X Power Tools

Chapter 12. Keyboard Configuration

Keyboards and XKB

Keyboard configuration is a more complicated issue than it might at first appear. There are many different keyboards sold, each with a different number or arrangement of keys. Each of these keyboard models may be sold in different markets, with different key caps installed, and users may want their keyboard to operate in specific ways.

Together, this means that there are thousands of possible keyboard configurations. The XKB extension tries to simplify this by combining a small number of keyboard selection parameters to compose a particular configuration. The final configuration is called a keyboard map.

In addition to keys that type characters or perform actions directly, a keyboard map almost always includes modifiers—such as Alt, Ctrl, and Shift—which change the operation of the other keys. It may also contain dead keys, which don’t actually type anything but cause the following character to be accented, so that pressing’ by itself doesn’t type an apostrophe (unless you type it twice), but pressing’ then A types á.

The keyboard map can also include a compose key, which is pressed before a twokey sequence to generate special characters (for example, pressing Compose-/-C yields the cent symbol [¢]; Compose-O-R yields the registered trademark symbol [®]; and Compose-comma-C yields a C with cedilla [ç]).

In these days of international communication, many users need to communicate in more than one language, so many keymaps have more ...