-Buffer.java------------------------------------------------------------------

public class Buffer{
	private int[][] cells;
	private int width, height;
	
	public Buffer(int y, int x){
		width = x;
		height = y;
		cells = new int[y][x];
	}
	
	public void clear(){
		for(int y=0;y<height;y++){
			for(int x=0;x<width;x++){
				cells[y][x]=0;
			}
		}
	}
	public void random(){
		for(int y=0;y<height;y++){
			for(int x=0;x<width;x++){
				cells[y][x]=(int)(Math.random()*2);
			}
		}
	}
	
	public int getCell(int y, int x){
		return cells[y][x];
	}
	
	public void setCell(int y, int x, int value){
		cells[y][x]=value;
	}
	
	public int numNeighbors(int y, int x){
		int numLivingNeighbors=0;
		if(cells[(height+y-1)%height][(width+x-1)%width]>0)
			numLivingNeighbors++;
		if(cells[(height+y-1)%height][x]>0)
			numLivingNeighbors++;
		if(cells[(height+y-1)%height][(width+x+1)%width]>0)
			numLivingNeighbors++;
	
		if(cells[y][(width+x-1)%width]>0)
			numLivingNeighbors++;
		if(cells[y][(width+x+1)%width]>0)
			numLivingNeighbors++;
	
		if(cells[(height+y+1)%height][(width+x-1)%width]>0)
			numLivingNeighbors++;
		if(cells[(height+y+1)%height][x]>0)
			numLivingNeighbors++;
		if(cells[(height+y+1)%height][(width+x+1)%width]>0)
			numLivingNeighbors++;
		
		return numLivingNeighbors;
	}
}


-LifeCanvas.java----------------------------------------------------------------

import java.awt.*;
import java.awt.event.*;

public class LifeCanvas extends Canvas implements MouseListener, MouseMotionListener{
	private Buffer front, back;
	private int width, height, size;
	boolean[][] changed;
	boolean auto;
	Image offscreen;
	Color[] colors;
	
	public LifeCanvas(int y, int x, int cellSize){
		height = y;
		width = x;
		size = cellSize;
		changed = new boolean[y][x];
		for(int i=0;y<height;y++){
			for(int j=0;x<width;x++){
				changed[i][j]=false;
			}
		}
		colors = new Color[10];
		colors[0]=Color.DARK_GRAY;
		for(int i=1;i<10;i++){
			colors[i]=new Color((i-1)*20,255-((i-1)*20),0);
		}
		
		front = new Buffer(height, width);
		back = new Buffer(height, width);
		auto = false;
		addMouseListener(this);
		addMouseMotionListener(this);
	}
	
	public void clear(){
		front.clear();
		back.clear();
		repaint();
	}
	
	public void  random(){
		front.random();
		repaint();
	}
	
	public void autoFire(){
		if(auto){
			doTurn();
		}
	}
	
	public void doTurn(){
		for(int y=0;y<height;y++){
			for(int x=0;x<width;x++){
				int numNeighbors=front.numNeighbors(y,x);
				if(numNeighbors<2)
					back.setCell(y,x,0);
				if(numNeighbors==2){
					if(front.getCell(y,x)>0){
						if(front.getCell(y,x)<9){
							back.setCell(y,x,front.getCell(y,x)+1);
						}else{
							back.setCell(y,x,9);
						}
					}else{
						back.setCell(y,x,0);
					}
				}
				if(numNeighbors==3){
					if(front.getCell(y,x)>0){
						if(front.getCell(y,x)<9){
							back.setCell(y,x,front.getCell(y,x)+1);
						}else{
							back.setCell(y,x,9);
						}
					}else{
						back.setCell(y,x,1);
					}
				}
				if(numNeighbors>3)
					back.setCell(y,x,0);
			}
		}
		swapBuffers();
		repaint();
	}
	
	private void swapBuffers(){
		Buffer temp = front;
		front = back;
		back = temp;
	}
	
	public void update(Graphics g){
		paint(g);
	}
	
	public void invalidate() {
		super.invalidate();
		offscreen = null;
	}
	
	public void paint(Graphics g){
		if(offscreen == null) {
		   offscreen = createImage(getSize().width, getSize().height);
		}
		Graphics og = offscreen.getGraphics();
		og.setClip(0,0,getSize().width, getSize().height);
		for(int y=0;y<height;y++){
			for(int x=0;x<width;x++){
				og.setColor(colors[front.getCell(y,x)]);
				og.fillRect(x*size,y*size,size,size);
			}
		}
		og.setColor(Color.BLACK);
		for(int i=0;i<height+1;i++){
			og.drawLine(0,i*size,width*size,i*size);
		}
		for(int i=0;i<width+1;i++){
			og.drawLine(i*size,0,i*size,height*size);
		}
		g.drawImage(offscreen, 0, 0, null);
		og.dispose();
	}

	public void mousePressed(MouseEvent event){
		Point location = event.getPoint();
		if(location.getX()<width*size && location.getY()<height*size){
			int y = (int)location.getY()/size;
			int x = (int)location.getX()/size;
			if(!changed[y][x]){
				if(front.getCell(y,x)>0){
					front.setCell(y,x,0);
				}else{
					front.setCell(y,x,1);
				}
				changed[y][x]=true;
				repaint();
			}
		}
	}
	
	public void mouseDragged(MouseEvent event){
		Point location = event.getPoint();
		if(location.getX()<width*size && location.getY()<height*size){
			int y = (int)location.getY()/size;
			int x = (int)location.getX()/size;
			if(!changed[y][x]){
				if(front.getCell(y,x)>0){
					front.setCell(y,x,0);
				}else{
					front.setCell(y,x,1);
				}
				changed[y][x]=true;
				repaint();
			}
		}
	}

	public void mouseReleased(MouseEvent arg0){
		for(int y=0;y<height;y++){
			for(int x=0;x<width;x++){
				changed[y][x]=false;
			}
		}
	}
	
	public void mouseEntered(MouseEvent arg0){}
	public void mouseExited(MouseEvent arg0){}
	public void mouseClicked(MouseEvent arg0){}
	public void mouseMoved(MouseEvent arg0){}
}


-LifeControl.java--------------------------------------------------------------

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

public class LifeControl extends JApplet implements ActionListener{
	private LifeCanvas canvas;
	private Timer auto;
	private JPanel playControl, boardControl, mainPanel, appPanel,controlPanel;
	private JButton nextTurn, toggleAuto, clear, random;
	private JComboBox delaySelect;
	
	private final int HEIGHT = 200;
	private final int WIDTH = 300;
	private final int SIZE = 3;
	
	public LifeControl(){
		setSize(WIDTH*SIZE+10,HEIGHT*SIZE+60);
		canvas = new LifeCanvas(HEIGHT, WIDTH, SIZE);
		auto = new Timer(canvas, 250);
		
		String[] items = {"1/100 second", "1/50 second", "1/10 second", "1/4 second", "1/2 second", "1 second"};
		delaySelect = new JComboBox(items);
		delaySelect.setSelectedIndex(3);
		delaySelect.addActionListener(this);
		
		nextTurn = new JButton("Next");
		nextTurn.addActionListener(this);
		
		toggleAuto = new JButton("Play");
		toggleAuto.addActionListener(this);
		
		clear = new JButton("Clear");
		clear.addActionListener(this);
		
		random = new JButton("Random");
		random.addActionListener(this);
		
		playControl = new JPanel(new BorderLayout(5,5));
		playControl.add(nextTurn, BorderLayout.WEST);
		playControl.add(toggleAuto, BorderLayout.EAST);
		
		boardControl = new JPanel(new BorderLayout(5,5));
		boardControl.add(clear, BorderLayout.WEST);
		boardControl.add(random, BorderLayout.EAST);
		
		controlPanel = new JPanel(new BorderLayout(5,5));
		controlPanel.add(playControl, BorderLayout.WEST);
		controlPanel.add(delaySelect, BorderLayout.CENTER);
		controlPanel.add(boardControl, BorderLayout.EAST);
		
		mainPanel = new JPanel(new BorderLayout(5,5));
		mainPanel.add(canvas, BorderLayout.CENTER);
		mainPanel.add(controlPanel, BorderLayout.SOUTH);
		
		appPanel = new JPanel(new BorderLayout(5,5));
		appPanel.add(mainPanel,BorderLayout.CENTER);
		appPanel.add(Box.createRigidArea(new Dimension(5,0)),BorderLayout.WEST);
		appPanel.add(Box.createRigidArea(new Dimension(5,0)),BorderLayout.EAST);
		appPanel.add(Box.createRigidArea(new Dimension(0,5)),BorderLayout.NORTH);
		appPanel.add(Box.createRigidArea(new Dimension(0,5)),BorderLayout.SOUTH);
		
		setContentPane(appPanel);
		auto.start();
	}
	
	public void actionPerformed(ActionEvent event){
		Object source = event.getSource();
		if(source == nextTurn)
			canvas.doTurn();
		if(source == clear)
			canvas.clear();
		if(source == random)
			canvas.random();
		if(source == delaySelect){
			switch(delaySelect.getSelectedIndex()){
				case 0:
					auto.setDelay(10);
					break;
				case 1:
					auto.setDelay(20);
					break;
				case 2:
					auto.setDelay(100);
					break;
				case 3:
					auto.setDelay(250);
					break;
				case 4:
					auto.setDelay(500);
					break;
				case 5:
					auto.setDelay(1000);
					break;
			}
		}
		if(source == toggleAuto){
			if(toggleAuto.getText()=="Play"){
				canvas.auto=true;
				toggleAuto.setText("Stop");
			}else{
				canvas.auto=false;
				toggleAuto.setText("Play");
			}
		}
	}

	public static class Timer extends Thread{
		LifeCanvas target;
		int delay;
	
		public Timer(LifeCanvas targ, int initDelay){
			target = targ;
			delay = initDelay;
		}
		
		public void setDelay(int newDelay){
			delay=newDelay;
		}
	
		public void run(){
			while(true){
				try{
					sleep(delay);
					target.autoFire();
				}catch(Exception e){
					e.printStackTrace();
				}
			}
		}
	}
}