Implement battery-mode-line-limit option.

2 files changed, 22 insertions, 9 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 3fcb5e59fc6..c7fb8fcd069 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,5 +1,8 @@
 2011-06-27  Richard Stallman  <rms@gnu.org>
 
+        * battery.el (battery-mode-line-limit): New variable.
+        (battery-update): Handle it.
+
         * mail/rmailmm.el (rmail-mime-process-multipart):
         Handle truncated messages.
 
diff --git a/lisp/battery.el b/lisp/battery.el
index 9afe9de7b98..d7d3045fa58 100644
--- a/lisp/battery.el
+++ b/lisp/battery.el
@@ -102,6 +102,11 @@ string are substituted as defined by the current value of the variable
   "String to display in the mode line.")
 ;;;###autoload (put 'battery-mode-line-string 'risky-local-variable t)
 
+(defcustom battery-mode-line-limit 100
+  "Percentage of full battery load below which display battery status"
+  :type 'integer
+  :group 'battery)
+
 (defcustom battery-mode-line-format
   (cond ((eq battery-status-function 'battery-linux-proc-acpi)
          "[%b%p%%,%d°C]")
@@ -182,16 +187,21 @@ seconds."
 
 (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"))
+  (let ((data (and battery-status-function (funcall battery-status-function))))
+    (setq battery-mode-line-string
+          (propertize (if (and battery-mode-line-format
+                               (<= (car (read-from-string (cdr (assq ?p data))))
+                                   battery-mode-line-limit))
+                          (battery-format
+                           battery-mode-line-format
+                           data)
+                        "")
+                      'face
+                      (and (<= (car (read-from-string (cdr (assq ?p data))))
+                                   battery-load-critical)
+                           'font-lock-warning-face)
+                      'help-echo "Battery status information")))
   (force-mode-line-update))
-
 
 ;;; `/proc/apm' interface for Linux.