2.2. Customizing GNOME

Fedora's version of the GNOME desktop provides a convenient and attractive desktop environment, but by customizing it for the way you work you can increase your comfort and productivity.

2.2.1. How Do I Do That?

Almost all of the Fedora GNOME desktop, as well as desktop options that are not part of GNOME or KDE, can be configured using the SystemPreferences menu; other portions of the desktop can be configured by right-clicking on a GNOME component.

This lab looks at the GNOME settings most commonly used to customize the desktop.

Most GNOME settings take effect immediately; you do not need to click an Apply button for a change to take effect.

2.2.1.1. Customizing the desktop appearance using themes

The GNOME desktop and the Metacity window manager (the default GNOME window manager) use themes to configure appearance. Each theme is a combination of configuration information, images, and software that provides a particular visual effect and behavior.

Three types of component themes are used on the desktop:

Application (or control) themes

Configure the appearance of the controls: elements used by applications to build the graphical user interface, such as buttons, sliders, scrollbars, and text-entry fields.

Window border themes

Used by the Metacity window manager to control the appearance of the window borders, title bar, and title bar buttons.

Icons

Control the appearance of icons on the panel, desktop, application toolbars, and Nautilus file manager.

One component theme from each category can be combined into an overall desktop theme.

To change themes, select SystemPreferencesTheme from the panel menu. The window shown on the left of Figure 2-6 will appear.

Figure 2-6. Theme preferences tool

You can select a desktop theme from this list by clicking on it. The theme will start to load immediately, and the appearance of your desktop will change in a few seconds.

To create a custom combination of component themes, click the Theme Details button. The window shown on the right of Figure 2-6 will be displayed. There is a tab for each of the three component theme types. You can select a different theme for any of the components, and when you do, a Custom Theme entry will appear in the main Theme Preferences window. Your selection will take effect immediately so that you can preview the effect. Once you are satisfied with a combination of component themes, click on the Save Theme button to name the combination and save it as a desktop theme.

To install additional component themes, open a browser and go to http://art.gnome.org/, and open the Theme Preferences window in an adjacent part of the screen. When you find a theme on art.gnome.org that you wish to install, simply drag the download icon (a small floppy disk) from the browser window to the Theme Preferences window, and it will automatically be installed. You can then combine that component theme with others to produce a new desktop theme as described earlier.

2.2.1.2. Customizing the panels

Fedora's desktop is configured with two panels by default: one at the top of the screen containing the menus, icons, and applets, and one at the bottom of the screen containing the task list.

You can add another panel by right-clicking on an existing one and selecting New Panel. The new panel will appear on an edge of the screen that doesn't have a panel, or at the top of the screen if all of the edges are occupied. You can move it to another location by dragging it with the mouse.

To delete a panel, right-click on it and select "Delete this Panel." If there is anything on the panel, a confirmation dialog will appear before the panel is deleted.

To add items to a panel, right-click on the panel and select "Add to Panel." Although most of the options presented are applets or monitors, you can also add a drawer, which is like a panel that can be unfolded from another panel. A drawer is managed in the same way as a panel, by right-clicking on it.

To move an item around a panel, or move it to another panel, middle-click on the item and drag it (or right-click and use the Move menu option). To push along other icons, hold the shift key while dragging.

To delete an item from the panel, right-click on it and select "Remove from Panel."

To set a panel's properties, right-click it and select Properties. A small window will appear, containing two tabs, General and Background.

The General tab contains these settings:

Orientation

Selects one of the four screen edges for panel placement.

Size

Sets the panel size in pixels. 48 pixels is the default; the minimum size is 23 pixels, and the maximum is 120. Reducing this number will make the panel smaller and leave more screen space for your applications, while increasing this number will increase the panel size, making the icons bigger so that they are easier to see and click on. Experiment to find a value that works well for you; I find that 24 pixels is right for my eyes.

Expand

Selecting this checkbox makes the panel expand to fill the entire edge of the screen; deselecting it makes the panel just large enough to hold its contents.

Autohide

When selected, most of the panel will slide off the screen when not in contact with the mouse pointer, freeing up space for applications. To unhide the panel, place your mouse pointer over the part of the panel that is still visible.

Show hide buttons

Enables buttons at the end of the panel that can be clicked to make the panel slide off the screen (endwise). The "Arrows on Hide Buttons" checkbox will make the hide buttons bigger and add a graphical arrow to each one.

The Background tab lets you set the background color to the default for the current desktop theme, a solid color (which can have a pseudo-transparency effect applied using the Style slider), or a background image. This is almost always left at the default setting, which uses the desktop theme.

2.2.1.3. Customizing the desktop background

The menu option SystemPreferencesDesktop Background is used to adjust the desktop background color and imagebut most Fedora users get there using the shortcut of right-clicking on the desktop and selecting Change Desktop Background. Both methods cause the Desktop Background Preferences window to appear, shown in Figure 2-7.

Figure 2-7. Desktop Background Preferences window

You can change to any of the listed background images by clicking on it. To add your own image, drag and drop an image file from the Nautilus file manager, or click the Add Wallpaper button and enter the filename; to remove an image, highlight it and click the Remove button. If you don't want a background image, select the No Wallpaper option.

The Style control determines how the selected image will be displayed:

Centered

The image is placed, full-size, in the center of the screen. If it's smaller than the screen, the remaining space is filled with the desktop color; if it's larger than the screen, it is automatically cropped.

Fill Screen

The image is scaled in both the horizontal and vertical dimensions to fill the screen. This may result in some distortion of the image if its rectangular proportions (aspect ratio) don't match those of the screen.

Scaled

The image is scaled, keeping the original aspect ratio, until it fills the screen. Any remaining space is filled with the desktop color. For photographs, this is a better choice than Fill Screen.

Tiled

The image is placed in the upper-left corner of the screen and repeated as many times as necessary (both horizontally and vertically) to fill the screen.

The Desktop Colors control sets the desktop color style (solid, horizontal gradient, or vertical gradient) and the colors used for that style. The color or gradient selected here will fill any part of the background not covered by an image and will show through background images that have transparency.

2.2.1.4. Customizing the window manager's behavior

Select the menu option SystemPreferencesWindow to modify the behavior of the window manager, Metacity. Three options are presented in a window:

Select windows when the mouse moves over them

This behavior is called focus-follows-mouse and is very popular with some long-time users of the X Window System. Normally, you need to click on a window to give it focusin other words, the last window clicked is the window that receives keyboard input. If you select this checkbox, you can focus a window simply by placing your mouse pointer over it. This is convenient, but if your mouse pointer drifts to another window, you may end up typing into the wrong window.

If you select "focus-follows-mouse," then you can optionally configure the window manager to automatically raise focused windows after a brief pause, so that they are on top of other windows.

Titlebar Action

Configures the window manager to maximize or shade a window when the titlebar is double-clicked.

Movement Key

This setting selects the modifier key for moving windows. If you hold down the selected modifier and click on a window, you can drag it to a new location.

2.2.1.5. Customizing Nautilus

The Nautilus file manager is configured using the EditPreferences option in any Nautilus window, or through the panel menu option SystemPreferencesFile Management. A configuration window will appear with five tabs, containing lots of options.

Here are some common customizations for Nautilus:

• The appearance of folder contents can be separately configured for each folder using the Nautilus toolbar. To configure default settings, set the View New Folders Using and the Arrange Items options on the Views tab.

• To disable the spatial behavior of Nautilus, select the Behavior tab and select the "Always Open in Browser Windows" checkbox.

• To enable the direct deletion of files (instead of placing them in the trash, which requires the trash to be emptied before the disk space is freed up), select "Include a Delete Command that Bypasses Trash" on the Behavior tab. Right-clicking on a file will now expose both the normal "Move to Trash" option and a new Delete option.

2.2.1.6. Customizing keyboard shortcuts

Both mice and keyboards are effective input devicesbut switching between them can significantly slow you down. A good set of keyboard shortcuts enables you to perform common operations without switching to the mouse.

Fedora's GNOME configuration contains a good set of keyboard shortcuts. To change shortcuts or add new ones, select the menu option SystemPreferencesKeyboard Shortcuts, which displays the window shown in Figure 2-8.

Figure 2-8. GNOME Keyboard Shortcuts window

This window shows a number of actions on the desktop and the shortcut key for each. To change a shortcut, click on an entry. The shortcut for that entry will change to read New Accelerator. Press the key or key combination that you wish to use for that keyboard shortcut; if the shortcut is not already in use, it will be assigned to the selected action, and if it is in use, the conflict will be displayed in an error dialog.

To remove a keyboard shortcut, click on an entry, and then press Backspace.

If you have a "multimedia" keyboard with keys for sound control and common applications, you can in most cases use those keys as shortcuts. However, the Keyboard Shortcuts window will show these keys as hexadecimal codes, as shown in the highlighted line in Figure 2-8. Not all keys can be used as shortcuts because some multimedia keyboards are internally divided to act as two separate keyboards, with multimedia keys being sent to a different output. In a few rare cases, the multimedia keys don't generate normal keyboard scancodes at all.

2.2.2. How Does It Work?

GNOME stores most of its configuration in hidden directories in each user's home directory. Most configuration options and settings are stored, using the Gconf system, in XML files located in ~/.gconf.

Themes consist of a large number of files, stored in specific directories according to the type of theme and whether the theme is installed for personal use or system-wide use, as shown in Table 2-2. The GNOME theme configuration tools perform a personal installation of themes.

Table 2-2. Directories for themes and icons

Theme type	Personal installation	System-wide installation
Icon themes	~/.icons	/usr/share/icons/
Application/control and Window Manager themes	~/.themes	/usr/share/themes/

When a new user is created, the files and directories in /etc/skel are copied to the new user's home directory; you can include default configuration settings by placing them into that directory. For example, files in /etc/skel/.gconf are placed in ~/.gconf when a new account is created.

GNOME panels are managed by the gnome-panel program, and the desktop is managed by Nautilus.

2.2.3. What About...

2.2.3.1. ...making a theme available to all users?

After testing component themes, you can move them from your personal theme directories to the system-wide directories:

# mv /home/yourusername/.icons/* /usr/share/icons/
# mv /home/yourusername/.themes/* /usr/share/themes/
# chown -R root:root /usr/share/{icons,themes}
               

2.2.4. Where Can I Learn More?

• The GNOME desktop manual; press F1 in any GNOME application, select SystemHelp, or enter the command yelp.

• GNOME homepage: http://gnome.org

• freedesktop.org: http://freedesktop.org