RockInRio.dart

import 'package:flutter/material.dart';

void main() {
  runApp(const RockInRio());
}

class RockInRio extends StatelessWidget {
  const RockInRio ({ Key? key}) : super (key:key);
  
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Rock In Rio App',
      debugShowCheckedModeBanner: false,
      theme: ThemeData(primarySwatch: Colors.indigo),
      home: const HomePage(),
    );
  }
}

class HomePage extends StatefulWidget {
  const HomePage({Key? key}) : super(key: key);
  
  @override
  State<HomePage> createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {
  final List<Atracao> _listaFavoritos = [];
  
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Atrações'),
      ),
      body: ListView.builder(
        itemCount: listaAtracoes.length,
        itemBuilder: (context, index) {
          final isFavorito = _listaFavoritos.contains(listaAtracoes[index]);
           return ListTile(
             onTap: () {
               Navigator.push(
                context,
                 MaterialPageRoute(
                  builder: (context) => 
                   AtracaoPage(
                    atracao: listaAtracoes[index]
                   )
                 ));
             },
            title: Text(listaAtracoes[index].nome),
            subtitle: Wrap(
              spacing: 8,
              runSpacing: 4,
              children: listaAtracoes[index]
                .tags
                .map((tag) =>
                    Chip(label: Text('$tag'))
                    )
                .toList(),
            ),
             leading: CircleAvatar(
              child: Text('${listaAtracoes[index].dia}')
             ),
             trailing: IconButton(
              onPressed: () {
                setState(() {
                  if (isFavorito) {
                    _listaFavoritos.remove(listaAtracoes[index]);
                  }
                  else {
                    _listaFavoritos.add(listaAtracoes[index]);
                  }
                  
                });
              },
               icon: isFavorito ?
               const Icon(Icons.favorite, color: Colors.red)
               : const Icon(Icons.favorite_border),
               
              ),
           );
        },
      )
    );
  }
}

class Atracao {
  final String nome;
  final int dia;
  final List<String> tags;
  
  const Atracao(this.nome, this.dia, this.tags);
}

class AtracaoPage extends StatelessWidget {
  final Atracao atracao;
  const AtracaoPage({Key? key, required this.atracao}) : super(key: key);
  
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(atracao.nome),
      ),
      body: Padding(
        padding: const EdgeInsets.all(16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            for (var tag in atracao.tags)
            Chip(label: Text('#$tag')),
            const SizedBox(height: 16),
            ElevatedButton(
              onPressed: () {
                Navigator.pop(context);
              },
              child: const Text('Voltar'),
            )
          ],
        ),
      ),
    );
  }
}


const listaAtracoes = [
  Atracao("Iron Maiden", 2, ["Espetaculo", "Fas", "NovoAlbum"]),
  Atracao("Alok", 3, ["Influente", "Top", "Show"]),
  Atracao("Justin Bieber", 4, ["TopCharts", "Hits", "PríncipeDoPOP"]),
  Atracao("Guns N’ Roses", 8, ["Sucesso", "Espetáculo", "Fas"]),
  Atracao("Capital Inicial", 9, ["2019", "Novo Álbum", "Fas"]),
  Atracao("Green Day", 9, ["Sucesso", "Reconhecimento", "Show"]),
  Atracao("Cold Play", 10, ["NovoAlbum", "Sucesso", "2011"]),
  Atracao("Ivete Sangalo", 10, ["Unica", "Carreiras", "Fas"]),
  Atracao("Racionais", 3, ["Hits", "Prêmios", "Respeito"]),
  Atracao("Gloria Groove", 8, ["Streams", "Representatividade", "Sucesso"]),
  Atracao("Avril Lavigne", 9, ["Estreia", "Sucesso", "Lançamento"]),
  Atracao("Ludmilla", 10, ["Representativade", "Sucesso", "Parcerias"]),
];