Re: [orca-list] Orca dev resource

[Michael Whapples <mwhapples aim com>]

Hello,
I think the more general accessibility questions have been answered. I 
will try and answer the bit on cross platform GUI toolkits.

While WX uses GTK+, it uses some custom controls to make it look similar 
with other platforms, so needs to provide appropriate accessible 
information about the control, which it fails to provide to ATK/at-spi. 
This then means that the control is not seen as what it is meant to be 
by orca.

Here are a few notes I have made on cross platform accessible GUI 
toolkits, unfortunately I think C++ is poorly served.

Java: there are two options. Java swing which requires a type of java 
access bridge on Linux (the java atk wrapper) or windows (the java 
access bridge). On Mac it just works with voiceover out of the box but 
Apple have deprecated their JVM and putting effort into OpenJDK, not 
sure what the accessibility will be for that.

The second alternative on Java is SWT (http://www.eclipse.org/swt) which 
uses native controls (in a similar way to WX but is actually accessible 
on all platforms), so is accessible with no access bridge technology.

Another alternative might be by using the .NET/mono system. There is a 
page on the mono project website which discusses GUI options (sorry I 
don't have the link to hand) but it seemed to say that the winforms 
system is accessible on windows and accessible on Linux when the access 
bridge for mono is installed. Unfortunately winforms according to that 
page is not accessible on Mac, but there is a way to work with 
objective-C libraries from mono so you can create a native GUI from mono 
on the Mac. I have no actual experience with mono, I have based all this 
on the page discussing GUI option on the mono website. Having said that, 
should accessibility on Linux not be good enough, you could create a 
native GUI as there is also GTK#, which I think does create perfectly 
accessible GTK applications (I think I have used at least one of those 
before).

Another option, which might be usable from C++, is the XUL stuff from 
mozilla. While mozilla products are usable and accessible on both 
windows and Linux, I have listed this last as I am most reluctant in 
suggesting it as generally I get the feeling that there always is a few 
accessibility bugs in mozilla products and I now cautiously upgrade to 
newer mozilla products because I dread what problems I will find in the 
new version (eg. I have just upgraded to thunderbird 3.3a3 but word echo 
while writing this message has broken, thunderbird 3.3A2 had its issues 
as backspacing lead to the wrong character being spoken, but 3.1.x had 
focus issues when new windows opened, etc).

I hope that is useful.

Michael Whapples
On -10/01/37 20:59, Alex Midence wrote:
> Good day,
>
> I wonder if someone might point me to a document where I might find
> something detailing how Orca approaches making an app accessible.
> I've been curious about this for some time.  I want to understand how
> some things can be accessible to it while others cannot.  The whole QT
> thing has me baffled, for instance.  If QT exposes all its controls
> and such with labels and things as it advertises in their site, how
> does that information elude ORca?  Also, WXwidgets is another thing.
> I've used a few wxwidgets apps in Windows recently and they worked
> pretty well for the most part.  Code::blocks is the latest thing I
> used and it was all right except for the rad tool.  Anyway, when I
> tried it in Gnome, Orca can't read the dialogs well for some reason
> and text entry fields in other things like Geany and even AbiWord
> which is gtk+ don't read back what is input.  Where is the break in
> communication with Orca and the software?  Is there any way to "show"
> Orca how to use other means for getting accessibility information
> besides at-spi?  I'm sorry for all the questions.  I really wish to
> understand.  If there's a page somewhere for me to browse where this
> stuff is explained in a few paragraphs, please let me know.  I'm
> learning c++ right now and would like to be able to write some apps
> that I can use cross-platform with a GUI without having to rewrite an
> interface each time I want to use it in another platform.  Gtk+ isn't
> accessible in Windows and wxwidgets isn't great in Linux, and QT is
> spotty in windows but not accessible currently in Gnome.
>
> Sorry for the length,
> Alex M