OpenClosedPrincipleproblem/CompositeShape.java

import java.util.ArrayList;
import java.util.List;

public class CompositeShape implements Shape, Resizable {
    private List<Shape> shapes;
    private String color;
    
    public CompositeShape(String color) {
        this.shapes = new ArrayList<>();
        this.color = color;
    }
    
    public CompositeShape() {
        this("Default");
    }
    
    // Add a shape to the composite
    public void addShape(Shape shape) {
        if (shape != null) {
            shapes.add(shape);
        }
    }
    
    // Remove a shape from the composite
    public boolean removeShape(Shape shape) {
        return shapes.remove(shape);
    }
    
    // Get all shapes in the composite
    public List<Shape> getShapes() {
        return new ArrayList<>(shapes); // Return a copy to prevent external modification
    }
    
    @Override
    public double calculateArea() {
        // Total area is the sum of areas of all child shapes
        double totalArea = 0;
        for (Shape shape : shapes) {
            totalArea += shape.calculateArea();
        }
        return totalArea;
    }
    
    @Override
    public double calculatePerimeter() {
        // For composite shape, perimeter is more complex to calculate
        // For simplicity, we'll sum the perimeters of all child shapes
        // Note: This is not geometrically accurate for overlapping shapes
        double totalPerimeter = 0;
        for (Shape shape : shapes) {
            totalPerimeter += shape.calculatePerimeter();
        }
        return totalPerimeter;
    }
    
    @Override
    public String getColor() {
        return color;
    }
    
    @Override
    public void setColor(String color) {
        this.color = color;
        // Optionally, we could also set the color of all child shapes
    }
    
    @Override
    public void resize(double factor) {
        // Resize all child shapes that implement Resizable
        for (Shape shape : shapes) {
            if (shape instanceof Resizable) {
                ((Resizable) shape).resize(factor);
            }
        }
    }
    
    @Override
    public void resizeWidth(double factor) {
        // Resize width of all child shapes that implement Resizable
        for (Shape shape : shapes) {
            if (shape instanceof Resizable) {
                ((Resizable) shape).resizeWidth(factor);
            }
        }
    }
    
    @Override
    public void resizeHeight(double factor) {
        // Resize height of all child shapes that implement Resizable
        for (Shape shape : shapes) {
            if (shape instanceof Resizable) {
                ((Resizable) shape).resizeHeight(factor);
            }
        }
    }
    
    // Set color for all child shapes
    public void setAllShapesColor(String color) {
        for (Shape shape : shapes) {
            shape.setColor(color);
        }
    }
    
    // Get the number of shapes in the composite
    public int getShapeCount() {
        return shapes.size();
    }
    
    @Override
    public String toString() {
        return "CompositeShape [color=" + color + ", shapeCount=" + shapes.size() + "]";
    }
}