nixosTests.xfce: Add tests for screensaver (#457736)

      environment.systemPackages = [ pkgs.xfce.xfce4-whiskermenu-plugin ];

      programs.thunar.plugins = [ pkgs.xfce.thunar-archive-plugin ];

      programs.ydotool.enable = true;

    };

  enableOCR = true;

      with subtest("Check if Xfce components actually start"):

        machine.wait_for_window("xfce4-panel")

        machine.wait_for_window("Desktop")

        for i in ["xfwm4", "xfsettingsd", "xfdesktop", "xfce4-screensaver", "xfce4-notifyd", "xfconfd"]:

          machine.wait_until_succeeds(f"pgrep -f {i}")

        for i in ["xfwm4", "xfsettingsd", "xfdesktop", "xfce4-notifyd", "xfconfd"]:

          machine.wait_until_succeeds(f"pgrep {i}")

        machine.wait_until_succeeds("pgrep -xf xfce4-screensaver")

      with subtest("Open whiskermenu"):

        machine.succeed("su - ${user.name} -c 'DISPLAY=:0 ${bus} xfconf-query -c xfce4-panel -p /plugins/plugin-1 -t string -s whiskermenu -n >&2 &'")

        machine.succeed("su - ${user.name} -c 'DISPLAY=:0 xfce4-terminal >&2 &'")

        machine.wait_for_window("Terminal")

      with subtest("Lock the screen"):

        machine.succeed("su - ${user.name} -c '${bus} xflock4 >&2 &'")

        machine.wait_until_succeeds("su - ${user.name} -c '${bus} xfce4-screensaver-command -q' | grep 'The screensaver is active'")

        machine.sleep(5)

        machine.succeed("ydotool click 0xC0")

        machine.wait_for_text("${user.description}|Unlock")

        machine.screenshot("screensaver")

        machine.send_chars("${user.password}\n", delay=0.2)

        machine.wait_until_succeeds("su - ${user.name} -c '${bus} xfce4-screensaver-command -q' | grep 'The screensaver is inactive'")

        machine.sleep(2)

      with subtest("Open Thunar"):

        machine.succeed("su - ${user.name} -c 'DISPLAY=:0 thunar >&2 &'")

        machine.wait_for_window("Thunar")