Impl flyweight conceptual pattern.

Author: ilopX

patterns/flyweight/conceptual/main.dart

@@ -0,0 +1,22 @@
+// ignore_for_file: non_constant_identifier_names
+
+import 'pattern/flyweight_factory.dart';
+
+void main() {
+  final factory = FlyweightFactory();
+
+  final one = factory.create('one');
+  one.draw();
+
+  final ONE = factory.create('ONE');
+  ONE.draw();
+
+  final OnE = factory.create('OnE');
+  OnE.draw();
+
+  final two = factory.create('two');
+  two.draw();
+
+  final Two = factory.create('Two');
+  Two.draw();
+}

patterns/flyweight/conceptual/params/share_params.dart

@@ -0,0 +1,7 @@
+class ShareParams {
+  final int param1;
+  final String param2;
+  final double param3;
+
+  ShareParams(this.param1, this.param2, this.param3);
+}

patterns/flyweight/conceptual/pattern/flyweight.dart

@@ -0,0 +1,17 @@
+import '../params/share_params.dart';
+
+class Flyweight {
+  final String localParam;
+  final ShareParams shareParams;
+
+  Flyweight(this.localParam, this.shareParams);
+
+  void draw() {
+    print('Flyweight(');
+    print('\tlocalParam: "$localParam", shareParam: ('
+        '${shareParams.param1}, '
+        '"${shareParams.param2}", '
+        '${shareParams.param3})');
+    print(')');
+  }
+}

patterns/flyweight/conceptual/pattern/flyweight_factory.dart

@@ -0,0 +1,20 @@
+import 'flyweight.dart';
+import '../params/share_params.dart';
+import '../utils/fake_value.dart';
+
+class FlyweightFactory {
+  Flyweight create(String localParam) {
+    final shareParams = _shares.putIfAbsent(
+      localParam.toLowerCase(),
+      () => ShareParams(
+        fakeInt,
+        fakeString,
+        fakeDouble,
+      ),
+    );
+
+    return Flyweight(localParam, shareParams);
+  }
+
+  final _shares = <String, ShareParams>{};
+}

patterns/flyweight/conceptual/utils/fake_value.dart

@@ -0,0 +1,12 @@
+import 'dart:math';
+
+String str = 'abcdef';
+get fakeString {
+  final char = str[Random().nextInt(str.length - 1)];
+  str = str.replaceFirst(char, '');
+  return char;
+}
+
+get fakeInt => Random().nextInt(100);
+
+get fakeDouble => Random().nextInt(100) / 100;