Reverse Polish Notation calculator

[matrix584]

I gotta make another class to use this, and i have no idea how...any
ideas

(please dont post the answer, i just need a little guidance)

import java.io.*;
import java.net.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.text.html.*;
import javax.swing.border.*;


class HPCalculatorApp
extends JFrame
implements ActionListener
{

private JMenuBar menu;
private JMenuItem fileExit;

private static final int
ZERO = 0,
ONE = 1,
TWO = 2,
THREE = 3,
FOUR = 4,
FIVE = 5,
SIX = 6,
SEVEN = 7,
EIGHT = 8,
NINE = 9,
SIGN = 10,
DOT = 11,
ADD = 12,
SUBTRACT = 13,
MULTIPLY = 14,
DIVIDE = 15,
CLEAR = 16,
BACK = 17,
STORE = 18,
RESTORE = 19,
ENTER = 20,
NUM_BUTTONS = 21;

private static final String[] LABELS = {
"+/-", ".", "+", "-", "*", "/", "C", "<-", "MS", "MR", "ENTER"
};

private JButton[] bButtons;
private JLabel visor;
private Font font;

private HPCalculator hp;
private String number;
private boolean entered;

public HPCalculatorApp()
{
hp = new HPCalculator();
number = new String();
entered = false;

font = new Font("SansSerif", Font.PLAIN, 12);

setTitle( "HP Calculator" );
setSize(180, 240);
BorderLayout mainLayout = new BorderLayout();
getContentPane().setLayout(mainLayout);
mainLayout.setVgap(1);

// Create visor
visor = new JLabel("", SwingConstants.RIGHT);
visor.setFont(font);
visor.setPreferredSize(new Dimension(100, 20));
visor.setBorder(new BevelBorder(BevelBorder.LOWERED));
visor.setBackground(Color.white);
getContentPane().add(visor, BorderLayout.NORTH);

// Create buttons
int WIDTH = 30;
int HEIGHT = 30;
bButtons = new JButton[NUM_BUTTONS];
for (int i=0; i<NUM_BUTTONS-1; i++) {
bButtons = new JButton(Integer.toString(i));
bButtons.setPreferredSize(new Dimension(WIDTH, HEIGHT));
bButtons.setForeground(Color.blue);
bButtons.setFont(font);
bButtons.setMargin(new Insets(1, 1, 1, 1));
bButtons.addActionListener(this);
}

for (int i=SIGN; i<=ENTER; i++) {
bButtons = new JButton(LABELS[i-SIGN]);
bButtons.setPreferredSize(new Dimension(WIDTH, HEIGHT));
bButtons.setForeground(Color.red);
bButtons.setFont(font);
bButtons.setMargin(new Insets(1, 1, 1, 1));
bButtons.addActionListener(this);
}

bButtons[SIGN].setForeground(Color.blue);
bButtons[DOT].setForeground(Color.blue);

bButtons[ENTER].setPreferredSize(new Dimension(100, 18));
bButtons[ENTER].setForeground(Color.white);
bButtons[ENTER].setBackground(new Color(155, 155, 155));
bButtons[ENTER].setMargin(new Insets(1, 1, 1, 1));

int VGAP = 1, HGAP = 1;
JPanel centerPanel = new JPanel();
GridLayout grid = new GridLayout(4, 1);
grid.setHgap(HGAP);
grid.setVgap(VGAP);
centerPanel.setLayout(grid);

JPanel row1 = new JPanel();
JPanel row2 = new JPanel();
JPanel row3 = new JPanel();
JPanel row4 = new JPanel();
JPanel row5 = new JPanel();

FlowLayout defLayout;
defLayout = new FlowLayout();
defLayout.setHgap(HGAP);
defLayout.setVgap(VGAP);

row1.setLayout(defLayout);
row1.add(bButtons[NINE]);
row1.add(bButtons[EIGHT]);
row1.add(bButtons[SEVEN]);
row1.add(bButtons[ADD]);
row1.add(bButtons[BACK]);
centerPanel.add(row1);

defLayout = new FlowLayout();
defLayout.setHgap(HGAP);
defLayout.setVgap(VGAP);
row2.setLayout(defLayout);
row2.add(bButtons[SIX]);
row2.add(bButtons[FIVE]);
row2.add(bButtons[FOUR]);
row2.add(bButtons[SUBTRACT]);
row2.add(bButtons[CLEAR]);
centerPanel.add(row2);

defLayout = new FlowLayout();
defLayout.setHgap(HGAP);
defLayout.setVgap(VGAP);
row3.setLayout(defLayout);
row3.add(bButtons[THREE]);
row3.add(bButtons[TWO]);
row3.add(bButtons[ONE]);
row3.add(bButtons[MULTIPLY]);
row3.add(bButtons[STORE]);
centerPanel.add(row3);

defLayout = new FlowLayout();
defLayout.setHgap(HGAP);
defLayout.setVgap(VGAP);
row4.setLayout(defLayout);
row4.add(bButtons[ZERO]);
row4.add(bButtons[SIGN]);
row4.add(bButtons[DOT]);
row4.add(bButtons[DIVIDE]);
row4.add(bButtons[RESTORE]);
centerPanel.add(row4);

defLayout = new FlowLayout();
defLayout.setHgap(HGAP);
defLayout.setVgap(VGAP);
row5.setLayout(defLayout);
row5.add(bButtons[ENTER]);

centerPanel.add(row5);

getContentPane().add(centerPanel, BorderLayout.CENTER);
getContentPane().add(row5, BorderLayout.SOUTH);

// Create menu
menu = new JMenuBar();
setJMenuBar(menu);

fileExit = new JMenuItem("Exit");
fileExit.setFont(font);
fileExit.addActionListener(this);
menu.add(fileExit);

pack();

//Anonymous inner class to terminate program.
this.addWindowListener( new WindowAdapter()
{
public void windowClosing(WindowEvent e)
{
System.exit( 0 );
}
} );//end addWindowListener
}

public void actionPerformed(ActionEvent e)
{
if (e.getSource() instanceof JMenuItem) {
JMenuItem i = (JMenuItem)e.getSource();
if (i == fileExit)
System.exit(0);
}

if (e.getSource() instanceof JButton) {
if (processNumber(e.getSource()))
return;
if (processOperation(e.getSource()))
return;
if (processClear(e.getSource()))
return;
if (processMemory(e.getSource()))
return;
if (processEnter(e.getSource()))
return;

}
}

public static void main(String args[])
{
// Create an instance of the test application
HPCalculatorApp mainFrame = new HPCalculatorApp();
mainFrame.setVisible(true);
}

private void backspace()
{
if (number.length() == 0)
return;
if (entered) {
clearNumber();
return;
}
number = number.substring(0, number.length()-1);
if (number.length() == 1 && number.startsWith("-"))
clearNumber();
else if (number.length() == 2 && number.startsWith("-0"))
clearNumber();
else if (number.length() == 1 && number.startsWith("0"))
clearNumber();
}

private void clearVisor()
{
clearNumber();
updateVisor();
}

private void clearNumber()
{
number = "";
}

private void updateVisor()
{
visor.setText(number);
}

private double getNumber(String n)
{
double num;
try {
num = (double)Double.parseDouble(n);
}
catch (NumberFormatException e) {
return 0.0;
}
return num;
}

private boolean checkNumber(String n)
{
try {
Double.parseDouble(n);
}
catch (NumberFormatException e) {
return false;
}
return true;
}

private boolean addToNumber(int i)
{
if (entered == true || number.length() == 0) {
entered = false;
if (i != 0)
number = Integer.toString(i);
else
number = "0.";
return true;
}

String n = new String(number);
n += i;
if (!checkNumber(n))
return false;
number = n;
entered = false;
return true;
}

private void toNumber(double n)
{
number = Double.toString(n);
}

private boolean invertSign()
{
if (number.length() == 0)
return false;

if (number.startsWith("-"))
number = number.substring(1);
else
number = "-" + number;
entered = false;
return true;
}

private boolean addDot()
{
if (number.length() == 0) {
entered = false;
number = "0.";
return true;
}

if (number.indexOf('.') != -1)
return false;

number += '.';
//?? entered = false;
return true;
}

private boolean processNumber(Object o)
{
for (int i=ZERO; i<=NINE; i++) {
if (bButtons == (JButton)o) {
if (addToNumber(i)) {
updateVisor();
return true;
}
}
}
if (bButtons[SIGN] == (JButton)o) {
if (invertSign()) {
updateVisor();
return true;
}
}
if (bButtons[DOT] == (JButton)o) {
if (addDot()) {
updateVisor();
return true;
}
}

return false;
}

private void add()
{
if (!entered)
enter();
try {
hp.add();
}
catch (Error e) {
return;
}
toNumber(hp.result());
updateVisor();
entered = true;
}

private void subtract()
{
if (!entered)
enter();
try {
hp.subtract();
}
catch (Error e) {
return;
}
toNumber(hp.result());
updateVisor();
entered = true;
}

private void divide()
{
if (!entered)
enter();
try {
hp.divide();
}
catch (Error e) {
return;
}
toNumber(hp.result());
updateVisor();
entered = true;
}

private void multiply()
{
if (!entered)
enter();
try {
hp.multiply();
}
catch (Error e) {
return;
}
toNumber(hp.result());
updateVisor();
entered = true;
}

private boolean processOperation(Object o)
{
if (bButtons[ADD] == (JButton)o) {
add();
return true;
}
else if (bButtons[SUBTRACT] == (JButton)o) {
subtract();
return true;
}
else if (bButtons[DIVIDE] == (JButton)o) {
divide();
return true;
}
else if (bButtons[MULTIPLY] == (JButton)o) {
multiply();
return true;
}
return false;
}

private boolean processClear(Object o)
{
if (bButtons[CLEAR] == (JButton)o) {
clearVisor();
return true;
}
else if (bButtons[BACK] == (JButton)o) {
backspace();
updateVisor();
return true;
}
return false;
}

private boolean processMemory(Object o)
{
if (!checkNumber(number))
return false;

double n;
if (bButtons[STORE] == (JButton)o) {
n = getNumber(number);
hp.store(n);
return true;
}
else if (bButtons[RESTORE] == (JButton)o) {
n = hp.restore();
toNumber(n);
updateVisor();
entered = false;
return true;
}
return false;
}

private boolean enter()
{
if (!checkNumber(number))
return false;
hp.enter(getNumber(number));
entered = true;
return true;
}

private boolean processEnter(Object o)
{
if (bButtons[ENTER] == (JButton)o) {
return enter();
}
return false;
}
}

 

[Roedy Green]

I gotta make another class to use this, and i have no idea how...any
ideas

I won't even look at your class. Here is the generic answer.

If your class has a main method, see
http://mindprod.com/jgloss/main.html
for the fine print, then you can run it from the command line or
simulate a command line with the args[] parameter.

If the class has public static methods, you can use them. Just give
them suitable parameters.

To use the public instance (non-static) methods, you must find a
constructor, and use new to construct an object of that class. then
you can call the public instance methods on it.

see http://mindprod.com/jgloss/static.html
http://mindprod.com/jgloss/instance.html

 

[Oliver Wong]

I won't even look at your class.

I didn't read the OP's code either. It's much too long, and I quickly
got bored with it. Read http://mindprod.com/jgloss/sscce.html, especially
the part about "short":

<quote>
Try to prune away anything not strictly relevant to the problem. In the
process of doing this, you often solve your own problem. If you don't prune,
You are making the task unnecessarily difficult for those you want to help
you by clouding the issue with irrelevancies, or hiding relevancies. If you
don't prune, you are implicitly saying "my time is valuable and yours is
not.", hardly a winning attitude to solicit help. Purely out of self
interest you should prune as much as practical, because if you ask only a
small favour, that minimally inconveniences, irritates or frustrates
another, your chances of someone granting it are much higher. You will also
get more responses, which increases your odds of getting a helpful, correct
response.
</quote>

Also, the OP should state what the exact problem is. That is, (s)he
should say what (s)he expects the program to do, and contrasts it with what
the program actually does.

- Oliver