calling another GUI class

[arnie frenato]

uhm, for example.. I created a class with a button in it.. If I click the button, I would like it to open another gui class that I've created.. How do i do that?

[Craig Wood]

import java.awt.event.*;
import javax.swing.*;
 
public class NewClass implements ActionListener {
    public void actionPerformed(ActionEvent e) {
        // Use the new operator to create an instance of the class
        // you want to instantiate. Save a reference to it and use
        // this reference to call methods in the class.
        AnotherClass anotherClass = new AnotherClass();
        String s = anotherClass.sayHi();
        System.out.println(s);
    }
 
    private JPanel getContent() {
        JButton button = new JButton("create new instance");
        button.addActionListener(this);
        JPanel panel = new JPanel();
        panel.add(button);
        return panel;
    }
 
    public static void main(String[] args) {
        NewClass test = new NewClass();
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.getContentPane().add(test.getContent());
        f.setSize(200,100);
        f.setLocation(200,200);
        f.setVisible(true);
    }
}
 
class AnotherClass {
    public String sayHi() {
        String s = "Is this what you had in mind?";
        int retVal = JOptionPane.showConfirmDialog(null, s, "hi",
                                     JOptionPane.YES_NO_OPTION);
        s = " You selected ";
        switch(retVal) {
            case JOptionPane.YES_OPTION:
                s += "yes";
                break;
            case JOptionPane.NO_OPTION:
                s += "no";
                break;
            default:
                s += "never-mind";
        }
        return s;
    }
}

[arnie frenato]

How about putting another button on the AnotherClass and that button will have an action to perform?

[Davy Kelly]

I dont see why you cant

as long as the button you press has a listener for the action performed, and call the other class' gui method.

davy

[Craig Wood]

import java.awt.Frame;
import java.awt.event.*;
import javax.swing.*;
 
public class NewClass implements ActionListener {
    public void actionPerformed(ActionEvent e) {
        // Use the new operator to create an instance of the class
        // you want to instantiate. Save a reference to it and use
        // this reference to call methods in the class.
        AnotherClass anotherClass = new AnotherClass();
        anotherClass.showDialog();
    }
 
    private JPanel getContent() {
        JButton button = new JButton("create new instance");
        button.addActionListener(this);
        JPanel panel = new JPanel();
        panel.add(button);
        return panel;
    }
 
    public static void main(String[] args) {
        NewClass test = new NewClass();
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.getContentPane().add(test.getContent());
        f.setSize(200,100);
        f.setLocation(200,200);
        f.setVisible(true);
    }
}
 
class AnotherClass implements ActionListener {
    JDialog dialog;
    JLabel label;
 
    public AnotherClass()
    {
        label = new JLabel();
        label.setHorizontalAlignment(JLabel.CENTER);
        JButton button = new JButton("say something");
        button.addActionListener(this);
        JPanel south = new JPanel();
        south.add(button);
        dialog = new JDialog(new Frame(), "AnotherClass dialog");
        dialog.getContentPane().add(label, "First");
        dialog.getContentPane().add(south, "Last");
        dialog.setSize(200,100);
        dialog.setLocation(425, 200);
    }
 
    public void actionPerformed(ActionEvent e)
    {
        System.out.println(e.getActionCommand());
        label.setText(getClass().getName());
    }
 
    public void showDialog() {
        dialog.setVisible(true);
    }
}

[arnie frenato]

Okay, got it. Thanks. One last question. How do I do this - if a button is clicked, it'll create another button, label, or textfield - ?

Thanks again

[Craig Wood]

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
 
public class NewClass implements ActionListener {
    AnotherClass anotherClass = null;
 
    public void actionPerformed(ActionEvent e) {
        // Make sure we can have only a single instance
        // of AnotherClass.
        if(anotherClass == null)
            anotherClass = new AnotherClass();
        anotherClass.showDialog();
    }
 
    private JPanel getContent() {
        JButton button = new JButton("open dialog");
        button.addActionListener(this);
        JPanel panel = new JPanel();
        panel.add(button);
        return panel;
    }
 
    public static void main(String[] args) {
        NewClass test = new NewClass();
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.getContentPane().add(test.getContent());
        f.setSize(200,100);
        f.setLocation(200,200);
        f.setVisible(true);
    }
}
 
class AnotherClass implements ActionListener {
    JDialog dialog;
    JPanel panel;
    GridBagConstraints gbc;
 
    public AnotherClass()
    {
        panel = new JPanel(new GridBagLayout());
        gbc = new GridBagConstraints();
        gbc.insets = new Insets(10,10,10,10);
        gbc.weightx = 1.0;
        gbc.weighty = 1.0;
        JButton button = new JButton("add button");
        button.addActionListener(this);
        JPanel south = new JPanel();
        south.add(button);
        dialog = new JDialog(new Frame(), "AnotherClass dialog");
        dialog.getContentPane().add(new JScrollPane(panel));
        dialog.getContentPane().add(south, "Last");
        dialog.setSize(300,300);
        dialog.setLocation(425, 200);
    }
 
    public void actionPerformed(ActionEvent e)
    {
        int n = panel.getComponentCount();
        gbc.gridwidth = ((n+1)%2 == 0) ? GridBagConstraints.REMAINDER
                                       : GridBagConstraints.RELATIVE;
        panel.add(new JButton("button " + (n+1)), gbc);
        panel.revalidate();
    }
 
    public void showDialog() {
        dialog.setVisible(true);
    }
}

[arnie frenato]

So, how do I add actionlisteners to this buttons?

[Jonathan Janisch]

arnie, that's kind of a silly question.

It's like asking, "Given the following code.."

JButton button1 = new JButton();
button1.addActionListener( ... ) // add the action listener
 
JButton button2 = new JButton();

"... how do you add an actionlistener to button2?"

Maybe this link will help you:

http://java.sun.com/docs/books/tutorial/uiswing/events/index.html

[arnie frenato]

you can probably see that there is no variable assigned to the newly created buttons..

[Jonathan Janisch]

Problem:

Originally posted by arnie frenato:
you can probably see that there is no variable assigned to the newly created buttons..

Solution:

Assign them to a variable.

panel.add(new JButton("button " + (n+1)), gbc);

JButton button = new JButton("button " + (n+1));
button.addActionListener(...);
panel.add(button, gbc);

[arnie frenato]

button.addActionListener(...) what's '...' ?

[Jonathan Janisch]

Programming is about problem solving.

Try to compile it and see what happens. If it gives you an error, try to figure out why. I believe you were using the addActionListener method earlier, maybe that might help.

The (JavaDoc for JButton says that addActionListener expects an ActionListener. '...' doesn't appear to be an Object, let alone an ActionListener. It doesn't even appear to be legal Java code!

public void addActionListener(ActionListener l)Adds an ActionListener to the button. 
 
Parameters:
l - the ActionListener to be added

If you really don't want to learn then I'll tell you the answer

You asked:

So, how do I add actionlisteners to this buttons?

The code I posted showed how to add an ActionListener to your dynamic buttons as you requested. You have to replace '...' with a object whose class implements the ActionListener interface. Craig already posted code that does this.