(require 'timer)
(defgroup battery nil
"Display battery status information."
:prefix "battery-"
:group 'hardware)
(defcustom battery-status-function
(cond ((and (eq system-type 'gnu/linux)
(file-readable-p "/proc/apm"))
'battery-linux-proc-apm))
"*Function for getting battery status information.
The function has to return an alist of conversion definitions.
Its cons cells are of the form
(CONVERSION . REPLACEMENT-TEXT)
CONVERSION is the character code of a \"conversion specification\"
introduced by a `%' character in a control string."
:type '(choice (const nil) function)
:group 'battery)
(defcustom battery-echo-area-format
(cond ((eq battery-status-function 'battery-linux-proc-apm)
"Power %L, battery %B (%p%% load, remaining time %t)"))
"*Control string formatting the string to display in the echo area.
Ordinary characters in the control string are printed as-is, while
conversion specifications introduced by a `%' character in the control
string are substituted as defined by the current value of the variable
`battery-status-function'."
:type '(choice string (const nil))
:group 'battery)
(defvar battery-mode-line-string nil
"String to display in the mode line.")
(defcustom battery-mode-line-format
(cond ((eq battery-status-function 'battery-linux-proc-apm)
" [%b%p%%]"))
"*Control string formatting the string to display in the mode line.
Ordinary characters in the control string are printed as-is, while
conversion specifications introduced by a `%' character in the control
string are substituted as defined by the current value of the variable
`battery-status-function'."
:type '(choice string (const nil))
:group 'battery)
(defcustom battery-update-interval 60
"*Seconds after which the battery status will be updated."
:type 'integer
:group 'battery)
(defvar battery-update-timer nil
"Interval timer object.")
(defun battery ()
"Display battery status information in the echo area.
The text being displayed in the echo area is controlled by the variables
`battery-echo-area-format' and `battery-status-function'."
(interactive)
(message "%s" (if (and battery-echo-area-format battery-status-function)
(battery-format battery-echo-area-format
(funcall battery-status-function))
"Battery status not available")))
(defun display-battery ()
"Display battery status information in the mode line.
The text being displayed in the mode line is controlled by the variables
`battery-mode-line-format' and `battery-status-function'.
The mode line will be updated automatically every `battery-update-interval'
seconds."
(interactive)
(setq battery-mode-line-string "")
(or global-mode-string (setq global-mode-string '("")))
(add-to-list 'global-mode-string 'battery-mode-line-string t)
(and battery-update-timer (cancel-timer battery-update-timer))
(setq battery-update-timer (run-at-time nil battery-update-interval
'battery-update-handler))
(battery-update))
(defun battery-update-handler ()
(battery-update)
(sit-for 0))
(defun battery-update ()
"Update battery status information in the mode line."
(setq battery-mode-line-string (propertize (if (and battery-mode-line-format
battery-status-function)
(battery-format
battery-mode-line-format
(funcall battery-status-function))
"")
'help-echo "Battery status information"))
(force-mode-line-update))
(defconst battery-linux-proc-apm-regexp
(concat "^\\([^ ]+\\)" " \\([^ ]+\\)" " 0x\\([0-9a-f]+\\)" " 0x\\([0-9a-f]+\\)" " 0x\\([0-9a-f]+\\)" " 0x\\([0-9a-f]+\\)" " \\(-?[0-9]+\\)%" " \\(-?[0-9]+\\)" " \\(.*\\)" "$")
"Regular expression matching contents of `/proc/apm'.")
(defun battery-linux-proc-apm ()
"Get APM status information from Linux kernel.
This function works only with the new `/proc/apm' format introduced
in Linux version 1.3.58.
The following %-sequences are provided:
%v Linux driver version
%V APM BIOS version
%I APM BIOS status (verbose)
%L AC line status (verbose)
%B Battery status (verbose)
%b Battery status, empty means high, `-' means low,
`!' means critical, and `+' means charging
%p battery load percentage
%s Remaining time in seconds
%m Remaining time in minutes
%h Remaining time in hours
%t Remaining time in the form `h:min'"
(let (driver-version bios-version bios-interface line-status
battery-status battery-status-symbol load-percentage
seconds minutes hours remaining-time buffer tem)
(unwind-protect
(save-excursion
(setq buffer (get-buffer-create " *battery*"))
(set-buffer buffer)
(erase-buffer)
(battery-insert-file-contents "/proc/apm")
(re-search-forward battery-linux-proc-apm-regexp)
(setq driver-version (match-string 1))
(setq bios-version (match-string 2))
(setq tem (battery-hex-to-int-2 (match-string 3)))
(if (not (logand tem 2))
(setq bios-interface "not supported")
(setq bios-interface "enabled")
(cond ((logand tem 16) (setq bios-interface "disabled"))
((logand tem 32) (setq bios-interface "disengaged")))
(setq tem (battery-hex-to-int-2 (match-string 4)))
(cond ((= tem 0) (setq line-status "off-line"))
((= tem 1) (setq line-status "on-line"))
((= tem 2) (setq line-status "on backup")))
(setq tem (battery-hex-to-int-2 (match-string 6)))
(if (= tem 255)
(setq battery-status "N/A")
(setq tem (battery-hex-to-int-2 (match-string 5)))
(cond ((= tem 0) (setq battery-status "high"
battery-status-symbol ""))
((= tem 1) (setq battery-status "low"
battery-status-symbol "-"))
((= tem 2) (setq battery-status "critical"
battery-status-symbol "!"))
((= tem 3) (setq battery-status "charging"
battery-status-symbol "+")))
(setq load-percentage (match-string 7))
(setq seconds (string-to-number (match-string 8)))
(and (string-equal (match-string 9) "min")
(setq seconds (* 60 seconds)))
(setq minutes (/ seconds 60)
hours (/ seconds 3600))
(setq remaining-time
(format "%d:%02d" hours (- minutes (* 60 hours))))))))
(list (cons ?v (or driver-version "N/A"))
(cons ?V (or bios-version "N/A"))
(cons ?I (or bios-interface "N/A"))
(cons ?L (or line-status "N/A"))
(cons ?B (or battery-status "N/A"))
(cons ?b (or battery-status-symbol ""))
(cons ?p (or load-percentage "N/A"))
(cons ?s (or (and seconds (number-to-string seconds)) "N/A"))
(cons ?m (or (and minutes (number-to-string minutes)) "N/A"))
(cons ?h (or (and hours (number-to-string hours)) "N/A"))
(cons ?t (or remaining-time "N/A")))))
(defun battery-format (format alist)
"Substitute %-sequences in FORMAT."
(let ((index 0)
(length (length format))
(result "")
char flag elem)
(while (< index length)
(setq char (aref format index))
(if (not flag)
(if (char-equal char ?%)
(setq flag t)
(setq result (concat result (char-to-string char))))
(cond ((char-equal char ?%)
(setq result (concat result "%")))
((setq elem (assoc char alist))
(setq result (concat result (cdr elem)))))
(setq flag nil))
(setq index (1+ index)))
(or (null flag)
(setq result (concat result "%")))
result))
(defun battery-insert-file-contents (file-name)
"Insert contents of file FILE-NAME after point.
FILE-NAME can be a non-ordinary file, for example, a named pipe.
Return t if file exists."
(let ((load-read-function 'battery-read-function)
(load-source-file-function nil)
(load-path '("."))
(load-history nil))
(save-excursion
(load file-name nil t t))))
(defun battery-read-function (&optional stream)
"Function for reading expressions from STREAM.
Value is always nil."
(let (char)
(while (not (< (setq char (get-file-char)) 0))
(insert char))))
(defconst battery-hex-map '((?0 . 0) (?1 . 1) (?2 . 2) (?3 . 3)
(?4 . 4) (?5 . 5) (?6 . 6) (?7 . 7)
(?8 . 8) (?9 . 9) (?a . 10) (?b . 11)
(?c . 12) (?d . 13) (?e . 14) (?f . 15)))
(defun battery-hex-to-int (string)
"Convert a hexadecimal number (a string) into a number."
(save-match-data
(and (string-match "^[ \t]+" string)
(setq string (substring string (match-end 0))))
(and (string-match "^0[xX]" string)
(setq string (substring string (match-end 0)))))
(battery-hex-to-int-2 string))
(defun battery-hex-to-int-2 (string)
(let ((index 0)
(length (length string))
(value 0)
(elem nil))
(while (and (< index length)
(setq elem (assoc (downcase (aref string index))
battery-hex-map)))
(setq value (+ (* 16 value) (cdr elem))
index (1+ index)))
value))
(provide 'battery)