;;; comment-uncomment-line-or-region.el --- comments or
;;; uncomments current line or region according to
;;; state before.

;; Version: 1.0

;; Copyright (C) 2006 Andreas Roehler

;; Author: Andreas Roehler
;; Keywords: comment uncomment

;; This file is free software; you can redistribute it
;; and/or modify it under the terms of the GNU General Public License
;; as published by the Free Software Foundation; either version 2,
;; or (at your option) any later version.

;; This file is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING. If not, write to
;; the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, USA.

;;; Commentary:

;; Tries to be a quick commenting/uncommenting
;; facility, as it respects region - active-mark and
;; transient-mark-mode - but doesn't depend on them. If
;; on a line, wanting to comment or uncomment them,
;; you don't have to care if transient-mark-mode is on.

;; Should you intend to comment/uncomment more lines,
;; it also works that way: just keep the key pressed.

;; The region is respected and worked on nonetheless if
;; transient-mark-mode is active

;; Given a numeric arg of 1 it copies line or region
;; first, so you get the text commented and uncommented
;; likewise

;;; Code:

;; (global-set-key (kbd "") 'comment-uncomment-line-or-region)

(defun comment-uncomment-line-or-region (&optional arg)
"comments or uncomments a line according to state before.
With key pressed, continues with next line.
With arg copies and reinserts last line."
(interactive "*P")
(comment-normalize-vars)
(let* ((arg (if arg (prefix-numeric-value arg) 0))
(start (if (and mark-active transient-mark-mode)
(region-beginning)
(line-beginning-position)))
(end (if (and mark-active transient-mark-mode)
(region-end)
(line-end-position)))
(line-to-comment-or-uncomment (buffer-substring-no-properties
(or
start (line-beginning-position))
(or end
(line-end-position)))))
(cond ((eq 1 arg) ;; comment and reinsert
(comment-or-uncomment-region start end)
(indent-according-to-mode)
(end-of-line)
(newline)
(insert line-to-comment-or-uncomment)
(indent-according-to-mode))
((< 1 arg) ;; comment as many lines are given
(while (<= 1 (prefix-numeric-value arg))
(comment-or-uncomment-region (line-beginning-position) (line-end-position))
(indent-according-to-mode)
(end-of-line)
(forward-line 1)
;; (indent-according-to-mode)
(setq arg (1- arg))))
((and start end)
(comment-or-uncomment-region start end)
(indent-according-to-mode)
(if (eobp)
(progn (newline)
(indent-according-to-mode))
(progn
(forward-line 1)
(indent-according-to-mode))))
(t ;; just one line
(progn (comment-or-uncomment-region (line-beginning-position) (line-end-position))
(indent-according-to-mode)
(if (eobp)
(progn (newline)
(indent-according-to-mode))
(progn
(forward-line 1)
(indent-according-to-mode))))))))

(provide 'comment-uncomment-line-or-region)
;;; comment-uncomment-line-or-region.el ends here