// ShowPoint.java: Show point coordinates when user clicks mouse.
// You can execute this as program (java ShowPoint) or applet
// (appletviewer ShowPoint.html or double-click on icon).
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class ShowPoint extends JApplet
  implements MouseListener
{
  // Point is a Java object for representing points in a plane.
  // p.x and p.y are the x and y coordinates.
  private Point p = new Point(0, 0);

  public void init()
  {
    // Register ShowPoint object (this) as listener for mouse events.
    addMouseListener(this);
  }

  // Main method
  public static void main(String[] args)
  {
    // Create frame with title.
    JFrame frame = new JFrame("Click to Show Point Coordinates");

    // Create instance of ShowPoint.
    ShowPoint applet = new ShowPoint();

    // Add applet instance to frame.
    frame.getContentPane().add(applet, BorderLayout.CENTER);

    // Add window listener interface using anonymous class.
    // Use adapter class so it implements all seven methods.
    frame.addWindowListener(new WindowAdapter()
    {
      // Quit application when quitting frame, else you must do CTRL-c.
      public void windowClosing(WindowEvent event)
      {
        System.exit(0);
      }
    });

    // Invoke init() and start().
    applet.init();
    applet.start();

    frame.setSize(600, 300);
    frame.setVisible(true);
  }

  // MouseListener has five listener methods (handlers). You must
  // define all methods. You can avoid having to explicitly do
  // this by using an adapter class. The MouseAdapter adapter
  // class implements the MouseListener interface.
  public void mousePressed(MouseEvent e)
  {}

  public void mouseReleased(MouseEvent e)
  {}

  public void mouseEntered(MouseEvent e)
  {}

  public void mouseExited(MouseEvent e)
  {}

  // Listener reacts to click, right-click, or double-click.
  // Point p holds mouse pointer location.
  public void mouseClicked(MouseEvent e)
  {
    p.x = e.getX();
    p.y = e.getY();
    repaint();
  }

  // Draw small square around point followed by coordinates.
  public void paint(Graphics g)
  {
    g.drawRect(--p.x, --p.y, 2, 2);
    g.drawString("("+p.x+", "+p.y+")", p.x, p.y);
  }
}