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.\" $Xorg: XChKMap.man,v 1.3 2000/08/17 19:41:56 cpqbld Exp $
.ds xL Programming with Xlib
.TH XGetDeviceKeyMapping __LIB_MAN_SUFFIX__ __xorgversion__ "X FUNCTIONS"
.SH NAME
XGetDeviceKeyMapping, XChangeDeviceKeyMapping \- query or change device key mappings
.SH SYNTAX
\fB
int XChangeDeviceKeyMapping(\^Display *\fIdisplay\fP\^, XDevice
*\fIdevice\fP\^, int \fIfirst_keycode\fP\^, int \fIkeysyms_per_keycode\fP\^,
KeySym *\fIkeysyms\fP\^, int \fIkeycode_count\fP\^); 
.HP
KeySym *XGetDeviceKeyMapping(\^Display *\fIdisplay\fP\^, XDevice
*\fIdevice\fP\^, KeyCode \fIfirst_keycode\fP\^, int \fIkeycode_count\fP\^, int
*\fIkeysyms_per_keycode_return\fP\^); 
.fi
\fP
.SH ARGUMENTS
.TP 12
.I display
Specifies the connection to the X server.
.TP 12
.I device
Specifies the device whose key mapping is to be queried or modified.
.TP 12
.I first_keycode
Specifies the first KeyCode to be returned.
.TP 12
.I keycode_count
Specifies the number of KeyCodes to be returned or modified.
.TP 12
.I keysyms_per_keycode
Specifies the number of KeySyms per KeyCode.
.TP 12
.I keysyms_per_keycode_return
Specifies the address of a variable into which the number of KeySyms per KeyCode
will be returned.
.TP 12
.I keysyms
Specifies the address of an array of KeySyms.
.SH DESCRIPTION
For the specified device,
the \fIXGetDeviceKeyMapping\fP request returns
the symbols for the specified number of KeyCodes
starting with first_keycode.
The value specified in first_keycode must be greater than 
or equal to min_keycode as returned by
\fIXListInputDevices\fP, 
or a
\fIBadValue\fP
error results.
In addition, the following expression must be less than or equal 
to max_keycode as returned by
\fIXListInputDevices\fP:
.LP
.DS 
first_keycode + keycode_count \- 1
.DE
.LP
If this is not the case, a 
\fIBadValue\fP
error results. 
The number of elements in the KeySyms list is:
.LP
.DS 
keycode_count * keysyms_per_keycode_return
.DE
.LP
KeySym number N, counting from zero, for KeyCode K has the following index
in the list, counting from zero: 
.DS
(K \- first_code) * keysyms_per_code_return + N
.DE
.LP
The X server arbitrarily chooses the keysyms_per_keycode_return value 
to be large enough to report all requested symbols. 
A special KeySym value of 
\fINoSymbol\fP
is used to fill in unused elements for
individual KeyCodes.
To free the storage returned by 
\fIXGetDeviceKeyMapping\fP,
use
\fIXFree\fP.
.LP
If the specified device does not support input class keys, a \fIBadMatch\fP
error will result.
.LP
\fIXGetDeviceKeyMapping\fP
can generate a \fIBadDevice\fP, \fIBadMatch\fP, or \fIBadValue\fP
error.
.LP
For the specified device, the \fIXChangeDeviceKeyMapping\fP
request defines the symbols for the specified number of KeyCodes
starting with first_keycode.
The symbols for KeyCodes outside this range remain unchanged.  
The number of elements in keysyms must be:
.LP
.DS
num_codes * keysyms_per_keycode
.DE
.LP
The specified first_keycode must be greater than or equal to min_keycode 
returned by \fIXListInputDevices\fP, or a \fIBadValue\fP error results.
In addition, the following expression must be less than or equal to 
max_keycode as returned by
\fIXListInputDevices\fP, or a \fIBadValue\fP error results:
.LP
.DS
first_keycode + num_codes \- 1
.DE
.LP
KeySym number N, counting from zero, for KeyCode K has the following index
in keysyms, counting from zero: 
.LP
.DS 
(K \- first_keycode) * keysyms_per_keycode + N
.DE
.LP
The specified keysyms_per_keycode can be chosen arbitrarily by the client
to be large enough to hold all desired symbols. 
A special KeySym value of 
\fINoSymbol\fP
should be used to fill in unused elements 
for individual KeyCodes.  
It is legal for 
\fINoSymbol\fP 
to appear in nontrailing positions
of the effective list for a KeyCode.
\fIXChangeDeviceKeyMapping\fP generates a \fIDeviceMappingNotify\fP
event that is sent to all clients that have selected that type of event.
.LP
There is no requirement that the X server interpret this mapping. 
It is merely stored for reading and writing by clients.
.LP
If the specified device does not support input class keys, a \fIBadMatch\fP
error results.
.LP
\fIXChangeDeviceKeyMapping\fP can generate a \fIBadDevice\fP,
\fIBadMatch\fP, \fIBadAlloc\fP, or \fIBadValue\fP  error.
.LP
.SH DIAGNOSTICS
.TP 12
\fIBadDevice\fP
An invalid device was specified.  The specified device does not exist or has 
not been opened by this client via \fIXOpenInputDevice\fP.  This error may
also occur if the specified device is the X keyboard or X pointer device.
.TP 12
\fIBadMatch\fP
This error may occur if an \fIXGetDeviceKeyMapping\fP or 
\fIXChangeDeviceKeyMapping\fP request was made 
specifying
a device that has no keys.
.TP 12
\fIBadValue\fP
Some numeric value falls outside the range of values accepted by the request.
Unless a specific range is specified for an argument, the full range defined
by the argument's type is accepted.  Any argument defined as a set of
alternatives can generate this error.
.TP 12
\fIBadAlloc\fP
The server failed to allocate the requested resource or server memory.
.SH "SEE ALSO"
XSetDeviceButtonMapping(3) 
.br
XSetDeviceModifierMapping(3) 
.br
\fI\*(xL\fP