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[bpt/emacs.git] / lisp / time.el
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55535639 1;;; time.el --- display time, load and mail indicator in mode line of Emacs
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3;; Copyright (C) 1985, 86, 87, 93, 94, 96, 2000, 2001
4;; Free Software Foundation, Inc.
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5
6;; Maintainer: FSF
7
8;; This file is part of GNU Emacs.
9
10;; GNU Emacs is free software; you can redistribute it and/or modify
11;; it under the terms of the GNU General Public License as published by
12;; the Free Software Foundation; either version 2, or (at your option)
13;; any later version.
14
15;; GNU Emacs is distributed in the hope that it will be useful,
16;; but WITHOUT ANY WARRANTY; without even the implied warranty of
17;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18;; GNU General Public License for more details.
19
20;; You should have received a copy of the GNU General Public License
21;; along with GNU Emacs; see the file COPYING. If not, write to the
22;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23;; Boston, MA 02111-1307, USA.
24
25;;; Commentary:
26
27;; Facilities to display current time/date and a new-mail indicator
28;; in the Emacs mode line. The single entry point is `display-time'.
29
30;;; Code:
31
32(defgroup display-time nil
33 "Display time and load in mode line of Emacs."
34 :group 'modeline
35 :group 'mail)
36
37
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38(defcustom display-time-mail-file nil
39 "*File name of mail inbox file, for indicating existence of new mail.
40Non-nil and not a string means don't check for mail. nil means use
41default, which is system-dependent, and is the same as used by Rmail."
42 :type '(choice (const :tag "(None)" none)
43 (const :tag "Default" nil)
44 (file :format "%v"))
45 :group 'display-time)
46
47(defcustom display-time-mail-function nil
48 "*Function to call, for indicating existence of new mail.
49nil means use the default method of checking `display-time-mail-file'."
50 :type '(choice (const :tag "Default" nil)
51 (function))
52 :group 'display-time)
53
54;;;###autoload
55(defcustom display-time-day-and-date nil "\
56*Non-nil means \\[display-time] should display day and date as well as time."
57 :type 'boolean
58 :group 'display-time)
59
60(defvar display-time-timer nil)
61
62(defcustom display-time-interval 60
63 "*Seconds between updates of time in the mode line."
64 :type 'integer
65 :group 'display-time)
66
67(defcustom display-time-24hr-format nil
68 "*Non-nil indicates time should be displayed as hh:mm, 0 <= hh <= 23.
69Nil means 1 <= hh <= 12, and an AM/PM suffix is used."
70 :type 'boolean
71 :group 'display-time)
72
73(defvar display-time-string nil)
74
75(defcustom display-time-hook nil
76 "*List of functions to be called when the time is updated on the mode line."
77 :type 'hook
78 :group 'display-time)
79
80(defvar display-time-server-down-time nil
81 "Time when mail file's file system was recorded to be down.
82If that file system seems to be up, the value is nil.")
83
84;;;###autoload
85(defun display-time ()
86 "Enable display of time, load level, and mail flag in mode lines.
87This display updates automatically every minute.
88If `display-time-day-and-date' is non-nil, the current day and date
89are displayed as well.
90This runs the normal hook `display-time-hook' after each update."
91 (interactive)
92 (display-time-mode 1))
93
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94(defcustom display-time-mail-face 'mode-line
95 "Face to use for `display-time-mail-string'.
96If `display-time-use-mail-icon' is non-nil, the image's background
97colour is the background of this face. Set this to a face other than
98`mode-line' to make the mail indicator stand out on a suitable
99display."
100 :group 'faces
101 :group 'display-time
102 :type 'face)
103
104(defvar display-time-mail-icon
105 (find-image '((:type xbm :file "letter.xbm" :ascent center)))
106 "Image specification to offer as the mail indicator on a graphic
107display. See `display-time-use-mail-icon' and
108`display-time-mail-face'.")
109
110(defcustom display-time-use-mail-icon nil
111 "Non-nil means use an icon as the mail indicator on a graphic display.
112Otherwise use the string \"Mail\". The icon may consume less of the
113mode line. It is specified by `display-time-mail-icon'."
114 :group 'display-time
115 :type 'boolean)
116
117(defcustom display-time-format nil
118 "*A string specifying the format for displaying the time in the mode line.
119See the function `format-time-string' for an explanation of
120how to write this string. If this is nil, the defaults
121depend on `display-time-day-and-date' and `display-time-24hr-format'."
122 :type '(choice (const :tag "Default" nil)
123 string)
124 :group 'display-time)
125
126(defcustom display-time-string-forms
127 '((if (and (not display-time-format) display-time-day-and-date)
128 (format-time-string "%a %b %e " now)
129 "")
130 (format-time-string (or display-time-format
131 (if display-time-24hr-format "%H:%M" "%-I:%M%p"))
132 now)
133 load
134 (if mail
135 ;; Build the string every time to act on customization.
136 (concat " "
137 (propertize
138 "Mail"
139 'display `(when (and display-time-use-mail-icon
140 (display-graphic-p))
141 ,@display-time-mail-icon
142 ,@(list :background (face-attribute
143 display-time-mail-face
144 :background)))
145 'help-echo "mouse-2: Read mail"
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146 'local-map (make-mode-line-mouse-map 'mouse-2
147 read-mail-command)))
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148 ""))
149 "*A list of expressions governing display of the time in the mode line.
150For most purposes, you can control the time format using `display-time-format'
151which is a more standard interface.
152
153This expression is a list of expressions that can involve the keywords
154`load', `day', `month', and `year', `12-hours', `24-hours', `minutes',
155`seconds', all numbers in string form, and `monthname', `dayname', `am-pm',
156and `time-zone' all alphabetic strings, and `mail' a true/nil value.
157
158For example, the form
159
160 '((substring year -2) \"/\" month \"/\" day
161 \" \" 24-hours \":\" minutes \":\" seconds
162 (if time-zone \" (\") time-zone (if time-zone \")\")
163 (if mail \" Mail\" \"\"))
164
165would give mode line times like `94/12/30 21:07:48 (UTC)'."
166 :type 'sexp
167 :group 'display-time)
168
169(defun display-time-event-handler ()
170 (display-time-update)
171 ;; Do redisplay right now, if no input pending.
172 (sit-for 0)
173 (let* ((current (current-time))
174 (timer display-time-timer)
175 ;; Compute the time when this timer will run again, next.
176 (next-time (timer-relative-time
177 (list (aref timer 1) (aref timer 2) (aref timer 3))
178 (* 5 (aref timer 4)) 0)))
179 ;; If the activation time is far in the past,
180 ;; skip executions until we reach a time in the future.
181 ;; This avoids a long pause if Emacs has been suspended for hours.
182 (or (> (nth 0 next-time) (nth 0 current))
183 (and (= (nth 0 next-time) (nth 0 current))
184 (> (nth 1 next-time) (nth 1 current)))
185 (and (= (nth 0 next-time) (nth 0 current))
186 (= (nth 1 next-time) (nth 1 current))
187 (> (nth 2 next-time) (nth 2 current)))
188 (progn
189 (timer-set-time timer (timer-next-integral-multiple-of-time
190 current display-time-interval)
191 display-time-interval)
192 (timer-activate timer)))))
193
194;; Update the display-time info for the mode line
195;; but don't redisplay right now. This is used for
196;; things like Rmail `g' that want to force an update
197;; which can wait for the next redisplay.
198(defun display-time-update ()
199 (let* ((now (current-time))
200 (time (current-time-string now))
201 (load (condition-case ()
202 (if (zerop (car (load-average))) ""
203 ;; The load average number is mysterious, so
204 ;; propvide some help.
205 (let ((str (format " %03d" (car (load-average)))))
206 (propertize
207 (concat (substring str 0 -2) "." (substring str -2))
208 'help-echo "System load average")))
209 (error "")))
210 (mail-spool-file (or display-time-mail-file
211 (getenv "MAIL")
212 (concat rmail-spool-directory
213 (user-login-name))))
214 (mail (or (and display-time-mail-function
215 (funcall display-time-mail-function))
216 (and (stringp mail-spool-file)
217 (or (null display-time-server-down-time)
218 ;; If have been down for 20 min, try again.
219 (> (- (nth 1 now) display-time-server-down-time)
220 1200)
221 (and (< (nth 1 now) display-time-server-down-time)
222 (> (- (nth 1 now) display-time-server-down-time)
223 -64336)))
224 (let ((start-time (current-time)))
225 (prog1
226 (display-time-file-nonempty-p mail-spool-file)
227 (if (> (- (nth 1 (current-time)) (nth 1 start-time))
228 20)
229 ;; Record that mail file is not accessible.
230 (setq display-time-server-down-time
231 (nth 1 (current-time)))
232 ;; Record that mail file is accessible.
233 (setq display-time-server-down-time nil)))))))
234 (24-hours (substring time 11 13))
235 (hour (string-to-int 24-hours))
236 (12-hours (int-to-string (1+ (% (+ hour 11) 12))))
237 (am-pm (if (>= hour 12) "pm" "am"))
238 (minutes (substring time 14 16))
239 (seconds (substring time 17 19))
240 (time-zone (car (cdr (current-time-zone now))))
241 (day (substring time 8 10))
242 (year (substring time 20 24))
243 (monthname (substring time 4 7))
244 (month
245 (cdr
246 (assoc
247 monthname
248 '(("Jan" . "1") ("Feb" . "2") ("Mar" . "3") ("Apr" . "4")
249 ("May" . "5") ("Jun" . "6") ("Jul" . "7") ("Aug" . "8")
250 ("Sep" . "9") ("Oct" . "10") ("Nov" . "11") ("Dec" . "12")))))
251 (dayname (substring time 0 3)))
252 (setq display-time-string
253 (mapconcat 'eval display-time-string-forms ""))
254 ;; This is inside the let binding, but we are not going to document
255 ;; what variables are available.
256 (run-hooks 'display-time-hook))
257 (force-mode-line-update))
258
259(defun display-time-file-nonempty-p (file)
260 (and (file-exists-p file)
261 (< 0 (nth 7 (file-attributes (file-chase-links file))))))
262
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263;;;###autoload
264(define-minor-mode display-time-mode
265 "Toggle display of time, load level, and mail flag in mode lines.
266With a numeric arg, enable this display if arg is positive.
267
268When this display is enabled, it updates automatically every minute.
269If `display-time-day-and-date' is non-nil, the current day and date
270are displayed as well.
271This runs the normal hook `display-time-hook' after each update."
bb7a71c5 272 :global t :group 'display-time
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273 (and display-time-timer (cancel-timer display-time-timer))
274 (setq display-time-timer nil)
275 (setq display-time-string "")
276 (or global-mode-string (setq global-mode-string '("")))
277 (if display-time-mode
278 (progn
279 (or (memq 'display-time-string global-mode-string)
280 (setq global-mode-string
281 (append global-mode-string '(display-time-string))))
282 ;; Set up the time timer.
283 (setq display-time-timer
284 (run-at-time t display-time-interval
285 'display-time-event-handler))
286 ;; Make the time appear right away.
287 (display-time-update)
288 ;; When you get new mail, clear "Mail" from the mode line.
289 (add-hook 'rmail-after-get-new-mail-hook
290 'display-time-event-handler))
291 (remove-hook 'rmail-after-get-new-mail-hook
292 'display-time-event-handler)))
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293
294(provide 'time)
295
296;;; time.el ends here