import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;

public class forLP extends JDialog implements ActionListener{
    
    JPanel panel_total ;
    JPanel panel_center ;
    JPanel panel_north;
    
    public static void main(String[] args) throws InterruptedException{
        new forLP().doIt();
    }
    
    public forLP(){
        super();
    }
    
    public void doIt() throws InterruptedException {
        panel_total = new JPanel(new BorderLayout());
        
        panel_north = getNorthPanel();
        panel_total.add(panel_north,BorderLayout.NORTH);
        
        panel_center = new JPanel();
        panel_total.add(panel_center,BorderLayout.CENTER);
        
        this.add(panel_total);
        this.setSize(500, 500);
        this.setVisible(true);
    }

    private void setCenterPanel() throws InterruptedException {
        
        int x = 250 ; 
        int y = 250 ;
        int flag = 1 ;
        
        panel_center.setLayout(null);
        JButton jb = getButton(x,y);
        jb.setBackground(getRandomColor());
        panel_center.add(jb);
        panel_center.updateUI();

        /**
         * 新建两个线程,每割1秒刷新出一个按钮
         * 但是为什么总是到第二秒的时候两个按钮一起出来呢。。
         */

        SwingUtilities.invokeLater(new Runnable(){
            public void run() {
                try {
                    Thread.sleep(1000);
                    JButton jb = getButton(250, 300);
                    panel_center.add(jb);
                    panel_center.repaint();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        });
        
        SwingUtilities.invokeLater(new Runnable(){
            public void run() {
                try {
                    Thread.sleep(2000);
                    JButton jb = getButton(350, 300);
                    panel_center.add(jb);
                    panel_center.repaint();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        });
        
//        for( int i = 1 ; i < 2 ; i ++){
//            if( i%2 == 1){
//                for(int j = 0 ; j < i ; j ++){
//                    y = y + 20;
//                    addButton(x,y,flag);
//                    flag ++ ;
//                }
//                for(int k = 0 ; k < i ; k ++){
//                    x = x + 20 ;
//                    addButton(x,y,flag);
//                    flag ++ ;
//                }
//            }else {
//                for(int j = 0 ; j < i ; j ++){
//                    y = y - 20;
//                    addButton(x,y,flag);
//                    flag ++ ;
//                }
//                for(int k = 0 ; k < i ; k ++){
//                    x = x - 20 ;
//                    addButton(x,y,flag);
//                    flag ++ ;
//                }
//            }                
//        }
    }
    
    public Color getRandomColor(){
        Color color = new Color(
        (new Double(Math.random() * 128)).intValue() + 128,   
        (new Double(Math.random() * 128)).intValue() + 128,   
        (new Double(Math.random() * 128)).intValue() + 128);
        return color ;
    }
    
    

    private void addButton(final int x, final int y, final int flag) {
        SwingUtilities.invokeLater(new Runnable(){
            public void run() {
                try {
                    Thread.sleep(1000*flag);
                    System.out.println("执行第"+flag+" 坐标："+x+" " +y);
                    JButton jb = getButton(x, y);
                    panel_center.add(jb);
                    panel_center.repaint();
                    panel_center.updateUI();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        });
    }

    private JButton getButton(int x,int y) {
        JButton jb = new JButton();
        jb.setPreferredSize(new Dimension(10,10));
        jb.setBounds(x, y, 10, 10);
        jb.setBackground(getRandomColor());
        jb.setVisible(true);
        return jb;
    }

    private JPanel getNorthPanel() {
        JPanel panel = new JPanel(new FlowLayout(FlowLayout.LEFT));
        JButton btn_1 = new JButton("点我");
        btn_1.addActionListener(this);
        panel.add(btn_1);
        return panel;
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        try {
            setCenterPanel();
        } catch (InterruptedException e1) {
            e1.printStackTrace();
        }
        
    }

}