RNotifier AppUI class for Bluetooth

[davmt]

Hi, I have a few questions on how this class is operating.
First of all in the SDK there is an example on using this particular class for Bluetooth device discovery.

TBTDeviceSelectionParams selectionFilter;
TBTDeviceSelectionParamsPckg pckg(selectionFilter);
TBTDeviceResponseParams result;
TBTDeviceResponseParamsPckg resultPckg(result);

The above parameters are declared. Now let's say i need the result of the device chosen stored as a private member of a class, rather than in the actual implementation, so I can access the device's data anytime within the GUI, and not within that scope.
1) How and where do I initialize the TBTDeviceResponseParamsPckg variable?

My other question regards getting the Bluetooth 48-bit address and display it to the user through a command menu. BDAddr() returns the address of the device. Now to read the address I use, GetReadable(),

IMPORT_C void GetReadable(TDes &aDest) const;

to "Extract the Bluetooth device address into a human-readable format".

2) What suitable descriptor can be used to store this data. I tried all sorts of descriptors and haven't had luck. USER11, due to the large returned descriptor seems to be the most common problem here.

[symbianyucca]

1. you could maybe check this from teh example you mentioned.

2. Try checking headers, they usually define the actual maximun size somewhere, anyway, for testing you could try TBuf<255>, it is most likely big enough.

[davmt]

1) The following is the example,

// 1. Create a notifier
RNotifier not;
User::LeaveIfError(not.Connect());

// 2. Start the device selection plug-in
TBTDeviceSelectionParams selectionFilter;
TUUID targetServiceClass(0x2345);
selectionFilter.SetUUID(targetServiceClass);
TBTDeviceSelectionParamsPckg pckg(selectionFilter);
TBTDeviceResponseParams result;
TBTDeviceResponseParamsPckg resultPckg(result);
TRequestStatus status;
not.StartNotifierAndGetResponse(status, KDeviceSelectionNotifierUid, pckg, resultPckg);
User::After(2000000);

// 3. Extract device name if it was returned
User::WaitForRequest(status);
TPtrC name;
if (status.Int() == KErrNone)
    {
    if (resultPckg.IsValidDeviceName())
        {
     name.Set(resultPckg().DeviceName());
        }
    }
    
// 4. Clean up
not.CancelNotifier(KDeviceSelectionNotifierUid);
not.Close();

So for clarification could you maybe tell me the actual use of package buffers?
Are they only being used because the not.StartNotifierAndGetResponse(status, KDeviceSelectionNotifierUid, pckg, resultPckg) function takes only a packaged buffer. If yes my next question would be how do I open a package buffer to reassign the value to the TBTDeviceResponseParams result parameter.

2) Ok so I set, TBuf<255> iAddress;

	if (status.Int() == KErrNone)
		{
			if (resultPckg().IsValidBDAddr())		
			{
				iBTState = EBTDiscoveredDevice;
				//iDevice = resultPckg().DeviceName();
				resultPckg().BDAddr().GetReadable(iAddress);
			}
		}

and get the error BTDevAddr 0

[wizard_hu_]

What is iAddress?

[davmt]

iAddress is declared in BtEngine.h(of course included in the corresponding cpp file) as
TBuf<255> iAddress;

So it's a large stack based descriptor. Convention wise, this should be simply declared as address or iAddress?

class CBTEngine : public CBase
{
public:
	static CBTEngine* NewL(MBTObserve& aMBTObserve);
	~CBTEngine();
	TBTState BTState()
		{
			return iBTState;
		}
	void DiscoverDevicesL();
	void DiscoverServicesL();
	virtual void HandleBTEngineState();
	TDesC& GetDeviceNameL();
	TDesC& GetDeviceAddressL();
private:
	//TBuf<48> iDevice;
	TPtrC tempPtr;
	HBufC* iDevice;
	TBuf<255> iAddress;
	TBTState iBTState;
	CBTEngine(MBTObserve& aMBTObserve);
	void ConstructL();
	MBTObserve& iMBTObserve;
};

EDIT: iAddress will therefore be the descriptor containing the human readable format of the Bluetooth Address' device being selected.

[wizard_hu_]

Sorry, I have not noticed that you have specified it in "2)".
A strange thing is your filter: are you sure about that service 0x2345 actually exists on your devices?

[davmt]

The filter ain't the problem, I commented it to make the selection parameters default. But with the filter(I took it from the example code) or without that filter my devices are being found in the notifier.