Chapter 1. Getting started with GNOME

1.1. What GNOME 3 is

Red Hat Enterprise Linux 8 is shipped with the default desktop environment GNOME 3.

GNOME 3 represents a presentation layer that provides a graphical user interface as well as the focused working environment, which enables you to access all your work from one place.

1.2. GNOME environments, back ends, and display protocols

GNOME 3 provides two user environments:

  • GNOME Standard
  • GNOME Classic

Both environments can use two different protocols as their graphical back ends:

  • The X11 protocol, which uses X.Org as the display server.
  • The Wayland protocol, which uses GNOME Shell as the Wayland compositor and display server.

    This solution of display server is further referred as GNOME Shell on Wayland.

The default combination in RHEL 8 is GNOME Standard environment using GNOME Shell on Wayland as the display server. However, due to certain Wayland limitations, you might want to switch the graphics protocol stack to X11. You may also want to switch from GNOME Standard to GNOME Classic.

Additional resources

1.3. Launching applications in GNOME

This section describes various approaches that you can use to launch available applications in GNOME 3.

1.3.1. Launching an application in GNOME Standard

This procedure launches a graphical application in the GNOME Standard user environment.

Prerequisites

  • You are using the GNOME Standard environment.

Procedure

  1. Go to the Activities Overview screen.
  2. Find the application using either of the following ways:

    • Click the Show Applications icon in the vertical bar on the left side.

      Optionally, you can choose between displaying all or just the frequent applications by using the Frequent or All switch at the bottom of the screen.

      launching applications new

    • Start typing the name of the required application in the search entry.
  3. Click an application from the displayed list.

1.3.2. Launching an application in GNOME Classic

This procedure launches a graphical application in the GNOME Classic user environment.

Prerequisites

  • You are using the GNOME Classic environment.

Procedure

  1. Go to the Applications menu.
  2. Choose the required application from the available categories, which include:

    • Favorites
    • Accessories
    • Internet
    • Office
    • Sound & Video
    • Sundry
    • System Tools
    • Utilities

1.3.3. Launching an application in GNOME using a command

This procedure launches a graphical application in GNOME by entering a command.

Prerequisites

  • You know the command that starts the application.

Procedure

  1. Open a command prompt using either of the following ways:

    • Open a terminal.
    • Press the Alt+F2 shortcut to open the Enter a Command screen.

      enter a command screen new

  2. Write the command in the command prompt.
  3. Confirm the command by pressing Enter.

1.4. Managing desktop icons

You can enable the desktop icons functionality and move files to the desktop.

1.4.1. Desktop icons in RHEL 8

In RHEL 8, the Files application no longer provides the desktop icons functionality. Instead, desktop icons are provided by the Desktop icons GNOME Shell extension, which is available from the gnome-shell-extension-desktop-icons package.

Desktop icons in GNOME Classic

The GNOME Classic environment includes the gnome-shell-extension-desktop-icons package by default. Desktop icons are always on, and you cannot turn them off.

Desktop icons in GNOME Standard

In GNOME Standard, desktop icons are disabled by default.

If you have only the GNOME Standard environment available, and not GNOME Classic, you must install the gnome-shell-extension-desktop-icons package.

1.4.2. Enabling desktop icons in GNOME Standard

This procedure enables the desktop icons functionality in the GNOME Standard environment.

Procedure

  1. Install the gnome-shell-extension-desktop-icons package:

    # yum install gnome-shell-extension-desktop-icons
  2. Open the Tweaks application.
  3. Select ExtensionsDesktop icons, and enable the extension.

    desktop icons on

1.4.3. Creating a desktop icon for a file

This procedure creates a desktop icon for an existing file.

Prerequisites

  • The Desktop icons extension is enabled.

Procedure

  • Move the selected file into the ~/Desktop/ directory.

Verification steps

  • Check that the icon for the file appears on the desktop.

1.5. Disabling the hot corner functionality on GNOME Shell

The GNOME environment provides the hot corner functionality, which is enabled by default. This means that when you move the cursor to the area of the top left corner and press the cursor in this area, the Activities Overview menu opens automatically.

However, you may want to disable this feature to not open Activities Overview unintentionally.

To do so, you can use the following tools:

  • The dconf Editor application
  • The gsettings command-line utility
  • The No topleft hot corner extension

The selection of the tool might depend on whether you want to disable the hot corner functionality for a single user or for all users on the system. By using dconf Editor or gsettings, you can disable hot corner only for a single user. To disable hot corner system-wide, use the No topleft hot corner extension.

1.5.1. Disabling the hot corner functionality for a single user

To disable the hot corner functionality for a single user, you can use either the dconf Editor application or the gsettings command-line utility.

1.5.1.1. Disabling hot corner using dconf Editor

To disable the hot corner functionality using the dconf Editor application, follow this procedure.

Prerequisites

  • The dconf Editor application is installed on the system:

    # yum install dconf-editor

Procedure

  1. Open the dconf Editor application.
  2. Choose the org.gnome.desktop.interface menu.
  3. Find the enable-hot-corners option.

    This option is by default set to On.

    Default settings of enable-hot-corners

    dconf enable hot corners 1

  4. Set enable-hot-corners to False.

    You can do this either by:

    • Setting enable-hot-corners to Off in the same window.
    • Clicking the line with enable-hot-corners, and proceeding to a new window.

      In the new window, you can switch the hot corner feature off.

      Switching the hot corner functionality off

      dconf enable hot corners 2

Additional resources

1.5.1.2. Disabling hot corner using gsettings

To disable the hot corner functionality using the gsettings command-line utility, follow this procedure.

Procedure

  • Disable the hot corner feature:

    $ gsettings set org.gnome.desktop.interface enable-hot-corners false

Verification steps

  • Optionally, verify that the hot corner feature is disabled:

    $ gsettings get org.gnome.desktop.interface enable-hot-corners
    
    false

1.5.2. Disabling the hot corner functionality for all users

With the GNOME Shell extension called No topleft hot corner provided by the gnome-shell-extension-no-hot-corner package, you can disable the hot corner feature system-wide.

Prerequisites

  • The gnome-shell-extension-no-hot-corner package is installed on the system:

    # yum install gnome-shell-extension-no-hot-corner

Procedure

  1. Enable the No topleft hot corner extension by switching it on in the Tweaks tool.

    For more information on how to use Tweaks, see Section 1.10, “Customizing GNOME Shell environment with the Tweaks tool”.

  2. Log out, and restart the user session so that the extension can take effect.

1.6. Configuring sound in GNOME

You can configure sound volume and other sound options in GNOME.

1.6.1. Sound configuration tools in GNOME

In RHEL 8, the PulseAudio sound server handles sound output and input. PulseAudio lets programs output the audio using the pulseaudio daemon.

To configure sound, you can use one of the following graphical applications in GNOME:

System menu

System menu is located in the top-right screen corner. It enables you only to set the intensity of the sound output or sound input through the sound bar. The sound bar for input sound is available only if you are running an application that is using an internal microphone (built-in audio), such as some teleconference tools.

system menu sound new

Tweaks

Tweaks enables you to configure only volume over-amplification.

tweaks sound

GNOME Control Center
GNOME Control Center provides more options to configure sound.

Additional resources

  • For more information on PulseAudio, see the pulseaudio man page.

1.6.2. Accessing sound configuration in GNOME Control Center

This procedure opens the sound configuration screen in the GNOME Control Center application.

Procedure

  1. Launch GNOME Control Center.

    You can use one of the approaches described in Section 1.3, “Launching applications in GNOME”. Alternatively, you can also launch it from the System menu by clicking on its icon.

    system menu gcc new

  2. In GNOME Control Center, choose Sound from the left vertical bar.

1.6.3. Sound options in GNOME Control Center

Through the GNOME Control Center Sound menu, you can configure the following sound options:

Output and Input

The Output and Input menus show only the built-in audio devices unless you connect any external device that can handle sound.

The Output menu enables you to select the required profile from available analog or digital profiles that are displayed depending on available output devices.

Sound Effects
The Sound Effects menu sets the volume and theme of system audio alerts.
Applications
The Applications menu shows all currently running applications that can process sound, and allows you to amplify or lower the sound of a particular application.

The Output tab on the sound configuration screen

gcc sound

1.7. Handling graphics and photos

GNOME Shell provides multiple tools to handle graphics and photography.

You can check the available tools under the Graphics & Photography menu in GNOME Software:

  1. Open the GNOME software.

    gnome software1

  2. Go to Graphics & Photography. gnome software graphics and photo

The available tools include:

  • Photos

    For accessing, organizing and sharing your photos.

  • GNU Image Manipulation Program

    For creating images and editing photographs.

  • Inkspace

    For creating and editing scalable vector graphics images.

  • XSane

    For scanning images with a scanner.

  • LibreOffice Draw

    For create and editing drawings, flow charts, and logos.

1.8. Handling printing

In GNOME, you can set up printing using the GNOME Control Center GUI.

1.8.1. Starting GNOME control center for setting up printing

Procedure

  1. Use one of the approaches described in Section 1.3, “Launching applications in GNOME” to start the GNOME Control Center GUI.

    Moreover, you can also start the GNOME Control center from the system menu in the top right corner by clicking on the "Settings" icon.

    system menu gcc new
  2. When the GNOME Control center GUI appears, go to:

DevicesPrinters

Figure 1.1. GNOME Control center configuration tool

gnome control center add printer

1.8.2. Adding a new printer in GNOME Control Center

This section describes how to add a new printer using the GNOME Control Center GUI.

Prerequisites

To be able to add a new printer using the GNOME Control Center GUI, you must click on Unlock, which appears on the right side of the top bar, and authenticate as one of the following users:

  • Superuser
  • Any user with the administrative access provided by sudo (users listed within /etc/sudoers)
  • Any user belonging to the printadmin group in /etc/group
add printer gcc unlock authenticate

Procedure

  1. Open the Add Printer dialog.

    gnome control center add printer
  2. Select one of the available printers (including also network printers), or enter printer IP address or the hostname of a printer server.

    gnome control center select printer
    gnome control center add network printer

1.8.3. Configuring a printer in GNOME Control Center

This section describes how to configure a new printer, and how to maintain a configuration of a printer using the GNOME Control Center GUI.

Displaying printer’s settings menu

Procedure

  • Click the "settings" button on the right to display a settings menu for the selected printer:

    gnome control center printer settings
Displaying and modifying printer’s details

Procedure

  • Click Printer Details to display and modify selected printer’s settings:

    gnome control center printer details

With this menu you can:

  • Search for Drivers

    GNOME Control Center communicates with PackageKit that searches for a suitable driver suitable in available repositories.

  • Select from Database

    This option enables you to select a suitable driver from databases that have already been installed on the system.

  • Install PPD File

    This option enables you to select from a list of available postscript printer description (PPD) files that can be used as a driver for your printer.

gnome control center printer details more
Setting the default printer

Procedure

  • Click Use Printer by Default to set the selected printer as the default printer:

    gnome control center default printer
Removing a printer

Procedure

  • Click Remove Printer to remove the selected printer:

    gnome control center remove printer

1.8.4. Printing a test page in GNOME Control Center

This section describes how to print a test page to make sure that the printer functions properly.

You might want to print a test page if one of the below prerequisites is met.

Prerequisites

  • A printer has been set up.
  • A printer configuration has been changed.

Procedure

  1. Click the "settings" button on the right to display a settings menu for the selected printer:

    gnome control center printer settings
  2. Click Printing OptionsTest Page

1.8.5. Setting print options using GNOME Control Center

This section describes how to set print options using the GNOME Control Center GUI.

Procedure

  1. Click the "settings" button on the right to display a settings menu for the selected printer:

    gnome control center printer settings
  2. Click Printing Options

1.9. Sharing media between applications

Red Hat Enterprise Linux 8 includes the PipeWire media server, which ensures access to multimedia devices and media sharing between applications.

When running a remote desktop session on GNOME Shell on Wayland, PipeWire and the VNC server is used. The functionality of remote desktop session is provided by the gnome-remote-desktop and pipewire packages.

On X.Org, just VNC is needed to run a remote desktop session. This functionality on X.Org is provided by the vino package.

PipeWire is used also with teleconference tools such as BlueJeans when running on GNOME Shell on Wayland. In such case, the pipewire service is activated automatically when you start sharing your screen within the teleconference tool.

To check the status of the pipewire service, run:

~]$ systemctl --user status pipewire

1.10. Customizing GNOME Shell environment with the Tweaks tool

You can customize the GNOME Shell environment for a particular user by using the Tweaks tool.

  1. Open Tweaks.
  2. To choose the required item that you want to customize, use the vertical menu on the left. For example you can choose the applications to start automatically when you log in by using the Startup Applications menu, or you can customize your top bar appearance by using the Top Bar menu.

The Tweaks tool

tweaks tool

Customizing startup applications in Tweaks

startup applications

Customizing the appearance of your top bar in Tweaks

tweaks top bar