beauty builders

lib/main.dart

@@ -20,47 +20,66 @@ 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)
-    ];
+///
+/// Shape Builder
+///
+abstract class ShapeBuilder {
+  Widget build(Size size, Widget child) {
+    return Container(
+      height: size.height,
+      width: size.width,
+      decoration: BoxDecoration(shape: boxShape, color: shapeColor),
+      child: Center(child: child),
+    );
   }
+
+  BoxShape get boxShape;
+  Color get shapeColor;
 }
 
-class WeakMonkeysStrategy implements ListStrategy<Monkey> {
+class RedSquareBuilder extends ShapeBuilder {
   @override
-  List<Monkey> compose(List<Monkey> items) {
-    return items
-        .where(
-          (element) => element.power <= 200,
-        )
-        .toList();
-  }
+  BoxShape get boxShape => BoxShape.rectangle;
+
+  @override
+  Color get shapeColor => Colors.red;
 }
 
-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 BlueCircleBuilder extends ShapeBuilder {
+  @override
+  BoxShape get boxShape => BoxShape.circle;
+
+  @override
+  Color get shapeColor => Colors.blue;
+}
+
+///
+/// Message Builder (Writer seemed appropriate)
+///
+abstract class MessageWriter {
+  Text write(String text);
+}
+
+class HotMessageWriter extends MessageWriter {
+  @override
+  Text write(String text) => Text(text, style: const TextStyle(fontWeight: FontWeight.bold, fontSize: 18));
+}
+
+class ColdMessageWriter extends MessageWriter {
+  @override
+  Text write(String text) => Text(text, style: const TextStyle(color: Colors.white, fontSize: 14));
+}
+
+final List<ShapeBuilder> builders = [
+  RedSquareBuilder(),
+  BlueCircleBuilder(),
+  RedSquareBuilder(),
+];
+
+final List<MessageWriter> writers = [
+  ColdMessageWriter(),
+  HotMessageWriter(),
+  HotMessageWriter(),
 ];
 
 class MyHomePage extends StatefulWidget {
@@ -71,43 +90,25 @@ 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(
       appBar: AppBar(
         backgroundColor: Theme.of(context).colorScheme.inversePrimary,
-        title: const Text('Abstract Factory'),
+        title: const Text('Builders'),
       ),
       body: Center(
         child: Column(
           mainAxisAlignment: MainAxisAlignment.center,
           children: <Widget>[
-            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')),
+            const Text('Builders!!'),
+            ...List.generate(
+              3,
+              (index) => builders[index].build(
+                Size(80.0 * (index + 1), 90.0 * (index + 1)),
+                writers[index].write('build ${index + 1}'),
+              ),
+            ),
           ],
         ),
       ),