Volnoti

Volnoti is, according to its own GitHub page,

"A lightweight volume notification daemon for GNU/Linux and other POSIX operating systems. It is based on GTK and D-Bus and should work with any sensible window manager. The original aim was to create a volume notification daemon for lightweight window managers like LXDE or XMonad. It is known to work with a wide range of WMs, including GNOME, KDE, Xfce, LXDE, XMonad, i3 and many others."

Volnoti can be useful to check volume changes if you are running a lightweight window manager like Openbox, which does not usually come with a notification daemon, especially in combination with your laptop/keyboard's special keys.

Installation

Install the volnoti^AUR package from AUR.

Usage and configuration

Starting Volnoti

To start the daemon, run the command

$ volnoti

Volnoti will run in background. In order to have Volnoti run automatically when your window manager starts, add the command to your WM's autostart file (e.g. ~/.config/openbox/autostart if you are using Openbox). Check the program is running by typing in your terminal emulator

$ volnoti-show 20

A semi-transparent square should appear at the centre of your screen, showing a volume of 25%. Now you should configure Volnoti to display a notification each time your volume is changed.

Configuration with Xbindkeys

The configuration below will use Volnoti, Alsa and Xbindkeys to show the volume changes while pressing the hotkeys; this example will assume Xbindkeys has already been install and configured as described in its page.

Open ~./xbindkeysrc in a text editor and add these lines before the string # End of xbindkeys configuration:

# Increase volume
"amixer set Master 5%+ && volnoti-show $(amixer get Master | grep -Po "[0-9]+(?=%)" | tail -1)"
   XF86AudioRaiseVolume

# Decrease volume
"amixer set Master 5%- && volnoti-show $(amixer get Master | grep -Po "[0-9]+(?=%)" | tail -1)"
   XF86AudioLowerVolume

# Toggle volume
"amixer set Master toggle; if amixer get Master | grep -Fq "[off]"; then volnoti-show -m; else volnoti-show $(amixer get Master | grep -Po "[0-9]+(?=%)" | tail -1); fi"
   XF86AudioMute

The first two commands will increase or lower the volume when the corresponding special keys are pressed, reading the new volume level and sending it as an argument to volnoti-show; the third one will toggle the volume and display Volnoti's corresponding notification (according to whether the volume was muted or unmuted).

Now you can restart Xbindkeys with kill -1 $(pidof xbindkeys) (or reboot your PC, after making sure both Volnoti and Xbindkeys are in your autostart file) and test your configuration.

Configuration with i3

Add the following three lines to your i3 configuration file (~/.i3/config or ~/.config/i3/config by default)

 bindsym XF86AudioRaiseVolume exec --no-startup-id "amixer set Master 2%+ && volnoti-show $(amixer get Master | grep -Po '[0-9]+(?=%)' | head -1)"
 bindsym XF86AudioLowerVolume exec --no-startup-id "amixer set Master 2%- && volnoti-show $(amixer get Master | grep -Po '[0-9]+(?=%)' | head -1)"
 bindsym XF86AudioMute exec --no-startup-id "amixer set Master toggle && if amixer get Master | grep -Fq '[off]'; then volnoti-show -m; else volnoti-show $(amixer get Master | grep -Po '[0-9]+(?=%)' | head -1); fi"