134 lines
4.5 KiB
Groff
134 lines
4.5 KiB
Groff
.\" Copyright 1999 Oracle and/or its affiliates. All rights reserved.
|
|
.\"
|
|
.\" Permission is hereby granted, free of charge, to any person obtaining a
|
|
.\" copy of this software and associated documentation files (the "Software"),
|
|
.\" to deal in the Software without restriction, including without limitation
|
|
.\" the rights to use, copy, modify, merge, publish, distribute, sublicense,
|
|
.\" and/or sell copies of the Software, and to permit persons to whom the
|
|
.\" Software is furnished to do so, subject to the following conditions:
|
|
.\"
|
|
.\" The above copyright notice and this permission notice (including the next
|
|
.\" paragraph) shall be included in all copies or substantial portions of the
|
|
.\" Software.
|
|
.\"
|
|
.\" THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
.\" IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
.\" FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
|
|
.\" THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
.\" LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
|
|
.\" FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
|
|
.\" DEALINGS IN THE SOFTWARE.
|
|
.\"
|
|
.TH XkbKeyAction __libmansuffix__ __xorgversion__ "XKB FUNCTIONS"
|
|
.SH NAME
|
|
XkbKeyAction \- Returns the key action
|
|
.SH SYNOPSIS
|
|
.HP
|
|
.B XkbAction XkbKeyAction
|
|
.BI "(\^XkbDescPtr " "xkb" "\^,"
|
|
.BI "KeyCode " "keycode" "\^,"
|
|
.BI "int " "idx" "\^);"
|
|
.if n .ti +5n
|
|
.if t .ti +.5i
|
|
.SH ARGUMENTS
|
|
.TP
|
|
.I \- xkb
|
|
Xkb description of interest
|
|
.TP
|
|
.I \- keycode
|
|
keycode of interest
|
|
.TP
|
|
.I \- idx
|
|
index for group and shift level
|
|
.SH DESCRIPTION
|
|
.LP
|
|
A key action defines the effect key presses and releases have on the internal
|
|
state of the server. For
|
|
example, the expected key action associated with pressing the Shift key is to
|
|
set the Shift modifier.
|
|
There is zero or one key action associated with each keysym bound to each key.
|
|
|
|
Just as the entire list of key symbols for the keyboard mapping is held in the
|
|
.I syms
|
|
field of the client map, the entire list of key actions for the keyboard mapping
|
|
is held in the
|
|
.I acts
|
|
array of the server map. The total size of
|
|
.I acts
|
|
is specified by
|
|
.I size_acts,
|
|
and the number of entries is specified by
|
|
.I num_acts.
|
|
|
|
The
|
|
.I key_acts
|
|
array, indexed by keycode, describes the actions associated with a key. The
|
|
.I key_acts
|
|
array has
|
|
.I min_key_code
|
|
unused entries at the start to allow direct indexing using a keycode. If a
|
|
.I key_acts
|
|
entry is zero, it means the key does not have any actions associated with it. If
|
|
an entry is not zero,
|
|
the entry represents an index into the
|
|
.I acts
|
|
field of the server map, much as the
|
|
.I offset
|
|
field of a KeySymMapRec structure is an index into the
|
|
.I syms
|
|
field of the client map.
|
|
|
|
The reason the
|
|
.I acts
|
|
field is a linear list of XkbActions is to reduce the memory consumption
|
|
associated with a keymap.
|
|
Because Xkb allows individual keys to have multiple shift levels and a different
|
|
number of groups per
|
|
key, a single two-dimensional array of KeySyms would potentially be very large
|
|
and sparse. Instead, Xkb
|
|
provides a small two-dimensional array of XkbActions for each key. To store all
|
|
of these individual
|
|
arrays, Xkb concatenates each array together in the
|
|
.I acts
|
|
field of the server map.
|
|
|
|
The key action structures consist only of fields of type char or unsigned char.
|
|
This is done to
|
|
optimize data transfer when the server sends bytes over the wire. If the fields
|
|
are anything but bytes,
|
|
the server has to sift through all of the actions and swap any nonbyte fields.
|
|
Because they consist of
|
|
nothing but bytes, it can just copy them out.
|
|
|
|
.I XkbKeyAction
|
|
returns the key action indexed by
|
|
.I idx
|
|
in the two-dimensional array of key actions associated with the key
|
|
corresponding to
|
|
.I keycode.idx
|
|
may be computed from the group and shift level of interest as follows:
|
|
.nf
|
|
|
|
idx = group_index * key_width + shift_level
|
|
.fi
|
|
.SH STRUCTURES
|
|
.LP
|
|
The KeySymMapRec structure is defined as follows:
|
|
.nf
|
|
|
|
#define XkbNumKbdGroups 4
|
|
#define XkbMaxKbdGroup (XkbNumKbdGroups-1)
|
|
|
|
typedef struct { /\(** map to keysyms for a single keycode
|
|
*/
|
|
unsigned char kt_index[XkbNumKbdGroups]; /\(** key type index for
|
|
each group */
|
|
unsigned char group_info; /\(** # of groups and out of range group
|
|
handling */
|
|
unsigned char width; /\(** max # of shift levels for key */
|
|
unsigned short offset; /\(** index to keysym table in syms array
|
|
*/
|
|
} XkbSymMapRec, *XkbSymMapPtr;
|
|
|
|
.fi
|