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)

Generating random numbers

Generating real random numbers is quite a difficult task for a computer. Commonly, we only use a pseudo-random number generation (PRNG). The Qt framework provides the function qrand(), a thread-safe version of std::rand(). This function returns an integer between 0 and RAND_MAX (defined in <cstdlib>). The following code shows two pseudo-random numbers:

qDebug() << "first number is" << qrand() % 10;
qDebug() << "second number is" << qrand() % 10;

We are using a modulo operator to get a value between 0 and 9. Try to run your application several times. The numbers are always the same; in our case, the numbers are 3 and 7. That is because each time we call qrand(), we retrieve the next number of the pseudo-random sequence—but the sequence is always the same! Fortunately, we can use qsrand() to initialize...