Thank you very much! It was a bit surprising to learn that appearance of
the tab-bar is controller by the keymap ;)
I was using `header-line` as a panel with EXWM, but it didn't work well
with modes like info which define their own header-line.
Now it's much better!

On Thu, Oct 17, 2019 at 12:15 AM Juri Linkov <juri@linkov.net> wrote:

> > Is it possible to change how tab-bar is formatted?
> > For example I'd like to put display-time-string there.
>
> Yes, everything is possible.  You need just a few lines of code:
>
> (advice-add 'tab-bar-make-keymap-1 :around
>   (lambda (orig-fun)
>     (append `(keymap (display-time menu-item ,(format-time-string "%H:%M")
> ignore))
>             (cdr (funcall orig-fun))))
>   '((name . tab-bar-display-time)))
>
> and if you want also a timer to redraw the tab-bar during idle times.
>
> This has one problem - the clock is located on the left side.  When
> Android moved the status bar clock from the right corner to the left,
> it caused backward-compatibility problems for millions of users, and
> still it's impossible to move the clock back to the right on Android.
>
> But in Emacs everything is extensible and customizable.  So it's easy
> to move the clock to the right on the tab-bar with another few lines:
>
> (advice-add 'tab-bar-make-keymap-1 :around
>   (lambda (orig-fun)
>     (append (funcall orig-fun)
>             `((display-time menu-item
>                ,(concat
>                  (propertize " " 'display '(space :align-to (- right 5)))
>                  (format-time-string "%H:%M"))
>                ignore))))
>   '((name . tab-bar-display-time)))
>
> Now the tab-bar clock looks exactly like the desktop top panel clock:
>
>