With the help of @Drew, I figure out a solution. I am not good at elisp. The code may not be a good design but at least is working. I use this code to add 4 white space so I can copy a highlighted code and paste to web like stackoverflow and remove 4 white space afterward easily.
(defun shift-region (distance) (let ((beg (save-excursion (goto-char (region-beginning))(line-beginning-position))) (end (save-excursion (goto-char (region-end))(line-end-position)))) (goto-char beg) (set-mark end) (indent-rigidly beg end distance) (setq deactivate-mark nil))) (defun shift-right () (interactive) (shift-region 4)) (defun shift-left () (interactive) (shift-region -4)) (global-set-key (kbd "C-<tab>") 'shift-right) (global-set-key (kbd "<backtab>") 'shift-left)
I have this code
(defun shift-region (distance) (let ((mark (mark))) (save-excursion (indent-rigidly (region-beginning) (region-end) distance) (push-mark mark t t) (setq deactivate-mark nil))))
I want to expand the
region-beginning to the beginning of that line
region-end to the end of that line.
Visual representation (I use [ ] to represent the region mark)
abcde abcde [ fghi abcdefghi abc ] defg abcde
abcde [ abcdefghi abcdefghi abcdefg ] abcde