Crate hid_report

Parse USB HID report descriptors and pretty print them.

Example

use hid_report::{parse, pretty_print};

let bytes = [
    0x05, 0x0C, 0x09, 0x01, 0xA1, 0x01, 0x85, 0x02, 0x19,
    0x00, 0x2A, 0x3C, 0x02, 0x15, 0x00, 0x26, 0x3C, 0x02,
    0x95, 0x01, 0x75, 0x10, 0x81, 0x00, 0xC0,
];
let mut items = parse(bytes);
assert_eq!(items.next().unwrap().to_string(), "Usage Page (Consumer)");
assert_eq!(items.next().unwrap().to_string(), "Usage (Consumer Control)");
assert_eq!(items.next().unwrap().to_string(), "Collection (Application)");
assert_eq!(items.next().unwrap().to_string(), "Report ID (2)");
assert_eq!(items.next().unwrap().to_string(), "Usage Minimum (Undefined)");
assert_eq!(items.next().unwrap().to_string(), "Usage Maximum (AC Format)");
assert_eq!(items.next().unwrap().to_string(), "Logical Minimum (0)");
assert_eq!(items.next().unwrap().to_string(), "Logical Maximum (572)");
assert_eq!(items.next().unwrap().to_string(), "Report Count (1)");
assert_eq!(items.next().unwrap().to_string(), "Report Size (16)");
assert_eq!(
    items.next().unwrap().to_string(),
    "Input (Data, Array, Absolute, No Wrap, Linear, Preferred State, No Null Position)"
);
assert_eq!(items.next().unwrap().to_string(), "End Collection");
assert_eq!(items.next(), None);

let items = parse(bytes).collect::<Vec<_>>();

const EXPECTED: &str = indoc::indoc! {"
    0x05, 0x0C        // Usage Page (Consumer)
    0x09, 0x01        // Usage (Consumer Control)
    0xA1, 0x01        //   Collection (Application)
    0x85, 0x02        //   Report ID (2)
    0x19, 0x00        //   Usage Minimum (Undefined)
    0x2A, 0x3C, 0x02  //   Usage Maximum (AC Format)
    0x15, 0x00        //   Logical Minimum (0)
    0x26, 0x3C, 0x02  //   Logical Maximum (572)
    0x95, 0x01        //   Report Count (1)
    0x75, 0x10        //   Report Size (16)
    0x81, 0x00        //   Input (Data, Array, Absolute, No Wrap, Linear, Preferred State, No Null Position)
    0xC0              // End Collection"
};

assert_eq!(pretty_print(&items), EXPECTED);

Structs

Collection

A meaningful grouping of Input, Output, and Feature items.

Delimiter

Defines the beginning or end of a set of local items (1 = open set, 0 = close set).

DesignatorIndex

Determines the body part used for a control. Index points to a designator in the Physical descriptor.

DesignatorMaximum

Defines the index of the ending designator associated with an array or bitmap.

DesignatorMinimum

Defines the index of the starting designator associated with an array or bitmap.

EndCollection

A terminating item used to specify the end of a collection of items.

Feature

Describes device input and output not intended for consumption by the end user.

Input

Refers to the data from one or more similar controls on a device.

LogicalMaximum

Extent value in logical units. This is the maximum value that a variable or array item will report.

LogicalMinimum

Extent value in logical units. This is the minimum value that a variable or array item will report.

Output

Refers to the data to one or more similar controls on a device such as setting the position of a single axis or a group of levers (variable data). Or, it can represent data to one or more LEDs (array data).

PhysicalMaximum

Maximum value for the physical extent of a variable item. This represents the Logical Maximum with units applied to it.

PhysicalMinimum

Minimum value for the physical extent of a variable item. This represents the Logical Minimum with units applied to it.

Pop

Replaces the item state table with the top structure from the stack.

Push

Places a copy of the global item state table on the stack.

ReportCount

Unsigned integer specifying the number of data fields for the item; determines how many fields are included in the report for this particular item (and consequently how many bits are added to the report).

ReportId

Unsigned value that specifies the Report ID.

ReportSize

Unsigned integer specifying the size of the report fields in bits.

Reserved

Items that are reserved for future use.

StringIndex

String index for a String descriptor; allows a string to be associated with a particular item or control.

StringMaximum

Specifies the last string index when assigning a group of sequential strings to controls in an array or bitmap.

StringMinimum

Specifies the first string index when assigning a group of sequential strings to controls in an array or bitmap.

Unit

Unit values.

UnitExponent

Value of the unit exponent in base 10.

Usage

Usage index for an item usage; represents a suggested usage for the item or collection.

UsageMaximum

Defines the ending usage associated with an array or bitmap.

UsageMinimum

Defines the starting usage associated with an array or bitmap.

UsagePage

Unsigned integer specifying the current Usage Page.

Enums

HidError

Error type.

ReportItem

Report items enumeration.

Functions

dump

Dump items into a byte stream.

parse

Parse a byte stream into a report item iterator.

parse_strict

Parse a byte stream into a report item iterator in strict mode.

pretty_print

Print items to string in a pretty way.