// File: OneCanvas.java (Module 10)
//
// Author: Rahul Simha
// Created: November 2, 1998
//
// A single canvas

import java.awt.*;
import java.awt.event.*; // Needed for ActionListener.

class NewFrame extends Frame {

  // Data.
  int current_x=0, current_y=0;
  Canvas c;

  // Constructor.
  public NewFrame (int width, int height)
  {
    // Set the title and other frame parameters.
    this.setTitle ("Panel and canvas example");
    this.setResizable (true);
    this.setBackground (Color.cyan);
    this.setSize (width, height);
    // this.setLayout (new BorderLayout());

    // Create a quit button.
    Button quitb = new Button ("Quit");
    quitb.setBackground (Color.red);
    quitb.setFont (new Font ("Serif", Font.PLAIN | Font.BOLD, 15));
    // Using an anonymous class:
    quitb.addActionListener (
      new ActionListener() {
        public void actionPerformed (ActionEvent a) 
        {
	  System.exit(0);
        }
      }
    );

    this.add (quitb, BorderLayout.SOUTH);

    // Create a white canvas.
    c = new Canvas ();
    c.setBackground (Color.white);
    c.setForeground (Color.blue);

    // Using an anonymous class:
    c.addMouseListener (
      new MouseAdapter () {
        public void mouseClicked (MouseEvent m)
	{
	  int x = m.getX();
	  int y = m.getY();
	  Graphics g = c.getGraphics();
	  g.drawLine (current_x, current_y, x, y);
	  current_x = x;
	  current_y = y;
	}
      }
    );

    // Add canvas to frame in the center.
    this.add (c, BorderLayout.CENTER);

    // Create a Panel
    Panel p = new Panel ();
    p.setLayout (new FlowLayout());

    // Create a clear button.
    Button clearb = new Button ("Clear");
    clearb.setBackground (Color.green);

    // Using an anonymous class:
    clearb.addActionListener (
      new ActionListener () {
        public void actionPerformed (ActionEvent a)
	{
	  c.setBackground (Color.white);
	  c.repaint();
	  current_x = current_y = 0;
	}
      }
    );

    p.add (clearb);

    // Now add the panel to the frame.
    this.add (p, BorderLayout.NORTH);

    // Show the frame.
    this.setVisible (true);
  }



} // End of class "NewFrame"


public class OneCanvas {

  public static void main (String[] argv)
  {
    NewFrame nf = new NewFrame (300, 200);
  }

}