Method GetBoxPropertyData

proxyAudioDevice/ProxyAudioDevice.cpp:1871–2145

}

OSStatus ProxyAudioDevice::GetBoxPropertyData(AudioServerPlugInDriverRef inDriver,
                                              AudioObjectID inObjectID,
                                              pid_t inClientProcessID,
                                              const AudioObjectPropertyAddress *inAddress,
                                              UInt32 inQualifierDataSize,
                                              const void *inQualifierData,
                                              UInt32 inDataSize,
                                              UInt32 *outDataSize,
                                              void *outData) {
#pragma unused(inQualifierDataSize, inQualifierData)

    //    declare the local variables
    OSStatus theAnswer = 0;

    //    check the arguments
    FailWithAction(inDriver != gAudioServerPlugInDriverRef,
                   theAnswer = kAudioHardwareBadObjectError,
                   Done,
                   "GetBoxPropertyData: bad driver reference");
    FailWithAction(
        inAddress == NULL, theAnswer = kAudioHardwareIllegalOperationError, Done, "GetBoxPropertyData: no address");
    FailWithAction(outDataSize == NULL,
                   theAnswer = kAudioHardwareIllegalOperationError,
                   Done,
                   "GetBoxPropertyData: no place to put the return value size");
    FailWithAction(outData == NULL,
                   theAnswer = kAudioHardwareIllegalOperationError,
                   Done,
                   "GetBoxPropertyData: no place to put the return value");
    FailWithAction(inObjectID != kObjectID_Box,
                   theAnswer = kAudioHardwareBadObjectError,
                   Done,
                   "GetBoxPropertyData: not the plug-in object");

    //    Note that for each object, this driver implements all the required properties plus a few
    //    extras that are useful but not required.
    //
    //    Also, since most of the data that will get returned is static, there are few instances where
    //    it is necessary to lock the state mutex.
    switch (inAddress->mSelector) {
        case kAudioObjectPropertyBaseClass:
            //    The base class for kAudioBoxClassID is kAudioObjectClassID
            FailWithAction(inDataSize < sizeof(AudioClassID),
                           theAnswer = kAudioHardwareBadPropertySizeError,
                           Done,
                           "GetBoxPropertyData: not enough space for the return value of kAudioObjectPropertyBaseClass "
                           "for the box");
            *((AudioClassID *)outData) = kAudioObjectClassID;
            *outDataSize = sizeof(AudioClassID);
            break;

        case kAudioObjectPropertyClass:
            //    The class is always kAudioBoxClassID for regular drivers
            FailWithAction(
                inDataSize < sizeof(AudioClassID),
                theAnswer = kAudioHardwareBadPropertySizeError,
                Done,
                "GetBoxPropertyData: not enough space for the return value of kAudioObjectPropertyClass for the box");