I’m new to Java graphics, so most of this code is stuff I’ve gathered from the internet and injecting it into my own program. This program is meant to have a red square, controlled by the arrow keys, detect when it collides with a falling blue dot that resets to the top each time it hits the bottom.

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

class Surface extends JPanel implements ActionListener, KeyListener {

    private final int DELAY = 8;
    private Timer timer;
    private Image image;
    private int x, y;
    private final int MOVE_AMOUNT = 5;
    public final int width = 800;
    public final int length = 600;
    private boolean upPressed, downPressed, leftPressed, rightPressed;
    ;

    public Surface() {
        setDoubleBuffered(true);
        initTimer();
        loadImage();
        setFocusable(true);
        requestFocusInWindow();
        addKeyListener(this);
        
        x = 200;
        y = 200;
    }
    
    private Image resizeImage(Image originalImage, int newWidth, int newHeight) {
        return originalImage.getScaledInstance(newWidth, newHeight, Image.SCALE_SMOOTH);
    }
    
    public Rectangle getRedDotBounds() {
        return new Rectangle(x, y, image.getWidth(this), image.getHeight(this));
    }
    
    private void initTimer() {

        timer = new Timer(DELAY, this);
        timer.start();
    }
    
    private void loadImage(){
        ImageIcon ii = new ImageIcon("Basic_red_dot.png");
        if (ii.getImageLoadStatus() == MediaTracker.ERRORED) {
            System.out.println("Image failed to load.");
        }
        Image originalImage =ii.getImage();
     // Resize the image to the desired dimensions
        int newWidth = 75; // Set the desired width
        int newHeight = 75; // Set the desired height
        image = resizeImage(originalImage, newWidth, newHeight);
    }
    
    @Override
    protected void paintComponent(Graphics g){
        super.paintComponent(g);
        g.clearRect(0, 0, getWidth(), getHeight());
        drawImage(g);
    }
    
    private void drawImage(Graphics g){
        g.drawImage(image, x, y, this);
    }
    
    public Timer getTimer() {
        
        return timer;
    }
    
    public void actionPerformed(ActionEvent e) {
        updatePosition();
        repaint();
    }
    
    
    private void updatePosition(){
        if (leftPressed){
            x = Math.max(x-MOVE_AMOUNT, 0);
        }
        if(rightPressed){
            x = Math.min(x + MOVE_AMOUNT, getWidth() - image.getWidth(this));
        }
        if(upPressed){
            y = Math.max(y - MOVE_AMOUNT, 0);
        }
        if(downPressed){
            y = Math.min(y + MOVE_AMOUNT, getHeight() - image.getHeight(this));
        }
    }
    
    
    @Override
    
    public void keyPressed(KeyEvent e){
        int key = e.getKeyCode();
        
        switch (key) {
            case KeyEvent.VK_LEFT:
                leftPressed = true;
                break;
            case KeyEvent.VK_RIGHT:
                rightPressed = true;
                break;
            case KeyEvent.VK_UP:
                upPressed = true;
                break;
            case KeyEvent.VK_DOWN:
                downPressed = true;
                break;
        }
        
        repaint();
    }
    
    
    @Override
    public void keyReleased(KeyEvent e) {
        int key = e.getKeyCode();
        
        switch (key) {
            case KeyEvent.VK_LEFT:
                leftPressed = false;
                break;
            case KeyEvent.VK_RIGHT:
                rightPressed = false;
                break;
            case KeyEvent.VK_UP:
                upPressed = false;
                break;
            case KeyEvent.VK_DOWN:
                downPressed = false;
                break;
        }
        
        
    }

    @Override
    public void keyTyped(KeyEvent e) {
        // Not used, but required by KeyListener
    }

}


class BlueDot extends JPanel implements ActionListener {
    private int x, y;
    private Image image;
    private final int DOT_SIZE = 10;
    private final int FALL_SPEED = 1;
    private Timer timer;
    private int n = 0;
    
    public BlueDot() {
        setDoubleBuffered(true);
        setPreferredSize(new Dimension(500, 500));
        x = (int) (Math.random()*500);
        y = 0;
        loadImage();
        timer = new Timer(10, this);
        timer.start();
    }
    
    private Image resizeImage(Image originalImage, int newWidth, int newHeight) {
        return originalImage.getScaledInstance(newWidth, newHeight, Image.SCALE_SMOOTH);
    }
    
    private void loadImage() {
        ImageIcon ii = new ImageIcon("Basic_blue_dot.png");
        if (ii.getImageLoadStatus() == MediaTracker.ERRORED) {
            System.out.println("Image failed to load.");
        }
        Image originalImage =ii.getImage();
     // Resize the image to the desired dimensions
        int newWidth = 200; // Set the desired width
        int newHeight = 200; // Set the desired height
        image = resizeImage(originalImage, newWidth, newHeight);
    }
    
    public Rectangle getBlueDotBounds() {
        return new Rectangle(x, y, DOT_SIZE, DOT_SIZE);
    }
    
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        g.clearRect(0, 0, getWidth(), getHeight());
        g.drawImage(image, x, y, DOT_SIZE, DOT_SIZE, this);
    }
    
    public void actionPerformed(ActionEvent e){
        
        y += FALL_SPEED;
        if (y > getHeight()) {
            n++;
            System.out.println("reset" + n);
            x = (int) (Math.random() * 500);
            y = 0;
        }
        //repaint();
    }
}


public class MyProgram
{
    public static void main(String[] args){
        SwingUtilities.invokeLater(new Runnable(){
            public void run() {
                JFrame frame = new JFrame();
                frame.setTitle("Image Display");
                frame.setSize(500,500);
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                
                
                Surface surface = new Surface();
                BlueDot blueDot = new BlueDot();
                
                
                frame.setLayout(null);
                
                surface.setBounds(0, 0, 500, 500);
                frame.add(surface);
                
                blueDot.setBounds((int) (Math.random() * 450), 0, 500, 500);
                frame.add(blueDot);
                
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
                
                surface.requestFocusInWindow();
                frame.addWindowListener(new WindowAdapter() {
                    @Override
                    public void windowOpened(WindowEvent e) {
                        surface.requestFocusInWindow();
                    }
                
                });
                
                Timer collisionTimer = new Timer(10, new ActionListener() {
                    public void actionPerformed(ActionEvent e) {
                        Rectangle redBounds = surface.getRedDotBounds();
                        Rectangle blueBounds = blueDot.getBlueDotBounds();
                        
                        if (redBounds.intersects(blueBounds)) {
                            System.out.println("Collision!!!!");
                        }
                    }
                });
                collisionTimer.start();
            }
        });
    }
    
}

The collision detection is a little off, mainly because the red square and the blue dot are constantly flickering. I’ve tried commenting out each of the three repaint statements, but that either results in one of the two elements being invisible, or some other glaring issue. How can I fix the program so this flickering goes away and the collision detection works flawlessly?