Presentations in Org-Mode

I recently came up with my own take on doing presentations using org-mode. There are probably far better approaches and feature-rich packages out there, but at this point it's all about fun. The fw/org-present-mode minor mode narrows down an org document to the current subtree when pressing F5. Afterwards you can use the left/right arrow keys to jump to the next/previous subtree at the same level. Pressing F5 a second time quits the minor mode.

(define-minor-mode fw/org-present-mode
  "Do a presentation based on an org-mode file."
  :lighter " fw/org-present"
  :keymap (let ((map (make-sparse-keymap)))
            (define-key map (kbd "<left>") 'fw/org-present-backward)
            (define-key map (kbd "<right>") 'fw/org-present-forward)
            map)

  (defun fw/org-present-backward ()
    (interactive)
    (let ((inhibit-message t))
      (widen)
      (org-backward-heading-same-level 1)
      (org-toggle-narrow-to-subtree)))

  (defun fw/org-present-forward ()
    (interactive)
    (let ((inhibit-message t))
      (widen)
      (org-forward-heading-same-level 1)
      (org-toggle-narrow-to-subtree)))

  (toggle-frame-fullscreen)

  (if (buffer-narrowed-p)
      (progn
        (kill-local-variable 'mode-line-format)
        (read-only-mode -1)
        (widen))
    (progn
      (setq-local mode-line-format nil)
      (org-toggle-narrow-to-subtree)
      (read-only-mode 1))))

(bind-keys ("<f5>" . fw/org-present-mode))