overflowScroll method

ScrollBuilder overflowScroll()

overflow-scroll -> 始终显示滚动（双向滚动）

Implementation

ScrollBuilder overflowScroll() {
  _enableScrollX = true;
  _enableScrollY = true;
  _clipBehavior = Clip.hardEdge;
  _physics = const AlwaysScrollableScrollPhysics();
  return this;
}