JToggleButton

      A toggle button is just like a push button, but it is different because it has two states: pushed and released. That is, when we press a toggle button, it stays pressed rather than popping back up as a rectangular push button does. When we press the toggle button a second time, it releases (pops up).

      JToggleButton implements AbstractButton. JToggleButton is a superclass for two other Swing components that also represent two-state control: JCheckBox and JRadioButton.

      One of the widely used constructor for JToggleButton is as follows:

JToggleButton(String str)

Here, a toggle button is created that contains the string str.

      By default the button is in off position. JToggleButton uses a model defined by a nested class called JToggleButton.ToggleButtonModel.

      Like JButton, JToggleButton generates an action event each time it is pressed.

      Unlike JButton, JToggleButton also generates an item event. This event is used by those components that support the concept of selection.

      The easiest way to determine a toggle button’s state is by calling the isSelected() method on the button that generated the event.

boolean isSelected()

It returns true if the button is selected otherwise false.

      Example:

import java.awt.*;

import javax.swing.*;

import java.awt.event.*;

public class MyToggleButton extends JApplet

{

  JLabel l1;

  JToggleButton jb;

  public void init()

  {

   try

   {

    SwingUtilities.invokeAndWait(new Runnable() {

      public void run()

      {

          makeGUI();

      }

    });

  } catch(Exception e){

           System.out.println("Sorry some error occured "+e);

        }

 }

 private void makeGUI()

 {

   setLayout(new FlowLayout());

   l1=new JLabel("Off");

   jb=new JToggleButton("On/Off");

   jb.addActionListener(new ActionListener(){

     public void actionPerformed(ActionEvent ae){  

      if(jb.isSelected())

            l1.setText("On");

      else

            l1.setText("Off");       

    }

   });

   add(jb);

   add(l1);

 }

}

Output: