Hash :
2a2a8d7d
Author :
Date :
2013-08-13T18:57:43
state: apply capitalization transformation on keysyms
The xkbproto spec says:
http://www.x.org/releases/current/doc/kbproto/xkbproto.html#Interpreting_the_Lock_Modifier
If the Lock modifier is not consumed by the symbol lookup process,
routines that determine the symbol and string that correspond to
an event should capitalize the result.
This was not an issue until now, because most xkeyboard-config keymaps
do not utilize this "feature", and specify the keysyms for the Lock
modifier explicitly instead. However, some keymaps do depend on it, e.g.
ch(fr) for eacute and others.
The spec goes on to describe two options for doing this transformation:
locale-sensitive and locale-insensitive. We opt for the latter; it is
less desirable but we don't want *that* headache.
Also, only xkb_state_key_get_one_sym() is changed;
xkb_state_key_get_syms() is left as-is, and always reports the
untransformed keysyms. This is for the following reasons:
- The API doesn't allow it, since we return a const pointer directly to
the keymap keysyms table and we can't transform that.
- The transformation doesn't make sense for multiple-keysyms.
- It can be useful for an application to get the "raw" keysyms if it
wants to (e.g. maybe it wants to do the transformation itself).
Finally, note that xkb_state_mod_index_is_consumed() does *not*
report Lock as consumed even if it was used in the transformation. This
is what Xlib does.
This definitely doesn't fall under the "hard to misuse" API rule but
it's the best we can do.
https://bugs.freedesktop.org/show_bug.cgi?id=67167
Reported-By: Gatis Paeglis <gatis.paeglis@digia.com>
Signed-off-by: Ran Benita <ran234@gmail.com>
Overview {#mainpage}
========
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
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 only supported API is available
in <xkbcommon/xkbcommon.h>. Any definition not in this header (including
accessing internal structures through the old macros previously available)
should be regarded as an implementation detail and is liable to change at any
time.
During its early development, xkbcommon does not promise API or ABI stability.
Regardless, we will attempt to not break ABI during a minor release series,
so applications written against 0.1.0 should be completely compatible with
0.1.3, but not necessarily with 0.2.0. 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.
xkbcommon 1.x will offer full API and ABI stability for its lifetime, with a
soname of libxkbcommon.so.1. Any ABI breaks will wait until xkbcommon 2.0,
which will be libxkbcommon.so.2.
The xkbcomp command-line tool has also been removed, although this will
likely reappear in a later 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 freedesktop.org:
git://anongit.freedesktop.org/git/libxkbcommon
Patches are always welcome, and may be sent to either xorg-devel@lists.x.org,
or wayland-devel@lists.freedesktop.org. Bugs are tracked in Bugzilla at:
http://bugs.freedesktop.org
The maintainer is Daniel Stone, who can be reached at:
<daniel@fooishbar.org>
Credits
=======
Many thanks are due to Dan Nicholson for his heroic work in getting xkbcommon
off the ground initially, as well as to Ran Benita for subsequent development.