implements ActionListener and action class level variable : ActionListener « Swing Event « Java Tutorial

1. Java Tutorial
2. Swing Event
3. ActionListener

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JTextField;

public class MainClass extends JFrame {
  JTextField field = new JTextField();

  public static void main(String[] args) {
    MainClass st = new MainClass();
  }

  public SwingTest() {
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    JButton button = new JButton("Press me");
    button.addActionListener(new ButtonListener());
    this.getContentPane().setLayout(new BorderLayout());
    this.getContentPane().add(button, BorderLayout.SOUTH);
    this.getContentPane().add(field, BorderLayout.NORTH);
    this.pack();
    this.setVisible(true);
  }

  class ButtonListener implements ActionListener {
    boolean toggle = true;

    public void actionPerformed(ActionEvent e) {
      if (toggle)
        field.setText("Simple");
      else
        field.setText("Sample");
      toggle = !toggle;
    }
  }
}

15.5.ActionListener
	15.5.1.	implements ActionListener and action class level variable
	15.5.2.	Handling an action listener
	15.5.3.	Check the event source in actionPerformed method
	15.5.4.	Use an Inner Class to handle the event
	15.5.5.	Use one inner class to handle events from two buttons
	15.5.6.	Get event source from ActionEvent
	15.5.7.	Add action listener to JTextField
	15.5.8.	ComboBox with ActionListener
	15.5.9.	ActionEvent.getActionCommand()
	15.5.10.	Using an inner ActionListener class.