GUI

[Rich Wilson]

I am new to Java still trying to figure it out and I am lost on this one. I have an assignment for school and I think I did it right but I know I didn't. I can not get the output to output? It should (in a perfect world) output the variable b from calculate() to JTextField paymentField. Any suggestions?

import java.io.*;
import java.text.*;
import java.util.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.lang.Math;
import java.text.DecimalFormat;
 
 
 
public class mortgageweek2 extends JFrame
implements ItemListener,ActionListener {
  
//row1 
JPanel row1 = new JPanel();
JLabel rate = new JLabel("APR", JLabel.CENTER);
JLabel amount = new JLabel("Amount Financed",JLabel.CENTER);
JLabel years = new JLabel("Years Financed",JLabel.CENTER);
JTextField apr = new JTextField (8);
JTextField amountField = new JTextField (8);
JTextField yearsField = new JTextField (8);

//row3
JPanel row3 = new JPanel();
JLabel payment = new JLabel("Monthly payment",JLabel.CENTER);
JTextField paymentField = new JTextField (8);

//row5
JPanel row5 = new JPanel();
JButton close = new JButton("Exit");
JButton start = new JButton("Run");
JButton clear = new JButton("Reset");


 public mortgageweek2() {
 
 
        super("Week 2 mortgage app");
        setSize(650, 350);
         setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         GridLayout layout = new GridLayout(5, 1, 10, 10);
         Container pane = getContentPane();
         pane.setLayout(layout);

  //row1
  FlowLayout layout1 = new FlowLayout(FlowLayout.CENTER,10, 10);
        row1.setLayout(layout1);
  row1.add(rate);
  row1.add(apr);
  row1.add(amount);
  row1.add(amountField);
  row1.add(years);
  row1.add(yearsField);  
        pane.add(row1);
  
  //row3
  FlowLayout layout3 = new FlowLayout(FlowLayout.CENTER,10, 10);
  row3.setLayout(layout3);
  row3.add(payment);
  row3.add(paymentField).setEnabled(false);
  pane.add(row3);
  
  //row5
  FlowLayout layout5 = new FlowLayout(FlowLayout.CENTER,10, 10);
  row5.setLayout(layout5);
  row5.add (start);
  row5.add (clear);
  row5.add (close);
  pane.add (row5);
  
  setVisible(true);
    }
 
public void actionPerformed(ActionEvent event) {
        String command = event.getActionCommand();
  
if (command == "Reset")
            clearAllFields();

if (command=="Run")
calculate();

if (command == "Exit")
close();
  }
  
void clearAllFields(){
paymentField.setText(null);
apr.setText(null);
yearsField.setText(null);

}

void close(){ System.exit(-0);}

void calculate() {

int aprnum = Integer.parseInt("0" + apr.getText());
int yearnum = Integer.parseInt("0" + yearsField.getText());
int amtnum = Integer.parseInt("0" + amountField.getText());

double a = aprnum;
double m = yearnum*12;
double b=((a/1200)+((a/1200)/(Math.pow((1+(a/1200)),(m))-1)))*amtnum;

paymentField.setText(""+b);

}

 
 
public void itemStateChanged(ItemEvent event) {
        Object item = event.getItem();
  
  }
 
    public static void main(String[] arguments) {
        mortgageweek2 frame = new mortgageweek2();
    }
}
 

[ June 30, 2005: Message edited by: Rich Wilson ]

[Dave Wingate]

It looks like you didn't add action listeners to your buttons.

Try replacing:

  
                JPanel row5 = new JPanel();
JButton close = new JButton("Exit");
JButton start = new JButton("Run");
JButton clear = new JButton("Reset");

with:

  
                JPanel row5 = new JPanel();
JButton close = new JButton("Exit");
                close.addActionListener(this);
JButton start = new JButton("Run");
                start.addActionListener(this);
JButton clear = new JButton("Reset");
                clear.addActionListener(this);

[Rich Wilson]

Dave,

I tried it and am now getting an error message that I was getting before when I used (this) is there anything else I need to add back into it?

Thank you for the help

C:\Documents and Settings\Darrin\Desktop\POS 407\WK-2\mortgageweek2.java:33: <identifier> expected
close.addActionListener(this);
^
C:\Documents and Settings\Darrin\Desktop\POS 407\WK-2\mortgageweek2.java:35: <identifier> expected
start.addActionListener(this);
^
C:\Documents and Settings\Darrin\Desktop\POS 407\WK-2\mortgageweek2.java:37: <identifier> expected
clear.addActionListener(this);

[Dave Wingate]

Yeah, I didn't read your code very carefully; sorry. The calls to addActionListener need to happen inside your constructor. Something like this:

import java.io.*;
import java.text.*;
import java.util.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.lang.Math;
import java.text.DecimalFormat;
 
 
 
public class Test extends JFrame
implements ItemListener,ActionListener {
  
//row1 
JPanel row1 = new JPanel();
JLabel rate = new JLabel("APR", JLabel.CENTER);
JLabel amount = new JLabel("Amount Financed",JLabel.CENTER);
JLabel years = new JLabel("Years Financed",JLabel.CENTER);
JTextField apr = new JTextField (8);
JTextField amountField = new JTextField (8);
JTextField yearsField = new JTextField (8);

//row3
JPanel row3 = new JPanel();
JLabel payment = new JLabel("Monthly payment",JLabel.CENTER);
JTextField paymentField = new JTextField (8);

//row5
JPanel row5 = new JPanel();
JButton close = new JButton("Exit");
JButton start = new JButton("Run");
JButton clear = new JButton("Reset");


 public Test() {
super("Week 2 mortgage app");
 
//NEW CODE HERE!!!
close.addActionListener(this);
start.addActionListener(this);
clear.addActionListener(this);
 
 
        
        setSize(650, 350);
         setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         GridLayout layout = new GridLayout(5, 1, 10, 10);
         Container pane = getContentPane();
         pane.setLayout(layout);

  //row1
  FlowLayout layout1 = new FlowLayout(FlowLayout.CENTER,10, 10);
        row1.setLayout(layout1);
  row1.add(rate);
  row1.add(apr);
  row1.add(amount);
  row1.add(amountField);
  row1.add(years);
  row1.add(yearsField);  
        pane.add(row1);
  
  //row3
  FlowLayout layout3 = new FlowLayout(FlowLayout.CENTER,10, 10);
  row3.setLayout(layout3);
  row3.add(payment);
  row3.add(paymentField).setEnabled(false);
  pane.add(row3);
  
  //row5
  FlowLayout layout5 = new FlowLayout(FlowLayout.CENTER,10, 10);
  row5.setLayout(layout5);
  row5.add (start);
  row5.add (clear);
  row5.add (close);
  pane.add (row5);
  
  setVisible(true);
    }
 
public void actionPerformed(ActionEvent event) {
        String command = event.getActionCommand();
  
if (command == "Reset")
            clearAllFields();

if (command=="Run")
calculate();

if (command == "Exit")
close();
  }
  
void clearAllFields(){
paymentField.setText(null);
apr.setText(null);
yearsField.setText(null);

}

void close(){ System.exit(-0);}

void calculate() {

int aprnum = Integer.parseInt("0" + apr.getText());
int yearnum = Integer.parseInt("0" + yearsField.getText());
int amtnum = Integer.parseInt("0" + amountField.getText());

double a = aprnum;
double m = yearnum*12;
double b=((a/1200)+((a/1200)/(Math.pow((1+(a/1200)),(m))-1)))*amtnum;

paymentField.setText(""+b);

}

 
 
public void itemStateChanged(ItemEvent event) {
        Object item = event.getItem();
  
  }
 
    public static void main(String[] arguments) {
        Test frame = new Test();
    }
}
  

[Rich Wilson]

Thank you I was hoping it was something stupid and it was. I guess it is just something that only time and experience will fix.