;;; echotime.el --- time, date, and battery info in Emacs echo area

;; Copyright (C) 2009 Neil Van Dyke
;;
;; Author:   Neil Van Dyke <neil AT neilvandyke DOT org>
;; Version:  1.0
;; Date:     2009-10-25
;; Keywords: time
;; Web:      http://www.neilvandyke.org/echotime-emacs/
;; CVS:      $Id: echotime.el,v 1.8 2009/10/25 14:09:19 neilpair Exp $

;; This file is NOT part of GNU Emacs.
;;
;; This 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 3 of the License, or (at your option) any later
;; version.
;;
;; This 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.  If not, see <http://www.gnu.org/licenses/>.

;;; Commentary:

;;; `echotime' is a small Emacs function that will display the date, time of
;;; day, and battery information in the echo area, on command.  Both local time
;;; and UTC time are displayed.
;;;
;;; I bind it to a key sequence, like so:
;;;
;;; (global-set-key "\C-ct" 'echotime)
;;;
;;; I wrote `echotime' a long time ago, when spending most of my time shuffling
;;; around town, trying to find power for my little old laptop, and conserving
;;; power by not running much other than Emacs.  I'm releasing it because I
;;; still find it a convenient way to check this information.

;;; Code:

(require 'battery nil t)

(defun echotime ()
  (interactive)
  (let* ((time  (current-time))
         (fg    "black")
         (bg    "gray90")
         (dim   "gray60")
         (t-str (propertize "T"   'face `(:foreground ,dim
                                                      :background ,bg)))
         (space1 (propertize " " 'face `(:foreground ,dim
                                                      :background ,bg)))
         (space3 (propertize "   " 'face `(:foreground ,dim
                                                      :background ,bg))))
    ;; TODO: Generalize redundant code for time formatting.
    (message
     "%s%s%s"
     (concat space1
             (propertize (format-time-string "%a " time)
                         'face `(:weight bold
                                         :foreground ,fg
                                         :background ,bg
                                         ))
             (propertize (format-time-string "%Y-" time)
                         'face `(:foreground ,fg
                                             :background ,bg
                                             ))
             (propertize (format-time-string "%m-%d" time)
                         'face `(:weight bold
                                         :foreground ,fg
                                         :background ,bg
                                         ))
             t-str
             (propertize (format-time-string "%H:%M"       time)
                         'face `(:weight bold
                                         :foreground "black"
                                         :background "yellow"))
             (propertize (format-time-string ":%S"       time)
                         'face `(:foreground "black"
                                             :background ,bg
                                             ))
             (propertize (format-time-string "%z" time)
                         'face `(:foreground "gray40"
                                             :background ,bg)))
     (if (member (nth 1 (current-time-zone time)) '("UTC" "GMT"))
         ""
       (concat space3
               (propertize (format-time-string "%Y-" time t)
                           'face `(:foreground ,fg
                                               :background ,bg))
               (propertize (format-time-string "%m-%d" time t)
                           'face `(
                                   :foreground ,fg
                                               :background ,bg))
               t-str
               (propertize (format-time-string "%H:%M"       time t)
                           'face `(:weight bold
                                           :foreground ,fg
                                           :background ,bg
                                           ))
               (propertize (format-time-string ":%S"       time t)
                           'face `(:foreground ,fg
                                               :background ,bg))
               (propertize "Z" 'face `(:foreground ,dim
                                                   :background ,bg))))
     (if (featurep 'battery)
         (let* ((bat     (funcall battery-status-function))
                (onlinep (member (battery-format "%L" bat) '("AC" "on-line"))))
           (concat space3
                   (if onlinep
                       (concat
                        (propertize " AC-Line "
                                    'face
                                    '(:weight bold :foreground "white"
                                              :background "green4"))
                        space1)
                     (concat
                      (propertize " Battery "
                                  'face
                                  '(:weight bold :foreground "white"
                                            :background "orange"))
                      space1))
                   (propertize (battery-format "%p%% %t" bat)
                               'face `(:foreground ,fg
                                                   :background ,bg))
                   space1))
       (concat space3
               (propertize " Power "
                           'face
                           '(:weight bold :foreground "white"
                                     :background "blue"))
               space1)))))

(provide 'echotime)

;;; echotime.el ends here