This package is a Swift interface into C-library "hidapi" designed to swiftify working with HID devices. The product of this package is a dynamic library. Users of the library must import HIDEngine into thier projects.

Add this swift package to your Xcode project. Users of the library can inistantiate HIDControlleror with a device's vendor and product ids which will enable:

- access to hid interface of usb devices 
- inspecting device information
- sending and receiving hid data to and from a usb device

Users of the library can also choose to subclass HIDController, which will similarly enable the above and allow for writing code that is specific to the device at hand.

This package has been devoloped on macOS v10.15 and requires macOS v10.15 as minimum OS requirement.

These libraries must be installed on your system. Using homebrew is the easyest way to install:

- libtool
- hidapi

in terminal: brew install libtool hidapi

The library takes care in the background of managing the library objects and the memory management associated with C-library hidapi. examples of what is automatically taken care of:

- searching the system for a device
- initializing and releasing hidapi library
- opening and closing a device

with the vendor and product IDs of a device, users of the library can query the device properties and send/receive data to and from a device.

Device properties include:

- vendor id
- product id
- device path
- device name
- device manufacturer name
- device serial number 
- and more.

In some cases a user may want to parse incoming data and format outgoing data or validate data in a certain way that is specefic to a device.

The implementation of send/receive algorithms in the HIDController class makes a check to see if a parser and/or a formatter are attached to the controller. if a parser and/or formatter exists, data is passed through them before returning incoming data to the user or sending outgoing data to the device. if no parser/formatter exists, the controller returns the incoming data as received and sends outgoing data also as received from the user.

Users of the library can create device specific parser/formatter by adopting the HIDParser and/or the HIDFormatter protocols. then set these custom parser and formatter in the controller using: setParser and setFormatter methods of the controller. this will pass the hid data through the custom parser/formatter objects.

import HIDEngine

/* use utility function to print information about every hid device attached to the computer */

displayAllAttachedHidDevices()

// to work with a specific device 

/* inistantiaate a controller instance with device ids */
if let controller = HIDController(vendorID: XXXX, productID: XXXX)  {
    
    /* query the device properties */
    print("found controller for device \(controller.productString!)")
    print("vendor id: \(controller.vendorID!)")
    print("product id: \(controller.productID!)")
    print("manufacturer: \(controller.manufacturerString!)")
    print("serial number: \(controller.serialNumber!)")
    print("release number: \(controller.releaseNumber!)")
    print("usage page: \(controller.usagePage!)")
    print("usage: \(controller.usage!)")
    print("path: \(controller.path!)")
    print("interface number: \(controller.interfaceNumber!)")

    /* create app loop */
    outerLoop: while true {

        /* receive and print data from device */
        let data = controller.receive()
        print(data)
        // print(data.count)
        
        /* break out of the app loop with a condition */
        if CONDITION {
            break outerLoop
        }
    }
} else {
    print("Device not found")
}