;;; destroy-trailing-whitespace.el --- Destroy all trailing whitespace  -*- lexical-binding: t; -*-

;; Copyright (C) 2016  Tom Willemse

;; Author: Tom Willemse <chelys@drd>
;; Keywords: convenience

;; This program 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 3 of the License, or
;; (at your option) any later version.

;; This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.

;;; Commentary:

;; This library offers a single mode that will delete all trailing
;; whitespace before saving any file. It tries to be intelligent
;; enough to only do this for modes where trailing whitespace is not
;; meaningful. Currently it only keeps whitespace around in
;; `markdown-mode' since it uses two spaces at the end of a line to
;; signify a line break.
;;
;; To use this mode in all buffers, add the following to your init
;; file:
;;
;;    (require 'destroy-trailing-whitespace)
;;    (global-destroy-trailing-whitespace-mode)
;;
;; To use this mode in just some buffers add it to your preferred
;; hook. For example, to use it only in `prog-mode' buffers:
;;
;;    (require 'destroy-trailing-whitespace)
;;    (add-hook 'prog-mode-hook 'destroy-trailing-whitespace-mode)

;;; Code:

(defun destroy-trailing-whitespace ()
  "Delete trailing whitespace everywhere, except in Markdown buffers."
  (if (not (eq major-mode 'markdown-mode))
      (delete-trailing-whitespace)))

;;;###autoload
(define-minor-mode destroy-trailing-whitespace-mode
  "Destroy all trailing whitespace before saving the buffer."
  :lighter ""
  (if destroy-trailing-whitespace-mode
      (add-hook 'before-save-hook 'delete-trailing-whitespace nil :local)
    (remove-hook 'before-save-hook 'delete-trailing-whitespace :local)))

;;;###autoload
(define-minor-mode global-destroy-trailing-whitespace-mode
  "Destroy all trailing whitespace before saving any open buffer."
  :lighter "" :global t
  (if global-destroy-trailing-whitespace-mode
      (add-hook 'before-save-hook 'destroy-trailing-whitespace)
    (remove-hook 'before-save-hook 'destroy-trailing-whitespace)))

(provide 'destroy-trailing-whitespace)
;;; destroy-trailing-whitespace.el ends here