highlight extent

gistfile1.txt

;;;###autoload
(defun ispell-hl-minor-mode (&optional arg)
  "Toggle Ispell Highlight mode.
With prefix ARG, turn Ispell Highlight mode on if arg is positive.
 
In Ispell Highlight mode, changing the buffer contens will spell
the words around the cursor and highlight miss-spelled ones!"
  (interactive "P")
  (setq ispell-hl-minor-mode
        (not (or (and (null arg) ispell-hl-minor-mode)
                 (<= (prefix-numeric-value arg) 0))))
  
  (make-local-hook 'before-change-functions)
  (make-local-hook 'after-change-functions)

  (if ispell-hl-minor-mode
      (progn
        (add-hook 'before-change-functions 'ispell-hl-before-check-word nil t)
        (add-hook 'after-change-functions 'ispell-hl-check-word nil t)
        )
    (progn
      (remove-hook 'before-change-functions 'ispell-hl-before-check-word t)
      (remove-hook 'after-change-functions 'ispell-hl-check-word t)
      (ispell-hl-buffer t)              ; remove highlighted errors
      ))
  
  (redraw-modeline))

(make-face 'ispell-hl-error-face
           "Face to use for highlighting spelling errors.")

(set-face-foreground    'ispell-hl-error-face "red3")
(set-face-underline-p   'ispell-hl-error-face t)

(defun ispell-hl-error (from to)
  "Highlight the region delimited by FROM and TO as a spelling-error."
  (interactive "r")
  (let ((x (make-extent from to (current-buffer))))
    (set-extent-keymap x ispell-hl-keymap)
    (set-extent-property x 'pointer selection-pointer-glyph)
    (set-extent-property x 'duplicable t)
    (set-extent-property x 'unique t)
    (set-extent-property x 'start-open t)
    (set-extent-property x 'end-closed t)
    (set-extent-priority x 1000)
    (set-extent-property x 'ispell-hl-error t)
    (set-extent-face x 'ispell-hl-error-face)))