lisp/time.el

   1 ;;; time.el --- display time, load and mail indicator in mode line of Emacs
   2
   3 ;; Copyright (C) 1985, 86, 87, 93, 94, 96, 2000, 2001, 2002
   4 ;;   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 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
  38 (defcustom display-time-mail-file nil
  39   "*File name of mail inbox file, for indicating existence of new mail.
  40 Non-nil and not a string means don't check for mail.  nil means use
  41 default, 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-directory nil
  48   "*Name of mail inbox directory, for indicating existence of new mail.
  49 Any nonempty regular file in the directory is regarded as newly arrived mail.
  50 If nil, do not check a directory for arriving mail."
  51   :type '(choice (const :tag "None" nil)
  52                  (directory :format "%v"))
  53   :group 'display-time)
  54
  55 (defcustom display-time-mail-function nil
  56   "*Function to call, for indicating existence of new mail.
  57 If nil, that means use the default method: check that the file
  58 specified by `display-time-mail-file' is nonempty or that the
  59 directory `display-time-mail-directory' contains nonempty files."
  60   :type '(choice (const :tag "Default" nil)
  61                  (function))
  62   :group 'display-time)
  63
  64 (defcustom display-time-default-load-average 0
  65   "*Which load-average value will be shown in the mode line.
  66 Almost every system can provide values of load for past 1 minute, past 5 or
  67 past 15 minutes.  The default is to display 1 minute load average."
  68   :type '(choice (const :tag "1 minute load" 0)
  69                  (const :tag "5 minutes load" 1)
  70                  (const :tag "15 minutes load" 2))
  71   :group 'display-time)
  72
  73 (defvar display-time-load-average display-time-default-load-average)
  74
  75 (defcustom display-time-load-average-threshold 0.1
  76   "*Load-average values below this value won't be shown in the mode line."
  77   :type 'number
  78   :group 'display-time)
  79
  80 ;;;###autoload
  81 (defcustom display-time-day-and-date nil "\
  82 *Non-nil means \\[display-time] should display day and date as well as time."
  83   :type 'boolean
  84   :group 'display-time)
  85
  86 (defvar display-time-timer nil)
  87
  88 (defcustom display-time-interval 60
  89   "*Seconds between updates of time in the mode line."
  90   :type 'integer
  91   :group 'display-time)
  92
  93 (defcustom display-time-24hr-format nil
  94   "*Non-nil indicates time should be displayed as hh:mm, 0 <= hh <= 23.
  95 nil means 1 <= hh <= 12, and an AM/PM suffix is used."
  96   :type 'boolean
  97   :group 'display-time)
  98
  99 (defvar display-time-string nil)
 100
 101 (defcustom display-time-hook nil
 102   "*List of functions to be called when the time is updated on the mode line."
 103   :type 'hook
 104   :group 'display-time)
 105
 106 (defvar display-time-server-down-time nil
 107    "Time when mail file's file system was recorded to be down.
 108 If that file system seems to be up, the value is nil.")
 109
 110 ;;;###autoload
 111 (defun display-time ()
 112   "Enable display of time, load level, and mail flag in mode lines.
 113 This display updates automatically every minute.
 114 If `display-time-day-and-date' is non-nil, the current day and date
 115 are displayed as well.
 116 This runs the normal hook `display-time-hook' after each update."
 117   (interactive)
 118   (display-time-mode 1))
 119
 120 (defcustom display-time-mail-face 'mode-line
 121   "Face to use for `display-time-mail-string'.
 122 If `display-time-use-mail-icon' is non-nil, the image's background
 123 colour is the background of this face.  Set this to a face other than
 124 `mode-line' to make the mail indicator stand out on a suitable
 125 display."
 126   :group 'faces
 127   :group 'display-time
 128   :type 'face)
 129
 130 (defvar display-time-mail-icon
 131   (find-image '((:type xpm :file "letter.xpm" :ascent center)
 132                 (:type xbm :file "letter.xbm" :ascent center)))
 133   "Image specification to offer as the mail indicator on a graphic
 134 display.  See `display-time-use-mail-icon' and
 135 `display-time-mail-face'.")
 136
 137 (defcustom display-time-use-mail-icon nil
 138   "Non-nil means use an icon as the mail indicator on a graphic display.
 139 Otherwise use the string \"Mail\".  The icon may consume less of the
 140 mode line.  It is specified by `display-time-mail-icon'."
 141   :group 'display-time
 142   :type 'boolean)
 143
 144 (defcustom display-time-format nil
 145   "*A string specifying the format for displaying the time in the mode line.
 146 See the function `format-time-string' for an explanation of
 147 how to write this string.  If this is nil, the defaults
 148 depend on `display-time-day-and-date' and `display-time-24hr-format'."
 149   :type '(choice (const :tag "Default" nil)
 150                  string)
 151   :group 'display-time)
 152
 153 (defcustom display-time-string-forms
 154   '((if (and (not display-time-format) display-time-day-and-date)
 155         (format-time-string "%a %b %e " now)
 156       "")
 157     (format-time-string (or display-time-format
 158                             (if display-time-24hr-format "%H:%M" "%-I:%M%p"))
 159                         now)
 160     load
 161     (if mail
 162         ;; Build the string every time to act on customization.
 163         (concat " "
 164                 (propertize
 165                  "Mail"
 166                  'display `(when (and display-time-use-mail-icon
 167                                       (display-graphic-p))
 168                              ,@display-time-mail-icon
 169                              ,@(list :background (face-attribute
 170                                                   display-time-mail-face
 171                                                   :background)))
 172                  'help-echo "You have new mail; mouse-2: Read mail"
 173                  'local-map (make-mode-line-mouse-map 'mouse-2
 174                                                       read-mail-command)))
 175       ""))
 176   "*A list of expressions governing display of the time in the mode line.
 177 For most purposes, you can control the time format using `display-time-format'
 178 which is a more standard interface.
 179
 180 This expression is a list of expressions that can involve the keywords
 181 `load', `day', `month', and `year', `12-hours', `24-hours', `minutes',
 182 `seconds', all numbers in string form, and `monthname', `dayname', `am-pm',
 183 and `time-zone' all alphabetic strings, and `mail' a true/nil value.
 184
 185 For example, the form
 186
 187   '((substring year -2) \"/\" month \"/\" day
 188     \" \" 24-hours \":\" minutes \":\" seconds
 189     (if time-zone \" (\") time-zone (if time-zone \")\")
 190     (if mail \" Mail\" \"\"))
 191
 192 would give mode line times like `94/12/30 21:07:48 (UTC)'."
 193   :type 'sexp
 194   :group 'display-time)
 195
 196 (defun display-time-event-handler ()
 197   (display-time-update)
 198   ;; Do redisplay right now, if no input pending.
 199   (sit-for 0)
 200   (let* ((current (current-time))
 201          (timer display-time-timer)
 202          ;; Compute the time when this timer will run again, next.
 203          (next-time (timer-relative-time
 204                      (list (aref timer 1) (aref timer 2) (aref timer 3))
 205                      (* 5 (aref timer 4)) 0)))
 206     ;; If the activation time is far in the past,
 207     ;; skip executions until we reach a time in the future.
 208     ;; This avoids a long pause if Emacs has been suspended for hours.
 209     (or (> (nth 0 next-time) (nth 0 current))
 210         (and (= (nth 0 next-time) (nth 0 current))
 211              (> (nth 1 next-time) (nth 1 current)))
 212         (and (= (nth 0 next-time) (nth 0 current))
 213              (= (nth 1 next-time) (nth 1 current))
 214              (> (nth 2 next-time) (nth 2 current)))
 215         (progn
 216           (timer-set-time timer (timer-next-integral-multiple-of-time
 217                                  current display-time-interval)
 218                           display-time-interval)
 219           (timer-activate timer)))))
 220
 221 (defun display-time-next-load-average ()
 222   (interactive)
 223   (if (= 3 (setq display-time-load-average (1+ display-time-load-average)))
 224       (setq display-time-load-average 0))
 225   (display-time-update)
 226   (sit-for 0))
 227
 228 (defun display-time-mail-check-directory ()
 229   (let ((mail-files (directory-files display-time-mail-directory t))
 230         (size 0))
 231     (while (and mail-files (= size 0))
 232       ;; Count size of regular files only.
 233       (setq size (+ size (or (and (file-regular-p (car mail-files))
 234                                   (nth 7 (file-attributes (car mail-files))))
 235                              0)))
 236       (setq mail-files (cdr mail-files)))
 237     (if (> size 0)
 238         size
 239       nil)))
 240
 241 ;; Update the display-time info for the mode line
 242 ;; but don't redisplay right now.  This is used for
 243 ;; things like Rmail `g' that want to force an update
 244 ;; which can wait for the next redisplay.
 245 (defun display-time-update ()
 246   (let* ((now (current-time))
 247          (time (current-time-string now))
 248          (load (condition-case ()
 249                    ;; Do not show values less than
 250                    ;; `display-time-load-average-threshold'.
 251                    (if (> (* display-time-load-average-threshold 100)
 252                            (nth display-time-load-average (load-average)))
 253                        ""
 254                      ;; The load average number is mysterious, so
 255                      ;; provide some help.
 256                      (let ((str (format " %03d" (nth display-time-load-average (load-average)))))
 257                        (propertize
 258                         (concat (substring str 0 -2) "." (substring str -2))
 259                         'local-map (make-mode-line-mouse-map 'mouse-2
 260                                                              'display-time-next-load-average)
 261                         'help-echo (concat "System load average for past "
 262                                            (if (= 0 display-time-load-average)
 263                                                "1 minute"
 264                                              (if (= 1 display-time-load-average)
 265                                                  "5 minutes"
 266                                                "15 minutes")) "; mouse-2: next" ))))
 267                  (error "")))
 268          (mail-spool-file (or display-time-mail-file
 269                               (getenv "MAIL")
 270                               (concat rmail-spool-directory
 271                                       (user-login-name))))
 272          (mail (or (and display-time-mail-function
 273                         (funcall display-time-mail-function))
 274                    (and display-time-mail-directory
 275                         (display-time-mail-check-directory))
 276                    (and (stringp mail-spool-file)
 277                         (or (null display-time-server-down-time)
 278                             ;; If have been down for 20 min, try again.
 279                             (> (- (nth 1 now) display-time-server-down-time)
 280                                1200)
 281                             (and (< (nth 1 now) display-time-server-down-time)
 282                                  (> (- (nth 1 now) display-time-server-down-time)
 283                                     -64336)))
 284                         (let ((start-time (current-time)))
 285                           (prog1
 286                               (display-time-file-nonempty-p mail-spool-file)
 287                             (if (> (- (nth 1 (current-time)) (nth 1 start-time))
 288                                    20)
 289                                 ;; Record that mail file is not accessible.
 290                                 (setq display-time-server-down-time
 291                                       (nth 1 (current-time)))
 292                               ;; Record that mail file is accessible.
 293                               (setq display-time-server-down-time nil)))))))
 294          (24-hours (substring time 11 13))
 295          (hour (string-to-int 24-hours))
 296          (12-hours (int-to-string (1+ (% (+ hour 11) 12))))
 297          (am-pm (if (>= hour 12) "pm" "am"))
 298          (minutes (substring time 14 16))
 299          (seconds (substring time 17 19))
 300          (time-zone (car (cdr (current-time-zone now))))
 301          (day (substring time 8 10))
 302          (year (substring time 20 24))
 303          (monthname (substring time 4 7))
 304          (month
 305           (cdr
 306            (assoc
 307             monthname
 308             '(("Jan" . "1") ("Feb" . "2") ("Mar" . "3") ("Apr" . "4")
 309               ("May" . "5") ("Jun" . "6") ("Jul" . "7") ("Aug" . "8")
 310               ("Sep" . "9") ("Oct" . "10") ("Nov" . "11") ("Dec" . "12")))))
 311          (dayname (substring time 0 3)))
 312     (setq display-time-string
 313           (mapconcat 'eval display-time-string-forms ""))
 314     ;; This is inside the let binding, but we are not going to document
 315     ;; what variables are available.
 316     (run-hooks 'display-time-hook))
 317   (force-mode-line-update))
 318
 319 (defun display-time-file-nonempty-p (file)
 320   (and (file-exists-p file)
 321        (< 0 (nth 7 (file-attributes (file-chase-links file))))))
 322
 323 ;;;###autoload
 324 (define-minor-mode display-time-mode
 325   "Toggle display of time, load level, and mail flag in mode lines.
 326 With a numeric arg, enable this display if arg is positive.
 327
 328 When this display is enabled, it updates automatically every minute.
 329 If `display-time-day-and-date' is non-nil, the current day and date
 330 are displayed as well.
 331 This runs the normal hook `display-time-hook' after each update."
 332   :global t :group 'display-time
 333     (and display-time-timer (cancel-timer display-time-timer))
 334     (setq display-time-timer nil)
 335     (setq display-time-string "")
 336     (or global-mode-string (setq global-mode-string '("")))
 337     (if display-time-mode
 338         (progn
 339           (or (memq 'display-time-string global-mode-string)
 340               (setq global-mode-string
 341                     (append global-mode-string '(display-time-string))))
 342           ;; Set up the time timer.
 343           (setq display-time-timer
 344                 (run-at-time t display-time-interval
 345                              'display-time-event-handler))
 346           ;; Make the time appear right away.
 347           (display-time-update)
 348           ;; When you get new mail, clear "Mail" from the mode line.
 349           (add-hook 'rmail-after-get-new-mail-hook
 350                     'display-time-event-handler))
 351       (remove-hook 'rmail-after-get-new-mail-hook
 352                    'display-time-event-handler)))
 353
 354 (provide 'time)
 355
 356 ;;; time.el ends here