2.2 Look and Feel

Look and Feel settings include the following:

2.2.1 Customizing the Desktop Appearance

Use the Appearance module to customize the look of the desktop. With this module you can change the desktop theme, fonts, and background, as well as changing the look of menus and the main toolbar.

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 > Appearance, then click the Theme tab.

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. Customize opens another dialog where you can customize the style of single desktop elements, like window content, window borders, pointers, and icons. Making changes and leaving the dialog by clicking Close switches the theme to Custom Theme. Click Save As 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 the Install theme.

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 > Appearance, then click the Theme tab.

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

    The following settings can be customized:

    • 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.

    • Colors

      The color settings determine the colors of various screen elements. Set the colors to provide an appearance that most appeals to you.

    • Window Border

      The window border 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.

    • Icons

      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.

    • Pointer

      You can set the appearance and size of your mouse pointer so it is appealing and easy to see with your chosen theme.

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

  4. Click the Colors tab, then select the colors you want to use for the available interface elements.

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

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

  7. Click the Pointer tab, then select the desired mouse pointer.

    The following table lists the mouse pointer preferences you can modify.

    Table 2-7 Pointer Options

    Option

    Description

    Cursor Theme

    Displays the available cursor themes.

    Highlight the Pointer When You Press Ctrl

    Enables a mouse pointer animation when you press and release Ctrl. This feature can help you locate the mouse pointer.

  8. Click Close > Save As.

    The Save Theme to Disk dialog is displayed.

  9. 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.

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 > Appearance, then click the Theme tab.

  2. Click Install.

  3. Browse to the location of the theme archive file, select the archive, then click Open.

  4. Click Apply New Theme to apply the theme.

    or

    Click Keep Current Theme to continue using the currently applied theme.

Deleting a Theme

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

  1. Click Computer > Control Center > Look and Feel > Appearance, then click the Theme tab.

  2. Select the theme you want to delete.

  3. Click Delete.

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 > Appearance, then click the Background tab.

  2. Set the background preferences the way that you want them.

    The following settings can be changed:

    Table 2-8 Background Preferences

    Option

    Description

    Desktop Wallpaper

    Displays an image of your choice on the desktop.

    Style

    Determines what processing steps should be applied to the selected image to adapt it optimally to the current screen resolution. To specify how to display the image, select one of the following options from the Style drop-down list:

    • Centered: Displays the image in the middle of the desktop.

    • Fill Screen: Enlarges the image to cover the desktop and maintains the relative dimensions of the image.

    • Scaled: Enlarges the image until the image meets the screen edges and maintains the relative dimensions of the image.

    • Tiled: Repeats the image over the entire screen.

    Add Wallpaper

    Opens a dialog where you can select an image file to use as the background picture.

    Remove

    Removes a Desktop Wallpaper after you select it and then click Remove.

    Desktop Colors

    Lets you specify a color scheme using the options in the Desktop Color drop-down list and the color selector buttons. You can specify a color scheme using any of the following options:

    • Solid Color specifies a single color for the desktop background.

      To select a color, click Color. In the Pick a Color dialog, select a color and then click OK

    • Horizontal Gradient creates a gradient effect from the left screen edge to the right screen edge.

      Click Left Color to display the Pick a Color dialog, then select the color that you want to appear at the left edge.

      Click Right Color, then select the color that you want to appear at the right edge.

    • Vertical Gradient creates a gradient effect from the top screen edge to the bottom screen edge.

      Click Top Color to display the Pick a Color dialog, then select the color that you want to appear at the top edge.

      Click Bottom Color, then select the color that you want to appear at the bottom edge.

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

    Your desktop immediately changes to show the new settings.

Configuring Fonts

You can select the fonts to use in your applications, windows, terminals, and desktop. To set the Font preferences, click Computer > Control Center > Look and Feel > Appearance, then click the Fonts tab.

Figure 2-10 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.

To specify how to render fonts on your screen, select one of the following options:

  • Monochrome: Renders fonts in black and white only. The edges of characters might appear jagged in some cases because the characters are not antialiased. Antialiasing is an effect that is applied to the edges of characters to make the characters look smoother.

  • Best Shapes: Antialiases fonts where possible. Use this option for standard Cathode Ray Tube (CRT) monitors.

  • Best Contrast: Adjusts fonts to give the sharpest possible contrast and antialiases fonts so that characters have smooth edges. This option might enhance the accessibility of the GNOME desktop to users with visual impairments.

  • Subpixel Smoothing (LCDs): Uses techniques that exploit the shape of individual Liquid Crystal Display (LCD) pixels to render fonts smoothly. Use this option for LCD or flat-screen displays.

Click Details to specify further details of how to render fonts on your screen:

  • Resolution (Dots Per Inch): Use the spin box to specify the resolution to use when your screen renders fonts.

  • Smoothing: Select one of the options to specify how to antialias fonts.

  • Hinting: Select one of the options to specify how to apply hinting to improves the quality of fonts at small sizes and at low screen resolutions.

  • Subpixel Order: Select one of the options to specify the subpixel color order for your fonts. Use this option for LCD or flat-screen displays.

Configuring Menus and Toolbars

You can configure the appearance and behavior of menus and toolbars. Click Computer > Control Center > Look and Feel > Appearance, then click the Interface tab.

Showing Icons in Menus

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

Defining New Keyboard Shortcuts

If you want to be able to define new keyboard shortcuts for menu items, select Editable menu shortcut keys. 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 Backspace or Delete.

IMPORTANT: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.

Configuring Placement of Toolbar Button Labels

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.

2.2.2 Configuring Desktop Effects

Xgl is an Xserver architecture that lets you turn your desktop into a rotating 3-D cube, tile windows so they don’t 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 2-11 3-D Desktop

Enabling Desktop Effects

To enable Xgl, you need a graphics adapter capable of providing 3-D 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 3-D) 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. 3-D 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 3-D 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 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.

  1. Click Computer > Control Center.

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

  3. Choose from the following options:

  4. When you finish making changes, click Close.

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.

Window Effects

Use the options on this tabbed page to specify what happens when you move windows, how window transitions appear, and to change window opacity.

Figure 2-12 Window Effects Tabbed Page

Moving Windows

By default, windows appear transparent when you move them. If you want window edges to stick (snap) to other windows and workspace edges when you hold down the Shift key while moving the window, both the Windows wobble while they’re being moved and Window edges stick to other windows when you hold down “Shift” options must be selected.

You can also choose to make windows appear distorted (wobbly) as you move or resize them, giving the impression that the window is more fluid than rigid.

Window Transitions

These options let you add a fade-in and fade-out effect to windows and menus when you open and close them. Windows will also shrink smoothly onto the task bar when they are minimized and will grow smoothly back to their normal size when they are reopened.

Translucent Windows

This option lets you use the scroll wheel to change how transparent a window appears on-screen. Select Use scroll wheel plus these modifiers to change window opacity, then select the button or combination of buttons you want to use. Select a window, hold down the button or buttons you selected, then scroll the mouse wheel up or down to change the transparency of the window.

Figure 2-13 Translucent Window

Desktop Cube

Use the options on this tabbed page 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.

Figure 2-14 Desktop Cube Tabbed Page

Desktop Cube

By default, this option gives you four desktops on the faces of a virtual cube that you can rotate to access each desktop. This provides extra space in which to arrange open applications and windows. For example, you can put an editor on one desktop, some shells on another, and your e-mail application and Web browser on the third desktop. Using Ctrl+Alt+Left arrow and Ctrl+Alt+Right arrow, you can rotate the cube to access the programs running in the selected desktop and avoid windows piled on top of each other on one desktop.

Dragging a window to the edge of the screen rotates the cube and places the window on the new desktop. To rotate the cube manually in 3-D, press Ctrl+Alt, left-click the desktop, then drag the mouse pointer. Ctrl+Alt+Shift+Left-arrow or Right-arrow lets you rotate the cube while taking the currently selected window with you.

Use the options under Drag the cube with the mouse by using to change the default keystrokes used to rotate the cube.

For information on how to add an image behind your cube, see Displaying a Skydome Image Behind the Cube.

Edge Flipping

When edge flipping is enabled, the desktop cube rotates to the next face when you bump the mouse pointer to the edge of the screen. You can choose to always enable edge flipping or to enable edge flipping only when you drag a window or icon to the edge of the desktop.

Use the slider bar at the bottom of the tabbed window to specify how long (in microseconds) it takes to rotate the cube after you bump the edge of the desktop with a window or the mouse pointer.

Other Features

Use the options on this tabbed page to configure window tiling, zooming, and water effects.

Figure 2-15 Other Features Tabbed Page

Window Picker

This option lets you tile (or scale) the windows on your desktop so that you can see what windows you have open and select a specific one. This also provides you with a snapshot of all applications open on your desktop. Pressing Ctrl+Alt+Up-arrow shrinks all windows and rearranges them on the screen so that they do not overlap. Selecting a window with the mouse causes all windows to return to their original size and position, with the selected window on top.

To change the keystrokes used to tile windows, click the box to the right of Activate/deactivate when I type until New accelerator appears. Then press the keystrokes you want to use. The new keystrokes appear in the box.

You can also choose to tile windows by moving the mouse pointer to the top left (default), top right, bottom left, or bottom right of the screen.

Figure 2-16 Application Tiling

Zoom

These options give you the ability to zoom in and out of areas on your screen, which significantly improves desktop accessibility for visually impaired users or for anyone who wants to see a part of the screen displayed in a larger size.

By default, pressing the Super key (the Windows key)+Button 3 zooms in on part of the desktop. If you have a two-button mouse, press the Super key, then press the left and right buttons simultaneously. You can move the mouse while holding those buttons down to see other parts of the screen. You can also press the Super key and use the scroll wheel on the mouse to manually zoom in and out of the desktop.

You can choose to deactivate any of these options, or to change the zoom keystrokes.

Water Effect

This option creates a ripple effect on your screen when you hold down the specified key or key combination (Ctrl+Alt+Super by default) and move the mouse pointer. You can also enable or disable a rain effect when you press Shift+F9. To change the keystrokes used to enable and disable the rain effect, click the box to the right of Activate/deactivate rain when I type until New accelerator appears. Then press the keystrokes you want to use. These new keystrokes will appear in the box.

Use the slider bar at the bottom of the tabbed window to specify the intensity of the rain effect.

Figure 2-17 Water Effect

Xgl Shortcuts

Table 2-9 contains a list of the default keystrokes and mouse movements you can use to perform desktop effects. To change any of these shortcuts, see Modifying Desktop Effects.

Table 2-9 Desktop Effects Shortcuts

Effect

Shortcut

Activate or deactivate rain effect

Shift+F9

Create ripples with the mouse pointer

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

Panoramic view of all desktop cubes

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

Rotate desktop cube

Ctrl+Alt+Left-arrow or Right-arrow 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+Left-arrow or Right-arrow

Switch windows (thumbnail view)

Alt+Tab

Tile windows

Ctrl+Alt+Up-arrow 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)+Button 3

Zoom in manually

Super key (Windows key)+scroll wheel up

Zoom out manually

Super key (Windows key)+scroll wheel down

More Desktop Effects

You can also do these things with Xgl:

Switching Tasks

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

Figure 2-18 Thumbnail View

Unfolding the Cube

Press Ctrl+Alt+Down-arrow to unfold the desktop cube, opening a panoramic view of all your desktops. Your desktop cube is laid out like a filmstrip on your screen. You can use the Left-arrow and Right-arrow to select a different screen. This is similar to the switcher feature (Alt+Tab), but lets you view a thumbnail of your entire desktop instead of only your active windows.

Figure 2-19 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, then 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 2-20 Skydome Image

2.2.3 File Management Preferences

You can change the File Manager preferences in the Control Center by clicking Computer > Control Center > Look and Feel > File Management, or from Nautilus by clicking Edit > Preferences. The configurable preferences are organized on five tabs:

Views

To configure the appearance of the File Manager, click Computer > Control Center > Look and Feel > File Management (or Edit > Preferences from Nautilus), then click the Views tab.

Figure 2-21 File Manager Views Dialog Box

Select from the following options:

Table 2-10 File Manager Views Options

Section

Option

Description

Default View

View new folders using

Determines whether new folders are displayed as icons or as a list.

 

Arrange items

Sets the order in which items are listed. Items can be listed by name, size, type, modification date, or emblems.

 

Sort folder before files

Places this folder at the top of the list, if this check box is selected (the default).

Show hidden and backup files

Shows hidden files and backup files in your directories. If this check box is not selected (the default), hidden and backup files do not appear.

Icon View Defaults

Default zoom level

Sets the size of items that appear in the File Manager.

 

Use compact layout

Displays items closer together.

 

Text beside icons

Displays icon captions next to the icons, rather than beneath them.

List View Defaults

Default zoom level

Determines the size of items that appear in the list view.

Tree View Defaults

Show only folders

When selected, displays folders in the tree in the side pane.

Behavior

To configure the behavior of the File Manager, click Computer > Control Center > Look and Feel > File Management (or Edit > Preferences from Nautilus), then click the Behavior tab.

Figure 2-22 File Manager Behavior Dialog Box

Select from the following options:

Table 2-11 File Manager Behavior Options

Option

Description

Single click to activate items

Performs the default action for an item when you click the item. If this option is selected and you point to an item, the title of the item is underlined.

Double click to activate items

Performs the default action for an item when you double-click the item.

Always open in browser windows

Opens the File Manager in Browser mode whenever you open it.

Run executable text files when they are opened

Runs an executable file when you open the file. An executable file is a text file than can execute (that is, a shell script).

View executable text files when they are opened

Displays the contents of an executable file when you open the file.

Ask each time

Displays a dialog when you click an executable file. The dialog asks whether you want to execute the file or display the file.

Ask before emptying the Trash or deleting files

Displays a confirmation message before the Trash is emptied or before files are deleted.

Include a Delete command that bypasses Trash

Adds a Delete menu item to the Edit menu and the pop-up menu that is displayed when you right-click a file, folder, or desktop object. When you select an item and click Delete, the item is immediately deleted from your file system.

Display

To configure the way icon captions and dates appear in the File Manager, click Computer > Control Center > Look and Feel > File Management (or Edit > Preferences from Nautilus), then click the Display tab.

Figure 2-23 File Manager Display Dialog Box

Select from the following options:

Table 2-12 File Manager Display Options

Option

Description

Icon Captions

Sets the order of information to appear beneath icon names. You can set three information types, in the order that they appear.

Date

Configures the date format.

List Columns

To configure the columns that appear in the File Manager, as well as the order in which they appear, click Computer > Control Center > Look and Feel > File Management (or Edit > Preferences from Nautilus), then click the List Columns tab.

Select the columns that you want to appear. To change the order, click Move Up or Move Down.

Figure 2-24 File Manager List Columns Dialog Box

Preview

To configure how file previews appear in the File Manager and whether folders show the number of items they contain, click Computer > Control Center > Look and Feel > File Management (or Edit > Preferences from Nautilus), then click the Preview tab:

Figure 2-25 File Manager Preview Dialog Box

Select from the following options:

Table 2-13 File Manager Preview Options

Option

Description

Show text in icons

Specifies when to preview the content of text files in the icons that represent the files.

Show thumbnails

Specifies when to show thumbnails of image files in the icons that represent the files.

Only for files smaller than

Specifies the maximum file size for files represented by thumbnails.

Preview sound files

Specifies when to preview sound files.

Count number of items

Specifies when to show the number of files contained in folders. In the Icon view, you might need to increase your zoom level to see the number.

2.2.4 Locking Desktop Functions

The Lockdown Editor 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.

To start the Lockdown Editor, click Computer > Control Center > Look and Feel > Lockdown Editor.

You will see a window with a list of options on the left. Each option represents a different category of desktop settings that can be disabled.

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 have access to this configuration source, 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 don’t 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 GConf Configuration Sources in the GNOME Desktop System Administration Guide.

General

Use the options in the General category to disable printing, access to the command line, and saving to disk.

Figure 2-26 General Lockdown Editor Settings

Disable command line

Prevents the user from accessing the terminal or specifying a command line to be executed. This options also disables access to the panel's Run Application dialog box.

Disable printing

Prevents the user from printing. This option disables access to the Print dialogs boxes in all applications.

Disable print setup

Prevents the user from modifying print settings. This option disables access to the Print Setup dialog boxes in all applications.

Disable save to disk

Prevents the user from saving files to disk. This option disables access to the Save as dialog boxes in all applications.

Panel

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

Figure 2-27 Panel Lockdown Editor Settings

Lock down the panels

If this option is selected, the panel will not allow any changes to be made to the configuration of the panel. Individual applets might need to be locked down separately, however. The panel must be restarted for this to take effect.

Disable force quit

If this option is selected, the panel will not allow a user to force an application to quit (by removing access to the force quit button).

Disable lock screen

If this option is selected, the panel will not allow a user to lock their screen (by removing access to the lock screen menu entries).

Disable log out

If this option is selected, the panel will not allow a user to log out (by removing access to the log out menu entries).

Disable Applets

.Disables the applets selected in the list.

Epiphany Web Browser

Use the options in the Epiphany Web Browser category to control access to features in Epiphany.

Figure 2-28 Epiphany Web Browser Lockdown Editor Settings

Disable quit

Prevents the user from closing Epiphany.

Disable arbitrary URL

Prevents the user from typing a URL in Epiphany.

Disable bookmark editing

Prevents the user from adding or editing bookmarks.

Disable history

Disables all historical information by disabling back and forward navigation, not allowing the history dialog box, and hiding the most used bookmarks list.

Disable javascript chrome

Disables JavaScript's control over window chrome.

Disable toolbar editing

Prevents the user from editing toolbars.

Force fullscreen mode

Locks Epiphany in fullscreen mode.

Hide menubar

Hides the menubar by default. The menubar can still be accessed using F10.

Disable unsafe protocols

Disables loading of content from the unsafe protocols you specify. Safe protocols are http and https.

GNOME Screensaver

Use the options in the GNOME Screensaver category to lock the screen when the screensaver 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.

Figure 2-29 GNOME Screensaver Editor Settings

Lock on activation

Select this option to lock the screen when the screensaver goes active.

Allow log out

Select this option to offer an option in the unlock dialog box to log out after a delay.

Allow user switching

Select this option to offer an option in the unlock dialog box to switch to a different user.account.

2.2.5 Customizing the Main Menu

Use the Main Menu application to customize the GNOME Main menu. To start this application, click Computer > Control Center > Look and Feel > Main Menu.

NOTE: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.

This section contains the following information:

Editing the Main Menu

This section describes the following ways you can edit the Main menu:

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

NOTE:Some features, such as the ability to nest groups and insert separators, apply only if you use older versions of the GNOME menu.

Finding Menu Items

The Main Menu window is arranged with the Main menu submenus in the Menus list on the left and the items in the selected menu in the Items list 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.

Figure 2-30 Main Menu Editor

For example, to locate the Sound Recorder application:

  1. Click Computer > Control Center > Look and Feel > Main Menu.

  2. Click the arrow next to the Multimedia submenu in the Menus list, then select the Recording group.

  3. Locate Sound Recorder in the Items list.

Rearranging Menu Items

You can change the order in which items appear in the Main menu. 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.

To move an item, click it 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. You can also use the Move Up and Move Down buttons to change an item’s location in the menu.

Creating New Separators

Separators serve as visual cues to make it easier to find items in menus.

NOTE:Separators are not used in the current version of the GNOME menu. Adding a separator will have no effect. However, if you install and use an older version of the GNOME menu, you can use separators.

To create a separator:

  1. Click Computer > Control Center > Look and Feel > Main Menu.

  2. Select the item above the space where you want the separator to appear.

    For help locating an item, see Finding Menu Items.

  3. Click New Separator.

The new separator appears beneath the selected item in the Items list. You can drag the separator to a new location like you would any other menu item. To delete a separator, see Deleting Items from the Main Menu.

Showing or Hiding Menu Items

To show or hide an item:

  1. Click Computer > Control Center > Look and Feel > Main Menu.

  2. Locate the item in the Items list

  3. Select the box next to the item to show the item.

    or

    Deselect the box next to the item to hide the item.

  4. Click Close.

When you hide an item, it remains in the Items list and can be shown at another time if you decide you want it to appear in the menu. To delete an item from the Items list, see Deleting Items from the Main Menu.

Deleting Items from the Main Menu

There are two ways to remove an item from the Main menu:

  • To remove an item but retain it in the Items list so you can easily add it to the menu, hide the item as explained in Showing or Hiding Menu Items.

  • To delete an item from the Items list so it can no longer be shown, right-click the item and click Delete.

NOTE:Separators can not be hidden. They can only be added or deleted.

If you want to show a deleted item, you must add it like you would a new application. See Adding New Items to the Main Menu for information about adding an application.

Renaming Menu Items

  1. Click Computer > Control Center > Look and Feel > Main Menu.

  2. Locate the menu item whose name you want to change, as explained in Finding Menu Items.

  3. Right-click the item, then click Properties.

  4. Replace the current name with the name you want to give the item, then click Close.

The old name is replaced by the new one in the menu.

Changing an Item’s Generic Name

A short descriptive name appears beneath the name of each item in the Main menu. This is known as the generic name. To change the generic name:

  1. Click Computer > Control Center > Look and Feel > Main Menu.

  2. Locate the menu item whose generic name you want to change, as explained in Finding Menu Items.

  3. Right-click the item, then click Properties.

  4. Replace the current generic name with the generic name you want to give the item, then click Close.

The old generic name is replaced by the new one in the menu.

Adding New Items to the Main Menu

You can add a new item to the Main menu. This is especially 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.

To add an application to the Main menu:

  1. Click Computer > Control Center > Look and Feel > Main Menu.

  2. 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.

  3. Click New Item.

  4. Type a name and generic name for the item.

  5. Click Browse and browse to the item.

  6. Select the item.

  7. Click the Type list, then select the type of item.

    For example, if you are adding a directory, click the list and select Directory. If you are adding an application, leave the default item type, Application, as is.

  8. (Optional) To assign an icon to the new item, click No Icon, then select an icon for the item.

    If you do not select an icon, the item appears in the menu without an icon.

  9. Click Close.

After the item is added to the menu, you can move it to the place where you want it to appear in the menu, as described in Rearranging Menu Items.

2.2.6 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.

2.2.7 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 2-31 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.

2.2.8 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 titlebar, 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 2-32 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 logo key).