Hey guys! This is really a great forum and you people are a lot nicer than the Sun guys
Anyway...I need some help with this program again. Thought I would post a new question for a new problem. Thanks to hardwired.. I've come a long way with it, but the graph is not showing after calculations are made and amortization is done...when the user clicks on Show Graph, the new window pops up but it is blank. Could someone take a look and let me know what you think? Thanks!
import java.awt.*;
import java.awt.event.*;
import java.awt.font.*;
import java.awt.geom.*;
import java.io.*;
import java.text.*;
import javax.swing.*;
import javax.swing.border.*;
import javax.swing.JComboBox;
public class MC extends JFrame implements ActionListener {
JTextField principalTxt, termTxt, rateTxt, monthlyPaymentTxt;
JTextArea displayArea;
JButton calculateButton, graphButton, amortizeButton, clearButton, exitButton;
JComboBox options;
//formatting variables
DecimalFormat df = new DecimalFormat("\u00A4#,##0.00"); //currency
DecimalFormat pf = new DecimalFormat("#,##0.00%"); //percentages
DecimalFormat mi = new DecimalFormat("#,##0.000%"); //percentages
// Can these 6 be removed and declared as local variables?
int term = 0;
double principal = 0;
double rate = 0;
double monthlyPayment = 0;
double interest = 0;
int notePeriod = 0;
int[] termArray;
double[] rateArray;
private float[] principalAmts;
private float[] interestAmts;
public MC() {
super ("Mortgage Payment Calculator by S Kemen");
setSize(550, 500);
setDefaultCloseOperation(EXIT_ON_CLOSE);
load();
setVisible(true);
// Initialize components.
JPanel row1 = new JPanel();
JLabel mortgageLabel = new JLabel("MORTGAGE PAYMENT CALCULATOR", JLabel.CENTER);
JPanel row2 = new JPanel(new GridLayout(1, 2));
JLabel principalLabel = new JLabel("Mortgage Principal $",JLabel.LEFT);
principalTxt = new JTextField(10);
JPanel row3 = new JPanel(new GridLayout(1, 2));
JLabel termLabel = new JLabel("Mortgage Term (Yrs)",JLabel.LEFT);
termTxt = new JTextField(10);
JPanel row4 = new JPanel(new GridLayout(1, 2));
JLabel rateLabel = new JLabel("Interest Rate (%)", JLabel.LEFT);
rateTxt = new JTextField(10);
JPanel row5 = new JPanel(new GridLayout(1, 2));
JLabel presetLabel = new JLabel("Preset Term and Interest Rate:", JLabel.LEFT);
JPanel row6 = new JPanel(new GridLayout(1,2));
options = new JComboBox();
MessageFormat mf = new MessageFormat("{0} years at {1,number,#.##}%");
JLabel choiceLabel = new JLabel(" (choose rate)");
for (int i = 0; i < termArray.length; i++) {
options.addItem(mf.format(new Object[] { new Integer(termArray [i]),
new Double(rateArray[i])}));
}
JPanel row7 = new JPanel(new GridLayout(1, 2));
JLabel monthlyPaymentLabel = new JLabel("Monthly Payment $", JLabel.LEFT);
monthlyPaymentTxt = new JTextField(10);
//create buttons
JPanel button = new JPanel(new FlowLayout(FlowLayout.CENTER, 10, 10));
graphButton = new JButton("Display Graph");
amortizeButton = new JButton("Amortize Payments");
clearButton = new JButton("Clear");
exitButton = new JButton("Exit");
calculateButton = new JButton("Calculate");
//create textarea to display Amortize output
displayArea = new JTextArea(10, 45);
JScrollPane scroll = new JScrollPane(displayArea);
Container pane = getContentPane();
// Set layout before adding components.
pane.setLayout(new BoxLayout( pane, BoxLayout.Y_AXIS));
Border rowborder = new EmptyBorder( 3, 10, 3, 10 );
pane.add(row1);
row1.add(mortgageLabel);
row1.setMaximumSize( new Dimension( 10000, row1.getMinimumSize().height));
row1.setBorder( rowborder);
pane.add(row2);
row2.add(principalLabel);
row2.add(principalTxt);
row2.setMaximumSize( new Dimension( 10000, row2.getMinimumSize().height));
row2.setBorder( rowborder);
pane.add(row3);
row3.add(termLabel);
row3.add(termTxt);
row3.setMaximumSize( new Dimension( 10000, row3.getMinimumSize().height));
row3.setBorder( rowborder);
pane.add(row4);
row4.add(rateLabel);
row4.add(rateTxt);
row4.setMaximumSize( new Dimension( 10000, row4.getMinimumSize().height));
row4.setBorder( rowborder);
pane.add(row5);
row5.add(presetLabel);
row5.setMaximumSize( new Dimension( 10000, row4.getMinimumSize().height));
row5.setBorder( rowborder);
pane.add(row6);
row6.add(choiceLabel);
row6.setMaximumSize( new Dimension( 10000, row4.getMinimumSize().height));
row6.setBorder( rowborder);
JPanel radioPanel = new JPanel();
radioPanel.setLayout(new FlowLayout(FlowLayout.LEFT, 4, 4 ));
radioPanel.add(options);
pane.add(radioPanel);
radioPanel.setMaximumSize( new Dimension( 10000,
radioPanel.getMinimumSize().height));
radioPanel.setBorder( rowborder);
pane.add(row7);
row7.add(monthlyPaymentLabel);
row7.add(monthlyPaymentTxt);
monthlyPaymentTxt.setEnabled(false); //set payment amount uneditable
monthlyPaymentTxt.setFocusable(false);
row7.setMaximumSize( new Dimension( 10000, row5.getMinimumSize().height));
row7.setBorder( rowborder);
//Add buttons
button.add(calculateButton);
button.add(clearButton);
button.add(exitButton);
button.add(amortizeButton);
button.add(graphButton);
pane.add(button);
button.setMaximumSize( new Dimension( 10000, button.getMinimumSize().height));
//scroll text pane for Amortize output
scroll.setBorder(BorderFactory.createEmptyBorder(10,10,10,10));
pane.add(scroll);
setContentPane(pane);
//add listeners for buttons and combo box
options.addActionListener(this);
clearButton.addActionListener(this);
exitButton.addActionListener(this);
calculateButton.addActionListener(this);
amortizeButton.addActionListener(this);
graphButton.addActionListener(this);
}
public void actionPerformed(ActionEvent event) {
Object command = event.getSource();
if(command == calculateButton) { //function for Calculate button
try {
principal = Double.parseDouble(principalTxt.getText());
} catch(NumberFormatException e) {
//catch null pointer exception if Principal is null
JOptionPane.showMessageDialog(null, "Invaild Entry! Please Try Again",
"ERROR", JOptionPane.ERROR_MESSAGE);
}
try {
//Get input from Term text box, checked first before combo box
term = Integer.parseInt(termTxt.getText());
rate = Double.parseDouble(rateTxt.getText()); //Input from Rate text box
} catch(NumberFormatException e) {
//If Term and Rate are null, buttons are checked for input values
//Set rate and term based on which item in the combobox is selected
//If no option is selected and combo box null,
// this is an actual error.
JOptionPane.showMessageDialog(null, "Invaild Entry! " +
"Please Try Again",
"ERROR", JOptionPane.ERROR_MESSAGE);
}
interest = rate / 100 / 12; //Monthly interst rate
notePeriod = term * 12; //Number of months over which loan is amortized
//calculation formula
monthlyPayment = (principal * interest) /
(1 - Math.pow(1 + interest, -notePeriod));
monthlyPaymentTxt.setText("" + df.format(monthlyPayment));
}
if(command == clearButton) { //Function for Clear button
principalTxt.setText("");
monthlyPaymentTxt.setText("");
rateTxt.setText("");
termTxt.setText("");
displayArea.setText("");
}
if(command == exitButton) { //Function for Exit button
System.exit(0);
}
if (command == amortizeButton) { //Function for Amortize button
//Amoritization variables
double loanBalance = notePeriod * monthlyPayment;
// You need to use the member variables with these two names
// so you can send them to your GraphPanel. Instantiate them
// here and fill the elements in this loop. The member
// variables remain null and choke up GraphPanel.
double interestPaid = 0; //Interest paid on the loan
double monthlyPrincipal = 0; //Principal in each monthly payment
//running total of principal after payment
double principalBalance = principal;
//String for output
String titles = "Month\t Principal\t\tInterest\t\tBalance\n";
displayArea.setText(titles);
displayArea.append(""); //Inserts a blank line
interestAmts = new float[term*12];
principalAmts = new float[term*12];
//This loop is used to calculate and display the payment schedule information
for(int counter = 0; counter < term * 12 - 0; counter++) { //start outer loop
//start inner loop
interestPaid = principalBalance * interest;
interestAmts[counter] = (float)interestPaid;
monthlyPrincipal = monthlyPayment - interestPaid;
principalAmts[counter] = (float)monthlyPrincipal;
loanBalance = loanBalance - monthlyPayment;
principalBalance = principalBalance - monthlyPrincipal;
//formatting for output
displayArea.setCaretPosition(0);
displayArea.append((counter +1) + ")\t" +
df.format(monthlyPrincipal)+"\t\t" +
df.format(interestPaid)+"\t\t" +
df.format(principalBalance)+"\n");
}
}
if (command == graphButton) { //Function for Graph button
JDialog d = new JDialog(this, false);
d.getContentPane().add(new GraphPanel(principalAmts, interestAmts));
d.setSize(800,600);
d.setLocation(200,100);
d.setVisible(true);
}
}
//reading from sequential file
private void load() {
Reader fis;
try {
fis = new InputStreamReader(getClass().getResourceAsStream("data.txt"));
BufferedReader br = new BufferedReader( fis );
termArray = new int[4];
rateArray = new double[4];
String line;
int i = 0;
while((line = br.readLine()) != null) {
String[] s = line.split(",");
termArray[ i ] = Integer.parseInt(s[0].trim());
rateArray[ i ] = Double.parseDouble(s[1].trim());
i++;
}
br.close();
} catch ( Exception e1 ) {
e1.printStackTrace( );
}
}
class GraphPanel extends JPanel
{
final int
HPAD = 60,
VPAD = 40;
int[] data;
Font font;
float[] principalAmts;
float[] interestAmts;
public GraphPanel(float[] principalAmts, float[] interestAmts)
{
font = new Font("lucida sans regular", Font.PLAIN, 16);
setBackground(Color.white);
}
protected void paintComponent(Graphics g)
{
super.paintComponent(g);
Graphics2D g2 = (Graphics2D)g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g2.setFont(font);
FontRenderContext frc = g2.getFontRenderContext();
int w = getWidth();
int h = getHeight();
// scales
float xInc = (w - HPAD - VPAD) / (interestAmts.length - 1);//11f; //distance between each point
float yInc = (h - 2*VPAD) / 10f;
int[] dataVals = getDataVals(); //min and max values for y-axis
float yScale = dataVals[2] / 10f;
// ordinate (y - axis)
g2.draw(new Line2D.Double(HPAD, VPAD, HPAD, h - VPAD));
// plot tic marks
float x1 = HPAD, y1 = VPAD, x2 = HPAD - 3, y2;
for(int j = 0; j < 10; j++)
{
g2.draw(new Line2D.Double(x1, y1, x2, y1));
y1 += yInc;
}
// labels
String text; LineMetrics lm;
float xs, ys, textWidth, height;
for(int j = 0; j <= 10; j++)
{
text = String.valueOf(dataVals[1] - (int)(j * yScale));
textWidth = (float)font.getStringBounds(text, frc).getWidth();
lm = font.getLineMetrics(text, frc);
height = lm.getAscent();
xs = HPAD - textWidth - 7;
ys = VPAD + (j * yInc) + height/2;
g2.drawString(text, xs, ys);
if(j == 0) g2.drawString("Principal", xs, ys - 15);
}
// abcissa (x - axis)
g2.draw(new Line2D.Double(HPAD, h - VPAD, w - VPAD, h - VPAD));
// tic marks
x1 = HPAD; y1 = h - VPAD; y2 = y1 + 3;
for(int j = 0; j < interestAmts.length; j++)
{
g2.draw(new Line2D.Double(x1, y1, x1, y2));
x1 += xInc;
}
// labels
ys = h - VPAD;
for(int j = 0; j < interestAmts.length; j++)
{
text = String.valueOf(j + 1);
textWidth = (float)font.getStringBounds(text, frc).getWidth();
lm = font.getLineMetrics(text, frc);
height = lm.getHeight();
xs = HPAD + j * xInc - textWidth/2;
g2.drawString(text, xs, ys + height);
if( j == (interestAmts.length - 1)) g2.drawString("Year", (int)w /2 , ys + height + 15);
}
// plot data
float yy2 = 0, yy1 = 0, xx2 = 0, xx1;
x1 = HPAD;
xx1 = HPAD;
yScale = (float)(h - 2*VPAD) / dataVals[2];
for(int j = 0; j < interestAmts.length; j++)
{
g.setColor(Color.blue);
y1 = VPAD + (h - 2*VPAD) - (principalAmts[j] - dataVals[0]) * yScale;
g2.fillOval((int)x1, (int)y1 - 2, 5, 5);
if(j > 0)
g2.draw(new Line2D.Double(x1, y1, x2, y2));
x2 = x1;
y2 = y1;
x1 += xInc;
g.setColor(Color.red);
yy1 = VPAD + (h - 2*VPAD) - (interestAmts[j] - dataVals[0]) * yScale;
g2.fillOval((int)xx1, (int)yy1 - 1, 5, 5);
if(j > 0)
g2.draw(new Line2D.Double(xx1, yy1, xx2, yy2));
xx2 = xx1;
yy2 = yy1;
xx1 += xInc;
}
}
private int[] getDataVals()
{
int max = Integer.MIN_VALUE;
int min = Integer.MAX_VALUE;
int j = interestAmts.length -1;
max = (int)principalAmts[j];
min = (int)interestAmts[j];
int span = max - min;
return new int[] { min, max, span };
}
}
public static void main(String[] args) {
MC smc = new MC();
}
}