PhoneStateListener in background thread

Question

I'm having an issue in trying to run a PhoneStateListener on* callback methods in a backround thread. Here's what I did so far:

First, I wrote my PhoneStateListener implementation. Something on the lines of:

public MyPhoneStateListener extends PhoneStateListener {
    private TelephonyManager mTelephonyManager;

    public MyPhoneStateListener(Context context) {
        mTelephonyManager = (TelephonyManager) context.getSystemServices(Context.TELEPHONY_SERVICE);
    }

    @Override
    public void onCallStateChanged(int state, String incomingNumber) { ... }

    public void startListening() {
        mTelephonyManager.listen(this, PhoneStateListener.LISTEN_CALL_STATE);
    }
}

Then I created a Handler class:

public PhoneStateHandler extends Handler {
    private Context mContext;
    private MyPhoneStateListener mListener;

    public static final int MESSAGE_START = 0;

    public PhoneStateHandler(Context context, Looper looper) {
        super(looper);
        mContext = context;
    }

    @Override
    public void onHandleMessage(Message message) {
        if (mListener == null) {
            mListener = new MyPhoneStateListener(mContext);
        }

        switch (message.what) {
        case MESSAGE_START:
            mListener.startListening();
            break;
        }
    }
}

Finally, from within a Service I start a new HandlerThread and attach my PhoneStateHandler to its' looper:

HandlerThread mThread = new HandlerThread("PhoneStateListenerThread");
mThread.start();
PhoneStateHandler mHandler = new PhoneStateHandler(this, mThread.getLooper());
mHandler.sendMessage(Message.obtain(mHandler, PhoneStateHandler.MESSAGE_START));

What I expect, is that methods such as MyPhoneStateListener.onCallStateChanged() to be executed on the mThread thread instead of the UI thread. I'm exploiting the fact that when a PhoneStateListener is first created, it is bound to the Looper of its current thread. This is undocumented, but that's what actually happens.

What I observed, however, is that despite the PhoneStateHandler.onHandleMessage() method gets called in the HandlerThread's looper (as I expect), the MyPhoneStateListener.onCallStateChanged() still gets called in the UI thread.

Any clue about what's wrong with my code?

Thanks

Cheque

Any solutions ? – Ducat