To change characteristics of an X Input Extension device in the server, first modify a local copy of the device structure and then use either XkbSetDeviceInfo, or, to save network traffic, use an XkbDeviceChangesRec structure and call XkbChangeDeviceInfo to download the changes to the server.
XkbSetDeviceInfo sends a request to the server to modify the characteristics of the device specified in the device_info structure. The particular characteristics modified are identified by the bits set in which and take their values from the relevant fields in device_info (see Table 1). XkbSetDeviceInfo returns True if the request was successfully sent to the server. If the X server implementation does not allow interaction between the X input extension and the Xkb Extension, the function does nothing and returns False.
Table 1 XkbDeviceInfoRec Mask Bits
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Name XkbDeviceInfoRec Value Capability If Set
Fields Effected
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XkbXI_KeyboardsMask (1L <<0) Clients can use all
Xkb requests and events
with KeyClass devices
supported by the input
device extension.
XkbXI_ButtonActionsMask num_btns (1L <<1) Clients can assign key
btn_acts actions to buttons
non-KeyClass input
extension devices.
XkbXI_IndicatorNamesMask leds->names (1L <<2) Clients can assign
names to indicators on
non-KeyClass input
extension devices.
XkbXI_IndicatorMapsMask leds->maps (1L <<3) Clients can assign
indicator maps to
indicators on
non-KeyClass input
extension devices.
XkbXI_IndicatorStateMask leds->state (1L <<4) Clients can request
the status of indicators
on non-KeyClass input
extension devices.
XkbXI_IndicatorsMask sz_leds (0x1c) XkbXI_IndicatorNamesMask |
num_leds XkbXI_IndicatorMapsMask |
leds->* XkbXI_IndicatorStateMask
XkbXI_UnsupportedFeaturesMask unsupported (1L <<15)
XkbXI_AllDeviceFeaturesMask Those selected (0x1e) XkbXI_IndicatorsMask |
by Value Column XkbSI_ButtonActionsMask
masks
XkbXI_AllFeaturesMask Those selected (0x1f) XkbSI_AllDeviceFeaturesMask |
by Value Column XkbSI_KeyboardsMask
masks
XkbXI_AllDetailsMask Those selected (0x801f) XkbXI_AllFeaturesMask |
by Value column XkbXI_UnsupportedFeaturesMask
masks
The
which
parameter specifies which aspects of the device should be changed and is a
bitmask composed of an inclusive OR or one or more of the following bits:
XkbXI_ButtonActionsMask, XkbXI_IndicatorNamesMask, XkbXI_IndicatorMapsMask. If
the features requested to be manipulated in
which
are valid for the device, but the server does not support assignment of one or
more of them, that particular portion of the request is ignored.
If the device specified in
device_info->device_spec
does not contain buttons and a request affecting buttons is made, or the device
does not contain indicators and a request affecting indicators is made, a
BadMatch protocol error results.
If the XkbXI_ButtonActionsMask bit is set in the supported mask returned by XkbGetDeviceInfo, the Xkb extension allows applications to assign key actions to buttons on input extension devices other than the core keyboard device. If the XkbXI_ButtonActionsMask is set in which, the actions for all buttons specified in device_info are set to the XkbActions specified in device_info->btn_acts. If the number of buttons requested to be updated is not valid for the device, XkbSetDeviceInfo returns False and a BadValue protocol error results.
If the XkbXI_IndicatorMaps and / or XkbXI_IndicatorNamesMask bit is set in the
supported
mask returned by
XkbGetDeviceInfo,
the Xkb extension allows applications to assign maps and / or names to the
indicators of nonkeyboard extension devices. If supported, maps and / or names
can be assigned to all extension device indicators, whether they are part of a
keyboard feedback or part of an indicator feedback.
If the XkbXI_IndicatorMapsMask and / or XkbXI_IndicatorNamesMask flag is set in
which,
the indicator maps and / or names for all
device_info->num_leds
indicator devices specified in
device_info->leds
are set to the maps and / or names specified in
device_info->leds. device_info->leds->led_class
and
led_id
specify the input extension class and device ID for each indicator device to
modify; if they have invalid values, a BadValue protocol error results and
XkbSetDeviceInfo
returns False. If they have legal values but do not specify a keyboard or
indicator class feedback for the device in question, a BadMatch error results.
If any of the values in
device_info->leds->names
are not a valid Atom or None, a BadAtom protocol error results.
Changes to an Xkb extension device may be tracked by listening to XkbDeviceExtensionNotify events and accumulating the changes in an XkbDeviceChangesRec structure. The changes noted in the structure may then be used in subsequent operations to update either a server configuration or a local copy of an Xkb extension device configuration. The changes structure is defined as follows:
typedef struct _XkbDeviceChanges {
unsigned int changed; /* bits indicating what has changed */
unsigned short first_btn; /* number of first button which changed, if any */
unsigned short num_btns; /* number of buttons that have changed */
XkbDeviceLedChangesRec leds;
} XkbDeviceChangesRec,*XkbDeviceChangesPtr;