# Customizing Menus

The information in this chapter describes how GNOME implements menus and how you can customize menus.

## Introduction to Menus

The way in which GNOME implements menus in the desktop enables you to do the following:

- Customize the menu hierarchy easily. The menu hierarchy is not based on the file system hierarchy. You can edit a small number of files to customize the menu hierarchy. You do not need to modify your applications or move files.

- Install applications easily. You do not need to provide information about the menu hierarchy to applications when you install the applications.

- Configure menus so that users cannot modify the menus.

Menus in the GNOME desktop use the following components:

- File abstraction layer

- Vfolders

- Desktop entry files

- Directory entry files

## File Abstraction Layer

The `gnome-vfs` file abstraction layer provides a simplified and generalized way for applications to interact with files. The file abstraction layer also provides Uniform Resource Identifier (URI) locations that map to particular menu configuration files. To add a menu or a menu item for all users, you must add the menu or menu item to one of the URI locations. lists the menus to which you can add items, and the URI locations that correspond to the menus.

### Menus and URI Locations

Menu | URI Locations
--- | ---
Applications menu for all users | `applications-all-users:///`
Desktop Preferences menu for all users | `preferences-all-users:///`

## Vfolders

In general terms, a vfolder is a virtual representation of items that reside in a physical location or physical locations on your system. For example, a vfolder might represent the contents of several directories. A vfolder is an abstraction from one or more physical locations. In terms of menus in the GNOME desktop, a vfolder is a representation in a menu of items that might be physically located in several directories.

A vfolder information file is an XML file that describes a vfolder. Vfolder information files specify the structure of your menus. Vfolder information files specify the names of your menus, and the order in which applications appear in your menus. Vfolder information files have a `.vfolder-info` file extension.

The following is an excerpt from a vfolder information file:

    <?xml version="1.0"?>
    <VFolderInfo>
    .
    .
    .
      <Folder>
        <Name>Applications</Name>
        <Desktop>Applications.directory</Desktop>
        <Folder>
          <Name>Accessories</Name>
          <DontShowIfEmpty/>
          <Desktop>Accessories.directory</Desktop>
          <Query>
            <And>
              <Keyword>Application</Keyword>
              <Keyword>Utility</Keyword>
            </And>
          </Query>
        </Folder>
    .
    .
    .
      </Folder>
    </VFolderInfo>

describes some of the elements in vfolder information files.

### Vfolder Information File Elements

Element | Description
--- | ---
`<Folder>` | Contains the elements that define the name, content, and structure of the menu.
`<Name>` | Specifies the name of the menu.
`<Desktop>` | Specifies the name of the directory entry file that specifies the name, comment, and icon for the menu.
`<Query>` | Specifies a query to run on desktop entry files. If a desktop entry file matches the requirements in the query, the menu item is displayed in the menu. The query in the excerpt searches for desktop entry files that contain the keywords `Application` and `Utility` in the `Categories` key. Desktop entry files that match are displayed in the Applications menu. This element is optional.
`<DontShowIfEmpty/>` | If this element is present, the menu is not displayed if the menu does not contain any items. This element is optional.

## Desktop Entry Files

A desktop entry file is a data file that provides information about an item in a menu. The desktop entry file specifies the details for the item such as a name, a command to run, an icon, and so on. The desktop entry file also contains keywords which determine the location of the item in the menu hierarchy. Desktop entry files have a `.desktop` file extension.

The following is a sample desktop entry file:

    [Desktop Entry]
    Encoding=UTF-8
    Name=Calculator
    Comment=Perform simple calculations
    Exec=gnome-calculator
    Icon=gnome-calc3.png
    Terminal=false
    Type=Application
    X-GNOME-DocPath=gnome-calculator/gnome-calculator.xml
    Categories=GNOME;Application;Utility;

describes the most important keys in desktop entry files.

### Desktop Entry Keys

Desktop Entry Key | Description
--- | ---
`Encoding` | Specifies the encoding of the desktop entry file.
`Name` | Specifies the name of the item. This name is displayed on the item in the menu.
`Comment` | Specifies a short description of the item. The comment is displayed as a tooltip when you point to the item in the menu.
`Exec` | Specifies a command to execute when you choose the item from the menu.
`Icon` | Specifies the filename of an icon that represents the item. Does not specify the path to the filename, or the filename extension.
`Terminal` | Specifies whether the command in the `Exec` key runs in a terminal window. If the value is `true` the command runs in a terminal window. If the command does not create a window in which to run, the value of this key must be `true`.

`Type`

Specifies the type of item. This value is one of the following:

- `Application`: Enter this option for an item that starts an application.

- `Link`: Enter this option for an item that links to a file, folder, or FTP site.

`X-GNOME-DocPath` | Specifies the help file to display when you choose Help on application_name from the menu item popup menu.

`Categories`

Specifies the keywords that describe the item. The keywords are separated with semicolons (;). To see a list of the standard category keywords, see the following URL:

                    http://www.freedesktop.org/standards/VFolderDesktops.txt

The vfolder information files map the keywords to menus.

For more information on the keys in desktop entry files, see the following URL:

          http://www.freedesktop.org/standards/desktop-entry-spec/desktop-entry-spec.html

Panel launchers and desktop background objects also use desktop entry files. The desktop entry files for launchers and desktop background objects provide the same information as for items in a menu. For example, the desktop entry files provide the command to run when a user chooses the launcher or object.

## Directory Entry Files

A directory entry file is a data file that provides information about a menu. The directory entry file specifies the details for the menu such as a name, a tooltip, and an icon. Directory entry files have a `.directory` file extension.

The following is a sample directory entry file:

    [Desktop Entry]
    Name=Accessories
    Comment=Accessories menu
    Icon=gnome-util.png
    Type=Directory

describes the most important keys in directory entry files.

### Directory Entry Keys

Directory Entry Key | Description
--- | ---
`Name` | Specifies the name of the menu. This name is displayed on the menu.
`Comment` | Specifies a short description of the menu. The comment is displayed as a tooltip when you point to the menu.
`Icon` | Specifies the filename of an icon that represents the menu. Does not specify the path to the filename, or the filename extension.
`Type` | Specifies the type of menu. The value of this key is always `Directory`.

## Editing Menus

You use the following desktop components to edit menus:

- Nautilus file manager

- Menus on panels

When you use the file manager to add menus or menu items for all users, you must add the menu or menu item to a URI location. lists the menus to which you can add items, and the URI locations that correspond to the menus.

When you use panels to customize menus for all users, you use the menu item popup menu. For more information, see Working With Menus in the GNOME 2.2 Desktop User Guide.

You can also use menu configuration files and menu data files to customize menus.

### Adding Menus

You can add menus for all users in the following ways:

- Use the file manager.

- Modify the menu configuration files and menu data files.

#### To Add a Menu Using the File Manager

To add a menu for all users, perform the following steps:

1. In a file manager window, access the location where you want to add the menu. For example, to add a menu to the Applications menu, type `applications-all-users:///` in the Location field, then press Return.

2. Choose File New Folder. An untitled folder is added to the view pane. The name of the folder is selected.

3. Type a name for the folder, then press Return. The vfolder information file for the location that you accessed in step 1 is automatically updated with the details of the new menu. The name of the folder is displayed as the name of the menu.

You might need to reload the display of the file manager window before you can type the name for the folder.

The next time that users log in, the menu is in the assigned location.

#### To Add a Menu Using Menu Files

To add a menu for all users, perform the following steps:

1. Create a directory entry file for the item that you want to add. Create the directory entry file in the `/usr/gnome/share/gnome/vfolders` directory. For more information on directory entry files, see .

2. Locate the vfolder information file for the location where you want to add the menu. For example, to add a menu to the Applications menu, locate the file `/usr/gnome/etc/gnome-vfs-2.0/vfolders/applications-all-users.vfolder-info`.

3. In the vfolder information file, add a `<Folder>` element for the new menu. For more information on vfolder information files, see .

The next time that users log in, the menu is in the assigned location.

### To Add an Item to a Menu

To add an item to a menu for all users, perform the following steps:

1. Create a desktop entry file for the item that you want to add. For more information on desktop entry files, see .

2. Open a file manager window. Choose File New Window to open a second file manager window.

3. In one window, access the location where you want to add the menu item. For example, to add a menu item to the Preferences menu, type `preferences-all-users:///` in the Location field, then press Return.

4. In the other window, select the desktop entry file that you created for the menu item. Drag the desktop entry file to the location where you want to add the menu item.

   Alternatively, you can copy the desktop entry file, then paste the file into the location where you want to add the menu item.

The next time that users log in, the menu item is in the assigned location.

### To Edit the Properties of a Menu

To edit the properties of a menu for all users, perform the following steps:

1. From a panel, open the menu that you want to edit. Right-click on any item in the menu.

2. Choose Entire menu Properties. A Launcher Properties dialog is displayed.

3. Modify the properties of the menu in the Launcher Properties dialog. For more information on the elements in the Launcher Properties dialog, see Working With Panels in the GNOME 2.2 Desktop User Guide.

4. Click OK.

### To Edit a Menu Item

To edit a menu item, perform the following steps:

1. From a panel, open the menu that contains the item that you want to edit. Right-click on the item that you want to edit.

2. Choose Properties. A Launcher Properties dialog is displayed.

3. Modify the properties of the menu item in the Launcher Properties dialog. For more information on the elements in the Launcher Properties dialog, see Working With Panels in the GNOME 2.2 Desktop User Guide.

4. Click OK.

### To Delete an Item from a Menu

To delete an item from a menu, from a panel, open the menu that contains the item that you want to delete. Right-click on the item that you want to delete. Choose Remove this item.

The next time that users log in, the menu item is not displayed in the menu.

## To Configure Menus That Users Cannot Modify

Users cannot modify a menu if the following conditions are true:

- A vfolder information file that corresponds to the menu is present in the `/etc/gnome-vfs-2.0/vfolder` directory.

- The vfolder information file has the same name as the URI location that corresponds to the menu.

- The user permissions for the vfolder information file are set to read only.

To configure a menu so that users cannot modify the menu, perform the following steps:

1. Create a vfolder information file for the menu that you want to configure in the `/etc/gnome-vfs-2.0/vfolder` directory.

2. Give the vfolder information file the name of the URI location that corresponds to the menu that you want to configure. For example, to configure the Applications menu, create a vfolder information called `applications.vfolder-info` in the `/etc/gnome-vfs-2.0/vfolder` directory.

3. Set the permissions on the vfolder information file to read only.