mirrored_repositories/flutter-ejemplos/startup_namer
import 'package:flutter/material.dart';
import 'package:english_words/english_words.dart';

void main() => runApp(MyApp());

// no guarda su estadpo, es inmutable
class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,// ocualta el label 'debug'
      title: 'Welcome to Flutter',
      theme: ThemeData(primaryColor: Colors.green),
      home: RandomWords(),
    );
  }
}

// guarda su estado
class RandomWords extends StatefulWidget {
  @override
  State<StatefulWidget> createState() {
    return RandomWordsState();
  }
}

class RandomWordsState extends State<RandomWords> {
  final _suggestions = <WordPair>[];
  final _saved = Set<WordPair>();
  final _biggerFont = const TextStyle(fontSize: 18);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Welcome to Flutter'),
        actions: <Widget>[
          IconButton(icon: Icon(Icons.list), onPressed: _pushSaved)
        ],
      ),
      body: _buildSuggestions(),
    );
  }

  Widget _buildSuggestions() {
    return ListView.builder(
      padding: const EdgeInsets.all(16.0),
      itemBuilder: (context, i) {
        if (i.isOdd) return Divider();
        if (i >= _suggestions.length) {
          _suggestions.addAll(generateWordPairs().take(10));
        }
        final index = i ~/ 2;
        return _buildRow(_suggestions[index]);
      },
    );
  }

  void _pushSaved() {
    Navigator.of(context).push(MaterialPageRoute(builder: (context) {
      final tiles = _saved.map((pair) {
        return ListTile(
          title: Text(
            pair.asPascalCase,
            style: _biggerFont,
          ),
        );
      });
      final divided =
          ListTile.divideTiles(context: context, tiles: tiles).toList();
      return Scaffold(
        appBar: AppBar(
          title: Text('Saved Suggestions'),
        ),
        body: ListView(children: divided),
      );
    }));
  }

  Widget _buildRow(WordPair pair) {
    final alreadySaved = _saved.contains(pair);
    return ListTile(
      title: Text(pair.asPascalCase, style: _biggerFont),
      trailing: Icon(
        alreadySaved ? Icons.favorite : Icons.favorite_border,
        color: alreadySaved ? Colors.red : null,
      ),
      onTap: () {
        setState(() {
          if (alreadySaved) {
            _saved.remove(pair);
          } else {
            _saved.add(pair);
          }
        });
      },
    );
  }
}
