Re: Introducing face in comments for various modes

[Heime via Users list for the GNU Emacs text editor <help-gnu-emacs@gnu.org>]

------- Original Message -------

On Monday, December 12th, 2022 at 8:49 AM, Thibaut Verron <thibaut.verron@gmail.com> wrote:

> Le lun. 12 déc. 2022 à 04:01, Heime <heimeborgia@protonmail.com> a écrit :
>
>> ------- Original Message -------
>> On Monday, December 12th, 2022 at 2:24 AM, Heime <heimeborgia@protonmail.com> wrote:
>>
>>> ------- Original Message -------
>>> On Sunday, December 11th, 2022 at 5:40 PM, Stefan Monnier via Users list for the GNU Emacs text editor help-gnu-emacs@gnu.org wrote:
>>>
>>> > BTW, there is a related convention in ELisp code where comments that
>>> > start in column 0 and which are introduced with 3 or more semi-colons
>>> > are considered sectioning headers (where ";;;" means a top-level
>>> > header, ";;;;" a subheader, ";;;;;" a subsubheader, ...).
>>> >
>>> > I'd be happy if Emacs were changed to highlighting those.
>>> >
>>> > Stefan
>>
>> If you are colourising "Sectioning Headers", ensure that vibrant and good contrast:
>>
>> 1) betweenthe text and the background;
>>
>> 2) and between a header, subheader, subsubheader, ...
>>
>> Use some colour metric (e.g. using the Web Content Accessibility Guidelines [WCAG]).
>>
>> Because I consistently see that developers almost never care (or have the skills)
>> to properly set up colours. Have suggested changing the colour scheme as described,
>> for "Org Headings" because they are indistinguishable against a dark background and
>> between a heading and its subheading. Applying such metrics have been turned down,
>> with the excuse that if I want them right, I have to work on emacs customisations
>>
>> myself, as the crappy colours are there to stay.
>
>> The colors of the standard themes are chosen with its (light) background in mind. If you change that background, it is not surprising that things fall apart.

Choosing colours with a light background in mind is the wrong approach because colours produce far greater visual
impact. But, a dark background also makes the pupil expand, which amplifies the impairment of those with astigmatism.

Rather, there there should be carefully chosen colour settings for both light and dark backgrounds.

>> It is not a new problem, but it doesn't mean that you have to customize all the individual faces yourself. Instead, you should look for a theme implementing
>> the colors you like, and install it. The responsibility for having consistent colors across all emacs fonts is on the theme designer. You can still tweak some
>> faces from there if you choose to of course.
>
> At any rate, Stefan's suggestion would not require making new design choices, as there are already faces designed for fontifying headers: outline-1, outline-2, etc.

Making a new design choice is a necessity if you want to move forward.

> Those faces are used by outline-mode, but not by outline-minor-mode (which emacs-lisp-mode uses to implement the ;;; comment headers) at the moment.

Which proves my point that changes are necessary. What needs to be done is for colour contrast metrics
to be taken seriously by all packages, rather than relying on some theme to fix the crappy default choices.

> Best wishes,
> Thibaut
>
>>> Yes. I use headings as you describe to identify sections of code that focus on a particular task. But I also wanted to have some lower level categorisation (within a function, say) to group some descriptions together.
>>>
>>> > Heime [2022-12-11 15:35:41] wrote:
>>> >
>>> > > The following uses `hi-lock` to change the foreground of comments matching
>>> > > a regexp. This is implemented for emacs-lisp files where comments start
>>> > > with ";;".
>>> > >
>>> > > I would like to extend this for other programming languages besides emacs-lisp
>>> > > files, using the relevant comment character automatically for that language.
>>> > >
>>> > > (defface elfa-face
>>> > > '((t :foreground "magenta"))
>>> > > "Face for comment headings.")
>>> > >
>>> > > (defun elfa-regexp (&optional actm)
>>> > > "Identify comment category ';; [Category]'."
>>> > > (highlight-regexp
>>> > > "^;;\s+\\[.+\\].*$" 'elfa-face))
>>> > >
>>> > > (defun elfa-category ()
>>> > > "TODO."
>>> > > (interactive)
>>> > > (add-to-list 'auto-mode-alist '("\\.el\\'" . hi-lock-mode))
>>> > > (add-hook 'emacs-lisp-mode-hook 'hi-lock-mode t)
>>> > > (add-hook 'hi-lock-mode-hook 'elfa-regexp))