How do you make another window appear

Ok, here is the situation. I am working on my final project for my java programing class at school and I have run into a bit of a problem. I need to know how to bring up a new "window" when I click something on the main GUI window. For example, I have a menu item that says help, and I have a class in the same package as the main GUI window called help.java. Basically, this help class is a window all in inself in that it extends JFrame and has a main method from which it can open. I've added an action listener to
my help menu item, what should I do in the action performed method to make this help window pop up?

create the JFrame, pack it (if using layout managers -- which you should be doing), and finally call setVisible(true).

Though most often a second window should be a JDialog rather than a new JFrame.

So say I'm trying to display the help class window, should I delete the main method from there and basically put it in the action performed method in my main GUI window?

There's no need to delete the main method, but rather than ask, you're far better of trying and seeing what happens. You won't break anything. ;)

Here is an example:

Code:

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import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class OpenANewWindow {
        public static void main(String[] args) {
                MainWindow frame = new MainWindow();
                frame.showGUI();
        }
}

class MainWindow extends JFrame {
        JButton button;
        JPanel panel;
        NewWindow newWindow = new NewWindow();
       
        public MainWindow() {
                panel = new JPanel();
                newWindow = new NewWindow();
                button = new JButton("New Window");
               
                button.addActionListener(new ActionListener() {
                        public void actionPerformed(ActionEvent e) {
                                newWindow.setVisible(true);
                        }
                });
               
                panel.add(button);
               
                getContentPane().add(panel);
        }
       
        public void showGUI() {
                setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                setSize(300,300);
                setLocation(100,100);
                setVisible(true);
        }
}

class NewWindow extends JFrame {
        public NewWindow() {
                setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                setSize(200,200);
                setLocation(300,300);
                setVisible(false);
        }
}

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But, my advice is to use JOptionPane instead of NewWindow.

Version with JOPtionPane, and class Help.java

class: OpenANewWindow2.java

Code:

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import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JOptionPane;
import javax.swing.JPanel;

import javax.swing.JMenu;
import javax.swing.JMenuItem;
import javax.swing.JMenuBar;

public class OpenANewWindow2 {
        public static void main(String[] args) {
                MainWindow frame = new MainWindow();
                frame.showGUI();
        }
}

class MainWindow extends JFrame {
        JButton button;
        JPanel panel;
        JOptionPane help;
        Help helpPanel = new Help();
       
        JMenuBar menuBar;
        JMenu helpMenu;
        JMenuItem helpItem;
       
        public MainWindow() {
                panel = new JPanel();
               
                menuBar = new JMenuBar();
                helpMenu = new JMenu("Help");
                helpItem = new JMenuItem("Help");
                helpMenu.add(helpItem);
                menuBar.add(helpMenu);
                add(menuBar, BorderLayout.NORTH);
               
               
                helpItem.addActionListener(new ActionListener() {
                        public void actionPerformed(ActionEvent e) {
                                int result = help.showOptionDialog(help.getRootFrame(), helpPanel, "Help", JOptionPane.OK_CANCEL_OPTION,
                                                JOptionPane.QUESTION_MESSAGE, null, null, null);
                        }
                });
               
                getContentPane().add(panel);
        }
       
        public void showGUI() {
                setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                setSize(300,300);
                setLocation(100,100);
                setVisible(true);
        }
}

---

class: Help.java

Code:

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import java.awt.BorderLayout;

import javax.swing.JTextField;
import javax.swing.JTextArea;
import javax.swing.JButton;
import javax.swing.JPanel;

public class Help extends JPanel {
        JTextField textField;
        JTextArea textArea;
       
        public Help() {
                textField = new JTextField(20);
                textArea = new JTextArea(20,6);
                setLayout(new BorderLayout());
                add(textArea, BorderLayout.SOUTH);
                add(textField, BorderLayout.NORTH);
        }
}

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