(defun english-reading ()
  (interactive)
  (let ((bname (format "*ER:%s*" (buffer-name)))
        (pt (point))
        (ws (window-start))
        (mode major-mode)
        (cb (current-buffer)))
    (switch-to-buffer (generate-new-buffer bname))
    (funcall mode)
    (setq-local inhibit-read-only t)
    (insert-buffer-substring-no-properties cb)
    (goto-char pt)
    (set-window-start (selected-window) ws)
    ;; uncomment-region-function in org-mode is org-comment-or-uncomment-region
    ;; so, uncomment-region COMMENTS whole buffer.
    (when (and comment-start
               (not (memq major-mode '(org-mode))))
      (uncomment-region (point-min) (point-max)))
    (english-reading-mode)))

(defun english-reading-mouse-open-line (event)
  (interactive "e")
  (posn-set-point (event-end event))
  (unless (eq ?\  (char-syntax (char-after)))
    (forward-word 1))
  (open-line 1))

(defun english-reading-mouse-highlight-current-word (e)
  (interactive "e")
  (mouse-set-point e)
  (let ((bow (bounds-of-thing-at-point 'word)))
    (overlay-put (make-overlay (car bow) (cdr bow))
                 'face 'highlight)))

(defun english-reading-mouse-delete-indentation (event)
  (interactive "e")
  (posn-set-point (event-end event))
  (delete-indentation)
  (when (and (not (< 0 (char-before) 127 ))
             (eq (char-after) ?\s))
    (delete-char 1)))

(define-derived-mode english-reading-mode text-mode "ER"
  (when (bound-and-true-p mouse-click-scroll-mode)
    (setq-local mouse-click-scroll-mode nil))
  (setq-local mouse-wheel-scroll-amount '(3))    ; HERE!
  (face-remap-add-relative 'default :height 300) ; HERE!
  (define-key english-reading-mode-map (kbd "<down-mouse-1>") 'ignore)
  (define-key english-reading-mode-map (kbd "<down-mouse-2>") 'ignore)
  (define-key english-reading-mode-map (kbd "<down-mouse-3>") 'ignore)
  (define-key english-reading-mode-map (kbd "<mouse-1>") 'english-reading-mouse-open-line)
  (define-key english-reading-mode-map (kbd "<mouse-2>") 'english-reading-mouse-highlight-current-word)
  (define-key english-reading-mode-map (kbd "<mouse-3>") 'english-reading-mouse-delete-indentation))

(provide 'mylisp-english-reading)