117 lines
2.8 KiB
Dart
117 lines
2.8 KiB
Dart
import 'package:flutter/material.dart';
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void main() {
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runApp(const MyApp());
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}
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class MyApp extends StatelessWidget {
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const MyApp({super.key});
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@override
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Widget build(BuildContext context) {
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return MaterialApp(
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title: 'Flutter Demo',
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theme: ThemeData(
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colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
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useMaterial3: true,
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),
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home: const MyHomePage(),
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);
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}
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}
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abstract class ListStrategy<T> {
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List<T> compose(List<T> items);
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}
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class Monkey {
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Monkey({required this.name, required this.power});
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final String name;
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final int power;
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@override
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String toString() => '$name - Power: $power';
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}
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class GreatestMonkeyStrategy implements ListStrategy<Monkey> {
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@override
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List<Monkey> compose(List<Monkey> items) {
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return [
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items.fold<Monkey>(
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Monkey(name: '', power: 0), (aMonkey, bMonkey) => aMonkey.power > bMonkey.power ? aMonkey : bMonkey)
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];
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}
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}
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class WeakMonkeysStrategy implements ListStrategy<Monkey> {
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@override
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List<Monkey> compose(List<Monkey> items) {
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return items
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.where(
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(element) => element.power <= 200,
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)
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.toList();
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}
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}
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List<Monkey> monkeys = [
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Monkey(name: 'Mortimer', power: 25),
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Monkey(name: 'ApeMan', power: 354),
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Monkey(name: 'Spider', power: 65),
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Monkey(name: 'DK', power: 500),
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Monkey(name: 'Tim', power: 120),
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Monkey(name: 'Kong', power: 25400),
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];
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class MyHomePage extends StatefulWidget {
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const MyHomePage({super.key});
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@override
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State<MyHomePage> createState() => _MyHomePageState();
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}
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class _MyHomePageState extends State<MyHomePage> {
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ListStrategy listStrat = WeakMonkeysStrategy();
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void swapStrategies() {
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if (listStrat.runtimeType == WeakMonkeysStrategy) {
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setState(() => listStrat = GreatestMonkeyStrategy());
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return;
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}
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setState(() => listStrat = WeakMonkeysStrategy());
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}
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@override
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Widget build(BuildContext context) {
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return Scaffold(
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appBar: AppBar(
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backgroundColor: Theme.of(context).colorScheme.inversePrimary,
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title: const Text('Abstract Factory'),
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),
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body: Center(
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child: Column(
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mainAxisAlignment: MainAxisAlignment.center,
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children: <Widget>[
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const Text('All monkeys:'),
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...monkeys
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.map(
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(e) => Text(e.toString()),
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)
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.toList(),
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const SizedBox(height: 50),
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Text(listStrat.runtimeType.toString()),
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...listStrat
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.compose(monkeys)
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.map(
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(e) => Text(e.toString()),
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)
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.toList(),
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const SizedBox(height: 100),
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ElevatedButton(onPressed: () => swapStrategies(), child: const Text('Change Strats')),
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],
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),
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),
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);
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}
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}
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