bug#59141: 28.1.90; Face :extend when all the line but trailing \n is invisible

["Kévin Le Gouguec" <kevin.legouguec@gmail.com>]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Kévin Le Gouguec <kevin.legouguec@gmail.com>
>> Cc: Ihor Radchenko <yantar92@posteo.net>,  59141@debbugs.gnu.org
>> Date: Wed, 09 Nov 2022 23:19:42 +0100
>> 
>> Eli Zaretskii <eliz@gnu.org> writes:
>> 
>> > I said many times that people shouldn't willy-nilly use the :extent
>> > attribute, just because it looks cooler in some situation.  The intent
>> > was and still is for faces not to have this attribute set, with very
>> > few very special exceptions, like the 'region' face.  But people don't
>> > listen...
>> 
>> FWIW, my motivation for setting :extend on outline headings doesn't stem
>> from aesthetics.
>> 
>> Clearly delineating "sections" with colored backgrounds that span the
>> whole window width is a neat visual aid, IME;
>
> Do you see a contradiction between the last two sentences?  Aren't
> "neat visual aid" and "aesthetics" synonyms?

"Visual aid" evokes accessibility and ergonomics; "aesthetics" are only
tangentially related to those concepts, in my understanding at least.  I
would not consider them synonyms, FWIW.

AFAIU, accessibility and aesthetics are both connected to individual
preferences, and they're not completely independent; I still believe
that "making sections easier to spot" and "making sections prettier"
should not be conflated.

>> So this "visual aid" aspect is why I suspect reporters think being able
>> to :extend outline heading backgrounds is about as desirable as
>> :extending the hl-line or region faces, and it's a shame it breaks down
>> when folding.
>
> My suggestion is to use "other means" for such cues.  Especially if
> you want to have that in modes that hide text, such as Org.  The
> :extend attribute wasn't intended to support this usage.

Sure, and I'll take this opportunity to thank everyone who's worked on
outline.el and icons.el these past months - margin indicators and
icon-backed buttons are very welcome additions!

>> It's not a critical feature to be missing, and that motivation does not
>> invalidate the implementation challenges you highlight.  I just wanted
>> to spell this point out FTR, as I didn't feel "it looks cooler" conveyed
>> it quite as convincingly 🙂
>
> I don't see the difference, really.  "Cool" isn't a derogatory
> adjective, or at least I didn't mean it to be so.

My point wasn't to denounce derogatoryness but to try to reframe the
motivation for the feature.  "Cool" does not suggest forethought,
"willy-nilly" does not suggest purpose; I think people who want
:extended backgrounds lack for neither forethought nor purpose.

(And I felt like it was worth making that point because it was not
discussed the last time around, AFAIR.  In bug#52587, I mostly rambled
about the “abstract sense of what is and is not "part" of the subsection
to hide”; I don't recall us going into aesthetics nor accessibility)

Wouldn't want to belabor the point though; if I'm the only one who
thinks this distinction is any use, that's fair; apologies for the
noise.