Question

I write a program in java and used a several components that takes action(actionListener) in my program.
I want to know when any action happened by this component. For example when I clicked the button or a menu item , call a method.

public class ButtonFrame extends JFrame
{
   private JButton plainJButton; // button with just text
   private JButton fancyJButton; // button with icons

   public ButtonFrame()
   {
      super( "Testing Buttons" );
      setLayout( new FlowLayout() ); // set frame layout

      plainJButton = new JButton( "Plain Button" ); 

      add( plainJButton ); 


      fancyJButton = new JButton( "Fancy Button"); 

      add( fancyJButton );

      // create new ButtonHandler for button event handling
      ButtonHandler handler = new ButtonHandler();
      fancyJButton.addActionListener( handler );
      plainJButton.addActionListener( handler );
   } 


   private class ButtonHandler implements ActionListener
   {

      public void actionPerformed( ActionEvent event )
      {
         JOptionPane.showMessageDialog( ButtonFrame.this, String.format(
            "You pressed: %s", event.getActionCommand() ) );
      } 
   } 
}

Answer 1

Use event.getSource() to differentiate between registered components.

Example –

if(plainJButton == event.getSource()){
    // do stuff (e.g. show message dialog, invoke method, and etc.)
}
else if(fancyJButton == event.getSource()){
    // do stuff (e.g. show message dialog, invoke method, and etc.)
}
else{
    // ut-oh..time to panic!
}