Qt vs. Flutter: Choosing the Right Framework

Qt vs. Flutter: Which Framework is Right for Your Embedded Project?

By David Poole and Stephanie Van Ness

In the realm of software development, choosing the appropriate framework is paramount to project success. When considering cross-platform application development, two prominent options are Qt and Flutter. Qt, established pre-1995, boasts a robust toolkit built on C++, providing versatility beyond graphical interfaces and catering to complex project requirements. In contrast, Flutter, introduced by Google in 2017, has garnered attention for its rapid development capabilities and cost-effectiveness, making it particularly appealing to budget-conscious developers.

This comparison between the established Qt and the emerging Flutter prompts the question: which framework aligns best with the needs of your next project?

Understanding Qt

Qt is a versatile software development framework renowned for its cross-platform capabilities. Utilizing C++ at its core, Qt enables developers to achieve native-level performance and efficiency across desktop, embedded systems and mobile devices using a unified codebase. In fact, the utilization of C++ in Qt offers unparalleled performance and control, crucial for high-performance applications. 

Qt’s extensive library ecosystem covers essential functionalities, such as networking, database access and multimedia, empowering developers with a robust toolkit for streamlined development processes and enhanced application functionality. Developers benefit not only from a rich assortment of libraries but also robust community support, which together helps accelerate development timelines and bolster application capabilities. 

Qt’s licensing options range from open-source licenses like LGPL to commercial licenses tailored for businesses, each with their own set of benefits and considerations. Developers must assess licensing requirements, budget constraints and support needs to make an informed decision aligning with project goals.

Exploring Flutter

Flutter's design philosophy revolves around empowering developers to create high-performance and visually stunning user interfaces (UIs) across multiple platforms using a single codebase. This approach not only streamlines development efforts but also ensures consistency and uniformity in UI design and functionality across various devices and operating systems. 

A standout feature of Flutter is its hot reload capability, which enables developers to make changes to the code and see the results instantaneously without the need for lengthy recompilation or app restarts. This rapid iteration cycle means developers can fine-tune UI elements, test different layouts, and implement features with unprecedented speed and efficiency. 

Dart serves as the foundational programming language for Flutter, offering developers a modern and efficient toolset for building cross-platform applications. Its syntax is clean, intuitive, and easy to learn, making it accessible to developers with varying levels of experience. Dart's syntax draws inspiration from several programming languages, incorporating familiar concepts such as classes, interfaces and asynchronous programming that are essential for developing robust and scalable applications. 

Here's a brief overview of Dart's syntax and capabilities, along with code snippets to illustrate key features:

Syntax and Learning Curve

Dart's syntax is designed to be concise and expressive, reducing boilerplate code and improving readability. For instance, defining a simple class in Dart looks like this:

class Person {
 String name;
 int age;
 Person(this.name, this.age);
 void greet() {
   print('Hello, $name!');
 }
}
void main() {
 var person = Person('John Doe', 30);
 person.greet();
}

In this example, we define a Person class with properties name and age, a constructor shorthand using this.name and this.age, and a method greet() to print a greeting message.

Community and Support

Dart benefits from a growing community of developers and a wealth of resources, including official documentation, tutorials, and libraries. The Dart ecosystem provides essential packages for tasks – such as HTTP requests, JSON parsing, state management, and more – enhancing productivity and accelerating development cycles.

In the code snippet below, we demonstrate fetching user data from a REST API using the http package, showcasing Dart's support for asynchronous operations and network requests.

import 'package:http/http.dart' as http;
Future<void> fetchUserData() async {
 var response = await http.get(Uri.parse('https://jsonplaceholder.typicode.com/users/1'));
 if (response.statusCode == 200) {
   print('User data: ${response.body}');
 } else {
   print('Failed to fetch user data.');
 }
}
void main() {
 fetchUserData();
}

Leveraging Dart's accessible syntax, manageable learning curve, and strong community support, developers can create high-performance, visually appealing, and feature-rich applications with ease. This approach not only eliminates the need for purchasing separate licenses for each platform but also streamlines development efforts and reduces ongoing maintenance costs. 

Additionally, Flutter's open-source nature provides access to extensive resources beyond just a vibrant community, such as thorough documentation and diverse third-party packages and tools, which contributes to Flutter’s position as a budget-friendly development ecosystem.

How to Choose Between Qt and Flutter?

When choosing a framework, it's crucial to consider the nuances of language and performance: C++ offers native performance advantages and fine-grained control over hardware resources, making it suited for high-performance applications that require access to low-level functionalities. Dart, with its modern syntax and ease of learning, makes Flutter accessible to a broader range of developers. So while C++ excels in performance-critical scenarios, Dart's simplicity and ease of use can lead to faster development cycles and reduced time-to-market for applications.

The ecosystem and community support for both frameworks also play a significant role. Qt, with its established libraries and dedicated community, contrasts with Flutter's rapidly growing ecosystem and vibrant developer community. These factors are key considerations for developers as they make informed choices based on project requirements, performance needs, language preferences, and available support within each framework's ecosystem.

Qt's offering of LTS support is crucial for applications that need long-term stability, such as those requiring FDA compliance without a large maintenance team – something Flutter does not provide. Open-source Qt includes LTS, though it is typically limited to about two years unless support packages supplement it. This contrasts with Flutter where the absence of LTS might complicate compliance for medical devices without substantial backing. 

Additionally, Qt is better suited for low-end hardware that requires software rendering and lacks a GPU. Flutter demands Vulkan, which restricts Flutter’s use in less capable environments. Qt also enables direct hardware access through C++, which simplifies the development of robust applications without relying on external plugins – described by some as "one-stop shopping." Conversely, Flutter's reliance on a vast array of plugins can introduce integration challenges.

Qt is often pre-integrated by board vendors, easing initial setup and enabling quick start-ups with "hello world" demonstrations. Philosophically, Qt is viewed as a well-architected "cathedral," providing a cohesive set of tools and libraries. In contrast, Flutter's modular approach, while flexible, may necessitate more effort to replace unsuitable components. 

Opting for Qt is recommended for complex projects that demand native performance and extensive functionalities, especially when such demands justify the associated licensing costs. But there are situations when Flutter is the best option. Flutter shines as the preferred choice in several use cases, particularly for projects facing budget constraints or where Qt's licensing costs are a concern. Flutter’s cost-effectiveness allows for efficient resource allocation, making it an attractive option for startups and organizations with limited budgets. 

Furthermore, Flutter excels in projects prioritizing rapid development and cross-platform consistency in UI. Its hot reload feature accelerates development cycles, enabling quick iterations and adjustments, while the single codebase approach ensures a uniform user experience across various platforms, enhancing usability and reducing development efforts. That’s one reason Flutter on embedded is gaining momentum in domains like the automotive IVI space.  

Overall, Flutter's combination of cost-effectiveness, rapid development capabilities, and cross-platform consistency positions it as a top contender for projects seeking efficient and streamlined development processes.

Making the Right Choice for Your Project

Both Qt and Flutter offer unique advantages depending on the specific needs and priorities of your project. Qt is renowned for its versatility and robustness, providing extensive libraries and native performance capabilities, which makes it ideal for complex applications requiring sophisticated functionalities and optimal performance. Qt is particularly suitable for intricate projects such as medical devices that demand native performance and advanced features. On the other hand, Flutter shines in projects emphasizing cost-effectiveness, rapid development, and high-performing, consistent UI across platforms.

At ICS, we appreciate how difficult it can be for organizations to choose the right framework and navigate the complexities of software development. Our expertise in both Qt and Flutter allows us to tailor solutions that align with your project goals and deliver exceptional results. Whether you need assistance with framework selection or software development – or both – ICS can help you create impactful applications that meet user expectations and drive business success. If you have a project in mind, reach out.

Download our on-demand webinar Using Flutter for Embedded, featuring an Automotive Grade Linux (AGL) IVI case study.