package Star;
import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JPanel;
public class Star extends JPanel{
  /**
   * 基本的行星類
   */
  private static final long serialVersionUID = 1L;
  int x,y;
  int width,height;
  public Star() {
    width = 10;
    height = 10;
  }
  public Star(int x, int y){
    this.x = x;
    this.y = y;
    width = 10;
    height = 10;
  }
  public void draw(Graphics g){
    g.setColor(Color.blue);
    g.fillOval(x, y, width, height);
  }
  protected void paintComponent(Graphics g){
    super.paintComponent(g);
    g.fillOval(x, y, width, height);
  }
}

package Star;
import java.awt.Color;
import java.awt.Graphics;
public class Stars extends Star{
  /**
   * 運(yùn)動的行星
   */
  private static final long serialVersionUID = 1L;
  double alfa ;
  double speed ;
  Star center;
  int Long ; //長軸
  int Short;//短軸
  public Stars(int Px,int Py,Star center){
    super(Px,Py);
    this.center = center;
    Long = (Px - center.x)*2;
    Short = (Py - center.y)*2;
    this.setOpaque(true);
//   move();
    alfa = 0;
    speed = 0.001;
  }
  protected void paintComponent(Graphics g){
    super.paintComponent(g);
    center.draw(g);//畫出中心點
    move();
    g.setColor(Color.GREEN);
    g.drawOval(center.x-Long/2, center.y-Short/2, Long, Short);
  }
  public void move(){
    x = center.x + (int)(Long/2*Math.cos(alfa));
    y = center.y + (int)(Short/2*Math.sin(alfa));
    //沿橢圓軌跡運(yùn)行
    alfa += speed;
    //角度不斷變化
  }
  class PThread extends Thread{
  //重畫線程類
    private boolean suspend = true;
    private String control = "";
    public void run(){
      while(true){
        synchronized (control) {
          if(suspend){
            //move();
            repaint();
          }
        }
      }
    }
    public void setsuspend(boolean s){
      //設(shè)置線程暫停方法
       if (!suspend) {
         synchronized (control) {
           control.notifyAll();
         }
       }
      this.suspend = s;
    }
  }
  public PThread pt = new PThread();
  public void start(){
    pt.setsuspend(true);
    pt.start();
  }
  public void pause(){
    pt.setsuspend(false);
  }
  public void accelerate(){
    //加速的方法
    if(speed > 0){
      //角度每次加速0.0002
      speed += 0.0002;
    }
    else
      speed = 0.001;
  }
  public void decelerate(){
    //減速的方法
    if(speed > 0){
      speed -= 0.0002;
      //角度每次減速0.0002
    }
    //若減速到0，則不能繼續(xù)減速，另速度為0，停止運(yùn)動
    else speed = 0;
  }
}

package Star;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JLayeredPane;
import javax.swing.JPanel;
public class StarFrame extends JFrame{
  /**
   *行星模擬啟動面板
   */
  private static final long serialVersionUID = 1L;
  Star center = new Star(300,200);//定義中心行星
  Stars p1 = new Stars(300+230,200+130,center);//環(huán)繞中心的行星
  Stars p2 = new Stars(300+230+20,200+130+20,p1);
  JButton jb1 = new JButton("start");
  JButton jb2 = new JButton("pause");
  JButton jb3 = new JButton("accelerate");
  JButton jb4 = new JButton("decelerate");
  ImageIcon image=new ImageIcon("timg.jpg");//背景圖，利用相對路徑定義
  JLayeredPane layeredPane; //定義一個層次面板，用于放置背景圖片
  JPanel jp;
  JLabel jl;
  public StarFrame(){
    //為p1設(shè)置位置，與大小
    p1.setBounds(40,40,600,400);
//   p2.setBounds(40,40,600,400);
    //定義背景圖，將背景圖放于JLabel中，將JLabel放于JPanel中
    layeredPane = new JLayeredPane();
    jp = new JPanel();
    jp.setBounds(0,0,image.getIconWidth(),image.getIconHeight());
    jl=new JLabel(image);
    jp.add(jl);
    //將jp放到最底層。
    layeredPane.add(jp,JLayeredPane.DEFAULT_LAYER);
    //將jb放到高一層的地方
    layeredPane.add(p1,JLayeredPane.MODAL_LAYER);
//   layeredPane.add(p2,JLayeredPane.MODAL_LAYER);
    layeredPane.add(getPanel(),JLayeredPane.MODAL_LAYER);
    layeredPane.add(getLabel(),JLayeredPane.MODAL_LAYER);
    //分別為jb1、jb2、jb3、jb4設(shè)置相關(guān)動作
    jb1.addActionListener(new ActionListener(){
      public void actionPerformed(ActionEvent e) {
        // TODO Auto-generated method stub
        p1.start();
      }
    }
    );
    jb2.addActionListener(new ActionListener(){
      public void actionPerformed(ActionEvent e) {
        // TODO Auto-generated method stub
        p1.pause();
      }
    });
    jb3.addActionListener(new ActionListener(){
      public void actionPerformed(ActionEvent e) {
        // TODO Auto-generated method stub
        p1.accelerate();
      }
    });
    jb4.addActionListener(new ActionListener(){
      public void actionPerformed(ActionEvent e) {
        // TODO Auto-generated method stub
        p1.decelerate();
      }
    });
    this.setLayeredPane(layeredPane);
    this.setTitle("Star");
    this.setBounds(100,100,1000, 600);
    this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    this.setVisible(true);
  }
  private JPanel getPanel(){
    //返回定義的四個按鈕
    JPanel jp = new JPanel();
    jp.add(jb1);
    jp.add(jb2);
    jp.add(jb3);
    jp.add(jb4);
    jp.setBounds(750,450,200,70);
    return jp;
  }
  private JPanel getLabel(){
    //返回文字描述
    JLabel jl = new JLabel("行星模擬");
    jl.setForeground(Color.RED);//設(shè)置字體顏色
    jl.setFont(new Font("Dialog",0,20));//設(shè)置字體
    JPanel jp = new JPanel();
    jp.add(jl,BorderLayout.CENTER);
    jp.setBounds(800,0,150,40);
    return jp;
  }
  public static void main(String[] args) {
    @SuppressWarnings("unused")
    StarFrame f = new StarFrame();
  }
}