import javax.swing.*;
import java.awt.*;
import java.awt.geom.*;

/**
 *
 * Implementation of Shape as a Ellipse, plus some Ellipse-specific methods.
 *
 * @author Gene Fisher (gfisher@calpoly.edu)
 *
 */
public class Ellipse extends Shape {
   
    /** The semi-major radius */
    private double major;

    /** The semi-minor axix */
    private double minor;

    /** The position of this' center */
    private Point position;

    /** Java-geometry coordinates, i.e., un-noramized from user-level
     * coordinates. */
    int x;
    int y;
    int width;
    int height;


    /**
     * Construct this by intializing the data fields to the values of the given
     * parameters.
     */
    public Ellipse(double major, double minor, Point position, 
	    Color color, boolean filled) {
        super(color, filled);
        this.major = major;
        this.minor = minor;
        this.position = position;
        jshape = new Ellipse2D.Double(
	    position.x - major, position.y + minor, major * 2, minor * 2);
    }

    /**
     * Construct this via its framing rectangle, in Java-geometry coordinates.
     */
    public Ellipse(int x, int y, int width, int height,
            Color color, boolean filled) {
        super(color, filled);
        position = new Point(x + width / 2, y - height / 2);
        major = width / 2;
	minor = height / 2;
	jshape = new Ellipse2D.Double(x, y, width, height);
    }

    /**
     *  Return this' semi-major axis.
     */
    public double getSemiMajorAxis() {
         return major;
    }

    /**
     * Return this' semi-minor axis.
     */
    public double getSemiMinorAxis() {
         return minor;
    }

    /** 
     * Set this' semi-major axis given value.
     */
    public void setSemiMajorAxis(double major) {
        this.major = major;
    }

    /** 
     * Set this' semi-minor axis given value.
     */
    public void setSemiMinorAxis(double major) {
        this.minor = minor;
    }

    /** 
     * Return this' position.
     */
    public Point getPosition() {
        return position;
    }

    /**
     * Return true if super.equals is true, and the position and major axis and
     * minor axis of the other ellipse are the same as this ellipse.
     */
    public boolean equals(Object other) {
        if (super.equals(other) == false) {
           return false;
        }

	/*
	 * Note that this cast and subsequent code are safe, since super.equals
	 * checks that other is not null and is the same class as this.
	 */
        Ellipse c = (Ellipse) other;
        return
            position.equals(c.position) &&
            major == c.major &&
            minor == c.minor;
    }

    /*-*
     * Specialized methods for Ellipse
     */
    public double getArea() {
        return Math.PI * major * minor;
    }

    public void move(Point delta) {
        // Yipee, we got public data fields in java.awt.Point!        
        position.x += delta.x;
        position.y += delta.y;
    } 

    /**
     * Return the Java AWT representation of this, as an Ellipse2D.Double.
     */
    public java.awt.Shape getAwtRep(int canvas_height) {
        return new Ellipse2D.Double(
	    position.x - major, canvas_height - position.y - minor,
	        major * 2, minor * 2);
    }

}