Using Java, modify the following \'MessageBoxes\' application so it uses a singl
ID: 3920080 • Letter: U
Question
Using Java, modify the following 'MessageBoxes' application so it uses a single action listener for each button. This will require you to separate the single action listener logic into multiple listeners, one for each button. Then modify the code to provide additional options to two or more buttons. For instance, you can change "3 Vals" to "5 Vals" or add colors to the color choice option. [Hint: Don't feel obligated to add the listeners to the buttons in a loop, as is done here. As a matter of fact, the buttons do not have to be in an array of JButton type. That works fine when you're assigning the same listener to all buttons, but does not necessarily make sense once you are making separate listeners for each button.]
/*
* The source code for this assignment started with
* a sample from "Thinking in Java" 3rd ed. page 825
* by Bruce Eckel. I have finished adding the rest of the action logic.
*
* Try to implement one new action listener at a time
* do not try to do all of them and then compile
*/
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class MessageBoxes{
private JButton[] b = {
new JButton("Alert"),
new JButton("Yes/No"),
new JButton("Color"),
new JButton("Input"),
new JButton("3 Vals"),
};
private JTextField txt = new JTextField(15);
private JFrame frame;
private ActionListener al = new ActionListener(){
public void actionPerformed(ActionEvent e){
String id = ((JButton)e.getSource()).getText();
if(id.equals("Alert")){
JOptionPane.showMessageDialog(null,
"There's a bug on you!", "Hey!",
JOptionPane.ERROR_MESSAGE);
}
else if(id.equals("Yes/No")){
int val = JOptionPane.showConfirmDialog(null,
"or no", "Chose yes",
JOptionPane.YES_NO_OPTION);
if(val != JOptionPane.CLOSED_OPTION){
if(val == 0){
txt.setText("Yes");
}
else{
txt.setText("No");
}
}
}
else if(id.equals("Color")){
Object[] options = {"Red", "Green"};
int sel = JOptionPane.showOptionDialog(null,
"Choose a Color!", "Warning",
JOptionPane.DEFAULT_OPTION,
JOptionPane.WARNING_MESSAGE, null,
options, options[0]);
if(sel != JOptionPane.CLOSED_OPTION){
txt.setText("Color Selected: " + options[sel]);
}
}
else if(id.equals("Input")){
String val = JOptionPane.showInputDialog("How mant fingers do you see?");
txt.setText(val);
}
else if(id.equals("3 Vals")){
Object[] selections = {"First", "Second", "Third"};
Object val = JOptionPane.showInputDialog(null,
"Choose one", "Input",
JOptionPane.INFORMATION_MESSAGE,
null, selections, selections[0]);
if(val != null){
txt.setText(val.toString());
}
}
}
};
public MessageBoxes(){
frame = new JFrame("Title");
frame.setSize(250, 250);
frame.getContentPane().setLayout(new FlowLayout());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
for(int i = 0; i < b.length; i++){
frame.getContentPane().add(b[i]);
}
frame.getContentPane().add(txt);
frame.setVisible(true);
}
public void launchJFrame(){
for(int i = 0; i < b.length; i++){
b[i].addActionListener(al);
}
}
public static void main(String [] args){
MessageBoxes messageBoxes = new MessageBoxes();
messageBoxes.launchJFrame();
}
}
Explanation / Answer
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class MessageBoxes{
private JButton[] b = {
new JButton("Alert"),
new JButton("Yes/No"),
new JButton("Color"),
new JButton("Input"),
new JButton("3 Vals"),
};
//add this code ....
//for multiple action listeners..
//Alert
b[0].addActionListener(
new ActionListerner()
{
public void actionPerformed(ActionEvent e)
{
JOptionPane.showMessageDialog(null,
"There's a bug on you!", "Hey!",
JOptionPane.ERROR_MESSAGE);
}
}
);
//yes/no
b[1].addActionListener(
new ActionListerner()
{
public void actionPerformed(ActionEvent e)
{
int val = JOptionPane.showConfirmDialog(null,
"or no", "Chose yes",
JOptionPane.YES_NO_OPTION);
if(val != JOptionPane.CLOSED_OPTION){
if(val == 0){
txt.setText("Yes");
}
else{
txt.setText("No");
}
}
}
}
);
//Color
b[2].addActionListener(
new ActionListerner()
{
public void actionPerformed(ActionEvent e)
{
Object[] options = {"Red", "Green"};
int sel = JOptionPane.showOptionDialog(null,
"Choose a Color!", "Warning",
JOptionPane.DEFAULT_OPTION,
JOptionPane.WARNING_MESSAGE, null,
options, options[0]);
if(sel != JOptionPane.CLOSED_OPTION){
txt.setText("Color Selected: " + options[sel]);
}
}
}
);
//input
b[3].addActionListener(
new ActionListerner()
{
public void actionPerformed(ActionEvent e)
{
String val = JOptionPane.showInputDialog("How mant fingers do you see?");
txt.setText(val);
}
}
);
//3 vals
b[4].addActionListener(
new ActionListerner()
{
public void actionPerformed(ActionEvent e)
{
Object[] selections = {"First", "Second", "Third"};
Object val = JOptionPane.showInputDialog(null,
"Choose one", "Input",
JOptionPane.INFORMATION_MESSAGE,
null, selections, selections[0]);
if(val != null){
txt.setText(val.toString());
}
}
);
private JTextField txt = new JTextField(15);
private JFrame frame;
private ActionListener al = new ActionListener(){
public void actionPerformed(ActionEvent e){
String id = ((JButton)e.getSource()).getText();
if(id.equals("Alert")){
JOptionPane.showMessageDialog(null,
"There's a bug on you!", "Hey!",
JOptionPane.ERROR_MESSAGE);
}
else if(id.equals("Yes/No")){
int val = JOptionPane.showConfirmDialog(null,
"or no", "Chose yes",
JOptionPane.YES_NO_OPTION);
if(val != JOptionPane.CLOSED_OPTION){
if(val == 0){
txt.setText("Yes");
}
else{
txt.setText("No");
}
}
}
else if(id.equals("Color")){
Object[] options = {"Red", "Green"};
int sel = JOptionPane.showOptionDialog(null,
"Choose a Color!", "Warning",
JOptionPane.DEFAULT_OPTION,
JOptionPane.WARNING_MESSAGE, null,
options, options[0]);
if(sel != JOptionPane.CLOSED_OPTION){
txt.setText("Color Selected: " + options[sel]);
}
}
else if(id.equals("Input")){
String val = JOptionPane.showInputDialog("How mant fingers do you see?");
txt.setText(val);
}
else if(id.equals("3 Vals")){
Object[] selections = {"First", "Second", "Third"};
Object val = JOptionPane.showInputDialog(null,
"Choose one", "Input",
JOptionPane.INFORMATION_MESSAGE,
null, selections, selections[0]);
if(val != null){
txt.setText(val.toString());
}
}
}
};
public MessageBoxes(){
frame = new JFrame("Title");
frame.setSize(250, 250);
frame.getContentPane().setLayout(new FlowLayout());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
for(int i = 0; i < b.length; i++){
frame.getContentPane().add(b[i]);
}
frame.getContentPane().add(txt);
frame.setVisible(true);
}
public void launchJFrame(){
for(int i = 0; i < b.length; i++){
b[i].addActionListener(al);
}
}
public static void main(String [] args){
MessageBoxes messageBoxes = new MessageBoxes();
messageBoxes.launchJFrame();
}
}
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