BoxShape enum Null safety
Consider using ShapeBorder subclasses directly (with ShapeDecoration), instead of using BoxShape and Border, if the shapes will need to be interpolated or animated. The Border class cannot interpolate between different shapes.
- rectangle → const BoxShape
- circle → const BoxShape
A circle centered in the middle of the box into which the Border or BoxDecoration is painted. The diameter of the circle is the shortest dimension of the box, either the width or the height, such that the circle touches the edges of the box.