Re: Consistent face for keys in *Help* and `substitute-command-keys'

[Stefan Kangas <stefan@marxist.se>]

Juri Linkov <juri@linkov.net> writes:

> I completely agree.  I retained "grey85" that was used for foreground,
> but it's not suitable for background.  But OTOH, "grey95" is almost
> indistinguishable from the default white background.

The change is fine, but I have a nit/question:

On my screen grey95 is clearly distinguishable while grey90 is too dark
for comfort.  You report something quite different from that, which
makes me think that this is perhaps not simply down to taste or
mere subjective opinion.

Could this be associated with things like differences in luminosity of
our physical monitors, brightness/contrast settings, X gamma settings
and what have you?

Is there a way to find an objective measure to decide the better default
here?  Or should we just make both of us slightly (un)?happy by setting
the color to e.g. grey92, assuming that the mean between our findings is
the most scientific we can hope to get and will work somewhat okay-ish
everywhere, and call it a day?

> GitHub and GitLab use "grey90" for light and "grey25" for dark,
> so I changed now accordingly.

BTW, where do you find "grey90"?  They seem to use a lighter background
than that on the pages I've been looking at.

Here I see #fafbfc for keys, which is between gray98 and gray99, with an
added outline:

https://docs.github.com/en/github/getting-started-with-github/keyboard-shortcuts

Here I see #f0f0f0 for keys, which is gray94, with no added outline:

https://docs.gitlab.com/ee/user/shortcuts.html

> When trying to use the style :background "grey90"
> :box (:line-width 2 :style released-button)
> the look is much nicer, but at the cost of wasting more vertical space
> for higher lines.

The look of that is not too bad.  It looks slightly dated perhaps (the
latest trend is to keep things flat rather than fake 3D) but at least it
is extremely clear.  It is arguably a more user-friendly choice.

I'm not sure that I notice any wasted vertical pixels (we are talking 1
or 2 of them or something like that, right?) but I didn't measure it.

(This would likely look even better if we could allow for a pixel or two
of vertical space between the keys to allow them more space to breathe.
But I can't find any way to specify something like that, so perhaps that
would require some C level changes so perhaps we don't want to go to
those lengths.  And if really want to dive in the deep end, I'd also
throw in some padding and rounded corners...)