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Help on an applet

I'm trying to make an applet with checkboxes and it would have many different comibinations of if statements to get this done for the appropriate boxes checked, but I am faced with two problems. First, the if statements get really long because I have to indicate not only which box is checked, but also which one is not for it to work properly (at least from my way of doing it). Is there a way to reduce this?
Also, since the statements are really long, so is my CheckBoxListener class. Is there a way to make this a seprate class in order to make my applet class shorter and easier to read? Here's my code. By the way, any other pionters would be much obliged.

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

public class WarApplet extends JApplet {
JCheckBox englandButton = new JCheckBox("England");
JCheckBox franceButton = new JCheckBox("France");
JCheckBox russiaButton = new JCheckBox("Russia");
JCheckBox unitedStatesButton = new JCheckBox("United States");

JTextArea txt = new JTextArea("Please choose a country.",10, 10);

public void init() {
      englandButton.setSelected(false);
      franceButton.setSelected(false);
      russiaButton.setSelected(false);
      unitedStatesButton.setSelected(false);

      Container cp = getContentPane();

      JPanel checkPanel = new JPanel();
      checkPanel.setLayout(new GridLayout(0,1));
      checkPanel.add(englandButton);
      checkPanel.add(franceButton);
      checkPanel.add(russiaButton);
      checkPanel.add(unitedStatesButton);
      cp.add(checkPanel, BorderLayout.WEST);

      txt.setLineWrap(true);
      txt.setWrapStyleWord(true);
      txt.setEditable(false);
      cp.add(txt, BorderLayout.CENTER);

      englandButton.addItemListener(new CheckBoxListener());
      franceButton.addItemListener(new CheckBoxListener());
      russiaButton.addItemListener(new CheckBoxListener());
      unitedStatesButton.addItemListener(new CheckBoxListener());
}

class CheckBoxListener implements ItemListener {
      public void itemStateChanged(ItemEvent e) {
       if (englandButton.isSelected() &&
            !franceButton.isSelected() &&
            !russiaButton.isSelected() &&
            !unitedStatesButton.isSelected())
            txt.setText(WarInfo.info[0]);
       else if (!englandButton.isSelected() &&
              franceButton.isSelected() &&
              !russiaButton.isSelected() &&
              !unitedStatesButton.isSelected())
            txt.setText(WarInfo.info[1]);
       else if (!englandButton.isSelected() &&
              !franceButton.isSelected() &&
              russiaButton.isSelected() &&
              !unitedStatesButton.isSelected())
            txt.setText(WarInfo.info[2]);
       else if (!englandButton.isSelected() &&
              !franceButton.isSelected() &&
              !russiaButton.isSelected() &&
              unitedStatesButton.isSelected())
            txt.setText(WarInfo.info[3]);
       else if (englandButton.isSelected() &&
              franceButton.isSelected() &&
              russiaButton.isSelected() &&
              unitedStatesButton.isSelected())
            txt.setText(WarInfo.info[4]);
       else if (!englandButton.isSelected() &&
              franceButton.isSelected() &&
              !russiaButton.isSelected() &&
              unitedStatesButton.isSelected())
            txt.setText(WarInfo.info[5]);
       else if (!englandButton.isSelected() &&
              !franceButton.isSelected() &&
              russiaButton.isSelected() &&
              unitedStatesButton.isSelected())
            txt.setText(WarInfo.info[6]);
       else if (englandButton.isSelected() &&
              franceButton.isSelected() &&
              !russiaButton.isSelected() &&
              !unitedStatesButton.isSelected())
            txt.setText(WarInfo.info[7]);
       else if (englandButton.isSelected() &&
              !franceButton.isSelected() &&
              !russiaButton.isSelected() &&
              unitedStatesButton.isSelected())
            txt.setText(WarInfo.info[8]);
       else if (englandButton.isSelected() &&
              franceButton.isSelected() &&
              russiaButton.isSelected() &&
              !unitedStatesButton.isSelected())
            txt.setText(WarInfo.info[9]);
       else txt.setText("Please choose a country.");
      }
}

}

ASKER CERTIFIED SOLUTION

Mick Barry

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cini_gm

This way u can break this class. Save the two classes in the same directory and compile it

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

public class WarApplet extends JApplet {
JCheckBox englandButton = new JCheckBox("England");
JCheckBox franceButton = new JCheckBox("France");
JCheckBox russiaButton = new JCheckBox("Russia");
JCheckBox unitedStatesButton = new JCheckBox("United States");

JTextArea txt = new JTextArea("Please choose a country.",10, 10);

public void init() {
englandButton.setSelected(false);
franceButton.setSelected(false);
russiaButton.setSelected(false);
unitedStatesButton.setSelected(false);

Container cp = getContentPane();

JPanel checkPanel = new JPanel();
checkPanel.setLayout(new GridLayout(0,1));
checkPanel.add(englandButton);
checkPanel.add(franceButton);
checkPanel.add(russiaButton);
checkPanel.add(unitedStatesButton);
cp.add(checkPanel, BorderLayout.WEST);

txt.setLineWrap(true);
txt.setWrapStyleWord(true);
txt.setEditable(false);
cp.add(txt, BorderLayout.CENTER);

englandButton.addItemListener(new CheckBoxListener());
franceButton.addItemListener(new CheckBoxListener());
russiaButton.addItemListener(new CheckBoxListener());
unitedStatesButton.addItemListener(new CheckBoxListener());
}
}

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

public class CheckBoxListener implements ItemListener {
public void itemStateChanged(ItemEvent e) {
if (englandButton.isSelected() &&
!franceButton.isSelected() &&
!russiaButton.isSelected() &&
!unitedStatesButton.isSelected())
txt.setText(WarInfo.info[0]);
else if (!englandButton.isSelected() &&
franceButton.isSelected() &&
!russiaButton.isSelected() &&
!unitedStatesButton.isSelected())
txt.setText(WarInfo.info[1]);
else if (!englandButton.isSelected() &&
!franceButton.isSelected() &&
russiaButton.isSelected() &&
!unitedStatesButton.isSelected())
txt.setText(WarInfo.info[2]);
else if (!englandButton.isSelected() &&
!franceButton.isSelected() &&
!russiaButton.isSelected() &&
unitedStatesButton.isSelected())
txt.setText(WarInfo.info[3]);
else if (englandButton.isSelected() &&
franceButton.isSelected() &&
russiaButton.isSelected() &&
unitedStatesButton.isSelected())
txt.setText(WarInfo.info[4]);
else if (!englandButton.isSelected() &&
franceButton.isSelected() &&
!russiaButton.isSelected() &&
unitedStatesButton.isSelected())
txt.setText(WarInfo.info[5]);
else if (!englandButton.isSelected() &&
!franceButton.isSelected() &&
russiaButton.isSelected() &&
unitedStatesButton.isSelected())
txt.setText(WarInfo.info[6]);
else if (englandButton.isSelected() &&
franceButton.isSelected() &&
!russiaButton.isSelected() &&
!unitedStatesButton.isSelected())
txt.setText(WarInfo.info[7]);
else if (englandButton.isSelected() &&
!franceButton.isSelected() &&
!russiaButton.isSelected() &&
unitedStatesButton.isSelected())
txt.setText(WarInfo.info[8]);
else if (englandButton.isSelected() &&
franceButton.isSelected() &&
russiaButton.isSelected() &&
!unitedStatesButton.isSelected())
txt.setText(WarInfo.info[9]);
else txt.setText("Please choose a country.");
}
}

Mick Barry

Yes, you'll need to pass reference to the relevant objects or provide methods to perform required functionality.

Mick Barry

The same way ANY classes would interact.

alrav79

ASKER

ok, I now put the classes in their own appropriate files, and both of them compile perfectly. But when the applet loads, it acts as if the if statements arent there. No matter what i check, there is no response. I passed reference by making a WarApplet object "a" in the CheckBoxListener class, like this:

WarApplet a = new WarApplet();
...
...
..
if (a.england.isSelected())
..
you get the point

CEHJ

A more elegant way to do this would be to take a bit masking approach. You'll find if you create an array of checkboxes, this may help in connection with this way of doing things.

final static int FRANCE = 1 << 0;
final static int ENGLAND = 1 << 1;
...

final static int FRANCE_ENGLAND = ENGLAND | FRANCE;

Mick Barry

You need to pass a reference of WarApplet to you listener class, not create a new one.

alrav79

ASKER

explain how please with an example

Mick Barry

public CheckBoxListener(WarApplet applet)
{
a = applet;
}

Venci75

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SpideyMod

per recommendation

SpideyMod
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