Swing Events can be described as a particular point of an instance or behavior of that instance.For instance, clicking on a Button, entering characters on the keyboard. Here Swing Events are divided into two types such as Foreground Events and Background Events. The functionality of Event Handling is what is the further step if an action performed. Java foundation introduced "Delegation Event Model"i.e describes how to generate and control the events. The key elements of the Delegation Event Model are as source and listeners. Source is an instance and supplies data about to happen event to the event handler. The listener is also an instance and it gives the return alert in the event after the event has been received. Before this process listener should have registered on source for the purpose of alert notifications. Delegation event model overcomes the problems of hierarchical models. Before constructing the listener class, a developer should have the listener interface which consists of callback methods.Callback methods should be implemented by listener class.

Below is the source code to show how the event will perform in the application. AEvent.java [java]package swing; import java.awt.*; import java.awt.event.*; class AEvent extends Frame implements ActionListener{ TextField tf; AEvent(){ tf=new TextField(); //creating textfield tf.setBounds(60,50,170,20); //creating bounds to the frame Button b=new Button("click me"); //if user click alerts will be passed b.setBounds(100,120,80,30); //creating bounds to the button box b.addActionListener(this); //after clicking on button it will be implemented add(b);add(tf); setSize(300,300); //creating size setLayout(null); setVisible(true); //it should always be as true setBackground(Color.red); //it depends on user requirements } public void actionPerformed(ActionEvent e){ tf.setText("SPlessons"); } public static void main(String args[]){ //here writing main method new AEvent(); } } [/java] Create a class that should extend from Frame and should implement ActionListener. Create constructor that should be same as class name. [java]class AEvent extends Frame implements ActionListener{ TextField tf; AEvent()[/java] Create text field, button and add ActionListener to this button. [java]tf=new TextField(); Button b=new Button("click me"); b.addActionListener(this); [/java] Action should perform on the textfield then it displays output as SPlessons. [java]public void actionPerformed(ActionEvent e){ tf.setText("SPlessons"); } [/java] Output: Output will be as follows. When  click on the click button,"Welcome to SPlessons" will be displayed in the text field.

Swing event classes play a major role in Swing applications and indicates the event. While developing an application based on the Swing technology developer can use more Swing classes depends on the requirement because Swing consists of more classes so it is a little bit hard to use all the classes in an application. Splessons will teach about commonly used classes. EventObject class is the base class and it can derive the exact behavior and state of the instance (object). It's available in the Java. util package.

Protected Object Source is the field of Java. util. EventObject, and on which only event will be happening initially. This class consists of methods also and these methods will be inherited from the Java. util. object.

• Swing Events - Listener interface should be registered with listener class.
• Swing Events - Event source, Event listeners, Event object are the participants of the Delegation Event Model.
• Swing Events - java.io.Serializable interface needs to be implemented by the class.
• Swing Events - int getID() is a method of AWTEvent i.e indicates the type of the event.