Add Decorator Pattern

Author: bhagat-hrishi

Design patterns/Singleton/Singleton.java …erns/Creational/Singleton/Singleton.javaDesign patterns/Singleton/Singleton.java renamed to Design patterns/Creational/Singleton/Singleton.java Design patterns/Singleton/Singleton.java renamed to Design patterns/Creational/Singleton/Singleton.java

@@ -0,0 +1,5 @@
+class Circle implements Shape {
+   public void draw (){
+       System.out.println("Shape : Circle");
+   }
+}

Design patterns/Structural Pattern/Decorator/Circle.java

@@ -2,23 +2,18 @@
     1)Object at central is called Component and one wrapping component is call Decorator
     and one wrapping decorator is called Decorator
     2)Attach additional responsibilities to an object dynamically.
+    Decorators provide a flexible alternative to subclassing for extending functionality
 */
 
-abstract class ok 
-{
-     abstract void m1();
-     void m2()
-     {
-         System.out.println("This is data from m2");
-     }
-}
-class DecoratorDemo extends ok {
-    void m1()
-    {
-        System.out.println("This is frmo m1");
-    }
+class DecoratorDemo{
     public static void main(String[] args) {
-        DecoratorDemo obj =  new DecoratorDemo();
-        obj.m2();
+        Shape circle = new Circle();
+        System.out.println("\nCircle with normal boredr");
+        circle.draw();
+
+        circle = new RedShapeDecorator(circle);
+        System.out.println("\nCircle with Red boredr");
+        circle.draw();
+        
     }
 }

Design patterns/Structural Pattern/Decorator/DecoratorDemo.java

@@ -0,0 +1,13 @@
+class RedShapeDecorator extends ShapeDecorator {
+    public RedShapeDecorator(Shape decoratedShape) {
+        super(decoratedShape);
+    }
+
+    private void setRedBorder(Shape decoratedShape){
+        System.out.println("Border Color : Red");
+    }
+    public void draw(){
+        decoratedShape.draw();
+        setRedBorder(decoratedShape);
+    }
+}

Design patterns/Structural Pattern/Decorator/RedShapeDecorator.java

@@ -0,0 +1,3 @@
+interface Shape {
+    void draw();
+}

Design patterns/Structural Pattern/Decorator/Shape.java

@@ -0,0 +1,10 @@
+public abstract class ShapeDecorator  implements Shape {
+     protected Shape decoratedShape ;
+    public ShapeDecorator(Shape decoratedShape){
+        this.decoratedShape =  decoratedShape;
+    }
+
+    public void draw(){
+        this.decoratedShape.draw();
+    }
+}

Design patterns/Structural Pattern/Decorator/ShapeDecorator.java

@@ -0,0 +1,5 @@
+class Square implements Shape {
+    public void draw(){
+        System.out.println("Shape : Square");
+    }
+}