// An applet that says "Hello World" in a big bold font,
// with three buttons to change the color of the message.

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

public class HelloWorldJApplet extends JApplet implements ActionListener 
{

	Display display;

	public void init() 
	{
		display = new Display();

		getContentPane().add(display, BorderLayout.CENTER);

		JPanel buttonBar = new JPanel();
		buttonBar.setBackground(Color.gray);
		
		JButton redButton = new JButton("Red");
		redButton.addActionListener(this);	
		buttonBar.add(redButton);

		JButton greenButton = new JButton("Green");
		greenButton.addActionListener(this);
		buttonBar.add(greenButton);

		JButton blueButton = new JButton("Blue");
		blueButton.addActionListener(this);
		buttonBar.add(blueButton);

		getContentPane().add(buttonBar, BorderLayout.NORTH); 
	}

	class Display extends JPanel 
	{

		int colorNum;	   
		Font textFont;
						   
		Display() 
		{
			setBackground(Color.black);
			colorNum = 1;
			textFont = new Font("Serif",Font.BOLD,36);
		}
		
		void setColor(int code) 
		{
			colorNum = code;
			repaint();
		}

		public void paintComponent(Graphics g)
		{
			super.paintComponent(g);
			switch (colorNum) 
			{
				 case 1:
				 	g.setColor(Color.red);
				 	break;
				 case 2:
				 	g.setColor(Color.green);
				 	break;
				 case 3:
				 	g.setColor(Color.blue);
				 	break;
			}
			g.setFont(textFont);
			g.drawString("Hello World!", 25,50);
		}
	}

	public void actionPerformed(ActionEvent evt) 
	{
		String command = evt.getActionCommand();
				 
		if (command.equals("Red"))
			display.setColor(1);
		else if (command.equals("Green"))
			display.setColor(2);
		else if (command.equals("Blue"))
			display.setColor(3);
	}
}