XGetDeviceKeyMapping(3X11) X FUNCTIONS XGetDeviceKeyMapping(3X11)
NAME
XGetDeviceKeyMapping, XChangeDeviceKeyMapping - query or
change device key mappings
SYNTAX
int XChangeDeviceKeyMapping(Display *display, XDevice *dev-
ice, int first_keycode, int keysyms_per_keycode, KeySym
*keysyms, int keycode_count);
KeySym *XGetDeviceKeyMapping(Display *display, XDevice *dev-
ice, 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 modified.
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_keycode. 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 XListInputDev-
ices:
first_keycode + keycode_count - 1
If this is not the case, a BadValue error results. The
number of elements in the KeySyms list is:
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XGetDeviceKeyMapping(3X11) X FUNCTIONS XGetDeviceKeyMapping(3X11)
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 XGetDeviceKeyMap-
ping, 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 Key-
Codes 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_keycode 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 XListInput-
Devices, 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 sym-
bols. 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 gen-
erates 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
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XGetDeviceKeyMapping(3X11) X FUNCTIONS XGetDeviceKeyMapping(3X11)
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 XOpenInputDevice. 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 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.
BadAlloc The server failed to allocate the requested
resource or server memory.
SEE ALSO
XSetDeviceButtonMapping(3X11)
XSetDeviceModifierMapping(3X11)
Programming with Xlib
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