schnippets/desktop/screensaver_start.sh

#!/usr/bin/env bash

# MPRIS = Media Player Remote Interfacing Specification
firefox_mpris_dbus=$(dbus-send --print-reply --dest=org.freedesktop.DBus  /org/freedesktop/DBus org.freedesktop.DBus.ListNames | grep -Po "org.mpris.*firefox[^\"]+")

if [ -n ${firefox_mpris_dbus} ]; then
  playback_string=$(dbus-send --print-reply --dest=${firefox_mpris_dbus} /org/mpris/MediaPlayer2 org.freedesktop.DBus.Properties.Get string:'org.mpris.MediaPlayer2.Player' string:'PlaybackStatus' | grep -Po "(?<=string \")[^\"]+")
fi

# Suspend Firefox processes if not playing media
if [ -z "${playback_string}" ] || [ "${playback_string}" != "Playing" ]; then
  ps aux | grep [f]irefox/[f]irefox | awk '{print $2}' | xargs -P0 -I {} kill -STOP {}
fi

# Suspend Atom processes
ps aux | grep "/[a]tom" | awk '{print $2}' | xargs -P0 -I {} kill -STOP {}