borderRadius property
Clips the whole size bounding box to this shape. A rounded
Material sized to exactly fill that box (as the floating window
does) still leaves this box's own four corners uncovered — a
rounded shape inscribed in a same-sized square doesn't reach into
the square's corners — so anything painted behind it within this
widget (the Overlay beneath the window's content clips to a hard
rectangular edge by default) shows through there unless this outer
box is rounded to match. Defaults to no rounding, since the bubble
is already a circle with nothing behind it to leak through.
Implementation
final BorderRadius borderRadius;