examples/api/lib/material/input_decorator/input_decoration.floating_label_style_error.0.dart

// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'package:flutter/material.dart';

/// Flutter code sample for [InputDecorator].

void main() => runApp(const FloatingLabelStyleErrorExampleApp());

class FloatingLabelStyleErrorExampleApp extends StatelessWidget {
  const FloatingLabelStyleErrorExampleApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: ThemeData(useMaterial3: true),
      home: Scaffold(
        appBar: AppBar(title: const Text('InputDecorator Sample')),
        body: const Center(
          child: InputDecoratorExample(),
        ),
      ),
    );
  }
}

class InputDecoratorExample extends StatelessWidget {
  const InputDecoratorExample({super.key});

  @override
  Widget build(BuildContext context) {
    return TextFormField(
      decoration: InputDecoration(
        border: const OutlineInputBorder(),
        labelText: 'Name',
        // The MaterialStateProperty's value is a text style that is orange
        // by default, but the theme's error color if the input decorator
        // is in its error state.
        floatingLabelStyle: MaterialStateTextStyle.resolveWith(
          (Set<MaterialState> states) {
            final Color color =
                states.contains(MaterialState.error) ? Theme.of(context).colorScheme.error : Colors.orange;
            return TextStyle(color: color, letterSpacing: 1.3);
          },
        ),
      ),
      validator: (String? value) {
        if (value == null || value == '') {
          return 'Enter name';
        }
        return null;
      },
      autovalidateMode: AutovalidateMode.always,
    );
  }
}