XkbGetDeviceLedInfo - Man Page
Query the indicator names, maps, and state associated with an LED feedback of an input extension device
Status XkbGetDeviceLedInfo (Display *dpy, XkbDeviceInfoPtr device_info, unsigned int led_class, unsigned int led_id, unsigned int which);
connection to X server
structure to update with results
LED feedback class assigned by input extension
LED feedback ID assigned by input extension
mask indicating desired information
XkbGetDeviceLedInfo queries the server for the desired LED information for the feedback specified by led_class and led_id for the X input extension device indicated by device_spec->device_info and waits for a reply. If successful, XkbGetDeviceLedInfo backfills the relevant fields of device_info as determined by which with the results and returns Success. Valid values for which are the inclusive OR of any of XkbXI_IndicatorNamesMask, XkbXI_IndicatorMapsMask, and XkbXI_IndicatorStateMask.
The fields of device_info that are filled in when this request succeeds are name, type, supported, and unsupported, and portions of the leds structure corresponding to led_class and led_id as indicated by the bits set in which. The device_info->leds vector is allocated if necessary and sz_leds and num_leds filled in. The led_class, led_id and phys_indicators fields of the device_info->leds entry corresponding to led_class and led_id are always filled in.
If which contains XkbXI_IndicatorNamesMask, the names_present and names fields of the device_info->leds structure corresponding to led_class and led_id are updated, if which contains XkbXI_IndicatorStateMask, the corresponding state field is updated, and if which contains XkbXI_IndicatorMapsMask, the maps_present and maps fields are updated.
If a compatible version of Xkb is not available in the server or the Xkb extension has not been properly initialized, XkbGetDeviceLedInfo returns BadAccess. If allocation errors occur, a BadAlloc status is returned. If the device has no indicators, a BadMatch error is returned. If ledClass or ledID have illegal values, a BadValue error is returned. If they have legal values but do not specify a feedback that contains LEDs and is associated with the specified device, a BadMatch error is returned.
The Xkb extension has not been properly initialized
Unable to allocate storage
A compatible version of Xkb was not available in the server or an argument has correct type and range, but is otherwise invalid
An argument is out of range