Heavily documented flutter starter app boilerplate.

flutter_starter.dart

import 'package:flutter/material.dart';
import 'package:english_words/english_words.dart';

// Arrow functions for one line functions
void main() => runApp(MyApp());

// Makes App itself widget -> Nearly everything is widget(alignment, padding & layout)
class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Startup Name Generator',
      // Change theme by using ThemeData class
      theme: ThemeData(
        primaryColor: Colors.blueGrey,
      ),
      // Widget Tree for Home screen(Can be quite complex)
      home: RandomWords(),
    );
  }
}

/**
 * Stateless Widgets -> Immutable
 * Stateful widgets -> Mantain state through lifetime
 * Implementtaion stateful widget = stateful widget class + instance of class
 */

// Stateful widget RandomWords, which created State class <RandomWordState>(Generic State class)
class RandomWordsState extends State<RandomWords> {
  /* Prefixing identifier with  _ enhances privacy */

  // Suggestions list to save suggested word pairings
  final _suggestions = <WordPair>[];
  // Variable to make font bigger
  final _biggerFont = const TextStyle(fontSize: 18.0);
  // Store word favourite word pairings(Set prefered over List, because no duplicates are allowed)
  final Set<WordPair> _saved = Set<WordPair>();

  // Build method to generate words pairs(Removing from MyApp class)
  @override
  Widget build(BuildContext context) {
    // Implement the basic material design visual layout
    return Scaffold(
      appBar: AppBar(
        title: Text('Startup Name Generator'),

        /*
         Add new page(route)
         Navigate between home route & new route
         Navigator manages a stack containing the app's routes
         Use Push/Pop To change dislays
         */

        actions: <Widget>[
          // When clicked, a new route with the saved favorites is pushed to the navigator
          IconButton(icon: Icon(Icons.list), onPressed: _pushSaved),
        ],
      ),
      body: _buildSuggestions(),
    );
  }

  // Build ListView to display word pairings
  Widget _buildSuggestions() {
    return ListView.builder(
      // callback once per suggested word pairing & place suggestion in ListTile row
      itemBuilder: (context, i) {
        // Add pixel divider
        if (i.isOdd) return Divider();

        final index = i ~/ 2;
        if (index >= _suggestions.length) {
          _suggestions.addAll(generateWordPairs().take(10));
        }
        // Display each new pair in ListTile
        return _buildRow(_suggestions[index]);
      },
    );
  }

  // Display each new pair in ListTile
  Widget _buildRow(WordPair pair) {
    // Variable to ensure that a word pairing has not already been added to favorites
    final bool alreadySaved = _saved.contains(pair);

    return ListTile(
      title: Text(
        pair.asPascalCase,
        style: _biggerFont,
      ),
      // Heart shaped Icon
      trailing: Icon(
        alreadySaved ? Icons.favorite : Icons.favorite_border,
        color: alreadySaved ? Colors.red : null,
      ),
      // Event listener to change the state of the icon & change the state
      onTap: () {
        setState(() {
          if (alreadySaved) {
            _saved.remove(pair);
          } else {
            _saved.add(pair);
          }
        });
      },
    );
  }

  /*
  Build a route and push it to the Navigator's stack. 
  Change the screen to display a new route
  */
  void _pushSaved() {
    // Push the route to the navigators stack
    Navigator.of(context).push(
      MaterialPageRoute<void>(
        builder: (BuildContext context) {
          // Generate the ListTile rows
          final Iterable<ListTile> tiles = _saved.map(
            (WordPair pair) {
              return ListTile(
                title: Text(
                  pair.asPascalCase,
                  style: _biggerFont,
                ),
              );
            },
          );
          // divideTiles: Add Horizontal spacing between each ListTile
          // divided: Holds final rows
          // toList: Convert to a list
          final List<Widget> divided = ListTile.divideTiles(
            context: context,
            tiles: tiles,
          ).toList();

          // Return a Scafforl with:
          // AppBar for new Rout
          // Body of new route -> ListView with ListTiles rows(each row separated by divider)
          return Scaffold(
            appBar: AppBar(
              title: Text('Saved Suggestions'),
            ),
            body: ListView(children: divided),
          );
        },
      ),
    );
  }
}

// Stateful RandomWords widget to create State class
class RandomWords extends StatefulWidget {
  @override
  RandomWordsState createState() => RandomWordsState();
}