Emacs - Always highlight matching parent (use echo area if out of screen)

paren.el

(defun my-show-paren-for-line-start ()
  (interactive)
  (add-hook 'post-command-hook 'my-show-paren-for-line-setup-overlay t t))


(defun my-show-paren-for-line-stop ()
  (interactive)
  (remove-hook 'post-command-hook 'my-show-paren-for-line-setup-overlay t))


(setq my-show-paren-for-line-overlay  (make-overlay (point) (point)))
(overlay-put my-show-paren-for-line-overlay
             'face '(background-color . "cyan"))
(delete-overlay my-show-paren-for-line-overlay) ;; hide it

(defun my-show-paren-for-line-setup-overlay ()
  (if (and (looking-at ".*))\\s-*$")
           (not (eq (char-before) ?\))))
      (save-excursion
        (ignore-errors
          (end-of-line)
          (backward-sexp)
          (if (< (point) (window-start))
              (message "Matches %s" (buffer-substring (line-beginning-position) (line-end-position)))

            (move-overlay my-show-paren-for-line-overlay (point) (1+ (point)))
            (add-hook 'pre-command-hook 'my-show-paren-for-line-hide-overlay t t))))))


(defun my-show-paren-for-line-hide-overlay ()
  (delete-overlay my-show-paren-for-line-overlay)
  (remove-hook 'pre-command-hook 'my-show-paren-for-line-hide-overlay t))