Re: issues with X Window

[Paolo Molaro <lupus lettere unipd it>]

On Sat, Aug 21, 1999 at 01:01:24PM -0700, Ryan Shugart wrote:
> 1.  What is the likelyhood that an application developer would use the 
> toolkit instead of the low-level protocols?  I equate the statement, and 
> yes I do admit to beeing new to this, of tool kits and low-level 
> protocols the same as standard controls and custom controls designed in 
> Windows.  A lot of programmers use custom controls for whatever reason, 
> I'm wondering how often that happens in Linux?  

There are two issues here.
First, as of today, almost all of the applications are built using a 
toolkit: using the low-level interface is a pain. The few applications
that don't use a toolkit are of little interest because a powerful
application written without a toolkit is bound to disappear
(it's unmaintainable software). The only important applications built 
with the low-level interface are the window managers, but as long as they
conform to the Gnome WM hints, it's possible to drive them through an
external program.
Second: the issues relating custom controls (a control is called a
widget in the unix world).
A lot of programmers develop custom widgets for use in their applications.
Often these custom widgets use the low-level interface to perform their
duties, however, that doesn't mean the custom widgets are not
speech-interface friendly. This depends on the widget, the toolkit and the
design.
For example in the Gtk+ toolkit, there is a widget called GtkEditable:
this is a base widget for an editable area. Now, all the custom widgets
that derive (Gtk+ is an object-oriented library) from GtkEditable will
be automatically speech-enabled: this is the case for the GtkEntry and
GtkText widgets included with the library, as well as for the custom widget
that displays RTF used in the Go word processor.
Nothing stops a developer from using a different design that will make
using the program impossible for a blind, however.
Another example is gnumeric: the grid of the spreadsheet is drawn on
the screen by an highly specialized widget, but the design is good
and it takes very few changes to enable full eyes-free access.

> 2.  The toolkits you described are primarily used on the Gnome desktop 
> environment.  I recently read a survey published by Borland International 
> saying that  KDE and the QT tool kits were the prefered environment, and 
> GTK was second.  I'm not saying which is better, as I would have no clue 
> or experience, but this issue does need to be addressed if KDE is this 
> popular.  When you say that GTK has accessability features in it, how do 
> you mean?  Are you talking about GSpeech or is there actually something 
> in the toolkit libraries, perhaps equivilent to MSAA?  

Well, I think Gnome and KDE have, more or less, the same number of
developers. The applications available in Gnome have some direct
equivalent in KDE and vice versa (you may think there is a lot of
wasted efforts, but lets not start a flamewar on this here:-).
I'm a Gtk+ and Gnome developer and as such I'm addressing the issues
of accessibility with applications that use these libraries.
Doing a bit of research, however, I studied the Qt interface and
I didn't find the features needed to enable a speech and audio
interface. I'll be glad to be proved wrong, however.
I can give you the technical details, if asked, but
I won't comment on this further, because we seriously
risk a flamefest:-)

Back to Gtk.
I don't know what is MSAA, maybe it's an accessibility API
for M$ Wndows? I never programmed for windows, sorry.
Gtk doesn't have accessibility features in it, but its design
enables the development of an application-independent module
that gets automatically loaded with the application.
This module can listen to the application's events, access
the widget hierarchy and provide the audio and speech feedback.
A similar approach is possible with Xt/Motif using an external
program instead of a module that is loaded in the address space
of the application.

lupus

-- 
lupus debian org
Se devo emigrare in America, come mio nonno, prendo il tram!        [F.G.]
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