The Qt Framework


If you need a robust and versatile framework to streamline your application development process, there is no better tool than the Qt Framework. With it you can unlock the potential to create applications and graphical user interfaces that seamlessly run across various operating systems. With Qt’s Write Once, Run Anywhere (WORA) principle, you can save both time and effort. Read on as we explore the wonders of Qt and discover how it can revolutionize your development projects.

Table of Contents

The history of the Qt framework

In the early 1990s, Eirik Chambe-Eng and Haavard Nord created the foundation for Qt as part of their university project. They developed a GUI library that worked across Windows and Linux and later established Trolltech to further develop and commercialize Qt. Qt was unique with its dual licensing model, offering both open-source and commercial versions, which attracted a broad range of users.

Qt’s popularity grew, especially after 1996, when German Mathias Ettrich used it to create KDE, a Linux desktop environment. This project helped to highlight Qt’s strengths and opened up new application possibilities.

After Trolltech’s success, the company was taken over by Nokia, which planned to integrate Qt into their mobile devices. This period was marked by uncertainty for Qt, as Nokia had only acquired Trolltech to use the technology for their phones, and therefore had no interest in keeping it open-source. Fortunately, in 2012, the development of Qt resumed when Nokia sold the framework to Digia. Under the new name The Qt Company, Qt has seen a resurgence and excels, especially in automotive and embedded systems.

Today, Qt stands as a leading framework in software development, continuing to evolve and stay relevant in the digital age.

Qt Logos

Qt's Unique Features

Qt stands out in the software development world for its simplicity and versatility. Its cross-platform nature allows developers to write code once and apply it on multiple platforms, saving time and reducing errors. This is an objectively unmatched feature by other technologies, making Qt a preferred choice for a wide spectrum of applications, from desktop and embedded systems to, to a lesser extent, mobile devices.

Qt’s simplicity is particularly evident in comparison to other technologies like Windows-based systems, where Qt systems generally require fewer lines of code. This makes it not only easier to use but also more efficient and reliable.

The high praise Qt receives from engineers for being “less bad” than other systems reflects its robustness and efficiency in practice. Qt’s design philosophy focuses on making the development process as smooth and hassle-free as possible, which is reflected in its continued popularity and use in many different types of software projects.

Qt Creator and Collaboration

Qt Creator stands as a key player in the Qt framework, functioning as an integrated development environment (IDE) specifically designed to facilitate the development of Qt applications. Its existence stems from the need for a cross-platform IDE that efficiently supports C++ development, as opposed to the more Java-based alternatives on the market.

Besides being an advanced text editor, Qt Creator offers an overview of projects, integrated launch functions, and a powerful debugger. This makes it an ideal tool for developers working with Qt software, as it offers a more natural and intuitive approach to software development, especially within open-source environments.

Compared to other major development tools like Microsoft’s Visual Studio, Qt Creator stands out for being lighter and less resource-intensive. This means that Qt Creator does not dominate workflows in the same way as some of the heavier alternatives, giving developers greater freedom and flexibility in their workflows.

Ultimately, Qt Creator significantly contributes to the strength of the Qt framework by offering a user-friendly and efficient tool that streamlines the development process and supports collaboration among developers.

Cross-platform Development

One of the most significant features of Qt is its ability to support development across different platforms, including Windows, Linux, and in some cases, mobile devices. This capability is fundamental to Qt’s design and appeals to developers who want to create applications that can function seamlessly on different operating systems.

Qt achieves this platform independence by abstracting the underlying operating system. This means that developers can write code once in Qt and trust that this code will work on multiple platforms. Qt’s internal translation of platform-specific details is key to this functionality.

An example of Qt’s ability to adapt to different platforms is its application in the automotive sector. Here, Qt is adapted to work with car-related hardware and software, while ignoring elements relevant to desktop environments, such as printer management. Similarly, when Qt is used for desktop applications, it focuses on desktop-specific features and omits elements relevant to automotive systems.

This aspect of Qt is especially valued in situations where quick and seamless cross-platform development is necessary. However, it should be noted that Qt’s application to mobile applications can be limited compared to its capabilities within desktop and embedded systems.

Add-ons and Specialized Extensions

The Qt framework is enriched through a range of add-ons and specialized extensions that expand its functionality and usability in specific application areas. These add-ons enable developers to customize and enhance their applications by integrating specific functionality that suits their unique needs.

An example is “Boot to Qt,” which allows the use of Android tablets as dedicated Qt devices, effectively eliminating the need to work with separate drivers. This type of add-on demonstrates how Qt can be adapted to work with specific hardware, enabling faster and more efficient development of dedicated devices.

Another important extension is “Automotive Qt,” which is tailored for the development of embedded systems in the automotive industry. This specialization of Qt highlights its flexibility and ability to be tailored to specific industrial needs. Additionally, “Qt for MCU” (Microcontroller Units) demonstrates Qt’s capabilities in very small, embedded systems, opening up possibilities in miniaturized hardware.

These add-ons and extensions illustrate Qt’s versatility and its ability to support a wide range of application areas. They are generally designed to be “special purpose” extensions, meaning they are available for those who need them, without overwhelming those who do not.

Different Types of User Interfaces in Qt

Qt offers a flexible and dynamic foundation for developing various types of user interfaces. Its design philosophy centers on giving developers the freedom to realize almost any user interface idea. Qt does not limit developers to specific user interface designs; instead, it provides a wealth of technological possibilities, allowing the creation of a wide range of user interfaces.

One of Qt’s strengths is its versatility, which makes it suitable for both desktop and embedded applications. Its flexibility allows developers to tailor user interfaces to specific needs and environments. Although some user interface tasks may be more challenging to implement in Qt, it is generally possible to use Qt to design all types of user interfaces.

This approach contrasts with other technologies, which often grew out of specific system needs and therefore may be more limited in their application areas. Qt’s open and accessible nature makes it an ideal choice for projects that require creative freedom and technical versatility to realize unique user experiences.

Database Management in Qt

Database management is an integral part of many modern applications, and Qt makes it easy for developers to integrate this functionality. Within Qt’s ecosystem, there is a sub-framework dedicated to interacting with databases, which is a core component of Qt Core. This enables developers to create and manage SQL connections and transactions directly within Qt applications.

While direct database interactions within the application itself are becoming less common, as many databases now primarily reside on servers, Qt still supports this functionality for scenarios where it is necessary. Examples of use include creating small local databases for caching or temporary data storage.

This functionality again proves Qt’s versatility. Although the need for direct database access has declined with the shift to cloud-based solutions, the ability to interact with databases remains an important part of many applications’ infrastructure, and Qt ensures that developers still have this option available.

Git repositories in Qt

Conclusion: Qt's Place in the Future of Software Development

Qt has proven to be a versatile and powerful tool in the world of software development. From its original development as a solution for cross-platform GUI design, to its current status as a preferred tool for a wide range of applications, Qt has proven its durability and relevance.

With its ability to support development across different platforms, from desktop to embedded systems, and its ongoing development and adaptation to today’s technological needs, Qt stands as a vital resource for software developers.

Bo’s insight highlights Qt’s versatility and strength, not only as a GUI tool but also as a comprehensive framework that supports various aspects of software development, including network communication, database management, and user interface design.