Check Boxes

[Jodi Clackers]

hello ppl....having trouble with the check boxes in this code. I've never attempted to do this before, prolly why i have a 'fumbling around in the dark' feeling.

Any feedback would be muchly appreciated =0)

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

public class extra extends Frame implements ActionListener
{
private TextField num1, num2, num3, num4, num5, num6, num7, num8, num9, num10;
private Label L1, L2, L3, L4, L5, L6, L7, L8, name, answer;
private Button calc, print, clear, exit;
public double final_answer;
    private MessageBox msg;
    private JCheckBox ch1, ch2,ch3, ch4, ch5, ch6,ch7, ch8; 
    
public extra()
{

  ActionListener cblistener = new CheckBoxListener(); 
 
      ch1 = new JCheckBox("L1",true);
      ch2 = new JCheckBox("L2",true);
      ch3 = new JCheckBox("L3",true);
      ch4 = new JCheckBox("L4",true);
      ch5 = new JCheckBox("L5",true);
      ch6 = new JCheckBox("L6",true);
      ch7 = new JCheckBox("L7",true);
      ch8 = new JCheckBox("L8",true);
      
      
 
 
      ch1.addActionListener(cblistener);
      ch2.addActionListener(cblistener);
      ch3.addActionListener(cblistener);
      ch4.addActionListener(cblistener);
      ch5.addActionListener(cblistener);
      ch6.addActionListener(cblistener);
      ch7.addActionListener(cblistener);
      ch8.addActionListener(cblistener);
      
 


setSize(800,500);
setLayout(new FlowLayout(FlowLayout.RIGHT));

L1=new Label ("     CB-CAT5E-1 1M CAT.5E UTP CABLE RJ45M");
num1=new TextField(5);


L2=new Label ("     CB-CAT5E-10 10M CAT.5E UTP CABLE RJ45M");
num2=new TextField(15);
num2.setEditable(false);
 
L3=new Label("      CB-CAT6-1 1M AT6 UTP CABLE RJ45M");
num3=new TextField(15);
num3.setEditable(false);

L4=new Label("      CB-CAT6-10 10M CAT6 UTP CABLE RJ45M");
num4=new TextField(15);
num4.setEditable(false);

L5=new Label("      CB-CAT5ECS-2 2M CAT.5E UTP CROSSOVER CABLE RJ45M");
num5=new TextField(15);
num5.setEditable(false);

L6=new Label("      CB-CAT5ECS-10 10M CAT.5E UTP CROSSOVER CABLE RJ45M");
num6=new TextField(15);
num6.setEditable(false);

L7=new Label("      CB-CAT6CS-2 2M CAT6 UTP CROSSOVER CABLE RJ45M");                
num7=new TextField(15);
num7.setEditable(false);

L8=new Label("      CB-CAT6CS-10 10M CAT6 UTP CROSSOVER CABLE RJ45M");                      
num8=new TextField(15);
num8.setEditable(false);

setLayout(new FlowLayout(FlowLayout.LEFT));
 
name=new Label("Customer Name:");
num9=new TextField(15);
num9.setEditable(false);

answer=new Label("The cost of your purchase is:     ");
num10=new TextField(15);
num10.setEditable(false);

calc=new Button("Calculate");
calc.addActionListener(this);
 
print=new Button("Print Cost");
calc.addActionListener(this);
 
clear=new Button("Clear");
clear.addActionListener(this);
 
exit=new Button ("Exit");
exit.addActionListener(this);

add(L1);
add(num1);
add(L2);
add(num2);
add(L3);
add(num3);
add(L4);
add(num4);
add(L5);
add(num5);
add(L6);
add(num6);
add(L7);
add(num7);
add(L8);
add(num8);
add(name);
add(num9);
add(answer);
add(num10);
add(calc);
add(print);
add(clear);
add(exit);
 


}

public void actionPerformed(ActionEvent e)
{  
DecimalFormat twoDigits = new DecimalFormat("0.00");
   if(e.getSource() == calc)
   {
      try{
        final_answer= Double.parseDouble(num1.getText()) + Double.parseDouble(num2.getText());
answer.setText(twoDigits.format(final_answer));          
      
     }
 catch(NumberFormatException nfe)
 {
   msg.setVisible(true);
         }  
   }
      if(e.getSource() == clear)
   {
      num1.setText("");
  num2.setText("");
  answer.setText("");
        }
      if(e.getSource() == exit)
        {
        System.exit(0);       
        }
}
public static void main(String args[]) 
{     
 extra e= new extra();
}
 
}  
 

[Dirk Schreckmann]

Moving this to the Swing / AWT / SWT / JFace forum...

[Craig Wood]

From your import statement it looks like you want to write a Swing (vis–a–vis AWT) application. It is recommended that we do not mix them; use either all AWT or all Swing. So the first change is to make everything a "J" component.

Writing GUI apps requires some learning about layout managers. If you'll read about the basic ones, viz, FlowLayout, BorderLayout and GridLayout, and learn to use them you can layout just about anything in your GUIs. Using a combination of layout managers is easy; just build one JPanel at a time.

This line is okay

    ActionListener cblistener = new CheckBoxListener(); 

as long as your CheckBoxListener class doesn't have any other methods in it that you need to call with the reference cblistener. Otherwise you would declare it

    CheckBoxListener cblistener = new CheckBoxListener(); 

Don't change ponies in mid–stream:

        ...
        setLayout(new FlowLayout(FlowLayout.RIGHT));
        ...
        setLayout(new FlowLayout(FlowLayout.LEFT));
        ...

import java.awt.*;
import java.awt.event.*;
import java.text.*;
import javax.swing.*;
 
public class Extra extends JFrame implements ActionListener
{
    private JTextField num1, num2, num3, num4, num5, num6, num7, num8, num9, num10;
    private JLabel L1, L2, L3, L4, L5, L6, L7, L8, name, answer;
    private JButton calc, print, clear, exit;
    public double final_answer;
//    private MessageBox msg;
    private JCheckBox ch1, ch2,ch3, ch4, ch5, ch6,ch7, ch8;
    DecimalFormat twoDigits;
 
    public Extra()
    { 
        twoDigits = new DecimalFormat("0.00");
        ActionListener cblistener = new CheckBoxListener(); 
 
        ch1 = new JCheckBox("L1",true);
        ch2 = new JCheckBox("L2",true);
        ch3 = new JCheckBox("L3",true);
        ch4 = new JCheckBox("L4",true);
        ch5 = new JCheckBox("L5",true);
        ch6 = new JCheckBox("L6",true);
        ch7 = new JCheckBox("L7",true);
        ch8 = new JCheckBox("L8",true);
 
        ch1.addActionListener(cblistener);
        ch2.addActionListener(cblistener);
        ch3.addActionListener(cblistener);
        ch4.addActionListener(cblistener);
        ch5.addActionListener(cblistener);
        ch6.addActionListener(cblistener);
        ch7.addActionListener(cblistener);
        ch8.addActionListener(cblistener);
//        setLayout(new FlowLayout(FlowLayout.RIGHT));
 
        L1=new JLabel (" CB-CAT5E-1 1M CAT.5E UTP CABLE RJ45M");
        num1=new JTextField(5);
 
        L2=new JLabel (" CB-CAT5E-10 10M CAT.5E UTP CABLE RJ45M");
        num2=new JTextField(15);
        num2.setEditable(false);
 
        L3=new JLabel(" CB-CAT6-1 1M AT6 UTP CABLE RJ45M");
        num3=new JTextField(15);
        num3.setEditable(false);
 
        L4=new JLabel(" CB-CAT6-10 10M CAT6 UTP CABLE RJ45M");
        num4=new JTextField(15);
        num4.setEditable(false);
 
        L5=new JLabel(" CB-CAT5ECS-2 2M CAT.5E UTP CROSSOVER CABLE RJ45M");
        num5=new JTextField(15);
        num5.setEditable(false);
 
        L6=new JLabel(" CB-CAT5ECS-10 10M CAT.5E UTP CROSSOVER CABLE RJ45M");
        num6=new JTextField(15);
        num6.setEditable(false);
 
        L7=new JLabel(" CB-CAT6CS-2 2M CAT6 UTP CROSSOVER CABLE RJ45M"); 
        num7=new JTextField(15);
        num7.setEditable(false);
 
        L8=new JLabel(" CB-CAT6CS-10 10M CAT6 UTP CROSSOVER CABLE RJ45M"); 
        num8=new JTextField(15);
        num8.setEditable(false);
 
//        setLayout(new FlowLayout(FlowLayout.LEFT));
 
        name=new JLabel("Customer Name:");
        num9=new JTextField(15);
        num9.setEditable(false);
 
        answer=new JLabel("The cost of your purchase is: ");
        num10=new JTextField(15);
        num10.setEditable(false);
 
        calc=new JButton("Calculate");
        calc.addActionListener(this);
 
        print=new JButton("Print Cost");
        calc.addActionListener(this);
 
        clear=new JButton("Clear");
        clear.addActionListener(this);
 
        exit=new JButton ("Exit");
        exit.addActionListener(this);
 
        JTextField[] fields = {
            num1, num2, num3, num4, num5, num6, num7, num8, num9, num10
        };
        JLabel[] labels = {
            L1, L2, L3, L4, L5, L6, L7, L8, name, answer
        };
        JPanel center = new JPanel(new GridLayout(0,1));
        JPanel p;
        for(int j = 0; j < fields.length; j++)
        {
            p = new JPanel();
            p.add(labels[j]);
            p.add(fields[j]);
            center.add(p);
        }
 
        JPanel result = new JPanel();
        result.add(name);
        result.add(num9);
        result.add(answer);
        result.add(num10);
 
        JPanel buttonPanel = new JPanel();
        buttonPanel.add(calc);
        buttonPanel.add(print);
        buttonPanel.add(clear);
        buttonPanel.add(exit);
 
        JPanel south = new JPanel(new GridLayout(0,1));
        south.add(result);
        south.add(buttonPanel);
 
        // JFrame methods
        getContentPane().add(center);
        getContentPane().add(south, BorderLayout.PAGE_END);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setSize(800,500);
        setLocation(100,100);
        setVisible(true);
    }
 
    public void actionPerformed(ActionEvent e)
    { 
        if(e.getSource() == calc)
        {
            try
            {
                final_answer= Double.parseDouble(num1.getText()) +
                              Double.parseDouble(num2.getText());
                answer.setText(twoDigits.format(final_answer)); 
            }
            catch(NumberFormatException nfe)
            {
//                msg.setVisible(true);
            } 
        }
        if(e.getSource() == clear)
        {
            num1.setText("");
            num2.setText("");
            answer.setText("");
        }
        if(e.getSource() == exit)
        {
            System.exit(0); 
        }
    }
 
    private class CheckBoxListener implements ActionListener
    {
        public void actionPerformed(ActionEvent e)
        {
        }
    }
 
    public static void main(String args[]) 
    { 
        Extra e= new Extra();
    }
}

[ September 05, 2004: Message edited by: Craig Wood ]