cppbtbl (C++ bluetooth battery level)

A wrapper around UPower's DBus API that returns connected bluetooth devices' battery (and that can also be used as a waybar module!)

Installing

From the AUR

If you're using Arch Linux, you can install the package from the AUR under the cppbtbl name by using the AUR helper of your choice

Manually

First of all, you're gonna need to install sdbus-c++, see sdbus-cpp: Building and installing the library

Clone the repo

git clone https://github.com/pato05/cppbtbl
cd cppbtbl

Build using CMake

cmake .
make
sudo make install

Note

cppbtbl depends on sdbus-c++ which itself depends on libsystemd. Regardless of this dependency, though, you don't necessarily need systemd, as you can get libsystemd without having it: see sdbus-cpp: Solving libsystemd dependency.

Note that if you are using systemd, you won't have any issues using cppbtbl.

Configuration

cppbtbl supports a variety of flags, which can be seen by doing cppbtbl --help.

Each of these flags (in its long form) can be written inside a configuration file (with the format name=value) that is found inside either $XDG_CONFIG_HOME/cppbtbl/config (if defined) or $HOME/.config/cppbtbl/config.

An example of this config file can be as follows:

format=custom
output={icon} ({percentage}%)
icons=1,2,3,4,5

You can also specify the dont-follow option here (if needed) by just typing it with no following characters.

format=custom
output={icon} ({percentage}%)
icons=1,2,3,4,5
dont-follow

Waybar

...
    "custom/bt-battery": {
        "exec": "cppbtbl -f waybar",
        "restart-interval": 5,
        "return-type": "json",
        "format": "{icon}",
        "format-icons": ["󰁺", "󰁻", "󰁼", "󰁼", "󰁽", "󰁿", "󰂀", "󰂀", "󰂂", "󰁹"]
    },
...

Change format and icons accordingly, and the module should work!

Polybar

[module/bt-battery]
type = custom/script

exec = cppbtbl

; This is necessary, because cppbtbl will continue running
; so let's make sure polybar knows about it
tail = true

Now, you need to define your custom options, see #configuration. Please make sure to use --format=custom.

Other status bars

In other status bars, just like we saw in Polybar, you can use --format custom and defining your own --output-format and your --icons-set

For example cppbtbl --format custom --output "{icon} ({percentage}%)" --icons 'icon1,icon2,icon3'.

Keep in mind that by default the cppbtbl process will always be running and listening for connection/disconnection events, therefore your bar must be able to handle that. In case you want to use a "polling" approach, you can use the --dont-follow option, which will close the program once it returned the desired output.

Please note that the "polling" approach won't be closely as efficient as the "listening" one, because too high of an interval will cause massive CPU usage, too low and you'll get a delay between your device being connected and it being shown in your bar.

A thank-you goes to @Justasic for helping me a lot in making this.