Thread: how do I add Action Listener to my code to make the calculator work

here is the code i already have made;

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


public class EX_7_2 extends JFrame
{
public EX_7_2()
{
setLayout(new BorderLayout(5, 10));

// create p1
JPanel p1 = new JPanel();
p1.setLayout(new BorderLayout(5, 10));

p1.add(new JTextField(), BorderLayout.NORTH);
JPanel p3 = new JPanel();
p3.setLayout(new GridLayout(1, 3, 5, 5));
JButton btBackspace = new JButton ("Backspace");
btBackspace.setBackground(Color.WHITE);
btBackspace.setForeground(Color.RED);

JButton btCE = new JButton ("CE");
btCE.setBackground(Color.WHITE);
btCE.setForeground(Color.RED);

JButton btC = new JButton ("C");
btC.setBackground(Color.WHITE);
btC.setForeground(Color.RED);

p3.add(btBackspace);
p3.add(btCE);
p3.add(btC);

p1.add(p3, BorderLayout.CENTER);



// create p4

JPanel p2 = new JPanel();
p2.setLayout(new GridLayout(4, 3, 5, 5));

int num;
for (int iRow = 3; iRow>0; iRow--)
{
for (int iCol = 1; iCol<4; iCol++)
{
num = 3*(iRow-1) + iCol;

JButton btBody = new JButton("" + num);
btBody.setBackground(Color.WHITE);
btBody.setForeground(Color.BLUE);
p2.add(btBody);
}
}

JButton btZero = new JButton ("0");
btZero.setBackground(Color.WHITE);
btZero.setForeground(Color.BLUE);

JButton btPlusMinus = new JButton ("+/-");
btPlusMinus.setBackground(Color.WHITE);
btPlusMinus.setForeground(Color.BLUE);

JButton btDot = new JButton (".");
btDot.setBackground(Color.WHITE);
btDot.setForeground(Color.BLUE);

p2.add(btZero);
p2.add(btPlusMinus);
p2.add(btDot);


JPanel p5 = new JPanel();
p5.setLayout(new GridLayout(4, 2, 5, 5));

JButton btBack = new JButton ("/");
btBack.setBackground(Color.WHITE);
btBack.setForeground(Color.RED);

JButton btsprt = new JButton ("sprt");
btsprt.setBackground(Color.WHITE);
btsprt.setForeground(Color.BLUE);

JButton btStar = new JButton ("*");
btStar.setBackground(Color.WHITE);
btStar.setForeground(Color.RED);

JButton btPercentage = new JButton ("%");
btPercentage.setBackground(Color.WHITE);
btPercentage.setForeground(Color.BLUE);

JButton btMinus = new JButton ("-");
btMinus.setBackground(Color.WHITE);
btMinus.setForeground(Color.RED);

JButton btOnex = new JButton ("1/x");
btOnex.setBackground(Color.WHITE);
btOnex.setForeground(Color.BLUE);

JButton btPlus = new JButton ("+");
btPlus.setBackground(Color.WHITE);
btPlus.setForeground(Color.RED);

JButton btEquals = new JButton ("=");
btEquals.setBackground(Color.WHITE);
btEquals.setForeground(Color.RED);

p5.add(btBack);
p5.add(btsprt);
p5.add(btStar);
p5.add(btPercentage);
p5.add(btMinus);
p5.add(btOnex);
p5.add(btPlus);
p5.add(btEquals);

JPanel p4 = new JPanel();
p4.setLayout(new BorderLayout(5, 10));
p4.add(p2, BorderLayout.CENTER);
p4.add(p5, BorderLayout.EAST);

add(p1, BorderLayout.NORTH );
add(p4, BorderLayout.CENTER);
}


public static void main(String[] args) {

EX_7_2 frame = new EX_7_2();
frame.setTitle("Calculator");
frame.setSize(350, 375);
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOS E);
frame.setVisible(true);
}
}

google "java actionlistener", it's the first result

I HAVE LOOKED AT THE TUTORIAL BUT I STILL DON'T UNDERSTAND

Post your code correctly. Give your variables better names. Don't shout. Describe exactly what you don't understand.

We can't do a Vulcan mind meld and infuse you with total Java consciousness. We need to know specifically what you need help with.

Hi, i know that i need ;

public void actionPerformed(ActionEvent e) {

}

how i don't know how to give each individual number in the calculator a action so that the number appear.

Sorry to Mr GregBrannon, i was typing without realizing i had caps lock on and sent the post without realizing.

I don't see your number buttons, but if you have them, then you'd add an ActionListener to each button, perhaps the same ActionListener. For example, if you had a "5" button with a better name, like fiveButton, then you'd add an action listener to it:

fiveButton.addActionListener( al );

where, 'al', is the ActionListener that contains the desired actionPerformed() method.

i used the following code to create my number 1 to 9
JPanel p2 = new JPanel();
p2.setLayout(new GridLayout(4, 3, 5, 5));

int num;
for (int iRow = 3; iRow>0; iRow--)
{
for (int iCol = 1; iCol<4; iCol++)
{
num = 3*(iRow-1) + iCol;

JButton btBody = new JButton("" + num);
btBody.setBackground(Color.WHITE);
btBody.setForeground(Color.BLUE);
p2.add(btBody);
}
}

but not sure if your piece of code will help me.

Please post your code correctly.

how do i add my code correctly

See the top of Post #2 or the bottom of Post #8.

do you want me to add all of the code i have done;

here is my code;

/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package welcomegui;

/**
*
* @author am13aeg
*/
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;

public class EX_7_2 extends JFrame
{
public EX_7_2()
{
setLayout(new BorderLayout(5, 10));

// create p1
JPanel p1 = new JPanel();
p1.setLayout(new BorderLayout(5, 10));

p1.add(new JTextField(), BorderLayout.NORTH);
JPanel p3 = new JPanel();

p3.setLayout(new GridLayout(1, 3, 5, 5));
JButton btBackspace = new JButton ("Backspace");
btBackspace.setBackground(Color.WHITE);
btBackspace.setForeground(Color.RED);

JButton btCE = new JButton ("CE");
btCE.setBackground(Color.WHITE);
btCE.setForeground(Color.RED);

JButton btC = new JButton ("C");
btC.setBackground(Color.WHITE);
btC.setForeground(Color.RED);

p3.add(btBackspace);
p3.add(btCE);
p3.add(btC);

p1.add(p3, BorderLayout.CENTER);



// create p4

JPanel p2 = new JPanel();
p2.setLayout(new GridLayout(4, 3, 5, 5));

int num;
for (int iRow = 3; iRow>0; iRow--)
{
for (int iCol = 1; iCol<4; iCol++)
{
num = 3*(iRow-1) + iCol;

JButton btBody = new JButton("" + num);
btBody.setBackground(Color.WHITE);
btBody.setForeground(Color.BLUE);
p2.add(btBody);
}
}

JButton btZero = new JButton ("0");
btZero.setBackground(Color.WHITE);
btZero.setForeground(Color.BLUE);

JButton btPlusMinus = new JButton ("+/-");
btPlusMinus.setBackground(Color.WHITE);
btPlusMinus.setForeground(Color.BLUE);

JButton btDot = new JButton (".");
btDot.setBackground(Color.WHITE);
btDot.setForeground(Color.BLUE);

p2.add(btZero);
p2.add(btPlusMinus);
p2.add(btDot);


JPanel p5 = new JPanel();
p5.setLayout(new GridLayout(4, 2, 5, 5));

JButton btBack = new JButton ("/");
btBack.setBackground(Color.WHITE);
btBack.setForeground(Color.RED);

JButton btsprt = new JButton ("sprt");
btsprt.setBackground(Color.WHITE);
btsprt.setForeground(Color.BLUE);

JButton btStar = new JButton ("*");
btStar.setBackground(Color.WHITE);
btStar.setForeground(Color.RED);

JButton btPercentage = new JButton ("%");
btPercentage.setBackground(Color.WHITE);
btPercentage.setForeground(Color.BLUE);

JButton btMinus = new JButton ("-");
btMinus.setBackground(Color.WHITE);
btMinus.setForeground(Color.RED);

JButton btOnex = new JButton ("1/x");
btOnex.setBackground(Color.WHITE);
btOnex.setForeground(Color.BLUE);

JButton btPlus = new JButton ("+");
btPlus.setBackground(Color.WHITE);
btPlus.setForeground(Color.RED);

JButton btEquals = new JButton ("=");
btEquals.setBackground(Color.WHITE);
btEquals.setForeground(Color.RED);

p5.add(btBack);
p5.add(btsprt);
p5.add(btStar);
p5.add(btPercentage);
p5.add(btMinus);
p5.add(btOnex);
p5.add(btPlus);
p5.add(btEquals);

JPanel p4 = new JPanel();
p4.setLayout(new BorderLayout(5, 10));
p4.add(p2, BorderLayout.CENTER);
p4.add(p5, BorderLayout.EAST);

add(p1, BorderLayout.NORTH );
add(p4, BorderLayout.CENTER);
}




public static void main(String[] args) {

EX_7_2 frame = new EX_7_2();
frame.setTitle("Calculator");
frame.setSize(350, 375);
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOS E);
frame.setVisible(true);

}
}

--- Update ---

i do not get what you mean my add code tag, this is the first time i using a forum

What don't you understand about the instructions (and his note) that Norm gave in Post #8?

i have never heard of code tags have never used them therefore i dont know what i need to do to add the code tags

her is the full code;

 
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
 
public class EX_7_2 extends JFrame 
    {
        public EX_7_2()
        {
            setLayout(new BorderLayout(5, 10));
 
            // create p1
            JPanel p1 = new JPanel();
            p1.setLayout(new BorderLayout(5, 10));
 
          p1.add(new JTextField(), BorderLayout.NORTH);
                    JPanel p3 = new JPanel();
 
         p3.setLayout(new GridLayout(1, 3, 5, 5));
         JButton btBackspace = new JButton ("Backspace");
         btBackspace.setBackground(Color.WHITE);
         btBackspace.setForeground(Color.RED);
 
         JButton btCE = new JButton ("CE");
         btCE.setBackground(Color.WHITE);
         btCE.setForeground(Color.RED);
 
         JButton btC = new JButton ("C");
         btC.setBackground(Color.WHITE);
         btC.setForeground(Color.RED);
 
          p3.add(btBackspace);
          p3.add(btCE);
          p3.add(btC);
 
          p1.add(p3, BorderLayout.CENTER);
 
 
 
          // create p4
 
          JPanel p2 = new JPanel();
          p2.setLayout(new GridLayout(4, 3, 5, 5));  
 
          int num;
          for (int iRow = 3; iRow>0; iRow--)
          {
              for (int iCol = 1; iCol<4; iCol++)
              {
                  num = 3*(iRow-1) + iCol;
 
                  JButton btBody = new JButton("" + num);
                  btBody.setBackground(Color.WHITE);
                  btBody.setForeground(Color.BLUE);
                  p2.add(btBody);
              }           
          }
 
         JButton btZero = new JButton ("0");
         btZero.setBackground(Color.WHITE);
         btZero.setForeground(Color.BLUE);
 
         JButton btPlusMinus = new JButton ("+/-");
         btPlusMinus.setBackground(Color.WHITE);
         btPlusMinus.setForeground(Color.BLUE);
 
         JButton btDot = new JButton (".");
         btDot.setBackground(Color.WHITE);
         btDot.setForeground(Color.BLUE);
 
         p2.add(btZero);
          p2.add(btPlusMinus);
          p2.add(btDot);
 
 
         JPanel p5 = new JPanel();
         p5.setLayout(new GridLayout(4, 2, 5, 5));
 
         JButton btBack = new JButton ("/");
         btBack.setBackground(Color.WHITE);
         btBack.setForeground(Color.RED);
 
         JButton btsprt = new JButton ("sprt");
         btsprt.setBackground(Color.WHITE);
         btsprt.setForeground(Color.BLUE);
 
         JButton btStar = new JButton ("*");
         btStar.setBackground(Color.WHITE);
         btStar.setForeground(Color.RED);
 
         JButton btPercentage = new JButton ("%");
         btPercentage.setBackground(Color.WHITE);
         btPercentage.setForeground(Color.BLUE);
 
         JButton btMinus = new JButton ("-");
         btMinus.setBackground(Color.WHITE);
         btMinus.setForeground(Color.RED);
 
         JButton btOnex = new JButton ("1/x");
         btOnex.setBackground(Color.WHITE);
         btOnex.setForeground(Color.BLUE);
 
         JButton btPlus = new JButton ("+");
         btPlus.setBackground(Color.WHITE);
         btPlus.setForeground(Color.RED);
 
         JButton btEquals = new JButton ("=");
         btEquals.setBackground(Color.WHITE);
         btEquals.setForeground(Color.RED);
 
         p5.add(btBack);
           p5.add(btsprt);
            p5.add(btStar);
             p5.add(btPercentage);
              p5.add(btMinus);
               p5.add(btOnex);
                p5.add(btPlus);
                 p5.add(btEquals);
 
                 JPanel p4 = new JPanel();
                 p4.setLayout(new BorderLayout(5, 10));
                 p4.add(p2, BorderLayout.CENTER);                
      p4.add(p5, BorderLayout.EAST);          
 
      add(p1, BorderLayout.NORTH );
      add(p4, BorderLayout.CENTER);
        }
 
 
 
 
public static void main(String[] args) {
 
        EX_7_2 frame = new EX_7_2();
        frame.setTitle("Calculator");
        frame.setSize(350, 375);
              frame.setLocationRelativeTo(null);
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
 
}
}

Ahhhh. Thank you. (and Norm for making it clear)

Breaking out your number button code:

          int num;
          for (int iRow = 3; iRow>0; iRow--)
          {
              for (int iCol = 1; iCol<4; iCol++)
              {
                  num = 3*(iRow-1) + iCol;
 
                  JButton btBody = new JButton("" + num);
                  btBody.setBackground(Color.WHITE);
                  btBody.setForeground(Color.BLUE);
                  p2.add(btBody);
              }           
          }

A number of buttons are being made that are all called btBody, and they're local to the inner for loop. Since they're all assigned to btBody, there's really only one button. Those 2 conditions (one button and it is local) are working against you. You should create an array of JButtons - giving each one a separate name and identity - and the array of JButtons should be declared as an instance variable rather than a local variable.

Revise your code so that separate number buttons are created.

is that the only way, it it possible to add the actionlistener without removing the the code.

--- Update ---

norm how would i do that can you give me some help or an example code please

--- Update ---

can anyone help with the problem please.

Norm how do i create an instance for my code, i'm not quite familiar with this yet, could you please show me.

could you give the the whole code which i will allow the number number to work please.