Preface
Qt 5, the latest version of Qt, enables you to develop applications with complex user interfaces for multiple targets. It provides you with faster and smarter ways to create modern UIs and applications for multiple platforms. This book will teach you how to design and build graphical user interfaces that are functional, appealing, and user-friendly.
By the end of this book, you will have successfully learned about high-end GUI applications and will be capable of building many more powerful, cross-platform applications.
Who this book is for
This book will appeal to developers and programmers who would like to build GUI-based applications. Basic knowledge of C++ is necessary, and the basics of Qt would be helpful.
What this book covers
Chapter 1, Introduction to Qt, will give you a tour of Qt. In this book, you'll download the SDK, install Qt, and, most importantly, install Qt Creator, which is used as both the user interface designer and the IDE for writing and compiling C++ scripts.
Chapter 2, Qt Widgets and Style Sheets, will introduce you to the different types of widgets generally used in Qt to develop desktop applications. You will learn the first step to create your own application, which uses all kinds of widgets and customizations, using the powerful style sheet mechanism provided by Qt, which is very similar to CSS for web.
Chapter 3, Database Connection, will introduce you to the MariaDB database and teach you how to connect to it using Qt. You will first learn what is MariaDB database and how to call simple SQL commands to fetch and insert data into a MariaDB database. We will then create a simple but fully functional login page.
Chapter 4, Graphs and Charts, explores the Chart feature to allow users to easily render different types of graphs and charts, such as pie chart, bar chart, and line graph. We will make use of the knowledge learned from this chapter to create a dashboard page for an application, which displays all kinds of statistical summary of their company and business.
Chapter 5, Item Views and Dialogs, will teach you how to display a list of information by using three different item view widgets—a list widget, tree widget, and table widget. You will also learn how to prompt a message box to display error messages, warnings, and confirmation. You will then create an application that can load, scale, and crop images.
Chapter 6, Integrating Web Content, will empower you to use the Qt WebEngine module and make a simple web browser, which displays a web page. We will then go through what is sessions, cookies, and cache and subsequently how to manage them with Qt WebEngine. Finally, you will learn how to make your C++ code communicate with JavaScript content through the WebChannel mechanism.
Chapter 7, Map Viewer, will focus on creating a map display. This map will be used to display the location of places and people. You will learn how to implement the QtLocation module, understand the coordinate system, display location markers on the map, and so on.
Chapter 8, Graphics View, will provide a platform to manage and interact with a large number of custom-made graphical items and a view widget to visualize the items with support for zooming and rotation. You will learn how to make an organization's chart page that displays the structure of an organization and the relationships and relative ranks of its parts and positions/jobs.
Chapter 9, The Camera Module, will explore how to display camera images using Qt. Qt provides us with a multimedia module that enables us to easily take advantage of a platform's multimedia capabilities, such as connecting to the camera of the computer.
Chapter 10, Instant Messaging, will discuss the networking module and help us to make our own simple instant messaging program.
Chapter 11, Implementing a Graphics Editor, is divided into two sections, based on the two types of graphics in the rendering world–bitmap graphics and vector graphics. Both are quite different but essential to learning in order to understand 2D graphics rendering. You will learn how to draw graphics using Qt in this chapter.
Chapter 12, Cloud Storage, will teach you how to upload different types of files to the FTP server and display them in a list. The user will be able to download the file and open them with different types of viewers depending on its file format.
Chapter 13, Multimedia Viewers, will deal with creating a media player instead of using the default software on your computer. In this chapter, you will learn how to create an image viewer, a music player, and a video player.
Chapter 14, Qt Quick and QML, will introduce you to the basics of QML scripting, which is one of the most recent trends in the Qt world.
Chapter 15, Cross-Platform Development, will show you how to export applications to different platforms without re-writing the code from scratch. You will learn some of the essential settings and tips to look out for when porting applications to different platforms. Besides PC platforms, you will also learn how to export applications to mobile platforms.
Chapter 16, Testing and Debugging, will teach you the essentials of how to use various techniques to test and debug your Qt application.
To get the most out of this book
In order to successfully execute all the codes and instructions in this book, you would need the following:
- A basic PC/Laptop
- A working internet connection
- Qt 5.10
- MariaDB 10.2 (or MySQL Connector)
- Filezilla Server 0.9
We will deal with the installation processes and details as we go through each chapter.
Download the example code files
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Download the color images
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Conventions used
There are a number of text conventions used throughout this book.
CodeInText: Indicates code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. Here is an example: "We call the test() function at the MainWindow constructor."
A block of code is set as follows:
void MainWindow::test()
{
int amount = 100;
amount -= 10;
qDebug() << "You have obtained" << amount << "apples!";
} When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
test();
} Any command-line input or output is written as follows:
********* Start testing of MainWindow *********
Config: Using QtTest library 5.9.1, Qt 5.9.1 (i386-little_endian-ilp32 shared (dynamic) debug build; by GCC 5.3.0)
PASS : MainWindow::initTestCase()
PASS : MainWindow::_q_showIfNotHidden()
PASS : MainWindow::testString()
PASS : MainWindow::testGui()
PASS : MainWindow::cleanupTestCase()
Totals: 5 passed, 0 failed, 0 skipped, 0 blacklisted, 880ms
********* Finished testing of MainWindow *********Bold: Indicates a new term, an important word, or words that you see onscreen. For example, words in menus or dialog boxes appear in the text like this. Here is an example: "The third option is Toggle Bookmark, which lets you set a bookmark for your own reference."
Note
Warnings or important notes appear like this.
Note
Tips and tricks appear like this.
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