Android : When add messages for Echo Server with Socket

My app must draw lines green color and send drawing data to echo server, when server get answer re-draw green line on black. So i don't know where i have to send messages to server, because when i do ACTION_UP, sending stops. My code:

public class MyActivity extends Activity{

private WebSocketClient mWebSocketClient;
private Paint mPaint;
private Paint socketPaint;
private Path socketPath;
private Bitmap mBitmap;
private Canvas mCanvas;
private Path mPath;
private LinkedList<String> socketMessages;
private String[] tokens;
private String comma = "[,]";

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(new MyView(this));

    mPaint = new Paint();
    mPaint.setColor(Color.GREEN);
    mPaint.setStyle(Paint.Style.STROKE);
    mPaint.setStrokeWidth(1);

    socketPaint = new Paint();
    socketPaint.setColor(Color.BLACK);
    socketPaint.setStyle(Paint.Style.STROKE);
    socketPaint.setStrokeWidth(3);
    socketMessages = new LinkedList<String>();
    connectWebSocket();
}

public void connectWebSocket() {
    URI uri = null;
    try {
        uri = new URI("ws://echo.websocket.org");
    } catch (URISyntaxException e) {
        e.printStackTrace();
    }

    mWebSocketClient = new WebSocketClient(uri) {

        @Override
        public void onOpen(ServerHandshake handshakedata) {
            Log.i("Websocket", "Opened");

        }

        @Override
        public void onMessage(String s) {
            final String message = s;
            runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    tokens = message.split(comma);
                    socketPath.moveTo(Float.valueOf(tokens[0]), Float.valueOf(tokens[1]));
                    socketPath.quadTo(Float.valueOf(tokens[2]), Float.valueOf(tokens[3]), (Float.valueOf(tokens[2]) + Float.valueOf(tokens[0]))/2, (Float.valueOf(tokens[3]) + Float.valueOf(tokens[1]))/2);
                    socketPath.lineTo(Float.valueOf(tokens[2]), Float.valueOf(tokens[3]));
                    mCanvas.drawPath(socketPath, socketPaint);
                    socketPath.reset();
                }
            });
        }

        @Override
        public void onClose(int code, String reason, boolean remote) {
            Log.i("Websocket", "Closed " + reason);

        }

        @Override
        public void onError(Exception ex) {
            Log.i("Websocket", "Error " + ex.getMessage());
        }
    };
    mWebSocketClient.connect();
}

public void sendMessages(){

    while(!socketMessages.isEmpty()){
        mWebSocketClient.send(socketMessages.getFirst());
        if(!socketMessages.isEmpty())
        socketMessages.removeFirst();
    }
}

public class MyView extends View {

    private float mX, mY;

    public MyView(Context c) {
        super(c);
        mPath = new Path();
        socketPath = new Path();
    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        mBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
        mCanvas = new Canvas(mBitmap);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        canvas.drawColor(Color.WHITE);
        canvas.drawBitmap(mBitmap, 0, 0, mPaint);
        canvas.drawPath(mPath, mPaint);
        canvas.drawPath(socketPath, socketPaint);
    }

    private void touch_start(float x, float y) {
        mPath.reset();
        mPath.moveTo(x, y);
        mX = x;
        mY = y;
    }

    private void touch_move(float x, float y) {
        mPath.quadTo(mX, mY, (x + mX)/2, (y + mY)/2);

//Maybe here LinkedList doesn't have enough time

socketMessages.add(String.valueOf(mX) + "," +String.valueOf(mY) + "," + String.valueOf(x) + "," + String.valueOf(y));
        mX = x;
        mY = y;

    }

    private void touch_up() {
        mPath.lineTo(mX, mY);
        mCanvas.drawPath(mPath, mPaint);
        mPath.reset();
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        float x = event.getX();
        float y = event.getY();

        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                touch_start(x, y);
                invalidate();
                break;
            case MotionEvent.ACTION_MOVE:
                touch_move(x, y);

//Or here when touch event done, this method not working

                sendMessages();
                invalidate();
                break;
            case MotionEvent.ACTION_UP:
                touch_up();
                invalidate();
                break;
        }
        return true;
    }
}

}