Chapter 15, Problem 5SA

Explanation of Solution

Event:

When a GUI (Graphical User Interface) program that are created gets responded to the action performed by the user it is called as event.

Example:

Consider a program that calculates the sum of two numbers, the user can enter two numbers in the “GUI” designed.

• The user can enter the number that needs to be added.
• The sum will be calculated only when the user click on the calculate button.
• The number that is entered can be modified whenever required until the calculate button is pressed.
• The event is triggered by the user such that the sum of numbers gets calculated.

Event handler:

An event handler is a module is implemented in python program executes automatically when a particular event has occurred.

• If user need a program to execute an operation at that time a particular event occurs, user must create an event handler that reply at that time of event takes place...