Re: Request for new terminfo capability (DECCARA extended)

[Kovid Goyal]

On Wed, Feb 07, 2018 at 04:14:40AM -0500, Thomas Dickey wrote:
> On Wed, Feb 07, 2018 at 08:23:48AM +0530, Kovid Goyal wrote:
> > Hi,
> > 
> > In light of the various problems with background color erase, as
> > documented here: 
> > http://invisible-island.net/ncurses/ncurses.faq.html#bce_mismatches
> > I'd like to propose a new boolean capability for terminfo named (something 
> > like)
> > sgr_region.
> > 
> > If set, the terminal emulator should implement the extended DECCARA
> > escape code, as described here:
> > https://github.com/kovidgoyal/kitty/blob/master/protocol-extensions.asciidoc#setting-text-styles-colors-in-arbitrary-regions-of-the-screen
> > and the original DECCARA from the VT 510:
> > https://vt100.net/docs/vt510-rm/DECCARA.html
> > This allows applications to set any SGR attribute in an arbitrary
> > region of the screen, by sending a simple CSI code that starts with the
> > region co-ordinates followed by the SGR code(s) to set. 
> 
> DECCARA doesn't have much relationship with bce...

The relationship is pretty obvious, but let me spell it out.  bce is an
underspecified feature, that is nonetheless relied on by a few
applications, and causes endless headaches, just google for issues
related to bce, or read your own FAQ. DECCARA allows you to avoid using
it, thereby hopefully moving the terminal emulator space forward.

-- 
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Dr. Kovid Goyal 
https://www.kovidgoyal.net
https://calibre-ebook.com
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