The problem is you have an infinite loop due to BigCircle
width
and height
being adjusted based on its size
(width, height). Try changing your BigCircle
to:
<BigCircle>
canvas:
Color:
rgb: 1, 1, 0
Ellipse:
size: min(self.size), min(self.size)
pos: root.center_x - min(self.size)/2, root.center_y - min(self.size)/2