Game.java

/**
 * Name: Matthew Hyman
 *
 * Program Plays a Whack-a-Mole style game via a GUI. Relies upon the Creature sub-class of JButton to facilitate the interaction between the player and 
 * the moles, called creatures in the code for re-usability. The game offers the user the option to play again or end the program after each attempt to beat the game. 
 * 
 */

import javax.swing.*;
import java.awt.*; 
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.text.NumberFormat;
import java.util.*;


public class Game extends JFrame implements ActionListener{
	private static final int MAX_CREATURES = 4; //stores the max number of active creatures 
	private static final String SCORE_PREFIX = "Score: "; 
	private static final String TIME_PREFIX = "Time: "; 
	private static final double LENGTH_OF_GAME = .25*60000; //stores the length of the game in milliseconds
	private static final int TARGET_SCORE = 200; //stores the score the player must get to beat the level 
	private static final int MAX_LEVEL = 4; //stores the number of the last level in the game  
	private static final int CREATURES_PER_LEVEL = 6; //stores the number of the creatures to increment by for each level  
	private static Random rand = new Random(); 
	private static  int numOfCreatures = 6; //stores the number of creatures, varies with the level the player is currently on  
	private static int level = 1; //stores the level the player is currently on  
	static int score; //store the numerical score of the game 
	static JLabel scoreLabel; //displays the score of the game
	static JLabel timeLabel; //displays the time left in the game
	public static int creaturesAlive; //stores the number of creatures that are currently alive
	
	Creature[] creatures; //stores the creatures in the game 
	
	
	
	
	public static void main(String[] args) {
		//create an instance of the game and display start message 
		Game this_game = new Game(); 
		JOptionPane.showMessageDialog(this_game, "Instructions: Click on a green space to get 10 points.\n  There are " + MAX_LEVEL + 
												" levels. Each level will last 15 seconds.\n You need to get " + TARGET_SCORE + " points to move onto the next level. Good luck.");
		
		//loop to enable the user the continuously replay the game, the loop ends when the player chooses to not replay the game at the end of the game
		while(true) {
			
			//keep playing levels until the player does not reach target score or the last level is played 
			while(level <= MAX_LEVEL) {
				
				//announce level number and number of creatures to warn player before timer starts 
				JOptionPane.showMessageDialog(this_game, "Level " + level + "\n Number of Moles: " + numOfCreatures + "\n Press OK to begin level.");
				
				//play the level 
				this_game.playGame(); 
				
				//if target score is not reached end the game 
				if(score < TARGET_SCORE) {
					JOptionPane.showMessageDialog(this_game, "Level " + level + " Score: " + score + "\n Did not get to " + TARGET_SCORE + " points.  Game Over");
					break; 
					}
				
				//increment appropriate values to prepare  for next level 
				nextLevel();
				
				//if there are levels left to play then re-instantiate Game to reflect changes
				if(level <= MAX_LEVEL) {
					this_game.dispose();
					this_game = new Game();
				}   	
			}
			
			//if player has beat the last level display success message 
			if(level > MAX_LEVEL)
				JOptionPane.showMessageDialog(this_game, "Congratulations, you have won the game!");
			
			//display ending screen where the player decides to play again or not 
			int response = JOptionPane.showConfirmDialog(this_game, "Thank you for playing!\n Do you want to play again?", "Play Again?", JOptionPane.YES_NO_OPTION, JOptionPane.QUESTION_MESSAGE);
			
			//if the player decides not to play again or closes the box exit the loop to begin closing the game, otherwise let the game re-set itself
			if (response == JOptionPane.NO_OPTION || response == JOptionPane.CLOSED_OPTION) 
				break; 
			
			//to facilitate playing the game again reset the appropriate variables to the way they were at the start of the game and re-instantiate the game to reflect the changes
			resetLevel(); 
			this_game.dispose();
			this_game = new Game();
		
		}
		
		//dispose of game hence ending the program 
		this_game.dispose(); 
		 

	}
	//updates the time left in the game setting the value 
	//displayed by the time label equal to the time remaining 
	//variable 
	public static void update_time(double timeRemaining) {
		//update the time label 
		timeLabel.setText(TIME_PREFIX + NumberFormat.getInstance().format(timeRemaining/1000)); 		
	}
	
	//increments the score variable while updating the score label
		public static void update_score() {
			score += 10; 
			scoreLabel.setText(SCORE_PREFIX + score); 		
		}
	
	public Game() {
		//set JFrames size, layout, close operation, and title 
		setSize(500, 500); 
		setLayout(new BorderLayout()); 
		this.setDefaultCloseOperation(EXIT_ON_CLOSE);
		this.setTitle("Whack-a-Mole"); 
		
		//set score and creatures alive to 0 for the current game/level 
		score = 0; 
		creaturesAlive = 0; 
		
		//Initialize and add top of the screen 
		JPanel top = intitialize_top(); 
		add(top, BorderLayout.NORTH);
		
		//Initialize and add the play field 
		JPanel field = intitialize_field(); 
		add(field, BorderLayout.CENTER);
		
		//set as being visible
		this.setVisible(true); 
		
		
	}
	
	//Initializes the play field with all the creatures and sets their action listeners to the game 
	private JPanel intitialize_field() {
		//create field panel and set up grid layout 
		JPanel field = new JPanel(); 
		field.setLayout(new GridLayout(4,3, 5, 5)); 
		//Initialize creatures array 
		creatures = new Creature[numOfCreatures]; 
		for(int x = 0; x < creatures.length; x++) {
			creatures[x] = new Creature();
			creatures[x].addActionListener(this); 
			field.add(creatures[x]); 	
		}
		return field; 
		
	}
	
	//Initializes the top of the game screen with the score label
	private JPanel intitialize_top() { 
		
		//Initialize top JPanel 
		JPanel top = new JPanel(); 
		top.setLayout(new GridLayout(1,2)); 
		
		//Initialize and add score and time label to JPanel 
		scoreLabel = new JLabel(); 
		timeLabel = new JLabel(); 
		scoreLabel.setText(SCORE_PREFIX);
		timeLabel.setText(TIME_PREFIX);
		top.add(scoreLabel); 
		top.add(timeLabel); 
		
		return top; 
	}
	
	//play the game with its current level and creature information 
	private void playGame() {
		double startTime = new Date().getTime(); //stores the start of the game   
		double currentTime = startTime; //stores the current time each frame is rendered to allow comparison to start time 
		double timeRemaining = LENGTH_OF_GAME; //stores the time left in the game   
		
		//play game until the length of the game as been reached  
		while(( LENGTH_OF_GAME - timeRemaining) < LENGTH_OF_GAME) {
			
			// Measure the current time in an effort to keep up a consistent
			// frame rate
			long time = System.currentTimeMillis();
			
			reviveCreatures(); 
			updateCreatures(); 
			
			// Sleep until it's time to draw the next frame 
			// (i.e. 32 ms after this frame started processing)
			try{
				long delay = Math.max(0, 32-(System.currentTimeMillis()-time));
				
				Thread.sleep(delay);
				}
			catch(InterruptedException e)
			{
					
			}
			
			//update time variable  
			currentTime = new Date().getTime(); 
			
			//calculate how much time is left in the game 
			timeRemaining = LENGTH_OF_GAME - (currentTime - startTime);
			
			//update time label 
			update_time(timeRemaining); 
			
			
		}
		
		
	}
	
	//updates all the creatures in the game by incrementing their life count if necessary 
	//and killing them if their life is up
	private void updateCreatures() {
		for(int x = 0; x < creatures.length; x++)
			creatures[x].update(); 
	}
	
	//if the max number of creatures are not currently alive attempts to revive a creature
	//note: is intended to accidently revive already alive creature for randomness purposes 
	private void reviveCreatures() {
		if (creaturesAlive < MAX_CREATURES) {
			//no +1 because of array indexes being length-1 
			int randomCreature = rand.nextInt(numOfCreatures); 
			//if creature is not alive revive it 
			if(!creatures[randomCreature].getIsAlive()) {
				creatures[randomCreature].revive(); 
				creaturesAlive++; 
			}
		}
	}
	
	//updates the level and numOfCreatures value for the next level 
	private static void nextLevel() {
		//increment the level by one and set the number of creatures equal to the creatures per level number times the level the game is currently on 
		level++; 
		numOfCreatures = CREATURES_PER_LEVEL * level; 
	}
	
	//resets the level and numOfCreatures value to the way they were at the start of the game 
	private static void resetLevel() {
		//increment the level by one and set the number of creatures equal to the creatures per level number times the level the game is currently on 
		level = 1; 
		numOfCreatures = CREATURES_PER_LEVEL; 
	}
	

	//if the player clicks a creature and it is alive kill it and add points to score
	public void actionPerformed(ActionEvent event) {
		Creature clickedCreature = (Creature) event.getSource();
		//if the clicked creature is alive kill it and call update score function 
		if(clickedCreature.getIsAlive()) {
			clickedCreature.kill();
			update_score(); 
		}
		
	}
	
}