import java.awt.*;
import java.awt.event.*;
import javax.swing.* ;
import javax.swing.JOptionPane ;
import java.io.*;

public class MyCalc extends JFrame
implements ActionListener {

private JButton bOne, bTwo, bThree, bFour, bFive,
bSix, bSeven, bEight, bNine, bZero, bExit,
bMult, bDiv, bSub, bPlus, bCEnt, bCAll, bEquals,
bPlusMinus, bExp, bMPlus, bMMinus, bHelp,
bFact, bAbout, bOneDivX, bSqrt, bDecPt ;
private JTextField enterBox ;
private JPanel textPanel, exitPanel, buttonPanel, functionPanel ;
private Container c ;
private Font font;
private String firstNum = new String(""), secondNum = new String(""), tempStr ;
private boolean myDiag = false, result = true ,
firstNumSet = false, secondNumSet = false,
pendingOp = false ;
private double aNum, dNum1 = 0.0, dNum2 = 0.0 , answer = 0.0,
tempD = 0.0 , minusOne = -1.0 ;
private double dArray[] = new double[ 10 ] ;
private int opCode = -1, tempInt = 0, tempInt2 = 0,
dArrayPtr = 0, pendingOpCode = -1 ;

/** MyCalc() - constructor used for initialization */
MyCalc() {

super( "Calculator" );
setup() ;

setSize( 350, 300 ); /** sets the size of the frame */
setLocation( 200, 200 ) ; /** sets the location of the frame on the screen*/
show(); /** makes the frame visible */
}

/**
* The setup() method is used to allocate the panel and
* button objects using the new function.
*/
private void setup() {
c = getContentPane() ;

/** setup text field and panel */
enterBox = new JTextField( 15 ) ;
enterBox.setText( "..........." );
enterBox.setEditable( false );
enterBox.setBackground( Color.white );
enterBox.setHorizontalAlignment( JTextField.RIGHT );
enterBox.addKeyListener(
/** this code reprimes the enterbox and avoids exceptions */
new KeyAdapter() {
public void keyPressed ( KeyEvent e ) {
if ( result ) {
MyPrint( "The value of result is " + result +
"this is from the enterbox keylistener." );
result = false ;
enterBox.setText( "" );
}
}
}
);
textPanel = new JPanel() ;
textPanel.add(enterBox ) ;

c.add( textPanel , BorderLayout.NORTH ) ;

/** setup button Panel and the number buttons */
buttonPanel = new JPanel() ;
c.add( buttonPanel , BorderLayout.CENTER ) ;

bZero = new JButton( "0" ) ;
bZero.setFont( new Font("Sanserif", Font.BOLD, 16 ) );
bOne = new JButton( "1" ) ;
bTwo = new JButton( "2" ) ;
bThree = new JButton( "3" ) ;
bFour = new JButton( "4" ) ;
bFive = new JButton( "5" ) ;
bSix = new JButton( "6" ) ;
bSeven = new JButton( "7" ) ;
bEight = new JButton( "8" ) ;
bNine = new JButton( "9" ) ;
bExit = new JButton( "Exit" ) ;
bMult = new JButton( "*" ) ;
bMult.setFont( new Font("Sanserif", Font.BOLD, 20 ) );
bDiv = new JButton( "/" ) ;
bDiv.setFont( new Font("Sanserif", Font.BOLD, 20 ) );
bSub = new JButton( "-" ) ;
bSub.setFont( new Font("Sanserif", Font.BOLD, 24 ) );
bPlus = new JButton( "+" ) ;
bPlusMinus = new JButton( "+/-" ) ;
bPlusMinus.setFont( new Font("Sanserif", Font.BOLD, 16 ) );
bEquals = new JButton( "=" ) ;
bEquals.setFont( new Font("Sanserif", Font.BOLD, 16 ) );
bPlus = new JButton( "+" ) ;
bPlus.setFont( new Font("Sanserif", Font.BOLD, 16 ) );
bExp = new JButton( "Pow" ) ;
bExp.setFont( new Font("Sanserif", Font.BOLD, 12 ) );
bOneDivX = new JButton( "1/x" ) ;
bOneDivX.setFont( new Font("Sanserif", Font.BOLD, 16 ) );
bSqrt = new JButton( "SQRT" ) ;
bSqrt.setFont( new Font("Sanserif", Font.BOLD, 12 ) );
bDecPt = new JButton( "." ) ;
bDecPt.setFont( new Font("Sanserif", Font.BOLD, 22 ) );

/** assign an event handler to the button and
* indicate that the responses will be handled
* inside this class, MyCalc. */
bZero.addActionListener( this );
bOne.addActionListener( this );
bTwo.addActionListener( this );
bThree.addActionListener( this );
bFour.addActionListener( this );
bFive.addActionListener( this );
bSix.addActionListener( this );
bSeven.addActionListener( this );
bEight.addActionListener( this );
bNine.addActionListener( this );
bExit.addActionListener( this );
bMult.addActionListener( this );
bDiv.addActionListener( this );
bSub.addActionListener( this );
bPlus.addActionListener( this );
bPlusMinus.addActionListener( this );
bEquals.addActionListener( this );
bExp.addActionListener( this );
bOneDivX.addActionListener( this );
bSqrt.addActionListener( this );
bDecPt.addActionListener( this );

/** add the following buttons to the buttonPanel panel. */
buttonPanel.add( bSeven ) ;
buttonPanel.add( bEight ) ;
buttonPanel.add( bNine ) ;
buttonPanel.add( bMult ) ;

buttonPanel.add( bFour ) ;
buttonPanel.add( bFive ) ;
buttonPanel.add( bSix ) ;
buttonPanel.add( bDiv ) ;

buttonPanel.add( bOne ) ;
buttonPanel.add( bTwo ) ;
buttonPanel.add( bThree ) ;
buttonPanel.add( bSub ) ;

buttonPanel.add( bPlusMinus ) ;
buttonPanel.add( bZero ) ;
buttonPanel.add( bDecPt ) ;
buttonPanel.add( bPlus ) ;

buttonPanel.add( bExp );
buttonPanel.add( bOneDivX );
buttonPanel.add( bSqrt );
buttonPanel.add( bEquals ) ;

buttonPanel.setLayout( new GridLayout( 6, 5, 5, 5 ) );

/** setup function panel and its buttons*/
functionPanel = new JPanel() ;
c.add( functionPanel , BorderLayout.EAST ) ;
functionPanel.setLayout( new GridLayout( 6, 1, 5, 3 ) );

bCEnt = new JButton( "CE" ) ;
bCEnt.setFont( new Font("Sanserif", Font.BOLD, 14 ) );
bCAll = new JButton( "CA" ) ;
bCAll.setFont( new Font("Sanserif", Font.BOLD, 14 ) );
bMPlus = new JButton( "M+" ) ;
bMPlus.setFont( new Font("Sanserif", Font.BOLD, 14 ) );
bMMinus = new JButton( "M-" ) ;
bMMinus.setFont( new Font("Sanserif", Font.BOLD, 14 ) );
bFact = new JButton( "! n" ) ;
bFact.setFont( new Font("Sanserif", Font.BOLD, 20 ) );

/** add the following buttons to the functionPanel panel. */
functionPanel.add( bCEnt ) ;
functionPanel.add( bCAll );
functionPanel.add( bMPlus );
functionPanel.add( bMMinus );
functionPanel.add( bFact );

bCEnt.addActionListener( this );
bCEnt.setBackground( Color.blue ) ;
bCEnt.setForeground( Color.white );
bCAll.addActionListener( this );
bCAll.setBackground( Color.blue ) ;
bCAll.setForeground( Color.white );
bMPlus.addActionListener( this );
bMPlus.setBackground( Color.blue ) ;
bMPlus.setForeground( Color.white );
bMMinus.addActionListener( this );
bMMinus.setBackground( Color.blue ) ;
bMMinus.setForeground( Color.white );
bFact.addActionListener( this );
bFact.setBackground( Color.blue ) ;
bFact.setForeground( Color.white );

/** setup exit panel and its buttons */
exitPanel = new JPanel() ;
c.add( exitPanel , BorderLayout.SOUTH ) ;
bExit = new JButton( "Exit" ) ;
bExit.setFont( new Font("Sanserif", Font.BOLD, 16 ) );
bExit.setBackground( Color.red ) ;
bExit.setForeground( Color.white );
bHelp = new JButton( "Help" ) ;
bHelp.setFont( new Font("Sanserif", Font.BOLD, 16 ) );
bHelp.setBackground( Color.blue ) ;
bHelp.setForeground( Color.white );
bAbout = new JButton( "About" ) ;
bAbout.setFont( new Font("Sanserif", Font.BOLD, 14 ) );
bAbout.setBackground( Color.darkGray ) ;
bAbout.setForeground( Color.white );

/** add the following buttons to the exitPanel panel. */
exitPanel.add( bExit ) ;
exitPanel.add( bHelp ) ;
exitPanel.add( bAbout ) ;

bExit.addActionListener( this );
bHelp.addActionListener( this );
bAbout.addActionListener( this );

}

/** This is the method that is called to respond to a button event */
public void actionPerformed( ActionEvent e ) {
if ( result ) {
/** If result =s true, set the text field to vlank */
MyPrint( "The value of result is " + result );
result = false ;
enterBox.setText( "" );
}

if ( !pendingOp && opCode == 99 ) {
/** If opCode =s 99, then the =s button was pressed */
enterBox.setText( "" );
MyPrint( "The value of opCode is " + opCode );
pendingOpCode = -1 ;
firstNumSet = false ;
firstNum = "" ;
}

if ( e.getSource() == bDecPt ) {
MyPrint( "The decimal point button was pressed." );
enterBox.setText( enterBox.getText() + "." ) ;
}
else if ( e.getSource() == bZero ) {
MyPrint( "The zero button was pressed. And pendingOp is " + pendingOp );
enterBox.setText( enterBox.getText() + "0" ) ;
}
else if ( e.getSource() == bOne ) {
MyPrint( "The one button was pressed. And pendingOp is " + pendingOp );
enterBox.setText( enterBox.getText() + "1" ) ;
}
else if ( e.getSource() == bTwo ) {
MyPrint( "The two button was pressed. And pendingOp is " + pendingOp );
enterBox.setText( enterBox.getText() + "2" ) ;
}
else if ( e.getSource() == bThree ) {
MyPrint( "The Three button was pressed. And pendingOp is " + pendingOp);
enterBox.setText( enterBox.getText() + "3" ) ;
}
else if ( e.getSource() == bFour ) {
MyPrint( "The Four button was pressed. And pendingOp is " + pendingOp );
enterBox.setText( enterBox.getText() + "4" ) ;
}
else if ( e.getSource() == bFive ) {
MyPrint( "The Five button was pressed. And pendingOp is " + pendingOp );
enterBox.setText( enterBox.getText() + "5" ) ;
}
else if ( e.getSource() == bSix ) {
MyPrint( "The Six button was pressed. And pendingOp is " + pendingOp );
enterBox.setText( enterBox.getText() + "6" ) ;
}
else if ( e.getSource() == bSeven ) {
MyPrint( "The Seven button was pressed. And pendingOp is " + pendingOp );
enterBox.setText( enterBox.getText() + "7" ) ;
}
else if ( e.getSource() == bEight ) {
MyPrint( "The Eight button was pressed. And pendingOp is " + pendingOp );
enterBox.setText( enterBox.getText() + "8" ) ;
}
else if ( e.getSource() == bNine ) {
MyPrint( "The Nine button was pressed. And pendingOp is " + pendingOp );
enterBox.setText( enterBox.getText() + "9" ) ;
}
else if ( e.getSource() == bExit ) {
MyPrint( "The Exit button was pressed." );
sysExit() ;
}
else if ( e.getSource() == bMult ) {
MyPrint( "The Mult button was pressed. And pendingOp is " + pendingOp );
multOp() ;
}
else if ( e.getSource() == bDiv ) {
MyPrint( "The Div button was pressed. And pendingOp is " + pendingOp );
divOp() ;
}
else if ( e.getSource() == bSub ) {
MyPrint( "The Sub button was pressed. And pendingOp is " + pendingOp );
subOp() ;
}
else if ( e.getSource() == bPlus ) {
MyPrint( "The Plus button was pressed. And pendingOp is " + pendingOp );
plusOp() ;
}
else if ( e.getSource() == bCEnt ) {
MyPrint( "The CEnt button was pressed." );
enterBox.setText( "" ) ;
}
else if ( e.getSource() == bSqrt ) {
MyPrint( "The bSqrt button was pressed. And pendingOp is " + pendingOp );

MySqrt() ;
}
else if ( e.getSource() == bOneDivX ) {
MyPrint( "The bOneDivX button was pressed. And pendingOp is " + pendingOp );
OneDivX() ;
}
else if ( e.getSource() == bCAll ) {
MyPrint( "The CAll button was pressed." );
enterBox.setText( "" ) ;
firstNum = "" ;
firstNumSet = false ;
secondNum = "" ;
answer= 0.0 ;
opCode = -1 ;
}
else if ( e.getSource() == bEquals ) {
MyPrint( "The Equals button was pressed. And pendingOp is " + pendingOp +
" The opCode value is " + opCode );

if ( pendingOp ) {
opCodeMethod() ;
opCode = -1 ;
}

secondNum = enterBox.getText() ;

opCodeMethod() ;

firstNum = "" + answer ;
result = true ;
}
else if ( e.getSource() == bPlusMinus ) {
MyPrint( "The PlusMinus button was pressed." );
opCode = -1 ;

PlusMinus() ;
}
else if ( e.getSource() == bExp ) {
MyPrint( "The Power button was pressed." );
secondNumSet = false ;
powerOp() ;
}
else if ( e.getSource() == bMPlus ) {
MyPrint( "1a: The MPlus button was pressed. pendingOp =s " + pendingOp);
if ( dArrayPtr < 10 ) { /** array hold 10 entries */
if ( !pendingOp ) {
if ( opCode == 99 ) {
//enterBox.setText( "" );
MyPrint( "1b: The value of opCode is " + opCode +
" firstNum =s " + firstNum + " answer =s " + answer );
pendingOpCode = -1 ;
firstNumSet = true ;
firstNum = "" + answer ;
dArray [ dArrayPtr ] =
Double.parseDouble( "" + answer ) ;
dArrayPtr++ ;
enterBox.setText( firstNum ) ;
MyPrint( "1c: The value of dArrayPtr is " + dArrayPtr );
}
else {
/** This code is entered if the =s button was not just pressed */
firstNum = "" + enterBox.getText( );
firstNumSet = true ;
dArray [ dArrayPtr ] =
Double.parseDouble( "" + firstNum ) ;
dArrayPtr++ ;
MyPrint( "1d: The value of dArrayPtr is " + dArrayPtr );
}
}
else if ( !enterBox.getText().equals( "" ) ) {
dArray [ dArrayPtr ] =
Double.parseDouble( enterBox.getText() ) ;
dArrayPtr++ ;
firstNumSet = true ;
firstNum = "" + answer ;
MyPrint( "1d: The value of dArrayPtr is " + dArrayPtr );
}
else {
JOptionPane.showMessageDialog( this, "A number must be entered befor clicking

the M+ button" ,
"Attempted to store a blank number.",
JOptionPane.ERROR_MESSAGE );
}
}
result = true ;
}
else if ( e.getSource() == bMMinus ) {
/** This code retrieves values from the array stack */
MyPrint( "The MMinus button was pressed." ) ;
if ( dArrayPtr > 0 ) {
enterBox.setText( "" + dArray [ dArrayPtr-1 ] ) ;
firstNum = "" + answer ;
answer = dArray [ dArrayPtr-1 ] ;
dArrayPtr-- ;
MyPrint( "1a: The retrieved value is " + answer ) ;
}
else {
enterBox.setText( "" ) ;
MyPrint( "1b: There are no more values to retrieve." ) ;
JOptionPane.showMessageDialog( this, "There are no more values to retrieve using

M-." ,
"No More Values.",
JOptionPane.ERROR_MESSAGE );
}

/**
* Code changed on 9/10/2003 to allow result to be a
* first operand.
*/
if ( pendingOp ) {
secondNumSet = true ;
secondNum = "" + answer ;
}
else {
MyPrint( "1a- MMinus: The value of answer is " + answer );
secondNum = "" ;
opCode = -1 ;
dNum2 = 0.0 ;
dNum1 = answer ;
secondNumSet = false ;
firstNum = "" + answer ;
firstNumSet = true ;
pendingOp = false ;
enterBox.setText( "" + answer ) ;
}
}
else if ( e.getSource() == bHelp ) {
MyPrint( "The Help button was pressed." );
File hd = new File("help_doc.html");
//File net = new File("Netscp.exe");
String helpStr = hd.getAbsolutePath() ;
Runtime rt = Runtime.getRuntime();
/* String[] callAndArgs = { "c:\\Program Files\\Internet Explorer\\IExplore.exe" ,
"" +
E:\MyExamples\SimpleCalc\Calc\help_doc.html }; */
String[] callAndArgs = { "c:\\Program Files\\Internet Explorer\\IExplore.exe" ,
"" + helpStr };

try {

Process child = rt.exec( callAndArgs );
child.waitFor();
MyPrint ("Process exit code is: " +
child.exitValue());
}
catch(IOException e2) {
MyPrint (
"IOException starting process!");
}
catch(InterruptedException e3) {
System.err.println(
"Interrupted waiting for process!");
}
}
else if ( e.getSource() == bFact ) {
MyPrint( "1a- bFact(): opCode is " + opCode + " firstNum is " + firstNum ) ;
if ( opCode == 99 ) {
tempInt = ( int ) answer ;
}
else if ( !enterBox.getText().equals( "" ) ) {
MyPrint( "1b- bFact(): The value of enterBox.getText() is " + enterBox.getText()

);
tempInt = Integer.parseInt( enterBox.getText() ) ;
MyPrint( "1c- bFact(): The value of tempInt is " + tempInt );
}
else if ( firstNumSet ) {
MyPrint( "1d- bFact() The value of firstNum is " + firstNum ) ;
tempInt = (int)Double.parseDouble( firstNum ) ;
MyPrint( "1e- bFact(): The value of tempInt is " + tempInt );
}

MyPrint( "1f- bFact(): The value of tempInt is " + tempInt );
tempInt2 = 1 ;
for( int ii = 1 ; ii < tempInt + 1; ii++ ) {
tempInt2 *= ii ;
}
enterBox.setText( "" + tempInt2 ) ;
/**
* Code changed on 9/10/2003 to allow result to be a
* first operand.
*/
answer = (double)tempInt2 ;
MyPrint( "1g- factorial: The value of answer is " + answer );
secondNum = "" ;
opCode = -1 ;
dNum2 = 0.0 ;
dNum1 = answer ;
secondNumSet = false ;
firstNum = "" + answer ;
firstNumSet = true ;
pendingOp = false ;
}
else if ( e.getSource() == bAbout ) {
MyPrint( "The About button was pressed." );
Runtime rt = Runtime.getRuntime();
String[] callAndArgs = { "c:\\Program Files\\Internet Explorer\\IExplore.exe" ,
"http://pakfar.blogfa.com " };
try {
Process child = rt.exec(callAndArgs);
child.waitFor();
MyPrint ("Process exit code is: " +
child.exitValue());
}
catch(IOException e2) {
MyPrint( "IOException starting process!");
}
catch(InterruptedException e3) {
MyPrint( "Interrupted waiting for process!");
}
}

} /** ***** End of actionPerformed() ****************/

/** checkFirstNum - checks for a number and ensures that it is not null */
private boolean checkFirstNum( ) {
boolean retCode = false ;

if ( !firstNumSet ) {
if ( !enterBox.getText().equals( "" ) ) {
firstNum = enterBox.getText() ;
firstNumSet = true ;
result = true ;
retCode = true ;
MyPrint( "1a- In checkFirstNum( ) -- firstNum =s " + firstNum);
}
}
else if ( !firstNum.equals( "" ) ) {
result = true ;
retCode = true ;
MyPrint( "1b- In checkFirstNum( ) firstNumSet is " + firstNumSet );
}

return retCode ;
} /** ***** End of checkFirstNum() ****************/

/** setResults() - enters the result of an operation in the textbox and the firstNum */
private void setResults() {

enterBox.setText( "" + answer );
firstNum = "" + answer ;
firstNumSet = true ;
result = true ;
pendingOp = false ;
} /** ***** End of checkFirstNum() ****************/

/** opCodeMethod() - determines if there is a pending op to perform
* - if so, that operation is performed
* - if not, the current operation is performed
* */
private void opCodeMethod() {
int currentOpCode = -1 ;

MyPrint( "In opCodeMethod() with an opCode of " + opCode );

/** Check if there is a pending operation that must
* be performed before the current operation is
* performed. */
if ( pendingOp ) {
currentOpCode = pendingOpCode ;
pendingOp = false ;
}
else {
currentOpCode = opCode ;
}

switch ( currentOpCode ) {
case 0 :
multOp() ;
break ;
case 1 :
divOp() ;
break ;
case 2 :
MyPrint( "opCodeMethod(): opCode =s " + currentOpCode ) ;
subOp() ;
break ;
case 3 :
MyPrint( "opCodeMethod(): opCode =s " + currentOpCode ) ;
plusOp() ;
break ;
case 4 :
MyPrint( "Calling PowerOp method." );
MyPrint( "Case 4: the value of firstNum is " +
firstNum + " the value of secondNum is " +
secondNum ) ;
secondNumSet = true ;
powerOp() ;
break ;
case 5 :
break ;
default :
setResults() ;
firstNumSet = true ;
secondNum = "0.0" ;
dNum2 = 0.0 ;
pendingOp = false ;
opCode = 99 ;
MyPrint( "Case default: firstNum =s " + firstNum);
break ;
}

if ( !( opCode == 99 ) )
opCode = -1 ;

} /** ********** End of opCodeMethod() **************/

/** powerOp() - raises the first number to the power of the second */
private void powerOp() {
MyPrint( "1a- powerOp: The value of firstNum is " + firstNum +
" The value of secondNum is " + secondNum
+
" The value of answer is " + answer );
if ( opCode == 99 ) {
setResults() ;
}

if ( firstNumSet ) {

if ( pendingOp ) {
opCodeMethod() ;
pendingOp = false ;
secondNumSet = false ;
}
if ( secondNumSet ) {
MyPrint( "1b- powerOp: The value of firstNum is " + firstNum +
" The value of secondNum is " + secondNum
+
" The value of answer is " + answer );

secondNum = enterBox.getText() ;
convertNumsToDouble() ;
answer = Math.pow( dNum1 , dNum2 ) ;
setResults() ;
MyPrint( "1c- powerOp: The value of answer is " + answer +
" The value of opCode is " + opCode );
}
}
else {
if ( checkFirstNum() ) {
MyPrint( "1d- powerOp: The value of answer is " + answer +
" The value of opCode is " + opCode );
pendingOpCode = 4 ;
}
}
opCode = 4 ;
} /** ********** End of powerOp() **************/

/**
* divOp()
* Version 1.1
* Changed 9/10/2003 - Fixed chained operation errors
*/
private void multOp() {

if ( pendingOp ) {
MyPrint( "1a- multOp(): opCode is " + opCode + " The value of firstNum is " +

firstNum );
opCodeMethod() ;
opCode = -1 ;
}

if ( !firstNumSet ) {
pendingOp = true ;

if ( opCode == 99 ) {
firstNum = "" + answer ;
firstNumSet = true ;
MyPrint( "1b- multOp(): opCode is " + opCode + " The value of firstNum is " +

firstNum );
}

if ( checkFirstNum() ) {
opCode = 0 ;
MyPrint( "1c- multOp(): opCode is " + opCode + " The value of firstNum is " +

firstNum );
pendingOpCode = 0 ;
}
}
else if ( opCode == 0 ) {
pendingOp = false ;
secondNum = enterBox.getText() ;
pendingOp = true ;
MyPrint( "2a- multOp(): opCode is " + opCode + " The value of secondNum is " +

secondNum );
if ( secondNum.equals( "" ) ) {
secondNum = "1.0" ;
MyPrint( "2b- multOp(): opCode is " + opCode + " The value of secondNum is " +

secondNum );
}
MyPrint( "3a- multOp(): opCode is " + opCode + " secondNum is " + secondNum ) ;
convertNumsToDouble() ;
answer = dNum1 * dNum2 ;
setResults() ;
MyPrint( "3b- multOp(): opCode is " + opCode + " The value of answer is " + answer

);
dNum1 = answer ;
secondNum = "0.0" ;
secondNumSet = true ;
}
else {
pendingOp = true ;
pendingOpCode = 0 ;
opCode = 0 ;
result = true ;
MyPrint( "3a- multOp(): opCode is " + opCode + " The value of answer is " + answer

);
}
} /** ********** End of multOp() **************/

/** /**
* divOp() - divides the two entered numbers and checks for a zero divisor
* Version 1.1
* Changed 9/10/2003 - Fixed chained operation errors
*/
private void divOp() {
MyPrint( "1a- divOp(): opCode is " + opCode + " firstNumSet =s " + firstNumSet );
if ( pendingOp ) {
MyPrint( "1aa- divOp(): opCode is " + opCode );
opCodeMethod() ;
opCode = -1 ;
}

if ( !firstNumSet ) {
pendingOp = true ;

if ( opCode == 99 ) {
firstNum = "" + answer ;
firstNumSet = true ;
MyPrint( "1b- divOp(): opCode is " + opCode + " The value of firstNum is " +

firstNum );
}

if ( checkFirstNum() ) {
MyPrint( "1c- divOp(): opCode is " + opCode + " The value of firstNum is " +

firstNum );
pendingOpCode = 1 ;
opCode = 1 ;
}
}
else if ( firstNumSet ) {
if ( pendingOp ) {
opCodeMethod() ;
opCode = 1 ;
}

secondNum = enterBox.getText() ;
MyPrint( "2a- divOp(): opCode is " + opCode + " firstNum is " +
firstNum + " secondNum is " + secondNum ) ;
if ( secondNum.equals( "" ) || opCode < 0 ) {
MyPrint( "2b- divOp(): opCode is " + opCode + " firstNum is " +
firstNum + " secondNum is " + secondNum ) ;
}
else {
convertNumsToDouble() ;
if (dNum2 != 0.0 ) {
answer = dNum1 / dNum2 ;
setResults() ;
MyPrint( "2- divOp(): opCode is " + opCode + " firstNum is " +
firstNum + " secondNum is " + secondNum ) ;
}
else {
JOptionPane.showMessageDialog( this, "The number " +
dNum2 + " cannot be used as a denometer" ,
"Attempted to Divide by Zero",
JOptionPane.ERROR_MESSAGE );
firstNumSet = false ;
firstNum = "" ;
opCode = -1 ;
}
}
opCode = 1 ;

}
//enterBox.setText( "" ) ;
result = true ;
} /** ********** End of divOp() **************/

/** subOp() - subtracts the second number from the first number
*
* Version 1.1
* Changed 9/10/2003 - Fixed chained operation errors
* */
private void subOp() {

if ( pendingOp ) {
MyPrint( "subOp() 1a: In pendingOp code. The opcode value is " + opCode ) ;
opCodeMethod() ;
opCode = 2 ;
pendingOp = true ;
pendingOpCode = 2 ;
}
else if( !firstNumSet ) {
firstNum = enterBox.getText() ;
pendingOp = true ;
pendingOpCode = 2 ;
opCode = 2 ;
firstNumSet = true ;
result = true ;
MyPrint( "1b- subOp()-checkFirstNum(): opCode is " + opCode + " The value of answer

is " + answer );
}
else if ( opCode == 2 ) {
pendingOp = false ;

if ( secondNum.equals( "0.0" ) ) {
firstNum = "" + answer ;
}

secondNum = enterBox.getText() ;
if ( secondNum.equals( "" ) ) {
secondNum = "0.0" ;
}
MyPrint( "2a- subOp(): opCode is " + opCode + " secondNum is " + secondNum ) ;
convertNumsToDouble() ;
answer = dNum1 - dNum2 ;
setResults() ;
MyPrint( "2b- subOp(): opCode is " + opCode + " The value of answer is " + answer

);
secondNum = "0.0" ;
opCode = -1 ;
secondNumSet = true ;
}
else {
pendingOp = true ;
pendingOpCode = 2 ;
opCode = 2 ;
result = true ;
MyPrint( "3a- subOp(): opCode is " + opCode + " The value of answer is " + answer

);
}
} /** ********** End of subOp() **************/

/**
* plusOp() - adds the two entered numbers
* Version 1.1
* Changed 9/10/2003 - Fixed chained operation errors
*/
private void plusOp() {

if ( pendingOp ) {
MyPrint( "subOp() 1a: In pendingOp code. The opcode value is " + opCode ) ;
opCodeMethod() ;
opCode = 3 ;
pendingOp = true ;
pendingOpCode = 3 ;
}
else if( !firstNumSet ) {
firstNum = enterBox.getText() ;
pendingOp = true ;
pendingOpCode = 3 ;
opCode = 3 ;
firstNumSet = true ;
result = true ;
MyPrint( "1b- plusOp()-checkFirstNum(): opCode is " + opCode + " The value of

answer is " + answer );
}
else if ( opCode == 3 ) {
pendingOp = false ;
MyPrint( "2aa- plusOp(): opCode is " + opCode + " secondNum is " + secondNum ) ;
if ( secondNum.equals( "0.0" ) ) {
firstNum = "" + answer ;
}

secondNum = enterBox.getText() ;
if ( secondNum.equals( "" ) ) {
secondNum = "0.0" ;
}
MyPrint( "2a- plusOp(): opCode is " + opCode + " secondNum is " + secondNum ) ;
convertNumsToDouble() ;
answer = dNum1 + dNum2 ;
setResults() ;
MyPrint( "2b- plusOp(): opCode is " + opCode + " The value of answer is " + answer

);
secondNum = "0.0" ;
opCode = -1 ;
secondNumSet = true ;
}
else {
pendingOp = true ;
pendingOpCode = 3 ;
opCode = 3 ;
result = true ;
MyPrint( "3a- plusOp(): opCode is " + opCode + " The value of answer is " + answer

);
}
} /** ********** End of plusOp() **************/

/** convertNumsToDouble() - converts numbers entered from string to double */
private void convertNumsToDouble() {
if ( !firstNum.equals( "" ) )
dNum1 = Double.parseDouble( firstNum ) ;
if ( !secondNum.equals( "" ) )
dNum2 = Double.parseDouble( secondNum ) ;
MyPrint( "convertNumsToDouble(): The value of dNum1 is " + dNum1 );
MyPrint( "convertNumsToDouble(): The value of dNum2 is " + dNum2 );

} /** ********** End of convertNumsToDouble() **************/

/** PlusMinus() - toggles the sign of the entered number */
private void PlusMinus() {
MyPrint( "PlusMinus: The value of enterBox is " + enterBox.getText() );

if ( !enterBox.getText().equals( "" ) ) {
answer = Double.parseDouble( enterBox.getText() ) * minusOne ;
MyPrint( "1a- PlusMinus: The value of answer is " + answer );
setResults() ;
}
else if ( !firstNum.equals( "" ) ) {
answer = Double.parseDouble( firstNum ) * minusOne ;
setResults() ;
MyPrint( "1b- PlusMinus: The value of firstNum is " + firstNum );
}
result = true ;

} /** ********** End of PlusMinus() **************/

/** MySqrt() - computes the square root of the entered number */
private void MySqrt() {
MyPrint( "1a- MySqrt(): opCode is " + opCode + " firstNum is " + firstNum ) ;
if ( opCode == 99 ) {
answer = Math.sqrt( answer ) ;
setResults() ;
}
else if ( !enterBox.getText().equals( "" ) ) {
MyPrint( "1b- MySqrt(): opCode is " + opCode + " firstNum is " + firstNum ) ;
if ( pendingOp )
opCodeMethod() ;
answer = Double.parseDouble( enterBox.getText() ) ;
answer = Math.sqrt( answer ) ;
setResults() ;
}
else if ( !firstNum.equals( "" ) ) {
MyPrint( "1c- MySqrt(): opCode is " + opCode + " firstNum is " + firstNum ) ;
answer = Double.parseDouble( firstNum ) ;
answer = Math.sqrt( answer ) ;
setResults() ;
}
//opCode = -1 ;

} /** ********** End of MySqrt() **************/

/** OneDivX() - computes the value of one divided by the entered number */
private void OneDivX() {
MyPrint( "1a- OneDivX(): opCode is " + opCode + " firstNum is " + firstNum ) ;
if ( opCode == 99 ) {
answer = ( 1.0 / answer ) ;
setResults() ;
}
else if ( !enterBox.getText().equals( "" ) ) {
answer = Double.parseDouble( enterBox.getText() ) ;
answer = ( 1.0 / answer ) ;
setResults() ;
}
else if ( firstNumSet ) {
answer = Double.parseDouble( firstNum ) ;
answer = ( 1.0 / answer ) ;
setResults() ;
}
}
/** ********** End of OneDivX() **************/

/** sysExit() - causes the application to exit */
private void sysExit() {
System.exit( 0 );

} /** ********** End of sysExit() **************/

/** MyPrint() - toggles debug aid on or off*/
private void MyPrint( String str ) {
if ( myDiag )
System.out.println( str );

} /** ********** End of MyPrint() **************/

/** main() */
public static void main( String args[] ) {

final MyCalc app = new MyCalc () ; /** creates an instance of MyCalc */