flutter_flutter/examples/api/lib/widgets/autocomplete/raw_autocomplete.2.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 [RawAutocomplete].

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

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

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(title: const Text('RawAutocomplete Form')),
        body: const Center(child: AutocompleteFormExample()),
      ),
    );
  }
}

class AutocompleteFormExample extends StatefulWidget {
  const AutocompleteFormExample({super.key});

  @override
  AutocompleteFormExampleState createState() => AutocompleteFormExampleState();
}

class AutocompleteFormExampleState extends State<AutocompleteFormExample> {
  final GlobalKey<FormState> _formKey = GlobalKey<FormState>();
  final TextEditingController _textEditingController = TextEditingController();
  String? _dropdownValue;
  String? _autocompleteSelection;

  static const List<String> _options = <String>['aardvark', 'bobcat', 'chameleon'];

  @override
  Widget build(BuildContext context) {
    return Form(
      key: _formKey,
      child: Column(
        children: <Widget>[
          DropdownButtonFormField<String>(
            initialValue: _dropdownValue,
            icon: const Icon(Icons.arrow_downward),
            hint: const Text('This is a regular DropdownButtonFormField'),
            elevation: 16,
            style: const TextStyle(color: Colors.deepPurple),
            onChanged: (String? newValue) {
              setState(() {
                _dropdownValue = newValue;
              });
            },
            items: <String>['One', 'Two', 'Free', 'Four'].map<DropdownMenuItem<String>>((
              String value,
            ) {
              return DropdownMenuItem<String>(value: value, child: Text(value));
            }).toList(),
            validator: (String? value) {
              if (value == null) {
                return 'Must make a selection.';
              }
              return null;
            },
          ),
          TextFormField(
            controller: _textEditingController,
            decoration: const InputDecoration(hintText: 'This is a regular TextFormField'),
            validator: (String? value) {
              if (value == null || value.isEmpty) {
                return "Can't be empty.";
              }
              return null;
            },
          ),
          RawAutocomplete<String>(
            optionsBuilder: (TextEditingValue textEditingValue) {
              return _options.where((String option) {
                return option.contains(textEditingValue.text.toLowerCase());
              });
            },
            onSelected: (String selection) {
              setState(() {
                _autocompleteSelection = selection;
              });
            },
            fieldViewBuilder:
                (
                  BuildContext context,
                  TextEditingController textEditingController,
                  FocusNode focusNode,
                  VoidCallback onFieldSubmitted,
                ) {
                  return TextFormField(
                    controller: textEditingController,
                    decoration: const InputDecoration(hintText: 'This is a RawAutocomplete!'),
                    focusNode: focusNode,
                    onFieldSubmitted: (String value) {
                      onFieldSubmitted();
                    },
                    validator: (String? value) {
                      if (!_options.contains(value)) {
                        return 'Nothing selected.';
                      }
                      return null;
                    },
                  );
                },
            optionsViewBuilder:
                (
                  BuildContext context,
                  AutocompleteOnSelected<String> onSelected,
                  Iterable<String> options,
                ) {
                  return Align(
                    alignment: Alignment.topLeft,
                    child: Material(
                      elevation: 4.0,
                      child: SizedBox(
                        height: 200.0,
                        child: ListView.builder(
                          padding: const EdgeInsets.all(8.0),
                          itemCount: options.length,
                          itemBuilder: (BuildContext context, int index) {
                            final String option = options.elementAt(index);
                            return GestureDetector(
                              onTap: () {
                                onSelected(option);
                              },
                              child: ListTile(title: Text(option)),
                            );
                          },
                        ),
                      ),
                    ),
                  );
                },
          ),
          ElevatedButton(
            onPressed: () {
              FocusScope.of(context).unfocus();
              if (!_formKey.currentState!.validate()) {
                return;
              }
              showDialog<void>(
                context: context,
                builder: (BuildContext context) {
                  return AlertDialog(
                    title: const Text('Successfully submitted'),
                    content: SingleChildScrollView(
                      child: ListBody(
                        children: <Widget>[
                          Text('DropdownButtonFormField: "$_dropdownValue"'),
                          Text('TextFormField: "${_textEditingController.text}"'),
                          Text('RawAutocomplete: "$_autocompleteSelection"'),
                        ],
                      ),
                    ),
                    actions: <Widget>[
                      TextButton(
                        child: const Text('Ok'),
                        onPressed: () {
                          Navigator.of(context).pop();
                        },
                      ),
                    ],
                  );
                },
              );
            },
            child: const Text('Submit'),
          ),
        ],
      ),
    );
  }
}