sway: add OSD to the pactl volume control bindings

scripts/notify-volume

@@ -0,0 +1,32 @@
+#!/bin/sh
+
+set -ex
+
+if ! command -v notify-send >/dev/null || ! command -v pactl > /dev/null; then
+    exit 0;
+fi
+
+# pactl output depends on the current locale
+export LANG=C.UTF-8 LC_ALL=C.UTF-8
+
+SINK=${1:-@DEFAULT_SINK@}
+VOLUME=$(pactl get-sink-volume "$SINK")
+# get first percent value
+VOLUME=${VOLUME%%%*}
+VOLUME=${VOLUME##* }
+
+TEXT="Volume: ${VOLUME}%"
+case $(pactl get-sink-mute "$SINK") in
+    *yes)
+        TEXT="Volume: muted"
+        VOLUME=0
+        ;;
+esac
+
+notify-send \
+    --app-name sway \
+    --expire-time 800 \
+    --hint string:x-canonical-private-synchronous:volume \
+    --hint "int:value:$VOLUME" \
+    --transient \
+    "${TEXT}"