Re: URGENT Help With Scientific Calculator!

From: Maria Laura Re (laurare_at_rocketmail.com)
Date: 12/14/03

  • Next message: Anil Sharma: "Re: Color of Disabled Checkboxes" 
    Date: 14 Dec 2003 07:49:21 -0800

    I worked a little bit more on the code, I pasted the updated version
    below. I still need help with the rest of the actions for the
    scientific buttons.

    I would really appreciate your help,

    -Maria

    import java.awt.*;
    import java.awt.event.*;
    import javax.swing.*;
    import javax.swing.border.*;

    public class calculator extends JApplet implements ActionListener{
      private JButton[] buttons;
      private String[] ops = {"CE", "/", "*", "-", ".", "+", "MEM", "MRC",
        "SIN", "TAN", "ASIN", "COS","ATAN","X","SQRT","EXP","PI",
        "%", "="};
      private JLabel output, blank;
      private Container contentP;
      private String operation;
      private double number1, number2, result;
      private boolean cleared = false;
      
      public void init(){
        contentP = getContentPane();
        JPanel container = new JPanel();
        container.setLayout(new FlowLayout(FlowLayout.CENTER));
        output = new JLabel("");
        output.setBorder(new MatteBorder(2, 2, 2, 2, Color.gray));
        output.setPreferredSize(new Dimension(1, 26));
        contentP.setBackground(Color.white);
        contentP.add("North", output);
        contentP.add("Center", container);
        
        blank = new JLabel(" ");
        container.add(blank);
        
        buttons = new JButton[29];
        for (int i = 0; i < 10; ++i){
          buttons[i] = new JButton((new Integer(i)).toString());
        }
        for (int i = 10; i < buttons.length; ++i){
          buttons[i] = new JButton(ops[i - 10]);
        }
        for (int i = 0; i < buttons.length; ++i){
          buttons[i].addActionListener(this);
        }
        JButton[] alignButtons = new JButton[29];
        alignButtons[0] = buttons[10]; // CE
        alignButtons[4] = buttons[11]; // /
        alignButtons[8] = buttons[12]; // *
        alignButtons[12] = buttons[13]; // -
        alignButtons[1] = buttons[7]; // 7
        alignButtons[2] = buttons[8]; // 8
        alignButtons[3] = buttons[9]; // 9
        alignButtons[5] = buttons[4]; // 4
        alignButtons[6] = buttons[5]; // 5
        alignButtons[7] = buttons[6]; // 6
        alignButtons[9] = buttons[1]; // 1
        alignButtons[10] = buttons[2]; // 2
        alignButtons[11] = buttons[3]; // 3
        alignButtons[13] = buttons[0]; // 0
        for (int i = 14; i < buttons.length; ++i){
          alignButtons[i] = buttons[i];
        } addButtons(alignButtons, container);
      } // init()

      void addButtons(JButton[] btns, Container cont){

        for (int i = 0; i < btns.length; ++i){
          cont.add(btns[i]);
        }
      }

      public static void main(String args[]){
        JFrame applicationWindow = new JFrame("calculator");
        applicationWindow.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        calculator appletObject = new calculator();
        applicationWindow.getContentPane().add(appletObject,
    BorderLayout.CENTER);
        applicationWindow.setBounds(0,0, 500, 200);
        applicationWindow.setVisible(true);
        appletObject.init();
        appletObject.start();
      } // main()

      public void actionPerformed(ActionEvent ae){
        JButton but = (JButton)ae.getSource();
        String op = but.getText();
        
        if (op.equals(".")){
          String temp = output.getText();
          if(temp.indexOf('.') == -1){
            output.setText(output.getText() + op);
          }
        }
        else if(op.equals("CE")){
          output.setText("");
          operation = "";
          number1 = 0.0;
          number2 = 0.0;
        }
        else if("+-*/".indexOf(op) != -1){
          operation = op;
          try{
            number1 = Double.parseDouble(output.getText());
          }
          catch(Exception e){
            e.printStackTrace();
            number1 = 0.0;
          }
          finally{
            cleared = true;
          }
        }
        else if(op.equals("=")){
          try{
            number2 = Double.parseDouble(output.getText());
          }
          catch(Exception e){
            e.printStackTrace();
            number2 = 0.0;
          }
          if(operation.equals("+")){
            result = number1 + number2;
          }
          else if(operation.equals("-")){
            result = number1 - number2;
          }
          else if(operation.equals("*")){
            result = number1 * number2;
          }
          else if(operation.equals("/")){
            result = number1 / number2;
          }
          output.setText(String.valueOf(result));
          cleared = true;
          operation = "";
        }
        else{
          if(cleared == true){
            output.setText("");
            cleared = false;
          }
          output.setText(output.getText() + but.getText());
        }
      }
    }

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