Book Image

Getting Started with Qt 5

By : Benjamin Baka
Book Image

Getting Started with Qt 5

By: Benjamin Baka

Overview of this book

Qt is a cross-platform application framework and widget toolkit that is used to create GUI applications that can run on different hardware and operating systems. The main aim of this book is to introduce Qt to the reader. Through the use of simple examples, we will walk you through building blocks without focusing too much on theory. Qt is a popular tool that can be used for building a variety of applications, such as web browsers, media players such as VLC, and Adobe Photoshop. Following Qt installation and setup, the book dives straight into helping you create your first application. You will be introduced to Widgets, Qt's interface building block, and the many varieties that are available for creating GUIs. Next, Qt's core concept of signals and slots are well illustrated with sufficient examples. The book further teaches you how to create custom widgets, signals and slots, and how to communicate useful information via dialog boxes. To cap everything off, you will be taken through writing applications that can connect to databases in order to persist data. By the end of the book, you should be well equipped to start creating your own Qt applications and confident enough to pick up more advanced Qt techniques and materials to hone your skills.
Table of Contents (8 chapters)

Creating a custom window

To create a window(ed) application, we usually call the show() method on an instance of QWidget and that makes that widget, to be contained in a window of its own, along with its child widgets displayed in it.

A recap of such a simple application is as follows:

#include <QApplication>
#include <QMainWindow>
#include <QLabel>
int main(int argc, char *argv[])
QApplication a(argc, argv);
QMainWindow mainWindow;;
return a.exec();

mainWindow here is an instance of QMainWindow, which is derived from QWidget. As such, by calling the show() method, a window will appear. If you were to replace QMainWindow with QLabel, this will still work.

But this style of writing applications is not the best. Instead, from this point onward, we shall define our own custom widget, in which we shall define child widgets and make connections...