Book Image

Cross-Platform Development with Qt 6 and Modern C++

By : Nibedit Dey
Book Image

Cross-Platform Development with Qt 6 and Modern C++

By: Nibedit Dey

Overview of this book

Qt is a cross-platform application development framework widely used for developing applications that can run on a wide range of hardware platforms with little to no change in the underlying codebase. If you have basic knowledge of C++ and want to build desktop or mobile applications with a modern graphical user interface (GUI), Qt is the right choice for you. Cross-Platform Development with Qt 6 and Modern C++ helps you understand why Qt is one of the favorite GUI frameworks adopted by industries worldwide, covering the essentials of programming GUI apps across a multitude of platforms using the standard C++17 and Qt 6 features. Starting with the fundamentals of the Qt framework, including the features offered by Qt Creator, this practical guide will show you how to create classic user interfaces using Qt Widgets and touch-friendly user interfaces using Qt Quick. As you advance, you'll explore the Qt Creator IDE for developing applications for multiple desktops as well as for embedded and mobile platforms. You will also learn advanced concepts about signals and slots. Finally, the book takes you through debugging and testing your app with Qt Creator IDE. By the end of this book, you'll be able to build cross-platform applications with a modern GUI along with the speed and power of native apps.
Table of Contents (17 chapters)
Section 1: The Basics
Section 2: Cross-Platform Development
Section 3: Advanced Programming, Debugging, and Deployment

Understanding events and the event loop

Qt is an event-based system, and all GUI applications are event-driven. In an event-driven application, there is usually a main loop that listens for events and then triggers a callback function when one of those events is detected. Events can be spontaneous or synthetic. Spontaneous events come from the outside environment. Synthetic events are custom events generated by the application. An event in Qt is a notification that represents something that has happened. Qt events are value types, derived from QEvent, which offers a type enumeration for each event. All events that arise inside a Qt application are encapsulated in objects that inherit from the QEvent class. All QObject derived classes can override the QObject::event() function in order to handle events targeted by their instances. Events can come from both inside and outside the application.

When an event occurs, Qt produces an event object by constructing an appropriate QEvent subclass...