flutter line text

line_text.dart

import 'package:flutter/material.dart';
import 'package:flutter/semantics.dart';

class LineText extends CustomPainter {
  final String text;
  final TextStyle style;
  final double padding;
  final Color strokeColor;
  final double strokeWidth;
  final Alignment alignment;

  LineText(
      {this.text,
      this.style,
      this.padding = 12.0,
      this.strokeColor = Colors.black,
      this.strokeWidth = 1.0,
      this.alignment});

  @override
  void paint(Canvas canvas, Size size) {
    final TextPainter tp = TextPainter(
        text: TextSpan(
            text: this.text,
            style: this
                .style
                .merge(TextStyle(textBaseline: TextBaseline.ideographic))),
        textDirection: TextDirection.ltr,
        textAlign: TextAlign.start)
      ..layout();

    final Offset offset = alignment.alongSize(size);
    final double start = (size.width - tp.width) / 2.0 - padding;
    final double extent = tp.width + (padding * 2);
    final Path path = Path()
      ..moveTo(0.0, offset.dy)
      ..lineTo(start, offset.dy)
      ..relativeMoveTo(extent, 0.0)
      ..lineTo(size.width, offset.dy);

    canvas.drawPath(
        path,
        Paint()
          ..color = this.strokeColor
          ..strokeWidth = this.strokeWidth
          ..style = PaintingStyle.stroke);

    tp.paint(canvas, Offset((size.width - tp.width) / 2.0, -(tp.height) / 2 + offset.dy));
  }

  @override
  SemanticsBuilderCallback get semanticsBuilder {
    return (Size size) {
      var rect = Offset.zero & size;
      var width = size.shortestSide * 0.4;
      rect = const Alignment(0.8, -0.9).inscribe(Size(width, width), rect);
      return [
        CustomPainterSemantics(
          rect: rect,
          properties: SemanticsProperties(
            label: this.text,
            textDirection: TextDirection.ltr,
          ),
        ),
      ];
    };
  }

  @override
  bool shouldRepaint(LineText oldDelegate) => false;
  @override
  bool shouldRebuildSemantics(LineText oldDelegate) => false;
}

CustomPaint(
    painter: LineText(
        alignment: Alignment.center,
        text: 'label',
        style: TextStyle(color: Colors.white),
        strokeColor: Colors.white54))

----- label -----