Brltty and NVDA Interaction; only some buttons on Braille display recognized as NVDA input gestures. #4177
Comments
|
Comment 1 by DebeeArmstrong on 2014-06-05 17:22 |
|
Comment 2 by jteh (in reply to comment description) on 2014-06-06 04:04 Replying to DebeeArmstrong:
You say here that it scrolls fine, but later, you note that fwinlt and fwinrt don't work. Am I misunderstanding what you mean by "scroll" here?
Most of the BRLTTY commands don't map well to NVDA's commands, which is why there is so much unassigned. It'd be great if you could provide suggestions regarding currently unassigned BRLTTY commands that it would make sense to assign by default.
They're not reported by input help because if they were, you wouldn't be able to scroll within a long input help message in order to read it. They should, however, work in an editable text field or the like; they certainly did when I last tested with my display. Can you try assigning them to something ridiculous like report time? That way, we can work out whether these are truly being dropped for some reason.
If NVDA isn't seeing it, BRLTTY almost certainly isn't passing anything to NVDA. This is something you'd need to work with the BRLTTY developers to understand/resolve. When you say other screen readers see it, do you mean other screen readers via BRLTTY or do you mean native screen reader drivers? |
|
Comment 3 by DebeeArmstrong on 2014-06-06 05:14 |
|
Comment 4 by jteh on 2014-06-06 05:37 You can test BRLTTY in Windows without NVDA by setting NVDA to no braille (or exiting NVDA) and opening a command console (e.g. type cmd in the Windows Run dialog). |
|
cc @Adriani90 |
|
@DebeeArmstrong have you tested BRLTTY and BRL API under Windows as suggested by @jcsteh in his comment above? The documentation is quite good actually. For an example how it works together with a Screen Reader, see e.g. the chapter "sharing a Braille Display with a Screen Reader". There is an example of how Jaws works in this construct. The last changes in BRLTTY and BRLAPI can be found here: Basically, BRLTTY is a universal toolkit containing most Braille Display Drivers and text / contracted tables. It is actually something like Liblouis + Drivers. And additionally, it is something like the Bridge between the screenreader, the braille Display driver and the Braille Display itself. So any hardware developer can write a Driver for BRLTTY which is bein included in there. Additionally, every Software developer can learn his or her application to communicate with the BRLAPI and the Display Driver. BRLTTY is commonly used by almost all Braille Display Producers. BRLAPI is actually a Driver for BRLTTY, something like a helper or a control Client which allows Software developers to send Output to Braille in a specific manner. cc: @bramd, @michaelDCurran |
|
As we can't seem to reach the original author, closing this for now to clear up our backlog a bit. If this is still an issue to someone, feel free to reach out and we can reopen/reassess priority, though it won't be higher than a p4 or even a won't fix. |
Reported by DebeeArmstrong on 2014-06-05 17:04
TeleSensory PowerBraille 40 (PB40) works beautifully under Brltty in Linux. In NVDA, it displays and scrolls fine, but either NVDA, Brltty, Brlapi or the TSI display driver in Brltty are not recognizing all the buttons.
This might need to be fixed upstream, or perhaps there's a user table that can be edited. Further documentation would be appreciated. Perhaps a wiki article on how Brltty, Brlapi, the individual Braille display drivers and NVDA all co-exist.
See my related documentation bug: #4176 (Invalid (depricated) link in documentation.)
http://community.NVDA-project.org/ticket/4176#ticket
I tested with three separate PB40s on three different Windows 7 computers, all connected to hardware (not USB) serial ports. The results were identical. I also switched displays so each computer was tested once with each different display.
In most cases, a button was seen by NVDA but not assignned, so I assigned it myself under input gestures.
To test, I got the Brltty button names with input help Insert-1. I also used Preferences-Input gestures, to assign as many of the buttons as NVDA could detect when prompted to enter an input gesture.
The remainder of this report contains a list of the buttons that do work properly, followed by a list of those that either are not recognized or are only partly seen by NVDA.
In the below list I give the Brltty button name as reported by NVDA followed with the assignment, followed by what physical button(s) it's mapped to on my PB40.
Buttons it does recognize:
Brltty LNUP: moves display to prev line; mapped to right rocker up
Brltty lndn: moves display to next line; mapped to right rocker down
Brltty prefmenu: assigned myself successfully; mapped to pressing right and left buttons together
Brltty csr_jmpvert: assigned myself successfully; mnapped to pressing left and right rockers down together
Brltty Home: assigned myself successfully; mapped to concave button
Brltty csrtrk: assigned myself successfully; mapped to convex button
Brltty freeze: assigned myself successfully; mapped to pressing concave and convex buttons together
Brltty mute: assigned myself successfully; mapped to right rocker up and right button pressed together
Brltty lnbeg: assigned myself successfully; mapped to left button and left rocker up pressed together
Brltty say_line: assigned myself successfully; mapped to right button and right rocker down pressed together
Brltty LNMED: assigned myself successfully; mapped to right button and left rocker up pressed together
Brltty top_left: assigned myself successfully; mapped to left button and right rocker pressed together
Brltty bot_left: assigned myself successfully; mapped to left button and right rocker down pressed together
Brltty Paste: assigned myself successfully; mapped to left rocker down and concave pressed together
Brltty Back: assigned myself successfully; mapped to left rocker up and concave pressed together
Brltty windn: assigned myself successfully; mapped to left rocker down and convex pressed together
Brltty winup: assigned myself successfully; mapped to left rocker up and convex pressed together
Brltty prdifly: assigned myself successfully; mapped to right rocker down and concaved pressed together
Brltty nxdifly: assigned myself successfully; assigned to right rocker down and concave pressed together
In this list, I've given button names where NVDA could report them. In most cases, it didn't see the button, so I only report the physical button on the device.
buttons not recognized:
Brltty fwinlt: scrolls braille back; should be assigned to the left button, could not assign myself
Brltty fwinrt: scrolls display forward; should be assigned to the right button, could not assign myself
PB left rocker up: not seen by NVDA at all; cannot assign
Pb left rocker down: not seen by NVDA at all; cannot assign
PB left and right rockers pressed up together: not seen at all by NVDA; cannot assign
PB Left button and left rocker down pressed together: not seen at all by NVDA; cannot assign
PBRight button and left rocker down pressed together: not seen at all by NVDA; cannot assign
The left and right buttons, fwinlt and fwinrt respectively, were listed in the tree view for Braille input gestures for scrolling Braille back and forward. They were also recognized when attempting to assign them with the Add button. However they never performed any assigned function and were not seen by input help. Removing and adding them again put them back in the list of input gestures, but NVDA could not actually see these buttons being pressed on the display.In other words, NVDA could only see these buttons being pressed when actually in the Input gestures dialog, when user is prompted to enter an input gestures.
The large left rocker bar, when pressed up and down without pressing any other buttons, was never recognized by NVDA though Brltty in Linux and other screen readers see it , and its function can easily be reassigned with other screen readers.
The text was updated successfully, but these errors were encountered: