[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: Problem to read the entire screen on Sid with BRLTTY

Boris Daix <Boris.Daix@insa-lyon.fr> writes:

> Mario Lang <mlang@debian.org> writes:
> [...]
>> What exactly did you change?  I suggest trying out the readline interface,
>> which is line-based.
> I have some similar display troubles with modconf on woody : modconf
> seems to use whiptail.  Is "dialog" meaning "whiptail" in debconf
> config for sid ?

Hmm, I just had a look at debconf sources, and it appears that:
1. Debconf/FrontEnd/Dialog.pm uses either dialog or whiptail, depending on what
   is installed
2. On my system, when using dialog with debconf, I get the behaviour I
   described in the mail earlier.  I wonder if dialog on woody behaves the
   same, or if there is just some switch we are missing, and which got lost,
   which would activate proper cursors behaviour.
3. When I install whiptail, debconf starts to use it, and I see the following:
   The cursor appears exactly one line below the actually highlighted line
   in a select box.
   Using Tab moves between the buttons, and the list, as expected.

1 is a good thing :-), 2 should be investigated, and 3 should probably
be filed as a bug against whiptail, if that wasn't done already...

Further digging showed that dialog in sid appears to just not use
the cursor for highlighting list items.  I didn't find any command-line option
for either dialog or whiptail which would enable this.  Hmm, maybe this
should be filed as a wishlist item against dialog *and* whiptail.

> (I didn't have any troubles with debconf on woody, that seems to use
> dialog).

Strange, as said, dialog does not appear to do "The Right Thing" for me.
If you use dialog on woody manually, something like

$ dialog --menu "Hello" 10 50 6 id1 one id2 two id3 three id4 four id5 five id6 six

does the cursor follow the selection?

> I suspect a display bug from dialog or whiptail used with BRLTTY (I
> didn't test without BRLTTY).

I highly doubt that any brltty specific thing is involved here, it is just
related to how certain full-screen terminal programs handle the position
of the cursor.

>> Oh, I just took the time to check, and can now see what your problem probably
>> is.  debconf's dialog interface highlights items
>> in a select box with attribute colour.  You can only change between
>> the Buttons at the bottom (OK and Cancel, or Yes and No) using
>> the normal cursor.  I dont really remember if that was always this way,
>> since I'm quite adapted to attribute highlighting programs and tend to do the
>> "looking for the highlight" quite automatically.  You can do this
>> by changing brltty into attribute view mode, and look for the line
>> which is probably currently highlighted.  Then move the cursor up and down,
>> and watch the highlighted line move.  Do this until you're sure that it is
>> highlighting the item you actually want to select.  You might want to switch
>> between attribute and text mode several times to achieve this.  Sometimes,
>> this can also be done by using the attribute underlining mode of brltty, but
>> that only works in some cases, I didn't particularily check
>> if that works in debconf dialog though.
> Usually, <TAB> allows to change from display object to display object
> (from lists to checkboxes, buttons, etc).  If not, it should :-)

In whiptail, it behaves like that here, in dialog, it does not.

> But sure, the attribute mode of BRLTTY is very nice.
>> Hope this helps
>> P.S. to Boris: This should be explained in the HOWTO.
> You mean "choosing a good frontend with debconf&co" ?


> Sure.  I guess "attribute tips" are documented upstream.

That should be correct yes, OTOH, a short intro to the problem in general might
fit somewhere since we'll reference the problem several times I guess.  The
lynx.cfg SHOW_CURSOR:TRUE option for instance addresses the same issues.

  Mario | Debian Developer <URL:http://debian.org/>
        | Get my public key via finger mlang@db.debian.org
        | 1024D/7FC1A0854909BCCDBE6C102DDFFC022A6B113E44

Reply to: