pinball.java

疯狂Java讲义_源码(含Java设计模式CHM

import java.awt.*;
import java.awt.event.*;
import java.util.Random;
import javax.swing.Timer;
/**
 * Description:
 * <br/>Copyright (C), 2005-2008, Yeeku.H.Lee
 * <br/>This program is protected by copyright laws.
 * <br/>Program Name:
 * <br/>Date:
 * @author  Yeeku.H.Lee [e-mail]
 * @version  1.0
 */
public class PinBall
{
	//桌面的宽度 
	private final int TABLE_WIDTH = 300;
	//桌面的高度
	private final int TABLE_HEIGHT = 400;
	//球拍的垂直位置
	private final int RACKET_Y = 340;
	//下面定义球拍的高度和宽度
	private final int RACKET_HEIGHT = 20;
	private final int RACKET_WIDTH = 60;
	//小球的大小
	private final int BALL_SIZE = 16;
	private Frame f = new Frame("弹球游戏");
	Random rand = new Random();
	//小球纵向的运行速度
	private int ySpeed = 10;
	//返回一个-0.5~0.5的比率，用于控制小球的运行方向。
	private double xyRate = rand.nextDouble() - 0.5;
	//小球横向的运行速度
	private int xSpeed = (int)(ySpeed * xyRate * 2);
	//ballX和ballY代表小球的座标
	private int ballX = rand.nextInt(200) + 20;
	private int ballY = rand.nextInt(10) + 20;
	//racketX代表球拍的水平位置
	private int racketX = rand.nextInt(200);
	private MyCanvas tableArea = new MyCanvas();
	//用于保存需要绘制什么图形的字符串属性
	private String shape = "";
	Timer timer;
	//游戏是否结束的旗标
	private boolean isLose = false;
	public void init()
	{
		tableArea.setPreferredSize(new Dimension(TABLE_WIDTH , TABLE_HEIGHT));
		f.add(tableArea);
		//定义键盘监听器
		KeyAdapter keyProcessor = new KeyAdapter()
		{
			public void keyPressed(KeyEvent ke)
			{
				//按下向左、向右键时，球拍水平座标分别减少、增加
				if (ke.getKeyCode() == KeyEvent.VK_LEFT)
				{
					if (racketX > 0)
						racketX -= 10;
				}
				if (ke.getKeyCode() == KeyEvent.VK_RIGHT)
				{
					if (racketX < TABLE_WIDTH - RACKET_WIDTH)
						racketX += 10;
				}
			}
		};
		//为窗口和tableArea对象分别添加键盘监听器
		f.addKeyListener(keyProcessor);
		tableArea.addKeyListener(keyProcessor);
		//定义每0.1秒执行一次的事件监听器。
		ActionListener taskPerformer = new ActionListener() 
		{
			public void actionPerformed(ActionEvent evt)
			{
				//如果小球碰到左边边框
				if (ballX  <= 0 || ballX >= TABLE_WIDTH - BALL_SIZE)
				{
					xSpeed = -xSpeed;
				}
				//如果小球高度超出了球拍位置，且横向不在球拍范围之内，游戏结束。
				if (ballY >= RACKET_Y - BALL_SIZE && 
					(ballX < racketX || ballX > racketX + RACKET_WIDTH))
				{
					timer.stop();
					//设置游戏是否结束的旗标为true。
					isLose = true;
					tableArea.repaint();
				}
				//如果小球位于球拍之内，且到达球拍位置，小球反弹
				else if (ballY  <= 0 || 
					(ballY >= RACKET_Y - BALL_SIZE
						&& ballX > racketX && ballX <= racketX + RACKET_WIDTH))
				{
					ySpeed = -ySpeed;
				}
				//小球座标增加
				ballY += ySpeed;
				ballX += xSpeed;
				tableArea.repaint();
			}
		};
		timer = new Timer(100, taskPerformer);
		timer.start();
		f.pack();
		f.setVisible(true);
	}
	public static void main(String[] args) 
	{
		new PinBall().init();
	}
	class MyCanvas extends Canvas
	{
		//重写Canvas的paint方法，实现绘画
		public void paint(Graphics g)
		{
			//如果游戏已经结束
			if (isLose)
			{
				g.setColor(new Color(255, 0, 0));
				g.setFont(new Font("Times" , Font.BOLD, 30));
				g.drawString("游戏已结束！" , 50 ,200);

			}
			//如果游戏还未结束
			else
			{
				//设置颜色，并绘制小球
				g.setColor(new Color(240, 240, 80));
				g.fillOval(ballX , ballY , BALL_SIZE, BALL_SIZE);
				//设置颜色，并绘制球拍
				g.setColor(new Color(80, 80, 200));
				g.fillRect(racketX , RACKET_Y , RACKET_WIDTH , RACKET_HEIGHT);
			}
		}
	}
}