waybar: added pipewire listener for displaying audio status changes in real time

.config/river/init

@@ -201,6 +201,9 @@ riverctl spawn "wlclock --layer background --background-colour '#00000000' --clo
 #riverctl spawn "$HOME/.config/river/bar"
 riverctl spawn waybar
 
+# Start waybar audio listener
+~/.local/bin/waybar_audio_event_bridge.sh &
+
 # Idle configuration
 riverctl spawn "swayidle -w timeout 1200 'wlopm --off \"*\"' resume 'wlopm --on \"*\"' before-sleep 'waylock -fork-on-lock'"
 

.config/waybar/config.jsonc

@@ -71,6 +71,7 @@
 
 	"custom/audio": {
 		"exec": "~/.local/bin/waybar_audio.sh",
+		"signal": 8,
 		"return-type": "json",
 		"format": "{icon} {text}",
 		"format-icons": {

.local/bin/waybar_audio_event_bridge.sh

@@ -0,0 +1,26 @@
+#!/usr/bin/env bash
+set -euo pipefail
+SIG=8
+
+get_waybar_pid() { pgrep -u "$USER" -x waybar | head -n1 || true; }
+log() { echo "[waybar-audio-bridge] $*" >&2; }
+
+WAYBAR_PID=""
+while [[ -z "$WAYBAR_PID" ]]; do
+  WAYBAR_PID="$(get_waybar_pid)"
+  sleep 1
+done
+log "connected to Waybar PID $WAYBAR_PID"
+
+# read pw-mon output, but only care about Audio nodes
+pw-mon 2>/dev/null | grep --line-buffered -E "Audio|Sink|Source|Stream|Node" | while read -r _; do
+  # small debounce to avoid spamming CPU when multiple updates arrive fast
+  sleep 0.2
+  if ! kill -0 "$WAYBAR_PID" 2>/dev/null; then
+    WAYBAR_PID="$(get_waybar_pid)"
+    [[ -z "$WAYBAR_PID" ]] && continue
+    log "reconnected to Waybar PID $WAYBAR_PID"
+  fi
+  kill -RTMIN+"$SIG" "$WAYBAR_PID" 2>/dev/null || true
+done
+