import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.Random;

public class GameField extends JPanel implements ActionListener, Runnable {

    private Timer timer = new Timer(20, this); // частота обновления кадров (отрисовки) , запускает фукцию экшн перформед каждые 20 мс

    private Image img = new ImageIcon("Images/background.jpg").getImage();

    private Player player = new Player();

    private Thread enemiesRespawn = new Thread(this);

    private java.util.List<Enemy> enemies = new ArrayList<Enemy>();


    public GameField() throws IOException {
        timer.start();
        enemiesRespawn.start();
        addKeyListener(new MyKeyAdapter());
        setFocusable(true);
    }

    public class MyKeyAdapter extends KeyAdapter {

        public void keyPressed(KeyEvent e){

            player.keyPressed(e);
        }

        public void keyReleased(KeyEvent e){

            player.keyReleased(e);
        }
    }

    public void paint(Graphics graphics) {

        graphics = (Graphics2D) graphics;

        graphics.drawImage(img, 0, player.layer1, null);
        graphics.drawImage(img, 0, player.layer2, null);

        graphics.drawImage(player.img, player.x, player.y, null);

        int distance = player.getDistance();
        graphics.setColor(Color.ORANGE);
        Font font = new Font("Arial", Font.BOLD, 20);
        graphics.setFont(font);
        graphics.drawString("Score: " + distance, 190, 35);

        Iterator<Enemy> i = enemies.iterator();
        while (i.hasNext()) {
            Enemy enemy = i.next();
            if (enemy.getX() >= 1200 || enemy.getX() <= -1200) {
                i.remove(); // удаляем элемент из коллекции
            } else {
                enemy.move();
                graphics.drawImage(enemy.img, enemy.getX(), enemy.getY(), null);
            }
        }
    }

    // вызывается каждый раз, когда что-либо происходит
    @Override
    public void actionPerformed(ActionEvent e) {
        player.move();
        repaint();
        testCollision();
    }

    private void testCollision() {

        Iterator<Enemy> i = enemies.iterator();
        while (i.hasNext()) {
            Enemy enemy = i.next();
            if (player.getRectangle().intersects(enemy.getRectangle())) {
                JOptionPane.showMessageDialog(null, "YOU LOSE!!!!" + "\nYOUR SCORE IS " + player.getDistance());
                System.exit(1);
            }
        }
    }


    @Override
    public void run() {
        while (true) { // бесконечное создание врагов
            Random random = new Random(); // случайная задержка
            try {
                Thread.sleep(random.nextInt(2000)); // ститический метод, "заснем" на случайный промежуток времени

                enemies.add(new Enemy(random.nextInt(400), 0, random.nextInt(15)+5));
            } catch (InterruptedException | IOException e) {
                e.printStackTrace();
            }
        }
    }
}



import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.event.KeyEvent;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

public class Player {

    BufferedImage img = ImageIO.read(new File("Images/rocket_2.png"));

    private final int width = img.getWidth();
    private final int hight = img.getHeight();
    private static final int maxRight = 400;
    private static final int maxLeft = 2;

    private static int speed = 6;
    private int direction = 0;
    private int acceleration = 0;
    private int distance = 0;
    private int checkPoint = 500;
    private int n = 1;

    int layer1 = 0;
    int layer2 = -1334;

    int x = 190;
    int y = 480;

    public Player() throws IOException {

    }

    public Rectangle getRectangle() {
        return new Rectangle(x, y, width-40, hight-35);
    }

    public void move() {

        distance += speed;

        if (distance >= checkPoint) {

            checkPoint += (1000 * n);
            n += 1;
            acceleration += 1;
            speed += acceleration;
        }

        x += direction;
        if (x <= maxLeft) {
            x = maxLeft;
        }
        if (x >= maxRight) {
            x = maxRight;
        }


        if (layer2 + speed >= 0) {
            layer1 = layer2 + speed;
            layer2 = layer1 - 1334;
        } else {
            layer1 += speed;
            layer2 += speed;
        }
    }

    public void keyPressed(KeyEvent e) {

        int key = e.getKeyCode();

        if (key == KeyEvent.VK_RIGHT) {
            direction = 5;

        }

        if (key == KeyEvent.VK_LEFT) {
            direction = -5;
        }

    }

    public void keyReleased(KeyEvent e) {

        int key = e.getKeyCode();

        if (key == KeyEvent.VK_RIGHT | key == KeyEvent.VK_LEFT) {
            direction = 0;
        }
    }

    public int getWidth() {
        return width;
    }

    public int getHight() {
        return hight;
    }

    public static int getSpeed() {
        return speed;
    }

    public int getDistance() {
        return distance;
    }
}



import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

public class Enemy {

    BufferedImage img = ImageIO.read(new File("/Users/test/Documents/Game/MyGame/Images/enemy.png"));

    private final int width = img.getWidth();
    private final int hight = img.getHeight();

    private int x;
    private int y;
    private int speed;

    public Enemy(int x, int y, int speed) throws IOException {
        this.x = x;
        this.y = y;
        this.speed = speed;
    }

    public Rectangle getRectangle() {
        return new Rectangle(x, y, width-35, hight-30);
    }

    public void move() {
        y = y + Player.getSpeed() + speed;
    }

    public int getX() {
        return x;
    }

    public int getY() {
        return y;
    }


}



import javax.swing.*;
import java.awt.*;

public class DrawScreenSaver extends JPanel {

    Image img = new ImageIcon("/Users/test/Documents/Game/MyGame/Images/spaceX.jpg").getImage();

    @Override
    protected void paintComponent(Graphics graphics) {
        super.paintComponent(graphics);
        graphics = (Graphics2D) graphics;
        graphics.drawImage(img, 0, 0, null);
    }
}

import javax.imageio.ImageIO;
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

public class Main {

    static JFrame frame = new JFrame("SPACE BATTLE");
    static JButton button = new JButton("PLAY");
    static JPanel panel = new JPanel();
    static DrawScreenSaver screen = new DrawScreenSaver();
    static GameField gameField;

    static {
        try {
            gameField = new GameField();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {
    // write your code here

        frame.setSize(500, 700);
        button.setPreferredSize(new Dimension(200, 100));
        button.setBorderPainted(false);
        button.setFont(new Font("Arial", Font.BOLD, 40));
        button.setForeground(new Color(255, 188, 59));

        button.addActionListener(new Handler());
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        frame.setLocationRelativeTo(null);

        frame.getContentPane().add(screen);
        screen.setLayout(new GridBagLayout());
        screen.add(button);

        frame.setVisible(true);
    }

    public static class Handler implements ActionListener {

        @Override
        public void actionPerformed(ActionEvent e) {
            if (e.getSource() == button) {

//                frame.getContentPane().remove(reader);


                /*frame.getContentPane().remove(panel);
                frame.getContentPane().add(reader);*/

                frame.getContentPane().remove(screen);
                frame.getContentPane().add(gameField);
                frame.setVisible(true);
            }
        }
    }
}