Chapter 14, Problem 4SA

Program Plan Intro

Applet:

• A Java applet is a small program usually coded in Java language and produces the bytecode. It is embed into an HTML document.
  • The coded program (applet) is moved over the web.
  • Then the applet is executed to view the web page in the Java compatible web browser.
    • The web browser uses JVM (Java Virtual Machine) to execute the java applet code.
• The java applet supported for various platforms such as Microsoft Windows, UNIX and Linux etc.
• The Java applet is simple and mostly supported by all web browsers.
• The tag <APPLET> is used to embed a java applet program into an HTML document.

Graphical user Interface (GUI):

• A GUI denotes a graphical window or a system of graphical windows.
• It is presented by an application for user interaction purpose.
• It accepts input from the keyboard.
• It also accepts input from mouse or a touch screen.
• The GUI components include “Buttons”, “Labels”, “TextFields”, “CheckBoxes” and “RadioButtons”.
• The programs that operate in a GUI based environment must be event-driven.
• An “event” denotes an action that would take place within a program.
• The creation of event listeners is part of GUI application.
• An event listener denotes a method that executes automatically when a specific event occurs.
• An event listener may respond to an event that occurs within an operation.