Look and Feel

In the following sections, find examples of how to configure some look and feel aspects of your GNOME desktop, like desktop background and screens saver, 3D desktop effects, themes, window behavior, or menus.

Changing the Desktop Background

The desktop background is the image or color that is applied to your desktop. You can customize the desktop background in the following ways:

  • Select an image for the desktop background. The image is superimposed on the desktop background color. The desktop background color is visible if you select a transparent image or if the image does not cover the entire desktop.

  • Select a color for the desktop background. You can select a solid color or create a gradient effect with two colors. A gradient effect is a visual effect where one color blends gradually into another color.

To change the desktop preferences:

  1. Click Computer+Control Center+Look and Feel+Desktop Background.

  2. To change the picture on the background, select one of the Desktop Wallpapers from the list and select the style in which to arrange the image on the desktop.

  3. To use a custom picture, click Add Wallpaper and select an image file from the file system.

  4. If you do not want a picture on the background, specify a color scheme using the options in the Desktop Color drop-down list and the color selector buttons.

  5. When you are satisfied with your choices, click Close.

    Your desktop immediately changes to show the new settings.

Configuring Fonts

To select the fonts to use in your applications, windows, terminals, and desktop, click Computer+Control Center+Look and Feel+Fonts.

Figure 2.6. Font Preferences Dialog

Font Preferences Dialog

The upper part of the dialog shows the fonts selected for applications, documents, the desktop, window titles, and a fixed-width font for terminals. Click one of the buttons to open a selection dialog where you can set the font family, style, and size. For more information on the individual options, click Help.

Configuring Menus and Toolbars

You can configure the appearance and behavior of menus and toolbars. Click Computer+Control Center+Look and Feel+Menus & Toolbars.

If you want icons to appear in menus, select Show icons in menus. Not all menu items have icons.

If you want to be able to define new keyboard shortcuts for menu items, select Enable menu accelerators. When this option is enabled, you can change an application shortcut key by placing the mouse pointer over the menu item you want to change, then pressing the new key combination. To remove a shortcut key combination, place the mouse pointer over the menu item, then press <— or Del.

[Important]New Keyboard Combinations Can Change Defaults

If you assign a new keyboard combination, you are not warned if you select a combination that was previously assigned to something else. The previous assignment is removed and replaced by the new one. There is no automatic way to restore the original, default keyboard shortcut for a command. You must manually reassign the keyboard shortcut.

This feature does not maintain shortcuts that are normally assigned to all applications, such as Ctrl+C for copy. This might lead to inconsistencies in your GNOME applications.

If you want to be able to move toolbars to other locations on the screen, click Detachable toolbars. When this option is enabled, a handle displays on the left side of the toolbars in your applications. To move a toolbar, click and hold on the handle, then drag the toolbar to the new location.

Select one of the following options to specify how toolbar button labels display in your GNOME-compliant applications:

Text below icons

Displays icon labels below the icons for each button.

Text beside icons

Displays icons on the toolbar, with text beside the most important icons.

Icons only

Displays icons only, without any text labels.

Text only

Displays text labels on each button, without icons.

A preview of the selected option appears in the Menu and Toolbar Preferences dialog.

Configuring the Screen Saver

A screen saver is a program that blanks the screen or displays graphics when the computer is not used for a specified amount of time. Originally, screen savers protected monitors from having images burned into them. Now they are used primarily for entertainment or security.

To configure a screen saver, click Computer+Control Center+Look and Feel+Screensaver.

Figure 2.7. Screensaver Preferences Dialog

Screensaver Preferences Dialog

You can select from Random (random selection of screen savers from a custom-defined list), Blank Screen, or a selection of installed screen savers.

Select a screen saver from the list to choose it. The currently selected screen saver is displayed in the small preview window. Specify the amount of time that the screen is to be idle before the screen saver is activated, and whether the screen is locked when the screen saver is activated.

Choosing a Theme

A theme is a group of coordinated settings that specifies the visual appearance of a part of the desktop. You can choose themes to change the appearance of the desktop. Use the Theme Preferences tool to select from a list of preinstalled themes. The list of available themes includes several themes for users with accessibility requirements.

To choose a theme, click Computer+Control Center+Look and Feel+Theme.

A theme contains settings that affect different parts of the desktop, as follows:

Controls

The controls setting for a theme determines the visual appearance of windows, panels, and applets. It also determines the visual appearance of the GNOME-compliant interface items that appear on windows, panels, and applets, such as menus, icons, and buttons. Some of the controls setting options that are available are designed for special accessibility needs. You can select an option for the controls setting in the Controls tabbed page of the Theme Details tool.

Window frame

The window frame setting for a theme determines the appearance of the frames around windows only. You can select an option for the window frame setting in the Window Border tabbed page of the Theme Details tool.

Icon

The icon setting for a theme determines the appearance of the icons on panels and the desktop background. You can select an option for the icon setting in the Icons tabbed page of the Theme Details tool.

The color settings for the desktop and applications are controlled using themes. You can choose from a variety of preinstalled themes. Selecting a style from the list overview applies it automatically. Details opens another dialog where you can customize the style of single desktop elements, like window content, window borders, and icons. Making changes and leaving the dialog by clicking Close switches the theme to Custom Theme. Click Save Theme to save your modified theme under a custom name. The Internet and other sources provide many additional themes for GNOME as .tar.gz files. Install these with Install Theme.

Procedure 2.1. Creating a Custom Theme

The themes that are listed in the Theme Preferences tool are different combinations of controls options, window frame options, and icon options. You can create a custom theme that uses different combinations of options.

  1. Click Computer+Control Center+Look and Feel+Theme.

  2. Select a theme from the list of themes, then click Theme Details.

  3. Select the controls option that you want to use in the custom theme from the list in the Controls tabbed page.

  4. Click the Window Border tab, then select the window frame option that you want to use in the custom theme.

  5. Click the Icons tab, then select the icons option that you want to use in the custom theme.

  6. Click Close+Save Theme.

    A Save Theme to Disk dialog is displayed.

  7. Type a name and a short description for the custom theme in the dialog, then click Save.

    The custom theme now appears in your list of available themes.

Procedure 2.2. Installing a New Theme

You can add a theme to the list of available themes. The new theme must be an archive file that is tarred and zipped (a .tar.gz file).

  1. Click Computer+Control Center+Look and Feel+Theme.

  2. Click Install Theme.

  3. Specify the location of the theme archive file in the Location field, then click OK.

    You can also click Browse to browse for the file.

  4. Click Install to install the new theme.

Procedure 2.3. Installing a New Theme Option

You can install new controls options, window frame options, or icons options. You can find many controls options on the Internet.

  1. Click Computer+Control Center+Look and Feel+Theme.

  2. Click Theme Details, then click the tab for the type of theme you want to install.

    For example, to install an icons option, click the Icons tab.

  3. Click Install Theme.

  4. Specify the location of the theme archive file in the Location field, then click OK.

  5. Click Install to install the new theme option.

Procedure 2.4. Deleting a Theme Option

You can delete controls options, window frame options, or icons options.

  1. Click Computer+Control Center+Look and Feel+Theme.

  2. Click Theme Details, then click the tab for the type of option you want to delete.

  3. Click Go To Theme Folder.

    A file manager window opens on the default option folder.

  4. Use the file manager window to delete the option.

Customizing Window Behavior

Use the Window Preferences tool to customize window behavior for the desktop. You can determine how a window reacts to contact with the mouse pointer or to double-clicks on its title bar, and you can define which key to hold for moving an application window.

To customize window behavior, click Computer+Control Center+Look and Feel+Windows.

Figure 2.8. Window Preferences Dialog

Window Preferences Dialog

When several application windows populate the desktop, the active one by default is the one last clicked. Change this behavior by activating Select Windows When the Mouse Moves over Them. If desired, activate Raise Selected Window after an Interval and adjust the latency time with the slider. This raises a windows a short time after the window receives focus.

Application windows can be shaded (rolled up) by double-clicking the title bar, leaving only the title bar visible. This saves space on the desktop and is the default behavior. It is also possible to set windows to maximize when the title bar is double-clicked.

Using the radio buttons, select a modifier key to press for moving a window (Ctrl, Alt, Hyper, or the Windows key).

File Management Preferences

You can change the preferences for Nautilus file manager in the Control Center by clicking Computer+Control Center+Look and Feel+File Management, or from Nautilus by clicking Edit+Preferences.

Figure 2.9. File Manager Preferences

File Manager Preferences

  1. On the Views tab, define options for various Nautilus views, for example, select if Nautilus should also show hidden files and backup files.

  2. On the Behavior tab,you can define several options such as to open files or folders in Nautilus upon single or double mouse-click, or to include a Delete menu item in Nautilus which deletes files or folders directly from your file system instead of moving them to the trash.

  3. On the Display tab, configure the date format and the way icon captions appear in Nautilus.

  4. Switch to the List Columns tab to configure the columns that appear in Nautilus, as well as the order in which they appear.

  5. Click the Preview tab to specify for which files to show previews in Nautilus and if folders should the number of items they contain.

  6. For more information on the available options click Help.

  7. If all options are set according to your wishes, click Close to apply the changes.

Locking Desktop Functions

openSUSE ships with a graphical lockdown editor (pessulus package) that lets you disable (lockdown) certain desktop functions. This is useful if you want to restrict the actions that users can perform on a computer. For example, you might want to prevent command line operations on a computer that is for public use at a trade show.

If the pessulus package is already installed, start the Lockdown Editor from the main menu with Computer+Control Center+Look and Feel+Lockdown Editor or press Alt+F2 and enter pessulus.

Figure 2.10. General Lockdown Editor Settings

General Lockdown Editor Settings

When the Lockdown Editor starts, it tries to connect to the GConf mandatory configuration source (xml:merged:$prefix/etc/gconf/gconf.xml.mandatory). If you run pessulus as root, you have access to this configuration source and a lock icon is displayed next to the checkbox for each setting. Click the lock to specify if the setting is mandatory. If the setting is mandatory, regular users will not be able to change or override the setting. If you do not have access to the mandatory configuration source, the lock icon does not appear. In this case, all disabled settings are stored in the user's default configuration source and can be modified later using other tools such as gconf-editor or gconftool-2. For more information about GConf and mandatory configuration sources, see Using GConf in the GNOME Desktop System Administration Guide .

Click a category on the left to view the settings for this category that can be disabled.

  1. To disable printing (or prevent the user from modifying print settings), access to the command line, and saving to disk, set the according options in the General category.

  2. To lock down the panel, disable the panel applets you specify, and disable the force quit, lock screen, and log out options, use the options in the Panel category.

  3. To control access to features in Epiphany, use the options in the Epiphany Web Browser category.

  4. Use the options in the GNOME Screensaver category to lock the screen when the screen saver goes active, enable or disable the log out after a delay option in the unlock dialog box, and to enable or disable the switch user option in the unlock dialog box.

  5. For more information on the available options of each category, click Help.

  6. If all options are set according to your wishes, click Close to apply the changes.

Customizing the Main Menu

Use the Main Menu application to customize the GNOME Main menu. To start the application in system view, root privileges are needed. . To start the application in user view , click Computer+Control Center+Look and Feel+Main Menu - User View.

Figure 2.11. Main Menu Editor

Main Menu Editor

The Main Menu window shows the selected Editing Mode at the top. The current main menu submenus are displayed on the left of the main window, the items belonging to the selected submenu are shown on the right. Groups in a submenu are nested below that submenu. To find an item, click the arrow next to a submenu in the Menus list, select the group containing that item, then locate the item in the Items list.

[Note]Implications of Main Menu Changes

Changes you make to the main menu are not overwritten during a subsequent system update. Changes are applied after the latest menu view is generated.

Procedure 2.5. Editing the Main Menu

You can change the order in which items appear in the main menu, rename menu items, show or hide menu items, or delete items from the menu altogether, and add new menu items. For example, you might want to place your frequently used applications at the top of the menu or at the top of their groups to make them easier to find. Adding new items to the main menu is helpful when you install an application, but it is also useful if you have other applications that do not currently appear on the menu. You can also add a directory, a link, or another type of item to the menu.

  1. To move a menu item, click the menu item in the Items list on the right and drag it to a new location in the menu. You can move the item to a new location in the same menu, or drop it on an item in the Menus list to move it to a new menu or group. Use the Move Up and Move Down buttons to change an item’s location in the menu.

  2. To rename an existing menu item, right-click the item in the Items list, select Properties, and enter a new name.

  3. To hide an item so it does not appear in the menu, deactivate the checkbox next to the item in the Items list. An activated checkbox indicates that the item is currently shown in the menu. When an item is hidden, it still remains in the Items list and can be shown at any other time if you decide you want it to (re)appear in the menu.

  4. To delete an item from the Items list altogether, right-click the item and click Delete. If you want to show a deleted item in the menu again, you must add it like you would a new application.

  5. To add a new item, proceed as follows:

    1. In the Menus list, click the arrow next to the menu containing the group where you want to add the application, then select the group. The contents of that group appear in the Items list.

    2. Click New Item and select the Type of menu item to add. For example, to add a directory, select Directory.

    3. Click Browse and select the item to add.

    4. Enter a Name for the new menu item.

    5. If you want a short description to appear in the main menu if a user hovers the mouse pointer over the menu item, enter the description in the Comment field.

    6. If you want to assign an icon to the new item, click the image frame on the left, then select an icon for the item. If you do not select an icon, the item appears in the menu without an icon.

  6. If you want to restore the default menu layout, click Revert.

  7. If all options are set according to your wishes, click Close to apply your changes.

    [Note]

    The first time you use the Main Menu application to edit the menu, changes do not take effect until you log out and log back in. After the first time, changes appear immediately when you make them.

Improving Access for the Visually Impaired

The Orca screen reader assists visually impaired users so they can read the information on the screen, either by magnifying the screen, reading screen output aloud, or outputting information from the screen in Braille to a screen reader. To configure Orca, click Computer+Control Center+Look and Feel+Orca Screen Reader.

The first time you run this module, a terminal opens so you can set up the Orca screen reader. This setup consists of a series of yes/no questions. Answer the questions as appropriate for your setup. After the setup is complete, you must log out and log back in for your setup to take effect.

After the initial setup, to change the preferences you set during setup or to set additional options, click Computer+Control Center+Look and Feel+Orca Screen Reader.

Configuring Desktop Effects

Xgl is an X server architecture that lets you turn your desktop into a rotating 3D cube, tile windows so they do not overlap, and switch tasks while viewing live thumbnails. You can enable translucent or transparent windows, zoom in and out of the desktop screen, and use other window effects such as shadows, fading, and transformations. You can also configure windows to snap to other windows and screen edges when they are moved.

Figure 2.12. 3D Desktop

3D Desktop

Enabling Desktop Effects

To enable Xgl, you need a graphics adapter capable of providing 3D support, and you also need the graphics driver that Linux uses to operate the graphics adapter. This driver must be able to handle OpenGL (or 3D) requests from the Linux kernel. For a list of supported adapters, see the /etc/X11/xgl-hardware-list file that is included with the openSUSE installation. This file tells you which graphics cards are known to work with Xgl, which cards do not work with Xgl, and which cards might work with Xgl but are not supported because they are either too slow or contain too many known defects.

Your screen resolution must be within the 1024x768 to 1920x2000 range, and your color depth must be set at 24-bit. 3D acceleration must also be enabled. Use SaX2 to change your graphics card and monitor properties if necessary.

To enable desktop effects:

  1. Click Computer+Control Center.

  2. Click Desktop Effects in the Look and Feel group.

    The Desktop Effects tool analyzes your system and tries to determine whether or not you can run Xgl. If it finds anything wrong, it advises you on what actions you can take. For example, you might be advised to change your screen resolution or color depth, or to activate 3D acceleration. Follow the on-screen prompts to configure your system for Xgl.

  3. After your system is configured for Xgl, click Enable Desktop Effects.

  4. Type the root password, then click Continue.

  5. Click Log Out to log out of your session, then type your username and password to log back in.

    The default desktop effects are now enabled. For example, windows “wobble” when they first appear and when you move them, they fade away when you close them, and dragging a window to the far right of the screen rotates the desktop cube. To change any of these effects, see Section 2.3.11.2, “Modifying Desktop Effects”.

You can also enable Xgl by running the following command as root:

gnome-xgl-switch --enable-xgl

To disable Xgl, click Disable Desktop Effects in the Desktop Effects Settings dialog box, or run the following command as root:

gnome-xgl-switch --disable-xgl

Modifying Desktop Effects

Use the Desktop Effects Settings tool to enable or disable specific desktop effects, or to change the keystrokes or mouse actions used to control those effects.

Open Desktop Effects Settings from the main menu by clicking Computer+Control Center+Look and Feel+Desktop Effects.

Figure 2.13. Window Effects Tabbed Page

Window Effects Tabbed Page

  1. Use the options on the Window Effects tab to specify what happens when you move windows, how window transitions appear, and to change window opacity.

  2. Switch to the Desktop Cube tab to specify how many sides your desktop cube has, which keystroke and mouse button combination you can use to drag the cube, and to configure edge flipping.

  3. To configure window tiling, zooming, and water effects, click the Other Features tab.

  4. For more information on the individual options, click Help.

  5. If all options are set according to your wishes, click Close to apply the changes.

You can also use gconf-editor to change Xgl settings.

  1. Click Computer+More Applications+System+GNOME Configuration Editor or press Alt+F2 and enter gconf-editor.

  2. Navigate to the apps/compiz/general and apps/compiz/plugins registry folders and make the changes you want.

  3. Click File+Quit to close the Configuration Editor.

Xgl Shortcuts

The following table contains a list of the default keystrokes and mouse movements you can use to perform desktop effects. To change any of these shortcuts, see Section 2.3.11.2, “Modifying Desktop Effects”.

Table 2.1. Desktop Effects Shortcuts

Effect

Shortcut

Activate or deactivate rain effect

Shift+F9

Create ripples with the mouse pointer

Ctrl+Alt+Super (Windows key) and move the mouse pointer

Panoramic view of all desktop cubes

Ctrl+Alt+ (use the Left and Right arrows to scroll)

Rotate desktop cube

Ctrl+Alt+ or or drag a window to the edge of the screen

Rotate desktop cube manually

Ctrl+Alt+left-click the desktop and drag the mouse pointer

Rotate desktop cube while keeping the current active window with you

Ctrl+Alt+Shift+ or

Switch windows (thumbnail view)

Alt+→|

Tile windows

Ctrl+Alt+ or move the mouse pointer to the top left corner of the screen

Wobbly window

Left-click the window and drag

Zoom once

Super key (Windows key) and Button 3

Zoom in manually

Super key (Windows key) and scroll wheel up

Zoom out manually

Super key (Windows key) and scroll wheel down


More Desktop Effects

Here are some other things you can do with Xgl.

Switching Tasks

Press Alt+→| to display a thumbnail view of all windows open on your desktop. While holding the Alt key down, press →| to cycle through the list of windows. The currently highlighted window will appear in focus. Release the keys to access that window.

Figure 2.14. Thumbnail View

Thumbnail View

Unfolding the Cube

Press Ctrl+Alt+ to unfold the desktop cube, opening a panoramic view of all your desktops. Your desktop cube is laid out like a film strip on your screen, and you can use and to select a different screen. This is similar to the switcher feature (Alt+→|), but lets you view a thumbnail of your entire desktop instead of only your active windows.

Figure 2.15. Panoramic View of All Desktop Cubes

Panoramic View of All Desktop Cubes

Displaying a Skydome Image Behind the Cube

You can add background wallpaper (also known as a skydome image) that is visible when you rotate or unfold the desktop cube.

  1. Click Computer+More Applications+System+GNOME Configuration Editor or press Alt+F2 and enter gconf-editor.

  2. Navigate to the apps/compiz/plugins/cube/screen0/options registry folder.

  3. Scroll down the list on the right side of the Configuration Editor and select skydome.

  4. Double-click skydome_image and specify the path to the skydome image you want to display behind the cube.

    Skydome images must be in .png format. The suggested image sizes for skydome images are 1024 x 1024, 1024 x 2048, 1024 x 4096, 2048 x 1024, 2048 x 2048, 2048 x 4096, 4096 x 1024, 4096 x 2048, and 4096 x 4096.

  5. (Optional) Select skydome_animated to make it look like you are moving around the cube when you use your mouse to rotate the cube.

  6. Click OK.

  7. Click File+Quit to close the Configuration Editor.

Figure 2.16. Skydome Image

Skydome Image