This chapter describes how to use the preference tools to customize the GNOME Desktop. A preference tool is a small application that allows you to change settings in the GNOME Desktop. Each preference tool covers a particular aspect of your computer. For example, with the Mouse preference tool you can set your mouse to left-handed or right-handed use, or change the speed of the pointer on the screen. With the Windows preference tool you can set behaviour common to all windows such as the way in which you select them with the mouse. To open a preference tool, choose SystemPreferences in the top panel. Choose the tool that you require from the submenu. With a few exceptions, the changes you make to settings in a preference tool take effect immediately, without needing to close the preference tool. You can keep the preference tool window open while you try the changes, and make further changes if you wish. Some applications or system components may add their own preference tools to the menu. Some preference tools let you modify essential parts of your system, and therefore require administrative access. When you open the preference tool, a dialog box will prompt you for your password. These are in the SystemAdministration submenu. This menu also contains more complex utility applications for managing and updating your system. accessibility setting assistive technology preferences preference tools Assistive Technologies Use the Assistive Technologies preference tool to enable assistive technologies in the GNOME Desktop. You can also use the Assistive Technology preference tool to open other preference tools which contain preferences related to assistive technologies. Preferred Applications lets you specify assistive technology applications to start automatically when you log in. See Keyboard Accessibility lets you configure keyboard accessibility features such as sticky keys, slow keys or bounce keys. See Mouse Accessibility lets you configure mouse accessibility features such as dwell clicking. See lists the assistive technology preferences that you can modify. Dialog Element Description Enable assistive technologies Select this option to enable assistive technologies in the GNOME Desktop. Note that for technical reasons, you have to log in again after enabling this option for it to be fully effective. preference tools Keyboard Shortcuts shortcut keys configuring keyboard shortcuts configuring Use the Keyboard Shortcuts preference tool to customize the default keyboard shortcuts to your requirements. A keyboard shortcut is a key or combination of keys that provides an alternative to standard ways of performing an action. For more on keyboard shortcuts, and a list of the default shortcuts in GNOME, see . To edit a keyboard shortcut, perform the following steps: Click the action in the list. If you are using the the keyboard, use the arrow keys to select the shortcut and press Return. Press the new key or key combination you want to assign to the action. To clear a shortcut, press Backspace. The action is now marked as Disabled. To cancel assigning a shortcut, click elsewhere in the window or press Escape. The shortcuts you can customize are grouped as follows: Desktop These are general shortcuts for the whole desktop, such as logging out, locking the screen, opening the panel menubar, or launching a web browser. Sound Shortcuts for controlling your music player and the system volume. Window Management Shortcuts for working with windows and workspaces, such as maximizing or moving the current window, and switching to another workspace. For more information on these kinds of actions, see and . Accessibility Shortcuts for starting assistive technologies, such as a screen reader, a magnifier or an on-screen keyboard. Custom Shortcuts Custom shortcuts that have been added with the Add button. This section will not be shown if there are no custom shortcuts. To add a custom shortcut, use the Add button in the action area. You have to provide a name and a command for the new shortcut. The new custom shortcut will appear in the list of shortcuts and can be edited in the same way as the predefined shortcuts. To remove a custom shortcut, use the Remove button. preference tools Preferred Applications default applications preferred applications Use the Preferred Applications preference tool to specify the applications that you want the GNOME Desktop to use when the GNOME Desktop starts an application for you. For example, you can specify the web browser application (Epiphany , Mozilla Firefox, Opera ...) to launch when you click on a link in other applications such as email clients or document viewers. Preferred Applications can be found by going to SystemPreferencesPreferred Applications. You can customize the preferences for the Preferred Applications preference tool in the following functional areas. Internet (Web, Mail) Multimedia (Multimedia Player) System (Terminal) Accessibility (Visual, Mobility) For each preferred application category, a drop-down menu contains a list of possible applications you can choose from. The list depends on the applications installed on your computer. In each category, the last item in the menu (Custom) permits you to customize the command used by the system when the specific launch action occurs. preferred applications custom command The following table summarizes the various options you can choose from when you select Custom in the drop-down application menu. Dialog Element Description Command Enter the command to execute to start the custom application. For the Web Browser and the Mail Reader applications, you can include a %s after the command to tell the application to use the URL or Email address you clicked on. The exact command arguments may depend on the specific application. Run in terminal Select this option to run the command in a terminal window. Select this option for an application that does not create a window in which to run. Execute flag (Terminal only) Most terminal applications have an option that cause them to treat the remaining command line options as commands to run (-x for gnome-terminal). Enter this option here. For example, this is used when executing a command of a launcher for which the chosen type is Application in Terminal. Run at start (Accessibility only) Select this option to run the command as soon as your session begins. For more accessibility options, see GNOME Desktop Accessibility Guide. The Appearance preference tool lets you configure various aspects of how your desktop looks: Theme, Desktop Background, Fonts, User Interface. themes setting controls options themes setting window frame options themes setting icons options windows setting frame theme options preference tools Theme A theme is a group of coordinated settings that specifies the visual appearance of a part of the GNOME Desktop. You can choose themes to change the appearance of the GNOME Desktop. Use the Theme tabbed section to select a theme. You can choose from a list of available themes. The list of available themes includes several themes for users with accessibility requirements. A theme contains settings that affect different parts of the GNOME Desktop, as follows: Controls GTK+ themesthemes, controls optionsthemescontrols optionsintroductionThe controls setting for a theme determines the visual appearance of windows, panels, and applets. The controls setting 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 choose an option for the controls setting from the Controls tabbed section in the Customize Theme window. Colors themescolor optionsintroductioncolor themesthemes, color optionsThe color setting for a theme determines the color of various user interface elements. You can choose several pairs of colors from the Colors tabbed section in the Customize Theme window. It is important to choose pairs of colors that have a good contrast with each other, otherwise text may become hard to read. Window frame themeswindow frame optionsintroductionMetacity themesthemes, window frame optionsThe window frame setting for a theme determines the appearance of the frames around windows only. You can choose an option for the window frame setting from the Window Border tabbed section in the Customize Theme window. Icons themesicons optionsintroductionicon themesthemes, icons optionsThe icon setting for a theme determines the appearance of the icons on panels and the desktop background. You can choose an option for the icon setting from the Icons tabbed section in the Customize Theme window. Pointer themespointer optionsintroductionpointer themesthemes, pointer optionsThe pointer setting for a theme determines the appearance of and sice of the mouse pointer. You can choose an options for the pointer setting fromthe Pointer tabbed section in the Customize Theme window. The themes that are listed in the Theme tabbed section are different combinations of controls options, window frame options, and icon options. You can create a custom theme that uses different combinations of controls options, window frame options, and icon options. To create a custom theme, perform the following steps: Start the Appearance preference tool. Open the Theme tabbed section. Select a theme in the list of themes. Click on the Customize button. A Customize Theme dialog is displayed. Select the controls option that you want to use in the custom theme from the list in the Controls tabbed section. The list of available controls options includes several options for users with accessibility requirements. Click on the Window Border tab to display the Window Border tabbed section. Select the window frame option that you want to use in the custom theme from the list of available options. The list of available window frame options includes several options for users with accessibility requirements. Click on the Icons tab to display the Icons tabbed section. Select the icons option that you want to use in the custom theme from the list of available options. The list of available icons options includes several options for users with accessibility requirements. Click Close to close the Customize Theme dialog. On the Appearance preferences tool, click on the Save As button. A Save Theme As dialog is displayed. 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. You can add a theme to the list of available themes. The new theme must be an archive file that is tarred and zipped. That is, the new theme must be a .tar.gz file. To install a new theme, perform the following steps: Start the Appearance preference tool. Open the Theme tabbed section. Click on the Install button. A file chooser dialog is displayed. Enter the location of the theme archive file in the location entry. Alternatively, select the theme archive file in the file list. When you have selected the file, click Open. Click on the Install button to install the new theme. You can delete controls options, window frame options, or icons options. To delete a controls option, window frame option, or icons option, perform the following steps: Start the Appearance preference tool. Open the Theme tabbed section. Click on the Customize button. A Customize Theme dialog is displayed. Click on the tab for the type of option that you want to delete. Select the theme option you want to delete. Use the Delete button to delete the selected option. Note that you can not delete system-wide theme options. desktop customizing background GNOME Desktop preference tools preference tools preference tools Background backgrounds customizing desktop background The desktop background is the image or color that is applied to your desktop. You can open Background tabbed section in the Appearance preference tool by right-clicking on the desktop and choosing Change Desktop Background, as well as from the SystemPreferences menu. 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. You can also drag a color or a pattern to the desktop from the Backgrounds and Emblems dialog in the Nautilus file manager. lists the background preferences that you can modify. Dialog Element Description Desktop Background Choose an image from the list. Alternately, you can use the Add button to choose any image on your computer. Style 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, respecting the image's original size. Fill Screen: Enlarges the image to cover the desktop, altering its proportions if needed. Scaled: Enlarges the image until the image meets the screen edges, and maintains the proportions of the image. Zoom: Enlarges the smaller dimension of the image until it meets the screen edges; the image may be cropped in the other dimension. Tiled: Duplicates the original-sized image as often as necessary and print the images next to another so as they entirely cover the desktop. Add Click on the Add to browse for an image on your computer. A standard file selector will be presented. Choose the image you want and click Open. Remove Choose the image that you want to remove, then click Remove. This removes the image from the list of available wallpapers; however, it does not delete the image from your computer. Colors To specify a color scheme, use the options in the Style drop-down list, and the color selector buttons. You can specify a color scheme in one of the following ways: Choose Solid color from the Background Style drop-down list to specify a single color for the desktop background. To choose the color that you require, click on the Color button. The Pick a Color dialog is displayed. Choose a color, then click OK. Choose Horizontal gradient from the Background Style drop-down list. This option creates a gradient effect from the left screen edge to the right screen edge. Click on the Left Color button to display the Pick a Color dialog. Choose the color that you want to appear at the left edge. Click on the Right Color button. Choose the color that you want to appear at the right edge. Choose Vertical gradient from the Background Style drop-down list. This creates a gradient effect from the top screen edge to the bottom screen edge. Click on the Top Color button to display the Pick a Color dialog. Choose the color that you want to appear at the top edge. Click on the Bottom Color button. Choose the color that you want to appear at the bottom edge. preference tools Font fonts desktop fonts applications fonts window title fonts terminal fonts rendering Use the Fonts tabbed section in the Appearance preference tool to choose which fonts are used in different parts of the desktop, and the way in which fonts are displayed on the screen. The font selector button shows the name of the font and its point size. The name is also shown in bold, italic, or regular type. To change the font, click the font selector button. The font picker dialog opens. Select the font family, style, and point size from the lists. The preview area shows your current choice. Click OK to accept the change and update the desktop. You can choose fonts for the following parts of the desktop: Application font This font is used in the menus, toolbars, and dialog boxes of applications. Document font This font is used to display documents in applications. In some applications, you can override this choice in the application's preferences dialog. Desktop font This font is used in icon labels on the desktop. Window title font This font is used in the titlebars of windows. Fixed width font This font is used in the Terminal application and applications to do with programming. You can set the following options relating to how fonts are displayed on the screen: Rendering 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 also 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. Details Click on this button 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: Hinting is a font-rendering technique that improves the quality of fonts at small sizes and an at low screen resolutions. Select one of the options to specify how to apply hinting your fonts. 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. toolbars, customizing appearance preference tools Menus & Toolbars menus in applications, customizing appearance You can use the Interface tabbed section in the Appearance preference tool to customize the appearance of menus, menubars, and toolbars for applications that are part of GNOME. As you make changes to the settings, the preview display in the window updates. This allows you to see the changes if no application windows are currently open. Show icons in menus Select this option to display an icon beside items in application menus and the panel menu. Not all menu items have an icon. Editable menu shortcut keys Selecting this option allows you to define new keyboard shortcuts for menu items. To change an application shortcut key, open the menu, and with the mouse pointer on the menu item you wish to change, press the new combination of keys. To remove a shortcut key, press Backspace or Delete. When using this feature, you will not be warned if assigning a new shortcut key to a command also removes it from another command. There is no way to restore the original, default keyboard shortcut for a command. This feature does not maintain shortcuts that are normally common to all applications, such as CtrlC for Copy. This may lead to inconsistencies in your GNOME applications. Toolbar button labels Choose one of the following options to specify what to display on the toolbars in your GNOME-compliant applications: Text Below Icons: Select this option to display toolbars with text as well as an icon on each button. Text Beside Icons: Select this option to display toolbars with an icon only on each button, and with text on the most important buttons. Icons Only: Select this option to display toolbars with an icon only on each button. Text Only: Select this option to display toolbars with text only on each button. window manager customizing preference tools Windows Use the Windows preference tool to customize window behavior for the GNOME Desktop. lists the windows preferences that you can modify. Dialog Element Description Select windows when the mouse moves over them Select this option to give focus to a window when you point to the window. The window retains focus until you point to another window. Raise selected windows after an interval Select this option to raise windows a short time after the window receives focus. Interval before raising Specify the interval to wait before raising a window that has received focus. Double-click titlebar to perform this action Select the behavior that you want to occur when you double-click on a window titlebar. Select one of the following options: Maximize: Maximizes the window. Maximize Vertically: Maximizes the window vertically without changing its width. Maximize Horizontally: Maximizes the window horizontally without changing its height. Minimize: Minimizes the window. Roll up: Roll up the window. None: Do nothing. If a window is already maximized or rolled up, double-clicking on the titlebar will return it to its normal state. To move a window, press-and-hold this key then grab the window Select the key to press-and-hold when you drag a window to move the window. The position of the Control, Alt and Super keys on the keyboard can be modified in the Keyboard Layout Options dialog, see . preference tools screensaver A screensaver displays moving images on your screen when your computer is not being used. Screensavers also help prevent older monitors being damaged by the same image being displayed for long periods of time. To stop the screensaver and return to the desktop, move the mouse or press a key on the keyboard. Use the Screensaver preference tool to set the type of screensaver, the time before the screensaver starts, and whether to require a password to return to the desktop. You can modify the following settings: Screensaver Select the Screensaver theme from the list. A reduced version of the selected screensaver theme is shown. Press Preview to show the selected theme on the whole screen. During preview, use the arrow buttons at the top of the screen to go through the list of screensaver themes. The Blank screen theme displays no image and only shows a black screen. The Random theme selects a screensaver to display from the list at random. Which screensavers are shown in the remainder of the list depends on your distributor or vendor. Regard the computer as idle after... Your computer becomes idle after this amount of time has passed with no input from you, such as moving the mouse or typing. This may affect power management (the monitor may power down for example) or instant messaging (chat applications may set your status as "away"). Use the slider to set the length of time in minutes or hours. Activate screensaver when computer is idle Select this option to have the screensaver start after the set length of time. Lock screen when screensaver is active When this option is selected, the screensaver will prompt you for your password when you try to return to the desktop. For more on locking your screen, see . The Network Settings allows you to specify the way your system connects to other computers and to internet. You will be prompted for the administrator password when you start Network Settings. This is because the changes done with this tool will affect the whole system. The Network Settings main window contains four tabbed sections: Connections Shows all network interfaces, it also allows you to modify their settings. General Allows you to modify your system host name and domain name. DNS Contains two sections, the DNS servers are what your computer use for resolving the IP addresses from the domain names. The search domains are the default domains in which your system will search any host when no domain is specified. Hosts Shows the list of aliases for accessing other computers. In the Connections section, select the interface you want to modify and press the Properties button, depending on the interface type you will be able to modify different data. Ethernet and IRLAN interfaces You can modify the way the interface is configured (DHCP or manually), if the interface is configured manually, you can also modify the interface IP address, netmask and gateway. Wireless interfaces You can modify the way the interface is configured (DHCP or manually), if the interface is configured manually, you can also modify the interface IP address, netmask and gateway, you can also modify the network name (ESSID) for this interface. Parallel line interfaces You can modify the interface IP address, as well as the remote IP address. PPP/Modem interfaces You can modify the modem device, whether you want it to dial using tones or pulses, the modem volume, the phone number, the username and password that your ISP provided and other advanced settings for PPP. In the Connections section, enable or disable the checkbox beside the interface. In the General section, change the hostname or domain name text boxes. In the DNS Servers section, press the Add button and fill in the new list row with the new domain name server. In the DNS Servers section, select a DNS IP address from the list and press the Delete button. In the Search Domains section, press the Add button and fill in the new list row with the new search domain. In the Search Domains section, select a search domain from the list and press the Delete button. In the Hosts section, press the Add button and type an IP address and the aliases that will point to in the window that pops up. In the Hosts section, select an alias, press the Properties button from the list and modify the alias settings in the window that pops up. In the Hosts section, select an alias from the list and press the Delete button. Press the Add button besides the Locations menu, specify the location name in the window that pops up. Press the Remove button besides the Locations menu, the selected profile will be deleted. Select one location from the Locations menu, all the configuration will be switched automatically to the chosen location. preference tools Network Proxy network proxy setting preferences Internet configuring connection proxy setting preferences The Network Proxy Preferences enables you to configure how your system connects to the Internet. You can configure the GNOME Desktop to connect to a proxy server, and specify the details of the proxy server. A proxy server is a server that intercepts requests to another server, and fulfills the request itself, if it can. You can enter the domain name or the Internet Protocol (IP) address of the proxy server. A domain name is a unique alphabetic identifier for a computer on a network. An IP address is a unique numeric identifier for a computer on a network. Why would one want to use a proxy? This description makes it sounds like it's a user preference, rather than being dictated by the network you're on. We should make this more clear. Since it is possible that you need to use a different proxy configuration in different places, Network Proxy Preferences allows you to define separate proxy configurations and switch between them using the Location drop-down box at the top of the window. Choose New Location to create a proxy configuration for a new location. Locations can be removed using the Delete Location button at the bottom of the window. Direct internet connection Select this option to connect to the Internet without a proxy server. Manual proxy configuration Select this option to connect to the Internet through a proxy server and configure the proxy settings manually. HTTP proxy Enter the domain name or IP address of the proxy server to use when you request an HTTP service. Enter the port number of the HTTP service on the proxy server in the Port field. If the HTTP proxy server requires authentication, click the Details button to enter your username and password. Secure HTTP proxy Enter the domain name or IP address of the proxy server to use when you request a secure HTTP service. Enter the port number of the secure HTTP service on the proxy server in the Port field. FTP proxy Enter the domain name or IP address of the proxy server to use when you request an FTP service. Enter the port number of the FTP service on the proxy server in the Port field. Socks host Enter the domain name or IP address of the Socks host to use. Enter the port number for the Socks protocol on the proxy server in the Port field. Automatic proxy configurationSelect this option if you want to connect to the Internet through a proxy server, and you want to configure the proxy server automatically. Automatic proxy configuration works by means of a so-called PAC file, which your browser downloads from a web server. If you don't specify the URL for a PAC file in the Autoconfiguration URL entry, your browser will try to locate one automatically. Autoconfiguration URLEnter the URL of a PAC file that contains the information required to configure the proxy server automatically. Set which hosts should not use the proxy in the Ignore Host List in the Ignored Hosts tabbed section. When you access these hosts, you will connect to the Internet directly without a proxy. setting session sharing preferences The Remote Desktop preference tool enables you to share a GNOME Desktop session between multiple users, and to set session-sharing preferences. lists the session-sharing preferences that you can set. These preferences have a direct impact on the security of your system. Dialog Element Description Allow other users to view your desktop Select this option to enable remote users to view your session. All keyboard, pointer, and clipboard events from the remote user are ignored. Allow other users to control your desktop Select this option to enable other to access and control your session from a remote location. When a user tries to view or control your desktop Select the following security considerations when a user tries to view or control your session:Ask you for confirmation: Select this option if you want remote users to ask you for confirmation when they want to share your session. This option enables you to be aware of other users who connect to your session. You can also decide what time is suitable for the remote user to connect to your session.Require the user to enter this password: Select this option to authenticate the remote user if authentication is used. This option provides an extra level of security. Password Enter the password that the client who attempts to view or control your session must enter. preference tools Keyboard keyboard configuring general preferences Use the Keyboard preference tool to modify the autorepeat preferences for your keyboard, and to configure typing break settings. To open the Keyboard Accessibility preference tool, click the Accessibility button. Use the General tabbed section to set general keyboard preferences. lists the keyboard preferences that you can modify. Dialog Element Description Key presses repeat when key is held down Select this option to enable keyboard repeat. If keyboard repeat is enabled, when you press-and-hold a key, the action associated with the key is performed repeatedly. For example, if you press-and-hold a character key, the character is typed repeatedly. Delay Select the delay from the time you press a key to the time that the action repeats. Speed Select the speed at which the action is repeated. Cursor blinks in text boxes and fields Select this option to enable the cursor to blink in fields and text boxes. Speed Use the slider to specify the speed at which the cursor blinks in fields and text boxes. Type to test settings The test area is an interactive interface so you can see how the keyboard settings affect the display as you type. Type text in the test area to test the effect of your settings. Use the Layouts tabbed section to set your keyboard's language, and also the make and model of keyboard you are using. This will allow GNOME to make use of special media keys on your keyboard, and to show the correct characters for your keyboard's language. Keyboard model Use the browse button (labelled with the currently selected keyboard model) to choose another keyboard make and model. Separate layout for each window When this option is selected, each window has its own keyboard layout. Changing to a different layout will only affect the current window. This allows you to to type with a Russian keyboard layout in a word processor, then switch to your web browser and type with an English keyboard layout, for example. Selected Layouts You can switch between selected layouts to change the characters your keyboard produces when you type. To add a layout, click Add. You can have up to four layouts. To remove a layout, select it and press Remove. To switch between keyboard layouts, use the Keyboard Indicator panel applet. To add a layout to the list of selected layouts, click the Add button. It opens a layout chooser dialog, which lets you select a layout by country or by language. Click Reset to Defaults to restore all keyboard layout settings to their initial state for your system and locale. Click the Layout Options button to open the Keyboard Layout Options dialog. The Keyboard Layout Options dialog has options for the behaviour of keyboard modifier keys and certain shortcut options. Expand each group label to show the available options. A label in boldface indicates that the options in the group have been changed from the default setting. The options shown in this dialog depend on the X windowing system you are using. Not all the following options might be listed on your system, and not all the options shown might work on your system. Adding the EuroSign to certain keys Use these options to add the Euro currency symbol € to a key as a third-level character. To access this symbol, you must assign a third level chooser. Alt/Win key behavior This group of options allows you to assign the behaviour of Unix modifier keys Super, Meta, and Hyper to the Alt and Windows keys on your keyboard. CapsLock key behavior This group has several options for the Caps Lock key. Compose key position The Compose key allows you to combine two keypresses to make a single character. This is used to create an accented character that might not be on your keyboard layout. For example, press the Compose key, then ', then e to obtain e-acute character. Control key position Use this group of options to set the location of the Ctrl key to match the layout on older keyboards. Group Shift/Lock behavior Select keys or key combinations to switch your keyboard layout when pressed. Miscellaneous compatibility options Shift with numpad keys works as in MS Windows. With this option selected, using Shift with keys on the numerical pad when NumLock is off extends the current selection. With this option unselected, use Shift with keys on the numerical pad to obtain the reverse of the current behaviour for that key. For example, when NumLock is off, the 8 key acts as an up-arrow. Press Shift8 to type an '8'. Special keys (Ctrl+Alt+<key>) handled in a server. Select this option to have certain keyboard shortcuts passed to the X windowing system instead of being handled by GNOME. Third level choosers A third level key allows you to obtain a third character from a key, in the same way that pressing Shift with a key produces a different character to pressing the key alone. Use this group to select a key you want to act as a third level modifier key. Pressing the third-level key and Shift produces a fourth character from a key. The third and fourth level characters for your keyboard layout are shown in the Keyboard Indicator Layout View Window. Use keyboard LED to show alternative group. Use this option to specify that one of the light indicators on your keyboard should indicate when an alternative keyboard layout is in use. The selected keyboard light will no longer indicate its standard function. For example, the Caps Lock light will not react to the Caps Lock key. AccessX preference tools, Keyboard Accessibility keyboard configuring accessibility options accessibility configuring keyboard preference tools Keyboard Accessibility The Accessibility tabbed section allows you to set options such as filtering out accidental keypresses and using shortcut keys without having to hold down several keys at once. These features are also known as AccessX. This section describes each of the preferences you can set. For a more task-oriented description of keyboard accessibility, see the GNOME Desktop Accessibility Guide. lists the accessibility preferences that you can modify. Dialog Element Description Accessibility features can be toggled with keyboard shortcuts Select this option to show an icon in the notification area that offers quick access to accessibility features. Simulate simultaneous keypresses accessibility sticky keys Select this option to perform multiple simultaneous keypress operations by pressing the keys in sequence. Alternatively, to enable the sticky keys feature, press Shift five times. Disable sticky keys if two keys are pressed together Select this option to specify that when you press two keys simultaneously, you can no longer press keys in sequence to perform multiple simultaneous keypresses. Only accept long keypresses accessibility slow keys Select this option to control the period of time that you must press-and-hold a key before acceptance. Alternatively, to enable the slow keys feature, press-and-hold Shift for eight seconds. Delay Use the slider to specify the period of time that you must press-and-hold a key before acceptance. Ignore fast duplicate keypresses accessibility bounce keys Select this option to accept a key input and to control the key repeat characteristics of the keyboard. Delay Use the slider to specify the interval to wait after the first keypress before the automatic repeat of a pressed key. Type to test settings The test area is an interactive interface so you can see how the keyboard settings affect the display as you type. Type text in the test area to test the effect of your settings. To configure audio feedback for keyboard accessibility features, click the Audio Feedback button. It opens the Keyboard Accessibility Audio Feedback window. Configure audio feedback for keyboard accessibility features. lists the audio feedback preferences that you can modify. Dialog Element Description Beep when accessibility features are turned on or off Select this option for an audible indication when a feature such as sticky keys or slow keys is activated, or deactivated. Beep when a toggle key is pressed accessibility toggle keys Select this option for an audible indication of a toggle keypress. You hear one beep when a toggle key is turned on. You hear two beeps when a toggle key is turned off. Beep when a modifier key is pressed Select this option for an audible indication when you press a modifier key. Beep when a key is pressed Select this option for an audible indication when a key is pressed. Beep when a key is accepted Select this option for an audible indication when a key is accepted. Beep when a key is rejected Select this option for an audible indication when a key is rejected. The options in the Mouse Keys tabbed section let you configure the keyboard as a substitute for the mouse. lists the mouse keys preferences that you can modify. Dialog Element Description Pointer can be controlled using the keypad accessibility mouse keys Select this option to make the numeric keypad emulate mouse actions. The list of keys and their equivalences is in the GNOME Desktop Accessibility Guide under the heading To Enable the Keyboard to Emulate the Mouse. Acceleration Use the slider to specify how long it takes the pointer to accelerate to maximum speed. Speed Use the slider to specify the maximum speed that the pointer moves across the screen. Delay Use the slider to specify the period of time that must pass after a keypress before the pointer moves. Configure the Typing Break Preferences to make GNOME remind you to rest after you have been using the keyboard and mouse for a long time. During a Typing Break, the screen will be locked. lists the typing break preferences that you can modify. Dialog Element Description Lock screen to enforce typing break Select this option to lock the screen when you are due a typing break. Work interval lasts Use the spin box to specify how long you can work before a typing break occurs. Break interval lasts Use the spin box to specify the length of your typing breaks. Allow postponing of breaks Select this option if you want to be able to postpone typing breaks. If you stop using the keyboard and mouse for a length of time equal to the Break interval setting, the current work interval will be reset. preference tools Mouse mouse configuring With the Mouse preference tool you can: configure your mouse for right-hand use or for left-hand use, specify the speed and sensitivity of mouse movement, configure mouse accessibility features. Use the General tabbed section to specify whether the mouse buttons are configured for left-hand or right-hand use and configure the speed and sensitivity of your mouse. lists the general mouse preferences that you can modify. Dialog Element Description Right-handed Select this option to configure your mouse for right-hand use. When you configure your mouse for right-hand use, the left mouse button is the primary button and the right mouse button is the secondary button. Left-handed Select this option to configure your mouse for left-hand use. When you configure your mouse for left-hand use, the functions of the left mouse button and the right mouse button are swapped. Show position of pointer when the Control key is pressed Select this option to enable a mouse pointer animation when you press and release the Control key. This feature can assist you to locate the mouse pointer. The position of the Control key on the keyboard can be modified in the Keyboard Layout Options dialog, see . Acceleration Use the slider to specify the speed at which your mouse pointer moves on your screen when you move your mouse. Sensitivity Use the slider to specify how sensitive your mouse pointer is to movements of your mouse. Threshold Use the slider to specify the distance that you must move an item before the move action is interpreted as a drag-and-drop action. Timeout Use the slider to specify the amount of time that can pass between clicks when you double-click. If the interval between the first and second clicks exceeds the time that is specified here, the action is not interpreted as a double-click. Use the light bulb icon to check double-click sensitivity: the light will light up briefly for a click, but stay lit for a double-click. Use the Accessibility tabbed section to configure accessibility features that can help people who have difficulty with exact positioning of the pointer or with pressing the mouse buttons: Open a contextual menu by clicking and holding the primary mouse button; this is useful for users that can manipulate only one button. Perform different types of mouse button click by software; this useful for users that are not able to manipulate any buttons. The types of click that can be performed are: Single click A single click of the primary mouse button Double click A double click of the primary mouse button Drag click A click that begins a drag operation Secondary click A single click of the secondary mouse button lists the mouse accessibility preferences that you can modify: Dialog Element Description Trigger secondary click by holding down the primary button Select this option to enable simulated secondary clicks by pressing the primary mouse button for an extended time. Delay slider in the Simulated Secondary Click section Use the slider to specify how long the primary button must be pressed to simulate a secondary click. Initiate click when stopping pointer movement Select this option to enable automatic clicks when the mouse stops. Use the additional preferences in the Dwell Click section to configure how the type of click is chosen. Delay slider in the Dwell Click section Use the slider to specify how long the pointer must remain at rest before an automatic click will be triggered. Motion threshold slider Use the slider to specify how much the pointer may move to still be considered at rest. Choose type of click beforehand Select this option to pick the type of click to perform from a window or panel applet. Show click type window When this option is enabled, the different types of click (single click, double click, drag click or secondary click) can be selected in a window. The Dwell Click panel applet can be used instead of the window. Choose type of click with mouse gestures Select this option to pick the type of click by moving the mouse in a certain direction. The four combo boxes below this option allow to assign directions to the different types of click. Note that each direction can be used only for one type of click. Single click Choose the direction to trigger a single click. Dpuble click Choose the direction to trigger a double click. Drag click Choose the direction to trigger a drag click. Secondary click Choose the direction to trigger a secondary click. preference tools Display Use the Display preference tool to configure the monitors that your computer uses. On most laptop keyboards, you can use the key combination FnF7 to cycle between several typical monitor configurations without starting the Display preference tool. You can drag and move the graphical representations of the monitors in the upper part of the window to arrange how they are connected to form your desktop area. Note that the application displays small 'stickers' in the top left corner of each monitor to help you identify which rectangle corresponds to which monitor. In contrast to most other preference tools, changes you make in the Display preference tool don't take effect until you click the Apply button, and will revert to their previous settings unless you confirm the changes. This is a precaution to prevent bad display settings from rendering your computer unusable. lists the display preferences that you can modify for the currently selected monitor. The currently selected monitor is the one whose graphical representation has a bold black outline. It is also indicated by the background color of the section label. Dialog Element Description Mirror Screens Select this option to have all monitors show the whole desktop. Detect Monitors Use this button to make your desktop notice newly plugged in or unplugged monitors. This is necessary, since it would cost too much energy to constantly check for these changes. Resolution Select the resolution to use for the currently selected monitor from the drop-down list. Resolution refers to the pixel dimensions of the screen. A larger resolution means that more things fit on the screen, but everything will be smaller. Refresh rate Select the refresh rate to use for the currently selected monitor from the drop-down list. The refresh rate determines how often the computer redraws the screen. A too low refresh rate (below 60) makes the monitor flicker and can cause discomfort to your eyes. This is less of a problem on lcd displays. Rotation Select the rotation for the currently selected monitor. This option may not be supported on all graphics cards. Show displays in panel Select this option to show an icon in the notification area that allows you to quickly change the rotation. preference tools Sound sound setting preferences sound associating events with sounds events, associating sounds with volume The Sound preference tool enables you to control devices and volume for sound input and output. You can also specify which sounds to play when particular events occur. You can customize the settings for the Sound preference tool in the following functional areas: Sound Events Input Output You can chance the overall output volume using the Output volume slider at the top of the window. The Mute checkbox allows to temporarily suppress all output without disturbing the current volume. A sound theme is collection of sound effects that are associated to various events, such as opening a dialog, clicking a button or selecting an item in a menu. One of the most prominent event sounds is the System Bell sound that often played to indicate a keyboard input error. Use the Sound Effects tabbed section of the Sound preference tool to choose a sound theme and modify the bell sound lists the sound effects preferences that you can modify. Dialog Element Description Alert Volume slider Use the Alert Volume slider to control the volume for event sounds. The Mute checkbox allows to temporarily suppress event sounds without modifying the current volume. Sound Theme Use this combobox to select a different sound theme. Choose No sounds to turn off all event sounds. Choose an alert sound list Choose an alternative sound for the System Bell from this list. Selecting a list element plays the sound. Enable window and button sounds checkbox Uncheck this option if you don't want to hear sounds for window-related events (such as a dialog or a menu appearing) and button clicks. Use the Input tabbed section to set your preferences for sound input. lists the sound input preferences that you can modify. Dialog Element Description Input volume slider Use the input volume slider to control the input level. The Mute checkbox allows to temporarily suppress all input without disturbing the current input level. Input level The Input level display provides visual feedback that helps to select a suitable input volume Choose a device for sound input list Choose the device that you want to receive sound input from. Note that the input volume can also be controlled with the microphone icon that is shown in the notification area of the panel when an application is listening for sound input. Use the Output tabbed section to set your preferences for sound output. lists the sound output preferences that you can modify. Dialog Element Description Output volume slider Use the output volume slider to control the overall output volume. The Mute checkbox allows to temporarily suppress all output without disturbing the current volume. Note that the Output volume slider is located above the tabbed section at the top of the window. Choose a device for sound output list Choose the device that you want to hear sound output from. Balance slider Use the Balance slider to control the left/right balance of an output device that has more than one channel (e.g. stereo or 5.1). Note that the output volume can also be controlled with the speaker icon that is shown in the notification area of the panel. Use the Applications tabbed section to control the volume of sound played by individual applications. Each application that is currently playing sound is identified by its name and icon. See the GStreamer Properties Manual. preference tools Sessions sessions preferences startup applications customizing The Sessions preference tool enables you to manage your sessions. You can set session preferences, and specify which applications to start when you start a session. You can configure sessions to save the state of applications in the GNOME Desktop, and to restore the state when you start another session. You can also use this preference tool to manage multiple GNOME sessions. You can customize the settings for sessions and startup applications in the following functional areas: Session Options Startup Programs sessions setting options Use the Session Options tabbed section to manage multiple sessions, and to set preferences for the current session. lists the session options that you can modify. Dialog Element Description Automatically remember running applications when logging out startup applications session-managed Select this option if you want the session manager to save the state of your session when logging out. The session manager saves the session-managed applications that are open, and the settings associated with the session-managed applications when you log out. The next time that you start a session, the applications start automatically, with the saved settings. Remember currently running applications startup applications session-managed Select this option if you want the session manager to save the current state of your session. The session manager saves the session-managed applications that are open, and the settings associated with the session-managed applications. The next time that you start a session, the applications start automatically, with the saved settings. startup applications non-session-managed Use the Startup Programs tabbed section of the Sessions preference tool to specify non-session-managed startup applications. Startup applications are applications that start automatically when you start a session. You specify the commands that run the non-session-managed applications in the Startup Programs tabbed section. The commands execute automatically when you log in. You can also start session-managed applications automatically. For more information, see . lists the startup applications preferences that you can modify. Dialog Element Description Additional startup programs Use this table to manage non-session-managed startup applications as follows: To add a startup application, click on the Add button. The New Startup Program dialog is displayed. Enter the name of the appplication in the Name field. Then enter the command to start the application in the Command field. you can also specify a comment in the Comment field To edit a startup application, select the startup application, then click on the Edit button. The Edit Startup Program dialog is displayed. Use the dialog to modify the command and the startup order for the startup application. To delete a startup application, select the startup application, then click on the Remove button.