monke

lib/main.dart

@@ -20,6 +20,49 @@ class MyApp extends StatelessWidget {
   }
 }
 
+abstract class ListStrategy<T> {
+  List<T> compose(List<T> items);
+}
+
+class Monkey {
+  Monkey({required this.name, required this.power});
+  final String name;
+  final int power;
+
+  @override
+  String toString() => '$name - Power: $power';
+}
+
+class GreatestMonkeyStrategy implements ListStrategy<Monkey> {
+  @override
+  List<Monkey> compose(List<Monkey> items) {
+    return [
+      items.fold<Monkey>(
+          Monkey(name: '', power: 0), (aMonkey, bMonkey) => aMonkey.power > bMonkey.power ? aMonkey : bMonkey)
+    ];
+  }
+}
+
+class WeakMonkeysStrategy implements ListStrategy<Monkey> {
+  @override
+  List<Monkey> compose(List<Monkey> items) {
+    return items
+        .where(
+          (element) => element.power <= 200,
+        )
+        .toList();
+  }
+}
+
+List<Monkey> monkeys = [
+  Monkey(name: 'Mortimer', power: 25),
+  Monkey(name: 'ApeMan', power: 354),
+  Monkey(name: 'Spider', power: 65),
+  Monkey(name: 'DK', power: 500),
+  Monkey(name: 'Tim', power: 120),
+  Monkey(name: 'Kong', power: 25400),
+];
+
 class MyHomePage extends StatefulWidget {
   const MyHomePage({super.key});
 
@@ -28,6 +71,16 @@ class MyHomePage extends StatefulWidget {
 }
 
 class _MyHomePageState extends State<MyHomePage> {
+  ListStrategy listStrat = WeakMonkeysStrategy();
+
+  void swapStrategies() {
+    if (listStrat.runtimeType == WeakMonkeysStrategy) {
+      setState(() => listStrat = GreatestMonkeyStrategy());
+      return;
+    }
+    setState(() => listStrat = WeakMonkeysStrategy());
+  }
+
   @override
   Widget build(BuildContext context) {
     return Scaffold(
@@ -39,13 +92,22 @@ class _MyHomePageState extends State<MyHomePage> {
         child: Column(
           mainAxisAlignment: MainAxisAlignment.center,
           children: <Widget>[
-            const Text(
-              'You have pushed the button this many times:',
-            ),
-            Text(
-              'some text',
-              style: Theme.of(context).textTheme.headlineMedium,
-            ),
+            const Text('All monkeys:'),
+            ...monkeys
+                .map(
+                  (e) => Text(e.toString()),
+                )
+                .toList(),
+            const SizedBox(height: 50),
+            Text(listStrat.runtimeType.toString()),
+            ...listStrat
+                .compose(monkeys)
+                .map(
+                  (e) => Text(e.toString()),
+                )
+                .toList(),
+            const SizedBox(height: 100),
+            ElevatedButton(onPressed: () => swapStrategies(), child: const Text('Change Strats')),
           ],
         ),
       ),