Variable: tab-bar-tab-group-format-function
tab-bar-tab-group-format-function is a customizable variable defined
in tab-bar.el.gz.
Value
tab-bar-tab-group-format-default
Documentation
Function to format a tab group name.
Function gets two arguments, a tab with a group name and its number, and should return the formatted tab group name to display in the tab bar.
This variable was added, or its default value changed, in Emacs 28.1.
Source Code
;; Defined in /usr/src/emacs/lisp/tab-bar.el.gz
(defcustom tab-bar-tab-group-format-function #'tab-bar-tab-group-format-default
"Function to format a tab group name.
Function gets two arguments, a tab with a group name and its number,
and should return the formatted tab group name to display in the tab bar."
:type 'function
:initialize 'custom-initialize-default
:set (lambda (sym val)
(set-default sym val)
(force-mode-line-update))
:group 'tab-bar
:version "28.1")