monke

lib/main.dart

@@ -20,32 +20,49 @@ class MyApp extends StatelessWidget {
   }
 }
 
-abstract class ShapeFactory {
-  Widget build(Size size, Color color);
+abstract class ListStrategy<T> {
+  List<T> compose(List<T> items);
 }
 
-class SquareFactory extends ShapeFactory {
+class Monkey {
+  Monkey({required this.name, required this.power});
+  final String name;
+  final int power;
+
   @override
-  Widget build(Size size, Color color) {
-    return SizedBox.fromSize(
-      size: size,
-      child: Container(color: color),
-    );
+  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 CircleFactory extends ShapeFactory {
+class WeakMonkeysStrategy implements ListStrategy<Monkey> {
   @override
-  Widget build(Size size, Color color) {
-    return SizedBox.fromSize(
-      size: size,
-      child: Container(
-        decoration: BoxDecoration(shape: BoxShape.circle, color: color),
-      ),
-    );
+  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});
 
@@ -54,16 +71,14 @@ class MyHomePage extends StatefulWidget {
 }
 
 class _MyHomePageState extends State<MyHomePage> {
-  final List<ShapeFactory> shapeFactories = [CircleFactory(), SquareFactory()];
-  int factoryIndex = 0;
-  ShapeFactory get factory => shapeFactories[factoryIndex];
+  ListStrategy listStrat = WeakMonkeysStrategy();
 
-  void swapFactories() {
-    if (factoryIndex == 0) {
-      setState(() => factoryIndex = 1);
+  void swapStrategies() {
+    if (listStrat.runtimeType == WeakMonkeysStrategy) {
+      setState(() => listStrat = GreatestMonkeyStrategy());
       return;
     }
-    setState(() => factoryIndex = 0);
+    setState(() => listStrat = WeakMonkeysStrategy());
   }
 
   @override
@@ -77,18 +92,22 @@ class _MyHomePageState extends State<MyHomePage> {
         child: Column(
           mainAxisAlignment: MainAxisAlignment.center,
           children: <Widget>[
-            const Text('Abstract Factories!!'),
-            Text('Using ${shapeFactories[factoryIndex].runtimeType.toString()}'),
-            ...List.generate(
-                3,
-                (index) => factory.build(
-                      Size(20.0 * (index + 1), 30.0 * (index + 1)),
-                      [Colors.red, Colors.green, Colors.blue][index],
-                    )),
-            ElevatedButton(
-              onPressed: () => swapFactories(),
-              child: const Text('Swap Factories'),
-            ),
+            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')),
           ],
         ),
       ),