使用 python 3 检测 Ubuntu 20.04.6 中的 PowerSaveMode 或屏幕保护程序状态

Question

当屏幕变黑时如何监控 dbus 消息？

以下是 dbus-monitor 的输出

signal time=1699887162.074353 sender=:1.12288 -> destination=(null destination) serial=2006 path=/org/gnome/Mutter/DisplayConfig; interface=org.freedesktop.DBus.Properties; member=PropertiesChanged
   string "org.gnome.Mutter.DisplayConfig"
   array [
      dict entry(
         string "PowerSaveMode"
         variant             int32 3
      )
   ]
   array [
   ]

和

signal time=1699887179.300585 sender=:1.12288 -> destination=(null destination) serial=2009 path=/org/gnome/Mutter/DisplayConfig; interface=org.freedesktop.DBus.Properties; member=PropertiesChanged
   string "org.gnome.Mutter.DisplayConfig"
   array [
      dict entry(
         string "PowerSaveMode"
         variant             int32 0
      )
   ]
   array [
   ]