Some modifications

src/main/java/shape/AbstractShape.java

@@ -3,23 +3,28 @@ package shape;
 import javafx.geometry.Point2D;
 import javafx.scene.canvas.GraphicsContext;
 
+import java.util.ArrayList;
 import java.util.List;
 
 public abstract class AbstractShape implements Shape {
     private List<Point2D> points;
+
+    public AbstractShape(){
+        this.points = new ArrayList<>();
+    }
     @Override
     public int pointsCount() {
-        return points.size();
+        return this.points.size();
     }
 
     @Override
     public Point2D point(int index) {
-        return points.get(index);
+        return this.points.get(index);
     }
 
     @Override
     abstract public void draw(GraphicsContext context) ;
     public void addPoints(List<Point2D> points) {
-         points.addAll(points);
+         this.points.addAll(points);
     }
 }

src/main/java/shape/App.java

@@ -10,6 +10,8 @@ import javafx.scene.paint.Color;
 import javafx.scene.paint.Paint;
 import javafx.stage.Stage;
 
+import java.util.ArrayList;
+import java.util.List;
 
 
 public class App extends Application {
@@ -26,7 +28,13 @@ public class App extends Application {
         ShapeContainer shapeContainer = new ShapeContainer();
         graphicsContext.setFill(Color.AQUAMARINE);
         graphicsContext.fillOval(10,10,10,10);
-        shapeContainer.addShape(new Rectangle(Color.BLUE,new Point2D(10,10), new Point2D(40,40)));
+        shapeContainer.addShape(new Rectangle(Color.BLUE,new Point2D(50,50), new Point2D(100,100)));
+        List<Point2D> points = new ArrayList<>();
+        points.add(new Point2D(20,20));
+        points.add(new Point2D(30,30));
+        //points.add(new Point2D(80,80));
+
+        shapeContainer.addShape(new Polygon(Color.BLACK,points));
         shapeContainer.draw(graphicsContext);
         root.getChildren().add(canvas);
         primaryStage.setScene(new Scene(root));

src/main/java/shape/BorderDecorator.java

@@ -19,5 +19,11 @@ public class BorderDecorator extends Decorator{
     @Override
     protected void drawDecoration(GraphicsContext graphicsContext) {
         List<Point2D> list = new ArrayList<>();
+        for(int index = 0 ; index<pointsCount() ; index++){
+            list.add(point(index));
+        }
+        for(Point2D point : list){
+            graphicsContext.strokeOval(point.getX(),point.getY(),radius,radius);
+        }
     }
 }

src/main/java/shape/CenterDecorator.java

+package shape;
+
+import javafx.scene.canvas.GraphicsContext;
+
+public class CenterDecorator extends Decorator {
+
+    double radius;
+
+    public CenterDecorator(Shape decoratedShape, double radius) {
+        super(decoratedShape);
+        this.radius = radius;
+    }
+
+    @Override
+    protected void drawDecoration(GraphicsContext graphicsContext) {
+
+    }
+}

src/main/java/shape/Circle.java

@@ -3,19 +3,10 @@ package shape;
 import javafx.geometry.Point2D;
 import javafx.scene.canvas.GraphicsContext;
 
-public class Circle implements Shape {
+public class Circle extends AbstractShape implements Shape {
 
     public Circle(double x, double y, double sqrt) {
-    }
 
-    @Override
-    public int pointsCount() {
-        return 0;
-    }
-
-    @Override
-    public Point2D point(int index) {
-        return null;
     }
 
     @Override

src/main/java/shape/Polygon.java

@@ -23,6 +23,7 @@ public class Polygon extends AbstractShape {
             coordinateX[index]=point(index).getX();
             coordinateY[index]=point(index).getY();
         }
-        context.strokePolygon(coordinateX,coordinateY,pointsCount());
+        context.setFill(color);
+        context.fillPolygon(coordinateX,coordinateY,pointsCount());
     }
 }

src/main/java/shape/Rectangle.java

@@ -19,7 +19,9 @@ public class Rectangle extends AbstractShape implements Shape{
 
     @Override
     public void draw(GraphicsContext context) {
-          context.strokeRect(point(0).getX(),point(0).getY(),point(1).getX()-point(0).getX(),
-                  point(1).getY()-point(0).getY());
+        context.setFill(color);
+        context.fillRect(point(0).getX(),point(0).getY(),(point(1).getX())-(point(0).getX()),
+                (point(1).getY())-(point(0).getY()));
+
     }
 }
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