73_2dAnimation

<Main.java>
public class Main {
    public static void main(String[] args){

        new MyFram();
    }
}

<MyFram.java>
import javax.swing.*;
import java.awt.*;

public class MyFram extends JFrame {
    MyPanel panel;
    MyFram(){
        panel = new MyPanel();
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.add(panel);
        this.pack();
        this.setSize(500,500);
        this.setLocationRelativeTo(null);
        this.setVisible(true);
    }

}

<MyPanel.java>
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class MyPanel extends JPanel implements ActionListener {

    final int PANEL_WIDTH = 500;
    final int PANEL_HEIGHT = 500;
    Image search;
    Image backgroundImage;
    Timer timer;
    int xVelocity = 2; //if 1 move in top left to bottom right, if 2 move like >
    int yVelocity = 1;
    int x = 0;
    int y = 0;
    
    MyPanel(){
        this.setPreferredSize((new Dimension(PANEL_WIDTH,PANEL_HEIGHT)));
        this.setBackground(Color.black);//Background image will replace
        search = new ImageIcon("smile.png").getImage();
        backgroundImage = new ImageIcon("pizza.png").getImage();
        timer = new Timer(100,this);//delay, listener
        timer.start();
    }
    public void paint(Graphics g){
        super.paint(g);//paint background
        Graphics2D g2D = (Graphics2D) g;
        g2D.drawImage(backgroundImage,0,0,null);
        g2D.drawImage(search,x,y,null);//img, x, y, null
    }
    @Override
    public void actionPerformed(ActionEvent e) {
        //Move horizontally back & forth
        if(x>=PANEL_WIDTH - search.getWidth(null )|| x<0){
            xVelocity = xVelocity * -1;
        }
        x = x + xVelocity;
        repaint();//or else resize window to repaint

        //To move vertically
        if(y>=PANEL_WIDTH - search.getWidth(null) || y<0){
            yVelocity = yVelocity * -1;
        }
        y = y + yVelocity;
    }
        //Have both vertical & horizontal --> diagonal
}