import java.applet.*;
import java.awt.event.*;
import java.awt.*;
import javax.swing.*;

public class MoveGraphics extends JPanel {
    
    int cursorX = 100;
    int cursorY = 100;
    int width = 20;
    int height = 20;
    boolean dragging = false;
    
    public MoveGraphics() {
	addMouseMotionListener(new MouseMotionAdapter() {
		public void mouseDragged(MouseEvent e) {
		    int x = e.getX();
		    int y = e.getY();
		    Rectangle r = new Rectangle(cursorX, cursorY, width, height);
		    
		    //Must check for dragging in the if-statement
		    //below because the cursor might get outside
		    //the rectangle while dragging.
		    if (r.contains( x, y ) || dragging) {
			//User starts dragging.
			dragging = true;
			cursorX = e.getX();
			cursorY = e.getY();
			repaint();
		    }
		}
	    });
	
	addMouseListener(new MouseAdapter() {
		public void mouseReleased(MouseEvent e) {
		    //User stops dragging.
		    dragging = false;
		}
	    });
    }
    
    public void paintComponent(Graphics g) {
	//This is were drawing is done. Do not touch the paint
	//method.
	
	//Call super or the panels background will not 
	//be redrawn.
	super.paintComponent(g);
	
	//Draw the rectangle where the user has placed it.
	g.drawRect(cursorX, cursorY, width, height);
    }
    
    public static void main(String[] args) {
	JFrame f = new JFrame("simple drag and drop");
	f.getContentPane().add(new MoveGraphics(), BorderLayout.CENTER);
	
	f.addWindowListener(new WindowAdapter() {
		public void windowClosing(WindowEvent e) {
		    e.getWindow().dispose();
		    System.exit(0);
		}
	    } );
	
	f.setSize(300, 300);
	f.setVisible(true);
    }
    
}