Chapter 15, Problem 7SA

Program Plan Intro

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.

Event:

• An “event” denotes an action that would take place within a program
• It can be an action that would occur as a result of user operations such as a key pressing or a mouse click.
• The events occurred are been processed using event handlers.
• An event listener may respond to an event that occurs within an operation.
• The actions corresponds to an event includes:
  • Mouse clicks or moves
  • Key pressing on keyboard
  • Disk I/O
  • Network activity
  • Interrupt