Trapezoid shape with rounded corners

rounded_trapezoid_painter.dart

import 'dart:math' as math;
 
class RoundedTrapezoidShapePainter extends CustomPainter {
  /// BackgroundColor of the shape
  ///
  final Color? color;
 
  /// Radius of the topRight and topLeft corners
  ///
  final double radius;
 
  /// Subtracted from the height of the painter to get the height
  /// of the short side.
  ///
  final double shortSideDifference;
 
  RoundedTrapezoidShapePainter({
    required this.shortSideDifference,
    required this.radius,
    this.color,
  });
  @override
  void paint(Canvas canvas, Size size) {
    final width = size.width;
    final height = size.height;
    final paint = Paint()
      ..color = color ?? Colors.transparent
      ..strokeWidth = 1
      ..style = PaintingStyle.fill;
 
    final path = Path()
      ..arcTo(Rect.fromLTWH(0, 0, radius * 2, radius * 2), math.pi, math.pi / 2,
          false)
      ..arcTo(Rect.fromLTWH(width - radius * 2, 0, radius * 2, radius * 2),
          -math.pi / 2, math.pi / 2, false)
      ..lineTo(width, height)
      ..lineTo(0, height - shortSideDifference);
 
    canvas.drawPath(path, paint);
  }
 
  @override
  bool shouldRepaint(RoundedTrapezoidShapePainter oldDelegate) {
    return color != oldDelegate.color;
  }
}