gistfile1.txt

    private class SpringFingerFollow implements OnTouchListener {

        private final Point mScreenSize;
        private Spring mSpringX;
        private Spring mSpringY;

        private SpringConfig mSpringConfig = new SpringConfig(30, 8);
        private VelocityTracker mVelocityTracker;

        private SpringFingerFollow() {
            SpringSystem springSystem = SpringSystem.create();
            mSpringX = springSystem.createSpring();
            mSpringX.addListener(new SimpleSpringListener() {

                @Override
                public void onSpringUpdate(Spring spring) {
                    int value = (int) spring.getCurrentValue();
                    Log.d("ACHTUNG springX", "cur value: " + value);
                    windowManager.updateViewLayout(FlyingBall.this, params);
                    params.x = value;
                    invalidate();
                }
            });
            mSpringY = springSystem.createSpring();
            mSpringY.addListener(new SimpleSpringListener() {

                @Override
                public void onSpringUpdate(Spring spring) {
                    int value = (int) spring.getCurrentValue();
                    Log.d("ACHTUNG springY", "cur value: " + value);
                    windowManager.updateViewLayout(FlyingBall.this, params);
                    params.y = value;
                    invalidate();
                }
            });

            mSpringX.setSpringConfig(mSpringConfig);
            mSpringY.setSpringConfig(mSpringConfig);

            Display display = windowManager.getDefaultDisplay();
            mScreenSize = new Point();
            display.getSize(mScreenSize);
        }

        @Override
        public boolean onTouch(View v, MotionEvent event) {
            Log.d("ACHTUNG touch", "x:" + event.getRawX() + ", y:" + event.getRawY() + "(" + event.getAction() + ")");
            switch (event.getAction()) {
                case MotionEvent.ACTION_DOWN:
                    mVelocityTracker = VelocityTracker.obtain();
                    mVelocityTracker.addMovement(event);
                    break;
                case MotionEvent.ACTION_MOVE:
                    mSpringX.setEndValue(event.getRawX());
                    mSpringY.setEndValue(event.getRawY());

                    mVelocityTracker.addMovement(event);
                    break;
                case MotionEvent.ACTION_UP:
                    mVelocityTracker.addMovement(event);
                    double velocityX = mSpringX.getVelocity();
                    double velocityY = mSpringY.getVelocity();
                    Point destinationPoint = computeDestinationPoint(((int)velocityX), ((int)velocityY));

//                    mVelocityTracker.computeCurrentVelocity(1000);
//                    int xVelocity = (int) mVelocityTracker.getXVelocity();
//                    int yVelocity = (int) mVelocityTracker.getYVelocity();
//                    Toast.makeText(getContext(), "Vx=" +xVelocity + ", Vy=" + yVelocity, Toast.LENGTH_SHORT).show();
//                    Point destinationPoint = computeDestinationPoint(30, 15);

//                    Point destinationPoint = computeDestinationPoint(30, 15);
                    mSpringX.setEndValue(destinationPoint.x);
                    mSpringY.setEndValue(destinationPoint.y);
                    break;
            }
            return false;
        }

        private Point computeDestinationPoint(int velocityX, int velocityY) {
            double timeX = getTimeOfArrivalOnAxis(params.x, velocityX, true);
            double timeY = getTimeOfArrivalOnAxis(params.y, velocityY, false);

            double time = timeX < timeY ? timeX : timeY;

            int distanceX = (int) (time * velocityX);
            int distanceY = (int) (time * velocityY);

            return new Point(params.x + distanceX, params.y + distanceY);
        }

        private double getTimeOfArrivalOnAxis(int currentPositionOnAxis, int velocity, boolean isAxisX) {
            if (velocity == 0.0) {
                return Double.MAX_VALUE;
            }
            int lastPosition;
            if (velocity > 0) {
                lastPosition = isAxisX ? mScreenSize.x : mScreenSize.y;
            } else {
                lastPosition = 0;
            }

            int distance = lastPosition - currentPositionOnAxis;
            return ((double)distance) / velocity;
        }
    }