java AnimationTimer小球移动

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 balls = new ArrayList();
//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
}
}