Set border when animating as border Layout?

Question

Java

I have a dozen objects that move around the screen and all are set within the same RelativeLayout. I did the selection of coordinates by eye, tried all sorts of .getWidth and so on, but the effect was zero.

How can I set the border of movement, for example from the left edge to the right edge of my RelativeLayout?

button5 = ObjectAnimator.ofPropertyValuesHolder(pr5,
     PropertyValuesHolder.ofFloat("x", 0, 910),
     PropertyValuesHolder.ofFloat("y", 900, 900));
      button5.setDuration(5300+getSpeed_a());
       button5.setRepeatCount(ObjectAnimator.INFINITE);
       button5.setRepeatMode(ObjectAnimator.REVERSE);