5b5b67f28c
Unlike current xkbcommon, X11’s xkbcomp allows to remove entries in
the modifiers’ map using “modifier_map None { … }”.
“None” is translated to the special value “XkbNoModifier” defined in
“X11/extensions/XKB.h”. Then it relies on the fact that in "CopyModMapDef",
the following code:
1U << entry->modifier
ends up being zero when “entry->modifier” is “XkbNoModifier” (i.e. 0xFF).
Indeed, it relies on the overflow behaviour of the left shift, which in
practice resolves to use only the 5 low bits of the shift amount, i.e.
0x1F here. Then the result of “1U << 0xFF” is cast to “char”, i.e. 0.
This is a good trick but too magical, so in libxkbcommon we will use
an explicit test against our new constant XKB_MOD_NONE.
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|---|---|---|
| .github/workflows | ||
| bench | ||
| doc | ||
| fuzz | ||
| include/xkbcommon | ||
| scripts | ||
| src | ||
| test | ||
| tools | ||
| .editorconfig | ||
| .uncrustify.cfg | ||
| LICENSE | ||
| NEWS | ||
| PACKAGING | ||
| README.md | ||
| meson.build | ||
| meson_options.txt | ||
| xkbcommon-x11.map | ||
| xkbcommon.map | ||
| xkbregistry.map | ||
README.md
libxkbcommon
libxkbcommon is a keyboard keymap compiler and support library which processes a reduced subset of keymaps as defined by the XKB (X Keyboard Extension) specification. It also contains a module for handling Compose and dead keys and a separate library for listing available keyboard layouts.
Quick Guide
See Quick Guide.
Building
libxkbcommon is built with Meson:
meson setup build
ninja -C build
ninja -C build test # Run the tests.
To build for use with Wayland, you can disable X11 support while still using the X11 keyboard configuration resource files thusly:
meson setup build \
-Denable-x11=false \
-Dxkb-config-root=/usr/share/X11/xkb \
-Dx-locale-root=/usr/share/X11/locale
ninja -C build
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.
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: https://www.freedesktop.org/wiki/Software/XKeyboardConfig
The dataset for Compose is distributed in libX11, as part of the X locale data.
Relation to X11
See Compatibility notes.
Development
An extremely rudimentary homepage can be found at https://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 or in a GitHub pull request.
Bug reports (and usage questions) are also welcome, and may be filed at GitHub.
The maintainers are
- Daniel Stone daniel@fooishbar.org
- Ran Benita ran@unusedvar.com
Credits
Many thanks are due to Dan Nicholson for his heroic work in getting xkbcommon off the ground initially.