+++ /dev/null
-;;; gnus-undo.el --- minor mode for undoing in Gnus
-
-;; Copyright (C) 1996, 1997, 1998, 1999, 2000
-;; 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
-;; 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)
-
-;;; gnus-undo.el ends here
projects / elisp / gnus.git- / blobdiff