# libxkbcommon xkbcommon is a keymap compiler and support library which processes a reduced subset of keymaps as defined by the XKB specification. Primarily, a keymap is created from a set of Rules/Model/Layout/Variant/Options names, processed through an XKB ruleset, and compiled into a struct xkb_keymap, which is the base type for all xkbcommon operations. From an xkb_keymap, an xkb_state object is created which holds the current state of all modifiers, groups, LEDs, etc, relating to that keymap. All key events must be fed into the xkb_state object using xkb_state_update_key(). Once this is done, the xkb_state object will be properly updated, and the keysyms to use can be obtained with xkb_state_key_get_syms(). ## Quick Guide See [Quick Guide](doc/quick-guide.md). ## API While libxkbcommon's API is somewhat derived from the classic XKB API as found in X11/extensions/XKB.h and friends, it has been substantially reworked to expose fewer internal details to clients. See the [API Documentation](http://xkbcommon.org/doc/current/modules.html). ## Dataset libxkbcommon does not distribute a keymap dataset itself, other than for testing purposes. The most common dataset is xkeyboard-config, which is used by all current distributions for their X11 XKB data. More information on xkeyboard-config is available here: http://www.freedesktop.org/wiki/Software/XKeyboardConfig ## Relation to X11 Relative to the XKB 1.1 specification implemented in current X servers, xkbcommon has removed support for some parts of the specification which introduced unnecessary complications. Many of these removals were in fact not implemented, or half-implemented at best, as well as being totally unused in the standard dataset. Notable removals: - geometry support + there were very few geometry definitions available, and while xkbcommon was responsible for parsing this insanely complex format, it never actually did anything with it + hopefully someone will develop a companion library which supports keyboard geometries in a more useful format - KcCGST (keycodes/compat/geometry/symbols/types) API + use RMLVO instead; KcCGST is now an implementation detail + including pre-defined keymap files - XKM support + may come in an optional X11 support/compatibility library - around half of the interpret actions + pointer device, message and redirect actions in particular - non-virtual modifiers + core and virtual modifiers have been collapsed into the same namespace, with a 'significant' flag that largely parallels the core/virtual split - radio groups + completely unused in current keymaps, never fully implemented - overlays + almost completely unused in current keymaps - key behaviors + used to implement radio groups and overlays, and to deal with things like keys that physically lock; unused in current keymaps - indicator behaviours such as LED-controls-key + the only supported LED behaviour is key-controls-LED; again this was never really used in current keymaps Notable additions: - 32-bit keycodes - extended number of modifiers - extended number of groups - multiple keysyms per level + this requires incompatible dataset changes, such that X11 would not be able to parse these ## Development An extremely rudimentary homepage can be found at http://xkbcommon.org xkbcommon is maintained in git at https://github.com/xkbcommon/libxkbcommon Patches are always welcome, and may be sent to either or Bugs are also welcome, and may be reported either at Bugzilla https://bugs.freedesktop.org/describecomponents.cgi?product=libxkbcommon or Github https://github.com/xkbcommon/libxkbcommon/issues The maintainers are - Daniel Stone - Ran Benita ## Credits Many thanks are due to Dan Nicholson for his heroic work in getting xkbcommon off the ground initially.