How do I put graphics on a JPanel?

graphics, java, jframe, jpanel, swing

Solution

The custom component was 0x0 px.

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

public class Catch {

    public class MyGraphics extends JComponent {

        private static final long serialVersionUID = 1L;

        MyGraphics() {
            setPreferredSize(new Dimension(500, 100));
        }

        @Override
        public void paintComponent(Graphics g) {
            super.paintComponent(g);
            g.fillRect(200, 62, 30, 10);
        }
    }

    public void createGUI() {
        final JFrame frame = new JFrame();
        JPanel panel = new JPanel();
        panel.add(new MyGraphics());
        frame.add(panel);
        frame.pack();
        frame.setVisible(true);
        frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                Catch GUI = new Catch();
                GUI.createGUI();
            }
        });
    }
}

Problem

I am having a problem adding graphics to a JPanel. If I change the line from panel.add(new graphics()); to frame.add(new graphics()); and do not add the JPanel to the JFrame, the black rectangle appears on the JFrame. I just cannot get the black rectangle to appear on the JPannel and was wondering if someone could help me with this. ``` import java.awt.*; import java.awt.event.*; import javax.swing.*; public class Catch{ public class graphics extends JComponent{ public void paintComponent(Graphics g){ super.paintComponents(g); g.fillRect(200, 62, 30, 10); } } public void createGUI(){ final JFrame frame = new JFrame(); JPanel panel = new JPanel(); frame.setSize(500,500); frame.addMouseListener(new MouseAdapter(){ public void mouseClicked(MouseEvent e) { System.out.println(e.getPoint().getX()); System.out.println(e.getPoint().getY()); } }); panel.add(new graphics()); frame.add(panel); frame.setVisible(true); frame.setDefaultCloseOperation(frame.DISPOSE_ON_CLOSE); } public static void main(String[] args){ Catch GUI= new Catch(); GUI.createGUI(); } } ```

Original source