Mercurial > hg > xemacs-beta

comparison lisp/gnus/gnus-undo.el @ 16:0293115a14e9 r19-15b91

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Import from CVS: tag r19-15b91
author cvs
date Mon, 13 Aug 2007 08:49:20 +0200
parents
children 8fc7fe29b841
comparison
equal deleted inserted replaced
15:ad457d5f7d04 16:0293115a14e9
1 ;;; gnus-undo.el --- minor mode for undoing in Gnus
2 ;; Copyright (C) 1996,97 Free Software Foundation, Inc.
3
4 ;; Author: Lars Magne Ingebrigtsen <larsi@ifi.uio.no>
5 ;; Keywords: news
6
7 ;; This file is part of GNU Emacs.
8
9 ;; GNU Emacs is free software; you can redistribute it and/or modify
10 ;; it under the terms of the GNU General Public License as published by
11 ;; the Free Software Foundation; either version 2, or (at your option)
12 ;; any later version.
13
14 ;; GNU Emacs is distributed in the hope that it will be useful,
15 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
16 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 ;; GNU General Public License for more details.
18
19 ;; You should have received a copy of the GNU General Public License
20 ;; along with GNU Emacs; see the file COPYING. If not, write to the
21 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
22 ;; Boston, MA 02111-1307, USA.
23
24 ;;; Commentary:
25
26 ;; This package allows arbitrary undoing in Gnus buffers. As all the
27 ;; Gnus buffers aren't very text-oriented (what is in the buffers is
28 ;; just some random representation of the actual data), normal Emacs
29 ;; undoing doesn't work at all for Gnus.
30 ;;
31 ;; This package works by letting Gnus register functions for reversing
32 ;; actions, and then calling these functions when the user pushes the
33 ;; `undo' key. As with normal `undo', there it is possible to set
34 ;; undo boundaries and so on.
35 ;;
36 ;; Internally, the undo sequence is represented by the
37 ;; `gnus-undo-actions' list, where each element is a list of functions
38 ;; to be called, in sequence, to undo some action. (An "action" is a
39 ;; collection of functions.)
40 ;;
41 ;; For instance, a function for killing a group will call
42 ;; `gnus-undo-register' with a function that un-kills the group. This
43 ;; package will put that function into an action.
44
45 ;;; Code:
46
47 (require 'gnus-util)
48 (require 'gnus)
49
50 (defvar gnus-undo-mode nil
51 "Minor mode for undoing in Gnus buffers.")
52
53 (defvar gnus-undo-mode-hook nil
54 "Hook called in all `gnus-undo-mode' buffers.")
55
56 ;;; Internal variables.
57
58 (defvar gnus-undo-actions nil)
59 (defvar gnus-undo-boundary t)
60 (defvar gnus-undo-last nil)
61 (defvar gnus-undo-boundary-inhibit nil)
62
63 ;;; Minor mode definition.
64
65 (defvar gnus-undo-mode-map nil)
66
67 (unless gnus-undo-mode-map
68 (setq gnus-undo-mode-map (make-sparse-keymap))
69
70 (gnus-define-keys gnus-undo-mode-map
71 "\M-\C-_" gnus-undo))
72
73 (defun gnus-undo-make-menu-bar ()
74 (when nil
75 (define-key-after (current-local-map) [menu-bar file gnus-undo]
76 (cons "Undo" 'gnus-undo-actions)
77 [menu-bar file whatever])))
78
79 (defun gnus-undo-mode (&optional arg)
80 "Minor mode for providing `undo' in Gnus buffers.
81
82 \\{gnus-undo-mode-map}"
83 (interactive "P")
84 (set (make-local-variable 'gnus-undo-mode)
85 (if (null arg) (not gnus-undo-mode)
86 (> (prefix-numeric-value arg) 0)))
87 (set (make-local-variable 'gnus-undo-actions) nil)
88 (set (make-local-variable 'gnus-undo-boundary) t)
89 (when gnus-undo-mode
90 ;; Set up the menu.
91 (when (gnus-visual-p 'undo-menu 'menu)
92 (gnus-undo-make-menu-bar))
93 ;; Don't display anything in the mode line -- too annoying.
94 ;;(unless (assq 'gnus-undo-mode minor-mode-alist)
95 ;; (push '(gnus-undo-mode " Undo") minor-mode-alist))
96 (unless (assq 'gnus-undo-mode minor-mode-map-alist)
97 (push (cons 'gnus-undo-mode gnus-undo-mode-map)
98 minor-mode-map-alist))
99 (gnus-make-local-hook 'post-command-hook)
100 (gnus-add-hook 'post-command-hook 'gnus-undo-boundary nil t)
101 (add-hook 'gnus-summary-exit-hook 'gnus-undo-boundary)
102 (run-hooks 'gnus-undo-mode-hook)))
103
104 ;;; Interface functions.
105
106 (defun gnus-disable-undo (&optional buffer)
107 "Disable undoing in the current buffer."
108 (interactive)
109 (save-excursion
110 (when buffer
111 (set-buffer buffer))
112 (gnus-undo-mode -1)))
113
114 (defun gnus-undo-boundary ()
115 "Set Gnus undo boundary."
116 (if gnus-undo-boundary-inhibit
117 (setq gnus-undo-boundary-inhibit nil)
118 (setq gnus-undo-boundary t)))
119
120 (defun gnus-undo-register (form)
121 "Register FORMS as something to be performed to undo a change.
122 FORMS may use backtick quote syntax."
123 (when gnus-undo-mode
124 (gnus-undo-register-1
125 `(lambda ()
126 ,form))))
127
128 (put 'gnus-undo-register 'lisp-indent-function 0)
129 (put 'gnus-undo-register 'edebug-form-spec '(body))
130
131 (defun gnus-undo-register-1 (function)
132 "Register FUNCTION as something to be performed to undo a change."
133 (when gnus-undo-mode
134 (cond
135 ;; We are on a boundary, so we create a new action.
136 (gnus-undo-boundary
137 (push (list function) gnus-undo-actions)
138 (setq gnus-undo-boundary nil))
139 ;; Prepend the function to an old action.
140 (gnus-undo-actions
141 (setcar gnus-undo-actions (cons function (car gnus-undo-actions))))
142 ;; Initialize list.
143 (t
144 (setq gnus-undo-actions (list (list function)))))
145 (setq gnus-undo-boundary-inhibit t)))
146
147 (defun gnus-undo (n)
148 "Undo some previous changes in Gnus buffers.
149 Repeat this command to undo more changes.
150 A numeric argument serves as a repeat count."
151 (interactive "p")
152 (unless gnus-undo-mode
153 (error "Undoing is not enabled in this buffer"))
154 (message "%s" last-command)
155 (when (or (not (eq last-command 'gnus-undo))
156 (not gnus-undo-last))
157 (setq gnus-undo-last gnus-undo-actions))
158 (let ((action (pop gnus-undo-last)))
159 (unless action
160 (error "Nothing further to undo"))
161 (setq gnus-undo-actions (delq action gnus-undo-actions))
162 (setq gnus-undo-boundary t)
163 (while action
164 (funcall (pop action)))))
165
166 (provide 'gnus-undo)
167
168 ;;; gnus-undo.el ends here