Hi Eli,

attached is a small patch with a proof of concept for the master branch
ONLY TESTED ON LINUX.

With this I can define my tab-line as

'(tab-line ((t (:inherit fringe :box (:line-width (5 . 5) :style
modern-button))))))

And changes in the fringe are taken *automatically* by the tabline.

Best, /Pedro A. Aranda

On Tue, 8 Dec 2020 at 18:09, Pedro Andres Aranda Gutierrez <
paaguti@gmail.com> wrote:

> Hi Eli,
>
> let's see if a couple of lines of code explain more than a thousand lines
> of 'literature'
>
> I use :box to make some parts of the GUI bigger than one display line.
> For example my mode-line face is
>
> '(mode-line ((t (:background "#4C566A" :foreground "#88C0D0" :weight bold
> :box (:line-width 6 :color "#4C566A")))))
>
> and yes, OK, at the beginning, I could accept to repeat the background
> definition inside the :box, however inconvenient it may be.
>
> Now, I have some some situations where I want to have a common look and
> feel:
>
>     '(fringe ((,class (:foreground "#007fcf" :background "#afaf9f"))))
>     '(line-number ((,class (:inherit fringe))))
>
> But when I want an element to be higher that the normal size, I need to
> repeat the background definition in the :box
>       `(tab-line ((,class (:inherit fringe :box (:line-width 3 :color
> "#afaf9f")))))
>
> Which means that when I change the fringe background, I need to change it
> both in fringe and in tab-line to keep everything uniform.
> You pointed out :style t but that uses the _fore_ground for the box,
> whereas I need the _back_ground (same happens with :style nil)
>
> This is why I was proposing a new :style modern that fills the box with
> the background color of the face. How feasible would be my proposal?
>
> Best, /PA
>
> On Tue, 8 Dec 2020 at 16:16, Eli Zaretskii <eliz@gnu.org> wrote:
>
>> > From: Pedro Andres Aranda Gutierrez <paaguti@gmail.com>
>> > Date: Tue, 8 Dec 2020 07:21:42 +0100
>> > Cc: emacs-devel@gnu.org
>> >
>> > unfortunately not. :style nil takes the _fore_ground for the box and
>> I'm looking for the _back_ground
>> >
>> > :style nil
>> > Screenshot-20201208071520-101x110.png
>> >
>> > what I want
>> > Screenshot-20201208071702-126x105.png
>>
>> I'm confused: I thought you wanted to get rid of the 3D appearance,
>> which is why I suggested to use :style.  But now you seem to be
>> talking about the colors, and I cannot understand what exactly is the
>> problem with that -- just change the colors to whatever you want.
>>
>> > In a general case, if you are deriving from another face, you have to
>> write the background colour twice: in the
>> > face you are deriving from and in the face :inheri ing the definition.
>> This, any change in the parent face
>> > implies a change in the derived face and that's not exactly
>> convenient...
>>
>> If the inheriting face overrides the color of the parent face, there's
>> no need to change the former when the latter changes.  So here, too, I
>> don't think I follow you, please elaborate.
>>
>
>
> --
> Fragen sind nicht da um beantwortet zu werden,
> Fragen sind da um gestellt zu werden
> Georg Kreisler
>


-- 
Fragen sind nicht da um beantwortet zu werden,
Fragen sind da um gestellt zu werden
Georg Kreisler