Command Rhythmbox from Emacs

I might have mentioned before that I'm using GNU/Linux on all of my computers. The particular flavor is Ubuntu, although it shouldn't matter much, since I can count the graphical applications that I use at all, besides Emacs, on one hand. They are: Firefox, Evince, Rhythmbox and VLC. Of course, as most true Emacs-ers, I strive to reduce this number to zero. So I got quite excited when I saw helm-rhythmbox show up in my package list. It works great: you can play and enqueue tracks with completion without leaving Emacs. Big thanks to @mrBliss, and, of course, the authors for dbus.el which makes interaction with D-Bus possible through Elisp.

I'm not as big a fan of Helm as I used to be, so I quickly implemented an Ivy equivalent:

(defun counsel-rhythmbox-enqueue-song (song)
  "Let Rhythmbox enqueue SONG."
  (let ((service "org.gnome.Rhythmbox3")
        (path "/org/gnome/Rhythmbox3/PlayQueue")
        (interface "org.gnome.Rhythmbox3.PlayQueue"))
    (dbus-call-method :session service path interface
                      "AddToQueue" (rhythmbox-song-uri song))))

;;;###autoload
(defun counsel-rhythmbox ()
  "Choose a song from the Rhythmbox library to play or enqueue."
  (interactive)
  (unless (require 'helm-rhythmbox nil t)
    (error "Please install `helm-rhythmbox'"))
  (unless rhythmbox-library
    (rhythmbox-load-library)
    (while (null rhythmbox-library)
      (sit-for 0.1)))
  (ivy-read "Rhythmbox: "
            (helm-rhythmbox-candidates)
            :action
            '(1
              ("Play song" helm-rhythmbox-play-song)
              ("Enqueue song" counsel-rhythmbox-enqueue-song))))

I listed the whole code just to show how easy it is to interact with D-Bus, and also to show-off the shiny new multi-action interface of ivy-read. Besides being discoverable via C-o, the multi-action interface is extensible as well. Here's how to add a "Dequeue" action without touching the original code:

(defun counsel-rhythmbox-dequeue-song (song)
  "Let Rhythmbox dequeue SONG."
  (let ((service "org.gnome.Rhythmbox3")
        (path "/org/gnome/Rhythmbox3/PlayQueue")
        (interface "org.gnome.Rhythmbox3.PlayQueue"))
    (dbus-call-method :session service path interface
                      "RemoveFromQueue" (rhythmbox-song-uri song))))
(ivy-set-actions
 'counsel-rhythmbox
 '(("Dequeue song" counsel-rhythmbox-dequeue-song)))

Very simple, counsel-rhythmbox-dequeue-song is a clone of counsel-rhythmbox-enqueue-song with only the method change from AddToQueue to RemoveFromQueue (I blind-guessed the name, but there should be a reference somewhere). If you got tired of having a whole three actions to choose from, you can revert to the initial two with:

(ivy-set-actions 'counsel-rhythmbox nil)

And here's how the updated C-o option panel now looks like:

A bit of descriptions:

• j moves to the next one of the 18 current candidates.
• k moves to the previous candidate.
• h moves to the first candidate.
• l moves to the last candidate.
• g calls the current action without exiting.
• d calls the current action and exits.
• s moves to the next action.
• w moves to the previous action.
• i and C-o close the options panel without exiting.
• o closes the panel and exits.

Similarly to hydra, each action has a short docstring, like "Play song" that should describe what it does. Here are a few usage scenarios:

• If I wanted to play the first song and enqueue the third and the sixth and exit the minibuffer, I would press gsjjgjjjd.
• If I wanted to play the third and enqueue all the following, I would press jjgsjcjjjjjjjjjjjo. The many j is just me holding j until the selection reaches the end, then I simply exit without doing anything else by pressing o. The way c works is that it toggles the "calling" state - a state where the current action is called whenever a different candidate is selected.

Almost forgot, if this little intro got you excited, the packages that you should install from MELPA are: helm-rhythmbox and counsel.