package org.net;

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.Ellipse2D;
public class BallFrame extends JFrame{
    JPanel downPanel;
    JButton startButton;
    MyPanel upPanel;
    Ellipse2D.Double d1 ;
    Ellipse2D.Double d2 ;
    long t;
    long begin;
    double x;
    double y;
    public BallFrame(){
        setSize(300,400);
        downPanel = new JPanel();
        startButton = new JButton("start");
        startButton.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent event){
                MyThread t = new MyThread();
                begin = System.currentTimeMillis();
                t.start();
            }
        });
        downPanel.add(startButton);
        add(downPanel,BorderLayout.SOUTH);
        upPanel = new MyPanel();
        d1 = new Ellipse2D.Double(0,0,15,15);
        d2 = new Ellipse2D.Double(0,0,15,15);
        upPanel.addBall(d1,d2);
    }
    public static void main(String[] args) {
        BallFrame f = new BallFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.setVisible(true);
    }
    class MyPanel extends JPanel{
        Ellipse2D.Double d1 ;
        Ellipse2D.Double d2 ;
        public void paintComponent(Graphics g){   //???没有被调用
            super.paintComponent(g);
            System.out.println("===进入paint方法===");
            Graphics2D g2 = (Graphics2D)g;
            g2.fill(d1);
            g2.fill(d2);
        }
        public void addBall(Ellipse2D.Double d1,Ellipse2D.Double d2){
            this.d1 = d1;
            this.d2 = d2;
        }
    }
    class MyThread extends Thread{
        public void run(){
            for(int i=0;i<1000;i++){
                t = (System.currentTimeMillis()-begin)/1000;
                x = 26*t;
                y = 0.5 * 9.8 * Math.pow(t, 2);
                System.out.println(x+":"+y);
                repaint();   //????为什么调用repaint方法不能进入paintComponent方法呢？
                try{
                    Thread.sleep(100);
                }
                catch(Exception e){
                    
                }
            }
        }
    }
}