Java Swing Tutorial - Java Swing JCheckBox

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A JCheckBox has two states: selected and unselected.

A group of JCheckBoxes is used when we need the user to make multiple choices.

We can use a combination of an Action object, a string label, an icon, and a boolean flag to indicate if it is selected by default to create JCheckbox.

Create JCheckBox with no label and no image

JCheckBox cb1  = new JCheckBox(); 

Create JCheckBox with text as "My Choice"

JCheckBox cb2  = new JCheckBox("My Choice"); 

Create JCheckBox with text as "My Choice" and selected by default

JCheckBox cb3  = new JCheckBox("My Choice", true);

To select/unselect a JCheckBox, to call the setSelected() methods.

To check if it is selected, use their isSelected() methods.

The following code shows how to use these methods:

tb3.setSelected(true);      // Select tb3
boolean b1  = tb3.isSelected(); 
// will store true in b1 
tb3.setSelected(false);    // Unselect tb3
boolean b2  = tb3.isSelected(); // will store false in b2

ActionListener

Listening to JCheckBox Events with an ActionListener

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
//from w w  w.  j  a  v a  2 s  . co m
import javax.swing.AbstractButton;
import javax.swing.JCheckBox;
import javax.swing.JFrame;

public class Main {
  public static void main(String args[]) {
    JFrame frame = new JFrame("Iconizing CheckBox");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    JCheckBox aCheckBox4 = new JCheckBox("Stuffed Crust");

    ActionListener actionListener = new ActionListener() {
      public void actionPerformed(ActionEvent actionEvent) {
        AbstractButton abstractButton = (AbstractButton) actionEvent.getSource();
        boolean selected = abstractButton.getModel().isSelected();
        System.out.println(selected);
        // abstractButton.setText(newLabel);
      }
    };
    aCheckBox4.addActionListener(actionListener);
    frame.add(aCheckBox4);
    frame.setSize(300, 200);
    frame.setVisible(true);
  }
}

ItemListener

Listening to JCheckBox Events with an ItemListener

import java.awt.Color;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
/* w w  w .  j a v  a 2  s . com*/
import javax.swing.AbstractButton;
import javax.swing.JCheckBox;
import javax.swing.JFrame;

public class JCheckBoxItemListener {
  public static void main(String args[]) {
    JFrame frame = new JFrame("Iconizing CheckBox");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    JCheckBox aCheckBox4 = new JCheckBox("Stuffed Crust");

    ItemListener itemListener = new ItemListener() {
      public void itemStateChanged(ItemEvent itemEvent) {
        AbstractButton abstractButton = (AbstractButton)itemEvent.getSource();
        Color foreground = abstractButton.getForeground();
        Color background = abstractButton.getBackground();
        int state = itemEvent.getStateChange();
        if (state == ItemEvent.SELECTED) {
          abstractButton.setForeground(background);
          abstractButton.setBackground(foreground);
        }
      }
    };
    aCheckBox4.addItemListener(itemListener);
    frame.add(aCheckBox4);
    frame.setSize(300, 200);
    frame.setVisible(true);
  }
}

ChangeListener

Listening to JCheckBox Events with a ChangeListener: listen to armed, pressed, selected, or released state

import javax.swing.AbstractButton;
import javax.swing.ButtonModel;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
/*  ww  w . j av  a 2  s.  co m*/
public class Main {
  public static void main(String args[]) {
    JFrame frame = new JFrame("Iconizing CheckBox");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    JCheckBox aCheckBox4 = new JCheckBox("Stuffed Crust");

    // Define ChangeListener
    ChangeListener changeListener = new ChangeListener() {
      public void stateChanged(ChangeEvent changeEvent) {
        AbstractButton abstractButton =
          (AbstractButton)changeEvent.getSource();
        ButtonModel buttonModel = abstractButton.getModel();
        boolean armed = buttonModel.isArmed();
        boolean pressed = buttonModel.isPressed();
        boolean selected = buttonModel.isSelected();
        System.out.println("Changed: " + armed + "/" + pressed + "/" +
          selected);
      }
    };

    aCheckBox4.addChangeListener(changeListener);
    frame.add(aCheckBox4);
    frame.setSize(300, 200);
    frame.setVisible(true);
  }
}

The code above generates the following result.

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