Ability to view the battery charge of connected Bluetooth devices

README.md

@@ -134,6 +134,25 @@ Options:
         can specify what timeout to use to control the responsiveness, in
         seconds.
         Default: "0.05"
+  --icons-bluetooth-battery <icon>[,<icon>...]
+        Icons for battery level of connected bluetooth headphones.
+        If no icons are provided, the feature is disabled.
+        Requires bluez experimental features to be enabled.
+        For details, see:
+          https://wiki.archlinux.org/title/Bluetooth_headset
+        Default: none
+  --hide-bluetooth-battery-level
+        Hide the integer battery level representation.
+        Requires bluez experimental features to be enabled.
+        For details, see:
+          https://wiki.archlinux.org/title/Bluetooth_headset
+        Default: none
+  --battery-max <int>
+        Set the maximum device battery level.
+        Requires bluez experimental features to be enabled.
+        For details, see:
+          https://wiki.archlinux.org/title/Bluetooth_headset
+        Default: \"$BAT_MAX\"
 
 Actions:
   help              display this message and exit

pulseaudio-control

@@ -22,11 +22,13 @@ OSD="no"
 NODE_NICKNAMES_PROP=
 VOLUME_STEP=2
 VOLUME_MAX=130
+BAT_MAX=100
 LISTEN_TIMEOUT=0.05
 # shellcheck disable=SC2016
 FORMAT='$VOL_ICON ${VOL_LEVEL}%  $ICON_NODE $NODE_NICKNAME'
 declare -A NODE_NICKNAMES
 declare -a ICONS_VOLUME
+declare -a ICONS_BLUETOOTH_BATTERY
 declare -a NODE_BLACKLIST
 
 # Special variable: within the script, pactl, grep, and awk commands are used
@@ -46,6 +48,8 @@ SINK_OR_SOURCE="ink"
 # Environment & global constants for the script
 export LC_ALL=C  # Some calls depend on English outputs of pactl
 END_COLOR="%{F-}"  # For Polybar colors
+BLUETOOTH_CONFIG="/etc/bluetooth/main.conf" # For Bluetooth configuration file
+BLUETOOTH_EXPERIMENTAL_REGEX="^Experimental = true" # Regex to tell whether battery level can be fetched
 
 
 # Saves the currently default node into a variable named `curNode`. It will
@@ -73,6 +77,22 @@ function getNodeName() {
 }
 
 
+# Saves the current battery level of a connected Bluetooth device for the node
+# passed by parameter into a variable named `BAT_LEVEL`.
+# If a node is not a Bluetooth device, `BAT_LEVEL` would be an empty string.
+# Requires bluez experimental features to be enabled.
+# For details, see: https://wiki.archlinux.org/title/Bluetooth_headset
+function getCurCharge() {
+    local bluetoothIsExperimental=$(grep -Eo "$BLUETOOTH_EXPERIMENTAL_REGEX" "$BLUETOOTH_CONFIG")
+    if [ "$bluetoothIsExperimental" ]; then
+        getNodeName "$1"
+
+        local bluetoothDeviceMac=$(echo "$nodeName" | sed -e 's/^[a-z_]*\.//' -e 's/\..*$//' | tr '_' ':')
+        BAT_LEVEL=$(bluetoothctl info "$bluetoothDeviceMac" | grep Battery | sed -E 's/.*\((.*)\)/\1/')
+    fi
+}
+
+
 # Saves the name to be displayed for the node passed by parameter into a
 # variable called `NODE_NICKNAME`.
 # If a mapping for the node name exists, that is used. Otherwise, the string
@@ -195,9 +215,9 @@ function volSync() {
         echo "PulseAudio not running"
         return 1
     fi
-    
+
     getCurVol "$curNode"
-    
+
     if [[ "$NODE_TYPE" = "output" ]]; then
         getSinkInputs "$curNode"
 
@@ -382,19 +402,38 @@ function output() {
     fi
 
     getNickname "$curNode"
+    getCurCharge "$curNode"
+
+    local iconsLen=${#ICONS_BLUETOOTH_BATTERY[@]}
+    if [ "$iconsLen" -ne 0 ] && [ "$BAT_LEVEL" != "" ]; then
+        local batSplit=$((BAT_MAX / iconsLen))
+        for i in $(seq 1 "$iconsLen"); do
+            if [ $((i * batSplit)) -ge "$BAT_LEVEL" ]; then
+                BAT_ICON="${ICONS_BLUETOOTH_BATTERY[$((i-1))]}"
+                break
+            fi
+        done
+
+        BLUETOOTH_FORMAT='$BAT_ICON ${BAT_LEVEL}%'
+        if [ "$HIDE_BAT" = "yes" ] && [ "$BAT_LEVEL" != '' ]; then
+            BLUETOOTH_FORMAT='$BAT_ICON'
+        fi
+    else
+        BLUETOOTH_FORMAT=''
+    fi
 
     # Showing the formatted message
     if [ "$IS_MUTED" = "yes" ]; then
         # shellcheck disable=SC2034
         VOL_ICON=$ICON_MUTED
-        content="$(eval echo "$FORMAT")"
+        content="$(eval echo "$FORMAT"  "$BLUETOOTH_FORMAT")"
         if [ -n "$COLOR_MUTED" ]; then
             echo "${COLOR_MUTED}${content}${END_COLOR}"
         else
             echo "$content"
         fi
     else
-        eval echo "$FORMAT"
+        eval echo "$FORMAT"  "$BLUETOOTH_FORMAT"
     fi
 }
 
@@ -484,6 +523,25 @@ Options:
         can specify what timeout to use to control the responsiveness, in
         seconds.
         Default: \"$LISTEN_TIMEOUT\"
+  --icons-bluetooth-battery <icon>[,<icon>...]
+        Icons for battery level of connected bluetooth headphones.
+        If no icons are provided, the feature is disabled.
+        Requires bluez experimental features to be enabled.
+        For details, see:
+          https://wiki.archlinux.org/title/Bluetooth_headset
+        Default: none
+  --hide-bluetooth-battery-level
+        Hide the integer battery level representation.
+        Requires bluez experimental features to be enabled.
+        For details, see:
+          https://wiki.archlinux.org/title/Bluetooth_headset
+        Default: none
+  --battery-max <int>
+        Set the maximum device battery level.
+        Requires bluez experimental features to be enabled.
+        For details, see:
+          https://wiki.archlinux.org/title/Bluetooth_headset
+        Default: \"$BAT_MAX\"
 
 Actions:
   help              display this message and exit
@@ -551,6 +609,17 @@ while [[ "$1" = --* ]]; do
             # shellcheck disable=SC2034
             ICON_NODE="$val"
             ;;
+        --hide-bluetooth-battery-level)
+            HIDE_BAT=yes
+            ;;
+        --icons-bluetooth-battery)
+            if getOptVal "$@"; then shift; fi
+            IFS=, read -r -a ICONS_BLUETOOTH_BATTERY <<< "${val//[[:space:]]/}"
+            ;;
+        --battery-max)
+            if getOptVal "$@"; then shift; fi
+            BAT_MAX="$val"
+            ;;
         --icons-volume)
             if getOptVal "$@"; then shift; fi
             IFS=, read -r -a ICONS_VOLUME <<< "${val//[[:space:]]/}"

tests.bats

@@ -1,8 +1,8 @@
 #!/usr/bin/env bats
 # vim: filetype=sh
-# 
+#
 # Polybar PulseAudio Control - tests.bats
-# 
+#
 # Simple test script to make sure the most basic functions in this script
 # always work as intended. The tests will modify the system's PulseAudio
 # setup until it's restarted, so either do that after running the test, or
@@ -31,6 +31,10 @@ function setup() {
     restartPulseaudio
     echo "Loading script"
     source pulseaudio-control.bash output &>/dev/null
+
+    # In case there's a Bluetooth device connected, 3 seconds are well enough
+    # to reestalish the connection after restarting PulseAudio.
+    sleep 3
 }
 
 
@@ -194,3 +198,19 @@ function setup() {
     getNickname "$((10 + offset))" # beyond what exists
     [ "$NODE_NICKNAME" = "Sink #$((10 + offset))" ]
 }
+
+
+@test "getCurCharge()" {
+    getCurNode
+    getCurCharge "$curNode"
+
+    local bluetoothIsExperimental=$(grep -Eo "$BLUETOOTH_EXPERIMENTAL_REGEX" "$BLUETOOTH_CONFIG")
+    local bluetoothDeviceMac=$(echo "$nodeName" | sed -e 's/^[a-z_]*\.//' -e 's/\..*$//' | tr '_' ':')
+
+    if [ "$bluetoothIsExperimental" ] && [ "$bluetoothDeviceMac" ]; then
+        local expectedBatLevel=$(bluetoothctl info "$bluetoothDeviceMac" | grep Battery | sed -E 's/.*\((.*)\)/\1/')
+        [ "$BAT_LEVEL" == "$expectedBatLevel" ]
+    else
+        [ "$BAT_LEVEL" == '' ]
+    fi
+}