Commit | Line | Data |
---|---|---|
722074ef RS |
1 | ;;; saveplace.el --- automatically save place in files. |
2 | ||
e7dc77f6 | 3 | ;; Copyright (C) 1993, 1994 Free Software Foundation, Inc. |
722074ef RS |
4 | |
5 | ;; Author: Karl Fogel <kfogel@cs.oberlin.edu> | |
6 | ;; Maintainer: FSF | |
7 | ;; Created: July, 1993 | |
b6ace927 | 8 | ;; Version: 1.2 |
722074ef RS |
9 | ;; Keywords: bookmarks, placeholders |
10 | ||
11 | ;; This file is part of GNU Emacs. | |
12 | ||
13 | ;; GNU Emacs is free software; you can redistribute it and/or modify | |
14 | ;; it under the terms of the GNU General Public License as published by | |
15 | ;; the Free Software Foundation; either version 2, or (at your option) | |
16 | ;; any later version. | |
17 | ||
18 | ;; GNU Emacs is distributed in the hope that it will be useful, | |
19 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
20 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
21 | ;; GNU General Public License for more details. | |
22 | ||
23 | ;; You should have received a copy of the GNU General Public License | |
b578f267 EN |
24 | ;; along with GNU Emacs; see the file COPYING. If not, write to the |
25 | ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
26 | ;; Boston, MA 02111-1307, USA. | |
27 | ||
28 | ;;; Commentary: | |
722074ef RS |
29 | |
30 | ;; Automatically save place in files, so that visiting them later | |
31 | ;; (even during a different Emacs session) automatically moves point | |
32 | ;; to the saved position, when the file is first found. Uses the | |
33 | ;; value of buffer-local variable save-place to determine whether to | |
34 | ;; save position or not. | |
35 | ;; | |
e7dc77f6 RS |
36 | ;; Thanks to Stefan Schoef, who sent a patch with the |
37 | ;; `save-place-version-control' stuff in it. | |
722074ef | 38 | |
b578f267 EN |
39 | ;;; Code: |
40 | ||
722074ef RS |
41 | ;; this is what I was using during testing: |
42 | ;; (define-key ctl-x-map "p" 'toggle-save-place) | |
43 | ||
44 | (defvar save-place-alist nil | |
45 | "Alist of saved places to go back to when revisiting files. | |
46 | Each element looks like (FILENAME . POSITION); | |
47 | visiting file FILENAME goes automatically to position POSITION | |
48 | rather than the beginning of the buffer. | |
49 | This alist is saved between Emacs sessions.") | |
50 | ||
51 | (defvar save-place nil | |
52 | "*Non-nil means automatically save place in each file. | |
53 | This means when you visit a file, point goes to the last place | |
54 | where it was when you previously visited the same file. | |
55 | This variable is automatically buffer-local. | |
56 | ||
57 | If you wish your place in any file to always be automatically saved, | |
58 | simply put this in your `~/.emacs' file: | |
59 | ||
60 | \(setq-default save-place t\)") | |
61 | ||
62 | (make-variable-buffer-local 'save-place) | |
63 | ||
0d448e33 | 64 | (defvar save-place-file (convert-standard-filename "~/.emacs-places") |
722074ef RS |
65 | "*Name of the file that records `save-place-alist' value.") |
66 | ||
e7dc77f6 RS |
67 | (defvar save-place-version-control 'nospecial |
68 | "*Controls whether to make numbered backups of master save-place file. | |
69 | It can have four values: t, nil, `never', and `nospecial'. The first | |
70 | three have the same meaning that they do for the variable | |
71 | `version-control', and the final value `nospecial' means just use the | |
72 | value of `version-control'.") | |
73 | ||
722074ef RS |
74 | (defvar save-place-loaded nil |
75 | "Non-nil means that the `save-place-file' has been loaded.") | |
76 | ||
6cf02570 RS |
77 | (defvar save-place-limit nil |
78 | "Maximum number of entries to retain in the list; nil means no limit.") | |
79 | ||
722074ef RS |
80 | (defun toggle-save-place (&optional parg) |
81 | "Toggle whether to save your place in this file between sessions. | |
82 | If this mode is enabled, point is recorded when you kill the buffer | |
83 | or exit Emacs. Visiting this file again will go to that position, | |
84 | even in a later Emacs session. | |
85 | ||
86 | If called with a prefix arg, the mode is enabled if and only if | |
87 | the argument is positive. | |
88 | ||
89 | To save places automatically in all files, put this in your `.emacs' file: | |
90 | ||
91 | \(setq-default save-place t\)" | |
92 | (interactive "P") | |
93 | (if (not buffer-file-name) | |
94 | (message | |
95 | (format "Buffer \"%s\" not visiting a file." (buffer-name))) | |
96 | (if (and save-place (or (not parg) (<= parg 0))) | |
97 | (progn | |
98 | (message "No place will be saved in this file.") | |
99 | (setq save-place nil)) | |
100 | (message "Place will be saved.") | |
101 | (setq save-place t)))) | |
102 | ||
103 | (defun save-place-to-alist () | |
104 | ;; put filename and point in a cons box and then cons that onto the | |
105 | ;; front of the save-place-alist, if save-place is non-nil. | |
106 | ;; Otherwise, just delete that file from the alist. | |
107 | ;; first check to make sure alist has been loaded in from the master | |
108 | ;; file. If not, do so, then feel free to modify the alist. It | |
109 | ;; will be saved again when Emacs is killed. | |
110 | (or save-place-loaded (load-save-place-alist-from-file)) | |
111 | (if buffer-file-name | |
112 | (progn | |
113 | (let ((cell (assoc buffer-file-name save-place-alist))) | |
114 | (if cell | |
115 | (setq save-place-alist (delq cell save-place-alist)))) | |
116 | (if save-place | |
117 | (setq save-place-alist | |
19d0c48a RS |
118 | (cons (cons buffer-file-name |
119 | (if (not (eq major-mode 'hexl-mode)) | |
120 | (point) | |
121 | (1+ (hexl-current-address)))) | |
722074ef RS |
122 | save-place-alist)))))) |
123 | ||
124 | (defun save-place-alist-to-file () | |
125 | (let ((file (expand-file-name save-place-file))) | |
126 | (save-excursion | |
127 | (message (format "Saving places to %s..." file)) | |
128 | (set-buffer (get-buffer-create " *Saved Places*")) | |
129 | (delete-region (point-min) (point-max)) | |
130 | (if (file-readable-p file) | |
131 | (insert-file-contents file)) | |
132 | (delete-region (point-min) (point-max)) | |
133 | (goto-char (point-min)) | |
134 | (print save-place-alist (current-buffer)) | |
e7dc77f6 RS |
135 | (let ((version-control |
136 | (cond | |
137 | ((null save-place-version-control) nil) | |
138 | ((eq 'never save-place-version-control) 'never) | |
139 | ((eq 'nospecial save-place-version-control) version-control) | |
140 | (t | |
141 | t)))) | |
142 | (write-file file) | |
143 | (kill-buffer (current-buffer)) | |
6cf02570 | 144 | (message (format "Saving places to %s...done" file)))))) |
722074ef RS |
145 | |
146 | (defun load-save-place-alist-from-file () | |
147 | (if (not save-place-loaded) | |
148 | (progn | |
149 | (setq save-place-loaded t) | |
150 | (let ((file (expand-file-name save-place-file))) | |
151 | ;; make sure that the alist does not get overwritten, and then | |
152 | ;; load it if it exists: | |
153 | (if (file-readable-p file) | |
154 | (save-excursion | |
155 | (message (format "Loading places from %s..." | |
156 | save-place-file)) | |
157 | ;; don't want to use find-file because we have been | |
158 | ;; adding hooks to it. | |
159 | (set-buffer (get-buffer-create " *Saved Places*")) | |
160 | (delete-region (point-min) (point-max)) | |
161 | (insert-file-contents file) | |
162 | (goto-char (point-min)) | |
163 | (setq save-place-alist | |
164 | (car (read-from-string | |
165 | (buffer-substring (point-min) (point-max))))) | |
6cf02570 RS |
166 | |
167 | ;; If there is a limit, and we're over it, then we'll | |
168 | ;; have to truncate the end of the list: | |
169 | (if save-place-limit | |
170 | (if (<= save-place-limit 0) | |
171 | ;; Zero gets special cased. I'm not thrilled | |
172 | ;; with this, but the loop for >= 1 is tight. | |
173 | (setq save-place-alist nil) | |
174 | ;; Else the limit is >= 1, so enforce it by | |
175 | ;; counting and then `setcdr'ing. | |
176 | (let ((s save-place-alist) | |
177 | (count 1)) | |
178 | (while s | |
179 | (if (>= count save-place-limit) | |
180 | (setcdr s nil) | |
181 | (setq count (1+ count))) | |
182 | (setq s (cdr s)))))) | |
183 | ||
722074ef | 184 | (kill-buffer (current-buffer)) |
6cf02570 | 185 | (message (format "Loading places from %s...done" file)) |
722074ef RS |
186 | t) |
187 | t) | |
188 | nil)))) | |
189 | ||
190 | (defun save-places-to-alist () | |
191 | ;; go through buffer-list, saving places to alist if save-place is | |
192 | ;; non-nil, deleting them from alist if it is nil. | |
193 | (let ((buf-list (buffer-list))) | |
194 | (while buf-list | |
195 | ;; put this into a save-excursion in case someone is counting on | |
196 | ;; another function in kill-emacs-hook to act on the last buffer | |
197 | ;; they were in: | |
198 | (save-excursion | |
199 | (set-buffer (car buf-list)) | |
200 | ;; save-place checks buffer-file-name too, but we can avoid | |
201 | ;; overhead of function call by checking here too. | |
202 | (and buffer-file-name (save-place-to-alist)) | |
203 | (setq buf-list (cdr buf-list)))))) | |
b6ace927 RS |
204 | |
205 | (defun save-place-find-file-hook () | |
206 | (or save-place-loaded (load-save-place-alist-from-file)) | |
207 | (let ((cell (assoc buffer-file-name save-place-alist))) | |
208 | (if cell | |
209 | (progn | |
47c5a471 RS |
210 | (or after-find-file-from-revert-buffer |
211 | (goto-char (cdr cell))) | |
b6ace927 RS |
212 | ;; and make sure it will be saved again for later |
213 | (setq save-place t))))) | |
214 | ||
4d2c9a10 | 215 | (defun save-place-kill-emacs-hook () |
b6ace927 RS |
216 | (save-places-to-alist) |
217 | (save-place-alist-to-file)) | |
218 | ||
219 | (add-hook 'find-file-hooks 'save-place-find-file-hook t) | |
220 | ||
221 | (add-hook 'kill-emacs-hook 'save-place-kill-emacs-hook) | |
722074ef RS |
222 | |
223 | (add-hook 'kill-buffer-hook 'save-place-to-alist) | |
224 | ||
225 | (provide 'saveplace) ; why not... | |
226 | ||
227 | ;;; saveplace.el ends here | |
b6ace927 | 228 |