class V extends View {
        Paint paint = new Paint();
        Random rnd = new Random();
        CatmullRomSpline spline;

        public V(Context context) {
            super(context);
            paint.setColor(Color.GREEN);
            paint.setStrokeWidth(5);
            paint.setStyle(Paint.Style.STROKE);
            paint.setTextSize(64);
        }

        @Override
        protected void onDraw(Canvas canvas) {
            canvas.drawText("Click me", 100, 100, paint);

            int R = 300;
            int NUM_EDGES = 20;
            int NUM_POINTS = 100;

            canvas.translate(getWidth() / 2, getHeight() / 2);
            float[] arr = new float[NUM_EDGES];
            for (int i = 0; i < arr.length; i++) {
                arr[i] = R / 30 * (float) (rnd.nextGaussian());
            }
            spline = new CatmullRomSpline(arr);
            float x0 = Float.NEGATIVE_INFINITY;
            float y0 = Float.NEGATIVE_INFINITY;
            for (int i = 0; i <= NUM_POINTS; i++) {
                double a = i * 2 * Math.PI / NUM_POINTS;
                float r = R + spline.q(i / (float) NUM_POINTS);
                float x = r * (float) Math.sin(a);
                float y = r * (float) Math.cos(a);
                if (x0 != Float.NEGATIVE_INFINITY) {
                    canvas.drawLine(x, y, x0, y0, paint);
                }
                x0 = x;
                y0 = y;
            }
        }

        @Override
        public boolean onTouchEvent(MotionEvent event) {
            invalidate();
            return true;
        }
    }

    // sample output is http://ctrlv.in/524966 or http://ctrlv.in/524967
    public class CatmullRomSpline {
        float[] points;

        public CatmullRomSpline(float[] points) {
            this.points = points;
        }

        public float q(float t) {
            int i = (int) (t * points.length);
            t = t * points.length - i;
            return _q(t, p(i-1), p(i), p(i+1), p(i+2));
        }

        private float p(int i) {
            i = (i + points.length) % points.length;
            return points[i];
        }

        private float _q(float t, float p0, float p1, float p2, float p3) {
            return 0.5f * ((2 * p1) +
                    (p2 - p0) * t +
                    (2 * p0 - 5 * p1 + 4 * p2 - p3) * t * t +
                    (3 * p1 -p0 - 3 * p2 + p3) * t * t * t);
        }
    }