[texhax] LyX for Windows screen reader usability

Uwe Lueck uwe.lueck at web.de
Wed Nov 10 14:20:11 CET 2010

Hi Paul,

as to screen readers showing TeX's output of, e.g., 
from $\frac{x}{y^2}$: what do you expect? I have typeset it, 
the outcome is a bar with an `x' above and an `y' with 
superscript `2' below. What should a screen reader tell about it?
I have copied it from Adobe Reader 8 under Linux (Fedora 8, 
Linpus Lite) into a .txt file that reads


(one line contains an `x', the next line contains 2', 
 no indication of the bar and the position of the `2'). 
What could a screen reader do instead? 

In this special case, a good text representation could be 
x/(y^2), but that is very different what LaTeX does, 
rather reminding of what you could type on a scientific calculator.

Well, this seems to go into the MathML direction I don't know much about, cf. 


A math formula really has a graphic character (as soon it 
gets some complexity), and one approach for displaying 
formulas on the web indeed is presenting them as graphic 
images (e.g., PNG). There is a different approach: constructing 
formulas in pure HTML, Wikipedia tries this some way; 
some commercial program goes much farther this way. 
But then still I wonder what a screen reader should tell 
about the sizes, shapes, and positions of the glyphs. 

A fraction may contain other fractions in its denominator, 
and with TeX you can choose whether the contained 
fractions are typeset in text or in script size -- what should 
the screen reader tell about sizes, how?

In another thread we learnt that due to a bug, certain 
symbols in certain math formulas are not placed at the 
vertical position where they should be. Should a screen 
reader be able to tell this?

I have wondered if there could be a device that represents 
pixels by needles that are pushed out of a surface for 
representing black ink, so you could feel the shape 
of glyphs and formulas with your fingers.  



"Paul Stanley" <paulrichardstanley at gmail.com>, 09.11.2010 14:42:54:
> I have heard of such things and what I'd like to know is, is the 
> LaTeX source *interpreted*, as it were, live in the edit window? for 
> example, say, I wanted to typeset a fraction such as `\frac{x}{y^2}', 
> would I be able to *see* the result of my code immediately, that is 
> to say, without having to run the LaTeX compiler separately?

"Paul Stanley" <paulrichardstanley at gmail.com>, 10.11.2010 01:22:09:
>I must admit Windows programming isn't something I'm very familiar with.
>Is this a necessary part of designing a LaTeX editor?
>At 23:50 09/11/2010, you wrote:
>>On 9 November 2010 Paul Stanley wrote:
>>  > Hi folks
>>  > I appreciate this may not be strictly on-topic but I think it's
>>  > useful information to others in my position.
>>  > LyX-1.6 (for Windows) is, in short, unusable with a screen reader.
>>Hi Paul,
>>I suppose that screen readers can gather the text only if font
>>rendering is done by operating system facilities which provide a hook
>>for them.
>>If a program is using its own font rendering library, I suppose that
>>there is no such hook, i.e. the text is only visible to the program
>>itself, which then creates bitmaps of the glyphs in order to display
>>them on screen.
>>I fear that most free programs are using free libraries like freetype
>>but screen readers on Windows hook into libraries provided by Microsoft.

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