

John,

The eye-opener here for me is that I always thought that a JAVA program could be written however one 
wants to write it but just make sure to use SWT for the user interface.  What his note said that was new 
to me is that if you use SWT, it affects ones ability to use other JAVA classes to do things that are 
not related to UI.  For example, he would like to use other JAVA classes to handle the creation and 
display of the drawings that are made, but he can't without doing a lot of modification to class 
libraries that isn't always even possible.  If one is writing a braille translator, one knows from the 
outset that that it has to be accessible.  However, if one has a large application made of processes 
already using JAVA classes, changing UI components to SWT could impact other processes that one would 
not normally need to change for accessibility.  In some cases, therefore, the effort to make an 
application accessible if far greater than it appears from the outside.

I believe that John is right that our most effective approach so far has been to magnify the effect of 
our small market by getting laws and regulations in place that reuire accessibility in certain cases.  
However, in terms of expectations, and perhaps even where we apply pressure, we need to understand where 
the difficulties lie in making something accessible.  

Best regards,

Steve Jacobson

On Wed, 18 Jan 2012 15:02:48 -0600, John J. Boyer wrote:

>Right. I am simply avoiding anything that uses swing or the awt classes, 
>since they are inherently inaccessible. However, there is no real 
>alternative to SWT if you want to develop a cross-platform Java 
>aplication. 

>I'm a pragmatist. 

>John

>On Wed, Jan 18, 2012 at 01:50:56PM -0600, Steve Jacobson wrote:
>> John,
>> 
>> I don't think you are addressing his point, though, that it is hard to integrate SWT classes with 
many other JAVA classes.  It is likely you are not having to do that with Braille bBlaster, but I could 
be wrong.  If I 
>> am assuming incorrectly, let me know.
>> 
>> Best regards,
>> 
>> Steve Jacobson
>> 
>> 
>> On Wed, 18 Jan 2012 11:00:03 -0600, John J. Boyer wrote:
>> 
>> >There is a version of SWT for each major platform. All you have to do is 
>> >include the correct version in the lib subdirectory of your application. 
>> >That is the approach we are lulsing in BrailleBlaster. We also have some 
>> >native C libraries, which must be compiled for each platform, so SWT is 
>> >no big deal. 
>> 
>> >There are limits to "compile once, run anywhere", IMHO. SWT will 
>> >continue to be the best approach until <compile once, run anywhere," is 
>> >applied to operating systems.
>> 
>> >John
>> 
>> >On Wed, Jan 18, 2012 at 09:48:53AM -0600, Steve Jacobson wrote:
>> >> Dr. Richard Baldwin is working on a program that allows blind persons to draw based on commands 
and he 
>> >> has posted a number of messages on our BlindMath list.  I have long been frustrated by the 
accessibility 
>> >> of JAVA apps and one of my responses has been why don't more apps just use the SWT classes that 
cause 
>> >> JAVA apps to use the native controls of the operating system under which they run.  Dr. Baldwin 
has used 
>> >> these classes in his drawing program, and the results are pretty good.  However, he discussed the 
>> >> difficulty of doing this in a note to the Blind Math list which I am including below.  I found his 
>> >> comments to be both eye-opening and discouraging.
>> >> 
>> >> ==================BEGIN FORWARDED MESSAGE==================
>> >> From: Richard Baldwin <baldwin at dickbaldwin.com>
>> >> Date: Sun, 8 Jan 2012 07:59:46 -0600
>> >> To: "Steve Jacobson" <steve.jacobson at visi.com>
>> >> Subject: Re: [Blindmath] How useful is a GUI to blind users?
>> >> 
>> >> 
>> >> You wrote: " Is it possible to use the SUN image API for the graphic
>> >> presentation portions of the program and use SWT for the user controls? "
>> >> 
>> >> Just about anything is possible when enough programming effort is applied.
>> >> What you suggest is possible but difficult to achieve in a reliable way,
>> >> and quite a lot of extra programming effort is required to achieve it.
>> >> However, that is not really the issue. The issue is that the use of the SWT
>> >> precludes the use of many existing Java class libraries.
>> >> 
>> >> The great promise and benefit of object-oriented programming is "reuse,
>> >> don't reinvent." The great power of the Java programming environment is the
>> >> existence of massive class libraries that can be re-used to program with
>> >> relative ease those things that would otherwise be very difficult.
>> >> 
>> >> The bottom line is that many existing Java class libraries cannot be
>> >> "re-used" with the SWT without a major programming effort to modify those
>> >> libraries. Even with a major programming effort, library modification is
>> >> possible only when the author of the library is willing to divulge the
>> >> source code for the library. Sometimes source code is available and
>> >> sometimes it is not available.
>> >> 
>> >> IBM's approach with the SWT seems to have been "reinvent, don't reuse."
>> >> They should not claim that their programming environment is Java simply
>> >> because the compiled output will execute in a Java Virtual Machine. (The
>> >> compiled output of JYthon and several other programming languages will also
>> >> execute in a Java Virtual Machine but they are not Java.) IBM should have
>> >> renamed their programming environment JBM or something like that to make it
>> >> clear that SWT was never intended to be a member of the "write once, run
>> >> anywhere" family of Java products and was never intended to be compatible
>> >> with standard Java class libraries.
>> >> 
>> >> Microsoft did something similar a few years back, but after several years
>> >> of floundering around with "Microsoft Java," they finally renamed their
>> >> programming environment C# to distinguish it from Java. And, by going down
>> >> an independent path from Java, developing their own class libraries, and
>> >> not claiming any degree of compatibility with Java, C# has become a very
>> >> respectable programming environment in its own right. IBM should do the
>> >> same.
>> >> 
>> >> Welcome to the world of JBM.
>> >> 
>> >> Thanks for the response,
>> >> Dick Baldwin
>> >> 
>> >> On Sun, Jan 8, 2012 at 5:55 AM, Larry Skutchan <lskutchan at aph.org> wrote:
>> >> 
>> >> > Is it possible to use the SUN image API for the graphic presentation
>> >> > portions of the program and use SWT for the user controls? It doesn't seem
>> >> > like either way provides any accessibility advantages to the graphical
>> >> > drawing, manipulation, or interpretation portions of the interface, yet SWT
>> >> > provides accessibility to those controls that do offer clear advantages for
>> >> > both blind and sighted users.
>> >> 
>> >> 
>> >> > On Jan 7, 2012, at 10:16 PM, Richard Baldwin wrote:
>> >> 
>> >> > > You wrote: " I thought there was generally a well-established principle
>> >> > in
>> >> > > software development that it is best to implement a set of functionality
>> >> > in
>> >> > > a way that can be connected to various presentations of user interface"
>> >> > >
>> >> > > You are probably speaking of something called the model-view-control
>> >> > > pattern, which is great in theory, but rarely exists to the full extent
>> >> > > possible in practice.
>> >> > >
>> >> > > Getting down in the weeds, here is an example of marrying Sun Java
>> >> > graphics
>> >> > > with SWT Java graphics. Standard Sun Java provides the capability to use
>> >> > > the Sun Graphics2D API to create graphics on an off-screen Image object.
>> >> > > Sun Graphics2D is a fairly extensive and powerful API.
>> >> > >
>> >> > > The SWT makes it possible to use SWT graphics (which are entirely
>> >> > different
>> >> > > from the Sun Graphics2D API) to create off-screen graphics on an Image
>> >> > > object. In my opinion, SWT graphics are less extensive and less powerful
>> >> > > than the Sun Graphics2D API, but that is just an opinion that others may
>> >> > > disagree with. There is no disagreement, however, that the two are
>> >> > > different and are incompatible.
>> >> > >
>> >> > > There is also no disagreement that an SWT Image object is different from
>> >> > a
>> >> > > Sun Image object, and the two are incompatible. Rather than building on
>> >> > the
>> >> > > Sun Image class, IBM elected to invent their own Image class in the SWT.
>> >> > > This was a decision that apparently had nothing to do with the use of the
>> >> > > native GUI components because it is not a GUI issue. Thus,
>> >> > > incompatibilities between Sun Java and SWT Java go far deeper than simply
>> >> > > the use of native GUI components or lightweight GUI components. They go
>> >> > > very deep into the guts of the programming environment.
>> >> > >
>> >> > > When graphics are developed using Suns Graphics2D API, which is the case
>> >> > > with the majority of existing Java graphics libraries, the display of
>> >> > that
>> >> > > graphic information on an SWT Composite object, requires that first, it
>> >> > is
>> >> > > necessary to gain access to the Sun Image object (if possible), then it
>> >> > is
>> >> > > necessary to reformat and transport the graphics information from the Sun
>> >> > > Image object to an SWT Image object, and then it is necessary to display
>> >> > > the graphics information on an SWT Composite object.
>> >> > >
>> >> > > To begin with, the graphics data on aSun Image object may, or may not be
>> >> > > accessible to the programmer, depending on the design of the graphics
>> >> > > library. Even if the graphics data on the Sun Image object is accessible
>> >> > > (with or without modifying the library), the task of reformatting and
>> >> > > transporting that data to an SWT Image object, solely for purposes of
>> >> > > display, is tedious, time consuming, and can result in a lack of
>> >> > > responsiveness for graphics-intensive programs.
>> >> > >
>> >> > > Of course, it is always possible to modify a library if source code for
>> >> > the
>> >> > > library is available, but to a large extent, that defeats the purpose of
>> >> > > OOP and class libraries. It can also be very difficult in some cases.
>> >> > >
>> >> > > Dick Baldwin
>> >> > >
>> >> > > On Sat, Jan 7, 2012 at 7:57 PM, Jamal Mazrui <empower at smart.net> wrote:
>> >> > >
>> >> > >> Some miscellaneous points are as follows.
>> >> > >>
>> >> > >> There were text mode, screen oriented user interfaces before graphical
>> >> > >> user interfaces, e.g., WordPerfect 5.1 was a highly popular DOS-based
>> >> > word
>> >> > >> processor among blind people.  In fact, I think we were, overall, more
>> >> > >> productive with it than any GUI word processor, like MS Word,  or
>> >> > >> command-oriented word processor, like VIM.
>> >> > >>
>> >> > >> Those text mode, screen oriented interfaces could be highly accessible
>> >> > >> with a screen reader because it knew precisely what character (and
>> >> > color)
>> >> > >> was located in every position of a grid with 25 rows and 80 columns.
>> >> >  The
>> >> > >> point of focus was also precisely known -- what later became the caret
>> >> > in a
>> >> > >> GUI.  Accessibility of GUIs has been a problem in large part because a
>> >> > >> screen reader has had to build an "off screen model" of what text is on
>> >> > the
>> >> > >> screen, since by the time text is displayed on the screen, it is pixels
>> >> > not
>> >> > >> characters.  A GUI screen reader has traditionally had to intercept
>> >> > every
>> >> > >> operating system call that writes to the screen, remember where the
>> >> > writing
>> >> > >> occurred, and adjust the model every time some other OS call implies a
>> >> > >> change in the visual presentation.
>> >> > >>
>> >> > >> This process has been error prone, thus necessitating the need for an
>> >> > >> accessibility API by which the screen reader can interrogate the screen
>> >> > at
>> >> > >> any time.  Unfortunately, comprehensively implementing that
>> >> > accessibility
>> >> > >> API, on both the application and screen reader side, has also been error
>> >> > >> prone.  There are other reasons as well why GUIs have been difficult,
>> >> > >> including the emphasis on a mouse for input rather than the keyboard --
>> >> > the
>> >> > >> former usually requiring fine eye-hand coordination to be practical.
>> >> > >>
>> >> > >> Blind people, like sighted people, have a range of cognitive abilities.
>> >> > >> Some find the memorization of commands and syntax, which is generally
>> >> > >> required by a command-line interface, to be challenging and
>> >> > frustrating, as
>> >> > >> compared to a GUI and screen reader combination implemented accessibly,
>> >> > >> which support much more choice selection and safe exploration of options
>> >> > >> before executing a task.  Often, the most productive application will be
>> >> > >> one that offers both an accessible GUI for typical use and a
>> >> > well-designed
>> >> > >> command line interface for advanced use.
>> >> > >>
>> >> > >> I am puzzled why Swing seems to be so integrated into popular Java
>> >> > >> libraries.  Do they not separate visual display from underlying
>> >> > >> functionality?  I thought there was generally a well-established
>> >> > principle
>> >> > >> in software development that it is best to implement a set of
>> >> > functionality
>> >> > >> in a way that can be connected to various presentations of user
>> >> > interface
>> >> > >> -- unless, of course, the library is specifically targeted to building
>> >> > user
>> >> > >> interfaces.
>> >> > >>
>> >> > >> Regarding SWT, it is cross platform, not Windows only, though different
>> >> > >> binary files have to be distributed with other platforms.  I am a fan of
>> >> > >> wxWidgets, but agree that SWT is clearly more established in the Java
>> >> > >> community, and do not see any advantage that wx-based GUIs would offer
>> >> > over
>> >> > >> SWT.  Both GUI libraries are essentially wrappers over native controls
>> >> > of
>> >> > >> the platform.  Such controls tend to be the most accessible because they
>> >> > >> implement the primary accessibility API of the platform, being build by
>> >> > the
>> >> > >> developer of both the platform and accessibility API.
>> >> > >>
>> >> > >> Jamal
>> >> > >>
>> >> > >>
>> >> > >>
>> >> > >> ______________________________**_________________
>> >> > >> Blindmath mailing list
>> >> > >> Blindmath at nfbnet.org
>> >> > >> http://nfbnet.org/mailman/**listinfo/blindmath_nfbnet.org<
>> >> > http://nfbnet.org/mailman/listinfo/blindmath_nfbnet.org>
>> >> > >> To unsubscribe, change your list options or get your account info for
>> >> > >> Blindmath:
>> >> > >> http://nfbnet.org/mailman/**options/blindmath_nfbnet.org/**
>> >> > >> baldwin%40dickbaldwin.com<
>> >> > http://nfbnet.org/mailman/options/blindmath_nfbnet.org/baldwin%40dickbaldwin.com
>> >> > >
>> >> > >>
>> >> > >
>> >> > >
>> >> > >
>> >> > > --
>> >> > > Richard G. Baldwin (Dick Baldwin)
>> >> > > Home of Baldwin's on-line Java Tutorials
>> >> > > http://www.DickBaldwin.com
>> >> > >
>> >> > > Professor of Computer Information Technology
>> >> > > Austin Community College
>> >> > > (512) 223-4758
>> >> > > mailto:Baldwin at DickBaldwin.com
>> >> > > http://www.austincc.edu/baldwin/
>> >> > > _______________________________________________
>> >> > > Blindmath mailing list
>> >> > > Blindmath at nfbnet.org
>> >> > > http://nfbnet.org/mailman/listinfo/blindmath_nfbnet.org
>> >> > > To unsubscribe, change your list options or get your account info for
>> >> > Blindmath:
>> >> > >
>> >> > http://nfbnet.org/mailman/options/blindmath_nfbnet.org/lskutchan%40aph.org
>> >> 
>> >> 
>> >> > _______________________________________________
>> >> > Blindmath mailing list
>> >> > Blindmath at nfbnet.org
>> >> > http://nfbnet.org/mailman/listinfo/blindmath_nfbnet.org
>> >> > To unsubscribe, change your list options or get your account info for
>> >> > Blindmath:
>> >> 
>> >> > http://nfbnet.org/mailman/options/blindmath_nfbnet.org/baldwin%40dickbaldwin.com
>> >> 
>> >> 
>> >> 
>> >> 
>> >> -- 
>> >> Richard G. Baldwin (Dick Baldwin)
>> >> Home of Baldwin's on-line Java Tutorials
>> >> http://www.DickBaldwin.com
>> >> 
>> >> Professor of Computer Information Technology
>> >> Austin Community College
>> >> (512) 223-4758
>> >> mailto:Baldwin at DickBaldwin.com
>> >> http://www.austincc.edu/baldwin/
>> >> _______________________________________________
>> >> ===================END FORWARDED MESSAGE===================
>> >> 
>> >> 
>> >> 
>> >> 
>> >> _______________________________________________
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>> >> http://nfbnet.org/mailman/options/nfbcs_nfbnet.org/john.boyer%40abilitiessoft.com
>> 
>> >-- 
>> >John J. Boyer; President, Chief Software Developer
>> >Abilitiessoft, Inc.
>> >http://www.abilitiessoft.com
>> >Madison, Wisconsin USA
>> >Developing software for people with disabilities
>> 
>> 
>> >_______________________________________________
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>> 
>> 
>> 
>> 
>> 
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>-- 
>John J. Boyer; President, Chief Software Developer
>Abilitiessoft, Inc.
>http://www.abilitiessoft.com
>Madison, Wisconsin USA
>Developing software for people with disabilities


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