// File: TestScrollbar2.java (Module 11)
//
// Author: Rahul Simha
// Created: November 4, 1998.
//
// Demonstrates keyboard events.

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());

    Panel p = new Panel ();
    p.setLayout (new GridLayout (4,1));

    c = new Canvas ();
    c.setBackground (Color.white);

    // A KeyListener for the canvas.
    c.addKeyListener (getKeyListener());

    p.add (c);

    // A local class:
      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());
    // A KeyListener for the scrollbar.
    red_bar.addKeyListener (getKeyListener());
    p.add (red_bar);

    green_bar = new Scrollbar (Scrollbar.HORIZONTAL, 0, 10, 0, 255);
    green_bar.addAdjustmentListener (new ColorAdjustmentListener());
    // A KeyListener for the scrollbar.
    green_bar.addKeyListener (getKeyListener());
    p.add (green_bar);

    blue_bar = new Scrollbar (Scrollbar.HORIZONTAL, 0, 10, 0, 255);
    blue_bar.addAdjustmentListener (new ColorAdjustmentListener());
    // A KeyListener for the scrollbar.
    blue_bar.addKeyListener (getKeyListener());
    p.add (blue_bar);

    this.add (p, BorderLayout.CENTER);

    Button quitb = new Button ("Quit");
    quitb.setBackground (Color.red);
    quitb.setFont (new Font ("Serif", Font.PLAIN | Font.BOLD, 15));
    quitb.addKeyListener (getKeyListener());
    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 ();
  }


  // Create a KeyListener to be used everywhere.

  KeyListener getKeyListener ()
  {
    return new KeyAdapter () {
      public void keyPressed (KeyEvent k)
      {
	if (k.getKeyCode() == KeyEvent.VK_Q)
  	  // "q" for quit.
	  System.exit (0);
	else if (k.getKeyCode() == KeyEvent.VK_LEFT) {	  
	  // Left arrow.
          red_bar.setValue (Math.max (0, red_value-10));
	  adjust ();
	}
	else if (k.getKeyCode() == KeyEvent.VK_RIGHT) {
	  // Right arrow.
	  red_bar.setValue (Math.min (255, red_value+10));
	  adjust ();
	}
      }
    };
  }

}


public class TestScrollbar2 {
  public static void main (String[] argv)
  {
    NewFrame nf = new NewFrame (500, 300);
  }
}