lisp/time.el

   1 ;;; time.el --- display time, load and mail indicator in mode line of Emacs -*-coding: utf-8 -*-
   2
   3 ;; Copyright (C) 1985, 1986, 1987, 1993, 1994, 1996, 2000, 2001, 2002,
   4 ;;   2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
   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 3, 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., 51 Franklin Street, Fifth Floor,
  23 ;; Boston, MA 02110-1301, USA.
  24
  25 ;;; Commentary:
  26
  27 ;; Facilities to display current time/date and a new-mail indicator
  28 ;; in the Emacs mode line.  The entry point is `display-time'.
  29
  30 ;; Display time world in a buffer, the entry point is
  31 ;; `display-time-world'.
  32
  33 ;;; Code:
  34
  35 (defgroup display-time nil
  36   "Display time and load in mode line of Emacs."
  37   :group 'mode-line
  38   :group 'mail)
  39
  40
  41 (defcustom display-time-mail-file nil
  42   "*File name of mail inbox file, for indicating existence of new mail.
  43 Non-nil and not a string means don't check for mail; nil means use
  44 default, which is system-dependent, and is the same as used by Rmail."
  45   :type '(choice (const :tag "None" none)
  46                  (const :tag "Default" nil)
  47                  (file :format "%v"))
  48   :group 'display-time)
  49
  50 (defcustom display-time-mail-directory nil
  51   "*Name of mail inbox directory, for indicating existence of new mail.
  52 Any nonempty regular file in the directory is regarded as newly arrived mail.
  53 If nil, do not check a directory for arriving mail."
  54   :type '(choice (const :tag "None" nil)
  55                  (directory :format "%v"))
  56   :group 'display-time)
  57
  58 (defcustom display-time-mail-function nil
  59   "*Function to call, for indicating existence of new mail.
  60 If nil, that means use the default method: check that the file
  61 specified by `display-time-mail-file' is nonempty or that the
  62 directory `display-time-mail-directory' contains nonempty files."
  63   :type '(choice (const :tag "Default" nil)
  64                  (function))
  65   :group 'display-time)
  66
  67 (defcustom display-time-default-load-average 0
  68   "*Which load average value will be shown in the mode line.
  69 Almost every system can provide values of load for past 1 minute, past 5 or
  70 past 15 minutes.  The default is to display 1 minute load average."
  71   :type '(choice (const :tag "1 minute load" 0)
  72                  (const :tag "5 minutes load" 1)
  73                  (const :tag "15 minutes load" 2)
  74                  (const :tag "None" nil))
  75   :group 'display-time)
  76
  77 (defvar display-time-load-average nil
  78   "Load average currently being shown in mode line.")
  79
  80 (defcustom display-time-load-average-threshold 0.1
  81   "*Load-average values below this value won't be shown in the mode line."
  82   :type 'number
  83   :group 'display-time)
  84
  85 ;;;###autoload
  86 (defcustom display-time-day-and-date nil "\
  87 *Non-nil means \\[display-time] should display day and date as well as time."
  88   :type 'boolean
  89   :group 'display-time)
  90
  91 (defvar display-time-timer nil)
  92
  93 (defcustom display-time-interval 60
  94   "*Seconds between updates of time in the mode line."
  95   :type 'integer
  96   :group 'display-time)
  97
  98 (defcustom display-time-24hr-format nil
  99   "*Non-nil indicates time should be displayed as hh:mm, 0 <= hh <= 23.
 100 A value of nil means 1 <= hh <= 12, and an AM/PM suffix is used."
 101   :type 'boolean
 102   :group 'display-time)
 103
 104 (defvar display-time-string nil)
 105
 106 (defcustom display-time-hook nil
 107   "*List of functions to be called when the time is updated on the mode line."
 108   :type 'hook
 109   :group 'display-time)
 110
 111 (defvar display-time-server-down-time nil
 112    "Time when mail file's file system was recorded to be down.
 113 If that file system seems to be up, the value is nil.")
 114
 115 (defcustom zoneinfo-style-world-list
 116   '(("America/Los_Angeles" "Seattle")
 117     ("America/New_York" "New York")
 118     ("Europe/London" "London")
 119     ("Europe/Paris" "Paris")
 120     ("Asia/Calcutta" "Bangalore")
 121     ("Asia/Tokyo" "Tokyo"))
 122   "Alist of zoneinfo-style time zones and places for `display-time-world'.
 123 Each element has the form (TIMEZONE LABEL).
 124 TIMEZONE should be a string of the form AREA/LOCATION, where AREA is
 125 the name of a region -- a continent or ocean, and LOCATION is the name
 126 of a specific location, e.g., a city, within that region.
 127 LABEL is a string to display as the label of that TIMEZONE's time."
 128   :group 'display-time
 129   :type '(repeat (list string string))
 130   :version "23.1")
 131
 132 (defcustom legacy-style-world-list
 133   '(("PST8PDT" "Seattle")
 134     ("EST5EDT" "New York")
 135     ("GMT0BST" "London")
 136     ("CET-1CDT" "Paris")
 137     ("IST-5:30" "Bangalore")
 138     ("JST-9" "Tokyo"))
 139   "Alist of traditional-style time zones and places for `display-time-world'.
 140 Each element has the form (TIMEZONE LABEL).
 141 TIMEZONE should be a string of the form:
 142
 143      std[+|-]offset[dst[offset][,date[/time],date[/time]]]
 144
 145 See the documentation of the TZ environment variable on your system,
 146 for more details about the format of TIMEZONE.
 147 LABEL is a string to display as the label of that TIMEZONE's time."
 148   :group 'display-time
 149   :type '(repeat (list string string))
 150   :version "23.1")
 151
 152 (defcustom display-time-world-list
 153   ;; Determine if zoneinfo style timezones are supported by testing that
 154   ;; America/New York and Europe/London return different timezones.
 155   (let (gmt nyt)
 156     (set-time-zone-rule "America/New York")
 157     (setq nyt (format-time-string "%z"))
 158     (set-time-zone-rule "Europe/London")
 159     (setq gmt (format-time-string "%z"))
 160     (set-time-zone-rule nil)
 161     (if (string-equal nyt gmt)
 162         legacy-style-world-list
 163       zoneinfo-style-world-list))
 164   "Alist of time zones and places for `display-time-world' to display.
 165 Each element has the form (TIMEZONE LABEL).
 166 TIMEZONE should be in the format supported by `set-time-zone-rule' on
 167 your system.  See the documentation of `zoneinfo-style-world-list' and
 168 \`legacy-style-world-list' for two widely used formats.
 169 LABEL is a string to display as the label of that TIMEZONE's time."
 170   :group 'display-time
 171   :type '(repeat (list string string))
 172   :version "23.1")
 173
 174 (defcustom display-time-world-time-format "%A %d %B %R %Z"
 175   "Format of the time displayed, see `format-time-string'."
 176   :group 'display-time
 177   :type 'string
 178   :version "23.1")
 179
 180 (defcustom display-time-world-buffer-name "*wclock*"
 181   "Name of the wclock buffer."
 182   :group 'display-time
 183   :type 'string
 184   :version "23.1")
 185
 186 (defcustom display-time-world-timer-enable t
 187   "If non-nil, a timer will update the world clock."
 188   :group 'display-time
 189   :type 'boolean
 190   :version "23.1")
 191
 192 (defcustom display-time-world-timer-second 60
 193   "Interval in seconds for updating the world clock."
 194   :group 'display-time
 195   :type 'integer
 196   :version "23.1")
 197
 198 (defvar display-time-world-mode-map
 199   (let ((map (make-sparse-keymap)))
 200     (define-key map "q" 'kill-this-buffer)
 201     map)
 202   "Keymap of Display Time World mode")
 203
 204 ;;;###autoload
 205 (defun display-time ()
 206   "Enable display of time, load level, and mail flag in mode lines.
 207 This display updates automatically every minute.
 208 If `display-time-day-and-date' is non-nil, the current day and date
 209 are displayed as well.
 210 This runs the normal hook `display-time-hook' after each update."
 211   (interactive)
 212   (display-time-mode 1))
 213
 214 ;; This business used to be simpler when all mode lines had the same
 215 ;; face and the image could just be pbm.  Now we try to rely on an xpm
 216 ;; image with a transparent background.  Otherwise, set the background
 217 ;; for pbm.
 218
 219 (defcustom display-time-mail-face nil
 220   "Face to use for `display-time-mail-string'.
 221 If `display-time-use-mail-icon' is non-nil, the image's
 222 background color is the background of this face.  Set this to
 223 make the mail indicator stand out on a color display."
 224   :group 'mode-line-faces
 225   :group 'display-time
 226   :version "22.1"
 227   :type '(choice (const :tag "None" nil) face))
 228
 229 (defvar display-time-mail-icon
 230   (find-image '((:type xpm :file "letter.xpm" :ascent center)
 231                 (:type pbm :file "letter.pbm" :ascent center)))
 232   "Image specification to offer as the mail indicator on a graphic display.
 233 See `display-time-use-mail-icon' and `display-time-mail-face'.")
 234
 235 ;; Fixme: Default to icon on graphical display?
 236 (defcustom display-time-use-mail-icon nil
 237   "Non-nil means use an icon as mail indicator on a graphic display.
 238 Otherwise use `display-time-mail-string'.  The icon may consume less
 239 of the mode line.  It is specified by `display-time-mail-icon'."
 240   :group 'display-time
 241   :type 'boolean)
 242
 243 ;; Fixme: maybe default to the character if we can display Unicode.
 244 (defcustom display-time-mail-string "Mail"
 245   "String to use as the mail indicator in `display-time-string-forms'.
 246 This can use the Unicode letter character if you can display it."
 247   :group 'display-time
 248   :version "22.1"
 249   :type '(choice (const "Mail")
 250                  ;; Use :tag here because the Lucid menu won't display
 251                  ;; multibyte text.
 252                  (const :tag "Unicode letter character" "✉")
 253                  string))
 254
 255 (defcustom display-time-format nil
 256   "*String specifying format for displaying the time in the mode line.
 257 See the function `format-time-string' for an explanation of
 258 how to write this string.  If this is nil, the defaults
 259 depend on `display-time-day-and-date' and `display-time-24hr-format'."
 260   :type '(choice (const :tag "Default" nil)
 261                  string)
 262   :group 'display-time)
 263
 264 (defcustom display-time-string-forms
 265   '((if (and (not display-time-format) display-time-day-and-date)
 266         (format-time-string "%a %b %e " now)
 267       "")
 268     (propertize
 269      (format-time-string (or display-time-format
 270                              (if display-time-24hr-format "%H:%M" "%-I:%M%p"))
 271                          now)
 272      'help-echo (format-time-string "%a %b %e, %Y" now))
 273     load
 274     (if mail
 275         ;; Build the string every time to act on customization.
 276         ;; :set-after doesn't help for `customize-option'.  I think it
 277         ;; should.
 278         (concat
 279          " "
 280          (propertize
 281           display-time-mail-string
 282           'display `(when (and display-time-use-mail-icon
 283                                (display-graphic-p))
 284                       ,@display-time-mail-icon
 285                       ,@(if (and display-time-mail-face
 286                                  (memq (plist-get (cdr display-time-mail-icon)
 287                                                   :type)
 288                                        '(pbm xbm)))
 289                             (let ((bg (face-attribute display-time-mail-face
 290                                                       :background)))
 291                               (if (stringp bg)
 292                                   (list :background bg)))))
 293           'face display-time-mail-face
 294           'help-echo "You have new mail; mouse-2: Read mail"
 295           'mouse-face 'mode-line-highlight
 296           'local-map (make-mode-line-mouse-map 'mouse-2
 297                                                read-mail-command)))
 298       ""))
 299   "*List of expressions governing display of the time in the mode line.
 300 For most purposes, you can control the time format using `display-time-format'
 301 which is a more standard interface.
 302
 303 This expression is a list of expressions that can involve the keywords
 304 `load', `day', `month', and `year', `12-hours', `24-hours', `minutes',
 305 `seconds', all numbers in string form, and `monthname', `dayname', `am-pm',
 306 and `time-zone' all alphabetic strings, and `mail' a true/nil value.
 307
 308 For example, the form
 309
 310   '((substring year -2) \"/\" month \"/\" day
 311     \" \" 24-hours \":\" minutes \":\" seconds
 312     (if time-zone \" (\") time-zone (if time-zone \")\")
 313     (if mail \" Mail\" \"\"))
 314
 315 would give mode line times like `94/12/30 21:07:48 (UTC)'."
 316   :type 'sexp
 317   :group 'display-time)
 318
 319 (defun display-time-event-handler ()
 320   (display-time-update)
 321   ;; Do redisplay right now, if no input pending.
 322   (sit-for 0)
 323   (let* ((current (current-time))
 324          (timer display-time-timer)
 325          ;; Compute the time when this timer will run again, next.
 326          (next-time (timer-relative-time
 327                      (list (aref timer 1) (aref timer 2) (aref timer 3))
 328                      (* 5 (aref timer 4)) 0)))
 329     ;; If the activation time is far in the past,
 330     ;; skip executions until we reach a time in the future.
 331     ;; This avoids a long pause if Emacs has been suspended for hours.
 332     (or (> (nth 0 next-time) (nth 0 current))
 333         (and (= (nth 0 next-time) (nth 0 current))
 334              (> (nth 1 next-time) (nth 1 current)))
 335         (and (= (nth 0 next-time) (nth 0 current))
 336              (= (nth 1 next-time) (nth 1 current))
 337              (> (nth 2 next-time) (nth 2 current)))
 338         (progn
 339           (timer-set-time timer (timer-next-integral-multiple-of-time
 340                                  current display-time-interval)
 341                           display-time-interval)
 342           (timer-activate timer)))))
 343
 344 (defun display-time-next-load-average ()
 345   (interactive)
 346   (if (= 3 (setq display-time-load-average (1+ display-time-load-average)))
 347       (setq display-time-load-average 0))
 348   (display-time-update)
 349   (sit-for 0))
 350
 351 (defun display-time-mail-check-directory ()
 352   (let ((mail-files (directory-files display-time-mail-directory t))
 353         (size 0))
 354     (while (and mail-files (= size 0))
 355       ;; Count size of regular files only.
 356       (setq size (+ size (or (and (file-regular-p (car mail-files))
 357                                   (nth 7 (file-attributes (car mail-files))))
 358                              0)))
 359       (setq mail-files (cdr mail-files)))
 360     (if (> size 0)
 361         size
 362       nil)))
 363
 364 (defun display-time-update ()
 365   "Update the display-time info for the mode line.
 366 However, don't redisplay right now.
 367
 368 This is used for things like Rmail `g' that want to force an
 369 update which can wait for the next redisplay."
 370   (let* ((now (current-time))
 371          (time (current-time-string now))
 372          (load (if (null display-time-load-average)
 373                    ""
 374                  (condition-case ()
 375                      ;; Do not show values less than
 376                      ;; `display-time-load-average-threshold'.
 377                      (if (> (* display-time-load-average-threshold 100)
 378                             (nth display-time-load-average (load-average)))
 379                          ""
 380                        ;; The load average number is mysterious, so
 381                        ;; provide some help.
 382                        (let ((str (format " %03d"
 383                                           (nth display-time-load-average
 384                                                (load-average)))))
 385                          (propertize
 386                           (concat (substring str 0 -2) "." (substring str -2))
 387                           'local-map (make-mode-line-mouse-map
 388                                       'mouse-2 'display-time-next-load-average)
 389                           'mouse-face 'mode-line-highlight
 390                           'help-echo (concat
 391                                       "System load average for past "
 392                                       (if (= 0 display-time-load-average)
 393                                           "1 minute"
 394                                         (if (= 1 display-time-load-average)
 395                                             "5 minutes"
 396                                           "15 minutes"))
 397                                       "; mouse-2: next"))))
 398                    (error ""))))
 399          (mail-spool-file (or display-time-mail-file
 400                               (getenv "MAIL")
 401                               (concat rmail-spool-directory
 402                                       (user-login-name))))
 403          (mail (or (and display-time-mail-function
 404                         (funcall display-time-mail-function))
 405                    (and display-time-mail-directory
 406                         (display-time-mail-check-directory))
 407                    (and (stringp mail-spool-file)
 408                         (or (null display-time-server-down-time)
 409                             ;; If have been down for 20 min, try again.
 410                             (> (- (nth 1 now) display-time-server-down-time)
 411                                1200)
 412                             (and (< (nth 1 now) display-time-server-down-time)
 413                                  (> (- (nth 1 now)
 414                                        display-time-server-down-time)
 415                                     -64336)))
 416                         (let ((start-time (current-time)))
 417                           (prog1
 418                               (display-time-file-nonempty-p mail-spool-file)
 419                             (if (> (- (nth 1 (current-time))
 420                                       (nth 1 start-time))
 421                                    20)
 422                                 ;; Record that mail file is not accessible.
 423                                 (setq display-time-server-down-time
 424                                       (nth 1 (current-time)))
 425                               ;; Record that mail file is accessible.
 426                               (setq display-time-server-down-time nil)))))))
 427          (24-hours (substring time 11 13))
 428          (hour (string-to-number 24-hours))
 429          (12-hours (int-to-string (1+ (% (+ hour 11) 12))))
 430          (am-pm (if (>= hour 12) "pm" "am"))
 431          (minutes (substring time 14 16))
 432          (seconds (substring time 17 19))
 433          (time-zone (car (cdr (current-time-zone now))))
 434          (day (substring time 8 10))
 435          (year (substring time 20 24))
 436          (monthname (substring time 4 7))
 437          (month
 438           (cdr
 439            (assoc
 440             monthname
 441             '(("Jan" . "1") ("Feb" . "2") ("Mar" . "3") ("Apr" . "4")
 442               ("May" . "5") ("Jun" . "6") ("Jul" . "7") ("Aug" . "8")
 443               ("Sep" . "9") ("Oct" . "10") ("Nov" . "11") ("Dec" . "12")))))
 444          (dayname (substring time 0 3)))
 445     (setq display-time-string
 446           (mapconcat 'eval display-time-string-forms ""))
 447     ;; This is inside the let binding, but we are not going to document
 448     ;; what variables are available.
 449     (run-hooks 'display-time-hook))
 450   (force-mode-line-update))
 451
 452 (defun display-time-file-nonempty-p (file)
 453   (and (file-exists-p file)
 454        (< 0 (nth 7 (file-attributes (file-chase-links file))))))
 455
 456 ;;;###autoload
 457 (define-minor-mode display-time-mode
 458   "Toggle display of time, load level, and mail flag in mode lines.
 459 With a numeric arg, enable this display if arg is positive.
 460
 461 When this display is enabled, it updates automatically every minute.
 462 If `display-time-day-and-date' is non-nil, the current day and date
 463 are displayed as well.
 464 This runs the normal hook `display-time-hook' after each update."
 465   :global t :group 'display-time
 466   (and display-time-timer (cancel-timer display-time-timer))
 467   (setq display-time-timer nil)
 468   (setq display-time-string "")
 469   (or global-mode-string (setq global-mode-string '("")))
 470   (setq display-time-load-average display-time-default-load-average)
 471   (if display-time-mode
 472       (progn
 473         (or (memq 'display-time-string global-mode-string)
 474             (setq global-mode-string
 475                   (append global-mode-string '(display-time-string))))
 476         ;; Set up the time timer.
 477         (setq display-time-timer
 478               (run-at-time t display-time-interval
 479                            'display-time-event-handler))
 480         ;; Make the time appear right away.
 481         (display-time-update)
 482         ;; When you get new mail, clear "Mail" from the mode line.
 483         (add-hook 'rmail-after-get-new-mail-hook
 484                   'display-time-event-handler))
 485     (remove-hook 'rmail-after-get-new-mail-hook
 486                  'display-time-event-handler)))
 487
 488
 489 (defun display-time-world-mode ()
 490   "Major mode for buffer that displays times in various time zones.
 491 See `display-time-world'."
 492   (interactive)
 493   (kill-all-local-variables)
 494   (setq
 495    major-mode 'display-time-world-mode
 496    mode-name "World clock")
 497   (use-local-map display-time-world-mode-map))
 498
 499 (defun display-time-world-display (alist)
 500   "Replace current buffer text with times in various zones, based on ALIST."
 501   (let ((inhibit-read-only t)
 502         (buffer-undo-list t))
 503     (erase-buffer)
 504     (let ((max-width 0)
 505           (result ()))
 506       (unwind-protect
 507           (dolist (zone alist)
 508             (let* ((label (cadr zone))
 509                    (width (string-width label)))
 510               (set-time-zone-rule (car zone))
 511               (setq result
 512                     (append result
 513                             (list
 514                              label width
 515                              (format-time-string display-time-world-time-format))))
 516               (when (> width max-width)
 517                 (setq max-width width))))
 518         (set-time-zone-rule nil))
 519       (while result
 520         (insert (pop result)
 521                 (make-string (1+ (- max-width (pop result))) ?\s)
 522                 (pop result) "\n")))
 523     (delete-backward-char 1)))
 524
 525 ;;;###autoload
 526 (defun display-time-world ()
 527   "Enable updating display of times in various time zones.
 528 `display-time-world-list' specifies the zones.
 529 To turn off the world time display, go to that window and type `q'."
 530   (interactive)
 531   (when (and display-time-world-timer-enable
 532              (not (get-buffer display-time-world-buffer-name)))
 533     (run-at-time t display-time-world-timer-second 'display-time-world-timer))
 534   (with-current-buffer (get-buffer-create display-time-world-buffer-name)
 535     (display-time-world-display display-time-world-list))
 536   (pop-to-buffer display-time-world-buffer-name)
 537   (fit-window-to-buffer)
 538   (display-time-world-mode))
 539
 540 (defun display-time-world-timer ()
 541   (if (get-buffer display-time-world-buffer-name)
 542       (with-current-buffer (get-buffer display-time-world-buffer-name)
 543         (display-time-world-display display-time-world-list))
 544     ;; cancel timer
 545     (let ((list timer-list))
 546       (while list
 547         (let ((elt (pop list)))
 548           (when (equal (symbol-name (aref elt 5)) "display-time-world-timer")
 549             (cancel-timer elt)))))))
 550
 551 (provide 'time)
 552
 553 ;;; arch-tag: b9c1623f-b5cb-48e4-b650-482a4d23c5a6
 554 ;;; time.el ends here