title: Animate custom object variable
body: <p>Let's say I have a custom object, like a Point class (I am not using the one from Android), and I need to slowly change its coordinates from a start value to an end value when the user double taps the screen. I have already all setup, but I can't get to "animate" this change. Do you know how I can do it?</p>
  
  <p>I have already tried something like this, but got no change:
  ObjectAnimator(point, "point.variable", final_value).start()</p>