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)

Signals and slots

In Qt, this action-response scheme is handled by signals and slots. This section will include a few definitions, and then we shall jump into an example for further explanation.

A signal is a message that is passed to communicate that the state of an object has changed. This signal may carry information about the change that has occurred. For instance, when a window has been resized, the signal will usually carry the coordinates of the new state (or size) of the window. Sometimes, a signal may carry no extra information, such as that of a button click.

A slot is a specific function of an object that is called whenever a certain signal has been emitted. Since slots are functions, they will embody lines of code that perform an action, such as closing a window, disabling a button, and sending an email, to mention but a few.

Signals and slots have to be connected...