GD - Circle.java

package gd;

import java.awt.Graphics;

/**
 * A specific shape: A circle.
 * This cirlce inherits from Shape
 * @author hypesystem
 * @email  [email protected]
 */
public class Circle extends Shape implements Drawable, DrawableAndMovable {
    private double r;

    /**
     * Creates a circle witout a coordinate argument (sets coordinates to 0,0).
     * @param r radius of circle
     */
    public Circle(double r) {
        super(new Coordinate(0,0));
        setAttr(r);
    }

    /**
     * Creates a circle with a coordinate argument.
     * @param r radius of circle
     * @param coordinates coordinates of circle
     */
    public Circle(double r, Coordinate coordinates) {
        super(coordinates);
        setAttr(r);
    }

    /**
     * Sets the attributes of the Circle. Called from constructors (hence
     * private)
     * @param r radius of circle
     */
    private void setAttr(double r) {
        this.r = r;
    }

    /**
     * Calculates and returns the circumference of the circle. Inherited from
     * Shape.
     * @return circumference of circle
     */
    @Override
    public double circumference() {
        return (2 * r * Math.PI);
    }

    /**
     * Calculates and returns the area of the circle Inherited from Shape.
     * @return area of circle
     */
    @Override
    public double area() {
        return (r * r * Math.PI);
    }

    /**
     * Counts the amount of simple shapes in this shape. This is a simple shape.
     * Inherited from Shape.
     * @return 1
     */
    @Override
    public int countSimple() {
        return 1;
    }

    /**
     * Draws the cirlce to a specified graphic. Implemented from Drawable.
     * @param g graphic to draw to
     */
    @Override
    public void draw(Graphics g) {
        g.fillOval(getCoordinate().getX(), getCoordinate().getY(),
                (int)(2*r), (int)(2*r));
    }
}