Class hierarchies

-----------------

MIDIDriver

    USBMIDIDriverBase

        USBVendorMIDIDriver

            CompanyA_USBMIDIDriver

            CompanyB_USBMIDIDriver

            etc.

        USBMIDIClassDriver

    SerialMIDIDriverBase *

        StandardSerialMIDIDriver

        CompanyC_SerialMIDIDriver

        CompanyD_SerialMIDIDriver

        etc.

MIDIDriverDevice  (was: InterfaceState)

    USBMIDIDevice

    SerialMIDIDevice *

IOServiceManager

    USBDeviceManager

        USBMIDIDeviceManager

    USBInterfaceManager

        USBMIDIClassInterfaceManager

    SerialDeviceManager *

* doesn't exist yet

Vendor-specific drivers not supplied by Apple.

Object ownership hierarchy

--------------------------

USBVendorMIDIDriver

    USBMIDIDeviceManager

        array of USBMIDIDevice

with ALL vendor-specific overrides implemented in the driver class

although the device may also be subclassed in special cases