my-emacs-d/lisp/nyan-prompt/nyan-prompt.el

;;; nyan-prompt.el --- Nyan Cat on the eshell prompt.

;; Author: Javier "PuercoPop" Olaechea <pirata@gmail.com>
;; URL: http://github.com/PuercoPop/nyan-prompt
;; Version: 0.2.0
;; Keywords: nyan, cat, lulz, eshell, rainbow
;; Dependencies ((rx 0))

;;; Commentary:

;; Usage: (add-hook 'eshell-load-hook 'nyan-prompt-enable)

;; Inspired by from Jacek "TeMPOraL" Zlydach nyan-mode, to make Porter happy.


;; Copying is an act of love, please copy.  ♡
;; The xpm taken awesome nyan-mode

;;; Code:

(require 'rx)

(defconst nyan-prompt-dir (file-name-directory
                             (or load-file-name buffer-file-name)))

(defconst nyan-prompt-nyan-cat-image
  (create-image (concat nyan-prompt-dir "img/nyan.xpm")
                'xpm nil :ascent 'center))

(defconst nyan-prompt-nyan-cat-emoticon "~=[,,_,,]:3"
  "ASCII art representing the nyan-cat.")

(defconst nyan-prompt-nyan-cat-string
  (propertize nyan-prompt-nyan-cat-emoticon
              'display nyan-prompt-nyan-cat-image))

(defvar nyan-prompt-original-prompt nil
  "The eshell prompt function before enabling nyan-prompt")

(defvar nyan-prompt-enabled nil
  "t if nyan-prompt is enabled")

(defun eshell-nyan-prompt ()
  (concat nyan-prompt-nyan-cat-string " " (funcall nyan-prompt-original-prompt)))

(defun nyan-prompt-disable ()
  (when nyan-prompt-enabled
    (setq nyan-prompt-enabled nil
          eshell-prompt-function nyan-prompt-original-prompt)))

;;;###autoload
(defun nyan-prompt-enable ()
  (when (not nyan-prompt-enabled)
    (setq nyan-prompt-enabled t
          nyan-prompt-original-prompt eshell-prompt-function
          eshell-prompt-function 'eshell-nyan-prompt)))


(provide 'nyan-prompt)
;;; nyan-prompt.el ends here