Book Image

Mastering Qt 5 - Second Edition

By : Guillaume Lazar, Robin Penea
Book Image

Mastering Qt 5 - Second Edition

By: Guillaume Lazar, Robin Penea

Overview of this book

Qt 5.11 is an app development framework that provides a great user experience and develops full capability applications with Qt Widgets, QML, and even Qt 3D. Whether you're building GUI prototypes or fully-fledged cross-platform GUI applications with a native look and feel, Mastering Qt 5 is your fastest, easiest, and most powerful solution. This book addresses various challenges and teaches you to successfully develop cross-platform applications using the Qt framework, with the help of well-organized projects. Working through this book, you will gain a better understanding of the Qt framework, as well as the tools required to resolve serious issues, such as linking, debugging, and multithreading. You'll start off your journey by discovering the new Qt 5.11 features, soon followed by exploring different platforms and learning to tame them. In addition to this, you'll interact with a gamepad using Qt Gamepad. Each chapter is a logical step for you to complete in order to master Qt. By the end of this book, you'll have created an application that has been tested and is ready to be shipped.
Table of Contents (16 chapters)

CpuWidget using QCharts

Now that the SysInfoWidget base class is ready, let's implement its first child class: CpuWidget. We will now use the Qt Charts API to display a good-looking widget. The average CPU load will be displayed in a pie graph with a hole in the center, like a partly-eaten donut where the eaten part is the percentage of the CPU used. The first step is to add a new C++ class, named CpuWidget, and make it inherit SysInfoWidget:

#include "SysInfoWidget.h" 
class CpuWidget : public SysInfoWidget 
    explicit CpuWidget(QWidget* parent = 0); 

In the constructor, the only parameter needed is QWidget* parent. Since we provided default values for the startDelayMs and updateSeriesDelayMs variables in the SysInfoWidget class, we get the best possible behavior; there is no need to remember it when subclassing SysInfoWidget, but it is still...