renderOverlay method

Implementation

Widget renderOverlay() {
  return Positioned.fill(
      child: Container(
          decoration: BoxDecoration(
    borderRadius: BorderRadius.circular(12),
    gradient: LinearGradient(
      begin: Alignment.topCenter,
      end: Alignment.bottomCenter,
      colors: [
        Colors.transparent,
        Colors.black.withOpacity(0.55),
      ],
    ),
  )));
}