[BRLTTY] Improving the speech support of brltty

[Mario Lang]

Nicolas Pitre <nico at fluxnic.net> writes:

>> >4. Sometimes brltty only speeks the difference between two lines. Example:
>> >a test line
>> >a second test line
>> >If "a test line" is the last visible line for example in a text editor
>> >and you move the cursor to the next line, brltty only speaks "second"
>> >instead of "a second test line". If both lines are visible, it works.
>> >You also can test it by reading the keytable text file line by line.
>> >Could you fix this too?
>> 
>> I understand the issue, but what to do about it is an entirely different 
>> matter. The "problem" is that brltty just looks at the screen so it has to 
>> guess a lot. It's on my list, though.
>
> It is almost impossible to fix without saving more context lines around 
> the cursor area.  BRLTTY would have to "see" that some of the screen 
> content is scrolling up or down and treat the line content as a new line 
> even though the cursor position didn't change vertically.
>
> The same code could allow for a mode where the braille window moves up 
> or down automatically to follow the scrolling screen content.  That 
> would be very handy when reading through an IRC session for example, and 
> new messages keep on appearing at the bottom.

Indeed, this feature would be mightily handy when it comes to following
chat seessions of any kind.  I actually had a proof-of-concept already
implemented back in 2003, but the code was faar too ugly to be
submitted.  It worked though.  I basically kept an image of the previous
screen state, and calculated a scroll delta between -3 and +3 lines
from the previous to the current screen state.  It appeared to work nicely for IRC
at least.

-- 
CYa,
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