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)

Loading a database on mobile devices

Before continuing the UI implementation, we have to handle database deployment on mobile devices (spoiler alert: this will not be fun!).

We have to jump back to DatabaseManager.cpp in the gallery-core project:

DatabaseManager& DatabaseManager::instance() 
{ 
    return singleton; 
} 
 
DatabaseManager::DatabaseManager(const QString& path) : 
    mDatabase(new QSqlDatabase(QSqlDatabase::addDatabase("QSQLITE"))), 
    albumDao(*mDatabase), 
    pictureDao(*mDatabase) 
{ 
    mDatabase->setDatabaseName(path); 
    ... 
} 

Although, on desktop devices, the SQLite3 database is created with the instruction mDatabase->setDatabaseName(), on mobile devices, it does not work at all. This is due to the fact that the filesystem is very specific on each mobile platform (Android and iOS). An application only has access to a narrow...