Creating a basic paint program

Since we have learned so much about the QPainter class and how to use it to display graphics onscreen, I guess it's time for us to do something fun with which we can put our knowledge into practice.

In this recipe, we will learn how to make a basic paint program that allows us to draw lines on a canvas with different brush sizes and colors. We will also learn how to use the QImage class and mouse events in order to construct the paint program.

How to do it...

Let's start our fun project through the following steps:

1. Again, we start by creating a new Qt Widgets Application project and removing the tool bar and status bar. We will keep the menu bar this time.
2. After that, set up the menu...