Variable: activate-mark-hook
activate-mark-hook is a variable defined in simple.el.gz.
Value
(tpu-update-mode-line)
Documentation
Hook run when the mark becomes active.
It is also run when the region is reactivated, for instance after using a command that switches back to a buffer that has an active mark.
Source Code
;; Defined in /usr/src/emacs/lisp/simple.el.gz
(defvar activate-mark-hook nil
"Hook run when the mark becomes active.
It is also run when the region is reactivated, for instance after
using a command that switches back to a buffer that has an active
mark.")