Chapter 1. Starting using 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

GNOME 3 provides two essential environments:

  • GNOME Standard
  • GNOME Classic

Both environments can use two different protocols to build a graphical user interface:

  • 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.

Note

Note that the graphics based on the Wayland protocol are not available for virtual machines that use the qxl driver.

You can find the current list of environments for which Wayland-based graphics are unavailable in the /usr/lib/udev/rules.d/61-gdm.rules file.

The default combination in Red Hat Enterprise Linux 8 is GNOME Standard environment using GNOME Shell on Wayland as the display server.

However, due to Section 2.2, “Current Wayland limitations”, you may want to switch the graphics protocol stack.

You may also want to swich from GNOME Standard to GNOME Classic.

For more information about graphics based on the Wayland protocol, see Section 2.1, “Key differences between the Wayland and X11 protocol”.

For information on how to switch the environments, see Selecting GNOME environment.

1.2.1. GNOME Standard

GNOME Standard user interface includes these major components:

  • Top bar

    The horizontal bar at the top of the screen provides access to some of the basic functions of GNOME Standard, such as the Activities Overview, clock and calendar, system status icons, and the system menu.

  • System menu

    The system menu is located in the top right corner, and enables you:

    • Updating settings
    • Controlling the sound bar
    • Finding information about your Wi-Fi connection
    • Switching user
    • Logging out
    • Turning off the computer
  • Activities Overview

    The Activities Overview features windows and applications views that let the user run applications and windows and switch between them.

    The search entry at the top allows for searching various items available on the desktop, including applications, documents, files, and configuration tools.

    The vertical bar on the left side contains a list of favorite and running applications. You can add or remove applications from the default list of favorites according to your needs.

    The workspace list displayed on the right side allows the user to switch between multiple workspaces, or move applications and windows from one workspace to another.

  • Message tray

    The message tray provides access to pending notifications. The message tray shows when the user presses Super+M.

The GNOME 3 Standard Desktop

gnome standard new

1.2.2. GNOME Classic

GNOME Classic represents a mode for users who prefer a more traditional desktop experience that is similar to GNOME 2 environment used with Red Hat Enterprise Linux 6. It is based on GNOME 3 technologies, and at the same time it includes multiple features similar to GNOME 2.

GNOME Classic user interface consists of these major components:

  • Applications and Places

    The Applications menu is displayed at the top left of the screen. It gives the user access to applications organized into categories. If you enable window overview, you can also open the Activities Overview from that menu.

    The Places menu is displayed next to the Applications menu on the top bar. It gives the user quick access to important folders, for example Downloads or Pictures.

  • Taskbar

    The taskbar is displayed at the bottom of the screen, and features:

    • A window list
    • A notification icon displayed next to the window list
    • A short identifier for the current workspace and total number of available workspaces displayed next to the notification icon
  • Four available workspaces

    In GNOME Classic, the number of workspaces available to the user is by default set to 4.

  • Minimize and maximize buttons

    Window titlebars in GNOME Classic feature the minimize and maximize buttons that let the user quickly minimize the windows to the window list, or maximize them to take up all of the space on the desktop.

  • A traditional Super+Tab window switcher

    In GNOME Classic, windows in the Super+Tab window switcher are not grouped by application.

  • System menu

    The system menu is located in the top right corner, and enables you:

    • Updating settings
    • Controlling the sound bar
    • Finding information about your Wi-Fi connection
    • Switching user
    • Logging out
    • Turning off the computer

The GNOME 3 Classic Desktop with the Rhythmbox application and the Favorites submenu of the Applications menu

gnome classic new

In GNOME Classic, the overview of windows that are open is not available by default. You can see the list of all open windows in the taskbar at the bottom of the screen. However, you can enable the windows overview similar to what is by default available in GNOME Standard by changing the default settings of the GNOME Classic environment as described in Section 1.2.3, “Enabling window overview in GNOME Classic”.

1.2.3. Enabling window overview in GNOME Classic

In GNOME Classic, the overview of open windows is not available by default. This procedure enables the window overview for all users on the system.

Important

Enabling the window overview by this procedure is not a permanent change. Each update of the gnome-classic-session package overwrites the configuration file to the default settings, which disable the window overview.

To keep the window overview enabled, apply the procedure after each update of gnome-classic-session.

Procedure

  1. Open the /usr/share/gnome-shell/modes/classic.json file as the root user.
  2. Find the following line in the file:

    "hasOverview": false
  3. Change the line to the following:

    "hasOverview": true
  4. Save changes, and close the /usr/share/gnome-shell/modes/classic.json file.
  5. Restart the user session.

Verification steps

  1. In your GNOME Classic session, open multiple windows.
  2. Press the Super key to open the window overview.
  3. In the overview, check that:

    • The Dash (the vertical panel on the left side of the screen) is displayed.
    • The bottom panel is not displayed.
    • The workspace switcher is displayed on the right side of the screen.

      Window overview with "hasOverview": true

      has overview true

    With the default settings ("hasOverview": false), the overview has the following features:

    • The Dash is not displayed.
    • The bottom panel is displayed. It includes the Window picker button in its left part and the workspace switcher in its right part.

      Window overview with "hasOverview": false

      has overview false

1.3. 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 hor corner system-wide, use the No topleft hot corner extension.

1.3.1. 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.

1.3.1.1. 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

For more information on dconf Editor application, see Section 4.3, “Displaying GSettings values for desktop applications”.

1.3.1.2. Disabling hot corner using gsettings

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

Procedure

  • Enter the following command to 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

1.3.2. 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 1.12, “Customizing GNOME Shell environment with the Tweaks tool”.

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

1.4. Selecting GNOME environment and display protocol

The default desktop environment for Red Hat Enterprise Linux 8 is GNOME Standard with GNOME Shell on Wayland as the display server.

However, due to Section 2.2, “Current Wayland limitations”, you may want to switch the graphics protocol stack.

You may also want to swich from GNOME Standard to GNOME Classic. See Section 1.2, “GNOME environments” for differences between these two environments.

For switching between various combinations of GNOME environment and graphics protocol stacks, use the following procedure.

Procedure

  1. From the login screen (GDM), click the cogwheel next to the Sign In button.

    Note

    You cannot access this option from the lock screen. The login screen appears when you first start Red Hat Enterprise Linux 8 or when you log out of your current session.

    gnome environments new

  2. From the drop-down menu that appears, select the option that you prefer.

    Note

    Note that in the menu that appears on the login screen, the X.Org display server is marked as X11 display server.

Important

The change of GNOME environment and graphics protocol stack resulting from the above procedure is persistent across user logouts, and also when powering off or rebooting the computer.

1.5. Launching applications

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

Procedure

  1. Press Alt+F2 to make the Enter a Command screen appear.
  2. Write the name of the executable into the Enter a Command screen:

    enter a command screen new

This approach works both in GNOME Standard and GNOME Classic environment.

Procedure

  • In GNOME Standard, go to Activities Overview and click on the Show Applications icon in the vertical bar on the left side.

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

    Alternatively, you can also start typing the name of the required application in the search entry.

    launching applications new

Procedure

  1. In GNOME Classic, go to Applications menu.
  2. Choose the required application from one of the available categories.

    The available categories include:

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

Procedure

  1. Open a terminal.
  2. Type the name of the required application on the command line.

This approach works both in GNOME Standard and GNOME Classic environment.

1.6. Installing applications

This section describes various approaches that you can use to install a new application in GNOME 3.

Procedure

  1. Use one of the approaches described in Launching applications to launch GNOME Software.

    Note

    GNOME Software is a utility, which enables you to install and update applications and gnome-shell extensions through a graphical environment. This utility is based on the PackageKit technology, which serves as its back end. GNOME Software offers mainly the desktop applications, which are the applications that include the *.desktop file. The available applications are grouped into multiple categories according to their purpose.

  2. Choose the application to be installed from one of the available categories.

    • Audio & Video
    • Communication & News
    • Productivity
    • Graphics & Photography
    • Add-ons
    • Developer Tools
    • Utilities

      gnome software new

  3. Click the selected application, and then click the Install button.

    gnome software install photos1 new

    gnome software install photos2 new

    Note

    Add-ons include for example GNOME Shell extensions, codecs or fonts.

Procedure

  1. Start opening a file that is associated with an application or applications that are currently not installed on your system.
  2. GNOME will automatically identify suitable application in which the file can be opened, and will offer to download the application.

Procedure

  1. Download the required rpm package.
  2. Open the directory that includes the downloaded rpm in the Nautilus file manager.

    Note

    The downloads are by default stored in the /home/user/Downloads directory.

  3. Double-click the icon of the rpm to install it.

Procedure

  1. Start typing the name of the required application in the search entry.

    install gimp 1 new

GNOME will automatically find the application in a respective repository, and will display the application’s icon.

  1. Click the application’s icon that automatically appears to open GNOME Software.

    install gimp 2

  2. Click again the icon of the application and finish the installation in GNOME Software as described above.

    install gimp 3

Procedure

  1. Open a terminal.
  2. Run the yum install command with the name of the required application:

    ~]# yum install <application_name>

1.7. Desktop icons

In RHEL 8, the Desktop icons functionality is no longer provided by the Nautilus file manager, but by the desktop icons gnome-shell extension available in 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 cannot be turned off. If you want to create a desktop icon for a file, you just need to put this file into the /Desktop directory, and the icon appears automatically.

Desktop icons in GNOME Standard

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

After the package has been installed, you can switch the desktop icons on or off by using the Tweaks application:

  1. Go to Tweaks, and select Extensions - Desktop icons, and switch it on.

    desktop icons on

  2. Put the required file into the /Desktop directory, and the icon appears automatically on your desktop.

1.8. Handling sound

In Red Hat Enterprise Linux 8, sound is handled by the PulseAudio sound server that lets programs output the audio using the Pulseaudio daemon.

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

To handle sound, you can use one of these two graphical applications in GNOME:

  • System menu
  • Tweaks tool
  • GNOME Control Center

System menu is located in the top right corner, and it only enables you 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 supposed to use an iternal microphone (built-in audio), such as some teleconference tools.

system menu sound new

Tweaks tool only enables you to configure the Over-Amplification.

tweaks sound

GNOME Control Center provides more options to configure sound. You can launch this tool by using one of the approaches described in Launching applications. Moreover, you can also launch it from the System menu by clicking on its icon.

system menu gcc new

When GNOME Control Center opens, choose Sound from the left vertical bar.

gcc sound

Through GNOME Control Center - Sound, you can configure the following:

  • Output sound
  • Input sound
  • Sound effects
  • Applications

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.

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.

1.9. 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.

1.10. Handling printing

In GNOME Shell, printing can be set up using the GNOME Control center GUI.

1.10.1. Starting GNOME control center for setting up printing

Procedure

  1. Use one of the approaches described in Section 1.5, “Launching applications” 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

1.10.2. 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

1.10.3. 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

1.10.4. 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

1.10.5. 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

1.11. 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

1.12. Customizing GNOME Shell environment with the Tweaks tool

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

To open Tweaks, use one of the approaches described in Section 1.5, “Launching applications”.

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 Statup 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