Java Programming Tutorial - 83 - FlowLayout

import java.awt.FlowLayout;
import java.awt.Container;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.JFrame;
import javax.swing.JButton;

class MyLayout extends JFrame {
   private JButton leftButton, centerButton, rightButton;
   private FlowLayout layout;
   private Container container;

   public static void main(String args[ ]) {
      MyLayout gui = new MyLayout();
      gui.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      gui.setSize(400, 150);
      gui.setVisible(true);
   }

   MyLayout() {
      super("imba layout program");
      layout = new FlowLayout();
      setLayout(layout);
      container = getContentPane();

      leftButton = new JButton("left");
      add(leftButton);
      centerButton = new JButton("center");
      add(centerButton);
      rightButton = new JButton("right");
      add(rightButton);

      HandlerClass handler = new HandlerClass();
      leftButton.addActionListener(handler);
      centerButton.addActionListener(handler);
      rightButton.addActionListener(handler);
   }

   private class HandlerClass implements ActionListener {
      public void actionPerformed(ActionEvent event) {
         if(event.getSource() == leftButton) {
            layout.setAlignment(FlowLayout.LEFT);
            layout.layoutContainer(container);
         }
         else if(event.getSource() == centerButton) {
            layout.setAlignment(FlowLayout.CENTER);
            layout.layoutContainer(container);
         }
         else if(event.getSource() == rightButton) {
            layout.setAlignment(FlowLayout.RIGHT);
            layout.layoutContainer(container);
         }
      }
   }
}