How do i add another button in JButton

Question

I have 1 button i. but i need another. i added another JFrame and made a new class making the button. whenever i do

frame.add(new TestButton());

it never works. i already have

frame.add(new TestPanel());

which works. but its the only working one. here is my TestButton code

package App.Gui.Buttons;

import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JPanel;

import App.Gui.Event.ExitEvent;

public class TestButton extends JPanel {
    public TestButton() {
        setLayout(new GridBagLayout());
        JButton button = new JButton();
        button.setBackground(new Color(0, 0, 0, 0));
        button.setForeground(new Color(0, 0, 0, 0));
        button.setBorderPainted(false);
        button.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                ExitEvent.exit();
            }
        });

        GridBagConstraints gbc = new GridBagConstraints();
        gbc.anchor = GridBagConstraints.CENTER;
        gbc.gridx = 0;
        gbc.gridy = 0;
        gbc.weightx = 1;
        gbc.insets = new Insets(20, 50, 20, 50);
        add(button, gbc);

        gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.gridy = 0;
        gbc.weightx = 1;
        gbc.weighty = 1;
        gbc.fill = GridBagConstraints.BOTH;

        JPanel contentPane = new JPanel(new GridBagLayout());
        contentPane.setBackground(Color.GREEN);
        contentPane.add(new JLabel("Books app"));
        add(contentPane, gbc);
    }

    @Override
    public Dimension getPreferredSize() {
        return new Dimension(1200, 750);
    }

    public static void addButton() {
        new TestButton();
        
    }
    
}

i need to add another button to do more stuff like you would need in a software. but it either never starts or, it bugs the buttons. pls help.

Answer 1

A JPanel can't be shown in of itself. It needs to be added to a container hierarchy which is backed by a window based class, like JFrame.

This is a pretty basic concept, which suggests that you might be better off spending some time going through Creating a GUI With Swing, especially How to Make Frames (Main Windows)

import java.awt.EventQueue;
import javax.swing.JFrame;

public class Main {

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

    public Main() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                JFrame frame = new JFrame();
                frame.add(new TestButton());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

}

Also, JFrame uses a BorderLayout by default, so you'll only be able to present a single component at each of it's five available positions.

So, if instead, you used a GridLayout, you could get multiple instances of TestButton on the window at the same time, for example

import java.awt.EventQueue;
import java.awt.GridLayout;
import javax.swing.JFrame;

public class Main {

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

    public Main() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                JFrame frame = new JFrame();
                frame.setLayout(new GridLayout(2, 1));
                frame.add(new TestButton());
                frame.add(new TestButton());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

}

Now, Swing components also don't support alpha based colors, they are either opaque or they are not (no translucency - you can fake it, but that's beyond the scope)

So, I'd modify you code to look more like...

JButton button = new JButton();
//button.setBackground(new Color(0, 0, 0, 0));
//button.setForeground(new Color(0, 0, 0, 0));
button.setBorderPainted(false);
button.setOpaque(false);
button.setContentAreaFilled(false);

Also, good luck on been able to click that button by the way

Full code...

import java.awt.Color;
import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JPanel;

public class TestButton extends JPanel {

    public TestButton() {
        setLayout(new GridBagLayout());
        JButton button = new JButton();
        //        button.setBackground(new Color(0, 0, 0, 0));
        //        button.setForeground(new Color(0, 0, 0, 0));
        button.setBorderPainted(false);
        button.setOpaque(false);
        button.setContentAreaFilled(false);
        button.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                //ExitEvent.exit();
            }
        });
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.anchor = GridBagConstraints.CENTER;
        gbc.gridx = 0;
        gbc.gridy = 0;
        gbc.weightx = 1;
        gbc.insets = new Insets(20, 50, 20, 50);
        add(button, gbc);

        gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.gridy = 0;
        gbc.weightx = 1;
        gbc.weighty = 1;
        gbc.fill = GridBagConstraints.BOTH;
        JPanel contentPane = new JPanel(new GridBagLayout());
        contentPane.setBackground(Color.GREEN);
        contentPane.add(new JLabel("Books app"));
        add(contentPane, gbc);
    } 

    @Override
    public Dimension getPreferredSize() {
        return new Dimension(1200, 750);
    }

}

There are also issues with updating a realised window (adding/removing components once the window is visible on the screen). Swing is lazy and you are required to request a layout and paint pass on the container you've modified (invalidate and repaint).

But you might find CardLayout more suitable to your needs instead - but since we don't have a runnable example, it's hard to know