These keys have different sequences when using cursorkeys, while insert
and delete stay the same. If they are placed like this, libteken will
return NULL instead of a proper sequence for these characters.
xterm and cons25 have some incompatibilities when it comes to escape
sequences for special keys, such as F1 to F12, home, end, etc. Add a new
te_fkeystr() that can be used to override the strings.
scterm-sck won't do anything with this, but scterm-teken will use
teken_get_sequences() to obtain the proper sequence.
These strings often contain things like:
- Window titles.
- Extended key map functionality.
- Color palette switching.
We could look at these features in the future (if people consider them
to be important enough), but we'd better discard them now. This fixes
some artifacts people reported when using TERM=xterm.
Reported by: des@, Paul B. Mahol
It is quite inconvenient that if an application for xterm uses 256 color
mode, text suddenly starts to blink (because of ;5; in the middle).
We'd better just implement 256 color mode and add a conversion routine
from 256 to 8 color mode, which doesn't seem to be too bad in practice.
Remapping colors is done quite simple. If one of the channels is most
actively represented, primary colors are used. If two channels are most
actively represented, secondary colors are used. If all three channels
are equal (gray), it picks between black and white.
Reported by: Paul B. Mahol <onemda gmail com>
This means we can finally do things like VT100 box drawing when using
Syscons (8-bit characters). As far as I know, the only remaining issue
is the absense of proper escape sequences for special keyboard
characters (cursor, F1 to F12, etc) and xterm emulation should be ready
for general use.
Enabling xterm would have the following advantages:
- Easier possible migration to Unicode. cons25 termcap entries are very
8-bit centric. They use things like CP437 characters for box drawing,
etc.
- Better support for SSH'ing to other operating systems/devices. Most
switches use VT100-style admin interfaces.
- Reduced bandwidth, because applications can now use things like
scrolling regions.
- You can finally use applications like dtach(1) on both the console and
inside an xterm.
- Make xterm/cons25 support runtime configurable. This allows me to
share libteken between syscons and my new vt driver.
- Add a fix to print blanks after printing a double width character to
prevent rendering artifacts.
- Add some more utility functions that I use in the vt driver.
Right now libteken processes TF_REVERSE internally and returns the
toggled colors to the console driver. This isn't entirely correct. This
means that the bold flag is always processed by the foreground color,
while reversing should be done after the foreground color has been set
to a brighter version by the bold flag.
This is no problem with the syscons driver, because with VGA it only
supports 16 foreground and 8 background colors. My WIP console driver
reconfigures the graphics hardware to disable the blink functionality
and uses 16 foreground and 16 background colors. This means that this
driver will handle the TF_REVERSE flag a little different from what
syscons does right now.
I initially committed libteken to sys/dev/syscons/teken, but now that
I'm working on a console driver myself, I noticed this was not a good
decision. Move it to sys/teken to make it easier for other drivers to
use a terminal emulator.
Also list teken.c in sys/conf/files, instead of listing it in all the
files.arch files separately.
