XGetDeviceKeyMapping(3X11) X FUNCTIONS XGetDeviceKeyMapping(3X11)NAME
XGetDeviceKeyMapping, XChangeDeviceKeyMapping - query or change device
key mappings
SYNTAX
XChangeDeviceKeyMapping(display, device, first_keycode,
keysyms_per_keycode, keysyms, keycode_count)
Display *display;
XDevice *device;
int first_keycode;
int keysyms_per_keycode;
KeySym *keysyms;
int keycode_count;
KeySym *XGetDeviceKeyMapping(display, device, first_keycode, keycode_count,
keysyms_per_keycode_return)
Display *display;
XDevice *device;
KeyCode first_keycode;
int keycode_count;
int *keysyms_per_keycode_return;
ARGUMENTS
display Specifies the connection to the X server.
device Specifies the device whose key mapping is to be queried or
modified.
first_keycode
Specifies the first KeyCode to be returned.
keycode_count
Specifies the number of KeyCodes to be returned or modi‐
fied.
keysyms_per_keycode
Specifies the number of KeySyms per KeyCode.
keysyms_per_keycode_return
Specifies the address of a variable into which the number
of KeySyms per KeyCode will be returned.
keysyms Specifies the address of an array of KeySyms.
DESCRIPTION
For the specified device, the XGetDeviceKeyMapping request returns the
symbols for the specified number of KeyCodes starting with first_key‐
code. The value specified in first_keycode must be greater than or
equal to min_keycode as returned by XListInputDevices, or a BadValue
error results. In addition, the following expression must be less than
or equal to max_keycode as returned by XListInputDevices:
first_keycode + keycode_count - 1
If this is not the case, a BadValue error results. The number of ele‐
ments in the KeySyms list is:
keycode_count * keysyms_per_keycode_return
KeySym number N, counting from zero, for KeyCode K has the following
index in the list, counting from zero: (K - first_code) *
keysyms_per_code_return + N
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 NoSymbol is used to fill in unused elements for individual
KeyCodes. To free the storage returned by XGetDeviceKeyMapping, use
XFree.
If the specified device does not support input class keys, a BadMatch
error will result.
XGetDeviceKeyMapping can generate a BadDevice, BadMatch, or BadValue
error.
For the specified device, the XChangeDeviceKeyMapping 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:
num_codes * keysyms_per_keycode
The specified first_keycode must be greater than or equal to min_key‐
code returned by XListInputDevices, or a BadValue error results. In
addition, the following expression must be less than or equal to
max_keycode as returned by XListInputDevices, or a BadValue error
results:
first_keycode + num_codes - 1
KeySym number N, counting from zero, for KeyCode K has the following
index in keysyms, counting from zero:
(K - first_keycode) * keysyms_per_keycode + N
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 NoSymbol should be used to fill in unused elements for
individual KeyCodes. It is legal for NoSymbol to appear in nontrailing
positions of the effective list for a KeyCode. XChangeDeviceKeyMapping
generates a DeviceMappingNotify event that is sent to all clients that
have selected that type of event.
There is no requirement that the X server interpret this mapping. It
is merely stored for reading and writing by clients.
If the specified device does not support input class keys, a BadMatch
error results.
XChangeDeviceKeyMapping can generate a BadDevice, BadMatch, BadAlloc,
or BadValue error.
DIAGNOSTICS
BadDevice An invalid device was specified. The specified device does
not exist or has not been opened by this client via XOpen‐
InputDevice. This error may also occur if the specified
device is the X keyboard or X pointer device.
BadMatch This error may occur if an XGetDeviceKeyMapping or
XChangeDeviceKeyMapping request was made specifying a
device that has no keys.
BadValue Some numeric value falls outside the range of values
accepted by the request. Unless a specific range is speci‐
fied for an argument, the full range defined by the argu‐
ment's type is accepted. Any argument defined as a set of
alternatives can generate this error.
BadAlloc The server failed to allocate the requested resource or
server memory.
SEE ALSOXSetDeviceButtonMapping(3X11)XSetDeviceModifierMapping(3X11)
Programming with Xlib
X Version 11 Release 6 XGetDeviceKeyMapping(3X11)
