Functional programming & distributed systems blog

Yuriy Netesov on programming and stuff

Notifications from emacs(erc, compilation) in stumpwm

Intro

I have using stumpwm for 2 years now and I like it a lot.
This is a great tiled WM which is ideal for emacs users due to the same keybindgins idealogy.
One day I decided to use emacs irc client and to solve context switch issues by notifications.

Stumpwm and emacs integration

We can send commands to stumpwm via swank + slime.
Swank is like rpc server for lisp. And slime is client for swank for emacs.
In your .stumpwmrc you have to start the swank.

(load "/usr/share/common-lisp/source/slime/swank-loader.lisp")
(swank-loader:init)
(swank:create-server :port 4005
                     :style :spawn
                     :dont-close t)

Now you can command your emacs to connect to it through slime

M-x slime-connect

All lisp code you will enter in appeared REPL will be executed inside of stumpwm process.

Notifications

Stumpwm have a message command to display a message in a corner of your screen.
So all we need is to send the code like

(stumpwm:message "something happened")

into the stumpwm process. I have implemented a small module for mine config.
Here it is

(require 'slime)

(defvar de-notifications-enabled 1 "notifications switcher")

(defun de-notify-init ()
  (slime-connect "127.0.0.1" 4005))

(defun de-enable-notifications ()
  (setq de-notifications-enabled 1))

(defun de-disable-notifications ()
  (setq de-notifications-enabled 0))

(defun de-notify (origin message)
  (when (eq de-notifications-enabled 1)
    (slime-eval `(stumpwm:message 
                  (common-lisp:concatenate 'common-lisp:string "[" ,origin "] :: " ,message)))))

(de-notify-init)
(de-enable-notifications)
(de-notify "emacs" "notifications system started up")

(provide 'de-notifications)

ERC

For irc I have use following piece of code

(require 'de-notifications)
(de-notify-init)

(defun bytes-to-string (bytes)
  (apply 'concat (mapcar `byte-to-string bytes)))

(defun erc-global-notify (match-type nick message)
  (de-notify "erc" (concat "[" nick "]" ": " (bytes-to-string message))))

(add-hook 'erc-text-matched-hook 'erc-global-notify)

(de-notify "erc" "initialized erc notifications system")

(provide 'de-chat)

Compilation finished

(require 'de-notifications)
(de-notify-init)
(defun compilation-finished-hook (buf status)
  (de-notify "emacs" (concat "compilation finished with status: " status)))
(add-hook 'compilation-finish-functions #'compilation-finished-hook)