动态弹球的实现 加入了多线程技术--javaSE游戏准备工作

任务描述:实现了动态弹球的功能，对于有弹球功能的SE游戏奠定了基础。

package 运用线程技术的小球;

import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;//不清楚这个有什么用
import java.util.*;
import javax.swing.*;

public class Bounces {

	public static void main(String[] args) {
		// TODO Auto-generated method stub

		JFrame j = new BounceFrame();

		j.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

		j.setVisible(true);

	}

}

class BallRunnable implements Runnable//线程是Thread(Runnable target) 要使用线程 你必须要实现Runnable接口

{

	private Ball ball;

	private Component component ;

	private static final int step = 300000;

	private static final int delay = 1;

	public BallRunnable(Ball aball,Component acomponent)
	{
		ball = aball;

		component = acomponent;

	}

	public void run()

	{

		try{

			for(int i = 0 ; i <= step ; i++)

					{
				ball.move(component.getBounds());

				component.repaint();//面板不断刷新

				Thread.sleep(delay);

					}
		}catch(InterruptedException e){}

}
}

class Ball
{//实现一个小球类 这个小球包含的方法 包括move()

	private double x = 0;

	private double y = 0 ;

	private double dx = 1;

	private double dy = 1;

    private static final int XSIZE =15;

    private static final int YSIZE =15;

	public void move(Rectangle2D bounds)

	{

		x = x + dx;

		y = y + dy;

		if(x < bounds.getMinX())

		{
			x = bounds.getMinX();

			dx = -dx;

		}

		if(x+XSIZE>=bounds.getMaxX())
		{
			x = bounds.getMaxX()-XSIZE;

			dx = - dx;

		}

        if(y < bounds.getMinY())

		{
			y = bounds.getMinY();

			dy = -dy;

		}

		if(y+YSIZE>=bounds.getMaxY())
		{
			y = bounds.getMaxY()-YSIZE;

			dy = - dy;

		}

	}//关于小球如何移动

	public Ellipse2D getShape()

	{
		return new Ellipse2D.Double(x,y,XSIZE,YSIZE);
	}//返回此时的小球的绘画位置
}

class BallPanel extends JPanel
{
	private ArrayList<Ball> balls = new ArrayList<Ball>();

	//定义了一个集合 这个集合是Ball类型的存储 这个知识点很关键 管存储的作用

	public void add(Ball b)

	{
		balls.add(b);//将Ball的对象加载进去

	}//这就是重写JPanel中的add方法 实现集合加入要更新的小球的重要一步

	public void  paint(Graphics g)
	{

		super.paintComponent(g);

		Graphics2D g2 = (Graphics2D) g;//转换成2D的绘图模式了

		for(Ball b :balls)

		{

			g2.fill(b.getShape());//这时的g2重新绘制小球的全部信息 fill是 专门绘制图形的方法
		}

	}

}

class BounceFrame extends JFrame
{

	private BallPanel panel;

	public BounceFrame()

	{

		setTitle("小球");

		panel = new BallPanel();

		panel.setBackground(Color.BLUE);

		add(panel,BorderLayout.CENTER);

		JPanel buttonPane = new JPanel();

		setBounds(200,200,700,500);

		addButton(buttonPane,"start",new ActionListener(){

			public void actionPerformed(ActionEvent event)

			{

				addBall();
			}
		});

		addButton(buttonPane,"Close",new ActionListener(){

			public void actionPerformed(ActionEvent event)
			{

				System.exit(0);
			}
		});

		add(buttonPane,BorderLayout.SOUTH);
		}

	public void addButton(Container c,String title,ActionListener listener)
	{
		JButton b = new JButton(title);

		c.add(b);

		b.addActionListener(listener);

	}//这个算是变形吧   学习思想

	public void addBall()
	{

			Ball ball = new Ball();

			panel.add(ball);

			Runnable r = new BallRunnable(ball,panel);

			Thread t = new Thread(r);//Thread(Runnable target)

			t.start();//启动线程 实质上是启动的run()方法
	}
}