mvc_pattern 0.0.8

To develop apps using a framework following the MVC design pattern separating the app's 'interface' from its 'business logic' and from its data source if any.

example/lib/main.dart

/// Note: This license has also been called the "Simplified BSD License" and the "FreeBSD License".
/// See also the 2-clause BSD License.
///
/// Copyright 2018 www.andrioussolutions.com
///
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/// are permitted provided that the following conditions are met:
///
/// 1. Redistributions of source code must retain the above copyright notice,
/// this list of conditions and the following disclaimer.
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/// 2. Redistributions in binary form must reproduce the above copyright notice,
/// this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
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import 'package:flutter/material.dart';

/// Uncomment at 'get packages' to try out this example.
//import 'package:english_words/english_words.dart';

import 'package:mvc_pattern/mvc_pattern.dart';

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

class MyApp extends AppMVC {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Startup Name Generator',
      theme: ThemeData(
        primaryColor: Colors.white,
      ),
      home: RandomWords(),
    );
  }
}

class RandomWords extends StatefulWidgetMVC {
  RandomWords() : super(RandomWordsState(Con()));
}

class RandomWordsState extends StateMVC {
  RandomWordsState(Con con) : super(con);

  final TextStyle _biggerFont = const TextStyle(fontSize: 18.0);

  @override

  /// the View
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Startup Name Generator'),
        actions: <Widget>[
          IconButton(
              icon: const Icon(Icons.list),
              onPressed: () {
                pushSaved(context);
              }),
        ],
      ),
      body: _buildSuggestions(),
    );
  }

  Widget _buildSuggestions() {
    return ListView.builder(
      padding: const EdgeInsets.all(16.0),
      // The itemBuilder callback is called once per suggested word pairing,
      // and places each suggestion into a ListTile row.
      // For even rows, the function adds a ListTile row for the word pairing.
      // For odd rows, the function adds a Divider widget to visually
      // separate the entries. Note that the divider may be difficult
      // to see on smaller devices.
      itemBuilder: (context, i) {
        // Add a one-pixel-high divider widget before each row in theListView.
        if (i.isOdd) return Divider();

        // The syntax "i ~/ 2" divides i by 2 and returns an integer result.
        // For example: 1, 2, 3, 4, 5 becomes 0, 1, 1, 2, 2.
        // This calculates the actual number of word pairings in the ListView,
        // minus the divider widgets.
        final index = i ~/ 2;
        // If you've reached the end of the available word pairings...
        if (index >= Con.length) {
          // ...then generate 10 more and add them to the suggestions list.
          Con.addAll(10);
        }
        return buildRow(index);
      },
    );
  }

  void pushSaved(BuildContext context) {
    Navigator.of(context).push(
      MaterialPageRoute<void>(
        builder: (BuildContext context) {
          final Iterable<ListTile> tiles = this.tiles;

          final List<Widget> divided = ListTile.divideTiles(
            context: context,
            tiles: tiles,
          ).toList();

          return Scaffold(
            appBar: AppBar(
              title: const Text('Saved Suggestions'),
            ),
            body: ListView(children: divided),
          );
        },
      ),
    );
  }

  Widget buildRow(int index) {
    if (index == null && index < 0) index = 0;

    String something = Con.something(index);

    final alreadySaved = Con.contains(something);

    return ListTile(
      title: Text(
        something,
        style: _biggerFont,
      ),
      trailing: Icon(
        alreadySaved ? Icons.favorite : Icons.favorite_border,
        color: alreadySaved ? Colors.red : null,
      ),
      onTap: () {
        setState(() {
          Con.somethingHappens(something);
        });
      },
    );
  }

  Iterable<ListTile> get tiles => Con.mapHappens(
        (String something) {
          return ListTile(
            title: Text(
              something,
              style: _biggerFont,
            ),
          );
        },
      );
}


class Con extends ControllerMVC {
  static int get length => Model.length;

  static void addAll(int count) => Model.addAll(count);

  static String something(int index) => Model.wordPair(index);

  static bool contains(String something) => Model.contains(something);

  static void somethingHappens(String something) => Model.save(something);

  static Iterable<ListTile> mapHappens<ListTile>(Function f) => Model.saved(f);
}


class Model {
  static final List<String> _suggestions = [];
  static int get length => _suggestions.length;

  static String wordPair(int index) {
    if (index == null || index < 0) index = 0;
    return _suggestions[index];
  }

  static bool contains(String pair) {
    if (pair == null || pair.isEmpty) return false;
    return _saved.contains(pair);
  }

  static final Set<String> _saved = Set();

  static void save(String pair) {
    if (pair == null || pair.isEmpty) return;
    final alreadySaved = contains(pair);
    if (alreadySaved) {
      _saved.remove(pair);
    } else {
      _saved.add(pair);
    }
  }

  static Iterable<ListTile> saved<ListTile>(Function f) => _saved.map(f);

  static Iterable<String> wordPairs([int count = 10]) => makeWordPairs(count);

  static void addAll(int count) {
    _suggestions.addAll(wordPairs(count));
  }
}

Iterable<String> makeWordPairs(int count) {
  /// Uncomment to try this example.
//  return generateWordPairs().take(count).map((pair){return pair.asPascalCase;});
}