Function: rxvt-colorfgbg-background-mode

rxvt-colorfgbg-background-mode is a byte-compiled function defined in rxvt.el.gz.

Signature

(rxvt-colorfgbg-background-mode FGBG)

Documentation

Determine background mode.

FGBG is a string of the same meaning as the COLORFGBG environment variable.

Source Code

;; Defined in /usr/src/emacs/lisp/term/rxvt.el.gz
(defun rxvt-colorfgbg-background-mode (fgbg)
  "Determine background mode.
FGBG is a string of the same meaning as the COLORFGBG environment variable."
  (let (bg rgb)
    (when (and fgbg
	       (string-match ".*;\\([0-9][0-9]?\\)\\'" fgbg))
      (setq bg (string-to-number (substring fgbg (match-beginning 1))))
      ;; The next line assumes that rxvt-standard-colors are ordered
      ;; by the color index in the ascending order!
      (setq rgb (car (cddr (nth bg rxvt-standard-colors))))
      ;; See the commentary in frame-set-background-mode about the
      ;; computation below.
      (if (< (apply '+ rgb)
	     ;; The following line assumes that white is the 15th
	     ;; color in rxvt-standard-colors.
	     (* (apply '+ (car (cddr (nth 15 rxvt-standard-colors)))) 0.6))
          'dark
        'light))))