import javax.swing.*;
import java.awt.*;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.util.TimerTask;

public class GUIApp extends JFrame {
    private Draw draw;
    private int x1;
    private int x2;
    private int y1;
    private int y2;

    private int linex1,liney1, linex2,liney2;

    private boolean way;

    private java.util.Timer timer;

    public GUIApp() throws HeadlessException {
        setSize(500,500);
        setLocationRelativeTo(null);

        draw = new Draw();
        add(draw);

        timer = new java.util.Timer();

        x1 = 100;
        x2 = 100;
        y1 = 100;
        y2 = 200;

        linex1 = 50;
        liney1 = 400;
        linex2 = 400;
        liney2 = 400;
        way = true;
        timer.schedule(new TimerTask() {
            @Override
            public void run() {
                isCollision();
                if (way) {
                    y2 = y2 + 25;
                } else {
                    x2 = x2 + 25;
                    y2 = y2 - 25;
                }

                repaint();
            }
        },3500,1500);

        addKeyListener(new KeyListener() {
            @Override
            public void keyTyped(KeyEvent e) {

            }

            @Override
            public void keyPressed(KeyEvent e) {
                if (e.getKeyCode() == KeyEvent.VK_DOWN) {
                    y2 = y2 + 25;
                    repaint();
                }
            }

            @Override
            public void keyReleased(KeyEvent e) {

            }
        });

        setVisible(true);
    }

    private void isCollision () {
        if(y2>= liney2) {
            way = false;
        }
    }

    class Draw extends JPanel {

        @Override
        protected void paintComponent(Graphics g) {
            g.setColor(Color.RED);
            g.drawLine(x1,y1,x2,y2);
            g.drawLine(linex1, liney1, linex2,liney2);
        }
    }

    public static void main(String[] args) {
        new GUIApp();
    }
}