diff options
Diffstat (limited to 'src/3rdparty/xkbcommon/README.md')
| -rw-r--r-- | src/3rdparty/xkbcommon/README.md | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/src/3rdparty/xkbcommon/README.md b/src/3rdparty/xkbcommon/README.md new file mode 100644 index 0000000000..2627a324a6 --- /dev/null +++ b/src/3rdparty/xkbcommon/README.md @@ -0,0 +1,109 @@ +# 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(). + +libxkbcommon does not distribute a dataset itself, other than for testing +purposes. The most common dataset is xkeyboard-config, as 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 + +## Quick Guide + +See [Quick Guide](doc/quick-guide.md). + +## API + +While xkbcommon'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. The supported API is available +in the xkbcommon/xkbcommon-*.h files. Additional support is provided for +X11 (XCB) clients, in the xkbcommon-x11 library, xkbcommon/xkbcommon-x11.h. + +The xkbcommon API and ABI are stable. We will attempt to not break ABI during +a minor release series, so applications written against 0.1.0 should be +completely compatible with 0.5.3, but not necessarily with 1.0.0. However, new +symbols may be introduced in any release. Thus, anyone packaging xkbcommon +should make sure any package depending on it depends on a release greater than +or equal to the version it was built against (or earlier, if it doesn't use +any newly-introduced symbols), but less than the next major release. + +## 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 + <xorg-devel@lists.x.org> or <wayland-devel@lists.freedesktop.org> + +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 <daniel@fooishbar.org> +- Ran Benita <ran234@gmail.com> + +## Credits + +Many thanks are due to Dan Nicholson for his heroic work in getting xkbcommon +off the ground initially. |