check for special characters and others

Widget build(BuildContext context) {
  return Scaffold(
    appBar: AppBar(title: Text('IntrinsicWidth')),
    body: Center(
      child: IntrinsicHeight(
        child: Row(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: <Widget>[
            RaisedButton(
              onPressed: () {},
              child: Text('Short'),
            ),
            RaisedButton(
              onPressed: () {},
              child: Text('A bit Longer'),
            ),
            RaisedButton(
              onPressed: () {},
              child: Text('The Longest text button'),
            ),
          ],
        ),
      ),
    ),
  );
}

import 'package:flutter/material.dart';

void main() {
  runApp(
    new MaterialApp(
      title: 'Hello World App',
      home: new myApp(),
    )
  );
}

class myApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: new AppBar(
        title: new Text('Hello World App'),
      ),
      body: new Center(
        child: new Text(
          'Hello, world!'
        ),
      ),
    );
  }
}

MaterialApp(
 debugShowCheckedModeBanner: false
)

Widget build(BuildContext context) {
  return Scaffold(
    appBar: AppBar(title: Text('IntrinsicWidth')),
    body: Center(
      child: IntrinsicWidth(
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: <Widget>[
            RaisedButton(
              onPressed: () {},
              child: Text('Short'),
            ),
            RaisedButton(
              onPressed: () {},
              child: Text('A bit Longer'),
            ),
            RaisedButton(
              onPressed: () {},
              child: Text('The Longest text button'),
            ),
          ],
        ),
      ),
    ),
  );
}

String capitalize(String s) {
  if (s == null || s.isEmpty) {
    return s;
  }
  return s.length < 1 ? s.toUpperCase() : s[0].toUpperCase() + s.substring(1);
}

Text("Border test",
    style: TextStyle(
      inherit: true,
      fontSize: 48.0,
      color: Colors.pink,
      shadows: [
        Shadow( // bottomLeft
          offset: Offset(-1.5, -1.5),
          color: Colors.white
        ),
        Shadow( // bottomRight
          offset: Offset(1.5, -1.5),
          color: Colors.white
        ),
        Shadow( // topRight
          offset: Offset(1.5, 1.5),
          color: Colors.white
        ),
        Shadow( // topLeft
          offset: Offset(-1.5, 1.5),
          color: Colors.white
        ),
      ]
    ),
);

Widget build(BuildContext context) {
  return Scaffold(
    appBar: AppBar(title: Text('IntrinsicWidth')),
    body: Center(
      child: IntrinsicWidth(
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: <Widget>[
            RaisedButton(
              onPressed: () {},
              child: Text('Short'),
            ),
            RaisedButton(
              onPressed: () {},
              child: Text('A bit Longer'),
            ),
            RaisedButton(
              onPressed: () {},
              child: Text('The Longest text button'),
            ),
          ],
        ),
      ),
    ),
  );
}

hasSpecialCharacters = password.contains(new RegExp(r'[!@#$%^&*(),.?":{}|<>]')); 

  final bool isNumeric = password.contains(RegExp('[0-9]'));
  final bool isLowerCase = password.contains(RegExp("(?:[^a-z]*[a-z]){1}"));
  final bool isUpperCase = password.contains(RegExp("(?:[^A-Z]*[A-Z]){1}"));

Container(
                                child: Text(
                                  items[index].itemName,
                                  style: TextStyle(
                                      color: Colors.black, fontSize: 30),
                                  textAlign: TextAlign.center,
                                ), //Text
                                height: 40,
                                width: 400,
                                  decoration:
                               BoxDecoration(
                  border: Border.all(color: Colors.black38, width: 3),
                  borderRadius: BorderRadius.circular(20),
                  boxShadow: [
                    BoxShadow(
                      color: Colors.black.withOpacity(0.5),
                      spreadRadius: 5,
                      blurRadius: 5,
                      offset: Offset(0, 3), // changes position of shadow
                    ),
                  ],
                  color: Colors.white,
                  image: DecorationImage(
                    image: AssetImage(filterList[index].itemImg),
                    fit: BoxFit.contain,
                  ),
                ),

final List<String> entries = <String>['A', 'B', 'C'];
final List<int> colorCodes = <int>[600, 500, 100];

ListView.separated(
  padding: const EdgeInsets.all(8),
  itemCount: entries.length,
  itemBuilder: (BuildContext context, int index) {
    return Container(
      height: 50,
      color: Colors.amber[colorCodes[index]],
      child: Center(child: Text('Entry ${entries[index]}')),
    );
  },
  separatorBuilder: (BuildContext context, int index) => const Divider(),
);

void main() {
  final TestWidgetsFlutterBinding binding = TestWidgetsFlutterBinding.ensureInitialized();


  testWidgets('some test', (WidgetTester tester) async {
    await binding.setSurfaceSize(Size(640, 1136));
    print(binding.createViewConfiguration());
 ...

void main() {
  final TestWidgetsFlutterBinding binding = TestWidgetsFlutterBinding.ensureInitialized();


  testWidgets('some test', (WidgetTester tester) async {
    await binding.setSurfaceSize(Size(640, 1136));
    print(binding.createViewConfiguration());
 ...

void main() {
  final TestWidgetsFlutterBinding binding = TestWidgetsFlutterBinding.ensureInitialized();


  testWidgets('some test', (WidgetTester tester) async {
    await binding.setSurfaceSize(Size(640, 1136));
    print(binding.createViewConfiguration());
 ...