Desktop

Display Managers

Introduction

The display manager (DM) is responsible for authenticating a user and launching a desktop environment. Here are a few popular DMs available on Linux distributions [6][7]:

  • GNOME Display Manager (GDM) = Specific to the GNOME desktop environment.

  • Light Display Manager (LightDM) = Generic DM used to launch any desktop environment (including GNOME).

Automatically Login User

Here is how to automatically login a user after a given timeout. A reboot is required for these changes to take affect.

  • GDM [5]:

    $ sudo -E ${EDITOR} /etc/gdm/custom.conf

    [daemon]
AutomaticLoginEnbable=true
AutomaticLogin=<USER>
TimedLoginEnable=true
TimedLogin=<USER>
TimedLoginDelay=<SECONDS>

  • LightDM [6]:

    $ sudo groupadd --system autologin
$ gpasswd -a <USER> autologin
$ sudo -E ${EDITOR} /etc/lightdm/lightdm.conf

    [SeatDefaults]
autologin-guest = false
autlogin-user = <USER>
autologin-user-timeout = <SECONDS>

Window Managers

Window managers (WMs) control the look and feel of windows.

  • Compiz

  • FluxBox

  • Kwin

  • Muffin

  • Mutter

  • Openbox

  • Xfwm

Tiled window managers specialize in splitting up windows into tiles/boxes that can be modified with keyboard shortcuts.

  • Awesome

  • Dwm

  • i3

  • Wmii

[1]

Desktop Environments

Introduction

Desktop environments (DEs) are built on top of windows managers. They provide the full functionality of a graphical desktop by bundling applications for managing media, files, and network connections. Some DEs have created their own custom window managers as well. [1]

DE Name

Graphical Toolkit

WM

Resource Usage

Cinnamon

GTK

Muffin

Medium

GNOME

GTK

Mutter

Medium

KDE

Qt

Kwin

High

Xfce

GTK

Xfwm

Low

Cinnamon

Installation:

  • Arch Linux: $ sudo pacman -S cinnamon

  • Debian (manual): $ sudo apt-get install cinnamon

  • Debian (automatic): $ sudo apt-get install task-cinnamon-desktop

  • Fedora: $ sudo dnf groupinstall "Cinnamon Desktop"

GNOME

Installation:

  • Arch Linux: $ sudo pacman -S gnome gnome-extras

  • Debian (manual): $ sudo apt-get install gnome

  • Debian (automatic): $ sudo apt-get install task-gnome-desktop

  • Fedora: $ sudo dnf groupinstall "GNOME Desktop Environment"

The gnome-tweaks package provides access to useful advanced settings of the GNOME desktop environment via the Tweaks application.

Suggested tweaks:

  • Extensions > Applications menu > On

  • Keyboard & Mouse > Mouse > Pointer Location > On

  • Top Bar > Battery Percentage > On

  • Window Titlebars > Titlebar Buttons > [Maximize|Minimize] > On

KDE

Installation:

  • Arch Linux: $ sudo pacman -S plasma kde-applications

  • Debian (manual): $ sudo apt-get install kde-standard

  • Debian (automatic): $ sudo apt-get install task-kde-desktop

  • Fedora: $ sudo dnf groupinstall "KDE Plasma Workspaces"

Xfce

Installation:

  • Arch Linux: $ sudo pacman -S xfce4 xfce4-goodies

  • Debian (manual): $ sudo apt-get install xfce4

  • Debian (automatic): $ sudo apt-get install task-xfce-desktop

  • Fedora: $ sudo dnf groupinstall "Xfce Desktop"

Display Usage

Rotate Screen

When using Xorg, xrandr can rotate the screen. This needs to use a graphics driver that supports modesetting. Legacy drivers such as xf86-video-amdgpu, xf86-video-intel, xf86-video-nouveau, or xf86-video-vmware will not work.

  • View the list of displays. Rotate it in a specified direction.

    $ xrandr
$ xrandr --output <DISPLAY> --rotate [left|right|normal|inverted]

  • If this error occurs, then a legacy Xorg driver is installed that does not support modesetting. [4]

    xrandr: output eDP1 cannot use rotation "right" reflection "none"

Remote Access

Parsec

Parsec is a tool that can be used to remotely access macOS and Windows hosts. It supports Linux, macOS, and Windows hosts.

Virtual Monitors

Parsec requires a physical monitor to be plugged into the computer and turned on. There are a few ways to create virtual monitors so that a physical monitor is no longer required. [2]

  • Paid versions of Parsec Teams and Enterprise provide support for creating virtual monitors.

  • Hardware HDMI dummy plugs exist to fake having a monitor plugged in.

  • On Windows hosts, use the Amyuni Virtual Display Driver (usbmmid).

    • This virtual display is not persistent on reboots. Create a scheduled task to start it as the Administrator on boot.

      Task Scheduler (taskschd.msc) > Create Basic Task... > Name: Virtual Monitor > Next > When do you want the task to start? When the computer starts > Next > Start a program > Next > Program/script: (select the "usbmidd.bat" file) > Next > Finish
Task Scheduler (taskschd.msc) > Task Scheduler (Local) > Task Scheduler Library > Virtual Monitor > Properties > (select "Run whether user is logged in or not" and "Run with highest privileges") > OK

Virtual Audio

Parsec does not create any virtual audio devices. Instead, it forwards connected hardware audio from the Parsec host to the client. There are a few ways around this for a headless setup.

Image Processing

  • Remove all metadata from an image.

    $ mogrify -strip <IMAGE_FILE_NAME>

  • Compress an image to a specified size.

    $ [jpegoptim|optipng] --size=500K <IMAGE_FILE_NAME>

  • Resize an image.

    $ convert <IMAGE_ORIGINAL> -resize <PERCENTAGE>% <IMAGE_NEW>
$ convert <IMAGE_ORIGINAL> -resize <PIXELS_LENGTH>x<PIXELS_WIDTH> <IMAGE_NEW>

  • Rotate an image.

    $ convert <IMAGE_ORIGINAL> -rotate <DEGRESS> <IMAGE_NEW>

Bibliography

  1. “DesktopEnvironment.” Debian Wiki. June 7, 2018. Accessed November 26, 2018. https://wiki.debian.org/DesktopEnvironment

  2. “Remote Streaming Without a Display.” r/ParsecGaming. June 29, 2022. Accessed August 27, 2022. https://www.reddit.com/r/ParsecGaming/comments/kbzbhg/remote_streaming_without_a_display/

  3. “Unable To Hear The Game You’re Playing.” Parsec. Accessed September 6, 2022. https://support.parsec.app/hc/en-us/articles/115002700892-Unable-To-Hear-The-Game-You-re-Playing

  4. “xrandr cannot use rotation “normal” reflection “none”.” Unix & Linux Stack Exchange. August 16, 2021. Accessed February 16, 2023. https://unix.stackexchange.com/questions/636886/xrandr-cannot-use-rotation-normal-reflection-none

  5. “Configure automatic login.” GNOME Library. Accessed April 9, 2023. https://help.gnome.org/admin/system-admin-guide/stable/login-automatic.html.en

  6. “How to Login Automatically to Linux [most distros support].” FOSTips. September 2, 2022. Accessed April 9, 2023. https://fostips.com/login-automatically-linux/

  7. “Display manager.” ArchWiki. April 7, 2023. Accessed April 9, 2023. https://wiki.archlinux.org/title/display_manager