Book Image

Cross-Platform Development with Qt 6 and Modern C++

By : Nibedit Dey
Book Image

Cross-Platform Development with Qt 6 and Modern C++

By: Nibedit Dey

Overview of this book

Qt is a cross-platform application development framework widely used for developing applications that can run on a wide range of hardware platforms with little to no change in the underlying codebase. If you have basic knowledge of C++ and want to build desktop or mobile applications with a modern graphical user interface (GUI), Qt is the right choice for you. Cross-Platform Development with Qt 6 and Modern C++ helps you understand why Qt is one of the favorite GUI frameworks adopted by industries worldwide, covering the essentials of programming GUI apps across a multitude of platforms using the standard C++17 and Qt 6 features. Starting with the fundamentals of the Qt framework, including the features offered by Qt Creator, this practical guide will show you how to create classic user interfaces using Qt Widgets and touch-friendly user interfaces using Qt Quick. As you advance, you'll explore the Qt Creator IDE for developing applications for multiple desktops as well as for embedded and mobile platforms. You will also learn advanced concepts about signals and slots. Finally, the book takes you through debugging and testing your app with Qt Creator IDE. By the end of this book, you'll be able to build cross-platform applications with a modern GUI along with the speed and power of native apps.
Table of Contents (17 chapters)
Section 1: The Basics
Section 2: Cross-Platform Development
Section 3: Advanced Programming, Debugging, and Deployment

Switching languages dynamically

So far, you have learned how to use the system language or a default language for your Qt application. In most applications, you can just detect the language in main() and load an appropriate .qm file. Sometimes, your application must be able to support changes to the user's language settings while still running. An application that is used by multiple people in shifts may need to switch languages without requiring a restart.

To achieve this in a Qt Widgets-based application, you can override QWidget::changeEvent(). Then, you have to check whether the event is of the QEvent::LanguageChange type. You can retranslate the user interface accordingly.

The following code snippet explains how to achieve dynamic translation in a Qt Widgets-based GUI:

void CustomWidget::changeEvent(QEvent *event)
    if (QEvent::LanguageChange == event->type())