Make a JCheckBox unable to be checked

Question

I'm a beginner in java and I have a gui in java that has two rows of 3 checkboxes ! I want to enable the second row according to the checkboxes that are check in the first ! For example if I check the first row first checkbox , then the sexond row first checkbox to be enabled !In other words I want the checkboxes in the second row to be unable to be checked unless a checkbox from the first row is checked ! I have tried almost every method from the oracle's documentation but nothing works ! Any idea will be helpful !

EDIT :

GetButton.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            if(!cEntertainment.isSelected() && !cEducation.isSelected() && !cFood.isSelected()){
                textArea.setText("Error ! Please select a Category and THEN a Type !");
                cDrink.setEnabled(false);
            }
        }


    });

Answer 1

You could add an ItemListener to the JCheckBox. Whenever you (un)select a JTextBox, this event will be triggered. Then, you can check which JTextBox was changed and it's new value, and then enable the JTextBox on the other row (with JCheckBox.setEnabled(true/false)).

See more info here: http://docs.oracle.com/javase/tutorial/uiswing/events/itemlistener.html

Answer 2

It sounds like what you want to do is to add a item listener on each checkbox in the first row, and have that listener enable or disable the corresponding checkbox in the second row.

JCheckBox[] checkPair(String top, String bottom) {
   final JCheckBox[] ret = { new JCheckBox(top), new JCheckBox(bottom) };
   ret[0].addItemListener(new ItemListener() {
      void itemStateChanged(ItemEvent e) {
         ret[1].setEnabled(ret[0].isSelected());
         ret[1].setSelected(ret[1].isSelected() && ret[0].isSelected());
      }
   });
   return ret;
}

Answer 3

As an alternative to any approach that uses listeners, you could use a "read-only" model for the JCheckBox:

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

public class ReadOnlyJCheckBoxDemo implements Runnable
{
  public static void main(String[] args)
  {
    SwingUtilities.invokeLater(new ReadOnlyJCheckBoxDemo());
  }

  public void run()
  {
    JCheckBox choice1 = new JCheckBox("Red");
    choice1.setModel(new ReadOnlyToggleButtonModel(true));
    choice1.setFocusable(false);

    JCheckBox choice2 = new JCheckBox("Green");
    choice2.setModel(new ReadOnlyToggleButtonModel(false));
    choice2.setFocusable(false);

    JPanel buttonPanel = new JPanel(new GridLayout(2,1));
    buttonPanel.add(choice1);
    buttonPanel.add(choice2);

    JFrame f = new JFrame();
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    f.add(buttonPanel);
    f.pack();
    f.setLocationRelativeTo(null);
    f.setVisible(true);
  }

  public class ReadOnlyToggleButtonModel extends ToggleButtonModel
  {
    public ReadOnlyToggleButtonModel()
    {
      super();
    }

    public ReadOnlyToggleButtonModel(boolean selected)
    {
      super();
      super.setSelected(selected);
    }

    @Override
    public void setSelected(boolean b)
    {
      // intentionally do nothing
    }
  }
}