Border.all({Color color: const Color(0xFF000000), double width: 1.0, BorderStyle style: BorderStyle.solid })

A uniform border with all sides the same color and width.

Source 

factory Border.all({
  Color color: const Color(0xFF000000),
  double width: 1.0,
  BorderStyle style: BorderStyle.solid
}) {
  final BorderSide side = new BorderSide(color: color, width: width, style: style);
  return new Border(top: side, right: side, bottom: side, left: side);
}