CODEWITHSUNDEEP
javaswingclass
Natatos
Natatos

Reputation: 145

How can I use another classes variables in a java class?

Ok so I'm trying to get familier with Java, and I've made a simple thing where if you click a button then some text appears. How can I make it so the button and label are created in one class file, and put the code for when the button is clicked in another? Sorry if it sounds like a silly question.

Pastebin code:

package com.nate.derp;

import java.awt.EventQueue;

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JButton;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

public class Derp {

    private JFrame frmHello;


    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    Derp window = new Derp();
                    window.frmHello.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }


    public Derp() {
        initialize();
    }


    public void initialize() {
        frmHello = new JFrame();

        frmHello.setTitle("Hello");
        frmHello.setBounds(100, 100, 225, 160);
        frmHello.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frmHello.getContentPane().setLayout(null);

        final JLabel helloLabel = new JLabel("Hello World!");
        helloLabel.setVisible(false);
        helloLabel.setBounds(40, 89, 145, 16);
        frmHello.getContentPane().add(helloLabel);

        final JButton btnClickMe = new JButton("Click Me!");
        btnClickMe.addMouseListener(new MouseAdapter() {
            public void mouseClicked(MouseEvent e) {
                helloLabel.setVisible(true);
            }
        });


        btnClickMe.setBounds(54, 29, 117, 29);
        frmHello.getContentPane().add(btnClickMe);


    }
}

Upvotes: 2

Views: 228

Answers (1)

Andrew Fielden
Andrew Fielden

Reputation: 3899

You can do this by creating a JButton and adding an ActionListener, which can be implemented by another class.

So you first create the JButton:

Jbutton button = new JButton("hello");

Then add the Actionlistener:

button.addActionListener(new MyListener());

Where MyListener is your implementation class

class MyListener implements ActionListener {
    public void actionPerformed(ActionEvent e) {
       ...
    }
}

Upvotes: 1

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