;;; gnus-undo.el --- minor mode for undoing in Gnus
-;; Copyright (C) 1996 Free Software Foundation, Inc.
-;; Author: Lars Magne Ingebrigtsen <larsi@ifi.uio.no>
+;; Copyright (C) 1996-2013 Free Software Foundation, Inc.
+
+;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
;; Keywords: news
;; This file is part of GNU Emacs.
-;; GNU Emacs is free software; you can redistribute it and/or modify
+;; GNU Emacs 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.
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
;; GNU Emacs 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
+;; 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., 59 Temple Place - Suite 330,
-;; Boston, MA 02111-1307, USA.
+;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
;;; Commentary:
;; This package allows arbitrary undoing in Gnus buffers. As all the
;; Gnus buffers aren't very text-oriented (what is in the buffers is
-;; just some random representation of the actual data), normal Emacs
+;; just some arbitrary representation of the actual data), normal Emacs
;; undoing doesn't work at all for Gnus.
;;
;; This package works by letting Gnus register functions for reversing
;;; Code:
+(eval-when-compile (require 'cl))
+(eval-when-compile
+ (when (featurep 'xemacs)
+ (require 'easy-mmode))) ; for `define-minor-mode'
+
(require 'gnus-util)
(require 'gnus)
-(defvar gnus-undo-mode nil
- "Minor mode for undoing in Gnus buffers.")
-
-(defvar gnus-undo-mode-hook nil
- "Hook called in all `gnus-undo-mode' buffers.")
+(defgroup gnus-undo nil
+ "Undoing in Gnus buffers."
+ :group 'gnus)
+
+(defcustom gnus-undo-limit 2000
+ "The number of undoable actions recorded."
+ :type 'integer
+ :group 'gnus-undo)
+
+(defcustom gnus-undo-mode nil
+ ;; FIXME: This is a buffer-local minor mode which requires running
+ ;; code upon activation/deactivation, so defining it as a defcustom
+ ;; doesn't seem very useful: setting it to non-nil via Customize
+ ;; probably won't do the right thing.
+ "Minor mode for undoing in Gnus buffers."
+ :type 'boolean
+ :group 'gnus-undo)
+
+(defcustom gnus-undo-mode-hook nil
+ "Hook called in all `gnus-undo-mode' buffers."
+ :type 'hook
+ :group 'gnus-undo)
;;; Internal variables.
;;; Minor mode definition.
-(defvar gnus-undo-mode-map nil)
-
-(unless gnus-undo-mode-map
- (setq gnus-undo-mode-map (make-sparse-keymap))
-
- (gnus-define-keys gnus-undo-mode-map
- "\M-\C-_" gnus-undo))
+(defvar gnus-undo-mode-map
+ (let ((map (make-sparse-keymap)))
+ (gnus-define-keys map
+ "\M-\C-_" gnus-undo
+ "\C-_" gnus-undo
+ "\C-xu" gnus-undo
+ ;; many people are used to type `C-/' on X terminals and get `C-_'.
+ [(control /)] gnus-undo)
+ map))
(defun gnus-undo-make-menu-bar ()
+ ;; This is disabled for the time being.
(when nil
- (define-key-after (current-local-map) [menu-bar file gnus-undo]
- (cons "Undo" 'gnus-undo-actions)
- [menu-bar file whatever])))
+ (define-key-after (current-local-map) [menu-bar file gnus-undo]
+ (cons "Undo" 'gnus-undo-actions)
+ [menu-bar file whatever])))
-(defun gnus-undo-mode (&optional arg)
+(define-minor-mode gnus-undo-mode
"Minor mode for providing `undo' in Gnus buffers.
\\{gnus-undo-mode-map}"
- (interactive "P")
- (set (make-local-variable 'gnus-undo-mode)
- (if (null arg) (not gnus-undo-mode)
- (> (prefix-numeric-value arg) 0)))
+ :keymap gnus-undo-mode-map
(set (make-local-variable 'gnus-undo-actions) nil)
(set (make-local-variable 'gnus-undo-boundary) t)
(when gnus-undo-mode
;; Set up the menu.
(when (gnus-visual-p 'undo-menu 'menu)
(gnus-undo-make-menu-bar))
- ;; Don't display anything in the mode line -- too annoying.
- ;;(unless (assq 'gnus-undo-mode minor-mode-alist)
- ;; (push '(gnus-undo-mode " Undo") minor-mode-alist))
- (unless (assq 'gnus-undo-mode minor-mode-map-alist)
- (push (cons 'gnus-undo-mode gnus-undo-mode-map)
- minor-mode-map-alist))
(gnus-make-local-hook 'post-command-hook)
- (gnus-add-hook 'post-command-hook 'gnus-undo-boundary nil t)
- (run-hooks 'gnus-undo-mode-hook)))
+ (add-hook 'post-command-hook 'gnus-undo-boundary nil t)))
;;; Interface functions.
(setq gnus-undo-boundary-inhibit nil)
(setq gnus-undo-boundary t)))
+(defun gnus-undo-force-boundary ()
+ "Set Gnus undo boundary."
+ (setq gnus-undo-boundary-inhibit nil
+ gnus-undo-boundary t))
+
(defun gnus-undo-register (form)
"Register FORMS as something to be performed to undo a change.
FORMS may use backtick quote syntax."
;; Initialize list.
(t
(setq gnus-undo-actions (list (list function)))))
+ ;; Limit the length of the undo list.
+ (let ((next (nthcdr gnus-undo-limit gnus-undo-actions)))
+ (when next
+ (setcdr next nil)))
+ ;; We are not at a boundary...
(setq gnus-undo-boundary-inhibit t)))
(defun gnus-undo (n)
(error "Nothing further to undo"))
(setq gnus-undo-actions (delq action gnus-undo-actions))
(setq gnus-undo-boundary t)
- (while action
- (funcall (pop action)))))
+ (mapc 'funcall action)))
(provide 'gnus-undo)