Nastavení skrývání bloků přes „selective-display“.

;; ~/.emacs excerpt
;;   Use function keys f9 through f12 as a 'zoom' control.
(defun zoom-way-out() (interactive)
   (set-selective-display 0))
(defun zoom-way-in() (interactive)
   (set-selective-display 2))
(defun zoom-out() (interactive)
   (set-selective-display
      (if selective-display
         (if (or (= selective-display 0) (= selective-display 10))
         0
      (+ selective-display 2))
      0)))
(defun zoom-in() (interactive)
   (set-selective-display
      (if selective-display
         (if (= selective-display 0)
            10
            (if (= selective-display 2)
               2
               (- selective-display 2)))
         10)))

(global-set-key [f9] 'zoom-way-out)
(global-set-key [f10] 'zoom-out)
(global-set-key [f11] 'zoom-in)
(global-set-key [f12] 'zoom-way-in)