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mirror of https://git.savannah.gnu.org/git/emacs.git synced 2024-11-23 07:19:15 +00:00
emacs/lisp/time.el
1998-04-20 03:35:05 +00:00

263 lines
9.4 KiB
EmacsLisp

;;; time.el --- display time and load in mode line of Emacs.
;; Copyright (C) 1985, 86, 87, 93, 94, 1996 Free Software Foundation, Inc.
;; Maintainer: FSF
;; This file is part of GNU Emacs.
;; GNU Emacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 2, or (at your option)
;; any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING. If not, write to the
;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.
;;; Commentary:
;; Facilities to display current time/date and a new-mail indicator
;; in the Emacs mode line. The single entry point is `display-time'.
;;; Code:
(defgroup display-time nil
"Display time and load in mode line of Emacs."
:group 'modeline
:group 'mail)
(defcustom display-time-mode nil
"Toggle display of time, load level, and mail flag in mode lines.
You must modify via \\[customize] for this variable to have an effect."
:set (lambda (symbol value)
(display-time-mode (or value 0)))
:initialize 'custom-initialize-default
:type 'boolean
:group 'display-time
:require 'time
:version "20.3")
(defcustom display-time-mail-file nil
"*File name of mail inbox file, for indicating existence of new mail.
Non-nil and not a string means don't check for mail. nil means use
default, which is system-dependent, and is the same as used by Rmail."
:type '(choice (const :tag "Default" nil)
(file :format "%v"))
:group 'display-time)
;;;###autoload
(defcustom display-time-day-and-date nil "\
*Non-nil means \\[display-time] should display day and date as well as time."
:type 'boolean
:group 'display-time)
(defvar display-time-timer nil)
(defcustom display-time-interval 60
"*Seconds between updates of time in the mode line."
:type 'integer
:group 'display-time)
(defcustom display-time-24hr-format nil
"*Non-nil indicates time should be displayed as hh:mm, 0 <= hh <= 23.
Nil means 1 <= hh <= 12, and an AM/PM suffix is used."
:type 'boolean
:group 'display-time)
(defvar display-time-string nil)
(defcustom display-time-hook nil
"*List of functions to be called when the time is updated on the mode line."
:type 'hook
:group 'display-time)
(defvar display-time-server-down-time nil
"Time when mail file's file system was recorded to be down.
If that file system seems to be up, the value is nil.")
;;;###autoload
(defun display-time ()
"Enable display of time, load level, and mail flag in mode lines.
This display updates automatically every minute.
If `display-time-day-and-date' is non-nil, the current day and date
are displayed as well.
This runs the normal hook `display-time-hook' after each update."
(interactive)
(display-time-mode 1))
;;;###autoload
(defun display-time-mode (arg)
"Toggle display of time, load level, and mail flag in mode lines.
With a numeric arg, enable this display if arg is positive.
When this display is enabled, it updates automatically every minute.
If `display-time-day-and-date' is non-nil, the current day and date
are displayed as well.
This runs the normal hook `display-time-hook' after each update."
(interactive "P")
(let ((on (if (null arg)
(not display-time-timer)
(> (prefix-numeric-value arg) 0))))
(setq display-time-mode on)
(and display-time-timer (cancel-timer display-time-timer))
(setq display-time-timer nil)
(setq display-time-string "")
(or global-mode-string (setq global-mode-string '("")))
(if on
(progn
(or (memq 'display-time-string global-mode-string)
(setq global-mode-string
(append global-mode-string '(display-time-string))))
;; Set up the time timer.
(setq display-time-timer
(run-at-time t display-time-interval
'display-time-event-handler))
;; Make the time appear right away.
(display-time-update)
;; When you get new mail, clear "Mail" from the mode line.
(add-hook 'rmail-after-get-new-mail-hook
'display-time-event-handler))
(remove-hook 'rmail-after-get-new-mail-hook
'display-time-event-handler))))
(defcustom display-time-format nil
"*A string specifying the format for displaying the time in the mode line.
See the function `format-time-string' for an explanation of
how to write this string. If this is nil, the defaults
depend on `display-time-day-and-date' and `display-time-24hr-format'."
:type '(choice (const :tag "Default" nil)
string)
:group 'display-time)
(defcustom display-time-string-forms
'((if (and (not display-time-format) display-time-day-and-date)
(format-time-string "%a %b %e " now)
"")
(format-time-string (or display-time-format
(if display-time-24hr-format "%H:%M" "%-I:%M%p"))
now)
load
(if mail " Mail" ""))
"*A list of expressions governing display of the time in the mode line.
For most purposes, you can control the time format using `display-time-format'
which is a more standard interface.
This expression is a list of expressions that can involve the keywords
`load', `day', `month', and `year', `12-hours', `24-hours', `minutes',
`seconds', all numbers in string form, and `monthname', `dayname', `am-pm',
and `time-zone' all alphabetic strings, and `mail' a true/nil value.
For example, the form
'((substring year -2) \"/\" month \"/\" day
\" \" 24-hours \":\" minutes \":\" seconds
(if time-zone \" (\") time-zone (if time-zone \")\")
(if mail \" Mail\" \"\"))
would give mode line times like `94/12/30 21:07:48 (UTC)'."
:type 'sexp
:group 'display-time)
(defun display-time-event-handler ()
(display-time-update)
;; Do redisplay right now, if no input pending.
(sit-for 0)
(let* ((current (current-time))
(timer display-time-timer)
;; Compute the time when this timer will run again, next.
(next-time (timer-relative-time
(list (aref timer 1) (aref timer 2) (aref timer 3))
(* 5 (aref timer 4)) 0)))
;; If the activation time is far in the past,
;; skip executions until we reach a time in the future.
;; This avoids a long pause if Emacs has been suspended for hours.
(or (> (nth 0 next-time) (nth 0 current))
(and (= (nth 0 next-time) (nth 0 current))
(> (nth 1 next-time) (nth 1 current)))
(and (= (nth 0 next-time) (nth 0 current))
(= (nth 1 next-time) (nth 1 current))
(> (nth 2 next-time) (nth 2 current)))
(progn
(timer-set-time timer (timer-next-integral-multiple-of-time
current display-time-interval)
display-time-interval)
(timer-activate timer)))))
;; Update the display-time info for the mode line
;; but don't redisplay right now. This is used for
;; things like Rmail `g' that want to force an update
;; which can wait for the next redisplay.
(defun display-time-update ()
(let* ((now (current-time))
(time (current-time-string now))
(load (condition-case ()
(if (zerop (car (load-average))) ""
(let ((str (format " %03d" (car (load-average)))))
(concat (substring str 0 -2) "." (substring str -2))))
(error "")))
(mail-spool-file (or display-time-mail-file
(getenv "MAIL")
(concat rmail-spool-directory
(user-login-name))))
(mail (and (stringp mail-spool-file)
(or (null display-time-server-down-time)
;; If have been down for 20 min, try again.
(> (- (nth 1 (current-time))
display-time-server-down-time)
1200))
(let ((start-time (current-time)))
(prog1
(display-time-file-nonempty-p mail-spool-file)
(if (> (- (nth 1 (current-time)) (nth 1 start-time))
20)
;; Record that mail file is not accessible.
(setq display-time-server-down-time
(nth 1 (current-time)))
;; Record that mail file is accessible.
(setq display-time-server-down-time nil))))))
(24-hours (substring time 11 13))
(hour (string-to-int 24-hours))
(12-hours (int-to-string (1+ (% (+ hour 11) 12))))
(am-pm (if (>= hour 12) "pm" "am"))
(minutes (substring time 14 16))
(seconds (substring time 17 19))
(time-zone (car (cdr (current-time-zone now))))
(day (substring time 8 10))
(year (substring time 20 24))
(monthname (substring time 4 7))
(month
(cdr
(assoc
monthname
'(("Jan" . "1") ("Feb" . "2") ("Mar" . "3") ("Apr" . "4")
("May" . "5") ("Jun" . "6") ("Jul" . "7") ("Aug" . "8")
("Sep" . "9") ("Oct" . "10") ("Nov" . "11") ("Dec" . "12")))))
(dayname (substring time 0 3)))
(setq display-time-string
(mapconcat 'eval display-time-string-forms ""))
;; This is inside the let binding, but we are not going to document
;; what variables are available.
(run-hooks 'display-time-hook))
(force-mode-line-update))
(defun display-time-file-nonempty-p (file)
(and (file-exists-p file)
(< 0 (nth 7 (file-attributes (file-chase-links file))))))
(if display-time-mode
(display-time-mode t))
(provide 'time)
;;; time.el ends here