lisp/battery.el

   1 ;;; battery.el --- display battery status information
   2
   3 ;; Copyright (C) 1997, 1998, 2000, 2001 Free Software Foundation, Inc.
   4
   5 ;; Author: Ralph Schleicher <rs@nunatak.allgaeu.org>
   6 ;; Keywords: hardware
   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 ;; There is at present only a function interpreting the new `/proc/apm'
  28 ;; file format of Linux version 1.3.58 or newer.  That is, what a lucky
  29 ;; coincidence, exactly the interface provided by the author's laptop.
  30
  31 ;;; Code:
  32
  33 (require 'timer)
  34
  35 \f
  36
  37 (defgroup battery nil
  38   "Display battery status information."
  39   :prefix "battery-"
  40   :group 'hardware)
  41
  42 (defcustom battery-status-function
  43   (cond ((and (eq system-type 'gnu/linux)
  44               (file-readable-p "/proc/apm"))
  45          'battery-linux-proc-apm))
  46   "*Function for getting battery status information.
  47 The function has to return an alist of conversion definitions.
  48 Its cons cells are of the form
  49
  50     (CONVERSION . REPLACEMENT-TEXT)
  51
  52 CONVERSION is the character code of a \"conversion specification\"
  53 introduced by a `%' character in a control string."
  54   :type '(choice (const nil) function)
  55   :group 'battery)
  56
  57 (defcustom battery-echo-area-format
  58   (cond ((eq battery-status-function 'battery-linux-proc-apm)
  59          "Power %L, battery %B (%p%% load, remaining time %t)"))
  60   "*Control string formatting the string to display in the echo area.
  61 Ordinary characters in the control string are printed as-is, while
  62 conversion specifications introduced by a `%' character in the control
  63 string are substituted as defined by the current value of the variable
  64 `battery-status-function'."
  65   :type '(choice string (const nil))
  66   :group 'battery)
  67
  68 (defvar battery-mode-line-string nil
  69   "String to display in the mode line.")
  70
  71 (defcustom battery-mode-line-format
  72   (cond ((eq battery-status-function 'battery-linux-proc-apm)
  73          " [%b%p%%]"))
  74   "*Control string formatting the string to display in the mode line.
  75 Ordinary characters in the control string are printed as-is, while
  76 conversion specifications introduced by a `%' character in the control
  77 string are substituted as defined by the current value of the variable
  78 `battery-status-function'."
  79   :type '(choice string (const nil))
  80   :group 'battery)
  81
  82 (defcustom battery-update-interval 60
  83   "*Seconds after which the battery status will be updated."
  84   :type 'integer
  85   :group 'battery)
  86
  87 (defvar battery-update-timer nil
  88   "Interval timer object.")
  89
  90 ;;;###autoload
  91 (defun battery ()
  92   "Display battery status information in the echo area.
  93 The text being displayed in the echo area is controlled by the variables
  94 `battery-echo-area-format' and `battery-status-function'."
  95   (interactive)
  96   (message "%s" (if (and battery-echo-area-format battery-status-function)
  97                     (battery-format battery-echo-area-format
  98                                     (funcall battery-status-function))
  99                   "Battery status not available")))
 100
 101 ;;;###autoload
 102 (defun display-battery ()
 103   "Display battery status information in the mode line.
 104 The text being displayed in the mode line is controlled by the variables
 105 `battery-mode-line-format' and `battery-status-function'.
 106 The mode line will be updated automatically every `battery-update-interval'
 107 seconds."
 108   (interactive)
 109   (setq battery-mode-line-string "")
 110   (or global-mode-string (setq global-mode-string '("")))
 111   (add-to-list 'global-mode-string 'battery-mode-line-string t)
 112   (and battery-update-timer (cancel-timer battery-update-timer))
 113   (setq battery-update-timer (run-at-time nil battery-update-interval
 114                                           'battery-update-handler))
 115   (battery-update))
 116
 117 (defun battery-update-handler ()
 118   (battery-update)
 119   (sit-for 0))
 120
 121 (defun battery-update ()
 122   "Update battery status information in the mode line."
 123   (setq battery-mode-line-string (propertize (if (and battery-mode-line-format
 124                                                       battery-status-function)
 125                                                  (battery-format
 126                                                   battery-mode-line-format
 127                                                   (funcall battery-status-function))
 128                                                "")
 129                                              'help-echo "Battery status information"))
 130   (force-mode-line-update))
 131
 132 \f
 133 ;;; `/proc/apm' interface for Linux.
 134
 135 (defconst battery-linux-proc-apm-regexp
 136   (concat "^\\([^ ]+\\)"                ; Driver version.
 137           " \\([^ ]+\\)"                ; APM BIOS version.
 138           " 0x\\([0-9a-f]+\\)"          ; APM BIOS flags.
 139           " 0x\\([0-9a-f]+\\)"          ; AC line status.
 140           " 0x\\([0-9a-f]+\\)"          ; Battery status.
 141           " 0x\\([0-9a-f]+\\)"          ; Battery flags.
 142           " \\(-?[0-9]+\\)%"            ; Load percentage.
 143           " \\(-?[0-9]+\\)"             ; Remaining time.
 144           " \\(.*\\)"                   ; Time unit.
 145           "$")
 146   "Regular expression matching contents of `/proc/apm'.")
 147
 148 (defun battery-linux-proc-apm ()
 149   "Get APM status information from Linux kernel.
 150 This function works only with the new `/proc/apm' format introduced
 151 in Linux version 1.3.58.
 152
 153 The following %-sequences are provided:
 154 %v Linux driver version
 155 %V APM BIOS version
 156 %I APM BIOS status (verbose)
 157 %L AC line status (verbose)
 158 %B Battery status (verbose)
 159 %b Battery status, empty means high, `-' means low,
 160    `!' means critical, and `+' means charging
 161 %p battery load percentage
 162 %s Remaining time in seconds
 163 %m Remaining time in minutes
 164 %h Remaining time in hours
 165 %t Remaining time in the form `h:min'"
 166   (let (driver-version bios-version bios-interface line-status
 167         battery-status battery-status-symbol load-percentage
 168         seconds minutes hours remaining-time buffer tem)
 169     (unwind-protect
 170         (save-excursion
 171           (setq buffer (get-buffer-create " *battery*"))
 172           (set-buffer buffer)
 173           (erase-buffer)
 174           (battery-insert-file-contents "/proc/apm")
 175           (re-search-forward battery-linux-proc-apm-regexp)
 176           (setq driver-version (match-string 1))
 177           (setq bios-version (match-string 2))
 178           (setq tem (battery-hex-to-int-2 (match-string 3)))
 179           (if (not (logand tem 2))
 180               (setq bios-interface "not supported")
 181             (setq bios-interface "enabled")
 182             (cond ((logand tem 16) (setq bios-interface "disabled"))
 183                   ((logand tem 32) (setq bios-interface "disengaged")))
 184             (setq tem (battery-hex-to-int-2 (match-string 4)))
 185             (cond ((= tem 0) (setq line-status "off-line"))
 186                   ((= tem 1) (setq line-status "on-line"))
 187                   ((= tem 2) (setq line-status "on backup")))
 188             (setq tem (battery-hex-to-int-2 (match-string 6)))
 189             (if (= tem 255)
 190                 (setq battery-status "N/A")
 191               (setq tem (battery-hex-to-int-2 (match-string 5)))
 192               (cond ((= tem 0) (setq battery-status "high"
 193                                      battery-status-symbol ""))
 194                     ((= tem 1) (setq battery-status "low"
 195                                      battery-status-symbol "-"))
 196                     ((= tem 2) (setq battery-status "critical"
 197                                      battery-status-symbol "!"))
 198                     ((= tem 3) (setq battery-status "charging"
 199                                      battery-status-symbol "+")))
 200               (setq load-percentage (match-string 7))
 201               (setq seconds (string-to-number (match-string 8)))
 202               (and (string-equal (match-string 9) "min")
 203                    (setq seconds (* 60 seconds)))
 204               (setq minutes (/ seconds 60)
 205                     hours (/ seconds 3600))
 206               (setq remaining-time
 207                     (format "%d:%02d" hours (- minutes (* 60 hours))))))))
 208     (list (cons ?v (or driver-version "N/A"))
 209           (cons ?V (or bios-version "N/A"))
 210           (cons ?I (or bios-interface "N/A"))
 211           (cons ?L (or line-status "N/A"))
 212           (cons ?B (or battery-status "N/A"))
 213           (cons ?b (or battery-status-symbol ""))
 214           (cons ?p (or load-percentage "N/A"))
 215           (cons ?s (or (and seconds (number-to-string seconds)) "N/A"))
 216           (cons ?m (or (and minutes (number-to-string minutes)) "N/A"))
 217           (cons ?h (or (and hours (number-to-string hours)) "N/A"))
 218           (cons ?t (or remaining-time "N/A")))))
 219
 220 \f
 221 ;;; Private functions.
 222
 223 (defun battery-format (format alist)
 224   "Substitute %-sequences in FORMAT."
 225   (let ((index 0)
 226         (length (length format))
 227         (result "")
 228         char flag elem)
 229     (while (< index length)
 230       (setq char (aref format index))
 231       (if (not flag)
 232           (if (char-equal char ?%)
 233               (setq flag t)
 234             (setq result (concat result (char-to-string char))))
 235         (cond ((char-equal char ?%)
 236                (setq result (concat result "%")))
 237               ((setq elem (assoc char alist))
 238                (setq result (concat result (cdr elem)))))
 239         (setq flag nil))
 240       (setq index (1+ index)))
 241     (or (null flag)
 242         (setq result (concat result "%")))
 243     result))
 244
 245 (defun battery-insert-file-contents (file-name)
 246   "Insert contents of file FILE-NAME after point.
 247 FILE-NAME can be a non-ordinary file, for example, a named pipe.
 248 Return t if file exists."
 249   (let ((load-read-function 'battery-read-function)
 250         (load-source-file-function nil)
 251         (load-path '("."))
 252         (load-history nil))
 253     (save-excursion
 254       (load file-name nil t t))))
 255
 256 (defun battery-read-function (&optional stream)
 257   "Function for reading expressions from STREAM.
 258 Value is always nil."
 259   (let (char)
 260     (while (not (< (setq char (get-file-char)) 0))
 261       (insert char))))
 262
 263 (defconst battery-hex-map '((?0 .  0) (?1 .  1) (?2 .  2) (?3 .  3)
 264                             (?4 .  4) (?5 .  5) (?6 .  6) (?7 .  7)
 265                             (?8 .  8) (?9 .  9) (?a . 10) (?b . 11)
 266                             (?c . 12) (?d . 13) (?e . 14) (?f . 15)))
 267
 268 (defun battery-hex-to-int (string)
 269   "Convert a hexadecimal number (a string) into a number."
 270   (save-match-data
 271     (and (string-match "^[ \t]+" string)
 272          (setq string (substring string (match-end 0))))
 273     (and (string-match "^0[xX]" string)
 274          (setq string (substring string (match-end 0)))))
 275   (battery-hex-to-int-2 string))
 276
 277 (defun battery-hex-to-int-2 (string)
 278   (let ((index 0)
 279         (length (length string))
 280         (value 0)
 281         (elem nil))
 282     (while (and (< index length)
 283                 (setq elem (assoc (downcase (aref string index))
 284                                   battery-hex-map)))
 285       (setq value (+ (* 16 value) (cdr elem))
 286             index (1+ index)))
 287     value))
 288
 289 \f
 290 (provide 'battery)
 291
 292 ;;; battery.el ends here