public interface Drawing {
    
    void setOrigin( int x0, int y0);
    
    void Draw(java.awt.Graphics g);

    void setX(int x);
    
    void setY(int y);
    
    int getX();
    
    int getY();
}

public abstract class  shape implements Drawing
    
  
    protected int x0=0,y0=0;
    protected int x=0,y=0;      
    
    
    public shape(int x, int y){
        this(0,0,x,y);
    }
    
    public shape(int x0,int y0, int x, int y) {

   this.x0=x0;
        this.y0=y0;
        this.x=x;
        this.y=y;
    }

    public void setOrigin(int x0, int y0) {
        this.x0=x0;
        this.y0=y0;        
    }
    

    public void setY(int y) {
        this.y=y;
    }

    public void setX(int x) {
        this.x=x;
    }

    public int getY() {
        return y;
    }
    public int getX() {
        return x;
    }
    
    public abstract void Draw(java.awt.Graphics g);
}

public class Circle extends shape{

    private int radius;
    public Circle(int x, int y, int radius ) {
        super(x,y);
        this.radius=radius;
    }
    
    public void setRadius(int r){
        if(r >=0 )radius=r;
    }

    public void Draw(java.awt.Graphics g) {
        g.drawOval(x+x0-radius,y0-y-radius, radius*2, radius*2);
    }
    
    
}

public class Rectangle extends shape{
    
    private int height,width;
    
  
    public Rectangle(int x,int y) {    
        super(x,y);
    }
    public Rectangle(int x ,int y,int width ,int height){
        super(0, 0,x,y);
        setWidth(width);
        setHeight(height);
    }    
    
        
    public void setWidth(int w){
        if( w > 0 )width=w;
    }
    
    public void setHeight(int h){
        if(h > 0)height=h;
    }
    
    public int getWidth(){return width;}
    
    public int getHeight(){return height;}

    public void Draw(java.awt.Graphics g) {
        g.drawRect(x0+x, y0-y, width,height);
    }
          
}    

import javax.swing.JApplet;
import java.awt.Graphics;
import java.awt.Color;
public class XYPlane extends JPanel {
    
    private XYShape[] dr;
    private Color BackColor=Color.WHITE;
    private int count=0;
    public void init(){
        dr=new XYShape[100];
    }  
    
    public void Add(XYShape d){
        if(d!=null){
            dr[count]=d;
            count++;
        }
    }  
    
    public void setBackColor(Color c){
        if(c!=null)BackColor=c;
    }
    
   public void DrawAxis(Graphics g){
        g.setColor(Color.BLACK);
        g.drawLine(0, getHeight()/2, getWidth(), getHeight()/2 );
        g.drawLine( getWidth()/2 , 0, getWidth()/2, getHeight());        
   }
  
   public void paint(Graphics g){
        
        Color c=g.getColor();
        g.setColor(BackColor);
        g.fillRect(0,0,getWidth(), getHeight());
        g.setColor©;
        DrawAxis(g);        
        int i=0;
        while(i < count ){                    
            dr[i].setOrigin(getWidth()/2 ,getHeight()/2);
            dr[i].Draw(g);
            i++;
        }

        
   }
    
}