Preparsed Data

Preparsed data is report descriptor data associated with a top-level collection. User-mode applications or kernel-mode drivers use preparsed data to extract information about specific HID controls without having to obtain and interpret a device's entire report descriptor. A user-mode application obtains a collection's preparsed data by using HidD_GetPreparsedData and a kernel-mode driver uses an IOCTL_HID_GET_COLLECTION_DESCRIPTOR request.

The following HIDClass support routines support extracting and setting button and value data:

• HidP_GetButtons
• HidP_SetButtons
• HidP_UnsetButtons
• HidP_GetUsageValue
• HidP_SetUsageValue
• HidP_GetScaledUsageValue
• HidP_SetScaledUsageValue
• HidP_GetUsageValueArray
• HidP_SetUsageValueArray