[Emacs-diffs] Changes to emacs/lisp/gnus/gnus-undo.el [lexbind]

[Miles Bader]

Index: emacs/lisp/gnus/gnus-undo.el
diff -c /dev/null emacs/lisp/gnus/gnus-undo.el:1.5.18.1
*** /dev/null   Tue Oct 14 19:34:56 2003
--- emacs/lisp/gnus/gnus-undo.el        Tue Oct 14 19:34:50 2003
***************
*** 0 ****
--- 1,196 ----
+ ;;; gnus-undo.el --- minor mode for undoing in Gnus
+ 
+ ;; Copyright (C) 1996, 1997, 1998, 1999, 2000
+ ;;    Free Software Foundation, Inc.
+ 
+ ;; Author: Lars Magne Ingebrigtsen <address@hidden>
+ ;; Keywords: news
+ 
+ ;; This file is part of GNU Emacs.
+ 
+ ;; 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.
+ 
+ ;; 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
+ ;; 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.
+ 
+ ;;; 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 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
+ ;; actions, and then calling these functions when the user pushes the
+ ;; `undo' key.  As with normal `undo', there it is possible to set
+ ;; undo boundaries and so on.
+ ;;
+ ;; Internally, the undo sequence is represented by the
+ ;; `gnus-undo-actions' list, where each element is a list of functions
+ ;; to be called, in sequence, to undo some action.  (An "action" is a
+ ;; collection of functions.)
+ ;;
+ ;; For instance, a function for killing a group will call
+ ;; `gnus-undo-register' with a function that un-kills the group.  This
+ ;; package will put that function into an action.
+ 
+ ;;; Code:
+ 
+ (eval-when-compile (require 'cl))
+ 
+ (require 'gnus-util)
+ (require 'gnus)
+ (require 'custom)
+ 
+ (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
+   "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.
+ 
+ (defvar gnus-undo-actions nil)
+ (defvar gnus-undo-boundary t)
+ (defvar gnus-undo-last nil)
+ (defvar gnus-undo-boundary-inhibit nil)
+ 
+ ;;; 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
+     "\C-_"        gnus-undo
+     "\C-xu"       gnus-undo
+     ;; many people are used to type `C-/' on X terminals and get `C-_'.
+     [(control /)] gnus-undo))
+ 
+ (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])))
+ 
+ (defun gnus-undo-mode (&optional arg)
+   "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)))
+   (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))
+     (gnus-add-minor-mode 'gnus-undo-mode "" gnus-undo-mode-map)
+     (make-local-hook 'post-command-hook)
+     (add-hook 'post-command-hook 'gnus-undo-boundary nil t)
+     (gnus-run-hooks 'gnus-undo-mode-hook)))
+ 
+ ;;; Interface functions.
+ 
+ (defun gnus-disable-undo (&optional buffer)
+   "Disable undoing in the current buffer."
+   (interactive)
+   (save-excursion
+     (when buffer
+       (set-buffer buffer))
+     (gnus-undo-mode -1)))
+ 
+ (defun gnus-undo-boundary ()
+   "Set Gnus undo boundary."
+   (if gnus-undo-boundary-inhibit
+       (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."
+   (when gnus-undo-mode
+     (gnus-undo-register-1
+      `(lambda ()
+       ,form))))
+ 
+ (put 'gnus-undo-register 'lisp-indent-function 0)
+ (put 'gnus-undo-register 'edebug-form-spec '(body))
+ 
+ (defun gnus-undo-register-1 (function)
+   "Register FUNCTION as something to be performed to undo a change."
+   (when gnus-undo-mode
+     (cond
+      ;; We are on a boundary, so we create a new action.
+      (gnus-undo-boundary
+       (push (list function) gnus-undo-actions)
+       (setq gnus-undo-boundary nil))
+      ;; Prepend the function to an old action.
+      (gnus-undo-actions
+       (setcar gnus-undo-actions (cons function (car gnus-undo-actions))))
+      ;; 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)
+   "Undo some previous changes in Gnus buffers.
+ Repeat this command to undo more changes.
+ A numeric argument serves as a repeat count."
+   (interactive "p")
+   (unless gnus-undo-mode
+     (error "Undoing is not enabled in this buffer"))
+   (message "%s" last-command)
+   (when (or (not (eq last-command 'gnus-undo))
+           (not gnus-undo-last))
+     (setq gnus-undo-last gnus-undo-actions))
+   (let ((action (pop gnus-undo-last)))
+     (unless action
+       (error "Nothing further to undo"))
+     (setq gnus-undo-actions (delq action gnus-undo-actions))
+     (setq gnus-undo-boundary t)
+     (while action
+       (funcall (pop action)))))
+ 
+ (provide 'gnus-undo)
+ 
+ ;;; arch-tag: 0d787bc7-787d-499a-837f-211d2cb07f2e
+ ;;; gnus-undo.el ends here