Awesome
Polybar Spotify Module
This is a pure C implementation of an external polybar module that signals polybar when a track is playing/paused and when the track changes. There is also a program that retreives the title and artist of the currently playing song on spotify.
Requirements
DBus is used for listening to spotify track changes. Obviously you need spotify
and polybar as well:
dbus polybar spotify
To compile the program, you will need make
.
You most likely already have the above packages installed. Systemd depends on DBus, and you wouldn't be looking at this, if you didn't have polybar and spotify installed.
How to Setup
Installing the Program
Run the following code to clone the repo and install the programs.
git clone https://github.com/mihirlad55/polybar-spotify-module
cd polybar-spotify-module/src/
sudo make install
Arch Linux Users
polybar-spotify-module
exists as a package on the AUR! Use your favourite
AUR helper to install the package.
yay -S polybar-spotify-module
The package can be found here https://aur.archlinux.org/packages/polybar-spotify-module/.
Running spotify-listener in the Background
spotify-listener
must run in the background for it to be able to listen for
track changes and communicate with polybar. There are two ways to keep it
running in the background. If you are using systemd, you can have it start at
system startup by running:
systemctl --user enable spotify-listener
Then, you can start the service now by running:
systemctl --user start spotify-listener
If you are not using systemd, make sure the spotify-listener
program is
executed at startup. Something like
spotify-listener &
disown
in a startup script should accomplish that.
Configuring Polybar
Your polybar configuration file should be located at .config/polybar/config
First make sure IPC is enabled. The following should be in your configuration
file under the [bar/<your bar name>]
section:
[bar/main]
enable-ipc = true
If you plan to use icons for next/play/previous/pause buttons, make sure you
add (and have installed) an icon font accordingly such as NerdFonts or
FontAwesome under the [bar/<your bar name>]
section:
[bar/main]
font-1 = Font Awesome 5 Free:size=10;1
Note that the font is specified in modules as a 1-based index, so font-1
is
specified by format-font = 2
.
Next, add the following spotify modules:
[module/previous]
type = custom/ipc
format-font = 2
; Default
hook-0 = echo ""
; When spotify active
hook-1 = echo "Previous"
click-left = "spotifyctl -q previous"
[module/next]
type = custom/ipc
format-font = 2
; Default
hook-0 = echo ""
; When spotify active
hook-1 = echo "Next"
click-left = "spotifyctl -q next"
[module/playpause]
type = custom/ipc
format-font = 2
; Default
hook-0 = echo ""
; Playing
hook-1 = echo "Pause"
; Paused
hook-2 = echo "Play"
click-left = "spotifyctl -q playpause"
[module/spotify]
type = custom/ipc
; Default
hook-0 = echo ""
; Playing/paused show song name and artist
hook-1 = spotifyctl -q status --format '%artist%: %title%'
You can replace the text for Pause/Play/Next/Previous with icons for each of the hooks.
Lastly, make sure the new spotify modules are part of your bar. Make sure one of the following lines is part of your modules.
modules-center = spotify previous playpause next
modules-left = spotify previous playpause next
modules-right = spotify previous playpause next
Status Formatting
The spotifyctl status
command has multiple formatting options. You can
specify the:
- Maximum output length
- Maximum artist length
- Maxiumum track title length
- Output Format
- Truncation string
By default, the above lengths are INT_MAX
(no limit). Additionally, if max
length is specified, the artist and track title will not be truncated if
the untruncated output satisfies the output max length constraint.
The tokens %artist%
and %title%
can be used to specify the output format.
For example for the artist Eminem
and track title Sing For The Moment
spotifyctl status --format '%artist%: %title%' --max-length 20 \
--max-title-length 10 --max-artist-length 10 --trunc '...'
would result in the following output
Eminem: Sing Fo...
For more information and examples, you can run the command spotifyctl help
.
How it Works
The spotify-listener program connects to the DBus Session Bus and listens for two particular signals:
org.freedesktop.DBus.ProprtyChanged
for track changesorg.freedesktop.DBus.NameOwnerChanged
for spotify disconnections
Using this information, it sends messages to spotify polybar custom/IPC modules to show/hide spotify controls and display the play/pause icon based on whether a song is playing/paused.
The spotifyctl program calls org.mpris.MediaPlayer2.Properties.Get
method to
retreive status information and calls methods in the
org.mpris.MediaPlayer2.Player
interface to pause/play and go to the
previous/next track.
Why Did I Make this in C
- Practice/learn low-level C
- Reduce number of dependencies
- Make something as lightweight as possible by directly interfacing with DBus
- For fun 😜
Resources
The following are very useful resources for DBus API and specs:
- https://dbus.freedesktop.org/doc/api/html/group__DBusConnection.html
- https://dbus.freedesktop.org/doc/api/html/group__DBusBus.html
- https://dbus.freedesktop.org/doc/api/html/group__DBusMessage.html
- https://dbus.freedesktop.org/doc/dbus-specification.html
- https://dbus.freedesktop.org/doc/dbus-tutorial.html
Credits
Inspired by the python implementation by dietervanhoof: https://github.com/dietervanhoof/polybar-spotify-controls