package chapter11;

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.Random;


public class PinBallGameDemo1 {
    //桌面的宽度、高度
    int TABLE_WIDTH=300;
    int TABLE_HEIGHT=400;
    //球拍的垂直位置
    int RACKET_Y=340;
    //球拍的高和宽
    int RACKET_HEIGHT=20;
    int RACKET_WIDTH=60;

    //小球大小
    int BALL_SIZE=16;

    Frame frame=new Frame("弹球游戏1.0");
    Random rand=new Random();

    //小球纵向运行速度
    int ySpeed=10;
    //返回一个-0.5-0.5的比率，用于控制小球的运动方向
    double xyRate=rand.nextDouble()-0.5;

    //小球横向运行速度
    int xSpeed=(int)(ySpeed*xyRate*2);
    //小球的坐标
    int ballY=rand.nextInt(10)+20;
    int ballX=rand.nextInt(200)+20;

    //球拍的水平位置
    int racketX=rand.nextInt(200);

    MyCanvas3 myCanvas=new MyCanvas3();
    javax.swing.Timer timer;
    //游戏是否结束的标志
    boolean isLose=false;

    //难度更改按钮
    JButton easyButton=new JButton("简单");
    JButton midButton=new JButton("一般");
    JButton difficultButton=new JButton("困难");
    int easy=0;
    int mid=2;
    int difficult=5;

    Panel p=new Panel();



    public void init(){
        ActionListener easyButtonListener=e->{
            ySpeed+=easy;
            xSpeed+=easy;
        };
        ActionListener midButtonListener=e->{
            ySpeed+=mid;
            xSpeed+=mid;
        };
        ActionListener difficultButtonListener=e->{
            ySpeed+=difficult;
            xSpeed+=difficult;
        };
        easyButton.addActionListener(easyButtonListener);
        midButton.addActionListener(midButtonListener);
        difficultButton.addActionListener(difficultButtonListener);


        frame.addWindowListener(new WindowAdapter() {
            @Override
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
        //设置桌面区域的最佳大小
        myCanvas.setPreferredSize(new Dimension(TABLE_WIDTH,TABLE_HEIGHT));

        frame.add(myCanvas);
        p.add(easyButton);
        p.add(midButton);
        p.add(difficultButton);
        frame.add(p,BorderLayout.SOUTH);


        frame.setResizable(false);
        //设置键盘监听器
        var keyProcessor=new KeyAdapter(){
            public void keyPressed(KeyEvent ke){
                //按下向左、向右键时，球拍水平坐标分别减少、增加
                if(ke.getKeyCode()==KeyEvent.VK_LEFT){
                    if(racketX>0){
                        racketX-=10;
                    }

                }
                if(ke.getKeyCode()==KeyEvent.VK_RIGHT){
                    if(racketX<TABLE_WIDTH-RACKET_WIDTH){
                        racketX+=10;
                    }
                }
            }
        };
        //窗口和画板添加监听器
        frame.addKeyListener(keyProcessor);
        myCanvas.addKeyListener(keyProcessor);

        //定义每隔 0.1秒 执行一次的事件监听器
        ActionListener taskPerformer= evt->
        {
          //如果小球碰到左右边框
          if(ballX<=0 || ballX>=TABLE_WIDTH-BALL_SIZE){
              xSpeed=-xSpeed;
          }
          //如果小球高度超过了球拍位置，并且横向不在球拍范围之内，游戏结束
            if(ballY>=RACKET_Y-BALL_SIZE && (ballX<racketX || ballX>racketX+RACKET_WIDTH)){
                timer.stop();
                //设置游戏是非结束的标志性为true
                isLose=true;
                myCanvas.repaint();
            }
            //如果小球位于球拍之内，且到达球拍位置，小球反弹
            else if (ballY<=0 || (ballY>=RACKET_Y-BALL_SIZE && ballX>racketX && ballX<=racketX+RACKET_WIDTH)){
                ySpeed=-ySpeed;
            }
            //小球坐标增加
            ballY+=ySpeed;
            ballX+=xSpeed;
            myCanvas.repaint();
        };
        timer=new Timer(100,taskPerformer);
        timer.start();

        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);

    }


    public static void main(String[] args) {
        new PinBallGameDemo1().init();
    }


    class MyCanvas3 extends Canvas{
        public void paint(Graphics g){
            //如果游戏已经结束
            if(isLose){
                g.setColor(new Color(255,0,0));
                g.setFont(new Font("Times",Font.BOLD,30));
                g.drawString("游戏已经结束!",50,200);
            }else {//游戏未结束
                //设置颜色，绘制小球
                g.setColor(new Color(240,240,80));
                g.fillOval(ballX,ballY,BALL_SIZE,BALL_SIZE);
//                g.fillArc(ballX,ballY,BALL_SIZE,BALL_SIZE,0,360);

                //设置颜色，绘制球拍
                g.setColor(new Color(80,80,200));
                g.fillRect(racketX,RACKET_Y,RACKET_WIDTH,RACKET_HEIGHT);
            }
        }
    }

}

游戏开始

游戏失败结束