hidd_get_usage_value()

Get value from report for usage page and usage

Synopsis:

#include <sys/hiddi.h>

int hidd_get_usage_value( struct hidd_report_instance *report_instance,
                          struct hidd_collection *collection,
                          _Uint16t usage_page,
                          _Uint16t usage,
                          void *report_data,
                          _Uint32t *usage_value );

Arguments:

report_instance

The handle of a report (from hidd_report_attach()).

collection
The handle of the collection, as returned by hidd_get_collections() or by hidd_report_collection(). If collection is NULL, all collections are searched. Otherwise, only the collection specified is searched.
usage_page

The usage page of the report (refer to the HID spec and HID usage tables).

usage
The usage of the report (refer to the HID spec and HID usage tables).
report_data
The raw report data as returned in the report callback.
usage_value
A pointer to a memory where to store report’s usage value.

Description:

The hidd_get_usage_value() function gets the value from the report for a usage_page and usage. You would typically use this function in the report callback to get values such as x/y movements of a mouse.

Returns:

EOK
Success.
EINVAL
The report_instance, report_data, or usage_value is NULL.
ENOENT
There's no entry in the report for usage_page or usage.

Classification:

QNX OS

Safety:
Cancellation point Yes
Signal handler No
Thread Yes
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