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Source code for a simple java programming calculator.

Note I am completely new to java. I need examples of source code for a simple calculator applet, yes it is an homework assigmnent. I have set the layout for the button of the calculator but I do not know how to make the work. For this assignment have to us the ActionListener method with the code provided:
//keep as original
import java.awt.*;
import java.applet.*;
import java.awt.event.*;

public class Calculator extends Applet implements ActionListener
{
      String myBuffer;
      String firstBuffer;
      String secondBuffer;

String operation;

int result;
String passtoresult;

      Panel row1 = new Panel();
      Panel row2 = new Panel();
      Panel row3 = new Panel();

      Label titleLabel = new Label("Calculator", Label.CENTER);
      TextField resultField = new TextField(15);

      Button one = new Button ("1");
      Button zero = new Button ("0");
      Button two = new Button ("2");
      Button three = new Button ("3");
      Button four = new Button ("4");
      Button five = new Button ("5");
      Button six = new Button ("6");
      Button seven = new Button ("7");
      Button eight = new Button ("8");
      Button nine = new Button ("9");
      Button add = new Button ("add");
      Button subtract = new Button ("subtract");
      Button multiply = new Button ("multiply");
      Button divide = new Button ("divide");
      Button equals = new Button ("equals");

      public void init()
      {
            myBuffer="";
            firstBuffer="";
            secondBuffer="";

            one.addActionListener(this);
            zero.addActionListener(this);
            two.addActionListener(this);
            three.addActionListener(this);
            four.addActionListener(this);
            five.addActionListener(this);
            six.addActionListener(this);
            seven.addActionListener(this);
            eight.addActionListener(this);
            nine.addActionListener(this);
            add.addActionListener(this);
            subtract.addActionListener(this);
            multiply.addActionListener(this);
            divide.addActionListener(this);
            equals.addActionListener(this);

            setBackground(Color.white);

            GridLayout line1 = new GridLayout(2,1,100,10);
            row1.setLayout(line1);
            row1.add(titleLabel);row1.add(resultField);
            add(row1);

            GridLayout line2 = new GridLayout(3,4,2,2);
            row2.setLayout(line2);
            row2.add(one);row2.add(two);
            row2.add(three);row2.add(four);row2.add(five);
            row2.add(six);row2.add(seven);row2.add(eight);row2.add(nine);
row2.add(zero);
            add(row2);

            GridLayout line3 = new GridLayout(3,2,2,2);
            row3.setLayout(line3);
            row3.add(add);
            row3.add(subtract);
            row3.add(multiply);
            row3.add(divide);
            row3.add(equals);
            add(row3);

      }


      public void actionPerformed(ActionEvent event)
      {
            //if (event.getSource() == zero)
            //......add code here otherwise your compiler will complain


      }
}
please help

ASKER CERTIFIED SOLUTION

mmuruganandam

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mmuruganandam

If that link doesn't work, then copy paste the url and enter to get the page.

there is some problem with the geocities.

zzynx

1) As long a digits are pressed: display them in the result
2) When + or - is pressed, store the entered value before the + or - in an int/double,
store the operator (+ or -)
3) When they press a digit again show it in the result field
4) As long a digits are pressed: display them in the result
5) When they press =, store the entered value before the = in another int/double
Perform: variable1 operator variable2
6) Show the result in the result field

mmuruganandam

Here is another applet calculator with source code.

http://www.idoi.com/Java/Calculator.html

Regards,
Muruga

qwert1515

/*Qwert1515
*Caculator.java
*Creates a graphical caculator
*5/7/04
*/

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
//Caculator Class
public class Calculator extends JFrame implements ActionListener
{
public static final int WIDTH = 150;
public static final int HEIGHT = 320;
      private JTextField inputOutputField;
      private String action = "blank";
      private double value1 = 0;
private double value2 = 0;
private double memory1 =0.0;
private double memory2 =0.0;
//Creates a caculator Object and sets it visible
public static void main(String[] args)
{
Calculator calc = new Calculator();
calc.setVisible(true);
}

public Calculator()
{
setSize(WIDTH, HEIGHT);

addWindowListener(new WindowDestroyer());
setTitle("Caculator");
Container contentPane = getContentPane();
contentPane.setBackground(Color.lightGray );
contentPane.setLayout(new FlowLayout());
JPanel textPanel = new JPanel();
textPanel.setBackground(Color.blue);
textPanel.setLayout(new FlowLayout());
inputOutputField = new JTextField("", 12);
inputOutputField.setBackground(Color.white);
textPanel.add(inputOutputField);
contentPane.add(textPanel, BorderLayout.CENTER);
//Adds buttons to the caculators face
JButton buttonOne = new JButton("1");
buttonOne.addActionListener(this);
contentPane.add(buttonOne);

JButton buttonTwo = new JButton("2");
buttonTwo.addActionListener(this);
contentPane.add(buttonTwo);

JButton buttonThree = new JButton("3");
buttonThree.addActionListener(this);
contentPane.add(buttonThree);

JButton buttonFour = new JButton("4");
buttonFour.addActionListener(this);
contentPane.add(buttonFour);

JButton buttonFive = new JButton("5");
buttonFive.addActionListener(this);
contentPane.add(buttonFive);

JButton buttonSix = new JButton("6");
buttonSix.addActionListener(this);
contentPane.add(buttonSix);

     JButton buttonSeven = new JButton("7");
buttonSeven.addActionListener(this);
contentPane.add(buttonSeven);

JButton buttonEight = new JButton("8");
buttonEight.addActionListener(this);
contentPane.add(buttonEight);

JButton buttonNine = new JButton("9");
buttonNine.addActionListener(this);
contentPane.add(buttonNine);

JButton buttonZero = new JButton("0");
buttonZero.addActionListener(this);
contentPane.add(buttonZero);

JButton buttonDec = new JButton(".");
buttonDec.addActionListener(this);
contentPane.add(buttonDec);

JButton buttonClear = new JButton("C");
buttonClear.addActionListener(this);
contentPane.add(buttonClear);

JButton buttonAdd = new JButton("+");
buttonAdd.addActionListener(this);
contentPane.add(buttonAdd);

JButton buttonSub = new JButton("-");
buttonSub.addActionListener(this);
contentPane.add(buttonSub);

JButton buttonMult = new JButton("*");
buttonMult.addActionListener(this);
contentPane.add(buttonMult);

JButton buttonDiv = new JButton("/");
buttonDiv.addActionListener(this);
contentPane.add(buttonDiv);

JButton buttonEqu = new JButton("=");
buttonEqu.addActionListener(this);
contentPane.add(buttonEqu);

JButton memoneplusButton = new JButton("M1+");
     memoneplusButton.addActionListener(this);
contentPane.add(memoneplusButton);

JButton memtwoplusButton = new JButton("M2+");
memtwoplusButton.addActionListener(this);
contentPane.add(memtwoplusButton);

JButton mr1Button = new JButton("MR1");
mr1Button.addActionListener(this);
contentPane.add(mr1Button);

JButton mr2Button = new JButton("MR2");
mr2Button.addActionListener(this);
contentPane.add(mr2Button);

}
//Preforms the action when each button is pressed
public void actionPerformed(ActionEvent e)
{
String currentText = inputOutputField.getText();

Container contentPane = getContentPane();

            if(e.getActionCommand().equals("="))
            {
                  value2 = Double.parseDouble(currentText);
                  inputOutputField.setText("");

                  if(action.equals("add"))
                  {
                        action = "blank";
                        inputOutputField.setText(value1 + value2 + "");
                  }
                  else if(action.equals("sub"))
                  {
                        action = "blank";
                        inputOutputField.setText(value1 - value2 + "");
                  }
                  else if(action.equals("mult"))
                  {
                        action = "blank";
                        inputOutputField.setText(value1 * value2 + "");
                  }
                  else if(action.equals("div"))
                  {
                        action = "blank";
                        inputOutputField.setText(value1 / value2 + "");
                  }


                  else
                  {
                        if(currentText.length() > 0)
                        inputOutputField.setText(currentText);
                        else
                        inputOutputField.setText("");
                  }

            }

            else if(e.getActionCommand().equals("+"))
            {
                  action = "add";
                  value1 = Double.parseDouble(currentText);
                  inputOutputField.setText("");
            }
            else if(e.getActionCommand().equals("-"))
            {
                  action = "sub";
                  value1 = Double.parseDouble(currentText);
                  inputOutputField.setText("");
            }
            else if(e.getActionCommand().equals("*"))
            {
                  action = "mult";
                  value1 = Double.parseDouble(currentText);
                  inputOutputField.setText("");
            }
            else if(e.getActionCommand().equals("/"))
            {
                  action = "div";
                  value1 = Double.parseDouble(currentText);
                  inputOutputField.setText("");
            }
            else if(e.getActionCommand().equals("C"))
            {
                  inputOutputField.setText("");
            }
            else if(e.getActionCommand().equals("M1+"))
            {
                  memory1 = Double.parseDouble(currentText);
                  inputOutputField.setText("");
            }
            else if(e.getActionCommand().equals("M2+"))
            {
                  memory2 = Double.parseDouble(currentText);
                  inputOutputField.setText("");
            }

            else if(e.getActionCommand().equals("MR1"))
            {
                  inputOutputField.setText(memory1 +"");
            }
            else if(e.getActionCommand().equals("MR2"))
            {
                  inputOutputField.setText(memory2 +"");
            }
            else if(action.equals("."))
                  {
                        action = "blank";
                        inputOutputField.setText(currentText+=".");
                  }

      else
     inputOutputField.setText(currentText += e.getActionCommand());

}

}