import java.awt.*;
import java.awt.geom.*;

/**
 * A circle that can be manipulated and that draws itself on a canvas.
 */

public class SimpleCircle
{
    private int xPosition;
    private int yPosition;
    private String color;
        
    /**
     * Create a new circle at default position with default color.
     */
    public SimpleCircle()
    {
        xPosition = 20;
        yPosition = 60;
        color = "blue";
        draw();
    }


    /**
     * Move the circle horizontally by 'distance' pixels.
     */
    public void moveHorizontal(int distance)
    {
        erase();
        xPosition += distance;
        draw();
    }

    /**
     * Move the circle vertically by 'distance' pixels.
     */
    public void moveVertical(int distance)
    {
        erase();
        yPosition += distance;
        draw();
    }

    /**
     * Change the color. Valid colors are "red", "yellow", "blue", "green",
     * "magenta" and "black".
     */
    public void changeColor(String newColor)
    {
        erase();
        color = newColor;
        draw();
    }

    /**
     * Make the circle dance around
     */
    public void doCircleDance()
    {
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);
        moveHorizontal(1);

        moveVertical(80);
        moveHorizontal(-80);
        moveVertical(-80);

        
    }

    // How far is the circle from (0,0)?
    public double calcOriginDistance()
    {
        //get x & y position, square them, and take the square root
        double distance;
        distance = xPosition*xPosition + yPosition*yPosition;
        distance = Math.sqrt(distance);
        
        return distance;
    }


    //Print out the circle’s distance from the origin
    public void printOriginDistance()
    {
        System.out.println((int)calcOriginDistance());
    }

    
    /*
     * Draw the circle with current specifications on screen.
     */
    private void draw()
    {
        Canvas canvas = Canvas.getCanvas();
        Ellipse2D theEllipse = new Ellipse2D.Double(xPosition, yPosition, 20, 20);        
        canvas.draw(this, color, theEllipse); 
        canvas.wait(10);
    }

    /*
     * Erase the circle on screen.
     */
    private void erase()
    {
        Canvas canvas = Canvas.getCanvas();
        canvas.erase(this);
    }
}