import javax.swing.JFrame;

import javax.swing.JLabel;

import javax.swing.JButton;

import javax.swing.JTextField;

import java.awt.Container;

import java.awt.GridLayout;

import java.awt.event.ActionListener;

import java.awt.event.ActionEvent;

public class TextAdder extends JFrame implements ActionListener

{

private JLabel labelPlus, labelSum;

private JButton buttonEquals;

private JTextField text1, text2;

// _4______ + _________ = [ ]

public TextAdder()

{

//JFrame Stuff

setSize(500,100);

setTitle("Text Adder");

setDefaultCloseOperation(EXIT_ON_CLOSE);

//instantiate my JComponents

labelPlus = new JLabel("+", JLabel.CENTER);//overloaded constructor for label using alignment

labelSum = new JLabel ("", JLabel.RIGHT);//we can align center or right (default is left)

buttonEquals = new JButton ("=");

text1 = new JTextField("4");//overloaded constructor with pre-data

text2 = new JTextField();//default constructor with no data

//set up pane and layout

Container pane = this.getContentPane();

pane.setLayout(new GridLayout(1,5));

//added elements to the layout

pane.add(text1);

pane.add(labelPlus);

pane.add(text2);

pane.add(buttonEquals);

pane.add(labelSum);

//set up the action listener/button

buttonEquals.addActionListener(this);

//make it all visible

setVisible (true);

}

public void actionPerformed (ActionEvent e)

{

if (e.getActionCommand().equals("="))

{

int num1 = Integer.parseInt(text1.getText());

int num2 = Integer.parseInt(text2.getText());

int sum = num1 + num2;

labelSum.setText(String.valueOf(sum));

}

}

public static void main (String[] args)

{

TextAdder t = new TextAdder();

}

}