Book Image

Application Development with Qt Creator - Third Edition

By : Lee Zhi Eng, Ray Rischpater
Book Image

Application Development with Qt Creator - Third Edition

By: Lee Zhi Eng, Ray Rischpater

Overview of this book

Qt is a powerful development framework that serves as a complete toolset for building cross-platform applications, helping you reduce development time and improve productivity. Completely revised and updated to cover C++17 and the latest developments in Qt 5.12, this comprehensive guide is the third edition of Application Development with Qt Creator. You'll start by designing a user interface using Qt Designer and learn how to instantiate custom messages, forms, and dialogues. You'll then understand Qt's support for multithreading, a key tool for making applications responsive, and the use of Qt's Model-View-Controller (MVC) to display data and content. As you advance, you'll learn to draw images on screen using Graphics View Framework and create custom widgets that interoperate with Qt Widgets. This Qt programming book takes you through Qt Creator's latest features, such as Qt Quick Controls 2, enhanced CMake support, a new graphical editor for SCXML, and a model editor. You'll even work with multimedia and sensors using Qt Quick, and finally develop applications for mobile, IoT, and embedded devices using Qt Creator. By the end of this Qt book, you'll be able to create your own cross-platform applications from scratch using Qt Creator and the C++ programming language.
Table of Contents (19 chapters)
1
Section 1: The Basics
7
Section 2: Advanced Features
12
Section 3: Practical Matters

Accessing sensors with C++

So far, we have learned how we can access the sensors' data through QML scripting. However, the sensors can also be accessed through Qt's various C++ classes. We will walk through some examples of this and demonstrate how we can achieve that.

First, create an empty Qt project (you can continue from the previous example if you wish, though). Instead of writing the code in the .qml file, we will open up main.cpp instead. After that, we will include some headers so that we can access these classes. Remember to add the sensors module to your project file (.pro) if you are creating a new Qt project:

#include <QDebug>
#include <QTimer>

#include <QAccelerometer>
#include <QAmbientLightSensor>
#include <QProximitySensor>

#include <QAccelerometerReading>
#include <QAmbientLightReading>
#include <QProximityReading...