Using Emacs as system-wide Rhythmbox interface

In an earlier post, I described how I've been managing Rhythmbox from Emacs. I've bound the entry point to C-S-o:

(global-set-key (kbd "C-S-o") 'counsel-rhythmbox)

Obviously, this entry point won't work while outside Emacs. Today, I'll describe how I've made it work everywhere. Everywhere on Ubuntu 14.04, that is, although a similar approach should work for other distributions.

Step 1: Make sure the Emacs server is running

Here's the relevant part of my init.el:

(require 'server)
(or (server-running-p) (server-start))

Using emacsclient is essential to avoiding the extra startup time: even a startup time of one second feels sluggish when all I need is to open a menu with a song playlist.

Step 2: Install the relevant X window tool

Initially, I only wrote a call to emacsclient, which resulted in the Emacs window gaining focus in the end. Then I thought it would be nice to give the focus back the original window after the end of selection, and raise it as well.

I wanted to do something with wmctrl, but I found that xdotool can do what I want in a simple way.

sudo apt-get install xdotool

Step 3: Write a shell script

#!/bin/bash
wnd_id="$(xdotool getwindowfocus)"
emacsclient --eval "(progn (x-focus-frame nil) (counsel-rhythmbox))"
xdotool windowfocus $wnd_id
xdotool windowraise $wnd_id

Here, (x-focus-frame nil) will raise the Emacs window and give the keyboard input focus. emacsclient will return as soon as I select something or press C-g. At that point the keyboard focus will be returned to whatever window had it when the script was invoked.

By the way, here's a cool configuration that automatically makes a file executable if it starts with #!.

(add-hook
 'after-save-hook
 'executable-make-buffer-file-executable-if-script-p)

Step 4: Bind the shell script to a key

Open this (possibly using gnome-control-center instead, if applicable):

unity-control-center keyboard

And add a new shortcut in Shortcuts/Custom Shortcuts. I've bound that one to C-S-o as well.

The final result

It's pretty convenient: as I'm scrolling something I'm reading in Firefox with j (via Firemacs), I can seamlessly press C-S-o moo RET to play "Sisters of the Moon", and continue scrolling the web page with j.

What's more, Emacs has very nice support for input methods with C-\ (toggle-input-method), so I can also quickly select Ukrainian-titled songs, while still keeping shortcuts like C-n and C-m (without having to switch the input method back).

The whole experience is similar to gnome-do/synapse, which I was using a few years back, except better because now it's in Emacs.