Re: some console code checked in

[Marcus Brinkmann]

On Mon, Mar 18, 2002 at 03:36:03PM +0100, Niels Möller wrote:
> I have no idea how "scroll-region" escape codes should be implemented
> on a text-to-speech terminal (my best guess is "not at all"),

Of course it would not be supported.

> If every device has some pointers for the basic operations, strange
> devices can leave some of the pointers as NULL, and for each NULL
> operation, the console code has to figure out how to do without that
> feature.

This scheme already exists, but at the application level.  It is called 
terminfo(5)
and works very well. I think it would be a mistake to reimplement it, just 
poorer.

Instead, I thought passing everything through to the device, and let the
device figure out what to do with it, and require the user to set the right
TERM variable, would be best.  Of course, for the important cases where the
capabilities are (mostly) identical, we should use the same terminfo entry
and the same intermediate layer (what I suggested).

For displays supporting scrolling etc:

[ console abstraction ]
[ virtual console 1 ] [ virtual console 2 ] ...
[ display driver ]
[ generic display driver escape sequence handling ]
[ display driver's support functions like scrolling ]

For other displays:
[ console abstraction ]
[ virtual console 1 ] [ virtual console 2 ] ...
[ display driver ]

Thanks,
Marcus

-- 
`Rhubarb is no Egyptian god.' Debian http://www.debian.org brinkmd@debian.org
Marcus Brinkmann              GNU    http://www.gnu.org    marcus@gnu.org
Marcus.Brinkmann@ruhr-uni-bochum.de
http://www.marcus-brinkmann.de