bug#39979: 28.0.50; `mouse-wheel-tilt-scroll' docstring is unclear/incomplete

[Göktuğ Kayaalp]

On 2020-03-09 10:02 +01, martin rudalics <rudalics@gmx.at> wrote:
>  > A patch is attached which is proposed as a tentative improvement. If
>  > it’s good enough to apply, I do have my copyright assingment paperwork
>  > done so it can be committed right away.
>
> Thanks for looking into this.  But
>
> -  "Enable scroll using tilting mouse wheel."
> +  "Enable horizontal scrolling via mouse or touchpad. Also see
> +  ‘mouse-wheel-flip-direction’."
>
> violates the rule from D.6 of the Elisp manual:
>
>   The first line of the documentation string should consist of one or
>       two complete sentences that stand on their own as a summary.

New patch added, with some improvement to the ‘...-flip-direction’
variable too.

> Also, 'mouse-wheel-flip-direction' does not have a great doc-string
> either.  Maybe we should add a reference to section 21.1 of the Emacs
> manual?

There is this, assuming you meant "(emacs) Mouse Commands":

,----
|    Emacs can also support horizontal scrolling if your mouse’s wheel can
| be tilted.  This feature is off by default; the variable
| ‘mouse-wheel-tilt-scroll’ turns it on.  If you’d like to reverse the
| direction of horizontal scrolling, customize the variable
| ‘mouse-wheel-flip-direction’ to a non-‘nil’ value.
`----

I think a little mention of touchpads would suffice.  The added patch
addresses this too.

Cheers,

        -gk.

P.S. I never know if it’s better to send Debbugs patches inline or as
attachments.  Sorry if I’m doing the wrong thing.

0001-Improve-docs-for-horizontal-scrolling-with-mouse-and.patch
Description: Improved patch