doctor_app_flutter/lib/widgets/auth/auth_header.dart

import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
import 'package:flutter_device_type/flutter_device_type.dart';

class AuthHeader extends StatelessWidget {
  const AuthHeader({
    Key key,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    print(Device.get().isPhone);
    print(Device.get().isAndroid);
    print(Device.get().isIos);

    

    var smallScreenSize = 660;
    return LayoutBuilder(builder: (ctx, constraints) {
      
      bool isSmallScreen = constraints.maxWidth<=smallScreenSize;
      var screen = Container(
      margin:  isSmallScreen?null:EdgeInsetsDirectional.fromSTEB(constraints.maxWidth*0.30, constraints.maxWidth*0.1, 0, 0),
        child: Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: <Widget>[
        Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: <Widget>[
            Container(
              margin: isSmallScreen?EdgeInsetsDirectional.fromSTEB(0, 50, 0, 0):EdgeInsetsDirectional.fromSTEB(constraints.maxWidth*0.13, 0, 0, 0),
              child: Image.asset(
                'assets/images/login_icon.png',
                fit: BoxFit.cover,
                height: isSmallScreen?null: constraints.maxWidth*0.09,
              ),
            ),
            SizedBox(
              height: 10,
            ),
            Container(
              margin: isSmallScreen?null:EdgeInsetsDirectional.fromSTEB(constraints.maxWidth*0.13, 0, 0, 0),
              child: Text(
                "LOGIN",
                style: TextStyle(fontSize: isSmallScreen?30:constraints.maxWidth*0.035, fontWeight: FontWeight.w800),
              ),
            )
          ],
        ),
        Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          
          children: isSmallScreen?<Widget>[
            SizedBox(
              height: 10,
            ),
            Text(
              "Welcome to",
              style: TextStyle(fontSize: isSmallScreen?24:constraints.maxWidth*0.029),
            ),
            Text(
              'Dr Sulaiman Al Habib',
              style: TextStyle(
                fontSize: isSmallScreen?24:constraints.maxWidth*0.029,
                color: Theme.of(context).primaryColor,
              ),
            ),
            
          ]:<Widget>[SizedBox(
              height: 10,
            ),Row(
              mainAxisAlignment: MainAxisAlignment.start,
              children: <Widget>[
                Text(
              "Welcome to ",
              style: TextStyle(fontSize: isSmallScreen?24:constraints.maxWidth*0.029),
            ),
            Text(
              'Dr Sulaiman Al Habib',
              style: TextStyle(
                fontSize: isSmallScreen?24:constraints.maxWidth*0.029,
                color: Theme.of(context).primaryColor,
              ),
            ),
              ],
            ),Container(
               margin: isSmallScreen?null:EdgeInsetsDirectional.fromSTEB(constraints.maxWidth*0.13, 0, 0, 0),
              child: Text(
                "Doctor App",
                style: TextStyle(
                    fontSize: isSmallScreen?26:constraints.maxWidth*0.030, color: Theme.of(context).primaryColor),
              ),
            )],
        )
      ],
    ));
      return screen;
    });
  }
}