// filename: Circles1.java
import java.applet.*;
import java.awt.*;

public class Circles1 extends Applet
{
    public void paint(Graphics g)
    {
	int i, y, width, height, size;
	width = getSize().width; 
	height = getSize().height;
	size = width / 10; y = height / 2;
		
	for (i = 0; i < 10; i = i + 1)
	    {
		if (i % 2 == 0)	
		    g.setColor(Color.red);
		else 
		    g.setColor(Color.green);
		g.fillOval(i * size, y, size, size);
	    }

	/* more efficient version using addition operation
	for (i = 0, x = 0; i < 10; i = i + 1, x = x + size)
	    {
		if (i % 2 == 0)
		    g.setColor(Color.red);
		else
		    g.setColor(Color.green);
		g.fillOval(x, y, size, size);
	    }
	// Alternating Between Three Colors
	for (i = 0, x = 0; i < 10; i = i + 1, x = x + size)
	    {
		if (i % 3 == 0) g.setColor(Color.red);
		else if (i % 3 == 1) g.setColor(Color.green);
		else if (i % 3 == 2) g.setColor(Color.blue);
		
		g.fillOval(x, y, size, size);
	    }
 	*/   
    }	
}

// filename: Circles5.java
import java.applet.*;
 import java.awt.*;

 public class Circles5 extends Applet
 {
     public void paint(Graphics g)
     {
         int row, col, x, y, width, height, sizeX, sizeY;
         width = getSize().width;
         height = getSize().height;
         sizeX = width / 10; sizeY = height / 5;

         for (col = 0; col < 10; col = col + 1)
             for (row = 0; row < 5; row = row + 1)
                 g.drawOval(col * sizeX, row * sizeY, sizeX, sizeY);

	/* more efficient version 
	for (x = 0; x < width; x = x +  sizeX)
	    for (y = 0; y < height; y = y + sizeY)
		g.drawOval(x, y, sizeX, sizeY);
    	*/   
     }
 }

// filename: Circles8.java
import java.applet.*;
import java.awt.*;

public class Circles8 extends Applet
{
    public void paint(Graphics g)
    {
	int x, y, r, width, height, sizeX, sizeY;
	width = getSize().width;
	height = getSize().height;
	sizeX = width / 10; sizeY = height / 5;

	int color = 0;
		
	for (x = 0; x < width; x = x + sizeX)
	    for (y = 0; y < height; y = y + sizeY)
		for (r = 10; r > 0; r = r - 2, color = color+1)
		    {
			if (color % 3 == 0) g.setColor(Color.red);
			else if (color % 3 == 1) g.setColor(Color.green);
			else if (color %3 == 2) g.setColor(Color.blue);

			g.drawOval(x + r, y + r, sizeX - 2*r, sizeY - 2*r);
		    }
    }
}

// filename: AnimationApplet.java
import java.awt.*;
import java.applet.*;
import java.awt.event.*;

public class AnimationApplet extends Applet implements ActionListener
{
    public Button b;
    public int width, size, x, y;
    
    public void init( )
    {
	b = new Button("Animate Now");
	b.addActionListener(this);
	add(b);
    }
    
    public void actionPerformed(ActionEvent e)
    {
	int i;
	Graphics g = getGraphics();
	g.setColor(Color.blue);
	width = getSize().width;
	y = getSize().height/2;
	size = width / 10;
      
	for (x = 0; x + size < width; x = x+1)
	    {
		g.fillOval(x, y, size, size); 
		for (i = 0; i < 1000000; i = i+1);
	    }
    }
}