Book Image

Mastering Qt 5

By : Guillaume Lazar, Robin Penea
Book Image

Mastering Qt 5

By: Guillaume Lazar, Robin Penea

Overview of this book

Qt 5.7 is an application development framework that provides a great user experience and develops full-capability applications with Qt Widgets, QML, and even Qt 3D. This book will address challenges in successfully developing cross-platform applications with the Qt framework. Cross-platform development needs a well-organized project. Using this book, you will have a better understanding of the Qt framework and the tools to resolve serious issues such as linking, debugging, and multithreading. Your journey will start with the new Qt 5 features. Then you will explore different platforms and learn to tame them. Every chapter along the way is a logical step that you must take to master Qt. The journey will end in an application that has been tested and is ready to be shipped.
Table of Contents (20 chapters)
Mastering Qt 5
Credits
About the Authors
About the Reviewer
www.PacktPub.com
Preface

Protecting your code with a smart pointer


The code we just described is fully functional, but, it can be strengthened, specifically with the function, AlbumDao::albums(). In this function, we iterate through the database rows and create a new Album to fill a list. We can zoom in on this specific code section:

QVector<Album*> list; 
while(query.next()) { 
    Album* album = new Album(); 
    album->setId(query.value("id").toInt()); 
    album->setName(query.value("name").toString()); 
    list.append(album); 
} 
return list; 

Let's say that the name column has been renamed to title. If you forget to update query.value("name"), you might run into trouble. The Qt framework does not rely on exceptions, but this cannot be said for every API available in the wild. An exception here would cause a memory leak: the Album* album function has been allocated on the heap but not released. To handle this, you would have to surround the risky code with a try catch statement and deallocate the...