Java-program för att flytta objekt (hjälp!)

public class Square {
public Square(Graphics g, int width, int height, int x, int y){
g.setColor(Color.RED);
g.fillRect(x, y, width, height);
}
}

public class Circle {
public Circle(Graphics g, int diameter, int x, int y){
g.setColor(Color.RED);
g.fillOval(x, y, diameter, diameter);
}
}

public class Triangle {
public Triangle(Graphics g, int width, int height, int x, int y){
Polygon triangle = new Polygon();
triangle.addPoint(x+width/2, y);
triangle.addPoint(x, height+y);
triangle.addPoint(x+width, height+y);
g.setColor(Color.RED);
g.fillPolygon(triangle);
}
}

import java.awt.Graphics;
import java.awt.event.*;
import javax.swing.JPanel;

public class MyDraggableComponent extends JPanel {
private Square S;
private Circle C;
private Triangle T;
// rita en cirkel, en kvadrat, samt en triangel
@Override
public void paintComponent(Graphics g) {
if (Shape == "S") {
S = new Square(g, 100, 100, 0, 0);
} else if (Shape == "C"){
C = new Circle(g, 100, 0, 0);
} else if (Shape == "T"){
T = new Triangle(g, 100, 100, 0, 0, true);
}
}

private volatile int screenX = 0;
private volatile int screenY = 0;
private volatile int myX = 0;
private volatile int myY = 0;
private String Shape; // FORM

public MyDraggableComponent(int h, int w, String Shapevalue) {

// ange vilken form som ska skapas
Shape = Shapevalue;
setBackground(Color.WHITE);
setBounds(0, 0, h, w);
setOpaque(false);

addMouseListener(new MouseListener() {

@Override
public void mouseClicked(MouseEvent e) { }

@Override
public void mousePressed(MouseEvent e) {
screenX = e.getXOnScreen();
screenY = e.getYOnScreen();
myX = getX();
myY = getY();
}

@Override
public void mouseReleased(MouseEvent e) { }

@Override
public void mouseEntered(MouseEvent e) { }

@Override
public void mouseExited(MouseEvent e) { }

});

addMouseMotionListener(new MouseMotionListener() {

@Override
public void mouseDragged(MouseEvent e) {
int deltaX = e.getXOnScreen() - screenX;
int deltaY = e.getYOnScreen() - screenY;
setLocation(myX + deltaX, myY + deltaY);
}

@Override
public void mouseMoved(MouseEvent e) { }

});

}

}

import javax.swing.JFrame;
import javax.swing.JPanel;

public class Mitt_program{

public static void main(String[] args) {
JFrame f = new JFrame("Uppgift 3");
f.setLayout(null);

// skapa en cirkel, en kvadrat samt en triangel
MyDraggableComponent Shape1 = new MyDraggableComponent(100, 100, "C");
MyDraggableComponent Shape2 = new MyDraggableComponent(99, 99, "S");
MyDraggableComponent Shape3 = new MyDraggableComponent(101, 101, "T");

// addera objekten
f.add(Shape1);
f.add(Shape2);
f.add(Shape3);

f.setSize(500, 500);
f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE );
f.setVisible(true);
}

}