Jetpack Compose: The future of Android development?

The world of Android app development (and beyond) is always on the move, and those who want to be relevant and competitive must stay at the forefront of constant innovation. That's why it's time to take a closer look at a new set of tools that are currently making a significant mark on modern Android UI development with their transformative power. We are talking about Jetpack Compose!

Jetpack Compose: What makes it special

Let's start with a quick introduction. Jetpack Compose is a modern and increasingly popular tool from Google designed for UI development in the Android environment.

What makes it so unique? It allows for an easier and faster creation of interactive and responsive UI. Moreover, it demonstrates a huge potential to span the entire Android development ecosystem.

Traditional UI development methods often involve imperative coding and complex XML management. Jetpack Compose, however, leverages the power of Kotlin and allows developers to create applications in a composite and reactive approach.

It especially shows when creating complex UIs. Your appreciation of Compose grows with the difficulty of the task you face.

Who appreciates a modern framework

If you don't have any experience with Jetpack Compose, don't worry - it is relatively straightforward to get started with. In addition, developers quickly become familiar with the full set of tools thanks to the available setup guide.

Believe us when we say that with Compose, creating a custom UI using declarative syntax is a matter of minutes, hours at most, even for someone just starting with the framework.

Jetpack Compose tries to accommodate developers and allow them to handle even complex requirements effortlessly - from creating your own RecyclerView to designing dynamic chat application interfaces.

Main advantages of Jetpack Compose

• Flexibility and scalability even for complex UI visions
• Skillful use of and composition of composite functions 
• Simple process for creating interactive and visually appealing UI

But there is much more.

Composite functions in practice

In the image below, you can see a simple composite function forming a UI component.

Example of a composite function

One of the biggest advantages is the possibility to re-use it in a different composite function. To give you a specific example, we will focus on the setContent function, which sets the content for the MainActivity.

Example of a composite function

As a result, a "Hello Android" text component is added to the view hierarchy. No big deal.

Once you've worked your way through this part, nothing is stopping you from creating your own complex user interface.

Complex interface? Status management? A piece of cake!

Creating complex and dynamic user interfaces is tricky. Luckily, you can rejoice because this is where Jetpack Compose fully shines.

So instead of simple examples, let's explore the possibilities when dealing with demanding requirements. In the next example, we will define a composable function CardItem. 

Composable function definition

The function above defines the CardItem component to create the user interface of the card that the Column component is plugged into. More than that, it also contains two more components - text for the title and subtitle.

Jetpack Compose further excels in condition management.

In traditional Android development, the state is usually managed using Views and Activity/Fragment loops. Jetpack Compose directly provides tools for remembering functions or, for example mutableStateOf.

Managing checkboxes in Jetpack Compose

In this case, we use it to manage the status of the checkbox. You also have a wide range of pre-made user interface components that can be further customized and combined.

A wide range of pre-prepared components

When creating a custom RecyclerView, Compose uses the so-called LazyColumn. It is important to note that there is no such thing as an Adapter. All items are rendered and positioned directly by the framework.

As a result, the developer writes less code, hence reducing the room for potential errors.

The example below shows the Scaffold container that defines both the top panel and the floating action button. LazyColumn is thus enclosed in three text items.

The feature set allows you to create complex interfaces

By leveraging composite features, state management tools, and prebuilt UI components, developers can create user interfaces that are highly modular, reusable, and scalable.

Uncomplicated migration of code sets

Many developers struggle with integration into existing codebases. This process is even harder for large projects developed in traditional ways (e.g. XML).

However, there are several strategies to introduce Jetpack Compose into your existing projects step by step. And it's not rocket science.

The first option is gradually creating new functions or screens using Compose. It avoids the hassle of migrating everything at once and gives you a good introduction to the new framework.

The second and perhaps more convenient option is to use the AndroidView and ComposeView components to insert elements from Jetpack Compose into an existing layout.

By doing so, you can slowly migrate to the new framework while using the existing codebase for other features.

Be sure to appreciate these advanced topics

• Creating animations. Framework offers an arsenal of powerful tools that allow for the creation of smooth and responsive animations. These include the animate*AsState function, the Transition API, and the AnimationVector class.
  
  
• Custom layouts. Compose provides a flexible layout system for custom specialized components to meet application needs. It is suitable for almost anything.
  
  
• Navigation. The NavHost component and the NavController class play a major role here. Together, they are used to implement navigation between different screens or destinations of the application.
  
  
• Theming. A powerful theming system creates consistent and visually appealing user interfaces. Developers can customize everything from colours to typography in Compose.
  
  
• Testing. The framework provides APIs and comprehensive testing tools for user interfaces (including unit and integration tests) to ensure they function as reliably as expected.
  
  
• Performance Optimization. Advanced techniques and tools such as memory optimization, lazy composition and view recycling are also available. The resulting user interfaces are fast, responsive, and deliver on requirements.

Best practices in Jetpack Compose

To make Compose work as well and accurately as possible, it pays to follow best practices. 

They include, for example, minimizing the number of recompositions and using ‘remember’ statements so that the framework only accepts a bare minimum of external parameters.

It is worth considering the creation of your own reusable composite functions too, instead of the standard ones that are always accompanied by a huge list of parameters.

Developers should also have some experience with common design patterns and guidelines concerning accessibility (for example, for Material Design) so that the resulting interface is not only functional but also intuitive and user-friendly.

Needless to mention, even without these tips, you'll find your way around the environment quickly. Compose itself will guide you to the best solution!

What's the future of Jetpack Compose?

Jetpack Compose is a powerful tool for all Android developers looking to create attractive, powerful and dynamic user interfaces in a declarative way.

As the development of the framework is constantly moving forward, combined with its increasing extensibility, it is safe to say that Jetpack Compose is the future of Android UI development.

What does it mean?

• Continued growth and acceptance in the developer community
• Improving performance and stability
• Integration with other libraries (Navigation, Paging, WorkManager)
• Improving APIs to meet the needs of developers

Is Jetpack Compose already your regular development tool? Did our article make you try it out? If you would like more detailed information, check out our developer Mike's online meetup.

Do you have any questions for us? Do you need help with the development of (not only) customized Android applications? Contact us! Our team of developers is happy to handle any challenge.