TextTabBarLineIndicator.dart

import 'package:flutter/material.dart';

class TextTabBarLineIndicator extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Column(
      mainAxisAlignment: MainAxisAlignment.end,
      crossAxisAlignment: CrossAxisAlignment.start,
      children: <Widget>[
        TabBar(
          indicator: UnderlineTabIndicator(
            borderSide: BorderSide(width: 2, color: Colors.white),
          ),
          labelColor: Colors.white,
          labelStyle: TextStyle(decorationColor: Colors.grey),
          unselectedLabelColor: Colors.white54,
          tabs: [
            ConstrainedBox(
                constraints: BoxConstraints.expand(height: 40),
                child: Center(
                    child: Text(
                      'Login',
                      style: TextStyle(
                          fontFamily: 'Assistant',
                          fontSize: 16,
                          fontWeight: FontWeight.w600),
                    ))),
            ConstrainedBox(
                constraints: BoxConstraints.expand(height: 40),
                child: Center(
                    child: Text(
                      'Signup',
                      style: TextStyle(
                          fontFamily: 'Assistant',
                          fontSize: 16,
                          fontWeight: FontWeight.w600),
                    ))),
          ],
        )
      ],
    );
  }
}