Track velocity in list view

listview_velocity_tracker

@Override
        public boolean onTouchEvent(MotionEvent event) {
            int action = event.getAction();
            switch(action) {
                case MotionEvent.ACTION_DOWN:
                    if(vTracker == null) {
                        vTracker = VelocityTracker.obtain();
                    }
                    else {
                        vTracker.clear();
                    }
                    vTracker.addMovement(event);
                    break;
                case MotionEvent.ACTION_MOVE:
                    vTracker.addMovement(event);
                    vTracker.computeCurrentVelocity(1000);
                    Log.v("", "X velocity is " + vTracker.getXVelocity() +" pixels per second");
                    Log.v("", "Y velocity is " + vTracker.getYVelocity() +" pixels per second");
                    break;
                case MotionEvent.ACTION_UP:
                case MotionEvent.ACTION_CANCEL:
                    vTracker.recycle();
                    break;
            }
            return super.onTouchEvent(event);
        }