// File: TestScrollbar.java (Module 11)
//
// Author: Rahul Simha
// Created: November 4, 1998.
//
// Shows how to use scrollbars.

import java.awt.*;
import java.awt.event.*;
import java.util.*;
import java.io.*;

class NewFrame extends Frame {

  // Data.

  Scrollbar             // One scrollbar for each color.
    red_bar,
    blue_bar,
    green_bar;

  int                   // Intensity value for each color.
    red_value = 0,
    blue_value = 0,
    green_value = 0;

  Canvas c;             // To display the mixed color.


  // Constructor.

  public NewFrame (int width, int height)
  {
    this.setTitle ("RGB combination");
    this.setResizable (true);
    this.setBackground (Color.cyan);
    this.setSize (width, height);
    // this.setLayout (new BorderLayout());

    // Three scrollbars and the canvas will
    // be added to a panel.
    Panel p = new Panel ();
    p.setLayout (new GridLayout (4,1));

    // The canvas on which to display the result.
    c = new Canvas ();
    c.setBackground (Color.white);
    p.add (c);

    // A local Listener for the scrollbars.
      class ColorAdjustmentListener implements AdjustmentListener {
        public void adjustmentValueChanged (AdjustmentEvent a)
	{
	  adjust ();
	}
      }

    red_bar = new Scrollbar (Scrollbar.HORIZONTAL, 0, 10, 0, 255);
    red_bar.addAdjustmentListener (new ColorAdjustmentListener());
    p.add (red_bar);

    green_bar = new Scrollbar (Scrollbar.HORIZONTAL, 0, 10, 0, 255);
    green_bar.addAdjustmentListener (new ColorAdjustmentListener());
    p.add (green_bar);

    blue_bar = new Scrollbar (Scrollbar.HORIZONTAL, 0, 10, 0, 255);
    blue_bar.addAdjustmentListener (new ColorAdjustmentListener());
    p.add (blue_bar);

    this.add (p, BorderLayout.CENTER);

    // A quit button for the application.
    Button quitb = new Button ("Quit");
    quitb.setBackground (Color.red);
    quitb.setFont (new Font ("Serif", Font.PLAIN | Font.BOLD, 15));
    quitb.addActionListener (
      new ActionListener () {
        public void actionPerformed (ActionEvent a)
	{
	  System.exit (0);
	}  
      }
    );
    this.add (quitb, BorderLayout.SOUTH);


    // Finally, show the frame.
    this.setVisible (true);
  }


  // No-parameter constructor.
  public NewFrame () 
  {
    this (500, 300);
  }


  // Create the composite color.

  public void adjust ()
  {
    // Get the new values.
    red_value = red_bar.getValue();
    green_value = green_bar.getValue ();
    blue_value = blue_bar.getValue ();

    // Set the color in each scrollbar.
    red_bar.setBackground (new Color (red_value, 0, 0));
    green_bar.setBackground (new Color (0, green_value, 0));
    blue_bar.setBackground (new Color (0, 0, blue_value));

    // Create the composite color.
    Color new_color = new Color (red_value, green_value, blue_value); 
    c.setBackground (new_color);
    c.repaint ();
  }

}


public class TestScrollbar {
  public static void main (String[] argv)
  {
    NewFrame nf = new NewFrame (500, 300);
  }
}