xref: /xsrc/external/mit/libXi/dist/man/XGetDeviceKeyMapping.txt

XGETDEVICEKEYMAPPING(libmansuffix)
==================================

NAME
----

   XGetDeviceKeyMapping, XChangeDeviceKeyMapping - query or change
   device key mappings

SYNOPSIS
--------

   #include <X11/extensions/XInput.h>

   KeySym *XGetDeviceKeyMapping( Display *display,
                                 XDevice *device,
                                 KeyCode first_keycode,
                                 int keycode_count,
                                 int *keysyms_per_keycode_return);
   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 XListInputDevices:

   first_keycode + keycode_count - 1

   If this is not the case, a BadValue error results. The number
   of elements 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_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 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
          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(libmansuffix), XSetDeviceModifierMapping(libmansuffix)