// This code example shows all HID Function Driver events and a possible
// scheme for handling these events. In this example event responses are not
// deferred.

USB_DEVICE_HID_EVENT_RESPONSE USB_AppHIDEventHandler
(
    USB_DEVICE_HID_INDEX instanceIndex, 
    USB_DEVICE_HID_EVENT event, 
    void * pData,
    uintptr_t userData
)
{
    uint8_t currentIdleRate;
    uint8_t someHIDReport[128];
    uint8_t someHIDDescriptor[128];
    USB_DEVICE_HANDLE       usbDeviceHandle;
    USB_HID_PROTOCOL_CODE  currentProtocol;
    USB_DEVICE_HID_EVENT_DATA_GET_REPORT        * getReportEventData;
    USB_DEVICE_HID_EVENT_DATA_SET_IDLE          * setIdleEventData;
    USB_DEVICE_HID_EVENT_DATA_SET_DESCRIPTOR    * setDescriptorEventData;
    USB_DEVICE_HID_EVENT_DATA_SET_REPORT        * setReportEventData;

    switch(event)
    {
        case USB_DEVICE_HID_EVENT_GET_REPORT:

            // In this case, pData should be interpreted as a
            // USB_DEVICE_HID_EVENT_DATA_GET_REPORT pointer. The application
            // must send the requested report by using the
            // USB_DEVICE_ControlSend() function. 

            getReportEventData = (USB_DEVICE_HID_EVENT_DATA_GET_REPORT *)pData;
            USB_DEVICE_ControlSend(usbDeviceHandle, someHIDReport, getReportEventData->reportLength);

            break;

        case USB_DEVICE_HID_EVENT_GET_PROTOCOL:

            // In this case, pData will be NULL. The application
            // must send the current protocol to the host by using
            // the USB_DEVICE_ControlSend() function.

           USB_DEVICE_ControlSend(usbDeviceHandle, &currentProtocol, sizeof(USB_HID_PROTOCOL_CODE)); 
           break;
            
        case USB_DEVICE_HID_EVENT_GET_IDLE:

            // In this case, pData will be a
            // USB_DEVICE_HID_EVENT_DATA_GET_IDLE pointer type containing the
            // ID of the report for which the idle rate is being requested.
            // The application must send the current idle rate to the host
            // by using the USB_DEVICE_ControlSend() function.

           USB_DEVICE_ControlSend(usbDeviceHandle, &currentIdleRate, 1); 
           break;

        case USB_DEVICE_HID_EVENT_SET_REPORT:
            
            // In this case, pData should be interpreted as a
            // USB_DEVICE_HID_EVENT_DATA_SET_REPORT type pointer. The
            // application can analyze the request and then obtain the
            // report by using the USB_DEVICE_ControlReceive() function.

            setReportEventData = (USB_DEVICE_HID_EVENT_DATA_SET_REPORT *)pData;
            USB_DEVICE_ControlReceive(deviceHandle, someHIDReport, setReportEventData->reportLength);
            break;

        case USB_DEVICE_HID_EVENT_SET_PROTOCOL:

            // In this case, pData should be interpreted as a 
            // USB_DEVICE_HID_EVENT_DATA_SET_PROTOCOL type pointer. The application can
            // analyze the data and decide to stall or accept the setting.
            // This shows an example of accepting the protocol setting.

            USB_DEVICE_ControlStatus(deviceHandle, USB_DEVICE_CONTROL_STATUS_OK);
            break;
        
        case USB_DEVICE_HID_EVENT_SET_IDLE:
        
            // In this case, pData should be interpreted as a 
            // USB_DEVICE_HID_EVENT_DATA_SET_IDLE type pointer. The
            // application can analyze the data and decide to stall
            // or accept the setting. This shows an example of accepting
            // the protocol setting.

            setIdleEventData = (USB_DEVICE_HID_EVENT_DATA_SET_IDLE *)pData;
            USB_DEVICE_ControlStatus(deviceHandle, USB_DEVICE_CONTROL_STATUS_OK);
            break;

        case USB_DEVICE_HID_EVENT_CONTROL_TRANSFER_DATA_RECEIVED:

            // In this case, control transfer data was received. The 
            // application can inspect that data and then stall the
            // handshake stage of the control transfer or accept it
            // (as shown here).
            
            USB_DEVICE_ControlStatus(deviceHandle, USB_DEVICE_CONTROL_STATUS_OK);
            break;

        case USB_DEVICE_HID_EVENT_CONTROL_TRANSFER_DATA_SENT:
            
            // This means that control transfer data was sent. The
            // application would typically acknowledge the handshake
            // stage of the control transfer.

            break;

        case USB_DEVICE_HID_EVENT_CONTROL_TRANSFER_ABORTED:

            // This is an indication only event. The application must
            // reset any HID control transfer related tasks when it receives
            // this event.

        break;

        case USB_DEVICE_HID_EVENT_REPORT_RECEIVED:
            
            // This means a HID report receive request has completed.
            // The pData member should be interpreted as a 
            // USB_DEVICE_HID_EVENT_DATA_REPORT_RECEIVED pointer type. 
            
            break;

        case USB_DEVICE_HID_EVENT_REPORT_SENT:
            
            // This means a HID report send request has completed.
            // The pData member should be interpreted as a 
            // USB_DEVICE_HID_EVENT_DATA_REPORT_SENT pointer type. 
            
            break;
    }

    return(USB_DEVICE_HID_EVENT_RESPONSE_NONE);
}